FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Wai, MMK Welsh, PT Ma, WM AF Wai, MMK Welsh, PT Ma, WM TI Interaction of secondary circulations with the summer monsoon and diurnal rainfall over Hong Kong SO BOUNDARY-LAYER METEOROLOGY LA English DT Article ID CONVECTION; FLOW AB A complete yearly record (1988) of surface measurements is used to examine the atmospheric diurnal secondary circulations over the entire area of Hong Kong in conjunction with spatial and temporal variations of surface temperature, wind speed and rainfall. Evidence of atmospheric diurnal secondary circulations is found at 10 sites. The occurrence of a summer morning rainfall maximum over the coast results from the interaction of the large-scale summer monsoon and local mesoscale secondary circulations. The afternoon onshore secondary circulation accelerates the advection of warm, humid unstable air and, coupled with the upward orographic lifting, produces enhanced rainfall along windward mountain ridges. Dynamical and scaling considerations suggest that the blocking effect is negligible and the primary forcing mechanism is land-sea temperature difference, but terrain effects are also important. Although the secondary circulation system's strength and timing vary, the circulation behaves like a classic sea-land breeze circulation, complicated by superimposed mountain-valley breezes. C1 NATL WEATHER SERV,JACKSONVILLE,FL 32218. ROYAL OBSERV,HONG KONG,HONG KONG. RP Wai, MMK (reprint author), FLORIDA STATE UNIV,DEPT METEOROL,TALLAHASSEE,FL 32306, USA. NR 33 TC 8 Z9 8 U1 0 U2 3 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0006-8314 J9 BOUND-LAY METEOROL JI Bound.-Layer Meteor. PD NOV PY 1996 VL 81 IS 2 BP 123 EP 146 DI 10.1007/BF00119062 PG 24 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA WC524 UT WOS:A1996WC52400002 ER PT J AU Castro, JI AF Castro, JI TI Biology of the blacktip shark, Carcharhinus limbatus, off the southeastern United States SO BULLETIN OF MARINE SCIENCE LA English DT Article ID GROWTH; AGE; BAY AB The blacktip shark is a cosmopolitan species found throughout tropical and subtropical waters. It is common along the southeast coast of the United States, where it migrates northward to Georgia and the Carolinas in summer and southward to Florida in winter. The blacktip shark feeds on small bony fishes, primarily menhaden, and small elasmobranchs. Males mature between 1,425 and 1,450 mm TL, and all males over 1450 mm TL are mature. Females mature at about 1,560 mm TL. The reproductive cycle lasts 2 years and includes biennial ovulation with a 1-year gestation period. Mating and ovulation occur in Bulls Bay, South Carolina, from mid-May to early June. Parturition occurs the following year from early May to early June in the shallow coastal waters of the Carolinas. The blacktip shark is a viviparous, placental species. Implantation usually occurs during the 10th and 11th weeks of gestation when the embryos measure 178-194 mm TL. The young are born at about 550-600 mm TL during May and early June in the shallow water, coastal nurseries of Georgia and the Carolinas. The neonate stage lasts about a month. The young remain in the shallow water nurseries until fall. RP Castro, JI (reprint author), NATL MARINE FISHERIES SERV,SE FISHERIES SCI CTR,75 VIRGINIA BEACH DR,MIAMI,FL 33149, USA. NR 19 TC 107 Z9 122 U1 5 U2 24 PU ROSENSTIEL SCH MAR ATMOS SCI PI MIAMI PA 4600 RICKENBACKER CAUSEWAY, MIAMI, FL 33149 SN 0007-4977 J9 B MAR SCI JI Bull. Mar. Sci. PD NOV PY 1996 VL 59 IS 3 BP 508 EP 522 PG 15 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA VW934 UT WOS:A1996VW93400005 ER PT J AU Mesinger, F AF Mesinger, F TI Improvements in quantitative precipitation forecasts with the ETA regional model at the National Centers for Environmental Prediction: The 48-km upgrade SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID STEP-MOUNTAIN COORDINATE; ANALYSIS SYSTEM; PARAMETERIZATION; ATMOSPHERE; SCHEMES; IMPACT; NMC AB Since 9 June 1993, the eta coordinate regional model has been run twice daily at the National Centers for Environmental Prediction (NCEP, previously the National Meteorological Center) as the NCEP's ''early'' operational model. Its performance is regularly monitored in a variety of ways, with particular attention given to precipitation forecasts. Throughout this period, the eta model has demonstrated significantly increased accuracy in forecasting daily precipitation amounts compared to NCEP's Nested Grid Model (NGM). The model has shown a smaller but equally consistent advantage in skill against that of NCEP's global spectral model. Precipitation scores of these three operational models for the 6-month period March-August 1995 are presented. This interval is chosen because the 6-month-long periods September-February and March-August have been used in previous model comparisons and because an upgraded version of the eta model, run at 48-km resolution, was also regularly executed twice daily during the March-August 1995 period. It is thus included and highlighted in the present comparison. The 48-km eta carries cloud water as a prognostic variable and is coupled to a 12-h eta-based intermittent data assimilation system. It replaced the 80-km eta as the NCEP's early operational model on 12 October 1995. Compared to the then-operational 80-km eta, the 48-km eta has demonstrated substantially increased skill at all eight precipitation categories for which verifications are made. The increase in skill was greatest for the most intense precipitation, at the threshold of 2 in. (24 h)(-1). A 24-48-h forecast of accumulated precipitation, resulting from Hurricane Allison as it was crossing the extreme southeastern United States, is shown as an example of a successful forecast of intense precipitation by the 48-km model. Reasons for the advantage of the eta model over its predecessor, the NGM, are reviewed. The work in progress is outlined. C1 NATL CTR ENVIRONM PREDICT,UCAR VISITOR RES PROGRAM,WASHINGTON,DC. NR 39 TC 92 Z9 95 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD NOV PY 1996 VL 77 IS 11 BP 2637 EP 2649 DI 10.1175/1520-0477(1996)077<2637:IIQPFW>2.0.CO;2 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VW729 UT WOS:A1996VW72900002 ER PT J AU Lewis, JM AF Lewis, JM TI C.-G. Rossby: Geostrophic adjustment as an outgrowth of modeling the Gulf Stream SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID METEOROLOGY AB Carl-Gustaf Rossby (1898-1957) was chosen to head the first U.S. program in modem meteorology at the Massachusetts Institute of Technology (MIT) in 1928. The steps that led to this appointment are briefly reviewed as well as the academic environment at MIT in the early 1930s. It has been argued that Rossby's development as a research scientist was closely tied to his connection with oceanographers at the Woods Hole Oceanographic Institution. His work on geostrophic adjustment, an outgrowth of his research on the Gulf Stream, was marked by bold simplification of the governing dynamical equations. This allowed him to capture the essence of adjustments between pressure and velocity in unbalanced geophysical flow. His work on the adjustment problem is summarized and related to earlier work by Ekman and Margules. RP Lewis, JM (reprint author), NATL SEVERE STORMS LAB,1313 HALLEY CIRCLE,NORMAN,OK 73069, USA. NR 73 TC 2 Z9 2 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD NOV PY 1996 VL 77 IS 11 BP 2711 EP 2728 DI 10.1175/1520-0477(1996)077<2711:CGRGAA>2.0.CO;2 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VW729 UT WOS:A1996VW72900008 ER PT J AU Peng, GS Parson, RP AF Peng, GS Parson, RP TI Selective rovibrational energy transfer: A classical trajectory study of collisional energy redistribution in methyl radical SO CHEMICAL PHYSICS LA English DT Article ID SPHERICAL TOP MOLECULES; DIODE-LASER AB A classical trajectory study was performed on planar CH3 to investigate the cause of anomalous experimentally observed state selectivity in the collisional deactivation of CH4. Despite complicated and possibly chaotic dynamics in some of the vibrational states, one vibration was found stable enough to simulate the conditions of the experiment. The results agree with experiment and confirm that the selectivity is due to simple time-scale differences rather than the more commonly used energy-gap arguments. A detailed description of the nonstandard method for assigning the initial and final states is given. C1 UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. NATL INST STAND & TECHNOL,BOULDER,CO 80309. RP Peng, GS (reprint author), UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. NR 19 TC 0 Z9 0 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0301-0104 J9 CHEM PHYS JI Chem. Phys. PD NOV 1 PY 1996 VL 211 IS 1-3 BP 17 EP 31 DI 10.1016/0301-0104(96)00206-6 PG 15 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VR360 UT WOS:A1996VR36000002 ER PT J AU Levin, BC Chen, HY Reeder, DJ AF Levin, BC Chen, HY Reeder, DJ TI A human mitochondrial DNA standard reference material for quality control in identification, medical diagnosis, and mutational detection. SO CLINICAL CHEMISTRY LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. GEOCENTERS INC,NEWTON,MA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER ASSOC CLINICAL CHEMISTRY PI WASHINGTON PA 2101 L STREET NW, SUITE 202, WASHINGTON, DC 20037-1526 SN 0009-9147 J9 CLIN CHEM JI Clin. Chem. PD NOV PY 1996 VL 42 IS 11 BP 22 EP 22 PG 2 WC Medical Laboratory Technology SC Medical Laboratory Technology GA VQ332 UT WOS:A1996VQ33200058 ER PT J AU Gills, TE May, WE AF Gills, TE May, WE TI Comments concerning report of defective NIST SRM 909a vials SO CLINICAL CHEMISTRY LA English DT Letter C1 NATL INST STAND & TECHNOL,CHEM SCI & TECHNOL LAB,DIV ANALYT CHEM,GAITHERSBURG,MD 20899. RP Gills, TE (reprint author), NATL INST STAND & TECHNOL,STAND REFERENCE MAT PROGRAM,BLDG 202,RM 112,GAITHERSBURG,MD 20899, USA. NR 2 TC 2 Z9 2 U1 0 U2 0 PU AMER ASSOC CLINICAL CHEMISTRY PI WASHINGTON PA 2101 L STREET NW, SUITE 202, WASHINGTON, DC 20037-1526 SN 0009-9147 J9 CLIN CHEM JI Clin. Chem. PD NOV PY 1996 VL 42 IS 11 BP 1878 EP 1878 PG 1 WC Medical Laboratory Technology SC Medical Laboratory Technology GA VQ332 UT WOS:A1996VQ33200026 PM 8906094 ER PT J AU Smyth, KC Shaddix, CR AF Smyth, KC Shaddix, CR TI The elusive history of (m)over-bar=1.57-0.56i for the refractive index of soot SO COMBUSTION AND FLAME LA English DT Review ID TURBULENT-DIFFUSION FLAMES; EMISSION ABSORPTION-MEASUREMENTS; LIGHT-SCATTERING MEASUREMENTS; LASER-INDUCED INCANDESCENCE; LONG RESIDENCE TIMES; PREMIXED FLAMES; OPTICAL-PROPERTIES; VOLUME FRACTION; QUANTITATIVE MEASUREMENTS; RADIATIVE PROPERTIES RP Smyth, KC (reprint author), NIST,BLDG & FIRE RES LAB,GAITHERSBURG,MD 20899, USA. NR 133 TC 123 Z9 129 U1 1 U2 10 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 0010-2180 J9 COMBUST FLAME JI Combust. Flame PD NOV PY 1996 VL 107 IS 3 BP 314 EP 320 DI 10.1016/S0010-2180(96)00170-8 PG 7 WC Thermodynamics; Energy & Fuels; Engineering, Multidisciplinary; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA VP944 UT WOS:A1996VP94400011 ER PT J AU Bullard, JW Garboczi, EJ AF Bullard, JW Garboczi, EJ TI A lattice model for solid-state sintering: Simple particle arrays - Comment SO COMPUTATIONAL MATERIALS SCIENCE LA English DT Editorial Material ID CURVATURE C1 UNIV ILLINOIS,DEPT MAT SCI & ENGN,URBANA,IL 61801. NATL INST STAND & TECHNOL,BLDG MAT DIV,GAITHERSBURG,MD 20899. NR 5 TC 0 Z9 0 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-0256 J9 COMP MATER SCI JI Comput. Mater. Sci. PD NOV PY 1996 VL 6 IS 4 BP 350 EP 352 DI 10.1016/0927-0256(96)00042-0 PG 3 WC Materials Science, Multidisciplinary SC Materials Science GA VT794 UT WOS:A1996VT79400008 ER PT J AU Tewary, VK Berger, JR AF Tewary, VK Berger, JR TI Elastic Green's function for a bimaterial composite solid containing a crack inclined to the interface SO COMPUTATIONAL MECHANICS LA English DT Article ID BOUNDARY-ELEMENT ANALYSIS; STRESS; SINGULARITIES; EXTENSION AB An analytical closed-form expression is derived for the elastic Green's function of a bimaterial composite solid containing a planar interface and a straight crack inclined at an arbitrary angle with the interface. The crack tip is assumed to be at the interface. Both the constituent materials of the composite are assumed to anisotropic. The Green's function satisfies the interfacial boundary conditions of continuous tractions and displacements, and zero tractions at the crack surfaces. The boundary conditions are satisfied by using the virtual force technique. The determination of the virtual forces requires solutions of a Hilbert problem which is obtained by using an orthogonal complex transform. The method is illustrated by applying it to a copper/nickel composite. The Green's function should be useful in the boundary-element method of calculating the stress and the displacement field in the solid. C1 COLORADO SCH MINES,DIV ENGN,GOLDEN,CO 80401. NATL INST STAND & TECHNOL,DIV MAT RELIABIL,BOULDER,CO 80303. RI Berger, John/F-5169-2010 NR 21 TC 1 Z9 1 U1 0 U2 1 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0178-7675 J9 COMPUT MECH JI Comput. Mech. PD NOV PY 1996 VL 19 IS 1 BP 41 EP 48 DI 10.1007/BF02757782 PG 8 WC Mathematics, Interdisciplinary Applications; Mechanics SC Mathematics; Mechanics GA VX392 UT WOS:A1996VX39200004 ER PT J AU Gorti, SR Sriram, RD AF Gorti, SR Sriram, RD TI From symbol to form: A framework for conceptual design SO COMPUTER-AIDED DESIGN LA English DT Article DE conceptual design; symbol-form mapping; knowledge-based systems; knowledge representation; constraint satisfaction AB This paper presents the design of a software framework for conceptual design, II develops an approach to mapping an evolving symbolic description of design into a geometric description. The distinct elements of the symbol-form mapping are: (a) deriving spatial relationships between objects as a consequence of the functional relationships; (b) instantiating alternative feasible solutions subject to these relationships; and (c) presenting the evolving descriptions of geometry. Computational support for each of these elements is provided within a conceptual design framework. The paper presents components of the framework, explicitly identifies interactions between these components, and explains how these interactions are developed into an integrated framework. It presents the rationale for the design decisions made in the framework, An example is presented to clarify the approach adopted. The applicability of the approach is then discussed. Copyright (C) 1996 Published by Elsevier Science Ltd C1 NIST,MFG ENGN LAB,MSD,GAITHERSBURG,MD 20899. RP Gorti, SR (reprint author), SPECTROGRAPH CORP,9707 WAPLES ST,SAN DIEGO,CA 92122, USA. NR 22 TC 36 Z9 48 U1 0 U2 6 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0010-4485 J9 COMPUT AIDED DESIGN JI Comput.-Aided Des. PD NOV PY 1996 VL 28 IS 11 BP 853 EP 870 PG 18 WC Computer Science, Software Engineering SC Computer Science GA VJ712 UT WOS:A1996VJ71200002 ER PT J AU Graham, DW Castillo, PR Lupton, JE Batiza, R AF Graham, DW Castillo, PR Lupton, JE Batiza, R TI Correlated He and Sr isotope ratios in South Atlantic near-ridge seamounts and implications for mantle dynamics SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Article DE He-4/He-3; seamounts; mantle; mid-ocean ridge basalts; Mid-Atlantic Ridge ID CHEMICAL GEODYNAMICS; OCEANIC BASALTS; TRACE-ELEMENT; EARTHS MANTLE; HELIUM; PLUMES; GEOCHEMISTRY; EVOLUTION; HOTSPOT; CONSTRAINTS AB He-4/He-3 and Sr-87/Sr-86 ratios are highly anti-correlated for a suite of seamount glasses from both sides of the Mid-Atlantic Ridge at 26 degrees S; the linear correlation coefficient (r(2)) is 0.99 for 5 localities at 3 different seamounts. The seamounts are located on crust up to 2.5 myr old, and have He-4/He-3 as low as 65,400 (He-3/He-4 = 11 R(A)) and Sr-87/Sr-86 as high as 0.70350. These isotopic values are significantly lower and higher, respectively, than those for basaltic glasses recovered from 13 localities along the adjacent ridge axis, where the lowest He-4/He-3 ratio is 92,000 (He-3/He-4 = 7.8 R(A)) and the highest (87)/(86) Sr is 0.70258. Geophysical studies and the small (1-2%) degree of helium isotope disequilibrium between vesicles and glass for three seamount lavas suggest that the seamounts formed on or near the ridge axis. Because no off-ridge hotspots are present in this area, formation of the seamounts probably involved capture by the ridge of a passive mantle heterogeneity of 'blob' during rift propagation and tectonic evolution of the Moore fracture zone. The He-Sr-Nd-Pb isotopic results for the seamounts show a general trend toward compositions observed for the Reunion hotspot in the Indian Ocean. Collectively, the seamount and ridge axis results are somewhat enigmatic. In addition to the highly correlated He and Sr isotopes at the seamounts, a fair correlation exists between He and Nd isotopes (r(2) = 0.70). in contrast, a correlation between He and Pb isotopes is absent for the seamount glasses, while an independent, positive correlation exists between He-4/He-3 and Pb-206/Pb-204 for axial lavas. Apparently, different processes are responsible for the seamount He-Sr-Nd isotope relationships and for the nearby ridge He-Pb isotope relationship. If these relations are only of local significance and result from complications inherent in multi-stage mixing of more than two mantle components, then they imply that the upper mantle may contain domains with variable 4He/ 3He ratios, in some cases significantly lower than 80,000 (He-3/He-4 > 9 R(A)), On the other hand, binary mixing adequately explains the linear He-Sr isotope trend in the seamount lavas. This linear trend suggests similar He-3/Sr-86 ratios in the local MORE mantle source and in the source region of the low He-4/He-3 blob, which is most likely the lower mantle or the transition zone region. This similarity in He-3/Sr-86 is inconsistent with a lower mantle 3 He/Sr-86 ratio that exceeds the upper mantle ratio by at least a factor of 501 deduced from geochemical models of mantle evolution. Consequently, rare gas models involving a steady-state upper mantle and quasi-closed lower mantle may be inappropriate if applied at length scales on the order of similar to 100 km, characteristic of mid-ocean ridge segments. C1 UNIV CALIF SAN DIEGO,SCRIPPS INST OCEANOG,LA JOLLA,CA 92093. HATFIELD MARINE SCI CTR,NOAA,PACIFIC MARINE ENVIRONM LAB,NEWPORT,OR 97365. UNIV HAWAII,DEPT GEOL & GEOPHYS,HONOLULU,HI 96822. RP Graham, DW (reprint author), OREGON STATE UNIV,COLL OCEAN & ATMOSPHER SCI,CORVALLIS,OR 97331, USA. OI Graham, David/0000-0002-7411-1905 NR 64 TC 29 Z9 29 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0012-821X J9 EARTH PLANET SC LETT JI Earth Planet. Sci. Lett. PD NOV PY 1996 VL 144 IS 3-4 BP 491 EP 503 DI 10.1016/S0012-821X(96)00172-0 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA VZ890 UT WOS:A1996VZ89000016 ER PT J AU Taylor, BL Wade, PR Stehn, RA Cochrane, JF AF Taylor, BL Wade, PR Stehn, RA Cochrane, JF TI A Bayesian approach to classification criteria for spectacled eiders SO ECOLOGICAL APPLICATIONS LA English DT Article DE Bayesian inference; decision analysis; extinction; risk classification; spectacled eider; trends; uncertainty ID CONSERVATION; MANAGEMENT; POWER AB To facilitate decisions to classify species according to risk of extinction, we used Bayesian methods to analyze trend data for the Spectacled Elder an arctic sea duck. Trend data from three independent surveys of the Yukon-Kuskokwim Delta were analyzed individually and in combination to yield posterior distributions for population growth rates. We used classification criteria developed by the recovery team for Spectacled Elders that seek to equalize errors of under- or overprotecting the species. We conducted both a Bayesian decision analysis and a frequentist (classical statistical inference) decision analysis. Bayesian decision analyses are computationally easier, yield basically the same results, and yield results that are easier to explain to nonscientists. With the exception of the aerial survey analysis of the 10 most recent years, both Bayesian and frequentist methods indicated that an endangered classification is warranted. The discrepancy between surveys warrants further research, Although the trend data are abundance indices, we used a preliminary estimate of absolute abundance to demonstrate how to calculate extinction distributions using the joint probability distributions for population growth rate and Variance in growth rate generated by the Bayesian analysis, Recent apparent increases in abundance highlight the need for models that apply to declining and then recovering species. C1 ALASKA SCI CTR, NATL BIOL SERV, ANCHORAGE, AK 99503 USA. US FISH & WILDLIFE SERV, ANCHORAGE, AK 99501 USA. NATL MARINE MAMMAL LAB, OFF PROTECTED RESOURCES, NATL MARINE FISHERIES SERV, SEATTLE, WA 98115 USA. RP Taylor, BL (reprint author), SW FISHERIES SCI CTR, POB 271, LA JOLLA, CA 92038 USA. NR 34 TC 38 Z9 39 U1 1 U2 7 PU ECOLOGICAL SOC AMER PI WASHINGTON PA 1990 M STREET NW, STE 700, WASHINGTON, DC 20036 USA SN 1051-0761 J9 ECOL APPL JI Ecol. Appl. PD NOV PY 1996 VL 6 IS 4 BP 1077 EP 1089 DI 10.2307/2269592 PG 13 WC Ecology; Environmental Sciences SC Environmental Sciences & Ecology GA VR856 UT WOS:A1996VR85600013 ER PT J AU Hobson, ES Chess, JR AF Hobson, ES Chess, JR TI Examination of a great abundance of filefish, Pervagor spilosoma, in Hawaii SO ENVIRONMENTAL BIOLOGY OF FISHES LA English DT Article DE coral-reef fish; recruitment; food habits; parasites; selective mortality ID BEHAVIOR; FISH AB The endemic filefish Pervagor spilosoma appeared in exceptionally large numbers throughout the major Hawaiian Islands during the spring of 1985 and remained abundant through 1988. We examined this occurrence with a perspective gained from studies of reef communities at the Island of Hawaii by one or both of us during most years from 1969 to 1994. P. spilosoma is known to vary in numbers, but such great abundances are rare. Although the species is considered a reef fish, individuals constituting the abundance were mostly in the water column, and spread from coastal reefs to the pelagic zone offshore. One might assume they represented an extraordinary recruitment of pelagic juveniles in the process of shifting to benthic habits, but our data indicate a more complex situation. Individuals in the water column tended to be larger than individuals near the reef, and although the former were feeding on plankton when collected, many had shifted to planktivory from earlier feeding on the benthos. Also, many in the water column were ailing, with moribund and dead individuals common, and these tended to carry parasites of types known to induce their hosts to rise toward the surface. We suggest that the great number of filefish we observed above near-shore reefs represented the shoreward fringe of a vast pool of individuals, varied in age, that had accumulated during the exceptionally long pelagic-juvenile period that is characteristic of tetraodontiforms. RP Hobson, ES (reprint author), SW FISHERIES SCI CTR,TIBURON LAB,3150 PARADISE DR,TIBURON,CA 94920, USA. NR 17 TC 6 Z9 6 U1 0 U2 2 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0378-1909 J9 ENVIRON BIOL FISH JI Environ. Biol. Fishes PD NOV PY 1996 VL 47 IS 3 BP 269 EP 278 DI 10.1007/BF00000499 PG 10 WC Ecology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA VM470 UT WOS:A1996VM47000005 ER PT J AU Kim, GB Tanabe, S Tatsukawa, R Loughlin, TR Shimazaki, K AF Kim, GB Tanabe, S Tatsukawa, R Loughlin, TR Shimazaki, K TI Characteristics of butyltin accumulation and its biomagnification in Steller sea lion (Eumetopias jubatus) SO ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY LA English DT Article DE butyltin; Steller sea lions; age trend; temporal trend; biomagnification ID TRI-NORMAL-BUTYLTIN; DI-NORMAL-BUTYLTIN; ORGANOTIN COMPOUNDS; MARINE MAMMALS; TRIBUTYLTIN; IMPOSEX; SEDIMENT; WATER; BIOCONCENTRATION; ORGANOCHLORINES AB The present study was conducted to examine sex difference, age, and temporal trends of butyltin accumulation and its biomagnification in Steller sea lion (Eumetopias jubatus) collected from Alaska, USA, during 1976-1985 and from Hokkaido, Japan, during 1994-1995. Average concentration of total butyltin compounds (Sigma BTs) in the liver of Steller sea lion from Alaska (19 ng/g wet weight) was much lower than those from western and eastern Hokkaido, Japan (150 and 220 ng/g), respectively. This result suggests that Japanese coastal waters are contaminated with BTs in comparison with those of Alaska. In most samples, dibutyltin (DBT) residues were retained at higher levels than tributyltin (TBT), suggesting the degradation of TBT to DBT in the liver. Sex difference and age-dependent accumulation of BTs residues were not found in Steller sea lion. Similarly, no prominent temporal trend in BT concentrations was observed between 1976 and 1985. Nevertheless, the annual consumption of organotin compound was doubled in the United States during the same period. These results suggest that the butyltin compounds are degraded faster than the intake from diet in Steller sea lion. The biomagnification factor of BTs in Steller sea lion was low (0.15-4.6; mean, 0.6), indicating that this animal is unlikely to magnify BTs due to rapid degradation and excretion. C1 EHIME UNIV,DEPT ENVIRONM CONSERVAT,MATSUYAMA,EHIME 790,JAPAN. NOAA,NATL MARINE FISHERIES SERV,NATL MARINE MAMMAL LAB,SEATTLE,WA 98115. HOKKAIDO UNIV,RES INST N PACIFIC FISHERIES,HAKODATE,HOKKAIDO 041,JAPAN. RI Tanabe, Shinsuke/G-6950-2013 NR 44 TC 32 Z9 33 U1 1 U2 5 PU SETAC PRESS PI PENSACOLA PA 1010 NORTH 12TH AVE, PENSACOLA, FL 32501-3370 SN 0730-7268 J9 ENVIRON TOXICOL CHEM JI Environ. Toxicol. Chem. PD NOV PY 1996 VL 15 IS 11 BP 2043 EP 2048 DI 10.1897/1551-5028(1996)015<2043:COBAAI>2.3.CO;2 PG 6 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA VR118 UT WOS:A1996VR11800023 ER PT J AU Weber, SF Lippiatt, BC AF Weber, SF Lippiatt, BC TI Cost-effective compliance with life safety codes SO FIRE TECHNOLOGY LA English DT Article DE building codes; building economics; economic analysis; fire safety; health care facilities; hospitals; life safety codes; linear programming; mathematical programming; optimization AB ALARM is personal computer software that helps building managers and fire safety engi neers achieve cost-effective compliance with the widely used NFPA 101, Lire Safety Code(R). The software currently supports health-care occupancy analysis. Through the equivalency provision of the code, ALARM implements a goal-oriented, or performance-based, approach to code compliance. The software generates a set of alternative code compliance strategies and their estimated construction costs. Engineering judgment is then applied to select the most appropriate code compliance strategy based on both cost and design considerations. The software offers a code-compliance optimizer, a compre hensive file manager, and a full-screen data editor. Since 1981, the optimization method used in ALARM has been field-tested in 89 hospitals (17,898 beds). For this sample, the least-cost solution identified by the software was, on average, 41 percent less expensive than the prescriptive solution. This represents a potential cost savings of $2,116 per bed or more than $37 million. Future versions of ALARM could address other building occupancies. RP Weber, SF (reprint author), NATL INST STAND & TECHNOL,BLD & FIRE RES LAB,GAITHERSBURG,MD 20899, USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU NATIONAL FIRE PROTECTION ASSOC PI QUINCY PA ONE BATTERYMARCH PK, QUINCY, MA 02269 SN 0015-2684 J9 FIRE TECHNOL JI Fire Technol. PD NOV-DEC PY 1996 VL 32 IS 4 BP 291 EP 296 DI 10.1007/BF01037739 PG 6 WC Engineering, Multidisciplinary; Materials Science, Multidisciplinary SC Engineering; Materials Science GA VV159 UT WOS:A1996VV15900003 ER PT J AU Gregg, TKP Chadwick, WW AF Gregg, TKP Chadwick, WW TI Submarine lava-flow inflation: A model for the formation of lava pillars SO GEOLOGY LA English DT Article ID SHEET FLOWS; MORPHOLOGY AB Lava pillars are commonly observed in volcanic terrains at mid-ocean ridges and are unique to the submarine volcanic environment; they are hollow pipes that extend from the base of a lava flow to remnants of its collapsed upper crust. Pillars can be as tall as 5 m and have outer diameters typically between 0.5 and 2 m. Previous models proposed that they form in thick, fluid, fast-moving sheet flows. We present a new model for pillar formation based on sea-floor observations, and on results from laboratory and numerical models, in which lava pillars form within initially thin (<0.3 m), slow moving lobate lava flows as gaps between neighboring lobes. Water escaping from beneath the how acts to locally cool and thicken the crust at the gaps. Pillars attain their full height during subsequent lava-flow inflation. As the flow thickens, pillars that do not continue to channel water are melted and resorbed into the molten flow interior. Pillars are typically preserved at the margins of ponded lava flows where the flow interior is relatively stagnant and less efficient at remelting pillars, and where seawater is more accessible for circulation through the flow. C1 OREGON STATE UNIV,HATFIELD MARINE SCI CTR,NOAA,NEWPORT,OR 97365. RP Gregg, TKP (reprint author), WOODS HOLE OCEANOG INST,DEPT GEOL & GEOPHYS,WOODS HOLE,MA 02543, USA. NR 15 TC 41 Z9 42 U1 0 U2 3 PU GEOLOGICAL SOC AMERICA PI BOULDER PA PO BOX 9140 3300 PENROSE PLACE, BOULDER, CO 80301 SN 0091-7613 J9 GEOLOGY JI Geology PD NOV PY 1996 VL 24 IS 11 BP 981 EP 984 DI 10.1130/0091-7613(1996)024<0981:SLFIAM>2.3.CO;2 PG 4 WC Geology SC Geology GA VW098 UT WOS:A1996VW09800005 ER PT J AU Ross, RJ Otterman, J Starr, DO Elliott, WP Angell, JK Susskind, J AF Ross, RJ Otterman, J Starr, DO Elliott, WP Angell, JK Susskind, J TI Regional trends of surface and tropospheric temperature and evening-morning temperature difference in northern latitudes: 1973-93 SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID AIR-TEMPERATURE AB Trends for the 21-year period 1973-1993 of temperatures at the surface and in the troposphere were analyzed from radiosonde observations in eight north-latitude regions. The seasonal consistency of the surface and tropospheric trends of temperature and evening-morning temperature difference was examined for these regions. In most seasons the surface temperature trends were positive in Eurasia and western N. America but were negative in central N. America and eastern Canada. The regions with sizable and statistically significant surface temperature trends usually had significant tropospheric trends up to 500 mb and sometimes to 300 mb. An exception was central Asia, where the strong warming was confined below 850 mb. The significant tropospheric trends showed a tendency to de crease in magnitude with height. Trends of the evening minus morning temperature difference were also analyzed in two sectors, Canada and Russia, where the radiosonde launches occurred at 5am and pm +/-2hrs. Trends were fairly consistent in sign between the surface and lower troposphere in both sectors and up to 300 mb over Canada. Most Canadian trends were significant and represented a decreasing range between evening and morning temperatures. Significant Russian trends were primarily in summer. C1 NASA,GODDARD SPACE FLIGHT CTR,ATMOSPHERES LAB,GREENBELT,MD 20771. RP Ross, RJ (reprint author), NOAA,AIR RESOURCES LAB,1315 E WEST HWY,SILVER SPRING,MD 20910, USA. NR 9 TC 19 Z9 20 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD NOV 1 PY 1996 VL 23 IS 22 BP 3179 EP 3182 DI 10.1029/96GL03076 PG 4 WC Geosciences, Multidisciplinary SC Geology GA VQ924 UT WOS:A1996VQ92400028 ER PT J AU Keim, ER Fahey, DW DelNegro, LA Woodbridge, EL Gao, RS Wennberg, PO Cohen, RC Stimpfle, RM Kelly, KK Hintsa, EJ Wilson, JC Jonsson, HH Dye, JE Baumgardner, D Kawa, SR Salawitch, RJ Proffitt, MH Loewenstein, M Podolske, JR Chan, KR AF Keim, ER Fahey, DW DelNegro, LA Woodbridge, EL Gao, RS Wennberg, PO Cohen, RC Stimpfle, RM Kelly, KK Hintsa, EJ Wilson, JC Jonsson, HH Dye, JE Baumgardner, D Kawa, SR Salawitch, RJ Proffitt, MH Loewenstein, M Podolske, JR Chan, KR TI Observations of large reductions in the NO/NOy ratio near the mid-latitude tropopause and the role of heterogeneous chemistry SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID IN-SITU MEASUREMENTS; LOWER STRATOSPHERE; SUPERSONIC AIRCRAFT; INSITU MEASUREMENTS; REACTIVE NITROGEN; REMOVAL; OH; AEROSOLS; EMISSION; RADICALS AB During the 1993 NASA Stratospheric Photochemistry, Aerosols and Dynamics Expedition (SPADE), anomalously low nitric oxide (NO) was found in a distinct sunlit layer located above the mid-latitude tropopause. The presence of a significant amount of reactive nitrogen (NOy) in the layer implies the systematic removal of NO, which Is without precedent in stratospheric irt situ observations. Large increases in measured chlorine monoxide (ClO) and the hydroperoxyl radical (HO2) also were observed in the layer. Heterogeneous reaction rate constants of chlorine nitrate (ClONO2) with hydrogen chloride (HCl) and H2O to form nitric acid (HNO3) on sulfate aerosol are enhanced in the NO removal layer by local increases in H2O and aerosol surface area. The associated conversion of NOx (= NO + NO2) to HNO3 is the most likely cause of the observed low NO and NOx/NOy values and high ClO values. C1 UNIV COLORADO,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. HARVARD UNIV,DEPT CHEM,CAMBRIDGE,MA 02138. NATL CTR ATMOSPHER RES,BOULDER,CO 80307. NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. CALTECH,JET PROP LAB,PASADENA,CA 91109. NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. UNIV DENVER,DEPT ENGN,DENVER,CO 80208. RP Keim, ER (reprint author), NOAA,AERON LAB,325 BROADWAY,BOULDER,CO 80303, USA. RI Salawitch, Ross/B-4605-2009; Cohen, Ronald/A-8842-2011; Wennberg, Paul/A-5460-2012; Kawa, Stephan/E-9040-2012; Gao, Ru-Shan/H-7455-2013; Fahey, David/G-4499-2013 OI Salawitch, Ross/0000-0001-8597-5832; Cohen, Ronald/0000-0001-6617-7691; Fahey, David/0000-0003-1720-0634 NR 21 TC 32 Z9 35 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD NOV 1 PY 1996 VL 23 IS 22 BP 3223 EP 3226 DI 10.1029/96GL02593 PG 4 WC Geosciences, Multidisciplinary SC Geology GA VQ924 UT WOS:A1996VQ92400039 ER PT J AU Moen, J Evans, D Carlson, HC Lockwood, M AF Moen, J Evans, D Carlson, HC Lockwood, M TI Dayside moving auroral transients related to LLBL dynamics SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID BOUNDARY-LAYER; MAGNETOSPHERE; FIELD; RECONNECTION; IONOSPHERE; PARTICLES; PLASMA; MODEL; CLEFT; CUSP AB The NOAA-12 satellite skimmed through a region of dayside auroral activity over Svalbard on January 12, 1992. A sequence of auroral forms from two separated onset sites in the postnoon sector drifted westward towards magnetic noon. The auroral forms were associated with a population of injected magnetosheath plasma mixed with a secondary component of magnetospheric ions (>30 keV) that is a key signature of the low-latitude boundary layer (LLBL). The direction of motion of the cleft auroral forms and the basic features of the NOAA particle spectrograms indicate that the transients are related to LLBL on open field lines. The auroral transients are consistent with footprints of reconnection at the dayside magnetopause which is both patchy in space and sporadic in time. C1 NOAA,SPACE ENVIRONM CTR,BOULDER,CO 80303. RUTHERFORD APPLETON LAB,DIDCOT OX11 0QX,OXON,ENGLAND. PHILLIPS LAB,CAG,BEDFORD,MA 01731. RP Moen, J (reprint author), UNIV COURSES SVALBARD,UNIS,POV 156,N-9170 LONGYEARBYEN,NORWAY. RI Lockwood, Mike/G-1030-2011 OI Lockwood, Mike/0000-0002-7397-2172 NR 13 TC 26 Z9 26 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD NOV 1 PY 1996 VL 23 IS 22 BP 3247 EP 3250 DI 10.1029/96GL02766 PG 4 WC Geosciences, Multidisciplinary SC Geology GA VQ924 UT WOS:A1996VQ92400045 ER PT J AU Williams, DF Olyslager, F AF Williams, DF Olyslager, F TI Modal cross power in quasi-TEM transmission lines SO IEEE MICROWAVE AND GUIDED WAVE LETTERS LA English DT Article AB This letter examines modal cross power in electromagnetic transmission lines, It shows that the cross powers of nearly degenerate modes may be large in quasi-TEM multiconductor transmission lines typical of modern electronic circuits at moderate and low microwave frequencies, The letter develops simple expressions to estimate the magnitude of these cross powers from the ''power-normalized'' conductor impedance and admittance matrices of the lines. RP Williams, DF (reprint author), NATL INST STAND & TECHNOL,BOULDER,CO 80303, USA. NR 13 TC 5 Z9 5 U1 1 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1051-8207 J9 IEEE MICROW GUIDED W JI IEEE Microw. Guided Wave Lett. PD NOV PY 1996 VL 6 IS 11 BP 413 EP 415 DI 10.1109/75.541457 PG 3 WC Engineering, Electrical & Electronic SC Engineering GA VP676 UT WOS:A1996VP67600007 ER PT J AU DeLyser, RR Holloway, CL Johnk, RT Ondrejka, AR Kanda, M AF DeLyser, RR Holloway, CL Johnk, RT Ondrejka, AR Kanda, M TI Figure of merit for low frequency anechoic chambers based on absorber reflection coefficients SO IEEE TRANSACTIONS ON ELECTROMAGNETIC COMPATIBILITY LA English DT Article ID ARRAYS; MODEL; WEDGE AB Return loss as a function of frequency acid angle of incidence is studied to determine the effectiveness of the absorbing material used in an anechoic chamber, This alone is not enough to determine a figure of merit for an anechoic chamber or to compare the figure of merit for one anechoic chamber to that of another, While the information gained from return loss calculations and measurements as a function of angle of incidence is valuable, an overall measure of anechoic chamber effectiveness is necessary in order to compare different designs, In this paper, a new chamber figure of merit which is based on the decay time of the chamber is introduced, This decay time is, in turn, based on the average power absorbed by the chamber walls, The resulting model is simple and does not require intensive numerical computation, Calculations of the figure of merit for anechoic chambers which contain different types of absorbing materials are shown, and calculated and measured values of decay time for a primary standards calibrations facility are compared. C1 NATL TELECOMMUN & INFORMAT ADM,INST TELECOMMUN SCI,DEPT COMMERCE,BOULDER,CO 80303. NATL INST STAND & TECHNOL,FIELDS & INTERFERENCE METROL GRP,DIV ELECTROMAGNET FIELDS,BOULDER,CO. RP DeLyser, RR (reprint author), UNIV DENVER,DEPT ENGN,DENVER,CO 80208, USA. NR 36 TC 10 Z9 10 U1 1 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9375 J9 IEEE T ELECTROMAGN C JI IEEE Trans. Electromagn. Compat. PD NOV PY 1996 VL 38 IS 4 BP 576 EP 584 DI 10.1109/15.544312 PG 9 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA VU487 UT WOS:A1996VU48700004 ER PT J AU Hill, DA AF Hill, DA TI A reflection coefficient derivation for the Q of a reverberation chamber SO IEEE TRANSACTIONS ON ELECTROMAGNETIC COMPATIBILITY LA English DT Article ID MODE AB A reflection coefficient method is used to derive the quality factor (Q) of reverberation chambers of arbitrary shape, The results are applicable to walls of general materials, but reduce to the previous result for highly conducting walls with small skin depth, The reflection coefficient method is also used to derive the decay time of reverberation chambers. RP Hill, DA (reprint author), NATL INST STAND & TECHNOL,DIV ELECTROMAGNET FIELDS,BOULDER,CO 80303, USA. NR 9 TC 29 Z9 29 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9375 J9 IEEE T ELECTROMAGN C JI IEEE Trans. Electromagn. Compat. PD NOV PY 1996 VL 38 IS 4 BP 591 EP 592 DI 10.1109/15.544314 PG 2 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA VU487 UT WOS:A1996VU48700006 ER PT J AU Krska, JHY Yoon, JU Nee, JT Roitman, P Campisi, GJ Brown, GA Chung, JE AF Krska, JHY Yoon, JU Nee, JT Roitman, P Campisi, GJ Brown, GA Chung, JE TI A model for SIMOX buried-oxide high-field conduction SO IEEE TRANSACTIONS ON ELECTRON DEVICES LA English DT Article ID LOW-ENERGY; OXYGEN IMPLANTATION; DEFECT DENSITY; SILICON; TEMPERATURE; MECHANISM; GENERATION; FILMS AB A new model for SIMOX buried-oxide (BOX) high-field conduction which incorporates the role of silicon islands and BOX nonstoichiometry is presented, For single-implant SIMOX BOX high-field conduction, the onset E-field for both positive and negative applied bias is much lower than the expected onset E-field for that of thermal oxide, In addition, the onset E-field for injection from the substrate is lower than for injection from the top-silicon. We propose that conduction by electron injection from the top interface is due to Fowler-Nordheim tunneling with oxide-nonstoichiometry-induced modification of the effective barrier-height, Conduction by electron injection from the bottom interface is due to a two-step Fowler-Nordheim tunneling mechanism with cathode E-field enhancement caused by the presence of silicon islands located near the oxide-substrate interface of single-implant SIMOX. These mechanisms were verified using numerical simulation, electrical, and physical measurements, A modified Fowler-Nordheim equation can be used to model BOX conduction through the addition of three parameters, K-e, k(a), and phi(BOX). The E-field enhancement factors (k(c) - and k(a)) can be directly correlated to silicon island shape, location and density, while the effective barrier-height (phi(BOX)) can be correlated to BOX nonstoichiometry, Monitoring these parameters has potential use as a simple method for SIMOX BOX quality control. C1 NIST,GAITHERSBURG,MD 20899. USN,RES LAB,WASHINGTON,DC 20375. TEXAS INSTRUMENTS INC,DALLAS,TX 75265. RP Krska, JHY (reprint author), MIT,CAMBRIDGE,MA 02139, USA. NR 38 TC 0 Z9 0 U1 1 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9383 J9 IEEE T ELECTRON DEV JI IEEE Trans. Electron Devices PD NOV PY 1996 VL 43 IS 11 BP 1956 EP 1964 DI 10.1109/16.543033 PG 9 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA VR356 UT WOS:A1996VR35600027 ER PT J AU Reeves, RR Leatherwood, S Jefferson, TA Curry, BE Henningsen, T AF Reeves, RR Leatherwood, S Jefferson, TA Curry, BE Henningsen, T TI Amazonian manatees, Trichechus inunguis, in Peru: Distribution, exploitation, and conservation status SO INTERCIENCIA LA English DT Article DE Amazonian manatee; Trichechus inungis; distribution; conservation; exploitation; Peru ID SIRENIA AB Amazonian manatees, Trichechus inunguis, are regularly hunted and trapped in the blackwater lakes and streams within and near the Pacaya-Samiria National Reserve in northeastern Peru. Much of the exploitation of manatees in this region is ancillary to the capture of paiche, Arapaima gigas. Manatees are also hunted opportunistically and taken incidentally in fishing gear elsewhere in Peru. While the current conservation status of manatees is uncertain, there is no doubt that their effective range has shrunk and their numbers have declined to a considerable extent. Although the species has been legally protected since 1973, exploitation for local consumption of meat has continued without any practical restrictions. If human activities are not managed to reduce their impact on manatees, these valuable animals will be extirpated throughout an ever-greater percentage of their range. C1 OCEAN PK CONSERVAT FDN,ABERDEEN,HONG KONG. SW FISHERIES SCI CTR,LA JOLLA,CA 92038. UNIV BREMEN,CTR TROP MARINE ECOL,D-2800 BREMEN 33,GERMANY. RP Reeves, RR (reprint author), OKAPI WILDLIFE ASSOCIATES,27 CHANDLER LANE,HUDSON,PQ J0P 1H0,CANADA. NR 28 TC 3 Z9 3 U1 2 U2 10 PU INTERCIENCIA PI CARACAS PA APARTADO 51842, CARACAS 1050A, VENEZUELA SN 0378-1844 J9 INTERCIENCIA JI Interciencia PD NOV-DEC PY 1996 VL 21 IS 6 BP 246 EP & PG 11 WC Ecology SC Environmental Sciences & Ecology GA VZ530 UT WOS:A1996VZ53000003 ER PT J AU Lanzante, JR AF Lanzante, JR TI Resistant, robust and non-parametric techniques for the analysis of climate data: Theory and examples, including applications to historical radiosonde station data SO INTERNATIONAL JOURNAL OF CLIMATOLOGY LA English DT Article DE robustness; non-parametric techniques; mean; median; variance; regression; trend analysis; correlation; rank tests; distributional tests; skewness; outliers; homogeneity; non-normality; discontinuities; signal-to-noise ratio; radiosonde data quality ID NORTHERN-HEMISPHERE; TIME-SERIES; TEMPERATURE; DISCONTINUITIES AB Basic traditional parametric statistical techniques are used widely in climatic studies for characterizing the level (central tendency) and variability of variables, assessing linear relationships (including trends), detection of climate change, quality control and assessment, identification of extreme events, etc. These techniques may involve estimation of parameters such as the mean (a measure of location), variance (a measure of scale) and correlation/regression coefficients (measures of linear association); in addition, it is often desirable to estimate the statistical significance of the difference between estimates of the mean from two different samples as well as the significance of estimated measures of association. The validity of these estimates is based on underlying assumptions that sometimes are not met by real climate data. Two of these assumptions are addressed here: normality and homogeneity (and as a special case statistical stationarity); in particular, contamination from a relatively few 'outlying values' may greatly distort the estimates. Sometimes these common techniques are used in order to identify outliers; ironically they may fail because of the presence of the outliers! Alternative techniques drawn from the fields of resistant, robust and non-parametric statistics are usually much less affected by the presence of 'outliers' and other forms of non-normality. Some of the theoretical basis for the alternative techniques is presented as motivation for their use and to provide quantitative measures for their performance as compared with the traditional techniques that they may replace. Although this work is by no means exhaustive, typically a couple of suitable alternatives are presented for each of the common statistical quantities/tests mentioned above. All of the technical details needed to apply these techniques are presented in an extensive appendix. With regard to the issue of homogeneity of the climate record, a powerful non-parametric technique is introduced for the objective identification of 'change-points' (discontinuities) in the mean. These may arise either naturally (abrupt climate change) or as the result of errors or changes in instruments, recording practices, data transmission, processing, etc. The change-point test is able to identify multiple discontinuities and requires no 'metadata' or comparison with neighbouring stations; these are important considerations because instrumental changes are not always documented and, particularly with regard to radiosonde observations, suitable neighbouring stations for 'buddy checks' may not exist. However, when such auxiliary information is available it may be used as independent confirmation of the artificial nature of the discontinuities. The application and practical advantages of these alternative techniques are demonstrated using primarily actual radiosonde station data and in a few cases using some simulated (artificial) data as well. The ease with which suitable examples were obtained from the radiosonde archive begs for serious consideration of these techniques in the analysis of climate data. RP Lanzante, JR (reprint author), PRINCETON UNIV,NOAA,GEOPHYS FLUID DYNAM LAB,PRINCETON,NJ 08542, USA. NR 36 TC 309 Z9 331 U1 2 U2 27 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0899-8418 J9 INT J CLIMATOL JI Int. J. Climatol. PD NOV PY 1996 VL 16 IS 11 BP 1197 EP 1226 DI 10.1002/(SICI)1097-0088(199611)16:11<1197::AID-JOC89>3.0.CO;2-L PG 30 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA WB220 UT WOS:A1996WB22000001 ER PT J AU Franaszek, M Simiu, E AF Franaszek, M Simiu, E TI Noise-induced snap-through of a buckled column with continuously distributed mass: A chaotic dynamics approach SO INTERNATIONAL JOURNAL OF NON-LINEAR MECHANICS LA English DT Article AB For a spatially-extended dynamical system we illustrate the use of a chaotic dynamics approach to obtain criteria on the occurrence of noise-induced escapes from a preferred region of phase space. Our system is a buckled column with continuous mass, subjected to a transverse continuously distributed load that varies randomly with time. We obtain a stochastic counterpart of the Melnikov necessary condition for chaos-and snap-through-derived by Holmes and Mardsen for the harmonic loading case. Our approach yields a lower bound for the probability that snap-through cannot occur during a specified time interval. In particular, for excitations with finite-tailed marginal distribution, a simple criterion is obtained that guarantees the non-occurrence of snap-through. Copyright (C) 1996 Published by Elsevier Science Ltd. C1 CRACOW PEDAGOG UNIV,INST PHYS,KRAKOW,POLAND. RP Franaszek, M (reprint author), NATL INST STAND & TECHNOL,BLDG & FIRE RES LAB,GAITHERSBURG,MD 20899, USA. NR 13 TC 8 Z9 8 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0020-7462 J9 INT J NONLINEAR MECH JI Int. J. Non-Linear Mech. PD NOV PY 1996 VL 31 IS 6 BP 861 EP 869 DI 10.1016/S0020-7462(96)00111-4 PG 9 WC Mechanics SC Mechanics GA WD724 UT WOS:A1996WD72400006 ER PT J AU Gillis, KA Moldover, MR AF Gillis, KA Moldover, MR TI Practical determination of gas densities from the speed of sound using square-well potentials SO INTERNATIONAL JOURNAL OF THERMOPHYSICS LA English DT Article DE acoustic virial coefficient; gas densities; equation of state; speed of sound; thermodynamic properties; virial coefficients ID THERMODYNAMIC PROPERTIES; THERMOPHYSICAL PROPERTIES; GASEOUS REFRIGERANTS; PRESSURES; METHANE; TEMPERATURES; APPARATUS; RANGE AB The relationships between the first three density virial coefficients (B, C, and D) and the first four acoustic virial coefficients (beta(a), gamma(a), delta(a), and epsilon(a)) are rederived and a published error relating D to delta(a) is corrected. We observe that even if the nth and higher-density virial coefficients of a hypothetical gas are identically zero, the nth and higher acoustic virial coefficients are not zero; they depend on the temperature derivatives of the 1st through (n-1)th density virial coefficients. Thus, two density virial coefficients may suffice for a fit to acoustic data with a cubic pressure dependence. These results are exploited by extending the pressure range of fits to previously published speed-of-sound data without either introducing additional parameters or degrading the fits. We deduce gas densities from fits to speed-of-sound data with acoustic virial coefficients having the temperature dependencies calculated from square-well potentials. The estimated densities differ from independent measurements by a few tenths of a percent in an important range of conditions. These estimates require no p-p-T data whatsoever. RP Gillis, KA (reprint author), NATL INST STAND & TECHNOL,PHYS & CHEM PROPERTIES DIV,CHEM SCI & TECHNOL LAB,GAITHERSBURG,MD 20899, USA. RI Moldover, Michael/E-6384-2013 NR 15 TC 41 Z9 43 U1 1 U2 4 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0195-928X J9 INT J THERMOPHYS JI Int. J. Thermophys. PD NOV PY 1996 VL 17 IS 6 BP 1305 EP 1324 DI 10.1007/BF01438672 PG 20 WC Thermodynamics; Chemistry, Physical; Mechanics; Physics, Applied SC Thermodynamics; Chemistry; Mechanics; Physics GA VN293 UT WOS:A1996VN29300007 ER PT J AU TillnerRoth, R AF TillnerRoth, R TI A nonlinear regression analysis for estimating low-temperature vapor pressures and enthalpies of vaporization applied to refrigerants SO INTERNATIONAL JOURNAL OF THERMOPHYSICS LA English DT Article DE ammonia; enthalpy of vaporization; extrapolation; R123; R124; R125; R134a; R143a; R152a; R32; refrigerants; triple point; vapor pressure ID THERMODYNAMIC PROPERTIES; 1,1,1,2-TETRAFLUOROETHANE R134A; STATE; DIFLUOROMETHANE; 1-CHLORO-1,2,2,2-TETRAFLUOROETHANE; PENTAFLUOROETHANE; EQUATION AB A new method is presented to extrapolate experimental vapor pressures down to the triple point. The method involves a nonlinear regression analysis based on the Clausius-Clapeyron equation and a simple relation for the enthalpy of vaporization. Triple-point pressures and vapor pressures up to 0.1-0.2 MPa are estimated for R125, R32, R143a, R134a, R152a, R123, R124, and ammonia; they generally agree with available experimental data within their uncertainty. Equations for the enthalpy of vaporization which describe this property fairly well at low temperatures are obtained as a byproduct. C1 UNIV HANNOVER,INST THERMODYNAM,D-30167 HANNOVER,GERMANY. RP TillnerRoth, R (reprint author), NATL INST STAND & TECHNOL,DIV THERMOPHYS,325 BROADWAY,BOULDER,CO 80303, USA. NR 39 TC 12 Z9 12 U1 0 U2 1 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0195-928X J9 INT J THERMOPHYS JI Int. J. Thermophys. PD NOV PY 1996 VL 17 IS 6 BP 1365 EP 1385 DI 10.1007/BF01438675 PG 21 WC Thermodynamics; Chemistry, Physical; Mechanics; Physics, Applied SC Thermodynamics; Chemistry; Mechanics; Physics GA VN293 UT WOS:A1996VN29300010 ER PT J AU Zhang, ZM Hanssen, LM Datla, RU Drew, HD AF Zhang, ZM Hanssen, LM Datla, RU Drew, HD TI An apparatus for infrared transmittance and reflectance measurements at cryogenic temperatures SO INTERNATIONAL JOURNAL OF THERMOPHYSICS LA English DT Article DE cryogenics; radiative properties; reflectance; transmittance ID REFRACTIVE-INDEXES; FT-IR; DETECTOR; SUPERCONDUCTORS; BOLOMETERS; SILICON AB A facility for measuring the optical properties of solid materials at cryogenic temperatures is bring developed at the National Institute of Standards and Technology. A cryostat that houses four bolometric detectors and a six-position sample holder was designed and built. The bolometers operate near 5 K, and the sample temperature can be varied from 6 to 100 K. The beam from a Fourier transform spectrometer is directed to the cryostat by reflective optical components. The measurable wavelengths extend from 1 mu m to 1 mm, with appropriate sources and beamsplitters in the spectrometer as well as as windows and detectors in the cryostat. Thr angle of incidence on the sample ranges from 7.5 to 60 degrees. The mechanical, electrical, and optical designs are described in this paper. Initial measurement results at wavelengths from 2 to 30 mu m and a sample temperature of 10 K are presented. C1 NATL INST STAND & TECHNOL,RADIOMETR PHYS DIV,GAITHERSBURG,MD 20899. UNIV MARYLAND,DEPT PHYS,COLLEGE PK,MD 20742. RP Zhang, ZM (reprint author), UNIV FLORIDA,DEPT MECH ENGN,GAINESVILLE,FL 32611, USA. NR 27 TC 7 Z9 7 U1 0 U2 4 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0195-928X J9 INT J THERMOPHYS JI Int. J. Thermophys. PD NOV PY 1996 VL 17 IS 6 BP 1441 EP 1454 DI 10.1007/BF01438678 PG 14 WC Thermodynamics; Chemistry, Physical; Mechanics; Physics, Applied SC Thermodynamics; Chemistry; Mechanics; Physics GA VN293 UT WOS:A1996VN29300013 ER PT J AU Cezairliyan, A Krishnan, S McClure, JL AF Cezairliyan, A Krishnan, S McClure, JL TI Simultaneous measurements of normal spectral emissivity by spectral radiometry and laser polarimetry at high temperatures in millisecond-resolution pulse-heating experiments: Application to molybdenum and tungsten SO INTERNATIONAL JOURNAL OF THERMOPHYSICS LA English DT Article DE high-speed measurements; high temperatures; laser polarimetry; molybdenum; normal spectral emissivity; pulse heating; pyrometry; radiation thermometry; spectral radiometry; tungsten ID OPTICAL-PROPERTIES; PHOTOPOLARIMETER; CALIBRATION AB Spectral radiometry and laser polarimetry are two independent techniques for the measurement of spectral emissivity of materials. In this paper, a high-speed system is described for the rapid measurement of normal spectral emissivity of a specimen based on the simultaneous utilization of the two techniques. One of the goals of this work was to ascertain the accuracy of the laser polarimetry technique in measurement of normal spectral emissivity at high temperatures. To accomplish this goal, the normal spectral emissivities, in the vicinity of 0.633 mu m, of molybdenum and tungsten were measured by the two techniques over the temperature range 2000 to 2800 K. The results obtained by the two techniques are in agreement within 1%. The total uncertainty (two-standard deviation level) in measurement of emissivity ty either spectral radiometry or laser polarimetry technique is estimated to be not more than +/- 2%. C1 CONTAINERLESS RES INC,EVANSTON,IL 60201. RP Cezairliyan, A (reprint author), NATL INST STAND & TECHNOL,DIV MET,GAITHERSBURG,MD 20899, USA. NR 15 TC 31 Z9 35 U1 0 U2 6 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0195-928X J9 INT J THERMOPHYS JI Int. J. Thermophys. PD NOV PY 1996 VL 17 IS 6 BP 1455 EP 1473 DI 10.1007/BF01438679 PG 19 WC Thermodynamics; Chemistry, Physical; Mechanics; Physics, Applied SC Thermodynamics; Chemistry; Mechanics; Physics GA VN293 UT WOS:A1996VN29300014 ER PT J AU Yang, SK Zhou, SS McMillan, LM Campana, KA AF Yang, SK Zhou, SS McMillan, LM Campana, KA TI Characteristics of the NOAA/NESDIS cloud retrieval algorithm using HIRS-MSU radiance measurements SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID RADIATION BUDGET; MODEL AB A cloud retrieval algorithm using NOAA/National Environmental Satellite, Data, and Information Service High-Resolution Infrared Radiation Sounder 2 Microwave Sounding Unit measurements from a polar-orbiting satellite, described in McMillin et al., uses multiple channel pairs with a two-pass procedure for enhancing accuracies. The current paper complements McMillin et al. in several ways. First it describes the characteristics of the channel pairs used in the algorithm while documenting the logic of the channel selection. It shows that the cloud-top heights and cloud fractions are dependent on the sensing channel pairs. The higher the altitude of the weighting function, the smaller the cloud fractions. Second, it adds an atmospheric attenuation correction and displays its effect on cloud-top heights. Without the attenuation correction, the cloud-top distributions are separated into two bands, possibly as a result of the distance between the heights of the weighting functions of the sensing channel pair. The attenuation correction effectively eliminates the gap, both by lowering the upper band and by elevating the lower band. The cloud fractions from this experimental operation are compared with Air Force Real-Time Nephanalysis for 3 months, and they reveal its strength in detecting low-level stratus. C1 RES & DATA SYST CORP,GREENBELT,MD. GEN SCI CORP,SAIC,LAUREL,MD. NOAA,NATL ENVIRONM SATELLITE DATA & INFORMAT SERV,OFF RES & APPLICAT,WASHINGTON,DC 20233. NOAA,NWS,NCEP,WASHINGTON,DC 20233. NR 12 TC 1 Z9 1 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD NOV PY 1996 VL 35 IS 11 BP 1980 EP 1990 DI 10.1175/1520-0450(1996)035<1980:COTNCR>2.0.CO;2 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VV053 UT WOS:A1996VV05300004 ER PT J AU Crone, LJ McMillin, LM Crosby, DS AF Crone, LJ McMillin, LM Crosby, DS TI Constrained regression in satellite meteorology SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article AB Least squares or regression techniques have been used for many problems in satellite meteorology. Because of the large number of variables and the linear dependence among these variables, colinearity causes significant problems in the application of standard regression techniques. In some of the applications there is prior knowledge about the values of the regression parameters. Since there are errors in the predictor variables as well as the predictand variables, the standard assumptions for ordinary least squares are not valid. In this paper the authors examine several techniques that have been developed to ameliorate the effects of colinearity or to make use of prior information. These include ridge regression, shrinkage estimators, rotated regression, and orthogonal regression. In order to illustrate the techniques and their properties, the authors apply them to two simple examples. These techniques are then applied to a real problem in satellite meteorology: that of estimating theoretical computed brightness temperatures from measured brightness temperatures. It is found that the-rotated and the shrinkage estimators make good use of the prior information and help solve the colinearity problem. Ordinary least squares, ridge regression, and orthogonal regression give unsatisfactory results. Theoretical results for the various techniques are given in an appendix. C1 NOAA,NATL ENVIRONM SATELLITE DATA & INFORMAT SERV,OFF RES & APPLICAT,SATELLITE RES LAB,WASHINGTON,DC 20233. AMERICAN UNIV,DEPT MATH & STAT,WASHINGTON,DC 20016. NR 14 TC 14 Z9 14 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD NOV PY 1996 VL 35 IS 11 BP 2023 EP 2035 DI 10.1175/1520-0450(1996)035<2023:CRISM>2.0.CO;2 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VV053 UT WOS:A1996VV05300007 ER PT J AU Ryzhkov, A Zrnic, D AF Ryzhkov, A Zrnic, D TI Assessment of rainfall measurement that uses specific differential phase SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID WEATHER RADAR; PRECIPITATION; POLARIZATION; SHAPE; HAIL; DROPS; SHIFT AB This paper examines some effects of drop size distribution and shape on the rainfall-rate estimates obtained from the specific differential phase. An algorithm that uses exclusively the specific differential phase is presented, and performance of this algorithm is examined by applying it to 15 storm events in Oklahoma that include heavy and light rainfalls. Radar-derived cumulative rainfall is compared to total rain measured by gauges in a dense gauge network in Oklahoma for each of the events. C1 NOAA,NATL SEVERE STORMS LAB,NORMAN,OK 73069. NR 22 TC 99 Z9 109 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD NOV PY 1996 VL 35 IS 11 BP 2080 EP 2090 DI 10.1175/1520-0450(1996)035<2080:AORMTU>2.0.CO;2 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VV053 UT WOS:A1996VV05300012 ER PT J AU Egelhoff, WF Chen, PJ Powell, CJ Stiles, MD McMichael, RD Lin, CL Sivertsen, JM Judy, JH Takano, K Berkowitz, AE AF Egelhoff, WF Chen, PJ Powell, CJ Stiles, MD McMichael, RD Lin, CL Sivertsen, JM Judy, JH Takano, K Berkowitz, AE TI Growth of giant magnetoresistance spin valves using Pb and Au as surfactants SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID TUNNELING-MICROSCOPY; EXCHANGE-ANISOTROPY; EPITAXIAL-GROWTH; FILM GROWTH; FE FILMS; SUPERLATTICES; CU(100); METALS; NIO; MULTILAYERS AB We have investigated the use of Pb and Au as surfactants in an attempt to achieve smoother and sharper interfaces in three types of giant magnetoresistance (GMR) spin valve multilayers: symmetric spin valves, bottom spin valves, and top spin valves. The coupling fields are reduced by a factor of 10 for symmetric and bottom spin valves and by a factor of 3 for top spin valves, presumably by suppressing roughness and interdiffusion at the Co/Cu/Co interfaces, when similar to 1 monolayer of Pb is deposited in the early stages of spin valve growth. The Pb has a strong tendency to float out or segregate to the surface during deposition of the spin valve leaving the GMR largely unaltered. Au is almost as effective as Pb, however the Au tends to be left behind in the spin valve, and the GMR is reduced slightly. Attempts to use Hg as a surfactant were unsuccessful. The coupling held increased, and the GMR decreased sharply. (C) 1996 American Institute of Physics. C1 UNIV MINNESOTA,CTR MICROMAGNET & INFORMAT TECHNOL,MINNEAPOLIS,MN 55455. UNIV MINNESOTA,DEPT CHEM ENGN & MAT SCI,MINNEAPOLIS,MN 55455. UNIV MINNESOTA,DEPT ELECT ENGN,MINNEAPOLIS,MN 55455. UNIV CALIF SAN DIEGO,DEPT PHYS,LA JOLLA,CA 92093. RP Egelhoff, WF (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. RI McMichael, Robert/J-8688-2012; Stiles, Mark/K-2426-2012; OI Stiles, Mark/0000-0001-8238-4156; McMichael, Robert/0000-0002-1372-664X NR 41 TC 56 Z9 59 U1 1 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD NOV 1 PY 1996 VL 80 IS 9 BP 5183 EP 5191 DI 10.1063/1.363460 PG 9 WC Physics, Applied SC Physics GA VN647 UT WOS:A1996VN64700056 ER PT J AU Wu, CC Dryer, M Smith, Z Wu, ST Lyu, LH AF Wu, CC Dryer, M Smith, Z Wu, ST Lyu, LH TI Recipe for predicting the IMF B-z polarity's change of direction following solar disturbances and at the onset of geomagnetic storms SO JOURNAL OF ATMOSPHERIC AND TERRESTRIAL PHYSICS LA English DT Article ID INTERPLANETARY MAGNETIC-FIELD; MAGNETOSPHERE; WIND AB A three-dimensional, time-dependent, MHD model of solar-disturbance-caused storms (Wu, 1993; Wu et al., 1996a) is used to predict the turning direction of the interplanetary magnetic field (IMF) at Earth. More explicitly, we examine the polarity of B-z caused by solar disturbances on the Sun. Three manifestations of solar disturbances, as studied by previous workers, are examined. Firstly, twenty-nine kilometric Type II events, associated (Cane, 1985) with geomagnetic storms, are studied within the context of our three-dimensional model. Then, an additional. eleven long-duration X-ray events (LDEs) with radio fluxes greater than 100 solar flux units were examined; these events were not associated with interplanetary Type II events but were also associated (Cane, 1985) with geomagnetic storms. Finally, in situ interplanetary phenomena that caused ten large (Dst < -100 nT, the intensification of the storm) geomagnetic storm episodes (Tsurutani et al., 1988) near solar maximum are also studied via the B-z predictions of our 3D MHD model. The accuracy of these B-z turning-direction-predictions is found to be as follows: (1) for the kilometric Type II events, the model's prediction was successful for 26 of the 29 events studied; (2) 10/11 for the LDE events; and (3) 7/9 for the major geomagnetic storm events. The overall prediction accuracy of these three independent data sets is 43/49. Thus, consideration of these three independent data sets strongly suggests that the recipe proposed by the basic 3D MHD model may be valid for a zero-th order prediction scheme. Copyright (C) 1996 Elsevier Science Ltd C1 NOAA,CTR SPACE ENVIRONM,BOULDER,CO 80303. UNIV COLORADO,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. UNIV ALABAMA,CTR SPACE PLASMA & AERONOM RES,HUNTSVILLE,AL 35899. UNIV ALABAMA,DEPT MECH ENGN,HUNTSVILLE,AL 35899. RP Wu, CC (reprint author), NATL CENT UNIV,INST SPACE SCI,CHUNGLI,TAIWAN. RI xue, yansheng/A-9712-2012 NR 21 TC 7 Z9 7 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0021-9169 J9 J ATMOS TERR PHYS JI J. Atmos. Terr. Phys. PD NOV PY 1996 VL 58 IS 15 BP 1805 EP 1814 DI 10.1016/0021-9169(96)00010-4 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UZ367 UT WOS:A1996UZ36700014 ER PT J AU Weber, LA Defibaugh, DR AF Weber, LA Defibaugh, DR TI Vapor pressures and PVT properties of the gas phase of 1,1,1-trifluoroethane SO JOURNAL OF CHEMICAL AND ENGINEERING DATA LA English DT Article ID 2ND VIRIAL-COEFFICIENTS AB A Burnett/isochoric PVT apparatus and a metal ebulliometer have been used to measure the gas-phase PVT surface and vapor pressures of 1,1,1-trifluoroethane (R143a). The PVT measurements spanned the temperature range 276 K to 373 K at pressures up to 6.6 MPa (densities to 6 mol . dm(-3)). A virial surface is given which represents the data up to a density of 3.5 mol . dm(-3). Formulations are given for the second and third virial coefficients. Vapor pressure measurements spanned the temperature range 236 K to 343 K. Thermodynamic calculations were used to extend the range down to a temperature of 180 K, and an equation is given which represents the vapor pressure curve from 180 K to the critical temperature. The temperature of the normal boiling point was found to be (225.90 +/- 0.01) K. Comparisons are made with other published results for R143a. RP Weber, LA (reprint author), NIST,CHEM SCI & TECHNOL LAB,PHYS & CHEM PROPERT DIV,GAITHERSBURG,MD 20899, USA. NR 18 TC 31 Z9 32 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0021-9568 J9 J CHEM ENG DATA JI J. Chem. Eng. Data PD NOV-DEC PY 1996 VL 41 IS 6 BP 1477 EP 1480 DI 10.1021/je9602071 PG 4 WC Thermodynamics; Chemistry, Multidisciplinary; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA VT766 UT WOS:A1996VT76600052 ER PT J AU Grabow, JU Andrews, AM Fraser, GT Irikura, KK Suenram, RD Lovas, FJ Lafferty, WJ Domenech, JL AF Grabow, JU Andrews, AM Fraser, GT Irikura, KK Suenram, RD Lovas, FJ Lafferty, WJ Domenech, JL TI Microwave spectrum, large-amplitude motions, and ab initio calculations for N2O5 SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID DINITROGEN PENTOXIDE; CROSS-SECTIONS; NITRIC-ACID; WATER DIMER; GAS-PHASE; ABSORPTION; MOMENT; SPECTROMETER; COMPLEXES; EXCHANGE AB The rotational spectrum of dinitrogen pentoxide (N2O5) has been investigated between 8 to 25 GHz at a rotational temperature of similar to 2.5 K using a pulsed-molecular-beam Fourier-transform microwave spectrometer. Two weak b-dipole spectra are observed for two internal-rotor states of the molecule, with each spectrum poorly characterized by an asymmetric-rotor Hamiltonian, The observation of only b-type transitions is consistent with the earlier electron-diffraction results of McClelland et al. [J. Am, Chem. Sec. 105, 3789 (1983)] which give a C-2 symmetry molecule with the b inertial axis coincident with the C-2 axis. Analysis of the N-14 nuclear hyperfine structure demonstrates that the two nitrogen nuclei occupy either structurally equivalent positions or are interchanging inequivalent structural positions via tunneling or internal rotation at a rate larger than similar to 1 MHz. For the two internal rotor states, rotational levels with K-a + K-c even have I-N = 0, 2, while levels with K-a + K-c odd have I-N = 1, where I-N is the resultant nitrogen nuclear spin, This observation establishes that the equilibrium configuration of the molecule has a twofold axis of symmetry. Guided by ab initio and dynamical calculations which show a planar configuration is energetically unfavorable, we assign the spectrum to the symmetric and antisymmetric tunneling states of a C-2 symmetry N2O5 with internal rotation tunneling of the two NO2 groups via a geared rotation about their respective C-2 axes. Because of the Bose-Einstein statistics of the spin-zero oxygen nuclei, which require that the rotational-vibrational-tunneling wave functions be symmetric for interchange of the O nuclei, only four of the ten vibrational-rotational-tunneling states of the molecule have nonzero statistical weights. Model dynamical calculations suggest that the internal-rotation potential is significantly more isotropic than implied by the electron-diffraction analysis. (C) 1996 American Institute of Physics. C1 CSIC, INST ESTRUCTURA MAT, E-28006 MADRID, SPAIN. NATL INST STAND & TECHNOL, DIV OPT TECHNOL, GAITHERSBURG, MD 20899 USA. INST DEF ANAL, DIV SCI & TECHNOL, ALEXANDRIA, VA 22311 USA. RI Domenech, Jose/F-5561-2013; Irikura, Karl/A-4266-2009 OI Domenech, Jose/0000-0001-8629-2566; Irikura, Karl/0000-0001-7515-6761 NR 41 TC 11 Z9 11 U1 3 U2 9 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-9606 EI 1089-7690 J9 J CHEM PHYS JI J. Chem. Phys. PD NOV 1 PY 1996 VL 105 IS 17 BP 7249 EP 7262 DI 10.1063/1.472586 PG 14 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VP288 UT WOS:A1996VP28800001 ER PT J AU Lindberg, C Broccoli, AJ AF Lindberg, C Broccoli, AJ TI Representation of topography in spectral climate models and its effect on simulated precipitation SO JOURNAL OF CLIMATE LA English DT Article ID GLOBAL PRECIPITATION AB Spectral climate models are distinguished by their representation of variables as finite sums of spherical harmonics, with coefficients computed by an orthogonal projection of the Variables onto the spherical harmonics. Representing the surface elevation in this manner results in its contamination by Gibbs-like truncation artifacts, which appear as spurious valleys and mountain chains in the topography. These ''Gibbs ripples'' are present in the surface topographies of spectral climate models from a number of research institutions. Integrations of the Geophysical Fluid Dynamics Laboratory (GFDL) climate model over a range of horizontal resolutions indicate that the Gibbs ripples lead to spurious, small-scale extrema in the spatial distribution of precipitation. This ''cellular precipitation pathology'' becomes more pronounced with increasing horizontal resolution, causing a deterioration in the fidelity of simulated precipitation in higher resolution models. A method is described for reducing the Gibbs ripples that occur when making an incomplete spherical harmonic expansion of the topography. The new spherical harmonic representations of topography are formed by fitting a nonuniform spherical smoothing spline to geodetic data and found by solving a fixed-point problem. This regularization technique results in less distortion of features such as mountain height and continental boundaries than previous smoothing methods. These new expansions of the topography, when used as a lower boundary surface in the GFDL climate model, substantially diminish the cellular precipitation pathology and produce markedly more realistic simulations of precipitation. These developments make the prospect of using higher resolution spectral models for studies of regional hydrologic climate more attractive. C1 PRINCETON UNIV,NOAA,GEOPHYS FLUID DYNAM LAB,PRINCETON,NJ 08542. PRINCETON UNIV,PROGRAM ATMOSPHER & OCEAN SCI,PRINCETON,NJ 08544. RI Broccoli, Anthony/D-9186-2014 OI Broccoli, Anthony/0000-0003-2619-1434 NR 34 TC 20 Z9 20 U1 0 U2 8 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD NOV PY 1996 VL 9 IS 11 BP 2641 EP 2659 DI 10.1175/1520-0442(1996)009<2641:ROTISC>2.0.CO;2 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VX838 UT WOS:A1996VX83800001 ER PT J AU Barnston, AG Smith, TM AF Barnston, AG Smith, TM TI Specification and prediction of global surface temperature and precipitation from global SST using CCA SO JOURNAL OF CLIMATE LA English DT Article ID NINO-SOUTHERN OSCILLATION; CANONICAL CORRELATION-ANALYSIS; NORTHERN-HEMISPHERE; RAINFALL VARIABILITY; GEOPOTENTIAL HEIGHT; SEASONAL FORECASTS; EQUATORIAL PACIFIC; STATISTICAL-MODELS; CLIMATE ANOMALIES; AFRICAN RAINFALL AB A reconstructed sea surface temperature (SST) dataset is used to examine relationships between SST and seasonal mean surface temperature (T) and total precipitation (P) over most of the global continents for the 1950-92 period. Both specification (i.e., simultaneous) and predictive relations are studied. Canonical correlation analysis (CCA) is used to describe the relationships and to provide information aiding in physical interpretation. A sequence of four consecutive 3-month periods of global SST anomalies is related to T and P anomalies during the fourth period for the specification analyses, and to 3-month periods ranging from one to four seasons later for the predictive analyses. Dynamical specifications of the National Centers for Environmental Prediction (NCEP) atmospheric model, using observed SST anomalies as boundary conditions, are also examined for confirmation of and comparison with the statistical specification relationships suggested by the CCA. Specification and predictive cross-validated skill is modest except for certain regions and/or times of the year having correlations of 0.5 and greater. Seasonal T is generally specified/predicted with greater skill than P. Some regions have seasonality in their specificability/predictability, where skill varies more strongly as a function of the target season than lead time for T, P, or both. In these cases, such as Sahel African rainfall in northern summer or northeastern Australian rainfall in May through July, the skill of specification is not substantially higher than the skill of shea or even moderately long lead prediction. Specifications and predictions are skillful in areas affected by the ENSO, including the tropical Pacific islands for all seasons, and during specific seasons in northern and eastern Australia, and parts of Africa and North and South America. Skill is lowest in Europe and midlatitude Asia where ENSO's direct influence is lacking. However, non-ENSO predictive skill sources also contribute substantially to final skill; these exist both in regions strongly and minimally influenced by ENSO. The most important of these is an interdecadal trend from the 1950s to the 1980s-90s defined by a warming in the Indian and South Atlantic Oceans paralleling a cooling in the North Pacific and Atlantic basins. Another controlling SST dipole with a less obvious trend includes mainly the tropical SST of all three ocean basins versus the extratropical (especially Northern Hemisphere) SST. Still other, more localized, SST patterns are suggested as critical. Some of the regions that show modest but usable seasonal predictive potential have no prior specificative or predictive history because they are not directly influenced by ENSO and/or have marginal data quality or density. This is encouraging, since the statistical skill realized here should be reproducible, and hopefully surpassable, using dynamical models. RP Barnston, AG (reprint author), NOAA,NATL WEATHER SERV,CLIMATE PREDICT CTR,WNP51 WWB RM 604,WASHINGTON,DC 20233, USA. RI Smith, Thomas M./F-5626-2010 OI Smith, Thomas M./0000-0001-7469-7849 NR 70 TC 113 Z9 124 U1 0 U2 5 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD NOV PY 1996 VL 9 IS 11 BP 2660 EP 2697 DI 10.1175/1520-0442(1996)009<2660:SAPOGS>2.0.CO;2 PG 38 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VX838 UT WOS:A1996VX83800002 ER PT J AU Oort, AH Yienger, JJ AF Oort, AH Yienger, JJ TI Observed interannual variability in the Hadley circulation and its connection to ENSO SO JOURNAL OF CLIMATE LA English DT Article ID SEA-SURFACE TEMPERATURE; SOUTHERN OSCILLATION; ATMOSPHERE; MOMENTUM; BALANCE; OCEAN AB Based on a 26-yr set of daily global upper-air wind data for the period January 1964-December 1989, the interannual variability in the strength of the tropical Hadrey cells is investigated. Although several measures of the intensity of the zonal-mean cells are discussed, the main focus is on the maximum in the streamfunction ia the northern and southern Tropics. The streamfunction was computed from observed monthly mean latitude versus pressure cross sections of the zonal-mean meridional wind component. Significant seasonal Variations are found in the strength, latitude, and height of the maximum streamfunction for both Hadley cells. Significant correlations are also observed between the Hadley cells and the El Nino-Southern Oscillation phenomenon. During the extreme seasons, only one ''winter'' Hadley cell dominates the Tropics, with the rising branch in the summer hemisphere and the sinking branch in the winter hemisphere. Superimposed an this ''normal'' one-cell winter Hadley circulation in the Tropics are two strengthened direct (i.e., energy releasing) Hadrey cells found during episodes of warm sea surface temperature anomalies in the eastern equatorial Pacific (EI Nino) and weakened Hadley cells during episodes of cold anomalies. The anomalies in the strength of the Hadley cells are strongly and inversely correlated with the anomalies in the strength of the Walker oscillation. C1 PRINCETON UNIV,ATMOSPHER & OCEAN SCI PROGRAM,PRINCETON,NJ 08544. RP Oort, AH (reprint author), PRINCETON UNIV,NOAA,GEOPHYS FLUID DYNAM LAB,FORESTAL CAMPUS,US ROUTE 1,POB 308,PRINCETON,NJ 08542, USA. NR 20 TC 209 Z9 221 U1 4 U2 22 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD NOV PY 1996 VL 9 IS 11 BP 2751 EP 2767 DI 10.1175/1520-0442(1996)009<2751:OIVITH>2.0.CO;2 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VX838 UT WOS:A1996VX83800006 ER PT J AU Chen, CT Ramaswamy, V AF Chen, CT Ramaswamy, V TI Sensitivity of simulated global climate to perturbations in low cloud microphysical properties .2. Spatially localized perturbations SO JOURNAL OF CLIMATE LA English DT Article ID GENERAL-CIRCULATION MODEL; ANTHROPOGENIC AEROSOLS; FEEDBACK PROCESSES; ALBEDO; PARAMETERIZATION; PHYTOPLANKTON; POLLUTION AB The sensitivity of the global climate to spatially localized (20 degrees-70 degrees N) perturbations in the microphysical properties of low clouds is investigated using a general circulation model coupled to a mixed layer ocean with fixed cloud distributions. By comparing with earlier experiments involving globally uniform perturbations, insights are obtained into the climate responses to spatially inhomogeneous radiative forcings, such as that due to the contrast in the effective drop radius of land and ocean clouds and the anthropogenic sulfate aerosol-induced alteration of cloud albedo. The main findings of this study are as follows: 1) The model's climate sensitivity (ratio of global-mean surface temperature response to the global-mean radiative forcing) is virtually independent of the distribution and magnitude of forcing. 2) Although the total feedback is very similar in the different experiments, the strengths of the individual feedback mechanisms (water vapor, albedo, lapse rate) are dissimilar. 3) For the localized perturbations, the climate response is essentially confined to the hemisphere in which the forcing occurs, offing to a poor interhemispheric energy exchange. 4) In spite of no forcing in the Southern Hemisphere in the localized experiments, there is a weak ''remote'' temperature response there. 5) For both global and localized perturbations, the temperature response in the tropical upper troposphere is larger than in the lower troposphere due to moist convective processes; in the localized experiments, while there is a strong vertical gradient in the temperature change at the Northern Hemisphere mid and high latitudes. the temperature change throughout the lower and midtroposphere of the Southern Hemisphere is uniform. 6) The localized experiments induce notable changes in the mean meridional circulation and precipitation near the equator, which are not obtained for the global perturbation cases. 7) The pattern of temperature response of the land and ocean areas in the Northern Hemisphere midlatitudes depends on whether the forcing occurs over both types of surfaces or over land only; the results suggest that the well-known contrast in drop radii between continental and maritime clouds exerts a significant influence on the surface temperature distribution within the zone and on the manner in which the surface energy balance is maintained. C1 PRINCETON UNIV,NOAA,GEOPHYS FLUID DYNAM LAB,PRINCETON,NJ 08542. PRINCETON UNIV,ATMOSPHER & OCEAN SCI PROGRAM,PRINCETON,NJ 08544. NR 31 TC 13 Z9 13 U1 0 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD NOV PY 1996 VL 9 IS 11 BP 2788 EP 2801 DI 10.1175/1520-0442(1996)009<2788:SOSGCT>2.0.CO;2 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VX838 UT WOS:A1996VX83800009 ER PT J AU Gallo, KP Easterling, DR Peterson, TC AF Gallo, KP Easterling, DR Peterson, TC TI The influence of land use land cover on climatological values of the diurnal temperature range SO JOURNAL OF CLIMATE LA English DT Article ID URBAN AB The diurnal temperature range (DTR) at weather observation stations that make up the U.S. Historical Climatology Network was evaluated with respect to the predominant land use/land cover associated with the stations within three radii intervals (100, 1000, and 10 000 m) of the stations. Those stations that were associated with predominantly rural land use/land cover (LULC) usually displayed the greatest observed DTR, whereas those associated with urban related land use or land cover displayed the least observed DTR. The results of this study suggest that significant differences' in the climatological DTR were observed and could be attributed to the predominant LULC associated with the observation stations. The results also suggest that changes in the predominant LULC conditions, within as great as a 1O 000 m radius of an observation station, could significantly influence the climatological DTR. Future changes in the predominant LULC associated with observation sites should be monitored similar to the current practice of monitoring changes in instruments or time of observation at the observations sites. C1 NOAA,NATL ENVIRONM SATELLITE DATA & INFORMAT SERV,OFF RES APPL,WASHINGTON,DC 20233. RP Gallo, KP (reprint author), NATL CLIMAT CTR,GLOBAL CLIMATE LAB,151 PATTON AVE,ASHEVILLE,NC 28801, USA. RI Gallo, Kevin P./F-5588-2010 NR 10 TC 99 Z9 113 U1 3 U2 18 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD NOV PY 1996 VL 9 IS 11 BP 2941 EP 2944 DI 10.1175/1520-0442(1996)009<2941:TIOLUC>2.0.CO;2 PG 4 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VX838 UT WOS:A1996VX83800019 ER PT J AU Steiner, B Levine, LE Brown, M Larson, D AF Steiner, B Levine, LE Brown, M Larson, D TI Residual disorder in low pressure, low thermal gradient liquid encapsulated Czochralski gallium arsenide observed in high resolution synchrotron diffraction imaging SO JOURNAL OF CRYSTAL GROWTH LA English DT Article ID DISLOCATION FORMATION; GAAS; RADIATION; GROWTH; TOPOGRAPHY; CRYSTALS AB High resolution synchrotron X-radiation diffraction images of low thermal gradient, low pressure, liquid encapsulated Czochralski (LEG) silicon-doped gallium arsenide display a degree of crystalline order that is far higher than that found in undoped conventional LEC material. No distinct Volume irregularity is observed in one crystal where it is unstrained. Only a set of surface-treatment-related dislocations is prominent in a second. A third crystal exhibits two distinct sets of quasi periodic dislocations, which have been analyzed in detail. The results support a model previously proposed for the evolution of disorder in gallium arsenide and suggest the role that silicon plays in its control. C1 GRUMMAN CORP,BETHPAGE,NY 11714. RP Steiner, B (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 17 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0248 J9 J CRYST GROWTH JI J. Cryst. Growth PD NOV PY 1996 VL 169 IS 1 BP 1 EP 12 DI 10.1016/0022-0248(96)00152-2 PG 12 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA VQ726 UT WOS:A1996VQ72600001 ER PT J AU Niaura, G Gaigalas, AK Vilker, VL AF Niaura, G Gaigalas, AK Vilker, VL TI Non-resonant SERS study of the adsorption of cytochrome c on a silver electrode SO JOURNAL OF ELECTROANALYTICAL CHEMISTRY LA English DT Article DE SERS; cytochrome c; silver electrode; 632.8 nm excitation ID ENHANCED RAMAN-SPECTROSCOPY; DIRECT ELECTROCHEMISTRY; HEME PROTEINS; SURFACE; SCATTERING; REDUCTION; SPECTRA; AG; INTENSITIES; HEMOGLOBIN AB Non-resonant surface-enhanced Raman spectroscopy (SERS) using 632.8 nm excitation was applied to the study of adsorption and redox changes of cytochrome c (cyt c) on a silver electrode. The bands from specifically adsorbed phosphate anions, heme group, and aromatic residues have been assigned in SER spectra. An electrode deactivation procedure was devised to enhance the signal of cyt c relative to that from adsorbed phosphate anions. The intensity of the B-1g modes has been found to be preferentially enhanced via the pre-resonance enhancement mechanism. The redox marker band nu(4)A(1g), not observed in solution cyt c Raman spectra with 632.8 nm excitation, was surface enhanced and seen in SERS at 1370 cm(-1) for cyt c(3+) and 1364cm(-1) for cyt c(2+). The nu(15)B(1g) mode at 742 cm(-1) (cyt c(2+)) was the most intense SERS peak and could serve as an indicator for the redox state of the adsorbed protein. The heme associated propionate modes have been found to be preferentially enhanced in SER spectra compared with solution, indicating the close proximity of the propionate group relative to the surface. Irreversible changes in SER spectra have been observed at potentials more negative than -0.7 V. The diminished intensity of the heme modes, and the appearance of bands associated with tyrosine and phenylalanine residues, as well as amide III mode, have been explained in terms of a new conformational state where the protein is partially unfolded. RP Niaura, G (reprint author), NATL INST STAND & TECHNOL,DIV BIOTECHNOL,GAITHERSBURG,MD 20899, USA. NR 43 TC 28 Z9 28 U1 0 U2 13 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0022-0728 J9 J ELECTROANAL CHEM JI J. Electroanal. Chem. PD NOV 1 PY 1996 VL 416 IS 1-2 BP 167 EP 178 DI 10.1016/S0022-0728(96)04727-4 PG 12 WC Chemistry, Analytical; Electrochemistry SC Chemistry; Electrochemistry GA VT937 UT WOS:A1996VT93700021 ER PT J AU Gautam, AB Strand, I Kirkley, J AF Gautam, AB Strand, I Kirkley, J TI Leisure/labor tradeoffs: The backward-bending labor supply in fisheries SO JOURNAL OF ENVIRONMENTAL ECONOMICS AND MANAGEMENT LA English DT Article ID UNCERTAINTY; BEHAVIOR AB Economists have understood that the open-access nature of fishing grounds can cause the long-run fishery supply to bend backward. There is also increasing speculation that fishermen respond to falling output price either by increasing or decreasing effort, depending on the circumstances. This suggests a short-run backward-bending supply of fishing labor. A dynamic, utility-theoretic model of fishermen's behavior is developed to address this possibility. The model highlights both contemporaneous and intertemporal trade-offs between labor and leisure. The model is tested and the results indicate that the short-run labor supply in fisheries may exhibit backward-bending properties. In addition, changes in current prices may trigger changes in expectations of future prices, causing potentially greater counterintuitive behavior. These results challenge many traditional regulatory strategies (e.g., output taxes) that address problems of open access. (C) 1996 Academic Press, Inc. C1 UNIV MARYLAND,DEPT AGR & RESOURCE ECON,COLLEGE PK,MD 20742. VIRGINIA INST MARINE SCI,GLOUCESTER POINT,VA 23062. RP Gautam, AB (reprint author), NATL MARINE FISHERIES SERV,SILVER SPRING,MD 20910, USA. NR 20 TC 4 Z9 4 U1 1 U2 6 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0095-0696 J9 J ENVIRON ECON MANAG JI J.Environ.Econ.Manage. PD NOV PY 1996 VL 31 IS 3 BP 352 EP 367 DI 10.1006/jeem.1996.0049 PG 16 WC Business; Economics; Environmental Studies SC Business & Economics; Environmental Sciences & Ecology GA VV316 UT WOS:A1996VV31600006 ER PT J AU Gitschlag, GR AF Gitschlag, GR TI Migration and diving behavior of Kemp's ridley (Garman) sea turtles along the US southeastern Atlantic coast SO JOURNAL OF EXPERIMENTAL MARINE BIOLOGY AND ECOLOGY LA English DT Article DE diving behavior; Kemp's ridley; migration; sea turtle ID STREAM FRONTAL EDDY; CARETTA-CARETTA; MOVEMENTS; VICINITY; FLORIDA; SHELF AB Three Kemp's ridley (Lepidochelys kempii, Garman) sea turtles were tracked with satellite and radio/sonic telemetry from release points along the Georgia coast beginning in October 1991. The movement demonstrated by these turtles was consistent with seasonal, coastal migration. Radio-tagged juveniles travelled south from Georgia to Florida a distance of 120 and 202 km during 41 and 29 days of monitoring, respectively. Submergence duration was significantly longer at night than during the day for one of two juvenile turtles. A nesting-sized Kemp's ridley tracked via satellite telemetry from October 1991 to July 1992 made longer dives than the radio tagged juveniles, but the percent submergence time was very similar, 94% and 95%, respectively. Seasonal and day-night differences in average submergence duration were significant for the satellite tracked turtle, and longer dives occurred at night throughout all seasons. In spring, average submergence duration was shorter. From mid-November to mid-March the primary overwintering grounds of the nesting-sized ridley sea turtle were within approximately 40 km of the Atlantic coast between Cape Canaveral and Stuart, Florida. During late spring and early summer, coastal South Carolina was the preferred habitat of this individual. RP Gitschlag, GR (reprint author), NATL MARINE FISHERIES SERV, SE FISHERIES CTR, GALVESTON LAB, 4700 AVE U, GALVESTON, TX 77551 USA. NR 47 TC 18 Z9 23 U1 1 U2 14 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0981 J9 J EXP MAR BIOL ECOL JI J. Exp. Mar. Biol. Ecol. PD NOV 1 PY 1996 VL 205 IS 1-2 BP 115 EP 135 DI 10.1016/S0022-0981(96)02602-0 PG 21 WC Ecology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA VU573 UT WOS:A1996VU57300008 ER PT J AU Riley, P Gosling, JT Weiss, LA Pizzo, VJ AF Riley, P Gosling, JT Weiss, LA Pizzo, VJ TI The tilts of corotating interaction regions at midheliographic latitudes SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID STREAM INTERACTION REGIONS; HELIOSPHERIC CURRENT SHEET; RANKINE-HUGONIOT PROBLEM; QUASI-STEADY DYNAMICS; DISTANT SOLAR-WIND; OUTER HELIOSPHERE; ECLIPTIC-PLANE; PLASMA-FLOW; ULYSSES; MODULATION AB Previous analysis of midlatitude corotating interaction regions (CIRs) observed by Ulysses in the southern heliosphere has revealed that the flow downstream of the forward (F) shock (or wave) on the leading edge of a CIR generally turns northward and into the direction of planetary motion (westward), while the flow downstream of the reverse (R) shock (or wave) on the trailing edge generally turns southward and eastward. These systematic flow deflections are a natural consequence of large-scale pressure gradients associated with the CIRs and indicate that the F shocks tend to propagate toward and across the equator with increasing heliocentric distance, while the R shocks tend to propagate toward the pole. Numerical simulations indicate that these effects are a natural consequence of the tilt of the solar magnetic-dipole axis relative to the solar rotation axis. The present work utilizes a variety of techniques to analyze the flow deflections observed within midlatitude CIRs from which we can infer the overall orientations of the CIRs and the speeds and directions of propagation of the waves. Notable results include the following: (1) On the whole, F shocks do propagate equatorward and westward, and R shocks propagate poleward and eastward; (2) shock parameters show a modulation in amplitude, peaking at latitudes roughly equivalent to the inferred dipole-tilt angle; (3) R shocks tend to propagate faster (in the upstream solar wind frame) than their counterpart F shocks; and (4) meridional deflections tend to be larger than azimuth deflections for both F and R shocks. While it is reassuring that most of the CIRs analyzed fit the paradigm, there are a significant number of anomalies. We discuss several mechanisms which could, in principle, cause these apparent contradictions. For example, the present analysis necessarily emphasizes the local structure at the shock front. The agreement improves significantly, however, when the large-scale flow deflections throughout the CIR are taken into account. C1 NOAA,SPACE ENVIRONM LAB,BOULDER,CO 80303. UNIV ARIZONA,LUNAR & PLANETARY LAB,TUCSON,AZ 85721. NR 26 TC 35 Z9 35 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD NOV 1 PY 1996 VL 101 IS A11 BP 24349 EP 24357 DI 10.1029/96JA02447 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VQ495 UT WOS:A1996VQ49500003 ER PT J AU Kahler, SW Kunches, JM Smith, DF AF Kahler, SW Kunches, JM Smith, DF TI Role of current sheets in the modulation of solar energetic particle events SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID CORONAL MASS EJECTIONS; HELIOSPHERIC CURRENT SHEET; MEAN IONIC CHARGE; INTERPLANETARY SHOCKS; SMM OBSERVATIONS; SECTOR STRUCTURE; PROTON EVENTS; FIELD; ABUNDANCES; FLARES AB Recent results have clarified the way in which solar energetic (E > 10 MeV) particles (SEPs) are produced in the solar corona and interplanetary medium. The principal result is that most SEPs in large events are accelerated on open field Lines by large-scale shocks driven by coronal mass ejections (CMEs). However, the large range of timescales for different SEP events associated with solar source regions at comparable longitudes suggests that the shocks are somehow strongly modulated near the Sun. We investigate the possibility that the coronal streamer belt and current sheet provides a barrier for shock propagation and associated SEP acceleration, as suggested in several recent studies. We use solar flares as proxies for CMEs and plot on the Stanford source surface maps the positions of flares associated with large (F > 10 p/cm(2)sr s at E > 10 MeV) SEP events observed at the Earth. The basic question is whether SEPs are preferentially observed when the Earth occupies the same magnetic sector as the associated solar flare. We find that onset times, risetimes, and peak fluxes are essentially the same for SEP events with flares in the same sector as for those in the opposite polarity sectors. This suggests that the streamer structure has no detectible effect on the development of the shock and CME driver. We discuss several alternative possibilities to explain the large variation in SEP event timescales. C1 NOAA,SPACE ENVIRONM CTR,BOULDER,CO 80303. UNIV COLORADO,DEPT ASTROPHYS PLANETARY & ATMOSPHER SCI,BOULDER,CO 80309. RP Kahler, SW (reprint author), USAF,PHILLIPS LAB,GPSG,BEDFORD,MA 01731, USA. NR 64 TC 7 Z9 7 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD NOV 1 PY 1996 VL 101 IS A11 BP 24383 EP 24391 DI 10.1029/96JA02446 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VQ495 UT WOS:A1996VQ49500006 ER PT J AU Hale, PD Wang, CM Park, R Lau, WY AF Hale, PD Wang, CM Park, R Lau, WY TI A transfer standard for measuring photoreceiver frequency response SO JOURNAL OF LIGHTWAVE TECHNOLOGY LA English DT Article ID NONPARAMETRIC REGRESSION; NIST; NPL AB We have developed a photoreceiver frequency response transfer standard which can be used to measure the optical modulation transfer function of a modulated optical source, It combines a photodiode with an RF power sensor or an amplified receiver with an RF power sensor. It is calibrated with an expanded uncertainty of 0.06 dB (coverage factor = 2) using a heterodyne technique at 1.319 mu m We present a theory which allows use of the transfer standard with arbitrary source modulation depth. The calibration is transferred to a SDH/SONET test equipment manufacturer giving a final uncertainty well below the 0.3 dB uncertainty specified by ITU-TS (formerly CCITT) recommendation G.957. The transfer standard may have other applications including calibration of CATV test equipment, lightwave component analyzers, and lightwave spectrum analyzers. C1 NATL INST STAND & TECHNOL,DIV STAT ENGN,BOULDER,CO 80303. HEWLETT PACKARD CORP,LIGHTWAVE OPERAT,SANTA ROSA,CA 95403. RP Hale, PD (reprint author), NATL INST STAND & TECHNOL,DIV OPTOELECT,325 BROADWAY,BOULDER,CO 80303, USA. RI Hale, Paul/B-1737-2013 NR 13 TC 10 Z9 10 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0733-8724 J9 J LIGHTWAVE TECHNOL JI J. Lightwave Technol. PD NOV PY 1996 VL 14 IS 11 BP 2457 EP 2466 DI 10.1109/50.548142 PG 10 WC Engineering, Electrical & Electronic; Optics; Telecommunications SC Engineering; Optics; Telecommunications GA VT423 UT WOS:A1996VT42300002 ER PT J AU Rose, AH Ren, ZB Day, GW AF Rose, AH Ren, ZB Day, GW TI Twisting and annealing optical fiber for current sensors SO JOURNAL OF LIGHTWAVE TECHNOLOGY LA English DT Article ID POLARIZATION MODE-DISPERSION; TEMPERATURE-DEPENDENCE; LINEAR BIREFRINGENCE; VERDET CONSTANT; STRESS AB We demonstrate that twisting a fiber a few turns per meter before it is annealed largely eliminates the residual linear birefringence. This dramatically improves the yield of annealed toils used for current sensing and makes it possible to use fibers that previously had large residual linear birefringence. Twisting the fiber is effective because the residual birefringence, associated with core ellipticity, is reduced to near zero by twisting. A theoretical model of the twisted and annealed fiber current sensor is compared to experimental data, We also show good temperature stability for a sensor made with this new technique. RP Rose, AH (reprint author), NATL INST STAND & TECHNOL,325 BROADWAY,BOULDER,CO 80303, USA. NR 39 TC 40 Z9 44 U1 1 U2 8 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0733-8724 J9 J LIGHTWAVE TECHNOL JI J. Lightwave Technol. PD NOV PY 1996 VL 14 IS 11 BP 2492 EP 2498 DI 10.1109/50.548146 PG 7 WC Engineering, Electrical & Electronic; Optics; Telecommunications SC Engineering; Optics; Telecommunications GA VT423 UT WOS:A1996VT42300006 ER PT J AU Paulik, SW Zimmerman, MH Faber, KT Fuller, ER AF Paulik, SW Zimmerman, MH Faber, KT Fuller, ER TI Residual stress in ceramics with large thermal expansion anisotropy SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID GRAIN-SIZE DEPENDENCE; BRITTLE SOLIDS; ALUMINUM TITANATE; MICROCRACKING; CRACKING; MICROFRACTURE; AL2O3 AB Residual stress was measured in sintered and heat-treated Fe2TiO5 samples with various grain sizes. The influence of texturing was assessed by comparing the residual stress states of samples having randomly oriented grains and highly oriented grains produced through magnetically assisted processing. The residual stress was measured with x-ray diffraction using CrKalpha radiation. Due to the significant texture and the consequential oscillations in the d(phi psi) vs sin(2) psi data, the residual stress was calculated using the Marion-Cohen method. Textured samples showed significantly lower residual stresses except when spontaneous microcracking accompanied grain growth in the randomly oriented systems. Elastic modulus measurements showed a direct correlation between the decrease in residual stress and the microcrack density. C1 NIST,GAITHERSBURG,MD 20899. RP Paulik, SW (reprint author), NORTHWESTERN UNIV,ROBERT R MCCORMICK SCH ENGN & APPL SCI,DEPT MAT SCI & ENGN,EVANSTON,IL 60208, USA. RI Faber, Katherine/B-6741-2009 NR 39 TC 16 Z9 16 U1 1 U2 5 PU MATERIALS RESEARCH SOCIETY PI PITTSBURGH PA 9800 MC KNIGHT ROAD SUITE 327, PITTSBURGH, PA 15237 SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD NOV PY 1996 VL 11 IS 11 BP 2795 EP 2803 DI 10.1557/JMR.1996.0354 PG 9 WC Materials Science, Multidisciplinary SC Materials Science GA VT784 UT WOS:A1996VT78400019 ER PT J AU vanHeerden, D Zolotoyabko, E Shechtman, D AF vanHeerden, D Zolotoyabko, E Shechtman, D TI Microstructure and strain in electrodeposited Cn/Ni multilayers SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID X-RAY-DIFFRACTION; NI THIN-FILMS; MECHANICAL-PROPERTIES; MODULATED ALLOYS; SUPERLATTICES; BEHAVIOR; CRYSTALS; FOILS AB Electrodeposited Cu/Ni multilayers with different modulation lengths Lambda = 4-18 nm were examined by means of x-ray diffraction and transmission electron microscopy. Preferred orientations of [111], [110], and [001]-types, as determined from relative x-ray diffraction peak intensities, were seen in the multilayers. By means of computer simulations of the measured x-ray diffraction spectra, several parameters of the multilayers, such as Lambda-values and fluctuations Delta Lambda, as well as lattice strain, were determined. Multilayers having large Lambda were found to be fully relaxed due to interfacial dislocation formation. In short Lambda [001]-texture multilayers partial strain relaxation occurs, probably due to the incorporation of Cu into the Ni layers. Both of the processes lead to the diffuse Cu/Ni interfaces. Short wavelength multilayers with a [111]-preferred orientation were almost fully strained. The importance of the [111]-texture in the improvement of mechanical strength of Cu/Ni multilayers resulting from its enhanced ability for stain accommodation is discussed. C1 TECHNION ISRAEL INST TECHNOL,DEPT MAT ENGN,IL-32000 HAIFA,ISRAEL. RP vanHeerden, D (reprint author), NIST,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899, USA. NR 27 TC 16 Z9 16 U1 0 U2 3 PU MATERIALS RESEARCH SOCIETY PI PITTSBURGH PA 9800 MC KNIGHT ROAD SUITE 327, PITTSBURGH, PA 15237 SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD NOV PY 1996 VL 11 IS 11 BP 2825 EP 2833 DI 10.1557/JMR.1996.0357 PG 9 WC Materials Science, Multidisciplinary SC Materials Science GA VT784 UT WOS:A1996VT78400022 ER PT J AU Pliva, J Pine, AS Civis, S AF Pliva, J Pine, AS Civis, S TI The perpendicular C-H stretching band nu(g)/nu(13) and the torsional potential of dimethylacetylene SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID INTERNAL-ROTATION; INFRARED-SPECTRA; NU-3-BAND AB The perpendicular band of the fourfold degenerate C-H stretching vibration of dimethylacetylene (2-butyne) occurring in the region 2955-3065 cm(-1) has been measured with Doppler-limited resolution at a temperature of similar to 195 K on a difference-frequency laser spectrometer, and on a high-resolution Fourier transform instrument at room temperature as well as in a molecular jet at similar to 20 K. From a detailed rotational analysis of this complex band, based on an extension of the model of the rotational-torsional interactions described by P. R. Bunker and C. di Lauro (Chern. Phys. 190, 159-169, 1995), accurate spectroscopic constants were determined for the upper CH stretching state, along with values for the first three components of the Fourier expansion for the torsional potential in the ground state, and for six components of this potential in the upper state. Over 700 lines assigned to 37 well resolved subbands plus 25 additional unresolved line-like Q-branches were fitted with an overall standard deviation of 0.0024 cm(-1). The results yield a value of 6.316 +/- 0.034 cm(-1) for the barrier to internal rotation in the ground state, and 6.643 +/- 0.006 cm(-1) for the C-H stretching state. This value for the ground state barrier is somewhat higher than that recently determined from an analysis of the CH3 rocking band by P. R. Bunker et al. (J. Mol. Spectrosc. 162, 142-151, 1993). (C) 1996 Academic Press, Inc. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. ACAD SCI CZECH REPUBL,J HEYROVSKY INST PHYS CHEM,CR-18223 PRAGUE,CZECH REPUBLIC. RP Pliva, J (reprint author), PENN STATE UNIV,DEPT PHYS,104 DAVEY LAB,UNIVERSITY PK,PA 16802, USA. NR 23 TC 11 Z9 11 U1 0 U2 2 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD NOV PY 1996 VL 180 IS 1 BP 15 EP 25 DI 10.1006/jmsp.1996.0220 PG 11 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA VP270 UT WOS:A1996VP27000003 ER PT J AU Liu, PK Hsu, CY Dizdaroglu, M Floyd, RA Kow, YW Karakaya, A Rabow, LE Cui, JK AF Liu, PK Hsu, CY Dizdaroglu, M Floyd, RA Kow, YW Karakaya, A Rabow, LE Cui, JK TI Damage, repair, and mutagenesis in nuclear genes after mouse forebrain ischemia-reperfusion SO JOURNAL OF NEUROSCIENCE LA English DT Review DE apoptosis; brain; mutation; dementia; oxidative stress; stroke ID FAMILIAL ALZHEIMERS-DISEASE; FOCAL CEREBRAL-ISCHEMIA; CONJUGATED SUPEROXIDE-DISMUTASE; DNA POLYMERASE-BETA; PRIMARY NEURONAL DEGENERATIONS; HYDROXYL RADICAL GENERATION; TIRILAZAD MESYLATE U-74006F; DUCHENNE MUSCULAR-DYSTROPHY; PROGRAMMED CELL-DEATH; NITRIC-OXIDE AB To determine whether oxidative stress after cerebral ischemia-reperfusion affects genetic stability in the brain, we studied mutagenesis after forebrain ischemia-reperfusion in Big Blue transgenic mice (male C57BL/6 strain) containing a reporter lad gene, which allows detection of mutation frequency. The frequency of mutation in this reporter lad gene increased from 1.5 to 7.7 (per 100,000) in cortical DNA after 30 min of forebrain ischemia and 8 hr of reperfusion and remained elevated at 24 hr reperfusion. Eight DNA lesions that are characteristic of DNA damage mediated by free radicals were detected. Four mutagenic lesions (2,6-diamino-4-hydroxy-5-formamidopyrimidine 8-hydroxyadenine, 5-hydroxycytosine, and 8-hydroxyguanine) examined by gas chromatography/mass spectrometry and one corresponding 8-hydroxy-2'-deoxyguanosine by a method of HPLC with electrochemical detection increased in cortical DNA two- to fourfold (p < 0.05) during 10-20 min of reperfusion. The damage to gamma-actin and DNA polymerase-beta genes was detected within 20 min of reperfusion based on the presence of formamidopyrimidine DNA N-glycosylase-sensitive sites. These genes became resistant to the glycosylase within 4-6 hr of reperfusion, suggesting a reduction in DNA damage and presence of DNA repair in nuclear genes. These results suggest that nuclear genes could be targets of free radicals. C1 UNIV WASHINGTON,DEPT NEUROL,ST LOUIS,MO 63110. NIST,CHEM SCI & TECHNOL LAB,GAITHERSBURG,MD 20899. OKLAHOMA MED RES FDN,OKLAHOMA CITY,OK 73104. EMORY UNIV,SCH MED,DEPT RADIAT ONCOL,ATLANTA,GA 30335. ANKARA UNIV,FAC PHARM,TR-06100 ANKARA,TURKEY. RP Liu, PK (reprint author), BAYLOR COLL MED,DIV RESTORAT NEUROL & HUMAN NEUROBIOL,NEUROBIOL LAB,1 BAYLOR PLAZA,ROOM S815,HOUSTON,TX 77030, USA. OI Hsu, Chung Y./0000-0002-5632-2733 FU NINDS NIH HHS [NS28995, NS25545, NS34810, P01 NS032636, R01 NS034810, R01 NS034810-04, R01 NS034810-04S1] NR 108 TC 184 Z9 190 U1 1 U2 5 PU OXFORD UNIV PRESS INC PI CARY PA JOURNALS DEPT, 2001 EVANS RD, CARY, NC 27513 SN 0270-6474 J9 J NEUROSCI JI J. Neurosci. PD NOV 1 PY 1996 VL 16 IS 21 BP 6795 EP 6806 PG 12 WC Neurosciences SC Neurosciences & Neurology GA VN618 UT WOS:A1996VN61800018 PM 8824320 ER PT J AU Tolman, HL Chalikov, D AF Tolman, HL Chalikov, D TI Source terms in a third-generation wind wave model SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID NONLINEAR ENERGY-TRANSFER; BOUNDARY-LAYER; SEA; SPECTRUM; PARAMETERIZATIONS; COMPUTATIONS; PRESSURE; BALANCE; GROWTH; STRESS AB A new third-generation ocean wind wave model is presented. This model is based on previously developed input and nonlinear interaction source terms and a new dissipation source term. It is argued that the dissipation source term has to be modeled using two explicit constituents. A low-frequency dissipation term analogous to wave energy loss due to oceanic turbulence is therefore augmented with a diagnostic high-frequency dissipation term. The dissipation is tuned for the model to represent idealized fetch-limited growth behavior. The new model results in excellent growth behavior from extremely short fetches up to full development. For intermediate to long fetches results are similar to those of WAM, but for extremely short fetches the present model presents a significant improvement (although the poor behavior of WAM appears to be related to correctable numerical constraints). The new model furthermore gives smoother results and appears less sensitive to numerical errors. Finally, limitations of the present source terms and possible improvements are discussed. RP Tolman, HL (reprint author), NCEP,NOAA,ENVIRONM MODELING CTR,OCEAN MODELING BRANCH,5200 AUTH RD,ROOM 209,CAMP SPRINGS,MD 20746, USA. NR 36 TC 235 Z9 247 U1 1 U2 8 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0022-3670 J9 J PHYS OCEANOGR JI J. Phys. Oceanogr. PD NOV PY 1996 VL 26 IS 11 BP 2497 EP 2518 DI 10.1175/1520-0485(1996)026<2497:STIATG>2.0.CO;2 PG 22 WC Oceanography SC Oceanography GA VV574 UT WOS:A1996VV57400012 ER PT J AU Cage, ME Jeffery, A AF Cage, ME Jeffery, A TI Intrinsic capacitances and inductances of quantum Hall effect devices SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE impedance standard; internal capacitance; intrinsic impedance; kinetic inductance; magnetic inductance; quantum Hail effect; two-dimensional electron gas ID AC MEASUREMENTS; EFFECT SAMPLE; RESISTANCE; GAAS/ALXGA1-XAS AB Analytic solutions are obtained for the internal capacitances, kinetic inductances, and magnetic inductances of quantum Hall effect devices to investigate whether or not the quantized Hall resistance is the only intrinsic impedance of importance in measurements of the ac quantum Hall effect. ?he internal capacitances and inductances are obtained by using the results of Cage and Lavine, who determined the current and potential distributions across the widths of quantum Hall effect devices. These intrinsic capacitances and inductances produce small out-of-phase impedance corrections to the in-phase quantized Hail resistance and to the in-phase longitudinal resistance. RP Cage, ME (reprint author), NIST, ELECT & ELECT ENGN LAB, DIV ELECT, GAITHERSBURG, MD 20899 USA. NR 19 TC 13 Z9 13 U1 0 U2 0 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD NOV-DEC PY 1996 VL 101 IS 6 BP 733 EP 744 DI 10.6028/jres.101.071 PG 12 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA WH018 UT WOS:A1996WH01800001 PM 27805074 ER PT J AU Shirley, EL Datla, RU AF Shirley, EL Datla, RU TI Optimally toothed apertures for reduced diffraction SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE aperture; computation; diffraction; parallel processing; tooth AB We model diffraction errors found when using toothed apertures [L. P. Boivin, Reduction of diffraction errors in radiometry by means of toothed apertures, Appl. Opt. 17, 3323-3328 (1978)]. Using toothed (cf. circular) apertures minimizes diffraction by inducing destructive interference within the diffracted signal. Since diffraction effects can be quite complicated, their over-all reduction may help limit uncertainties in, say calibrations. Our analysis yields three principles to guide design of nonlimiting (baffle) apertures which minimize diffraction. We performed detailed diffraction calculations within scalar (Kirchoff) diffraction theory, using parallel-computing resources at the National institute of Standards and Technology. RP Shirley, EL (reprint author), NIST, PHYS LAB, OPT TECHNOL DIV, GAITHERSBURG, MD 20899 USA. NR 13 TC 6 Z9 6 U1 0 U2 0 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD NOV-DEC PY 1996 VL 101 IS 6 BP 745 EP 753 DI 10.6028/jres.101.072 PG 9 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA WH018 UT WOS:A1996WH01800002 PM 27805075 ER PT J AU Fine, J Szymonski, M Kolodziej, J Yoshitake, M Franzreb, K AF Fine, J Szymonski, M Kolodziej, J Yoshitake, M Franzreb, K TI Bombardment induced electron-capture processes at sodium halide surfaces SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE autoionization; collisional excitation; defect production; electron capture collisions; electron spectra; ion bombardment; sodium chloride; surfaces ID MOLECULAR-DYNAMICS SIMULATION; SCATTERED-ION FRACTIONS; INDUCED AUGER EMISSION; STIMULATED DESORPTION; AUTOIONIZING STATES; COLLISIONAL EXCITATION; INELASTIC PROCESSES; ATOM COLLISIONS; PHOTON-EMISSION; ALKALI-HALIDES AB Discrete features observed in the energy distribution of electrons emitted from ion-bombarded sodium halide surfaces can be attributed to a new type of collisional deexcitation mechanism. Such a mechanism involves sodium atoms in bombardment-excited autoionizing states that are the result of cascade collisions within the crystal lattice. This deexcitation process, in contrast to that for a metal, is not simply a consequence of the inner-shell lifetime of the initial collisionally excited sodium Na-+* ion. Rather, the deexcitation consists of a sequence of lattice collisions during which the excited Na-+* ion captures an electron to form the inner-shell-excited Na-0* states responsible for the observed transitions. The formation of such autoionizing Na0+ states is described within the framework of a new model in which excitation processes and localized collisional electron-transfer mechanisms are taken into account. These localized electron-transfer processes make possible new channels for electronic deexcitation, chemical dissociation, and defect production; they are critical for understanding inelastic ion-surface collisions in solids. C1 JAGIELLONIAN UNIV, INST PHYS, PL-30549 KRAKOW, POLAND. NATL RES INST MET, TSUKUBA, IBARAKI 305, JAPAN. UNIV WESTERN ONTARIO, LONDON, ON N6A 5B7, CANADA. RP Fine, J (reprint author), NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. NR 97 TC 5 Z9 5 U1 0 U2 0 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD NOV-DEC PY 1996 VL 101 IS 6 BP 755 EP 778 DI 10.6028/jres.101.073 PG 24 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA WH018 UT WOS:A1996WH01800003 PM 27805076 ER PT J AU Ferraiolo, K Ippolito, LM AF Ferraiolo, K Ippolito, LM TI COMPASS '96 - The Eleventh Annual Conference on Computer Assurance, Gaithersburg, MD - June 17-21, 1996 SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Editorial Material C1 NATL INST STAND & TECHNOL, COMP SYST LAB, GAITHERSBURG, MD 20899 USA. RP Ferraiolo, K (reprint author), ARCA SYST INC, COLUMBIA, MD 21044 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD NOV-DEC PY 1996 VL 101 IS 6 BP 791 EP 796 DI 10.6028/jres.101.075 PG 6 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA WH018 UT WOS:A1996WH01800005 PM 27805078 ER PT J AU Vanderah, TA AF Vanderah, TA TI Workshop on Materials and Measurements for Wireless Communications, Gaithersburg, MD - November 7-8, 1995 SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Editorial Material ID MICROWAVE RP Vanderah, TA (reprint author), NATL INST STAND & TECHNOL, DIV CERAM, GAITHERSBURG, MD 20899 USA. NR 7 TC 2 Z9 2 U1 0 U2 0 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD NOV-DEC PY 1996 VL 101 IS 6 BP 797 EP 802 DI 10.6028/jres.101.076 PG 6 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA WH018 UT WOS:A1996WH01800006 PM 27805079 ER PT J AU Chiang, MYM McKenna, GB AF Chiang, MYM McKenna, GB TI Hygrothermal Effects on the Performance of Polymers and Polymeric Composites, Gaithersburg, MD - September 21-22, 1995 SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Editorial Material RP Chiang, MYM (reprint author), NATL INST STAND & TECHNOL, DIV POLYMERS, MAT SCI & ENGN LAB, GAITHERSBURG, MD 20899 USA. RI McKenna, Gregory/O-1134-2013 OI McKenna, Gregory/0000-0002-5676-9930 NR 0 TC 5 Z9 5 U1 0 U2 1 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD NOV-DEC PY 1996 VL 101 IS 6 BP 803 EP 819 DI 10.6028/jres.101.077 PG 17 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA WH018 UT WOS:A1996WH01800007 PM 27805080 ER PT J AU Byars, BW Allen, PM Bingham, NL AF Byars, BW Allen, PM Bingham, NL TI A portable rainfall simulator for assessing infiltration SO JOURNAL OF SOIL AND WATER CONSERVATION LA English DT Article ID RANGELAND AB A portable rainfall simulator has been developed for use in field infiltration experiments. The rainfall simulator is built using readily available components, is easily transportable, and requires a setup time of approximately 10 minutes. Field testing results have shown that the rainfall simulator gives comparable runoff and loss rater to those of similar sized plots monitored under natural rainfall conditions. C1 NATL WEATHER SERV,ARKANSAS RED BASIN RIVER FORECAST CTR,TULSA,OK 74128. RP Byars, BW (reprint author), BAYLOR UNIV,DEPT GEOL,POB 97354,WACO,TX 76798, USA. NR 9 TC 1 Z9 1 U1 1 U2 2 PU SOIL WATER CONSERVATION SOC PI ANKENY PA 7515 N E ANKENY RD, ANKENY, IA 50021-9764 SN 0022-4561 J9 J SOIL WATER CONSERV JI J. Soil Water Conserv. PD NOV-DEC PY 1996 VL 51 IS 6 BP 508 EP 510 PG 3 WC Ecology; Soil Science; Water Resources SC Environmental Sciences & Ecology; Agriculture; Water Resources GA WF476 UT WOS:A1996WF47600017 ER PT J AU Tewary, VK Mahapatra, M Fortunko, CM AF Tewary, VK Mahapatra, M Fortunko, CM TI Green's function for anisotropic half-space solids in frequency space and calculation of mechanical admittance SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article ID COMPUTATIONALLY EFFICIENT REPRESENTATION; WAVES AB The three-dimensional delta-function representation for the elastodynamic Green's function of anisotropic half-space solids is extended to the frequency space. The Green's function is used to calculate the frequency dependence of the elastic waveforms due to a harmonic source on the free surface of an anisotropic half-space solid. An expression for the point mechanical admittance of solids is derived. Numerical results are reported for anisotropic half-space solids exhibiting cubic symmetry and an orthotropic carbon fiber composite. The real part of the admittance of a half-space solid is found to be proportional to the square of the frequency. RP Tewary, VK (reprint author), NATL INST STAND & TECHNOL,DIV MAT RELIABIL,BOULDER,CO 80303, USA. NR 14 TC 7 Z9 7 U1 0 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD NOV PY 1996 VL 100 IS 5 BP 2960 EP 2963 DI 10.1121/1.417107 PG 4 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA VT753 UT WOS:A1996VT75300006 ER PT J AU Tewary, VK Fortunko, CM AF Tewary, VK Fortunko, CM TI Theory of elastic waves in three-dimensional anisotropic plates SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article ID LEAKY LAMB WAVES; COMPUTATIONALLY EFFICIENT REPRESENTATION; ACOUSTIC-EMISSION; GREENS-FUNCTIONS; TRANSIENT WAVES; COMPOSITE PLATE; SOLIDS; PROPAGATION; INTERFACE AB The delta-function representation of the elastodynamic Green's function is used to calculate three-dimensional time-dependent waveforms for an elastic pulse propagating in an anisotropic plate of arbitrary thickness for a point source of stress on a surface. The Green's function includes the effects of mode coupling and mode conversion, and multireflections in the plate, As an example, the method is applied to anisotropic plates exhibiting cubic and orthotropic symmetries. Numerical results are presented for time-dependent waveforms in model cubic plates and in an orthotropic carbon fiber composite plate. RP Tewary, VK (reprint author), NATL INST STAND & TECHNOL,DIV MAT RELIABIL,BOULDER,CO 80303, USA. NR 33 TC 1 Z9 1 U1 2 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD NOV PY 1996 VL 100 IS 5 BP 2964 EP 2968 DI 10.1121/1.417108 PG 5 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA VT753 UT WOS:A1996VT75300007 ER PT J AU Mitchell, JA Pitner, WR Hussey, CL Stafford, GR AF Mitchell, JA Pitner, WR Hussey, CL Stafford, GR TI Electrodeposition of cobalt and cobalt-aluminum alloys from a room temperature chloroaluminate molten salt SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID RING-DISK ELECTRODE; STRIPPING VOLTAMMETRY; METALLIC-GLASS; PHASE; FILMS; PH AB The electrodeposition of magnetic cobalt-aluminum alloys was investigated in the Lewis acidic aluminum chloride-1-methyl-3-ethylimidazolium chloride [60.0-40.0 mole percent (m/o)] molten salt containing electrogenerated Co(II) at 25 degrees C. Rotating disk electrode voltammetry indicated that it is possible to produce alloy deposits containing up to 62 atomic (a/o) aluminum at potentials positive of that for the bulk deposition of aluminum. The onset of the underpotential-driven aluminum codeposition process occurred at around 0.40 V vs. the Al/Al(III) couple in a 5.00 mmol liter Co(II) solution but decreased as the Co(II) concentration increased. The Go-AL alloy composition displayed an inverse dependence on the Co(II) concentration but tended to become independent of concentration as the potential was decreased to 0 V. A rotating ring-disk electrode voltammetry technique was developed to analyze the composition and structure of the Co-Al alloy deposits. This technique takes advantage of the fact that the mass-transport-limited reduction of cobalt(II) occurs at potentials considerably more positive than that at which aluminum codeposition occurs. Scanning electron microscopy and energy dispersive x-ray analysis of bulk electrodeposits revealed that deposit morphology depends strongly upon aluminum content/deposition potential; deposits produced at 0.40 V from 50.0 mmol liter(-1) Co(II) solutions consisted of 10 to 20 mu m diam multifaceted nodules of pure hcp cobalt, whereas those obtained at 0.20 V were dense and fine grained, containing about 4 a/o Al. Deposits produced at 0 V had the visual appearance of a loosely adherent black powder. X-ray diffraction measurements revealed a lattice expansion and a decrease in grain size as the hcp cobalt was alloyed with increasing amounts of aluminum. C1 NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899. RP Mitchell, JA (reprint author), UNIV MISSISSIPPI,DEPT CHEM,UNIVERSITY,MS 38677, USA. NR 36 TC 64 Z9 69 U1 0 U2 20 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 10 SOUTH MAIN STREET, PENNINGTON, NJ 08534 SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD NOV PY 1996 VL 143 IS 11 BP 3448 EP 3455 DI 10.1149/1.1837235 PG 8 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA VU821 UT WOS:A1996VU82100014 ER PT J AU Fogarty, G Steiner, B CroninGolomb, M Laor, U Garrett, MH Martin, J Uhrin, R AF Fogarty, G Steiner, B CroninGolomb, M Laor, U Garrett, MH Martin, J Uhrin, R TI Antiparallel ferroelectric domains in photorefractive barium titanate and strontium barium niobate observed by high-resolution x-ray diffraction imaging SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article; Proceedings Paper CT 5th Topical Meeting on Photorefractive Materials, Effects, and Devices CY JUN, 1995 CL ESTES PK, CO ID SRXBA1-XNB2O6; TOPOGRAPHY; CRYSTALS AB Antiparallel ferraelectric (180-deg) domains have been observed by high-resolution x-ray diffraction imaging in barium titanate and strontium barium niobate. This technique permits the imaging of domains in thick (1-mm) samples with high spatial resolution (1 mu m). These domains are visible in both Laue and Bragg geometry but only in those diffraction images for which the diffraction vector has some component along the [001] axis (optical axis). The origin of the domain contrast is explained in terms of the unit cell symmetry and a new coupled-mode view of the dynamical theory of x-ray diffraction. This model also permits determination of domain location relative to the sample surfaces through the analysis of the domain fringe contrast. (C) 1996 Optical Society of America. C1 TUFTS UNIV, CTR ELECTROOPT TECHNOL, MEDFORD, MA 02155 USA. BEN GURION UNIV NEGEV, NUCL RES CTR, IL-84105 BEER SHEVA, ISRAEL. DELTRON CRYSTAL IND, DOVER, NJ 07801 USA. RP Fogarty, G (reprint author), NIST, GAITHERSBURG, MD 20899 USA. RI Cronin-Golomb, Mark/A-5430-2012 OI Cronin-Golomb, Mark/0000-0002-8936-4358 NR 26 TC 34 Z9 35 U1 0 U2 4 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0740-3224 J9 J OPT SOC AM B JI J. Opt. Soc. Am. B-Opt. Phys. PD NOV PY 1996 VL 13 IS 11 BP 2636 EP 2643 DI 10.1364/JOSAB.13.002636 PG 8 WC Optics SC Optics GA VT941 UT WOS:A1996VT94100033 ER PT J AU Tang, CM Swyden, TA Thomason, KA Yadon, LN Temple, D Ball, CA Palmer, WD Mancusi, JE Vellenga, D McGuire, GE AF Tang, CM Swyden, TA Thomason, KA Yadon, LN Temple, D Ball, CA Palmer, WD Mancusi, JE Vellenga, D McGuire, GE TI Emission measurements and simulation of silicon field-emitter arrays with linear planar lenses SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article AB Results of beam collimation experiments on linear held-emitter arrays with linear planar lenses are summarized. The electron beam is imaged on a phosphor screen. In general, as lens voltage is reduced relative to the gate voltage, the elliptically shaped screen images narrow, becoming fine lines with emission currents showing only modest reductions. This reduction of emission current can be overcome by increasing the gate voltage only a few volts without affecting beam collimation. As the lens voltage is reduced, screen current decreases relative to emission current while gate current increases, indicating that some emitted electrons in this Linear lens geometry cannot propagate to the anode screen. Experimental data and qualitative modeling are in fair agreement. (C) 1996 American Vacuum Society. C1 NIST,GAITHERSBURG,MD 20899. FM TECHNOL INC,FAIRFAX,VA 22032. MCNC,RES TRIANGLE PK,NC 27709. RP Tang, CM (reprint author), CREATY MICROTECH INC,POTOMAC,MD 20854, USA. RI Palmer, William/E-2296-2012 NR 17 TC 19 Z9 20 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD NOV-DEC PY 1996 VL 14 IS 6 BP 3455 EP 3459 DI 10.1116/1.588779 PG 5 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA VZ361 UT WOS:A1996VZ36100008 ER PT J AU Liang, QF Johnson, LE Mohan, S AF Liang, QF Johnson, LE Mohan, S TI Autoregressive decision rule in aggregated reservoir operation SO JOURNAL OF WATER RESOURCES PLANNING AND MANAGEMENT-ASCE LA English DT Article ID WATER AB Lag-1 correlation for inflow between consecutive periods is considered into reservoir model in many publications. This consideration greatly improves the reservoir models to incorporate the uncertainty of inflow. However, no publication was found to incorporate a correlation relationship for releases between consecutive periods to improve the operating policy for reservoir operations. This paper presents a methodology of autoregressive decision rule for an aggregated reservoir operation as a surrogate of a multireservoir system of the Upper Colorado River Basin. The method incorporates a lag-1 correlation for the releases between consecutive periods with the optimal operating policy solved by stochastic dynamic program. The decision rules with and without incorporation of the autoregressive correlation for the releases were then used in simulated operation of the reservoir with historical inflow records to evaluate their relative effectiveness, The results showed that the autoregressive decision rule yields more stable and higher reliability of annual water supply for the aggregated reservoir operations. C1 UNIV COLORADO,DEPT CIVIL ENGN,DENVER,CO 80217. INDIAN INST TECHNOL,DEPT CIVIL ENGN,MADRAS,TAMIL NADU,INDIA. RP Liang, QF (reprint author), COLORADO STATE UNIV,NOAA,FSL,DEPT CIVIL ENGN,FT COLLINS,CO 80523, USA. RI S., Mohan/M-1705-2015 NR 13 TC 1 Z9 1 U1 0 U2 1 PU ASCE-AMER SOC CIVIL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 SN 0733-9496 J9 J WATER RES PL-ASCE JI J. Water Resour. Plan. Manage.-ASCE PD NOV-DEC PY 1996 VL 122 IS 6 BP 438 EP 440 DI 10.1061/(ASCE)0733-9496(1996)122:6(438) PG 3 WC Engineering, Civil; Water Resources SC Engineering; Water Resources GA VN872 UT WOS:A1996VN87200007 ER PT J AU Daskalakis, KD AF Daskalakis, KD TI Variability of metal concentrations in oyster tissue and implications to biomonitoring SO MARINE POLLUTION BULLETIN LA English DT Article ID MYTILUS-EDULIS; MUSSEL WATCH; CONTAMINATION; SILVER; AGE AB Metal concentrations in individual oysters were estimated in order to assess the among-individuals metal variability In a geographically confined area. American oysters (Crassostrea virginica) were collected from three sites on the Potomac River, Maryland, and the soft tissues of individuals was analysed for Ag, Cd, Cu, Fe, Ni, Pb and Zn. At all sites metal concentrations were highly variable with the coefficient of variation (CV) between 15 and 55%, the three site mean increasing as follows: Fe; Cd; Ni; Zn; Pb; Ag; Cu. Excluding Pb, the analytical contribution to the total variance was about 2%. Bootstrap analysis, a statistical resampling procedure with replacement, was used to estimate population parameters for pooled samples. Simulated sampling of 10 000 pooled samples verified that the sampling error decreases significantly with increasing numbers of individuals per pool. The confidence interval of means for samples consisting of 20 oysters varied from +/-5% to +/-20% (p<0.05), depending on metal and site. The confidence interval of means increased by a factor of approximately 1.5 when 10 individuals were used instead of 20, and decreased by a factor of 0.6 when 50 oysters were used per pooled sample. These results indicate that if analyses of individuals are precluded, increased size of pooled samples is a low cost option for increasing the ability of monitoring programmes to detect changes in environmental contaminants. Published by Elsevier Science Ltd RP NOAA, NATL STATUS & TRENDS PROGRAM, NOS, ORCA21, 1305 EAST WEST HWY, SILVER SPRING, MD 20910 USA. NR 16 TC 29 Z9 31 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0025-326X EI 1879-3363 J9 MAR POLLUT BULL JI Mar. Pollut. Bull. PD NOV PY 1996 VL 32 IS 11 BP 794 EP 801 DI 10.1016/S0025-326X(96)00042-2 PG 8 WC Environmental Sciences; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA VY624 UT WOS:A1996VY62400017 ER PT J AU Paul, RL Privett, HM Lindstrom, RM Richards, WJ Greenberg, RR AF Paul, RL Privett, HM Lindstrom, RM Richards, WJ Greenberg, RR TI Determination of hydrogen in titanium alloys by gold neutron prompt gamma activation analysis SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article AB Cold neutron prompt gamma-ray activation analysis (CNPGAA) has proven useful for the analysis of hydrogen in titanium alloys. The analysis is nondestructive, measures the entire sample, and the results are independent of the chemical form of hydrogen present. We have used the technique to measure H mass fractions as low as 50 mg/kg in titanium-alloy jet-engine compressor blades and to measure hydrogen in standards for neutron tomography. C1 PRATT & WHITNEY AIRCRAFT,W PALM BEACH,FL 33410. NUCL MED SECT,MCCLELLAN AFB,CA 95652. RP Paul, RL (reprint author), NIST,DIV ANALYT CHEM,GAITHERSBURG,MD 20899, USA. NR 16 TC 17 Z9 17 U1 3 U2 4 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 1073-5623 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD NOV PY 1996 VL 27 IS 11 BP 3682 EP 3687 DI 10.1007/BF02595460 PG 6 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA VT798 UT WOS:A1996VT79800033 ER PT J AU Schlund, BJ Suehle, J Messick, C Chaparala, P AF Schlund, BJ Suehle, J Messick, C Chaparala, P TI A new physics-based model for time-dependent dielectric breakdown SO MICROELECTRONICS AND RELIABILITY LA English DT Article; Proceedings Paper CT 7th European Symposium on Reliability of Electron Devices, Failure Physics and Analysis (ESREF 96) CY OCT 08-11, 1996 CL ENSCHEDE, NETHERLANDS SP IEEE, Electron Devices Soc AB A physics-based model for time dependent dielectric breakdown has been developed, and is presented along with test data obtained by NIST on oxides provided by National Semiconductor. Testing included fields from 5.4 MV/cm to 12.7 MV/cm, and temperatures ranging from 60 degrees C to 400 degrees C. The physics, mathematical model, and test data, all confirm a linear, rather than an inverse field dependence. The primary influence on oxide breakdown was determined to be due to the dipole interaction energy of the field with the orientation of the molecular dipoles in the dielectric. The resultant failure mechanism is shown to be the formation and coalescence of vacancy defects, similar to that proposed by Dumin et al. Copyright (C) 1996 Elsevier Science Ltd C1 NIST,GAITHERSBURG,MD 20899. NATL SEMICOND CORP,W JORDAN,UT 84088. NATL SEMICOND CORP,SANTA CLARA,CA 95052. RP Schlund, BJ (reprint author), MOTOROLA GSTG,8201 E MCDOWELL RD,SCOTTSDALE,AZ 85252, USA. NR 7 TC 7 Z9 7 U1 1 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0026-2714 J9 MICROELECTRON RELIAB JI Microelectron. Reliab. PD NOV-DEC PY 1996 VL 36 IS 11-12 BP 1655 EP 1658 DI 10.1016/0026-2714(96)00168-0 PG 4 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA VN502 UT WOS:A1996VN50200012 ER PT J AU Shapiro, LJ AF Shapiro, LJ TI The motion of Hurricane Gloria: A potential vorticity diagnosis SO MONTHLY WEATHER REVIEW LA English DT Article ID ELECTROSTATICS ANALOGY; MOVEMENT; VORTEX; EVOLUTION AB Multilevel, multinested analyses of Hurricane Gloria of 1985 are the most comprehensive kinematic dataset yet developed for a single hurricane. A piecewise inversion technique is used with these analyses and the nonlinear balance equation to deduce the three-dimensional distribution of potential vorticity (PV) that contributed to the deep-layer mean (DLM) how that steered Gloria toward the northwest. The background state is taken to be the azimuthally averaged winds in balance with a geopotential distribution on an f plane. Advantage is taken of the near-linearity of the weak asymmetries near the hurricane's core and of PV in the environment. Thus, ad hoc aspects of the linearization required by other investigators are effectively eliminated. Removal of the hurricane Vortex and the use of a climatological mean background state are avoided as well. The insensitivity of the results to the imposed lateral boundary conditions is also demonstrated. Wind anomalies attributable to pieces of anomalous PV restricted to cylinders of different radii centered on the hurricane are evaluated. The DLM wind that steered Gloria to the northwest is primarily attributable to PV anomalies confined within a cylinder of radius 1000 km and levels 500 mb and above, including positive anomalies associated with a cold low over Cuba. The vector difference between the hurricane's observed motion and the DLM wind at Gloria's center attributable to these PV anomalies is 1.0 m s(-1), explaining more than five-sixths of the hurricane's 6.2 m s(-1) motion. Implications for measurements required to establish short-term changes of the environmental steering dow are considered. Difficulties in the interpretation of results are discussed for PV anomalies that are confined to noncircular regions; the implication for other studies is considered as well. RP Shapiro, LJ (reprint author), NOAA,ATLANTIC OCEANOG & METEOROL LAB,HURRICANE RES DIV,4301 RICKENBECKER CAUSEWAY,MIAMI,FL 33149, USA. NR 20 TC 27 Z9 31 U1 3 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD NOV PY 1996 VL 124 IS 11 BP 2497 EP 2508 DI 10.1175/1520-0493(1996)124<2497:TMOHGA>2.0.CO;2 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VT172 UT WOS:A1996VT17200006 ER PT J AU Zupanski, M AF Zupanski, M TI A preconditioning algorithm for four-dimensional variational data assimilation SO MONTHLY WEATHER REVIEW LA English DT Article ID STEP-MOUNTAIN COORDINATE; ANALYSIS SYSTEM; MODEL; STORAGE AB A preconditioning method suitable for use in four-dimensional variational (4DVAR) data assimilation is proposed. The method is a generalization of the preconditioning previously developed by the author, now designed to include direct observations, as well as different forms of the cost function. The original approach was based on an estimate of the ratio of the expected decrease of the cost function and of the gradient norm, derived from an approximate Taylor series expansion of the cost function. The generalized method employs only basic linear functional analysis, still preserving the efficiency of the original method. The preconditioning is tested in a realistic 4DVAR assimilation environment: the data are direct observations operationally used at the National Centers for Environmental prediction (formerly the National Meteorological Center), the forecast model is a full-physics regional eta model, and the adjoint model includes all physics, except radiation. The results of five 4DVAR data assimilation experiments, using a memoryless quasi-Newton minimization algorithm, show a significant benefit of the new preconditioning. On average, the minimization algorithm converges in about 20-25 iterations. In particular, after only 10 iterations, about 95% of the cost function decrease was achieved in all five cases. Especially encouraging is the fact that these results are obtained with physical processes present in the adjoint model. RP Zupanski, M (reprint author), NATL CTR ENVIRONM PREDICT,NCEP UCAR VISITOR RES PROGRAM,WWB2,ROOM 206,5200 AUTH RD,CAMP SPRINGS,MD 20746, USA. NR 39 TC 25 Z9 26 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD NOV PY 1996 VL 124 IS 11 BP 2562 EP 2573 DI 10.1175/1520-0493(1996)124<2562:APAFFD>2.0.CO;2 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VT172 UT WOS:A1996VT17200011 ER PT J AU Muir, WD Coley, TC AF Muir, WD Coley, TC TI Diet of yearling chinook salmon and feeding success during downstream migration in the Snake and Columbia Rivers SO NORTHWEST SCIENCE LA English DT Article ID ATLANTIC SALMON; SALAR; TROUT; STEELHEAD; PREDATION; SMOLTS; PARR; PREY AB The objectives of this study were to characterize anti compare the stomach contents and feeding success of yearling chinook salmon smolts (Oncorhynchus tshawytscha), during their downstream migration at three sites in the Snake and Columbia Rivers. From 1987 to 1991, 26 to 38% of the yearling chinook salmon smolts sampled as they passed Lower Granite Dam, the first dam encountered by migrants in the Snake River, had empty stomachs, in 1991, smolts were sampled further downstream at McNary and Bonneville Dams on the Columbia River on thr same sample dates. Empty stomachs occurred in 3% and 5% of these fish, respectively, and overall stomach fullness values were significantly higher. Smolts ale primarily dipterans (chironomids) al Lower Granite Dam; cladocerans, homopterans, and dipterans at McNary Dam: anti amphipods and dipterans at Bonneville Dam-taxa typical of impounded waters, A series of dams on the Snake and Columbia Rivers has altered the conditions and habitat available for migrating juvenile salmonids and contributed to their decline. Large numbers of hatchery smolts, long residence times, altered food resources, and reservoir morphology may contribute to poor feeding success near Lower Granite Dam and could lead to reduced smolt survival. RP Muir, WD (reprint author), NOAA,NATL MARINE FISHERIES SERV,NW FISHERIES SCI CTR,COASTAL ZONE & ESTUARINE STUDIES DIV,SEATTLE,WA 98112, USA. NR 35 TC 13 Z9 14 U1 2 U2 13 PU WASHINGTON STATE UNIV PI PULLMAN PA PO BOX 645910, PULLMAN, WA 99164-5910 SN 0029-344X J9 NORTHWEST SCI JI Northwest Sci. PD NOV PY 1996 VL 70 IS 4 BP 298 EP 305 PG 8 WC Ecology SC Environmental Sciences & Ecology GA WB997 UT WOS:A1996WB99700002 ER PT J AU Danon, Y Moore, MS Koehler, PE Littleton, PE Miller, GG Ott, MA Rowton, LJ Taylor, WA Wilhelmy, JB Yates, MA Carlson, AD Hill, NW Harper, R Hilko, R AF Danon, Y Moore, MS Koehler, PE Littleton, PE Miller, GG Ott, MA Rowton, LJ Taylor, WA Wilhelmy, JB Yates, MA Carlson, AD Hill, NW Harper, R Hilko, R TI Fission cross-section measurements of the odd-odd isotopes Pa-232, Np-238, and Np-236 SO NUCLEAR SCIENCE AND ENGINEERING LA English DT Article AB Transmutation of actinide waste into fission products could be enhanced by using resonance fission of odd-odd target materials; those of interest are Pa-232, Np-238, and Am-242. Fission cross-section measurements of two of these short-lived materials were performed al Los Alamos National Laboratory. Samples were produced by the (d,2n) reaction in the Los Alamos ion Beam Facility followed by fast radiochemistry to separate the odd-odd target of interest. The fission cross section of the nanogram samples was measured in a high intensity pulsed neutron beam produced by 800-MeV proton spallation. Using this procedure, the fission cross sections of the 1.3-day Pa-232 and 2.1-day Np-238 were successfully measured in the energy range from 0.01 eV to 50 keV. The fission cross section of the relatively long-life isotope Np-236 was also measured in the same system while the short half-life isotopes were being prepared. The results and resonance analysis are presented. C1 RENSSELAER POLYTECH INST,DEPT NUCL ENGN & ENGN PHYS,TROY,NY 12180. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. NIST,GAITHERSBURG,MD 20899. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. EG&G ENERGY MEASUREMENTS INC,LOS ALAMOS,NM 87544. RI Danon, Yaron/B-5159-2009; OI Koehler, Paul/0000-0002-6717-0771 NR 9 TC 4 Z9 6 U1 1 U2 2 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 SN 0029-5639 J9 NUCL SCI ENG JI Nucl. Sci. Eng. PD NOV PY 1996 VL 124 IS 3 BP 482 EP 491 PG 10 WC Nuclear Science & Technology SC Nuclear Science & Technology GA VQ601 UT WOS:A1996VQ60100010 ER PT J AU Schenck, PK Hastie, JW Paul, AJ Bonnell, DW AF Schenck, PK Hastie, JW Paul, AJ Bonnell, DW TI Imaging and gasdynamic modeling of pulsed laser film deposition plumes SO OPTICAL ENGINEERING LA English DT Article DE imaging; modeling; pulsed laser deposition; thin films; particulates; emission spectroscopy; gasdynamics ID CHEMISTRY AB Optical multichannel emission spectroscopy and intensified charge-coupled device (ICCD) imaging have been applied to real-time, in situ gas-phase species identification during the pulsed excimer or Nd:YAG laser deposition of various ceramic thin films. A plume gasdynamic expansion model has been developed and used to predict the outer-edge plume front locations for comparison with those observed in the ICCD images. Good agreement was found between the model and ICCD images, with plume temperatures indicated by the model to be typically between 10,000 and 50,000 K. The systems studied include PbZr0.53Ti0.47O3 (PZT), BaTiO3, AIN, and BN. When high laser fluences were used, ICCD imaging also revealed strong evidence for interactions between the laser and the near-surface plume. Plume particulates were also noted at long times following the laser pulse. (C) 1996 Society of Photo-Optical Instrumentation Engineers. RP Schenck, PK (reprint author), NIST,A215 MAT,GAITHERSBURG,MD 20899, USA. NR 16 TC 9 Z9 9 U1 0 U2 1 PU SOC PHOTO-OPT INSTRUM ENG PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 SN 0091-3286 J9 OPT ENG JI Opt. Eng. PD NOV PY 1996 VL 35 IS 11 BP 3199 EP 3205 DI 10.1117/1.601042 PG 7 WC Optics SC Optics GA VT596 UT WOS:A1996VT59600019 ER PT J AU Paulter, NG AF Paulter, NG TI Selecting a short-pulse laser system for photoconductive generation of high-speed electrical pulses SO OPTICAL ENGINEERING LA English DT Article DE photoconductive electrical pulse generation; short-duration electrical pulse; short-pulse laser ID MOLECULAR-BEAM EPITAXY; LOW-TEMPERATURES; GAAS AB The selection of a short-pulse laser is important in electrical pulse metrology applications where the electrical pulses are generated photoconductively, Not only is the duration of the generated electrical pulse important, but so is the peak amplitude of that pulse. Insufficient pulse amplitude may cause excessive uncertainty in measurement results. An approximation is presented that can provide guidelines to selecting the optimal short-pulse laser according to photoconductor, laser, and measurement system characteristics. (C) 1996 Society of Photo-Optical Instrumentation Engineers. RP Paulter, NG (reprint author), NIST,DIV ELECT,GAITHERSBURG,MD 20899, USA. NR 18 TC 0 Z9 0 U1 0 U2 0 PU SOC PHOTO-OPT INSTRUM ENG PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 SN 0091-3286 J9 OPT ENG JI Opt. Eng. PD NOV PY 1996 VL 35 IS 11 BP 3296 EP 3300 DI 10.1117/1.601070 PG 5 WC Optics SC Optics GA VT596 UT WOS:A1996VT59600031 ER PT J AU Guo, J Gallagher, A Cooper, J AF Guo, J Gallagher, A Cooper, J TI Lorentz-Lorenz shift in an inhomogeneously broadened medium SO OPTICS COMMUNICATIONS LA English DT Article ID SELECTIVE REFLECTION SPECTROSCOPY; LOCAL-FIELD; ATOMS AB A simple calculation shows that the Lorentz-Lorenz shift due to the local field correction remains significant in situations where the inhomogeneous broadening of a medium exceeds the homogeneous broadening. As an illustration, the calculated selective reflection signals of a low-density atomic vapor are presented, and it is shown that the Lorentz-Lorenz shift persists in the case where the line width is predominantly determined by the inhomogeneous Doppler width. C1 NATL INST STAND & TECHNOL,BOULDER,CO 80309. RP Guo, J (reprint author), UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. NR 10 TC 8 Z9 8 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0030-4018 J9 OPT COMMUN JI Opt. Commun. PD NOV 1 PY 1996 VL 131 IS 4-6 BP 219 EP 222 DI 10.1016/0030-4018(96)00292-1 PG 4 WC Optics SC Optics GA VN287 UT WOS:A1996VN28700001 ER PT J AU Druzhko, AB Vanderah, DJ Robertson, B Weetall, HH AF Druzhko, AB Vanderah, DJ Robertson, B Weetall, HH TI An azulenic bacteriorhodopsin analog has photoinduced activity SO PHOTOCHEMISTRY AND PHOTOBIOLOGY LA English DT Article ID PIGMENTS; HALOBACTERIA; INTERMEDIATE; MODEL; NMR AB The photoinduced changes of absorbance as well as proton release and uptake have been observed for an azulenic analog of wild-type bacteriorhodopsin. The release and uptake of protons have been measured using a highly sensitive electrochemical technique. Bacteriorhodopsin membrane patches on a tin-oxide electrode produce a transient photocurrent that is negative for proton release and positive for proton uptake. For azulenic bacteriorhodopsin the photocurrent is approximately 20% of the transient observed with native bacteriorhodopsin. The existence of the photoinduced absorbance changes and the transient photocurrent are important results for gaining further insight into the photoinduced function of bacteriorhodopsin. C1 NIST,DIV BIOTECHNOL,GAITHERSBURG,MD 20899. NR 14 TC 6 Z9 6 U1 1 U2 2 PU AMER SOC PHOTOBIOLOGY PI AUGUSTA PA BIOTECH PARK, 1021 15TH ST, SUITE 9, AUGUSTA, GA 30901-3158 SN 0031-8655 J9 PHOTOCHEM PHOTOBIOL JI Photochem. Photobiol. PD NOV PY 1996 VL 64 IS 5 BP 867 EP 869 DI 10.1111/j.1751-1097.1996.tb01849.x PG 3 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA VT662 UT WOS:A1996VT66200023 ER PT J AU Deprit, A Lanchares, V Inarrea, M Salas, JP Sierra, JD AF Deprit, A Lanchares, V Inarrea, M Salas, JP Sierra, JD TI Teardrop bifurcation for Rydberg atoms in parallel electric and magnetic fields SO PHYSICAL REVIEW A LA English DT Article ID SYSTEMS AB In the classical model for Rydberg atoms, the transition from a pure Zeeman effect to a pure Stark effect passes through a teardrop bifurcation when the magnetic quantum number is not zero. C1 UNIV LA RIOJA, DEPT MATEMAT & COMPUTAC, LOGRONO 26004, SPAIN. UNIV LA RIOJA, DEPT FIS, LOGRONO 26004, SPAIN. RP Deprit, A (reprint author), NIST, GAITHERSBURG, MD 20899 USA. RI Lanchares, Victor/B-4688-2010; Sierra Murillo, Jose Daniel/I-3281-2015; OI Lanchares, Victor/0000-0003-3228-9382; Sierra Murillo, Jose Daniel/0000-0001-5359-420X; Inarrea Las Heras, Manuel/0000-0003-2859-1116; Salas, J. Pablo/0000-0003-2009-8247 NR 32 TC 15 Z9 15 U1 0 U2 4 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD NOV PY 1996 VL 54 IS 5 BP 3885 EP 3893 DI 10.1103/PhysRevA.54.3885 PG 9 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA VT673 UT WOS:A1996VT67300029 ER PT J AU Ruprecht, PA Edwards, M Burnett, K Clark, CW AF Ruprecht, PA Edwards, M Burnett, K Clark, CW TI Probing the linear and nonlinear excitations of Bose-condensed neutral atoms in a trap SO PHYSICAL REVIEW A LA English DT Article ID EINSTEIN CONDENSATION; SCHRODINGER-EQUATION; GAS; OPTICS; FIELD AB We investigate the response of a Bose-Einstein condensate of trapped, neutral atoms to weak and strong sinusoidal perturbation of the crapping potential both by solving the Bogoliubov equations and by direct integration of the time-dependent, driven Ginzburg-Pitaevskii-Gross equation. We find that the distortion of the condensate is maximal when the frequency of the perturbation equals one of the mode positions of the condensate's excitation spectrum. On resonance, the condensate exhibits a strong nonlinear response that can be Used as a clear signature of the mode frequency in an experiment where the trap potential is weakly perturbed. For strong driving, we find evidence for an array of nonlinear effects such as harmonic generation and frequency mixing. These phenomena are the matter-wave analogs of conventional nonlinear optics and should be straightforward to study in evaporatively cooled samples of alkali-metal atoms. C1 GEORGIA SO COLL,DEPT PHYS,STATESBORO,GA 30460. NATL INST STAND & TECHNOL,PHYS LAB,DIV ELECTRON & OPT PHYS,GAITHERSBURG,MD 20899. RP Ruprecht, PA (reprint author), UNIV OXFORD,DEPT PHYS,CLARENDON LAB,OXFORD OX1 3PU,ENGLAND. RI Clark, Charles/A-8594-2009 OI Clark, Charles/0000-0001-8724-9885 NR 30 TC 109 Z9 113 U1 0 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD NOV PY 1996 VL 54 IS 5 BP 4178 EP 4187 DI 10.1103/PhysRevA.54.4178 PG 10 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA VT673 UT WOS:A1996VT67300062 ER PT J AU Yildirim, T Barbedette, L Fischer, JE Bendele, GM Stephens, PW Lin, CL Goze, C Rachdi, F Robert, J Petit, P Palstra, TTM AF Yildirim, T Barbedette, L Fischer, JE Bendele, GM Stephens, PW Lin, CL Goze, C Rachdi, F Robert, J Petit, P Palstra, TTM TI Synthesis and properties of mixed alkali-metal-alkaline-earth fullerides SO PHYSICAL REVIEW B LA English DT Article ID FULLERENE SUPERCONDUCTORS; ELECTRONIC-STRUCTURE; K3C60; LATTICE; TRANSITION; C-60 AB A new class of fullerides, MBa(2)C(60) (M=K, Rb, or Cs) and MBaCsC(60), allows us to study the effect of molecular valence on electronic structure while maintaining the crystal structure of M(3)C(60) superconductors. X-ray diffraction and Raman scattering show that these are face-centered cubic with pentavalent and quadrivalent C-60's, respectively. We find no evidence for superconductivity down to 0.5 K, while electron spin resonance indicates weakly metallic behavior. C-13 NMR indicates strong dynamical disorder above room temperature, which may be related to the anisotropic crystal field induced by cations of different valence. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. UNIV PENN,DEPT MAT SCI,PHILADELPHIA,PA 19104. UNIV PENN,RES STRUCT MATTER LAB,PHILADELPHIA,PA 19104. SUNY STONY BROOK,DEPT PHYS,STONY BROOK,NY 11794. TEMPLE UNIV,DEPT PHYS,PHILADELPHIA,PA 19122. UNIV MONTPELLIER 2,DYNAM PHASES CONDENSEES GRP,F-34060 MONTPELLIER,FRANCE. ULP,INST CHARLES SADRON,CNRS,F-67000 STRASBOURG,FRANCE. AT&T BELL LABS,MURRAY HILL,NJ 07974. RP Yildirim, T (reprint author), UNIV MARYLAND,COLLEGE PK,MD 20742, USA. RI yildirim, taner/A-1290-2009; Palstra, Thomas/K-1961-2013 OI Palstra, Thomas/0000-0001-5239-3115 NR 30 TC 16 Z9 16 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD NOV 1 PY 1996 VL 54 IS 17 BP 11981 EP 11984 DI 10.1103/PhysRevB.54.11981 PG 4 WC Physics, Condensed Matter SC Physics GA VT681 UT WOS:A1996VT68100037 ER PT J AU Rao, MVVS VanBrunt, RJ Olthoff, JK AF Rao, MVVS VanBrunt, RJ Olthoff, JK TI Resonant charge exchange and the transport of ions at high electric-field to gas-density ratios (E/N) in argon, neon, and helium SO PHYSICAL REVIEW E LA English DT Article ID KINETIC-ENERGY DISTRIBUTIONS; PARALLEL-PLANE ELECTRODES; CROSS-SECTIONS; VELOCITY DISTRIBUTIONS; REFERENCE CELL; POSITIVE-IONS; DISCHARGES; AR; OSCILLATIONS; INSTRUMENT AB Translational kinetic-energy distributions of singly and doubly charged ions have been measured at high electric-field to gas-density ratios (E/N) up to 5.0 x 10(-17) V m(2) (50 kTd) in diffuse, parallel-plate Townsend discharges in Ar, Ne, and He using an ion energy analyzer-mass spectrometer. For Ar+ in Ar and Ne+ in Ne when E/N < 2.0 x 10(-17) V m(2) and for He+ in He when E/N < 1.0 x 10(-17) V m(2), the energy distributions are Maxwellian and consistent with predictions based on the assumption that resonant symmetric charge exchange is the dominant ion-neutral-species collision process. At higher E/N values, the kinetic-energy distributions for Ar+, Ne+, and He+ show departures from the Maxwellian form that are indicative of deviations from the charge-transfer model. The mean ion energies (effective ion temperatures) ale consistent in the low E/N range with the available drift-velocity data, and in the case of Ar+ with recent results of Radovanov et al. [Phys. Rev. E 51, 6036 (1995)] from Townsend discharge experiments. The charge-exchange cross sections derived from Maxwellian fits to the energy distribution data for Ar+ + Ar, Ne+ + Ne, and He+ + He agree with available data. The relative contributions of the doubly charged ions Ar2+, Ne2+, and He2+ to the total ion flux were found to be small (less than 3%) and tend to decrease initially with increasing E/N. The mean energies of the doubly charged ions are higher than those for the corresponding singly charged ions, and the results suggest that double charge transfer could be the dominant process affecting the transport of Ar2+ and Ne2+ for E/N below about 1.5 x 10(-17) V m(2). The observed He2+ kinetic-energy distributions are not consistent with a charge-transfer model. C1 INST PLASMA RES, GANDHI SAGAR 382424, INDIA. RP NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. NR 67 TC 49 Z9 49 U1 0 U2 7 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0045 EI 2470-0053 J9 PHYS REV E JI Phys. Rev. E PD NOV PY 1996 VL 54 IS 5 BP 5641 EP 5656 DI 10.1103/PhysRevE.54.5641 PG 16 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA VU537 UT WOS:A1996VU53700142 ER PT J AU Hill, RJ AF Hill, RJ TI Pressure-velocity-velocity statistics in isotropic turbulence SO PHYSICS OF FLUIDS LA English DT Article ID SPECTRA AB Relationships are derived between pressure-velocity-velocity (PVV) statistics, fourth-order velocity structure functions, and the pressure structure function. The PVV statistics are related to the correlation of pressure at one point with the product of two velocity components at another point. The Navier-Stokes equation, isotropy, and incompressibility are used; no other assumption is used. Thus the relationships apply for all Reynolds numbers and can be used as a benchmark to determine how well turbulence models mimic pressure fluctuations in Navier-Stokes turbulence. A necessary condition limiting compressibility is given. The inertial-range and viscous-range formulas of the PVV statistics are obtained. The results are compared with previous theories that used the joint Gaussian approximation. Data from grid turbulence are used to evaluate the statistics. RP Hill, RJ (reprint author), NOAA,ENVIRONM RES LABS,ENVIRONM TECHNOL LAB,BOULDER,CO 80303, USA. NR 21 TC 5 Z9 5 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-6631 J9 PHYS FLUIDS JI Phys. Fluids PD NOV PY 1996 VL 8 IS 11 BP 3085 EP 3093 DI 10.1063/1.869082 PG 9 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA VP367 UT WOS:A1996VP36700025 ER PT J AU Monroe, C Wineland, D AF Monroe, C Wineland, D TI Future of quantum computing proves to be debatable SO PHYSICS TODAY LA English DT Letter RP Monroe, C (reprint author), UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,325 BROADWAY,BOULDER,CO 80309, USA. RI Monroe, Christopher/G-8105-2011 NR 5 TC 4 Z9 4 U1 1 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0031-9228 J9 PHYS TODAY JI Phys. Today PD NOV PY 1996 VL 49 IS 11 BP 107 EP 108 DI 10.1063/1.881538 PG 2 WC Physics, Multidisciplinary SC Physics GA VQ892 UT WOS:A1996VQ89200029 ER PT J AU Voronovich, AG AF Voronovich, AG TI On the theory of electromagnetic waves scattering from the sea surface at low grazing angles SO RADIO SCIENCE LA English DT Article ID MODEL AB Scattering of electromagnetic (EM) waves from the sea surface is usually considered with the help of a two-scale (composite surface) model. It is shown theoretically that for broad wavelength range at grazing angles less than about 20 degrees, diffraction of the incident field on large-scale (undulating) components cannot be considered using the tangent plane (Kirchhoff) approximation. In other words, an undulating surface cannot be treated as a set of locally plane facets, and its curvature becomes an important parameter. The effects of curvature of the undulating surface are estimated for a two-dimensional situation. It is shown that in this case, backscattering cross sections at low grazing angles are proportional to the sin(2) alpha rather than to the sin(4) alpha (which would be the case according to Rice's classical formulae). This corresponds to experimental results. The theoretical curve of the sigma(HH)/sigma(VV) ratio fits well the experimental data published by Lee et nl. [1995] (for ''slow'' signals). C1 NOAA,ENVIRONM TECHNOL LAB,BOULDER,CO. UNIV COLORADO,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. NR 15 TC 23 Z9 24 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0048-6604 J9 RADIO SCI JI Radio Sci. PD NOV-DEC PY 1996 VL 31 IS 6 BP 1519 EP 1530 DI 10.1029/96RS02250 PG 12 WC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Remote Sensing; Telecommunications SC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Remote Sensing; Telecommunications GA VW106 UT WOS:A1996VW10600017 ER PT J AU Lataitis, RJ Clifford, SF AF Lataitis, RJ Clifford, SF TI Effect of atmospheric turbulence on the spot size of a radio-acoustic sounding system: A calculation revisited SO RADIO SCIENCE LA English DT Article AB A theory developed almost 20 years ago suggests that atmospheric turbulence does not significantly alter the average spot size of the radar return from a radio acoustic sounding system (RASS). This theory predicts that the primary effect of turbulence is a reduction of the on-axis intensity and the formation of extended tails in the spot profile, with little or no broadening of the central core of the spot. For a narrow-beam radar, the width of the central core was found to be proportional to the diameter of the radar transmitting antenna. We demonstrate that this conclusion is based on an erroneous numerical evaluation of a fourfold integral that rigorously describes the spot profile. We use an alternate formulation to show that the spot profile can be expressed as a convolution of the radar antenna illumination function and a function whose width depends on the strength of turbulence. This convolution is governed by the ratio W/rho(0), where W is the horizontal dimension of the radar beam and rho(0) is the characteristic transverse scale of the turbulence-induced acoustic wavefront distortions, both evaluated at the range R of interest. In weak turbulence (i.e., when W much less than rho(0)) the spot profile approximates the antenna illumination function. In strong turbulence (i.e., when rho(0) much less than W) the spot profile is significantly broadened and has a diameter proportional to lambda R/rho(0), where lambda is the radar wavelength. The spot broadening is consistent with recent theoretical and experimental work. The approximate spot profile as a function of turbulence strength for a variety of circularly symmetric antenna illumination functions is examined. RP Lataitis, RJ (reprint author), US DEPT COMMERCE,NOAA,ERL,ENVIRONM TECHNOL LAB,325 BROADWAY,BOULDER,CO 80303, USA. NR 16 TC 3 Z9 3 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0048-6604 J9 RADIO SCI JI Radio Sci. PD NOV-DEC PY 1996 VL 31 IS 6 BP 1531 EP 1540 DI 10.1029/96RS02631 PG 10 WC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Remote Sensing; Telecommunications SC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Remote Sensing; Telecommunications GA VW106 UT WOS:A1996VW10600018 ER PT J AU Fogarty, MJ Mayo, RK OBrien, L Serchuk, FM Rosenberg, AA AF Fogarty, MJ Mayo, RK OBrien, L Serchuk, FM Rosenberg, AA TI Assessing uncertainty and risk in exploited marine populations SO RELIABILITY ENGINEERING & SYSTEM SAFETY LA English DT Article ID STOCK ASSESSMENT; RECRUITMENT; FISHERIES; MANAGEMENT; TRENDS AB The assessment and management of exploited fish and invertebrate populations is subject to several types of uncertainty. This uncertainty translates into risk to the population in the development and implementation of fishery management advice. Here, we define risk as the probability that exploitation rates will exceed a threshold level where long term sustainability of the stock is threatened. We distinguish among several sources of error or uncertainty due to (a) stochasticity in demographic rates and processes, particularly in survival rates during the early life stages; (b) measurement error resulting from sampling variation in the determination of population parameters or in model estimation; and (c) the lack of complete information on population and ecosystem dynamics. The first represents a form of aleatory uncertainty while the latter two factors represent forms of epistemic uncertainty. To illustrate these points, we evaluate the recent status of the Georges Bank cod stock in a risk assessment framework. Short term stochastic projections are made accounting for uncertainty in population size and for random variability in the number of young surviving to enter the fishery. We show that recent declines in this cod stock can be attributed to exploitation rates that have substantially exceeded sustainable levels. Published by Elsevier Science Limited. C1 NATL MARINE FISHERIES SERV,NATL OCEAN & ATMOSPHER ADM,GLOUCESTER,MA 01930. RP Fogarty, MJ (reprint author), NOAA,NATL MARINE FISHERIES SERV,NE FISHERIES SCI CTR,WOODS HOLE,MA 02543, USA. NR 37 TC 13 Z9 13 U1 1 U2 8 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0951-8320 J9 RELIAB ENG SYST SAFE JI Reliab. Eng. Syst. Saf. PD NOV-DEC PY 1996 VL 54 IS 2-3 BP 183 EP 195 DI 10.1016/S0951-8320(96)00074-9 PG 13 WC Engineering, Industrial; Operations Research & Management Science SC Engineering; Operations Research & Management Science GA WB789 UT WOS:A1996WB78900009 ER PT J AU Kim, S Yu, JW Han, CC AF Kim, S Yu, JW Han, CC TI Shear light scattering photometer with optical microscope for the study of polymer blends SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID ENHANCED CONCENTRATION FLUCTUATIONS; PHASE-SEPARATION; FLOW; BEHAVIOR; MIXTURES; PATTERN; RATES AB A shear light scattering: photometer with an optical microscope was constructed for the study of polymer blends in a simple shear held. This instrument utilizes a cone and plate or parallel plate geometry for the generation of shear field. The shear rates are controlled by a microstepping motor. The controllable range of shear rate is between 0.002 and 1000 s(-1). The bottom plate of the shear cell has a special design to accommodate the microscope objective and a thin disk-typo heater for temperature control. The accessible q range is from 0.7 to 4.6 mu m(-1) with a 632.8 nm He-Ne laser or from 0.9 to 6.0 mu m(-1) with a 488 nm Ar ion laser. The temperature can be controlled from ambient temperature to 250 degrees C with +/- 0.1 degrees C accuracy. A phase contrast microscope and a fluorescence microscope are built into this photometer for the in situ morphological study of materials of interest. The optics for light scattering and microscopy can be switched back and forth by a simple translational movement of a rail-mounted optical platform, without any realignment, for comparison of data from reciprocal space with that from real space. A bulk polystyrene/polybutadiene blend and a polystyrene/polybutadiene/dioctylphthalate blend were used to demonstrate the performance and versatility of this instrument. RP Kim, S (reprint author), NATL INST STAND & TECHNOL,DIV POLYMERS,GAITHERSBURG,MD 20899, USA. NR 28 TC 34 Z9 34 U1 1 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD NOV PY 1996 VL 67 IS 11 BP 3940 EP 3947 DI 10.1063/1.1147295 PG 8 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA VT188 UT WOS:A1996VT18800022 ER PT J AU Watari, S Detman, T Joselyn, JA AF Watari, S Detman, T Joselyn, JA TI A large arcade along the inversion line, observed on May 19, 1992 by Yohkoh, and enhancement of interplanetary energetic particles SO SOLAR PHYSICS LA English DT Article ID DISAPPEARING SOLAR FILAMENTS; CORONAL MASS EJECTIONS; X-RAY TELESCOPE; FLARE MYTH; H-ALPHA; EVOLUTION; STREAMER; PROMINENCES; ERUPTION; EVENTS AB A large arcade associated with a long-duration soft X-ray emission was observed on May 19, 1992 by the Yohkoh soft X-ray telescope. This large arcade was formed along the inversion line and a filament eruption was observed as part of this event. Also associated with this event were solar energetic particles and an interplanetary shock observed near Earth. This event supports the idea that coronal mass ejections are large-scale eruptions along an inversion line, or a heliospheric current sheet. However, this event implies that present models on eruptions are not sufficient. C1 NOAA, SPACE ENVIRONM CTR, BOULDER, CO 80303 USA. RP COMMUN RES LABS, 4-2-1 NAKUIKITA, KOGANEI, TOKYO 184, JAPAN. NR 48 TC 8 Z9 8 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-0938 EI 1573-093X J9 SOL PHYS JI Sol. Phys. PD NOV PY 1996 VL 169 IS 1 BP 167 EP 179 DI 10.1007/BF00153839 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VY869 UT WOS:A1996VY86900010 ER PT J AU Slade, RCT Hall, GP Ramanan, A Prince, E AF Slade, RCT Hall, GP Ramanan, A Prince, E TI Structure and proton conduction in pyrochlore-type antimonic acid: A neutron diffraction study SO SOLID STATE IONICS LA English DT Article DE neutron diffraction; antimonic acid; proton conductor ID CRYSTALLINE AB The structure of pyrochlore-type antimonic acid, HSbO3 . 0.5H(2)O, has been investigated using powder diffraction of neutrons. The structure (space group ) contains an [Sb2O62-] framework, with interstitial oxygens present as a mixture of H2O and H3O+. Three H-atom sites have been identified, (1) close to the [Sb2O62-] framework in hydroxyl groups (Sb-OH), (2)H in water molecules H-bonded to framework hydroxyls, and (3)H in H3O+ ions H-bonded to O-atoms of the intercavity windows. An intraframework equilibrium of the type Sb-OH + H2O reversible arrow Sb-O- + H3O+ provides the mechanism for intracavity chemical exchange and proton conduction. C1 NATL INST STAND & TECHNOL, DIV REACTOR RADIAT, GAITHERSBURG, MD 20899 USA. UNIV MARYLAND, DEPT MAT & NUCL ENGN, COLLEGE PK, MD 20742 USA. RP Slade, RCT (reprint author), UNIV EXETER, DEPT CHEM, STOCKER RD, EXETER EX4 4QD, DEVON, ENGLAND. NR 16 TC 18 Z9 18 U1 1 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2738 EI 1872-7689 J9 SOLID STATE IONICS JI Solid State Ion. PD NOV PY 1996 VL 92 IS 3-4 BP 171 EP 181 DI 10.1016/S0167-2738(96)00497-3 PG 11 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA WB191 UT WOS:A1996WB19100002 ER PT J AU Liao, CT Iyer, HK Vecchia, DF AF Liao, CT Iyer, HK Vecchia, DF TI Construction of orthogonal two-level designs of user-specified resolution where N not equal 2(k) SO TECHNOMETRICS LA English DT Article DE fractional factorial designs; linear graphs; parallel-flats designs; screening experiments; single-flat designs AB Fractional two-level factorial designs are often used in the early stages of an investigation to screen for important factors. Traditionally, 2(n-k) fractional factorial designs of resolution III, IV, or V have been used for this purpose. When the investigator is able to specify the set of nonnegligible factorial effects, it is sometimes possible to obtain an orthogonal design with fewer runs than a standard textbook design by searching within a wider class of designs called parallel-flats designs. The run sizes in this class of designs do not necessarily need to be powers of 2. We discuss an algorithm for constructing orthogonal parallel-flats designs to meet user specifications. Several examples illustrate the use of the algorithm. C1 NATL INST STAND & TECHNOL,BOULDER,CO 80303. COLORADO STATE UNIV,DEPT STAT,FT COLLINS,CO 80523. RP Liao, CT (reprint author), CHAOYANG INST TECHNOL,DEPT FINANCE,WUFENG,TAICHUNG,TAIWAN. OI Liao, Chen-Tuo/0000-0001-9777-3701 NR 20 TC 10 Z9 10 U1 0 U2 0 PU AMER STATIST ASSN PI ALEXANDRIA PA 1429 DUKE ST, ALEXANDRIA, VA 22314 SN 0040-1706 J9 TECHNOMETRICS JI Technometrics PD NOV PY 1996 VL 38 IS 4 BP 342 EP 353 DI 10.2307/1271305 PG 12 WC Statistics & Probability SC Mathematics GA VP434 UT WOS:A1996VP43400009 ER PT J AU Cailliet, GM Botsford, LW Brittnacher, JG Ford, G Matsubayashi, M King, A Watters, DL Kope, RG AF Cailliet, GM Botsford, LW Brittnacher, JG Ford, G Matsubayashi, M King, A Watters, DL Kope, RG TI Development of a computer-aided age determination system: Evaluation based on otoliths of bank rockfish off California SO TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY LA English DT Article ID LONGEVITY; SEBASTES; MORTALITY; GROWTH AB We have developed a computer-aided system (Bony Parts) to analyze periodic bands in fish otoliths (or other structures) for age estimation. The image analysis program first scans the image of a thin otolith section, perpendicular to the bands specified by the user. Adjacent scans are averaged and filtered with Fourier transformation or spatial domain convolution. Bands of higher density are detected and are marked and summed on the screen. We evaluated this new technique using subsamples of thin-sectioned otoliths from the bank rockfish Sebastes rufus. The time and effort for cleaning, preparation, sectioning, and mounting are the same for both traditional and computer-aided techniques. The computer-aided technique reduced the time and tedium of counting bands, yet still allowed the user to interactively make subjective decisions about aging criteria. Both approaches produced similar readings, but computer-aided estimates were more precise than traditional readings and required less analysis time. Thus, this new technique allows sample size and precision to be increased for a given amount of effort. Use of this new technique to age 1,897 sections produced von Bertalanffy growth equations that indicate female bank rockfish grow to a larger theoretical maximum size than males (L(x) = 500.7 mm versus 438.1 mm total length) but grow at a slightly slower rate (K = 0.054 for females versus 0.073 for males). C1 UNIV CALIF DAVIS,CTR IMAGE PROC & INTEGRATED COMPUTING,DAVIS,CA 95616. MONTEREY BAY NATL MARINE SANCTUARY,MONTEREY,CA 93940. CALIF DEPT FISH & GAME,MENLO PK,CA 94025. UNIV CALIF DAVIS,DEPT WILDLIFE FIS & CONSERVAT BIOL,DAVIS,CA 95616. RP Cailliet, GM (reprint author), MOSS LANDING MARINE LABS,POB 450,MOSS LANDING,CA 95039, USA. NR 35 TC 12 Z9 12 U1 1 U2 1 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE SUITE 110, BETHESDA, MD 20814-2199 SN 0002-8487 J9 T AM FISH SOC JI Trans. Am. Fish. Soc. PD NOV PY 1996 VL 125 IS 6 BP 874 EP 888 DI 10.1577/1548-8659(1996)125<0874:DOACAA>2.3.CO;2 PG 15 WC Fisheries SC Fisheries GA VV462 UT WOS:A1996VV46200006 ER PT J AU Hobbie, EK Merkle, G Bauer, BJ Han, CC AF Hobbie, EK Merkle, G Bauer, BJ Han, CC TI Spinodal decomposition in hydrogen-bonded polymer blends SO MODERN PHYSICS LETTERS B LA English DT Review ID THERMODYNAMICS; BEHAVIOR AB Time-resolved small-angle neutron-scattering (SANS) studies of spinodal decomposition in hydrogen-bonded blends of polystyrene and poly(butylmethacrylate) reveal extremely slow kinetics of phase separation in the vicinity of the critical point. The experimental data are interpreted within the context of a mean-field model that predicts energetic barriers to extended composition fluctuations. The scenario bears a resemblance to dynamic critical phenomena in Ising systems with coupling to a set of mobile impurities. RP Hobbie, EK (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. RI Hobbie, Erik/C-8269-2013 NR 16 TC 2 Z9 2 U1 1 U2 5 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 9128, SINGAPORE SN 0217-9849 J9 MOD PHYS LETT B JI Mod. Phys. Lett. B PD OCT 30 PY 1996 VL 10 IS 25 BP 1219 EP 1226 DI 10.1142/S0217984996001383 PG 8 WC Physics, Applied; Physics, Condensed Matter; Physics, Mathematical SC Physics GA VY276 UT WOS:A1996VY27600001 ER PT J AU Li, HQ Ono, RH Vale, LR Rudman, DA Liou, SH AF Li, HQ Ono, RH Vale, LR Rudman, DA Liou, SH TI A novel multilayer circuit process using YBa2Cu3Ox/SrTiO3 thin films patterned by wet etching and ion milling SO APPLIED PHYSICS LETTERS LA English DT Article ID YBA2CU3O7 FILMS; MAGNETOMETERS AB A process combining hydrofluoric acid (HF) and Ar+ ion milling has been used to make YBa2Cu3Ox/SrTiO3/YBa2Cu3Ox(YBCO/STO/YBCO multilayer test circuits. Low-angle steps can be readily etched in STO and YBCO films with this process. YBCO lines crossing 5 degrees steps have about the same critical temperature T-c (89-99 K) and critical current density J(c) (>1x10(6) A/cm(2) at 86 K) as lines on planar surfaces. Via connections have the same T-c as other circuit components and adequate critical currents for most circuit designs. (C) 1996 American Institute of Physics. C1 UNIV NEBRASKA,DEPT PHYS,LINCOLN,NE 68588. RP Li, HQ (reprint author), NIST,BOULDER,CO 80303, USA. NR 12 TC 8 Z9 8 U1 2 U2 7 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD OCT 28 PY 1996 VL 69 IS 18 BP 2752 EP 2754 DI 10.1063/1.117700 PG 3 WC Physics, Applied SC Physics GA VP265 UT WOS:A1996VP26500044 ER PT J AU Balsara, NP Lin, C Hammouda, B AF Balsara, NP Lin, C Hammouda, B TI Early stages of nucleation and growth in a polymer blend SO PHYSICAL REVIEW LETTERS LA English DT Article ID PHASE; COPOLYMER; KINETICS AB The early stages of nucleation and growth in a mixture of high polymers were studied by time-resolved neutron scattering. During the first 160 min, a slow clustering was evident, indicating a buildup of concentration fluctuations. The clusters formed at the end of this stage had the characteristics of ''critical nuclei,'' because phase separation proceeded rapidly after their formation. At this stage, the scattering profiles showed a peak at finite wave vectors (q(max)). The scaling exponents for the time dependence of the peak intensity and q(max) are inconsistent with current theories. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP Balsara, NP (reprint author), POLYTECH INST NEW YORK,DEPT CHEM ENGN,6 METROTECH CTR,BROOKLYN,NY 11201, USA. NR 15 TC 43 Z9 43 U1 0 U2 23 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 28 PY 1996 VL 77 IS 18 BP 3847 EP 3850 DI 10.1103/PhysRevLett.77.3847 PG 4 WC Physics, Multidisciplinary SC Physics GA VP225 UT WOS:A1996VP22500039 ER PT J AU Yarosh, ES Ropelewski, CF Mitchell, KE AF Yarosh, ES Ropelewski, CF Mitchell, KE TI Comparisons of humidity observations and Eta model analyses and forecasts for water balance studies SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article AB Direct comparison was performed between observed radiosonde humidity and vapor transport profiles and the National Centers for Environmental Prediction (NCEP) (formerly the National Meteorological Center) mesoscale Eta model analyses and forecasts. The data for this comparison were gathered during the Global Energy and Water Cycle Experiment's Continental-Scale International Project Integrated Systems Test (GIST) for the period July 15 to August 31, 1994, which fell within the preoperational evaluation phase of the new NCEP mesoscale Eta model and associated data assimilation system. These intercomparisons show good agreement between Eta model analyses and observations in humidity and the zonal and meridional components of the humidity transport. Typical root-mean-square (RMS) errors relative to observed standard deviations were of the order of 0.4-0.5 at all levels between the surface and 300 hPa. The relative RMS humidity errors associated with the forecasts ranged between 0.9 and 1.4 in the lowest 300 hPa for all forecast times examined (3 to 36 hours). The RMS humidity transport errors for the forecasts tend to be somewhat less. During the GIST period, this study found the Eta model performance for water balance studies to be somewhat degraded over mountainous terrain. On the basis of this GIST finding and other corroborating evidence, NCEP corrected an error in the Eta model data assimilation system. The Eta-model- derived, vertically integrated moisture flux divergence compares favorably with similar estimates based on radiosonde observations alone. In these comparisons, the Eta model estimates of evaporation minus precipitation agree with the radiosonde estimates within 10% of the mean precipitation over the Mississippi River Basin. The agreement is less (around 50% of the mean precipitation) for a smaller basin. The analysis suggests that the Eta model forecasts may be useful over larger basins for various water budget study issues, such as diurnal variability and impacts of observation sampling density. C1 NOAA, NATL CTR ENVIRONM PROTECT, CLIMATE PREDICT CTR, WASHINGTON, DC 20233 USA. NOAA, NATL CTR ENVIRONM PROTECT, ENVIRONM MODELING CTR, WASHINGTON, DC 20233 USA. RP Yarosh, ES (reprint author), RES & DATA SYST CORP, 7833 WALKER DR, SUITE 550, GREENBELT, MD 20770 USA. NR 7 TC 8 Z9 8 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD OCT 27 PY 1996 VL 101 IS D18 BP 23289 EP 23298 DI 10.1029/96JD02196 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VP976 UT WOS:A1996VP97600002 ER PT J AU Alexander, MJ Rosenlof, KH AF Alexander, MJ Rosenlof, KH TI Nonstationary gravity wave forcing of the stratospheric zonal mean wind SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID GENERAL-CIRCULATION MODEL; MIDDLE ATMOSPHERE; SEMIANNUAL OSCILLATION; MOMENTUM FLUXES; WINTER STRATOSPHERE; LOWER THERMOSPHERE; DOWNWARD CONTROL; DRAG; MESOSPHERE; SIMULATION AB The role of gravity wave forcing in the zonal mean circulation of the stratosphere is discussed. Starting from some very simple assumptions about the momentum flux spectrum of nonstationary (non-zero phase speed) waves at forcing levels in the troposphere, a linear model is used to calculate wave propagation through climatological zonal mean winds at solstice seasons. As the wave amplitudes exceed their stable limits, a saturation criterion is imposed to account for nonlinear wave breakdown effects, and the resulting vertical gradient in the wave momentum flux is then used to estimate the mean flow forcing per unit mass. Evidence from global, assimilated data sets are used to constrain these forcing estimates. The results suggest the gravity-wave-driven force is accelerative (has the same sign as the mean wind) throughout most of the stratosphere above 20 km. The sense of the gravity wave forcing in the stratosphere is thus opposite to that in the mesosphere, where gravity wave drag is widely believed to play a principal role in decelerating the mesospheric jets. The forcing estimates are further compared to existing gravity wave parameterizations for the same climatological zonal mean conditions. Substantial disagreement is evident in the stratosphere, and we discuss the reasons for the disagreement. The results suggest limits on typical gravity wave amplitudes near source levels in the troposphere at solstice seasons. The gravity wave forcing in the stratosphere appears to have a substantial effect on lower stratospheric temperatures during southern hemisphere summer and thus may be relevant to climate. C1 UNIV COLORADO, NOAA, COOPERAT INST RES ENVIRONM SCI, BOULDER, CO 80309 USA. RP Alexander, MJ (reprint author), UNIV WASHINGTON, DEPT ATMOSPHER SCI, BOX 351640, SEATTLE, WA 98195 USA. RI Rosenlof, Karen/B-5652-2008 OI Rosenlof, Karen/0000-0002-0903-8270 NR 43 TC 61 Z9 61 U1 1 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD OCT 27 PY 1996 VL 101 IS D18 BP 23465 EP 23474 DI 10.1029/96JD02197 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VP976 UT WOS:A1996VP97600016 ER PT J AU Rust, WD Marshall, TC AF Rust, WD Marshall, TC TI On abandoning the thunderstorm tripole-charge paradigm SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID MESOSCALE CONVECTIVE SYSTEM; KINEMATIC STRUCTURE; ELECTRIC-FIELD; REGION AB We reexamine the original, half-century-old, in situ measurements of Simpson and colleagues used to justify the tripole model of charge structure of a thunderstorm that became the paradigm for the charge structure of mature thunderstorms. We find that the original measurements violate the criteria of the tripole model in 49% of the cases. We also reexamine our soundings of electric field in thunderstorms and mesoscale convective systems in the same way as the original soundings were. Our soundings do not fit the tripole model in at least 86% of the storms. Even when we consider only the major features in the electric field profiles, our data show noncompliance with the tripole model in 45% of the cases. We conclude that we must abandon the paradigm of the tripole-charge structure of thunderstorms. C1 UNIV MISSISSIPPI, DEPT PHYS & ASTRON, UNIVERSITY, MS 38677 USA. RP Rust, WD (reprint author), NATL SEVERE STORMS LAB, 1313 HALLEY CIRCLE, NORMAN, OK 73069 USA. NR 11 TC 29 Z9 32 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD OCT 27 PY 1996 VL 101 IS D18 BP 23499 EP 23504 DI 10.1029/96JD01802 PG 6 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VP976 UT WOS:A1996VP97600019 ER PT J AU Williams, RM Papanikolas, JM Rathje, J Leone, SR AF Williams, RM Papanikolas, JM Rathje, J Leone, SR TI Quantum-state-resolved 2-level femtosecond rotational coherence spectroscopy: Determination of rotational constants at medium and high J in Li-2, a simple diatomic system SO CHEMICAL PHYSICS LETTERS LA English DT Article ID SUB-DOPPLER SPECTROSCOPY; LARGE MOLECULES; GROUND-STATE; DYNAMICS; IODINE AB A series of rotational wave packet recurrences originating from single 2-level coherent rotational superpositions are observed in the E((1) Sigma(g)(+)) state of Li-2. The rotational wave packet is created by ultrafast laser excitation from a specific re-vibrational level in the A((1) Sigma(u)(+)) state selected by cw laser excitation. Using this technique the rotational constant and the centrifugal distortion constant are determined for high J levels of the upsilon=9 vibrational level in the E((1) Sigma(g)(+)) state. This technique is discussed vis-a-vis traditional forms of ultrafast rotational coherence spectroscopy where information primarily at low J is obtained. C1 UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. RP Williams, RM (reprint author), NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. NR 19 TC 11 Z9 11 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD OCT 25 PY 1996 VL 261 IS 4-5 BP 405 EP 413 DI 10.1016/0009-2614(96)00979-7 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VP354 UT WOS:A1996VP35400003 ER PT J AU Rudich, Y Talukdar, RK Imamura, T Fox, RW Ravishankara, AR AF Rudich, Y Talukdar, RK Imamura, T Fox, RW Ravishankara, AR TI Uptake of NO3 on KI solutions: Rate coefficient for the NO3+I- reaction and gas-phase diffusion coefficients for NO3 SO CHEMICAL PHYSICS LETTERS LA English DT Article ID RATE CONSTANTS; CHEMISTRY; RADICALS; KINETICS; SURFACES; CLOUD; WATER; TUBES AB Uptake of NO3 by KI solutions was measured at 273+/-1 K using a wetted-wall flow tube to determine the rate coefficient for the NO3(aq)+I- reaction to be k=(4.6+/-0.5)x10(9) M(-1) s(-1). It is suggested that the reaction of NO3 with halide ions proceeds by electron transfer. Use of high concentration of KI enabled determination of the gas-phase diffusion coefficients of NO3 in H2O vapor, He, N-2 and O-2 to be, respectively, D-NO3-H2O=120+/-15, D-NO3-He=345+/-25 D-NO3-N2=80+/-15 and D-NO3-O2=80+/-15 Torr cm(2) s(-1). These coefficients agree well with calculated values. C1 UNIV COLORADO, COOPERAT INST RES ENVIRONM SCI, BOULDER, CO 80309 USA. NATL INST ENVIRONM STUDIES, TSUKUBA, IBARAKI 305, JAPAN. UNIV COLORADO, DEPT CHEM & BIOCHEM, BOULDER, CO 80303 USA. RP NOAA, AERON LAB, 325 BROADWAY, BOULDER, CO 80303 USA. RI TALUKDAR, RANAJIT/G-4530-2013; Ravishankara, Akkihebbal/A-2914-2011; OI TALUKDAR, RANAJIT/0000-0001-6017-8431; Rudich, Yinon/0000-0003-3149-0201 NR 25 TC 40 Z9 40 U1 2 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 EI 1873-4448 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD OCT 25 PY 1996 VL 261 IS 4-5 BP 467 EP 473 DI 10.1016/0009-2614(96)00980-3 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VP354 UT WOS:A1996VP35400013 ER PT J AU Johnson, RD Hudgens, JW Ashfold, MNR AF Johnson, RD Hudgens, JW Ashfold, MNR TI Excited electronic states of the SiF2 radical studied by resonance enhanced multiphoton ionisation spectroscopy and ab initio methods SO CHEMICAL PHYSICS LETTERS LA English DT Article ID LASER-INDUCED FLUORESCENCE; SILICON; SPECTRUM; DIFLUORIDE; SILYLENES; ATOMS; F2 AB SiF2 radicals have been produced by the gas-phase reaction of SiH4 with F atoms in a flow reactor and detected by mass-resolved resonance enhanced multiphoton ionisation (REMPI) spectroscopy. Two band systems are observed. One, a series of one-photon resonances in the wavelength range 210-230 nm, we associate with the previously documented <(A)over tilde B-1(1)><--<(X)over tilde (1)A(1)> transition. The observed long progression in the excited state bending mode, nu(2), reflects the increase in equilibrium bond angle that accompanies this electronic transition. We also identify three:two-photon resonances in the wavelength range 315-325 nm. Two we can definitely associate with the <(B)over tilde B-1(2)><--<(X)over tilde (1)A(1)> transition. Polarisation studies show the third resonance: to involve an excited state of (1)A(1) symmetry. Guided by the results of companion ab initio calculations we present evidence for and against assignment of this feature as the (vibronically induced) (B) over tilde<--<(X)over tilde 3(0)(1)> band, or as a hitherto unidentified (1)A(1)<--<(X)over tilde (1)A(1) electronic origin. The calculations also enable prediction of the term values of a further eight, as yet unobserved, excited slates of SIF2. C1 UNIV BRISTOL,SCH CHEM,BRISTOL BS8 1TS,AVON,ENGLAND. RP Johnson, RD (reprint author), NIST,CHEM & PHYS PROPERTIES DIV,GAITHERSBURG,MD 20899, USA. OI ashfold, michael/0000-0001-5762-7048 NR 33 TC 6 Z9 6 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD OCT 25 PY 1996 VL 261 IS 4-5 BP 474 EP 480 DI 10.1016/0009-2614(96)00990-6 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VP354 UT WOS:A1996VP35400014 ER PT J AU Forward, RB Tankersley, RA Burke, JS AF Forward, RB Tankersley, RA Burke, JS TI Endogenous swimming rhythms of larval Atlantic menhaden, Brevoortia tyrannus Latrobe: Implications for vertical migration SO JOURNAL OF EXPERIMENTAL MARINE BIOLOGY AND ECOLOGY LA English DT Article DE Atlantic menhaden; Brevoortia tyrannus; larvae; circadian rhythm; diel vertical migration ID SELECTIVE TIDAL TRANSPORT; ESTUARINE CRAB MEGALOPAE; NORTH-CAROLINA ESTUARY; PLEURONECTES-PLATESSA; CONTINENTAL-SHELF; ANGUILLA-ROSTRATA; STREAM TRANSPORT; PLAICE LARVAE; RIVER ESTUARY; DELAWARE BAY AB Atlantic menhaden, Brevoortia tyrannus Latrobe, spawn on the continental shelf. Larvae are transported shoreward where they enter estuaries and metamorphose. Field studies suggest that while offshore, larvae may undergo nocturnal diel vertical migration (DVM), in which they are near the surface during the night and at depth during the day. The DVM pattern is more pronounced in estuaries but the timing of the nocturnal ascent may be related to tides. Larvae appear to swim in the water column during nocturnal rising tide and are less abundant at all other times. This migration pattern would result in up-estuary movement by selective tidal stream transport. The present study measured endogenous swimming rhythms of Atlantic menhaden larvae and related them to possible vertical migration patterns in offshore and estuarine areas. Larvae reared in the laboratory on a diel light:dark cycle were measured at three sizes (7-9 mm, 14-17 mm and 23-27 mm total length [TL]) as representative of larvae in offshore areas, while estuarine larvae (25-30 mm TL) were collected in the Newport River Estuary (N.C.). Swimming was monitored in a column under constant conditions in the laboratory with a time-lapse video system. In all cases, larvae had a similar circadian rhythm. The smallest laboratory reared larvae ascended into the upper portion of the column during the time of night and descended during the time of day. The other laboratory reared and field caught larvae had increased swimming activity during the time of night and reduced activity during the time of day. This circadian activity rhythm would contribute to the nocturnal DVM in offshore and estuarine areas. However, there was no evidence that larvae developed a tidal rhythm in activity that could contribute to selective tidal stream transport in estuaries. C1 UNIV MARYLAND BALTIMORE CTY, DEPT BIOL SCI, CATONSVILLE, MD 21228 USA. NOAA, NATL MARINE FISHERIES SERV, SE FISHERIES CTR, BEAUFORT LAB, BEAUFORT, NC 28516 USA. RP DUKE UNIV, MARINE LAB, SCH ENVIRONM, 135 DUKE MARINE LAB RD, BEAUFORT, NC 28516 USA. NR 47 TC 13 Z9 14 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0981 EI 1879-1697 J9 J EXP MAR BIOL ECOL JI J. Exp. Mar. Biol. Ecol. PD OCT 25 PY 1996 VL 204 IS 1-2 BP 195 EP 207 DI 10.1016/0022-0981(96)02584-1 PG 13 WC Ecology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA VQ305 UT WOS:A1996VQ30500013 ER PT J AU Davis, S Anderson, DT Nesbitt, DJ AF Davis, S Anderson, DT Nesbitt, DJ TI Plucking a hydrogen bond: A near infrared study of all four intermolecular modes in (DF)(2) SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID POTENTIAL-ENERGY SURFACE; QUASI-ADIABATIC CHANNELS; MONTE-CARLO CALCULATIONS; VIBRATIONAL PREDISSOCIATION; HF DIMER; FLUORIDE DIMER; HIGH-RESOLUTION; STRETCHING FUNDAMENTALS; LASER SPECTROSCOPY; TUNNELING DYNAMICS AB The near ir combination band spectra of supersonically cooled (DF)(2) in the 2900 to 3300 cm(-1) region have been recorded with a high resolution slit jet spectrometer. Twelve vibration-rotation-tunneling (VRT) bands are observed, representing each of the four intermolecular modes (van der Waals stretch nu(4), geared bend nu(5), out-of-plane torsion nu(6), and antigeared bend nu(3)) built as combination bands on either the nu(1) (free) or nu(2) (bound) DF stretches. Analysis of the rotationally resolved spectra provide spectroscopic constants, intermolecular frequencies, tunneling splittings, and predissociation rates as a function of both intra- and intermolecular excitation. The intermolecular frequencies demonstrate a small but systematic dependence on intramolecular mode, which is exploited to yield frequency predictions relevant to far-ir studies, as well as facilitate direct comparison with full 6-D quantum calculations on trial potential surfaces. The tunneling splittings demonstrate a much stronger dependence upon intermolecular mode, increasing by as much as an order of magnitude for geared bend excitation. Conversely, high resolution line shape analysis reveals that vibrational predissociation broadening is only modestly affected by intermolecular excitation, and instead exhibits mode specific behavior controlled predominantly by intramolecular excitation. Detailed H/D isotopic vibrational shifts are obtained by comparison with previous combination band studies of all four intermolecular modes in (HF)(2). In contrast to the strong state mixing previously observed for (HF)(2), the van der Waals stretch and geared bend degrees of freedom are largely decoupled in (DF)(2), due to isotopically ''detuning'' of resonances between bend-stretch intermolecular vibrations. Four-dimensional quantum calculations of the (HF)(2) and (DF)(2) eigenfunctions indicate that the isotopic dependence of this bend-stretch resonance behavior is incorrectly predicted by current hydrogen bond potential surfaces. (C) 1996 American Institute of Physics. C1 UNIV COLORADO, DEPT CHEM & BIOCHEM, BOULDER, CO 80309 USA. NATL INST STAND & TECHNOL, BOULDER, CO 80309 USA. RP Davis, S (reprint author), UNIV COLORADO, JOINT INST LAB ASTROPHYS, BOULDER, CO 80309 USA. NR 72 TC 28 Z9 28 U1 0 U2 6 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD OCT 22 PY 1996 VL 105 IS 16 BP 6645 EP 6664 DI 10.1063/1.471978 PG 20 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VM697 UT WOS:A1996VM69700007 ER PT J AU Moschel, A Hyman, RA Zangwill, A Stiles, MD AF Moschel, A Hyman, RA Zangwill, A Stiles, MD TI Magnetization reversal in ultrathin films with monolayer-scale surface roughness SO PHYSICAL REVIEW LETTERS LA English DT Article ID FE FILMS; UNIAXIAL ANISOTROPY; COBALT FILMS; HYSTERESIS; MULTILAYERS; FERROMAGNETISM; CU(100); GROWTH; CO AB The intrinsic anisotropy of nominally flat, ultrathin ferromagnetic films typically is augmented by a uniaxial anisotropy at step edges. We report model calculations of hysteresis for such systems with inplane magnetization and monolayer-scale roughness. The reversal process: is,a combination of domain nucleation at step edges, expansion of these domains through morphological constrictions, and coherent rotation within domains. The initiation of reversal at well separated step edges can explain the very small coercive fields measured for real ultrathin magnetic films. C1 GEORGIA INST TECHNOL,SCH PHYS,ATLANTA,GA 30332. NATL INST STAND & TECHNOL,ELECTRON PHYS GRP,GAITHERSBURG,MD 20899. RI Stiles, Mark/K-2426-2012 OI Stiles, Mark/0000-0001-8238-4156 NR 42 TC 44 Z9 45 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 21 PY 1996 VL 77 IS 17 BP 3653 EP 3656 DI 10.1103/PhysRevLett.77.3653 PG 4 WC Physics, Multidisciplinary SC Physics GA VM890 UT WOS:A1996VM89000042 ER PT J AU Lafferty, WJ Solodov, AM Weber, A Olson, WB Hartmann, JM AF Lafferty, WJ Solodov, AM Weber, A Olson, WB Hartmann, JM TI Infrared collision-induced absorption by N-2 near 4.3 mu m for atmospheric applications: Measurements and empirical modeling SO APPLIED OPTICS LA English DT Article DE nitrogen; collision-induced absorption; infrared ID TEMPERATURE-DEPENDENCE; FUNDAMENTAL-BAND; 2400 CM-1; TRANSMISSION; SPECTRA; MOLECULES; NITROGEN; REGION; N2-N2; PAIRS AB Accurate measurements of collision-induced absorption by pure nitrogen in the fundamental band near 4.3 mu m have been made in the 0-10 atm and 230-300 K pressure and temperature ranges, respectively. A Fourier-transform spectrometer was used with a resolution of 0.5 cm(-1). The current measurements, which agree well with previous ones but are more precise, reveal that weak features are superimposed on the broad N-2 continuum. These features have negligible temperature dependence, and their origin is not clear at the present time. Available experimental data in the 190-300 K temperature range have been used to build a simple empirical model that is suitable for use to compute atmospheric N-2 absorption. Tests indicate that this model is accurate unlike the estimates produced by widely used atmospheric transmission codes. (C) 1996 Optical Society of America C1 RUSSIAN ACAD SCI,INST ATMOSPHER OPT,TOMSK 634055,RUSSIA. UNIV PARIS 11,LAB PHYS MOL & APPLICAT,F-91405 ORSAY,FRANCE. RP Lafferty, WJ (reprint author), NATL INST STAND & TECHNOL,DIV MOL PHYS,GAITHERSBURG,MD 20899, USA. NR 32 TC 53 Z9 53 U1 0 U2 2 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD OCT 20 PY 1996 VL 35 IS 30 BP 5911 EP 5917 DI 10.1364/AO.35.005911 PG 7 WC Optics SC Optics GA VN212 UT WOS:A1996VN21200007 PM 21127602 ER PT J AU Lamb, B Pierce, T Baldocchi, D Allwine, E Dilts, S Westberg, H Geron, C Guenther, A Klinger, L Harley, P Zimmerman, P AF Lamb, B Pierce, T Baldocchi, D Allwine, E Dilts, S Westberg, H Geron, C Guenther, A Klinger, L Harley, P Zimmerman, P TI Evaluation of forest canopy models for estimating isoprene emissions SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID INVENTORY; FLUXES AB During the summer of 1992, isoprene emissions were measured in a mixed deciduous forest near Oak Ridge, Tennessee. Measurements were aimed at the experimental scale-up of emissions from the leaf level to the forest canopy to the mixed layer. Results from the scale-up study are compared to different canopy models for determining the leaf microclimate as input to isoprene emission algorithms. These include (1) no canopy effects, (2) a simple vertical scaling canopy model with a leaf energy balance, and (3) a numerical canopy model which accounts for leaf-sun geometries, photosynthesis, respiration, transpiration, and gas transport in the canopy. Initial evaluation of the models was based upon a standard emission rate factor of 90 mu gC g(-1) hr(-1) (0.42 nmol g(-1) s(-1)) taken from leaf cuvette measurements and a biomass density factor of 203 g m(-2) taken from biomass surveys and a flux footprint analysis. The results indicated that predicted fluxes were consistent among the models to within approximately +/-20%, but that the models overestimated the mean flux by about a factor of 2 and overestimated the maximum observed flux by 30 to 50%. Adjusting the standard emission factor and biomass density each downward by 20% yielded predicted means approximately 20% greater than the observed means and predicted maxima approximately 25%, less than the observed maxima. Accounting for changes in biomass density as a function of direction upwind of the tower improved the overall model performance. C1 US EPA, RES TRIANGLE PK, NC USA. NOAA, ATMOPHER TURBULENCE & DIFFUS DIV, OAK RIDGE, TN USA. NATL CTR ATMOSPHER RES, DIV ATMOSPHER CHEM, BOULDER, CO 80307 USA. RP Lamb, B (reprint author), WASHINGTON STATE UNIV, DEPT CIVIL & ENVIRONM ENGN, LAB ATMOSPHER RES, PULLMAN, WA 99164 USA. RI Baldocchi, Dennis/A-1625-2009; Harley, Peter/E-1856-2014; Guenther, Alex/B-1617-2008 OI Baldocchi, Dennis/0000-0003-3496-4919; Harley, Peter/0000-0002-2647-1973; Guenther, Alex/0000-0001-6283-8288 NR 14 TC 41 Z9 42 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD OCT 20 PY 1996 VL 101 IS D17 BP 22787 EP 22797 DI 10.1029/96JD00056 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VN184 UT WOS:A1996VN18400004 ER PT J AU Levy, H Moxim, WJ Kasibhatla, PS AF Levy, H Moxim, WJ Kasibhatla, PS TI A global three-dimensional time-dependent lightning source of tropospheric NOx SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SEASONAL-VARIATION; AIRCRAFT EMISSIONS; OZONE PRODUCTION; NITROGEN-OXIDES; NITRIC-OXIDE; MODEL; ATMOSPHERE; DISTRIBUTIONS; PACIFIC; VARIABILITY AB The spatial and temporal distribution for a global three-dimensional, time-dependent lightning source of NOx is constructed from a general circulation model's (GCM) deep moist convection statistics [Manabe et al,, 1974; Manabe and Holloway, 1975], observations of cloud-to-cloud and intracloud lightning fractions and the vertical distribution of lightning discharge [Proctor, 1991], and empirical/theoretical estimates of relative lightning frequency resulting from deep moist convection over ocean and over land [Price and Rind, 1992]. We then bracket the annual global emission of NOx from lightning between 2 and 6 Tg N/yr, with a most probable range of 3 to 5 Tg N/yr, by comparing tropospheric NOx simulations from the Geophysical Fluid Dynamics Laboratory Global Chemical Transport Model with measurements of NOx and/or NOy in the mid and upper troposphere where lightning is a major, if not the dominant, source. With this approach, the global magnitude of the lightning source is constrained by observed levels of NOx, while the temporal and spatial distributions of the source are under the control of the parent GCM. Although our lightning source is smaller than many previous estimates, it is still the major source of NOx and NOy in the mid and upper troposphere for a latitude belt running from 30 degrees N to 30 degrees S, an important contributor to summertime free tropospheric levels over the midlatitudes, and a major contributor, even in the lower troposphere,to the low NOx and NOy levels over the remote oceans. C1 MCNC, ENVIRONM PROGRAMS, RES TRIANGLE PK, NC 27709 USA. RP Levy, H (reprint author), PRINCETON UNIV, NOAA, GEOPHYS FLUID DYNAM LAB, POB 308, PRINCETON, NJ 08542 USA. RI Kasibhatla, Prasad/A-2574-2010 NR 61 TC 82 Z9 84 U1 3 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD OCT 20 PY 1996 VL 101 IS D17 BP 22911 EP 22922 DI 10.1029/96JD02341 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VN184 UT WOS:A1996VN18400014 ER PT J AU Lamarque, JF Langford, AO Proffitt, MH AF Lamarque, JF Langford, AO Proffitt, MH TI Cross-tropopause mixing of ozone through gravity wave breaking: Observation and modeling SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID INSITU MEASUREMENTS; STRATOSPHERE; TROPOSPHERE; EXCHANGE; CONSTITUENTS; SIMULATION; ATMOSPHERE; STABILITY; SPECTRUM; LIDAR AB In the companion paper [Langford et al., this issue] clear signatures of ozone modulation by gravity waves in the lower and middle troposphere have been described from lidar observations over Fritz Peak Observatory (39.9 degrees N, 105.3 degrees W) during September 3-4, 1993, and analyzed using a linear model. It is emphasized in that paper that the linear analysis breaks down at the tropopause level. The purpose of this paper is to interpret the ozone observation in the upper troposphere using a high-resolution mesoscale model and analyze the physical processes responsible for the structures in the upper troposphere and lower stratosphere. In particular, it is shown that topographically excited gravity waves that break at the tropopause level are responsible for an irreversible exchange of ozone from the stratosphere to the troposphere. C1 NOAA, AERON LAB, BOULDER, CO 80303 USA. UNIV COLORADO, COOPERAT INST RES ENVIRONM SCI, BOULDER, CO USA. RP Lamarque, JF (reprint author), NATL CTR ATMOSPHER RES, DIV ATMOSPHER CHEM, POB 3000, BOULDER, CO 80307 USA. RI Langford, Andrew/D-2323-2009; Lamarque, Jean-Francois/L-2313-2014 OI Langford, Andrew/0000-0002-2932-7061; Lamarque, Jean-Francois/0000-0002-4225-5074 NR 33 TC 34 Z9 34 U1 0 U2 6 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD OCT 20 PY 1996 VL 101 IS D17 BP 22969 EP 22976 DI 10.1029/96JD02442 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VN184 UT WOS:A1996VN18400019 ER PT J AU Portmann, RW Solomon, S Garcia, RR Thomason, LW Poole, LR McCormick, MP AF Portmann, RW Solomon, S Garcia, RR Thomason, LW Poole, LR McCormick, MP TI Role of aerosol variations in anthropogenic ozone depletion in the polar regions SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SULFURIC-ACID AEROSOL; ANTARCTIC OZONE; CLOUD FORMATION; NITRIC-ACID; HETEROGENEOUS CHEMISTRY; BALLOON OBSERVATIONS; ARCTIC STRATOSPHERE; MIDDLE ATMOSPHERE; VORTEX; WINTER AB A climatology of aerosol surface area inferred from satellite measurements is used as input in a two-dimensional model to study the long-term evolution of polar ozone depletion, especially the Antarctic ozone hole. It is found that volcanic aerosol inputs very likely modulate the severity of the ozone hole. In particular, the rapid deepening of the ozone hole in the early 1980s, as seen, for example, in the Halley Bay total ozone measurements, was probably caused by accelerated heterogeneous chemistry associated with an increase in aerosol surface area due to volcanic injection combined with the anthropogenic perturbation of stratospheric chlorine. This is further substantiated by the large Antarctic ozone decline observed and modeled after the eruption of Mount Pinatubo. A number of factors that influence the ozone hole are also investigated, including the effect of liquid versus frozen aerosol, the effects of denitrification and dehydration, the role of HOx in HCl and ClONO2 recovery, and the effect of chlorine partitioning at the start of winter. Denitrification tends to slightly increase modeled ozone loss, primarily between about 17 and 25 km late in the season, while dehydration tends to decrease the amount of ozone depletion. However, temperature and aerosol amount have the strongest control on the model ozone loss for a given chlorine loading. These findings suggest that future Arctic ozone depletion could be severe in unusually cold winters or years with large volcanic aerosol surface area. C1 NATL CTR ATMOSPHER RES, BOULDER, CO 80307 USA. NASA, LANGLEY RES CTR, AEROSOL RES BRANCH, HAMPTON, VA 23665 USA. UNIV COLORADO, CIRES, BOULDER, CO 80309 USA. RP Portmann, RW (reprint author), NOAA, AERON LAB, 325 S BROADWAY, BOULDER, CO 80303 USA. RI Portmann, Robert/C-4903-2009; OI Portmann, Robert/0000-0002-0279-6087; Thomason, Larry/0000-0002-1902-0840 NR 60 TC 76 Z9 77 U1 1 U2 8 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD OCT 20 PY 1996 VL 101 IS D17 BP 22991 EP 23006 DI 10.1029/96JD02608 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VN184 UT WOS:A1996VN18400021 ER PT J AU Kellogg, GJ Mayes, AM Stockton, WB Ferreira, M Rubner, MF Satija, SK AF Kellogg, GJ Mayes, AM Stockton, WB Ferreira, M Rubner, MF Satija, SK TI Neutron reflectivity investigations of self-assembled conjugated polyion multilayers SO LANGMUIR LA English DT Article ID BY-LAYER MANIPULATION; X-RAY; MOLECULAR FILMS; COPOLYMERS; SCATTERING; SURFACES; POLYMERS AB Neutron reflectivity has been used to study the organization of self-assembled multilayers of sulfonated polyaniline and polyallylamine. Films were prepared by the sequential adsorption of polycations and polyanions from dilute aqueous solutions. Scattering contrast was achieved by selective deuteration of the blocks of bilayers at varying intervals along the film. The multilayer structure was found to be preserved over 40 bilayer depositions, but with an internal organization which decays monotonically away from the substrate. These results suggest that the observed interfacial widths are primarily due to the accumulation of defects as the bilayers are deposited. C1 MIT,DEPT MAT SCI & ENGN,CAMBRIDGE,MA 02139. NATL INST STAND & TECHNOL,DIV REACTOR RADIAT,GAITHERSBURG,MD 20899. RI Costa, Marysilvia/A-3663-2014 OI Costa, Marysilvia/0000-0001-6394-8075 NR 19 TC 76 Z9 76 U1 1 U2 9 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0743-7463 J9 LANGMUIR JI Langmuir PD OCT 16 PY 1996 VL 12 IS 21 BP 5109 EP 5113 DI 10.1021/la960285m PG 5 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA VN325 UT WOS:A1996VN32500019 ER PT J AU Vierheller, TR Foster, MD Wu, H Schmidt, A Knoll, W Satija, S Majkrzak, CF AF Vierheller, TR Foster, MD Wu, H Schmidt, A Knoll, W Satija, S Majkrzak, CF TI Stability of cadmium arachidate Langmuir-Blodgett multilayers as determined by neutron and X-ray reflectivity SO LANGMUIR LA English DT Article ID ATOMIC-FORCE MICROSCOPY; INTEGRATED OPTICAL TECHNIQUES; ORDER-DISORDER TRANSITIONS; INFRARED-SPECTROSCOPY; POLYMER INTERFACES; MASS-SPECTROMETRY; FILMS; MONOLAYERS; DIFFRACTION; THERMODESORPTION AB The thermal stability of Langmuir-Blodgett multilayers of cadmium arachidate and perdeuterated cadmium arachidate layers deposited on hydrophobic silicon is investigated by neutron and X-ray reflectometry. Using this pair of techniques allows one to depth resolve changes induced by annealing and also to discriminate between the behavior of the Cd head lattice and that of the aliphatic tails. All samples initially have ill-defined interfaces between the tails of adjoining protonated and deuterated layers, and some interchange of chains among layers occurs during the deposition process itself. The form of the multilayer structure is thermally stable at 70 and 84 degrees C, even though aliphatic tails are lost gradually due to ablation, leading to noticeable losses when annealing for 1 week at 84 degrees C, These losses occur almost exclusively from the layers closest to air, suggesting that the rate of ablation is considerably higher than that of interdiffusion. There appears to be little interlayer interdiffusion of chains when annealing for several hours at 84 degrees C. We conjecture that the type of interaction anchoring the two layers adjoining an interface may influence the stability of that interface to molecular exchange across it. C1 UNIV AKRON,INST POLYMER SCI,AKRON,OH 44325. MAX PLANCK INST POLYMER RES,D-55021 MAINZ,GERMANY. NIST,GAITHERSBURG,MD 20899. RIKEN,INST PHYS & CHEM RES,FRONTIER RES PROGRAM,WAKO,SAITAMA 35101,JAPAN. NR 50 TC 12 Z9 12 U1 1 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0743-7463 J9 LANGMUIR JI Langmuir PD OCT 16 PY 1996 VL 12 IS 21 BP 5156 EP 5164 DI 10.1021/la960087v PG 9 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA VN325 UT WOS:A1996VN32500026 ER PT J AU Khasanova, NR Izumi, F Hiroi, Z Takano, M Huang, Q Santoro, A AF Khasanova, NR Izumi, F Hiroi, Z Takano, M Huang, Q Santoro, A TI Redetermination of the structure of La2Cu2O5 by neutron powder diffraction SO ACTA CRYSTALLOGRAPHICA SECTION C-CRYSTAL STRUCTURE COMMUNICATIONS LA English DT Article ID X-RAY; RIETVELD-REFINEMENT; SERIES; COPPER AB Dicopper(II) dilanthanum pentaoxide, La2Cu2O5, has been prepared using a high-pressure technique. Its structure at 296 and 10 K was analysed by Rietveld refinements using neutron powder diffraction data. The structure of La2Cu2O5 comprises CuO5 square pyramids connected to each other in three dimensions by corner sharing and ten-coordinate La3+ ions occupying positions next to oxygen vacancies which form tunnels along the c axis. C1 KYOTO UNIV,INST CHEM RES,UJI,KYOTO 611,JAPAN. NIST,DIV REACTOR RADIAT,GAITHERSBURG,MD 20899. RP Khasanova, NR (reprint author), NATL INST RES INORGAN MAT,1-1 NAMIKI,TSUKUBA,IBARAKI 305,JAPAN. NR 15 TC 11 Z9 11 U1 0 U2 2 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0108-2701 J9 ACTA CRYSTALLOGR C JI Acta Crystallogr. Sect. C-Cryst. Struct. Commun. PD OCT 15 PY 1996 VL 52 BP 2381 EP 2384 DI 10.1107/S0108270196006646 PN 10 PG 4 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA VQ629 UT WOS:A1996VQ62900001 ER PT J AU Choquette, SJ Chesler, SN Duewer, DL Wang, SW OHaver, TC AF Choquette, SJ Chesler, SN Duewer, DL Wang, SW OHaver, TC TI Identification and quantitation of oxygenates in gasoline ampules using Fourier transform near-infrared and Fourier transform Raman spectroscopy SO ANALYTICAL CHEMISTRY LA English DT Article ID SQUARES REGRESSION-ANALYSIS; MULTIVARIATE CALIBRATION; OCTANE NUMBERS; SPECTROMETRY; METHANOL; SPECTRA; FIBER AB Oxygenated fuels are gasolines blended with alcohol or ether additives, The U.S. National Institute of Standards and Technology (NIST) provides eight oxygenated gasoline standard reference materials (SRMs) each containing one of four oxygenates at both the 2.0% and 2.7% oxygen mass fraction levels in 20-mL sealed glass ampules, In this study, ET near-IR and FT Raman spectroscopic methods were investigated to nondestructively identify and quantitate the oxygenate concentration in ampules of SRM gasoline, The samples contained any one of the four SRM oxygenates, MTBE, ETBE, TAME, or ETOH, In addition, dual-oxygenate mixtures were examined. The multivariate, statistical calibration technique, partial least-squares, was employed for both near-IR and Raman data to obtain calibration methods to predict the mass fraction of the oxygenate in these gasoline samples, Both spectroscopic techniques were able to unambiguously identify the oxygen additives and quantitate oxygen concentration to an accuracy within 0.1% oxygen mass fraction. C1 UNIV MARYLAND,DEPT CHEM & BIOCHEM,COLLEGE PK,MD 20742. RP Choquette, SJ (reprint author), NATL INST STAND & TECHNOL,DIV ANALYT CHEM,GAITHERSBURG,MD 20899, USA. RI Duewer, David/B-7410-2008 NR 32 TC 43 Z9 43 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD OCT 15 PY 1996 VL 68 IS 20 BP 3525 EP 3533 DI 10.1021/ac960451v PG 9 WC Chemistry, Analytical SC Chemistry GA VL729 UT WOS:A1996VL72900001 ER PT J AU Eack, KB Beasley, WH Rust, WD Marshall, TC Stolzenburg, M AF Eack, KB Beasley, WH Rust, WD Marshall, TC Stolzenburg, M TI X-ray pulses observed above a mesoscale convective system SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SPRITES94 AIRCRAFT CAMPAIGN; ELECTRIC-FIELD; RED-SPRITES; THUNDERSTORMS; MESOSPHERE AB During a balloon flight into and above the stratiform region of a mesoscale convective system, we observed three xray pulses while the balloon was at an altitude of approximately 15 km MSL (atmospheric pressure of 130 mb). These pulses were one to two orders of magnitude above the background xray count rate with peak fluxes between 37 and 270 (cm(2)-s-sr)(-1) and durations of about one second. No significant electric field was measured at the time of these pulses. C1 UNIV MISSISSIPPI,DEPT PHYS & ASTRON,UNIVERSITY,MS 38677. NOAA,NATL SEVERE STORMS LAB,NORMAN,OK 73069. RP Eack, KB (reprint author), UNIV OKLAHOMA,100 E BOYD,ROOM 1310,NORMAN,OK 73019, USA. OI Stolzenburg, Maribeth/0000-0001-8773-8101 NR 21 TC 63 Z9 64 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD OCT 15 PY 1996 VL 23 IS 21 BP 2915 EP 2918 DI 10.1029/96GL02570 PG 4 WC Geosciences, Multidisciplinary SC Geology GA VM610 UT WOS:A1996VM61000013 ER PT J AU Deshler, T Johnson, BJ Hofmann, DJ Nardi, B AF Deshler, T Johnson, BJ Hofmann, DJ Nardi, B TI Correlations between ozone loss and volcanic aerosol at altitudes below 14 km over McMurdo Station, Antarctica SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SULFURIC-ACID AEROSOL; PINATUBO AEROSOL; DEPLETION; PROFILES; ERUPTION AB Ozone and aerosol profiles over McMurdo Station, Antarctica (78 degrees S), have been measured August-October for the years 1986-1995. This spans the development and decay of the recent perturbation to stratospheric aerosol caused by Pinatubo. Volcanic aerosol surface areas, in the 11-14 km region, peaked near 100 mu m(2) cm(-3) in 1991, decaying to 20-30 mu m(2) cm(-3) in 1992, 15-25 mu m(2) cm(-3) in 1993, and to background levels of 4-8 mu m(2) cm(-3) in 1994. Based on these measurements the volcanic aerosol signal persisted over Antarctica for three austral springs, implying an exponential decay rate of about 14 months. The aerosol below 14 km was correlated with previously unobserved ozone loss at these altitudes. Ozone loss rates of 5-15 ppb dy(-1) (0.3-0.5 DU dy(-1)) were observed in the 10-12 and 12-14 km layers. Beginning in 1994, when the aerosol approached its pre-Pinatubo level, ozone loss diminished in the 12-14 km layer, and was not observed in the 10-12 km layer. C1 NOAA,CLIMATE MONITORING & DIAGNOST LAB,BOULDER,CO 80303. RP Deshler, T (reprint author), UNIV WYOMING,DEPT ATMOSPHER SCI,LARAMIE,WY 82071, USA. NR 16 TC 9 Z9 10 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD OCT 15 PY 1996 VL 23 IS 21 BP 2931 EP 2934 DI 10.1029/96GL02819 PG 4 WC Geosciences, Multidisciplinary SC Geology GA VM610 UT WOS:A1996VM61000017 ER PT J AU Kim, JS Seiler, DG Ehrstein, JR AF Kim, JS Seiler, DG Ehrstein, JR TI Determination of densities and mobilities of heavy and light holes in p-type Si using reduced-conductivity-tensor analyses of magnetic-field-dependent Hall and resistivity measurements SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID SEMICONDUCTORS; SILICON; FILMS AB The densities and mobilities of the individual heavy- and light-hole carriers have been simultaneously determined at various temperatures (40 K to 130 K)in three p-type, single-crystal Si samples. The separation of the two-hole components is achieved by multicarrier analyses of magnetic-field-dependent Hall and resistivity measurements within the two-carrier approximation of the reduced-conductivity-tensor scheme. The explicit experimental values for the densities and mobilities of the two-hole components obtained in this work should be considered as a valuable addition to the existing database for silicon material parameters. They should also be useful to silicon device physics and modeling. RP Kim, JS (reprint author), NATL INST STAND & TECHNOL,DIV SEMICOND ELECT,GAITHERSBURG,MD 20899, USA. NR 23 TC 5 Z9 5 U1 1 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD OCT 15 PY 1996 VL 80 IS 8 BP 4425 EP 4428 DI 10.1063/1.363403 PG 4 WC Physics, Applied SC Physics GA VM272 UT WOS:A1996VM27200028 ER PT J AU Hilpert, G Fraser, GT Pine, AS AF Hilpert, G Fraser, GT Pine, AS TI Vibrational couplings and energy flow in complexes of NH3 with HCN, HCCH, and HCCCCH SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID RESONANCE OPTOTHERMAL SPECTROSCOPY; INFRARED-SPECTROSCOPY; HIGH-RESOLUTION; MICROWAVE-SPECTRUM; ACETYLENE DIMER; ABINITIO THEORY; MOLECULAR-BEAM; H STRETCH; FOURIER; PREDISSOCIATION AB A tunable color-center laser and a molecular-beam electric-resonance optothermal spectrometer have been used to record the infrared spectra of the C-H stretching vibrations of HCCH-NH3, HCCD-NH3, NCH-NH3, and HCCCCH-NH3. The hydrogen-bonded C-H stretching vibrations of NCH-NH3, HCCH-NH3, and HCCCCH-NH3 are redshifted by 200.88126(30), 75.1042(38), and 127.4(1) cm(-1) from the respective free monomer modes. The non-hydrogen-bonded C-H stretches are less perturbed by complexation, being blueshifted by 0.2992(3) cm(-1) in HCCCCH-NH3 and redshifted by 1.179(1) cm(-1) in HCCD-NH3. Consistent with the much larger perturbation of the monomer vibration for the bonded C-H stretch, the B rotational constants increase by 1%-2% for the bonded C-H stretch excited NCH-NH3 and HCCH-NH3 complexes, but change by less than 0.1% for the nonbonded C-H stretches in HCCCCH-NH3 and HCCD-NH3. The decoupling of the two C-H stretches in HCCH-NH3 is not sufficient to allow the observation of the nonbonded C-H stretch in the complex, which correlates to the Raman-active symmetric C-H stretch of acetylene. Also, no spectra were observed for the weaker N-H stretching vibrations of the complexes, consistent with the very weak intensities of these modes in the monomer. The homogeneous linewidths of the transitions, assumed to be a measure of the vibrational predissociation rate, are approximately two orders of magnitude larger for the bonded C-H stretches than for the nonbonded C-H stretches. The similarity in homogeneous widths for the nonbonded C-H stretches in HCCD-NH3 and HCCCCH-NH3, of 7-12 MHz, suggests that the rate of vibrational energy flow along acetylene chains is only weakly dependent on chain length. C1 NIST, OPT TECHNOL DIV, GAITHERSBURG, MD 20899 USA. NR 56 TC 15 Z9 15 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-9606 EI 1089-7690 J9 J CHEM PHYS JI J. Chem. Phys. PD OCT 15 PY 1996 VL 105 IS 15 BP 6183 EP 6191 DI 10.1063/1.472476 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VM554 UT WOS:A1996VM55400010 ER PT J AU Swenson, MS Niiler, PP AF Swenson, MS Niiler, PP TI Statistical analysis of the surface circulation of the California Current SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID COASTAL TRANSITION ZONE; NORTH-ATLANTIC; DRIFTER OBSERVATIONS; CURRENT SYSTEM; EDDY FIELDS; OCEAN; FILAMENT; TRAJECTORIES; VARIABILITY; TRANSPORT AB We use a set of mixed-layer drifting buoy trajectories from the California Current (20 degrees N-40 degrees N) during 1985-1990 to obtain statistically reliable estimates of the mean currents, the mean variance field, and the geographically varying. diffusivity, integral timescales, and integral space scales. Typical values for the diffusivity are 1.1-8.7 x 10(7) cm(2) s(-1), while the timescales and space scales are 2.1-7.1 days and 16-59 km, respectively. The variance field displays a strong westward gradient out to 125 degrees W, and diffusivity shows a tendency to decrease toward the southwest part of the domain. Significant anisotropy is found in the variance field near the coastal boundary and at 30 degrees N, 130 degrees W, which is the region where the subarctic and northern subtropical fronts approach the California Current. The antisymmetric component of the diffusivity tensor indicates that cyclonic eddies dominate the mesoscale signature of drifters in this region. We seek simple parameterizations to relate the scales of motion of the random velocity field to the diffusivity by testing least squares fits to kappa(infinity) proportional to u(0)(2)T and kappa(infinity) proportional to u(0)L, where u(0)(2) is the velocity variance. We found no cases for which these two hypotheses could be distinguished. For the meridional component the linear regressions are not successful, which suggests that the meridional departure velocities result from a flow regime that is significantly organized by, for example, waves or coherent structures. A subset of the drifters measured temperature along their tracks, and we use the resultant data to produce the first direct estimates of the horizontal eddy heat nux divergence based on Lagrangian estimates. In addition, we separately compute the ''eddy diffusivity'' parameterization of the eddy heat flux divergence, del . [u'theta'] = del(kappa del Theta), using our diffusivity estimates and a sea surface temperature climatology. The two independent terms agree well, which provides a measure of reassurance about the diffusivity estimates. The eddy heat flux divergence in the California Current is very small (<5 W m(-2)) and does not appear to be significant in the long-term heat budget of the upper ocean in this region. C1 UNIV CALIF SAN DIEGO, SCRIPPS INST OCEANOG, LA JOLLA, CA 92093 USA. RP Swenson, MS (reprint author), NOAA, ATLANTIC OCEANOG & METEOROL LAB, 4301 RICKENBACKER CAUSEWAY, MIAMI, FL 33149 USA. NR 39 TC 92 Z9 92 U1 1 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD OCT 15 PY 1996 VL 101 IS C10 BP 22631 EP 22645 DI 10.1029/96JC02008 PG 15 WC Oceanography SC Oceanography GA VM834 UT WOS:A1996VM83400010 ER PT J AU Trier, SB Skamarock, WC LeMone, MA Parsons, DB Jorgensen, DP AF Trier, SB Skamarock, WC LeMone, MA Parsons, DB Jorgensen, DP TI Structure and evolution of the 22 February 1993 TOGA COARE squall line: Numerical simulations SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID MESOSCALE CONVECTIVE SYSTEM; DOPPLER RADAR ANALYSIS; BULK PARAMETERIZATION; TROPICAL CONVECTION; KINEMATIC STRUCTURE; SURFACE PRESSURE; TRAILING REGION; STRATIFORM RAIN; PRECIPITATION; DYNAMICS AB In this study a numerical cloud model is used to simulate the three-dimensional evolution of an oceanic tropical squall line observed during the Tropical Ocean Global Atmosphere Coupled Ocean-Atmosphere Response Experiment and investigate the impact of small-scale physical processes including surface fluxes and ice microphysics on its structure and evolution. The observed squall line was oriented perpendicular to a moderately strong low-level jet. Salient features that are replicated by the model include an upshear-tilted leading convective region with multiple updraft maxima during its linear stage and the development of a 30-km scale midlevel vortex and associated transition of the line to a pronounced bow-shaped structure. In this modeling approach, only surface fluxes and stresses that differ from those of the undisturbed environment are included. This precludes an unrealistically large modification to the idealized quasi-steady base state and thus allows us to more easily isolate effects of internally generated surface fluxes and stresses on squall line evolution. Neither surface fluxes and stresses nor ice microphysics are necessary to simulate the salient features of the squall line. Their inclusion, however, results in differences in the timing of squall line evolution and greater realism of certain structural characteristics. Significant differences in the convectively induced cold pool strength occur between the early stages of simulations that included ice microphysics and a simulation that contained only warm-rain microphysical processes. The more realistic strength and depth of the cold pool in the simulations that contained ice processes is consistent with an updraft tilt that more closely resembles observations. The squall-line-induced surface fluxes also influence the strength but, more dramatically, the areal extent of the surface cold pool. For the majority of the 6-h simulation, this influence on the cold pool strength is felt only within several hundred meters of the surface. Significant impact oi squall-line-induced surface fluxes on the evolving deep convectional the leading edge of the cold pool is restricted to the later stages (t greater than or equal to 4 h) of simulations and is most substantial in regions where the ground-relative winds are strong and the convectively induced cold pool is initially weak and shallow. C1 NOAA,NSSL,MESOSCALE RES DIV,BOULDER,CO. RP Trier, SB (reprint author), NATL CTR ATMOSPHER RES,POB 3000,BOULDER,CO 80307, USA. NR 71 TC 81 Z9 84 U1 1 U2 6 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD OCT 15 PY 1996 VL 53 IS 20 BP 2861 EP 2886 DI 10.1175/1520-0469(1996)053<2861:SAEOTF>2.0.CO;2 PG 26 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VP767 UT WOS:A1996VP76700001 ER PT J AU Ryzhkov, AV Zrnic, DS AF Ryzhkov, AV Zrnic, DS TI Rain in shallow and deep convection measured with a polarimetric radar SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID SIZE DISTRIBUTION; EVOLUTION; PRECIPITATION; COALESCENCE; BREAKUP AB The authors contrast rainfall in two Oklahoma squall lines: one with deep convection occurred in the spring and the other with shallower convection in the winter. Both passed over a micronetwork of densely spaced rain gauges and were observed with the National Severe Storm Laboratory's polarimetric weather radar. Polarimetric measurements reveal differences in storm structure that in turn imply that microphysical processes caused the drop size distributions to be quite distinct for the two events. In the winter squall line the conventional R(Z) algorithm for estimating rainfall fails badly, whereas in the summer squall line it performs well. The method based on specific differential phase measurements, however, yields a very good match between radar-derived areal precipitation amount and rain depth obtained from the micronetwork of densely located rain gauges for both events. C1 NOAA,NATL SEVERE STORMS LAB,NORMAN,OK 73069. UNIV OKLAHOMA,COOPERAT INST MESOSCALE METEOROL STUDIES,NORMAN,OK 73019. NR 21 TC 9 Z9 9 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD OCT 15 PY 1996 VL 53 IS 20 BP 2989 EP 2995 DI 10.1175/1520-0469(1996)053<2989:RISADC>2.0.CO;2 PG 7 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VP767 UT WOS:A1996VP76700008 ER PT J AU Xie, YL Ludwig, KF Bansil, R Gallagher, PD Cao, XX Morales, G AF Xie, YL Ludwig, KF Bansil, R Gallagher, PD Cao, XX Morales, G TI Small-angle X-ray scattering studies of semidilute polystyrene-cyclohexane solutions SO PHYSICA A LA English DT Article ID CONCENTRATED POLYMER-SOLUTIONS; TEMPERATURE-CONCENTRATION DIAGRAM; NEUTRON-SCATTERING; LIGHT-SCATTERING; SPINODAL DECOMPOSITION; MEAN-FIELD; CROSSOVER; DYNAMICS; CURVE; BLEND AB Small-angle X-ray scattering was used to study semidilute polystyrene-cyclohexane solutions at temperatures from below the coexistence curve to above the Theta point. Deviations from Theta point concentration scaling were observed as the coexistence line was approached. A new scaling form is suggested which combines the concentration scaling near the Theta paint with the temperature scaling near a spinodal; it collapses the experimental data. This approach assumes that the ''bare'' correlation length xi(0) scales as c(-1). The observed low-angle ''excess scattering'' is best described by the Debye-Bueche random heterogeneity model, rather than the attractive potential model of Medjahdi and co-workers. The ''excess scattering'' is virtually independent of temperature, suggesting that the inhomogeneities which cause it are not affected by the approaching phase transformation. C1 BOSTON UNIV,DEPT PHYS,BOSTON,MA 02215. BOSTON UNIV,CTR POLYMER STUDIES,BOSTON,MA 02215. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. BOSTON UNIV,DEPT CHEM,BOSTON,MA 02215. NR 34 TC 12 Z9 12 U1 1 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-4371 J9 PHYSICA A JI Physica A PD OCT 15 PY 1996 VL 232 IS 1-2 BP 94 EP 108 DI 10.1016/0378-4371(96)00218-X PG 15 WC Physics, Multidisciplinary SC Physics GA VN659 UT WOS:A1996VN65900008 ER PT J AU Schwieters, CD Alford, JA Delos, JB AF Schwieters, CD Alford, JA Delos, JB TI Semiclassical scattering in a circular semiconductor microstructure SO PHYSICAL REVIEW B LA English DT Article ID PHASE-COHERENT CONDUCTANCE; PERIODIC-ORBIT THEORY; BALLISTIC-TRANSPORT; QUANTUM-DOT; CHAOTIC SCATTERING; ANTIDOT LATTICES; FLUCTUATIONS; MAGNETOCONDUCTANCE; CONDUCTIVITY; STADIUM AB The conductance of a microscopic junction shows fluctuations caused by quantum interference of waves that follow different paths between the leads. We give a semiclassical formula for these fluctuations. The theory utilizes trajectories which travel between the centers of the lead apertures; it also incorporates diffraction at these apertures. We extend the theory to include ''ghost paths,'' which scatter diffractively off the lead mouths. Semiclassical S-matrix elements are computed for a circular junction over a range of Fermi wave numbers, and the large-scale structure of these matric elements shows good agreement with quantum results. Finally, we propose a hypothesis about the effect of the quantum coherence length on the S matrix and on the semiclassical sum. C1 UNIV COLORADO, JOINT INST LAB ASTROPHYS, BOULDER, CO 80309 USA. NATL INST STAND & TECHNOL, BOULDER, CO 80309 USA. RP Schwieters, CD (reprint author), COLL WILLIAM & MARY, DEPT PHYS, WILLIAMSBURG, VA 23187 USA. NR 37 TC 58 Z9 60 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD OCT 15 PY 1996 VL 54 IS 15 BP 10652 EP 10668 DI 10.1103/PhysRevB.54.10652 PG 17 WC Physics, Condensed Matter SC Physics GA VT674 UT WOS:A1996VT67400069 ER PT J AU Jablonski, A Tilinin, IS Powell, CJ AF Jablonski, A Tilinin, IS Powell, CJ TI Mean escape depth of signal photoelectrons from amorphous and polycrystalline solids SO PHYSICAL REVIEW B LA English DT Article ID ELASTIC-SCATTERING; NONCRYSTALLINE SOLIDS; ELECTRON ATTENUATION; ANGULAR-DISTRIBUTION; AUGER ELECTRONS; MONTE-CARLO; FREE PATHS; PHOTOEMISSION; SPECTROSCOPY; TRANSPORT AB The mean escape depth (MED) of the signal photoelectrons in x-ray photoelectron spectroscopy (XPS) is a useful measure of the surface sensitivity in WS measurements. The MED has previously been given by the product of the inelastic mean free path for the signal electrons and the cosine of the photoelectron emission angle, but, due to anisotropy in photoemission and to the effects of elastic electron scattering, evaluation of MED has become more complex. The theoretical formulation presented here is based on the solution of a kinetic equation within the transport approximation. This approximation allows us to solve the boundary-value problem with simplifying assumptions for the scattering properties of atoms constituting an amorphous or polycrystalline solid. To illustrate this approach, MED values have been computed for the 2s, 3s, and 4s subshells of aluminum, silver, and gold, respectively, for a large number of possible experimental configurations, and compared with corresponding MED values obtained from Monte Carlo simulations; satisfactory agreement has been obtained. Similar comparisons have also been made for the 3p and 3d subshells of silver, again with good agreement. It has been found that the MED is strongly affected by elastic scattering of electrons on their way out of the solid. The MED Values are up to about 30% less than the values expected from the oversimplified formalism (where elastic electron-scattering effects are neglected) for near-normal emission angles although MED Values can be much larger (by up to about a factor of 2) than those from the simple theory for near-grazing emission angles or for certain other experimental configurations. These calculations show that MED values can deviate substantially (typically by +/-30% for common measurement conditions) from those expected from the simple formalism due to combined effects of elastic electron scattering and of anisotropy in the photoionization process. MED values can be calculated much more rapidly, by orders of magnitude, with the new formalism than from Monte Carlo simulations. C1 NATL INST STAND & TECHNOL,SURFACE & MICROANAL SCI DIV,GAITHERSBURG,MD 20899. RP Jablonski, A (reprint author), POLISH ACAD SCI,INST PHYS CHEM,KASPRZAKA 44-52,PL-01224 WARSAW,POLAND. NR 40 TC 69 Z9 69 U1 1 U2 5 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD OCT 15 PY 1996 VL 54 IS 15 BP 10927 EP 10937 DI 10.1103/PhysRevB.54.10927 PG 11 WC Physics, Condensed Matter SC Physics GA VT674 UT WOS:A1996VT67400100 ER PT J AU Shirley, EL Benedict, LX Louie, SG AF Shirley, EL Benedict, LX Louie, SG TI Excitons in solid C-60 SO PHYSICAL REVIEW B LA English DT Article ID QUASI-PARTICLE; ELECTRONIC-PROPERTIES; C60; BUCKMINSTERFULLERENE; ABSORPTION; SPECTRA; SPECTROSCOPY; TRANSITIONS; IONIZATION; ENERGIES AB Exciton levels in undoped, solid C-60 are calculated using a model Hamiltonian. We find excitation energies of 1.58 and 1.30 eV for the lowest singlet and triplet exciton, respectively, in comparison with the measured energies of 1.83 and 1.55 eV. Singlet and triplet states have similar energy diagrams, wherein exciton states having T-2g, T-1g, G(g), and H-g Symmetries are separated by up to several tenths of an electron volt. As a function of crystal momentum? exciton energies exhibit dispersion from 20 to 40 meV. Theoretical pressure derivatives of exciton energies are presented. C1 UNIV CALIF BERKELEY, DEPT PHYS, BERKELEY, CA 94720 USA. UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, DIV MAT SCI, BERKELEY, CA 94720 USA. RP Shirley, EL (reprint author), NATL INST STAND & TECHNOL, PHYS LAB, OPT TECH DIV, GAITHERSBURG, MD 20899 USA. NR 34 TC 47 Z9 47 U1 0 U2 11 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD OCT 15 PY 1996 VL 54 IS 15 BP 10970 EP 10977 DI 10.1103/PhysRevB.54.10970 PG 8 WC Physics, Condensed Matter SC Physics GA VT674 UT WOS:A1996VT67400104 ER PT J AU Lu, ZT Corwin, KL Renn, MJ Anderson, MH Cornell, EA Wieman, CE AF Lu, ZT Corwin, KL Renn, MJ Anderson, MH Cornell, EA Wieman, CE TI Low-velocity intense source of atoms from a magneto-optical trap. SO PHYSICAL REVIEW LETTERS LA English DT Article ID VAPOR-CELL; BEAM; FUNNEL; LIGHT; SLOW; COLD AB We have produced and characterized an intense, slow, and highly collimated atomic beam extracted from a standard vapor cell magneto-optical trap (MOT). The technique used is dramatically simpler than previous methods for producing very cold atomic beams. We have created a 0.6 mm diameter rubidium atomic beam with a continuous flux of 5 x 10(9)/s and a pulsed flux 10 times greater. Its longitudinal velocity distribution is centered at 14 m/s with a FWHM of 2.7 m/s. Through an efficient recycling process, 70% of the atoms trapped in the MOT are loaded into the atomic beam. C1 UNIV COLORADO,DEPT PHYS,BOULDER,CO 80309. RP Lu, ZT (reprint author), NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,325 BROADWAY,BOULDER,CO 80309, USA. RI Corwin, Kristan/A-1331-2013 NR 17 TC 192 Z9 199 U1 7 U2 24 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 14 PY 1996 VL 77 IS 16 BP 3331 EP 3334 DI 10.1103/PhysRevLett.77.3331 PG 4 WC Physics, Multidisciplinary SC Physics GA VM032 UT WOS:A1996VM03200016 ER PT J AU Kley, D Crutzen, PJ Smit, HGJ Vomel, H Oltmans, SJ Grassl, H Ramanathan, V AF Kley, D Crutzen, PJ Smit, HGJ Vomel, H Oltmans, SJ Grassl, H Ramanathan, V TI Observations of near-zero ozone concentrations over the convective Pacific: Effects on air chemistry SO SCIENCE LA English DT Article ID EQUATORIAL PACIFIC; TROPOSPHERIC OZONE; BOUNDARY-LAYER; GTE CITE-1; DISTRIBUTIONS; CYCLES; OCEAN AB A series of measurements over the equatorial Pacific in March 1993 showed thai the volume mixing ratios of ozone were frequently well below 10 nanomoles per mole both in the marine boundary layer (MEL) and between 10 kilometers and the tropopause. These latter unexpected results emphasize the enormous variability of tropical tropospheric ozone and hydroxyl concentrations, which determine the oxidizing efficiency of the trophosphere. They also imply a convective short circuit of marine gaseous emissions, such as dimethyl sulfide, between the MBL and the uppermost troposphere, leading, for instance, to sulfate particle formation. C1 MAX PLANCK INST CHEM, D-55020 MAINZ, GERMANY. UNIV CALIF SAN DIEGO, SCRIPPS INST OCEANOG, CTR CLOUDS CHEM & CLIMATE, LA JOLLA, CA 92093 USA. NOAA, CLIMATE MONITORING & DIAGNOST LAB, BOULDER, CO 80303 USA. WORLD METEOROL ORG, WORLD CLIMATE RES PROGRAMME, GENEVA, SWITZERLAND. RP Kley, D (reprint author), FORSCHUNGSZENTRUM JULICH, FORSCHUNGSZENTRUM, INST CHEM & DYNAM GEOSPHARE, POSTFACH 1913, D-52425 JULICH, GERMANY. RI Crutzen, Paul/F-6044-2012; Smit, Herman/J-2397-2012 OI Smit, Herman/0000-0002-2268-4189 NR 36 TC 158 Z9 162 U1 3 U2 22 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD OCT 11 PY 1996 VL 274 IS 5285 BP 230 EP 233 DI 10.1126/science.274.5285.230 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA VM671 UT WOS:A1996VM67100038 ER PT J AU Grah, M Alzebdeh, K Sheng, PY Vaudin, MD Bowman, KJ Ostoja-Starzewski, M AF Grah, M Alzebdeh, K Sheng, PY Vaudin, MD Bowman, KJ Ostoja-Starzewski, M TI Brittle-intergranular failure in 2D microstructures: Experiments and computer simulations SO ACTA MATERIALIA LA English DT Article ID SHEET AB Brittle intergranular fracture (BIF) is a common mode of failure for monolithic ceramics and intermetallics, as well as for some refractory metals and metals exposed to environmental corrosion, stress corrosion cracking or high temperature creep. As interest in applications for these materials grows, research programs have been developed to characterize and predict their fracture behavior. In order to experimentally quantify the effects of microstructure on local BIF, systems which have a minimum number of variables which influence fracture must be used. Evaluation of materials with two dimensional (2D) microstructures can considerably reduce the complexity of the system. In addition, providing a biaxial stress state in the 2D microstructure ensures that all boundaries experience exclusively Mode I loading prior to failure. Biaxial elastic loading of this simplified microstructure allows the calculation of (a) local stress and strain fields (and their concentrations) prior to failure, as well as (b) prediction of grain boundary strength criteria, and (c) prediction of intergranular crack paths. This can be achieved by conducting computer simulations of the experimentally observed fracture phenomena in polycrystalline specimens having a given texture and microgeometry. These simulations use high resolution finite-difference grids below the crystal scale, and involve the derivation of a spring-network model for arbitrary in-plane crystal anisotropy. Since the grain boundary strength criterion is easily controllable in such simulations, it can be inferred by a comparison with actual experimental results. The latter is complemented by results on fracture of materials with very weak grain boundaries, thus providing a clear perspective on evolution of the failure process for varying degrees of embrittlement. Copyright (C) 1996 Acta Metallurgica Inc. C1 MICHIGAN STATE UNIV, DEPT MECH & MAT SCI, E LANSING, MI 48824 USA. MGA RES CORP, MADISON HTS, MI 48071 USA. NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. PURDUE UNIV, SCH MAT ENGN, W LAFAYETTE, IN 47907 USA. INST PAPER SCI & TECHNOL, ATLANTA, GA 30318 USA. GEORGIA INST TECHNOL, ATLANTA, GA 30318 USA. RP Grah, M (reprint author), MICHELIN R&D CORP, POB 1987, GREENVILLE, SC 29606 USA. OI Alzebdeh, Khalid/0000-0002-2310-6620; Ostoja-Starzewski, Martin/0000-0002-3493-363X NR 28 TC 36 Z9 37 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1359-6454 J9 ACTA MATER JI Acta Mater. PD OCT 10 PY 1996 VL 44 IS 10 BP 4003 EP 4018 DI 10.1016/S1359-6454(96)00044-4 PG 16 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA VL575 UT WOS:A1996VL57500011 ER PT J AU Crenshaw, DM RodriguezPascual, PM Penton, SV Edelson, RA Alloin, D Ayres, TR Clavel, J Horne, K Johnson, WN Kaspi, S Korista, KT Kriss, GA Krolik, JH Malkan, MA Maoz, D Netzer, H OBrien, PT Peterson, BM Reichert, GA Shull, JM Ulrich, MH Wamsteker, W Warwick, RS Yaqoob, T Balonek, TJ Barr, P Bromage, GE Carini, M Carone, TE Cheng, FZ Chuvaev, KK Dietrich, M Doroshenko, VT DultzinHacyan, D Filippenko, AV Gaskell, CM Glass, IS Goad, MR Hutchings, J Kazanas, D Kollatschny, W Koratkar, AP Laor, A Leighly, K Lyutyi, VM MacAlpine, GM Malkov, YF Martin, PG McCollum, B Merkulova, NI Metik, L Metlov, VG Miller, HR Morris, SL Oknyanskij, VL Penfold, J Perez, E Perola, GC Pike, G Pogge, RW Pronik, I Pronik, VI Ptak, RL RecondoGonzalez, MC RodriguezEspinoza, JM Rokaki, EL Roland, J Sadun, AC Salamanca, I SantosLleo, M Sergeev, SG Smith, SM Snijders, MAJ Sparke, LS Stirpe, GM Stoner, RE Sun, WH vanGroningen, E Wagner, RM Wagner, S Wanders, I Welsh, WF Weymann, RJ Wilkes, BJ Zheng, W AF Crenshaw, DM RodriguezPascual, PM Penton, SV Edelson, RA Alloin, D Ayres, TR Clavel, J Horne, K Johnson, WN Kaspi, S Korista, KT Kriss, GA Krolik, JH Malkan, MA Maoz, D Netzer, H OBrien, PT Peterson, BM Reichert, GA Shull, JM Ulrich, MH Wamsteker, W Warwick, RS Yaqoob, T Balonek, TJ Barr, P Bromage, GE Carini, M Carone, TE Cheng, FZ Chuvaev, KK Dietrich, M Doroshenko, VT DultzinHacyan, D Filippenko, AV Gaskell, CM Glass, IS Goad, MR Hutchings, J Kazanas, D Kollatschny, W Koratkar, AP Laor, A Leighly, K Lyutyi, VM MacAlpine, GM Malkov, YF Martin, PG McCollum, B Merkulova, NI Metik, L Metlov, VG Miller, HR Morris, SL Oknyanskij, VL Penfold, J Perez, E Perola, GC Pike, G Pogge, RW Pronik, I Pronik, VI Ptak, RL RecondoGonzalez, MC RodriguezEspinoza, JM Rokaki, EL Roland, J Sadun, AC Salamanca, I SantosLleo, M Sergeev, SG Smith, SM Snijders, MAJ Sparke, LS Stirpe, GM Stoner, RE Sun, WH vanGroningen, E Wagner, RM Wagner, S Wanders, I Welsh, WF Weymann, RJ Wilkes, BJ Zheng, W TI Multiwavelength observations of short-timescale variability in NGC 4151 .1. Ultraviolet observations SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies, active; galaxies, individual (NGC 4151); galaxies, Seyfert; ultraviolet, galaxies ID BROAD-LINE REGION; ACTIVE GALACTIC NUCLEI; X-RAY; DETAILED OBSERVATIONS; SEYFERT-GALAXIES; OPTICAL WAVELENGTHS; NGC-4151; IUE; NGC-5548; SIZE AB We present the results of an intensive ultraviolet monitoring campaign on the Seyfert 1 galaxy NGC 4151, as part of an effort to study its short-timescale variability over a broad range in wavelength. The nucleus of NGC 4151 was observed continuously with the International Ultraviolet Explorer for 9.3 days, yielding a pair of LWP and SWP spectra every similar to 70 minutes, and during 4 hr periods for 4 days prior to and 5 days after the continuous-monitoring period. The sampling frequency of the observations is an order of magnitude higher than that of any previous UV monitoring campaign on a Seyfert galaxy. The continuum fluxes in bands from 1275 to 2688 Angstrom went through four significant and well-defined ''events'' of duration 2-3 days during the continuous-monitoring period. We find that the amplitudes of the continuum variations decrease with increasing wavelength, which extends a general trend for this and other Seyfert galaxies to smaller timescales (i.e., a few days). The continuum variations in all the UV bands are simultaneous to within an accuracy of similar to 0.15 days, providing a strict constraint on continuum models. The emission-line light curves show only one major event during the continuous monitoring (a slow rise followed by a shallow dip) and do not correlate well with continuum light curves over the short duration of the campaign, because the timescale for continuum variations is apparently smaller than the response times of the emission lines. C1 EUROPEAN SPACE AGCY, IUE OBSERV, E-28080 MADRID, SPAIN. UNIV COLORADO, CTR ASTROPHYS & SPACE ASTRON, BOULDER, CO 80309 USA. UNIV IOWA, DEPT PHYS & ASTRON, IOWA CITY, IA 52242 USA. OBSERV PARIS, CNRS, URA 173, F-92195 MEUDON, FRANCE. ESTEC, EUROPEAN SPACE AGCY, DIV ASTROPHYS, ISO OBSERV, NL-2200 AG NOORDWIJK, NETHERLANDS. UNIV ST ANDREWS, SCH PHYS & ASTRON, ST ANDREWS KY16 9SS, FIFE, SCOTLAND. USN, RES LAB, WASHINGTON, DC 20375 USA. TEL AVIV UNIV, RAYMOND & BEVERLY SACKLER FAC EXACT SCI, SCH PHYS & ASTRON, IL-69978 TEL AVIV, ISRAEL. TEL AVIV UNIV, RAYMOND & BEVERLY SACKLER FAC EXACT SCI, WISE OBSERV, IL-69978 TEL AVIV, ISRAEL. UNIV KENTUCKY, DEPT PHYS & ASTRON, LEXINGTON, KY 40506 USA. JOHNS HOPKINS UNIV, DEPT PHYS & ASTRON, BLOOMBERG CTR, BALTIMORE, MD 21218 USA. UNIV CALIF LOS ANGELES, DEPT ASTRON, LOS ANGELES, CA 90024 USA. UNIV OXFORD, DEPT ASTRON, OXFORD OX1 3RH, ENGLAND. OHIO STATE UNIV, DEPT ASTRON, COLUMBUS, OH 43210 USA. NASA, GODDARD SPACE FLIGHT CTR, UNIV SPACE RES ASSOC, GREENBELT, MD 20771 USA. UNIV COLORADO, JOINT INST LAB ASTROPHYS, BOULDER, CO 80309 USA. UNIV COLORADO, NATL INST STAND & TECHNOL, BOULDER, CO 80309 USA. European So Observ, D-85748 Garching, GERMANY. Univ Leicester, Dept Phys & Astron, Leicester LE1 7RH, Leics, ENGLAND. NASA, Goddard Space Flight Ctr, Lab High Energy Astrophys, Greenbelt, MD 20771 USA. Colgate Univ, Dept Phys & Astron, Hamilton, NY 13346 USA. Univ Cent Lancashire, Ctr Astrophys, Preston PR1 2HE, Lancs, ENGLAND. Western Kentucky Univ, Dept Phys & Astron, Ctr Automated Space Studies, Bowling Green, KY 42101 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ Sci & Technol China, Ctr Astrophys, Hefei 230026, Anhui, PEOPLES R CHINA. Landessternwarte Konigstuhl, D-69117 Heidelberg, GERMANY. Sternberg State Astron Inst, UA-334413 Crimea, UKRAINE. Univ Nacl Autonoma Mexico, Inst Astron, Mexico City 04510, DF, MEXICO. Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. Univ Nebraska, Dept Phys & Astron, Lincoln, NE 68588 USA. S African Astron Observ, ZA-7935 Observ, SOUTH AFRICA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Dominion Astrophys Observ, Victoria, BC V8X 4M6, CANADA. Univ Sternwarte Gottingen, D-37083 Gottingen, GERMANY. CALTECH, Dept Astron, Pasadena, CA 91125 USA. RIKEN, Cosm Radiat Lab, Wako, Saitama 35101, JAPAN. Univ Moscow, Sternberg Astron Inst, Moscow 119899, RUSSIA. Univ Michigan, Dept Astron, Ann Arbor, MI 48109 USA. Crimean Astrophys Observ, UA-334413 Crimea, UKRAINE. Univ Toronto, Canadian Inst Theoret Astrophys, Toronto, ON M5S 1A1, CANADA. NASA, Goddard Space Flight Ctr, Comp Sci Corp, Greenbelt, MD 20771 USA. Georgia State Univ, Dept Phys & Astron, Atlanta, GA 30303 USA. Astron Observ, S-75120 Uppsala, SWEDEN. Univ Calgary, Dept Phys & Astron, Calgary, AB T2N 1N4, CANADA. Mt Royal Coll, Dept Math Phys & Engn, Calgary, AB T3E 6K6, CANADA. Inst Astrofis Andalucia, E-18080 Granada, SPAIN. Univ Rome, Inst Astron, I-00161 Rome, ITALY. Bowling Green State Univ, Dept Phys & Astron, Bowling Green, OH 43403 USA. Inst Astrofis Canarias, E-38200 La Laguna, Tenerife, SPAIN. Univ Edinburgh, Royal Observ Edinburgh, Edinburgh EH9 3HJ, Midlothian, SCOTLAND. Inst Astrophys, F-75014 Paris, FRANCE. Agnes Scott Coll, Dept Phys & Astron, Decatur, GA 30030 USA. Agnes Scott Coll, Bradley Observ, Decatur, GA 30030 USA. Inst Radio Astron Millimetr, F-38046 St Martin Dheres, FRANCE. Univ Wisconsin, Dept Astron, Madison, WI 53706 USA. Osservatorio Astron Bologna, I-40126 Bologna, ITALY. Natl Cent Univ, Inst Astron, Chungli 32054, TAIWAN. Lowell Observ, Flagstaff, AZ 86001 USA. Keele Univ, Dept Phys, Keele ST5 5BG, Staffs, ENGLAND. Observ Carnegie Inst Washington, Pasadena, CA 91101 USA. Harvard Univ, Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Crenshaw, DM (reprint author), NASA, GODDARD SPACE FLIGHT CTR, ASTRON & SOLAR PHYS LAB, COMP SCI CORP, CODE 681, GREENBELT, MD 20771 USA. RI Morris, Simon/G-7981-2011; Oknyanskij, Victor/I-9267-2012; Johnson, Neil/G-3309-2014; Recondo, Carmen/B-1215-2012; Stirpe, Giovanna/O-9393-2015; OI Perez, Enrique/0000-0001-9737-4559; Morris, Simon/0000-0003-4866-110X; Recondo, Carmen/0000-0001-9813-6798; Stirpe, Giovanna/0000-0002-3702-8731; Gaskell, C/0000-0003-4888-2009; Wilkes, Belinda/0000-0003-1809-2364 NR 53 TC 66 Z9 66 U1 0 U2 4 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 10 PY 1996 VL 470 IS 1 BP 322 EP 335 DI 10.1086/177869 PN 1 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VL723 UT WOS:A1996VL72300025 ER PT J AU Edelson, RA Alexander, T Crenshaw, DM Kaspi, S Malkan, MA Peterson, BM Warwick, RS Clavel, J Filippenko, AV Horne, K Korista, KT Kriss, GA Krolik, JH Maoz, D Nandra, K OBrien, PT Penton, SV Yaqoob, T Albrecht, P Alloin, D Ayres, TR Balonek, TJ Barr, P Barth, AJ Bertram, R Bromage, GE Carini, M Carone, TE Cheng, FZ Chuvaev, KK Dietrich, M DultzinHacyan, D Gaskell, CM Glass, IS Goad, MR Hemar, S Ho, LC Huchra, JP Hutchings, J Johnson, WN Kazanas, D Kollatschny, W Koratkar, AP Kovo, O Laor, A MacAlpine, GM Magdziarz, P Martin, PG Matheson, T McCollum, B Miller, HR Morris, SL Oknyanskij, VL Penfold, J Perez, E Perola, GC Pike, G Pogge, RW Ptak, RL Qian, BC RecondoGonzalez, MC Reichert, GA RodriguezEspinoza, JM RodriguezPascual, PM Rokaki, EL Roland, J Sadun, AC Salamanca, I SantosLleo, M Shields, JC Shull, JM Smith, DA Smith, SM Snijders, MAJ Stirpe, GM Stoner, RE Sun, WH Ulrich, MH vanGroningen, E Wagner, RM Wagner, S Wanders, I Welsh, WF Weymann, RJ Wilkes, BJ Wu, H Wurster, J Xue, SJ Zdziarski, AA Zheng, W Zou, ZL AF Edelson, RA Alexander, T Crenshaw, DM Kaspi, S Malkan, MA Peterson, BM Warwick, RS Clavel, J Filippenko, AV Horne, K Korista, KT Kriss, GA Krolik, JH Maoz, D Nandra, K OBrien, PT Penton, SV Yaqoob, T Albrecht, P Alloin, D Ayres, TR Balonek, TJ Barr, P Barth, AJ Bertram, R Bromage, GE Carini, M Carone, TE Cheng, FZ Chuvaev, KK Dietrich, M DultzinHacyan, D Gaskell, CM Glass, IS Goad, MR Hemar, S Ho, LC Huchra, JP Hutchings, J Johnson, WN Kazanas, D Kollatschny, W Koratkar, AP Kovo, O Laor, A MacAlpine, GM Magdziarz, P Martin, PG Matheson, T McCollum, B Miller, HR Morris, SL Oknyanskij, VL Penfold, J Perez, E Perola, GC Pike, G Pogge, RW Ptak, RL Qian, BC RecondoGonzalez, MC Reichert, GA RodriguezEspinoza, JM RodriguezPascual, PM Rokaki, EL Roland, J Sadun, AC Salamanca, I SantosLleo, M Shields, JC Shull, JM Smith, DA Smith, SM Snijders, MAJ Stirpe, GM Stoner, RE Sun, WH Ulrich, MH vanGroningen, E Wagner, RM Wagner, S Wanders, I Welsh, WF Weymann, RJ Wilkes, BJ Wu, H Wurster, J Xue, SJ Zdziarski, AA Zheng, W Zou, ZL TI Multiwavelength observations of short-timescale variability in NGC 4151 .4. Analysis of multiwavelength continuum variability SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies, active; galaxies, individual (NGC 4151); galaxies, Seyfert; ultraviolet, galaxies; X-rays, galaxies ID ACTIVE GALACTIC NUCLEI; OBJECT PKS 2155-304; BROAD-LINE REGION; X-RAY-EMISSION; CFA SEYFERT-GALAXIES; ULTRAVIOLET VARIABILITY; ACCRETION DISKS; COMPTON REFLECTION; BAND PROPERTIES; UV CONTINUUM AB This paper combines data from the three preceding papers in order to analyze the multi-wave-band variability and spectral energy distribution of the Seyfert 1 galaxy NGC 4151 during the 1993 December monitoring campaign. The source, which was near its peak historical brightness, showed strong, correlated variability at X-ray, ultraviolet, and optical wavelengths. The strongest variations were seen in medium-energy (similar to 1.5 keV) X-rays, with a normalized variability amplitude (NVA) of 24%. Weaker (NVA = 6%) variations (uncorrelated with those at lower energies) were seen at soft gamma-ray energies of similar to 100 keV. No significant variability was seen in softer (0.1-1 keV) X-ray bands. In the ultraviolet/optical regime, the NVA decreased from 9% to 1% as the wavelength increased from 1275 to 6900 Angstrom These data do not probe extreme ultraviolet (1200 Angstrom to 0.1 keV) or hard X-ray (2-50 keV) variability. The phase differences between variations in different bands were consistent with zero lag, with upper limits of less than or similar to 0.15 day between 1275 Angstrom and the other ultraviolet bands, less than or similar to 0,3 day between 1275 Angstrom and 1.5 keV, and less than or similar to 1 day between 1275 and 5125 Angstrom These tight limits represent more than an order of magnitude improvement over those determined in previous multi-wave-band AGN monitoring campaigns. The ultraviolet fluctuation power spectra showed no evidence for periodicity, but were instead well fitted with a very steep, red power law (a less than or equal to -2.5). If photons emitted at a ''primary'' wave band are absorbed by nearby material and ''reprocessed'' to produce emission at a secondary wave band, causality arguments require that variations in the secondary band follow those in the primary band. The tight interband correlation and limits on the ultraviolet and medium-energy X-ray lags indicate that the reprocessing region is smaller than similar to 0.15 it-day in size. After correcting for strong (a factor of greater than or similar to 15) line-of-sight absorption, the medium-energy X-ray luminosity variations appear adequate to drive the ultraviolet/optical variations. However, the medium-energy X-ray NVA is 2-4 times that in the ultraviolet, and the single-epoch, absorption-corrected X-ray/gamma-ray luminosity is only about one-third of that of the ultraviolet/optical/infrared, suggesting that at most about a third of the total low-energy flux could be reprocessed high-energy emission. The strong wavelength dependence of the ultraviolet NVAs is consistent with an origin in an accretion disk, with the variable emission coming from the hotter inner regions and nonvariable emission from the cooler outer regions. These data, when combined with the results of disk fits, indicate a boundary between these regions near a radius of order R approximate to 0.07 1t-day. No interband lag would be expected, as reprocessing (and thus propagation between regions) need not occur, and the orbital timescale of similar to 1 day is consistent with the observed variability timescale. However, such a model does not immediately explain the good correlation between ultraviolet and X-ray variations. C1 TEL AVIV UNIV,SACKLER FAC EXACT SCI,SCH PHYS & ASTRON,IL-69978 TEL AVIV,ISRAEL. TEL AVIV UNIV,SACKLER FAC EXACT SCI,WISE OBSERV,IL-69978 TEL AVIV,ISRAEL. NASA,GODDARD SPACE FLIGHT CTR,ASTRON PROGRAM,COMP SCI CORP,GREENBELT,MD 20771. UNIV CALIF LOS ANGELES,DEPT ASTRON,LOS ANGELES,CA 90024. OHIO STATE UNIV,DEPT ASTRON,COLUMBUS,OH 43210. UNIV LEICESTER,DEPT ASTRON,LEICESTER LE1 7RH,LEICS,ENGLAND. EUROPEAN SPACE AGCY,ISO PROJECT,MADRID 28080,SPAIN. UNIV ST ANDREWS,SCH PHYS & ASTRON,ST ANDREWS KY16 9SS,FIFE,SCOTLAND. UNIV KENTUCKY,DEPT PHYS & ASTRON,LEXINGTON,KY 40506. JOHNS HOPKINS UNIV,DEPT PHYS & ASTRON,BALTIMORE,MD 21218. NASA,GODDARD SPACE FLIGHT CTR,HIGH ENERGY PHYS LAB,GREENBELT,MD 20771. UNIV COLORADO,CTR ASTROPHYS & SPACE ASTRON,BOULDER,CO 80309. UNIV STERNWARTE GOTTINGEN,D-37083 GOTTINGEN,GERMANY. CTR ETUD SACLAY,SERV ASTROPHYS,F-91191 GIF SUR YVETTE,FRANCE. COLGATE UNIV,DEPT PHYS & ASTRON,HAMILTON,NY 13346. LOWELL OBSERV,FLAGSTAFF,AZ 86001. UNIV CALIF BERKELEY,SPACE SCI LAB,BERKELEY,CA 94720. EUREKA SCI INC,OAKLAND,CA. UNIV SCI & TECHNOL,CTR ASTROPHYS,HEFEI,ANHUI,PEOPLES R CHINA. CRIMEAN ASTROPHYS OBSERV,UA-334413 NAUCHNYI,CRIMEA,UKRAINE. LANDESSTERNWARTE KONIGSTUHL,D-69117 HEIDELBERG,GERMANY. UNIV NACL AUTONOMA MEXICO,INST ASTRON,MEXICO CITY 04510,DF,MEXICO. UNIV NEBRASKA,DEPT PHYS & ASTRON,LINCOLN,NE 68588. S AFRICAN ASTRON OBSERV,ZA-7935 CAPE TOWN,SOUTH AFRICA. SPACE TELESCOPE SCI INST,BALTIMORE,MD 21218. HARVARD SMITHSONIAN CTR ASTROPHYS,CAMBRIDGE,MA 02138. DOMINION ASTROPHYS OBSERV,VICTORIA,BC V8X 4M6,CANADA. USN,RES LAB,WASHINGTON,DC 20375. TECHNION ISRAEL INST TECHNOL,DEPT PHYS,IL-32000 HAIFA,ISRAEL. UNIV MICHIGAN,DEPT ASTRON,ANN ARBOR,MI 48109. JAGIELLONIAN UNIV,ASTRON OBSERV,PL-30244 KRAKOW,POLAND. UNIV TORONTO,CANADIAN INST THEORET ASTROPHYS,TORONTO,ON M5S 1A1,CANADA. GEORGIA STATE UNIV,DEPT PHYS & ASTRON,ATLANTA,GA 30303. MOSCOW MV LOMONOSOV STATE UNIV,STERNBERG ASTRON INST,MOSCOW 119899,RUSSIA. UNIV CALGARY,DEPT PHYS & ASTRON,CALGARY,AB T2N 1N4,CANADA. MT ROYAL COLL,DEPT ENGN MATH & PHYS,CALGARY,AB T3E 6K6,CANADA. UNIV ROMA LA SAPIENZA,IST ASTRON,I-00161 ROME,ITALY. BOWLING GREEN STATE UNIV,DEPT PHYS & ASTRON,BOWLING GREEN,OH 43403. CHINESE ACAD SCI,SHANGHAI OBSERV,SHANGHAI,PEOPLES R CHINA. UNIV OVIEDO,FAC CIENCIAS,DEPT FIS,OVIEDO,ASTURIAS,SPAIN. INST ASTROFIS CANARIAS,E-38200 LA LAGUNA,TENERIFE,SPAIN. ESA,IUE OBSERV,MADRID 28080,SPAIN. UNIV EDINBURGH,ROYAL OBSERV EDINBURGH,EDINBURGH EH9 3HJ,MIDLOTHIAN,SCOTLAND. INST ASTROPHYS,F-75014 PARIS,FRANCE. AGNES SCOTT COLL,DEPT PHYS & ASTRON,DECATUR,GA 30030. AGNES SCOTT COLL,BRADLEY OBSERV,DECATUR,GA 30030. ROYAL GREENWICH OBSERV,CAMBRIDGE CB3 0EZ,ENGLAND. LAEFF,E-28080 MADRID,SPAIN. UNIV ARIZONA,STEWARD OBSERV,TUCSON,AZ 85726. UNIV COLORADO,JILA,BOULDER,CO 80309. NATL INST STAND & TECHNOL,BOULDER,CO 80309. IRAM,F-38046 ST MARTIN DHERES,FRANCE. OSSERVATORIO ASTRON BOLOGNA,I-40126 BOLOGNA,ITALY. NATL CENT UNIV,INST ASTRON,CHUNGLI 32054,TAIWAN. EUROPEAN SO OBSERV,D-85748 GARCHING,GERMANY. ASTRON OBSERV,S-75120 UPPSALA,SWEDEN. UNIV KEELE,DEPT PHYS,KEELE ST5 5BG,STAFFS,ENGLAND. CARNEGIE INST WASHINGTON OBSERV,PASADENA,CA 91101. CHINESE ACAD SCI,BEIJING ASTRON OBSERV,BEIJING 100080,PEOPLES R CHINA. NICHOLAS COPERNICUS ASTRON CTR,PL-00716 WARSAW,POLAND. RP Edelson, RA (reprint author), UNIV IOWA,DEPT PHYS & ASTRON,203 VAN ALLEN,IOWA CITY,IA 52242, USA. RI Morris, Simon/G-7981-2011; Oknyanskij, Victor/I-9267-2012; Johnson, Neil/G-3309-2014; Recondo, Carmen/B-1215-2012; Stirpe, Giovanna/O-9393-2015; OI Morris, Simon/0000-0003-4866-110X; Recondo, Carmen/0000-0001-9813-6798; Stirpe, Giovanna/0000-0002-3702-8731; Gaskell, C/0000-0003-4888-2009; Wilkes, Belinda/0000-0003-1809-2364; Perez, Enrique/0000-0001-9737-4559 NR 64 TC 141 Z9 144 U1 0 U2 7 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 10 PY 1996 VL 470 IS 1 BP 364 EP 377 DI 10.1086/177872 PN 1 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VL723 UT WOS:A1996VL72300028 ER PT J AU Zecchini, F Vecchione, M Roper, CFE AF Zecchini, F Vecchione, M Roper, CFE TI A quantitative comparison of hectocotylus morphology between Mediterranean and western Atlantic populations of the squid Illex coindetii (Mollusca: Cephalopoda: Oegopsida: Ommastrephidae) SO PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON LA English DT Article AB Geographic variation in morphology of the commercially important squid species Illex coindetii has led to speculation about possible taxonomic differences among populations. We compared hectocotylus morphology between western Atlantic specimens, from the Gulf of Mexico and Caribbean, and Mediterranean specimens, from the Tyrrhenian Sea. Although a few differences were found in morphometrics and meristics, we conclude that the two populations are conspecific. C1 NATL MUSEUM NAT HIST,NATL MARINE FISHERIES SERV,WASHINGTON,DC 20560. SMITHSONIAN INST,NATL MUSEUM NAT HIST,DEPT INVERTEBRATE ZOOL MOLLUSKS,WASHINGTON,DC 20560. RP Zecchini, F (reprint author), UNIV PISA,DIPARTIMENTO SCI AMBIENTE TERRITORIO,VIA VOLTA 6,I-56126 PISA,ITALY. NR 11 TC 6 Z9 6 U1 0 U2 0 PU BIOL SOC WASHINGTON PI WASHINGTON PA NAT MUSEUM NAT HIST SMITHSONIAN INST, WASHINGTON, DC 20560 SN 0006-324X J9 P BIOL SOC WASH JI Proc. Biol. Soc. Wash. PD OCT 9 PY 1996 VL 109 IS 3 BP 591 EP 599 PG 9 WC Biology SC Life Sciences & Biomedicine - Other Topics GA VM334 UT WOS:A1996VM33400019 ER PT J AU Meyer, H Leone, SR AF Meyer, H Leone, SR TI Preparation and probing of alignment in molecular ensembles by saturated coherent pulsed laser excitation SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID COUNTERPROPAGATING BEAM SCATTERING; INDUCED FLUORESCENCE MEASUREMENTS; 2-PHOTON NONRESONANT EXCITATION; STIMULATED RAMAN-SCATTERING; ROTATIONAL ALIGNMENT; VECTOR CORRELATIONS; REACTION-PRODUCTS; POPULATION TRANSFER; SUB-DOPPLER; POLARIZATION AB An analytical solution of the optical Bloch equations for a degenerate two-level system is presented for coherent excitation with a monochromatic light pulse of rectangular time profile and linear polarization including off-resonance interaction. The generalization to an arbitrary excitation and detection geometry is achieved by incorporation of the appropriate coordinate frame rotations. In this way the formalism can be applied to the determination of alignment parameters in molecular ensembles even under partially saturated conditions. In the limit of linear absorption the results reduce to those obtained by Greene and Zare [J. Chem. Phys. 78, 6741 (1983)]. For complete saturation on lines of a Q or R branch, polarized fluorescence detection is sensitive only to the quadrupole alignment moment. The formalism also allows investigation of the production of aligned ensembles via coherent optical pumping with a single pulse. Depending on the degree of saturation as well as the detuning from resonance, strong alignment can be created. (C) 1996 American Institute of Physics. C1 NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. UNIV COLORADO,DEPT CHEM ENGN,BOULDER,CO 80309. RP Meyer, H (reprint author), UNIV GEORGIA,DEPT PHYS & ASTRON,ATHENS,GA 30602, USA. NR 55 TC 7 Z9 7 U1 2 U2 6 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD OCT 8 PY 1996 VL 105 IS 14 BP 5858 EP 5871 DI 10.1063/1.472427 PG 14 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VL696 UT WOS:A1996VL69600020 ER PT J AU Stoffel, NC Dai, CA Kramer, EJ Russell, TP Deline, V Volksen, W Wu, WL Satija, S AF Stoffel, NC Dai, CA Kramer, EJ Russell, TP Deline, V Volksen, W Wu, WL Satija, S TI High-resolution profiling of the polyimide-polyimide interface SO MACROMOLECULES LA English DT Article ID POLY(AMIC ACID); IMIDIZATION; BEHAVIOR; INTERDIFFUSION; PRECURSOR; ADHESION; FILMS AB Dynamic secondary ion mass spectrometry (SIMS), nuclear reaction analysis, and neutron reflectometry were used to profile polyimide-polyimide interfaces. For interfaces between two layers of poly(4,4'-oxydiphenylene-pyromellitimide) (PMDA-ODA) polyimide it was determined that the interfacial fracture energy G(c) and the interfacial width depended primarily upon the imide fraction, f, of the base layer. For f <0.9, there was a sharp interface between the deuterium-labeled poly(amic acid ethyl ester) (dPAE) and the base layer with a long low volume fraction tail of dPAE penetrating into the base layer. The volume fraction of the penetrant was limited by the imide fraction of the base layer and approached zero for f > 0.9. The PMDA-ODA/PMDA-ODA interface formed with a fully imidized base layer was similar to 30 Angstrom in width, whereas that formed when f = 0.9 was similar to 80 Angstrom in width. The interface formed during the spin-casting process did not broaden significantly after annealing at 400 degrees C. We also investigated the interface between a more flexible thermoplastic polyimide poly(4,4'-oxydiphenylene-oxydiphthalimide) (ODPA-ODA) and a fully imidized PMDA-ODA layer. The shape of the ODPA-ODA/PMDA-ODA interface was found to depend upon annealing temperature. Unannealed samples and samples annealed at 350 degrees C could be fit with an error function, and the interfacial width was similar to 50 Angstrom. Samples annealed at 400 and 450 degrees C were best fit by a fairly sharp interfacial profile with ODPA-ODA tails proceeding into the PMDA-ODA layer. The volume fraction of the ODPA-ODA in the PMDA-ODA depended upon the annealing temperature T-ann. The G(c) of the ODPA-ODA/PMDA-ODA interface appears limited by the solubility of ODPA-ODA in PMDA-ODA. C1 IBM CORP,ALMADEN RES CTR,SAN JOSE,CA 95120. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RP Stoffel, NC (reprint author), CORNELL UNIV,DEPT MAT SCI & ENGN,ITHACA,NY 14853, USA. NR 27 TC 13 Z9 13 U1 1 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD OCT 7 PY 1996 VL 29 IS 21 BP 6880 EP 6891 DI 10.1021/ma9601880 PG 12 WC Polymer Science SC Polymer Science GA VL631 UT WOS:A1996VL63100029 ER PT J AU Williams, KL Sander, LC Wise, SA AF Williams, KL Sander, LC Wise, SA TI Comparison of liquid and supercritical fluid chromatography using naphthylethylcarbamoylated-beta-cyclodextrin chiral stationary phases SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article DE chiral stationary phases, LC; chiral stationary phases, SFC; enantiomer separation; cyclodextrins ID PACKED-COLUMNS; BONDED PHASES; RESOLUTION; ENANTIOMERS; SEPARATION; DERIVATIVES; HPLC; SFC AB A comparison of liquid (LC) and sub- or supercritical fluid chromatography (SFC) was performed using naphthylethylcarbamoylated-beta-cyclodextrin chiral stationary phases (NEC-CD CSPs). Compounds resolved in the normal-phase, reversed-phase and polar organic modes on the NEC-CD CSPs in LC were also separated on the same columns in SFC with a carbon dioxide-alcohol eluent. Advantages of SFC for chiral separations on these CSPs included simple eluents, rapid optimization of selectivity and improved resolution compared to LC results for the same columns. The effect of alcohol modifier was also investigated and the results provided insights into the chiral recognition mechanisms in SFC. The versatility of the NEC-CD CSPs in SFC was demonstrated by performing separations representative of the three distinct mobile phase modes in LC in a single analysis in SFC. RP Williams, KL (reprint author), NATL INST STAND & TECHNOL,DIV ANALYT CHEM,CHEM SCI & TECHNOL LAB,GAITHERSBURG,MD 20899, USA. NR 29 TC 34 Z9 35 U1 1 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0021-9673 J9 J CHROMATOGR A JI J. Chromatogr. A PD OCT 4 PY 1996 VL 746 IS 1 BP 91 EP 101 DI 10.1016/0021-9673(96)00291-9 PG 11 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA VM827 UT WOS:A1996VM82700011 ER PT J AU Kamna, MM Stranick, SJ Weiss, PS AF Kamna, MM Stranick, SJ Weiss, PS TI Imaging substrate-mediated interactions SO SCIENCE LA English DT Article ID METAL-SURFACE; GAS; ELECTRONS; DYNAMICS; BENZENE; STEPS C1 NIST,SURFACE & MICROANAL DIV,GAITHERSBURG,MD 20899. RP Kamna, MM (reprint author), PENN STATE UNIV,DEPT CHEM,UNIVERSITY PK,PA 16802, USA. RI Weiss, Paul/A-2575-2011 OI Weiss, Paul/0000-0001-5527-6248 NR 13 TC 62 Z9 62 U1 1 U2 17 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD OCT 4 PY 1996 VL 274 IS 5284 BP 118 EP 119 DI 10.1126/science.274.5284.118 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA VK748 UT WOS:A1996VK74800064 ER PT J AU Wallace, E Wallnau, KC AF Wallace, E Wallnau, KC TI A situated evaluation of the Object Management Group's (OMG) Object Management Architecture (OMA) SO ACM SIGPLAN NOTICES LA English DT Article; Proceedings Paper CT 1996 ACM SIGPAN Conference on Object-Oriented Programming Systems, Languages and Applications (OOPSLA 96) CY OCT 06-10, 1996 CL SAN JOSE, CA SP ACM SIGPLAN AB it has been difficult to objectively assess the real value or maturity of the Object Management Group's Object Management Architecture (OMA). While experience reports have appeared in the literature these have focused more on the functionality of the end-system than on systematically exploring the strengths and weaknesses of the OMA, and providing practical guidelines on the effective use of the OMA for specific software-engineering problems. In this paper we describe a case study in the use of the OMA to integrate legacy software are components into a distributed object system. We assess the OMA in this problem context, and indicate strengths and weaknesses of the specification and current implementations. We extrapolate our experience to a broader class of component-based software systems, and recommend an architectural strategy for the effective use of the OMA to this class of systems. C1 CARNEGIE MELLON UNIV,INST SOFTWARE ENGN,PITTSBURGH,PA 15213. RP Wallace, E (reprint author), NATL INST STAND & TECHNOL,MFG ENGN LAB,GAITHERSBURG,MD 20899, USA. NR 15 TC 3 Z9 3 U1 0 U2 0 PU ASSOC COMPUTING MACHINERY PI NEW YORK PA 1515 BROADWAY, NEW YORK, NY 10036 SN 0362-1340 J9 ACM SIGPLAN NOTICES JI ACM Sigplan Not. PD OCT PY 1996 VL 31 IS 10 BP 168 EP 178 DI 10.1145/236338.236353 PG 11 WC Computer Science, Software Engineering SC Computer Science GA VR082 UT WOS:A1996VR08200014 ER PT J AU Hobbie, EK Sung, LP AF Hobbie, EK Sung, LP TI Rayleigh-Gans scattering from polydisperse colloidal suspensions SO AMERICAN JOURNAL OF PHYSICS LA English DT Article ID DYNAMICS; SYSTEM AB The scattering of polarized light from a collection of dielectric spheres with model disorder in the particle dimensions is derived in the first Born approximation. The paper is intended as a brief pedagogical review of some of the essential physics behind static light scattering from complex fluids, and attempts to elucidate the natural emergence of the statistical-structure and form factors while emphasizing the role of polydispersity in the particle size, The criterion for the convergence of the Born series is examined. The problem is cast in the language of Fourier transforms and correlation functions at a level that should be accessible to advanced undergraduates. (C) 1996 American Association of Physics Teachers. C1 NIST,DIV POLYMERS,GAITHERSBURG,MD 20899. RP Hobbie, EK (reprint author), UNIV WISCONSIN,DEPT PHYS & ASTRON,RIVER FALLS,WI 54022, USA. RI Hobbie, Erik/C-8269-2013 NR 14 TC 10 Z9 10 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0002-9505 J9 AM J PHYS JI Am. J. Phys. PD OCT PY 1996 VL 64 IS 10 BP 1298 EP 1303 DI 10.1119/1.18467 PG 6 WC Education, Scientific Disciplines; Physics, Multidisciplinary SC Education & Educational Research; Physics GA VL181 UT WOS:A1996VL18100020 ER PT J AU Roberts, MA LocascioBrown, L MacCrehan, WA Durst, RA AF Roberts, MA LocascioBrown, L MacCrehan, WA Durst, RA TI Liposome behavior in capillary electrophoresis SO ANALYTICAL CHEMISTRY LA English DT Article ID FLUORESCENCE; IMMUNOASSAY; VESICLES; FUSION; ERYTHROCYTE; ALACHLOR; CELLS; FIELD AB The behavior of liposomes in capillary electrophoresis is studied for the purpose of developing a potential method for characterizing liposomes prepared for use in industrial and analytical applications. This study characterizes the electrophoretic behavior of liposomes under various conditions to provide information about electrophoretic mobility and liposome-capillary surface interactions, The results of this method are compared with the results obtained using traditional laser light-scattering methods to obtain size information about liposome preparations. Additionally, reactions of liposomes and the surfactant n-octyl-beta-D-glucopyranoside are performed off-line in bulk solution experiments and on-line in the capillary. Automated delivery of lysis agents by multiple electrokinetic injections is demonstrated as a general method for inducing on-capillary reactions between liposomes and other reagents. Furthermore, some preliminary evidence on the use of liposomes as a hydrophobic partitioning medium for analytical separations is presented. C1 NATL INST STAND & TECHNOL,CHEM SENSING & AUTOMAT TECHNOL GRP,DIV ANALYT CHEM,GAITHERSBURG,MD 20899. CORNELL UNIV,INST COMPARAT & ENVIRONM TOXICOL,BIOANALYT LAB,GENEVA,NY 14456. NR 24 TC 59 Z9 59 U1 1 U2 15 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD OCT 1 PY 1996 VL 68 IS 19 BP 3434 EP 3440 DI 10.1021/ac9603284 PG 7 WC Chemistry, Analytical SC Chemistry GA VK590 UT WOS:A1996VK59000028 PM 21619277 ER PT J AU VanGorkom, JH Carilli, CL Stocke, JT Perlman, ES Shull, JM AF VanGorkom, JH Carilli, CL Stocke, JT Perlman, ES Shull, JM TI The H I environment of nearby Lyman-alpha absorbers SO ASTRONOMICAL JOURNAL LA English DT Article ID ABSORPTION-LINES; DARK-MATTER; GALACTIC HALO; PRESENT EPOCH; LOW-REDSHIFT; GALAXIES; ORIGIN; FOREST; CLOUDS; POPULATION AB We present the results of a VLA and WSRT search for H I emission from the vicinity of seven nearby clouds, which were observed in Ly alpha absorption with HST toward Mrk 335, Mrk 501, and PKS 2155-304. Around the absorbers, we searched a volume of 40' x 40' x 1000 km s(-1); for one of the absorbers we probed a velocity range of only 600 km s(-1). The H I mass sensitivity (5 sigma) very close to the lines of sight varies from 5 x 10(6) M. at best to 5 x 10(8) M. at worst. We detected H I emission in the vicinity of four out of seven absorbers. The closest galaxy we find to the absorbers is a small dwarf galaxy at a projected distance of 68h(-1) kpc from the sight line toward Mrk 335. This optically uncataloged galaxy has the same velocity (V = 1970 km s(-1)) as one of the absorbers, is fainter than the SMC, and has an H I mass of only 4 x 10(7) M.. We found a somewhat more luminous galaxy at exactly the velocity (V = 5100 km s(-1)) of one of the absorbers toward PKS 2155-304 at a projected distance of 230h(-1) kpc from the sight line, Two other, stronger absorbers toward PKS 2155-304 at V approximate to 17 000 km s(-1) appear to be associated with a loose group of three bright spiral galaxies, at projected distances of 300 to 600h(-1) kpc. These results support the conclusions emerging from optical searches that most nearby Ly alpha forest clouds trace the large-scale structures outlined by the optically luminous galaxies, although this is still based on small-number statistics. We do not find any evidence from the H I distribution or kinematics that there is a physical association between an absorber and its closest galaxy. While the absorbing clouds are at the systemic velocity of the galaxies, the H I extent of the galaxies is fairly typical, and at least an order of magnitude smaller than the projected distance to the sight line at which the absorbers are seen. On the other hand, we also do not find evidence against such a connection. In total, we detected H I emission from five galaxies, of which two were previously uncataloged and one did not have a known redshift. No H I emission was detected from the vicinity of the two absorbers, which are located in a void and a region of very low galaxy density; but the limits are somewhat less stringent than for the other sight lines. These results are similar to what has been found in optically unbiased H I surveys. Thus, the presence of Ly alpha absorbers does not significantly alter the H I detection rate in their environment. (C) 1996 American Astronomical Society. C1 NATL RADIO ASTRON OBSERV, SOCORRO, NM 87801 USA. UNIV COLORADO, DEPT ASTROPHYS PLANETARY & ATMOSPHER SCI, CTR ASTROPHYS & SPACE ASTRON, BOULDER, CO 80309 USA. UNIV COLORADO, JILA, BOULDER, CO 80309 USA. NATL INST STAND & TECHNOL, BOULDER, CO 80303 USA. RP VanGorkom, JH (reprint author), COLUMBIA UNIV, DEPT ASTRON, NEW YORK, NY 10027 USA. NR 53 TC 34 Z9 34 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-6256 J9 ASTRON J JI Astron. J. PD OCT PY 1996 VL 112 IS 4 BP 1397 EP 1408 DI 10.1086/118107 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VK840 UT WOS:A1996VK84000003 ER PT J AU Meyers, TP Hall, ME Lindberg, SE Kim, K AF Meyers, TP Hall, ME Lindberg, SE Kim, K TI Use of the modified Bowen-ratio technique to measure fluxes of trace gases SO ATMOSPHERIC ENVIRONMENT LA English DT Article ID AIR-SURFACE EXCHANGE; DRY DEPOSITION; VOLATILE MERCURY; DECIDUOUS FOREST; PLANT CANOPY; NITRIC-ACID; VAPOR; RATES; SOIL AB The modified Bowen-ratio (MBR) technique is a micrometeorological method that can be used to estimate air-surface exchange rates, providing differences in concentrations between two heights can be resolved. Application of the MBR method requires that fluxes and gradients for at least one scalar entity be measured in order to directly compute the exchange coefficient k, which is assumed to be applicable for all scalars. Direct measurements of fluxes (eddy correlation) and gradients for CO2 and H2O were made during three experiments. Measurements were made at the forest floor of a boreal forest, over a lake surface, and at the forest floor of a leafless deciduous forest. Data from these experiments were used to examine the equality of H2O and CO2 exchange coefficients. The mean difference between the exchange coefficients for CO2 and H2O was not found to be statistically different from zero. Uncertainties in the determination of k associated with gradient measurements and sampling strategies are evaluated. The MBR technique is then used to assess the air-surface exchange rates of gas-phase mercury. Although the acceptably good agreement between the exchange coefficients for CO2 and H2O does not prove they are equal to k for Hg, greater confidence is assumed in the determination of Hg fluxes than just using k for heat. Copyright (C) 1996 Published by Elsevier Science Ltd C1 OAK RIDGE ASSOCIATED UNIV, OAK RIDGE, TN USA. OAK RIDGE NATL LAB, DIV ENVIRONM SCI, OAK RIDGE, TN 37831 USA. KOREA NATL UNIV EDUC, DEPT ENVIRONM SCI, KOREA CHINA CTR ATMOS RES, CHOONGBUK 363391, SOUTH KOREA. RP Meyers, TP (reprint author), NOAA, ATMOSPHER TURBULENCE & DIFFUS DIV, POB 2456, OAK RIDGE, TN 37831 USA. RI Meyers, Tilden/C-6633-2016 NR 37 TC 70 Z9 73 U1 1 U2 14 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1352-2310 J9 ATMOS ENVIRON JI Atmos. Environ. PD OCT PY 1996 VL 30 IS 19 BP 3321 EP 3329 DI 10.1016/1352-2310(96)00082-9 PG 9 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA VB161 UT WOS:A1996VB16100009 ER PT J AU Prospero, JM Barrett, K Church, T Dentener, F Duce, RA Galloway, JN Levy, H Moody, J Quinn, P AF Prospero, JM Barrett, K Church, T Dentener, F Duce, RA Galloway, JN Levy, H Moody, J Quinn, P TI Atmospheric deposition of nutrients to the North Atlantic Basin SO BIOGEOCHEMISTRY LA English DT Article DE dust; deposition; iron; models; NHx; NOy; nutrients ID FOSSIL-FUEL COMBUSTION; GENERAL-CIRCULATION MODEL; MINERAL AEROSOL SOLUTIONS; SAHARAN DUST; TRACE-ELEMENTS; PACIFIC-OCEAN; ICE-CORE; PRECIPITATION CHEMISTRY; PHYTOPLANKTON GROWTH; GLOBAL EMISSIONS AB Atmospheric chemical models are used to estimate the deposition rate of various inorganic oxides of nitrogen (NOy), reduced nitrogen species (NHx) and mineral dust to the North Atlantic Ocean (NAG). The estimated deposition of NOy to the NAO (excluding the coastal ocean) and the Caribbean is 360 x 10(9) Moles-N m(-2) yr(-1) (5.0 Tg N); this is equivalent to about 13% of the estimated global emission rate (natural and anthropogenic) and a quarter of the emission rate from sources in North America and Europe. In the case of NHx, 258 Moles-N m(-2) yr(-1) (3.6 Tg N) are deposited to the NAO and the Caribbean; this is about 6% of the global continental emissions. There is relatively little data on the deposition rate of organic nitrogen species; nonetheless, this evidence suggests that concentrations and deposition rates are comparable to those for inorganic nitrogen. Because of anthropogenic emissions, the present-day deposition rate of NOy to the NAO is about five times greater than pre-industrial times largely due to emissions from energy production and biomass burning. The present-day emissions of NHx from continental anthropogenic sources are about four-to-five times greater than natural sources, mostly due to the impact of emissions from animal wastes associated with food production. Indeed, present-day emissions of NHx from animal waste are estimated to be about 10 times greater than the pre-human era. The deposition rate of mineral dust to the NAO is about 170 Tg yr(-1); deposited with the dust (assuming average crustal abundances) is about 6 Tg yr(-1) of Fe and 0.2 Tg yr(-1) of P. Dust deposition in the NAO is almost completely attributable to transport from North African sources; a substantial fraction of the dust over the NAO is probably mobilized as a consequence of land use practices in arid regions and, consequently, it should be regarded as a pollutant. C1 NORWEGIAN METEOROL INST, OSLO, NORWAY. UNIV DELAWARE, COLL MARINE STUDIES, NEWARK, DE USA. AGR UNIV WAGENINGEN, DEPT AIR QUAL, WAGENINGEN, NETHERLANDS. TEXAS A&M UNIV, COLL GEOSCI & MARITIME STUDIES, COLLEGE STN, TX USA. UNIV VIRGINIA, DEPT ENVIRONM SCI, CHARLOTTESVILLE, VA 22903 USA. PRINCETON UNIV, NOAA, GEOPHYS FLUID DYNAM LAB, PRINCETON, NJ 08542 USA. UNIV VIRGINIA, DEPT ENVIRONM SCI, CHARLOTTESVILLE, VA 22903 USA. NOAA, PACIFIC MARINE ENVIRONM LAB, SEATTLE, WA 98115 USA. RP Prospero, JM (reprint author), UNIV MIAMI, ROSENSTIEL SCH MARINE & ATMOSPHER SCI, 4600 RICKENBACKER CAUSEWAY, MIAMI, FL 33149 USA. RI Duce, Robert/A-9917-2010; Galloway, James/C-2769-2013; Quinn, Patricia/R-1493-2016; OI Galloway, James/0000-0001-7676-8698; Quinn, Patricia/0000-0003-0337-4895; Prospero, Joseph/0000-0003-3608-6160 NR 139 TC 224 Z9 237 U1 5 U2 40 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0168-2563 J9 BIOGEOCHEMISTRY JI Biogeochemistry PD OCT PY 1996 VL 35 IS 1 BP 27 EP 73 DI 10.1007/BF02179824 PG 47 WC Environmental Sciences; Geosciences, Multidisciplinary SC Environmental Sciences & Ecology; Geology GA VU200 UT WOS:A1996VU20000003 ER PT J AU Nixon, SW Ammerman, JW Atkinson, LP Berounsky, VM Billen, G Boicourt, WC Boynton, WR Church, TM Ditoro, DM Elmgren, R Garber, JH Giblin, AE Jahnke, RA Owens, NJP Pilson, MEQ Seitzinger, SP AF Nixon, SW Ammerman, JW Atkinson, LP Berounsky, VM Billen, G Boicourt, WC Boynton, WR Church, TM Ditoro, DM Elmgren, R Garber, JH Giblin, AE Jahnke, RA Owens, NJP Pilson, MEQ Seitzinger, SP TI The fate of nitrogen and phosphorus at the land sea margin of the North Atlantic Ocean SO BIOGEOCHEMISTRY LA English DT Article DE continental shelf; estuaries; mass balance; nitrogen; North Atlantic; nutrient budget; phosphorus ID ORGANIC-CARBON ACCUMULATION; AMAZON CONTINENTAL-SHELF; MARINE ECOSYSTEMS; SEDIMENT ACCUMULATION; MISSISSIPPI RIVER; NUTRIENT INPUTS; SCOTIAN SHELF; MASS-BALANCE; FRESH-WATER; NEW-ENGLAND AB Five large rivers that discharge on the western North Atlantic continental shelf carry about 45% of the nitrogen (N) and 70% of the phosphorus (P) that others estimate to be the total flux of these elements from the entire North Atlantic watershed, including North, Central and South America, Europe, and Northwest Africa. We estimate that 61 . 10(9) moles y(-1) of N and 20 . 10(9) moles y(-1) of P from the large rivers are buried with sediments in their deltas, and that an equal amount of N and P from the large rivers is lost to the shelf through burial of river sediments that are deposited directly on the continental slope. The effective transport of active N and P from land to the shelf through the very large rivers is thus reduced to 292 . 10(9) moles y(-1) of N and 13 . 10(9) moles y(-1) of P. The remaining riverine fluxes from land must pass through estuaries. An analysis of annual total N and total P budgets for various estuaries around the North Atlantic revealed that the net fractional transport of these nutrients through estuaries to the continental shelf is inversely correlated with the log mean residence time of water in the system. This is consistent with numerous observations of nutrient retention and loss in temperate lakes. Denitrification is the major process responsible for removing N in most estuaries, and the fraction of total N input that is denitrified appears to be directly proportional to the log mean water residence time. In general, we estimate that estuarine processes retain and remove 30-65% of the total N and 10-55% of the total P that would otherwise pass into the coastal ocean. The resulting transport through estuaries to the shelf amounts to 172-335 . 10(9) moles y(-1) of N and 11-19 . 10(9) moles y(-1) of P. These values are similar to the effective contribution from the large rivers that discharge directly on the shelf. For the North Atlantic shelf as a whole, N fluxes from major rivers and estuaries exceed atmospheric deposition by a factor of 3.5-4.7, but this varies widely among regions of the shelf. For example, on the U.S. Atlantic shelf and on the northwest European shelf, atmospheric deposition of N may exceed estuarine exports. Denitrification in shelf sediments exceeds the combined N input from land and atmosphere by a factor of 1.4-2.2. This deficit must be met by a flux of N from the deeper ocean. Burial of organic matter fixed on the shelf removes only a small fraction of the total N and P input (2-12% of N from land and atmosphere; 1-17% of P), but it may be a significant loss for P in the North Sea and some other regions. The removal of N and P in fisheries landings is very small. The gross exchange of N and P between the shelf and the open ocean is much lager than inputs from land and, for the North Atlantic shelf as a whole, it may be much larger than the N and P removed through denitrification, burial, and fisheries. Overall, the North Atlantic continental shelf appears to remove some 700-950 . 10(9) moles of N each year from the deep ocean and to transport somewhere between 18 and 30 . 10(9) moles of P to the open sea. If the N and P associated with riverine sediments deposited on the continental slope are included in the total balance, the net flux of N to the shelf is reduced by 60 . 10(9) moles y(-1) and the P flux to the ocean is increased by 20 . 10(9) moles y(-1). These conclusions are quite tentative. however, because of large uncertainties in our estimates of some important terms in the shelf mass balance. C1 TEXAS A&M UNIV, COLLEGE STN, TX 77843 USA. OLD DOMINION UNIV, NORFOLK, VA 23529 USA. FREE UNIV BRUSSELS, B-1050 BRUSSELS, BELGIUM. UNIV MARYLAND, COLLEGE PK, MD 20742 USA. UNIV DELAWARE, NEWARK, DE 19716 USA. MANHATTAN COLL, BRONX, NY USA. UNIV STOCKHOLM, S-10691 STOCKHOLM, SWEDEN. US EPA, WASHINGTON, DC 20460 USA. BIOL MARINE LAB, WOODS HOLE, MA USA. SKIDAWAY INST OCEANOG, SAVANNAH, GA 31406 USA. UNIV NEWCASTLE, NEWCASTLE, NSW 2308, AUSTRALIA. RUTGERS STATE UNIV, NOAA, CMER PROGRAM, PISCATAWAY, NJ 08855 USA. RP Nixon, SW (reprint author), UNIV RHODE ISL, KINGSTON, RI 02881 USA. RI Wood, Chris/I-5638-2012; Elmgren, Ragnar/A-1854-2013; Ross, Donald/F-7607-2012; Owens, Nicholas/B-6639-2015 OI Ross, Donald/0000-0002-8659-3833; Owens, Nicholas/0000-0003-4245-5858 NR 128 TC 483 Z9 502 U1 19 U2 148 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0168-2563 J9 BIOGEOCHEMISTRY JI Biogeochemistry PD OCT PY 1996 VL 35 IS 1 BP 141 EP 180 DI 10.1007/BF02179826 PG 40 WC Environmental Sciences; Geosciences, Multidisciplinary SC Environmental Sciences & Ecology; Geology GA VU200 UT WOS:A1996VU20000005 ER PT J AU Pilson, MEQ Seitzinger, SP AF Pilson, MEQ Seitzinger, SP TI Areas of shallow water in the North Atlantic SO BIOGEOCHEMISTRY LA English DT Article; Proceedings Paper CT Workshop on Nitrogen Cycling in the North Atlantic Ocean and Its Watersheds CY MAY, 1994 CL BLOCK ISLAND, RI SP Sci Comm Problems Environm, Int Council Sci Unions DE area; continental shelves; North Atlantic; shallow water AB We report here estimates of the areas of water that are between 1 and 100 m and between 1 and 200 m deep in the North Atlantic, including the Caribbean Sea, the Gulf of Mexico, Hudson Bay and the North Sea, but excluding estuaries. The total areas within these depths, from the equator to 70 degrees N, are 3.91 x 10(6) km(2) and 5.66 x 10(6) km(2), respectively. We also report the respective areas by selected geographic regions. C1 RUTGERS STATE UNIV,INST MARINE & COASTAL SCI,NOAA,CMER PROGRAM,PISCATAWAY,NJ 08855. RP Pilson, MEQ (reprint author), UNIV RHODE ISL,GRAD SCH OCEANOG,KINGSTON,RI 02881, USA. NR 5 TC 3 Z9 3 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0168-2563 J9 BIOGEOCHEMISTRY JI Biogeochemistry PD OCT PY 1996 VL 35 IS 1 BP 227 EP 233 DI 10.1007/BF02179828 PG 7 WC Environmental Sciences; Geosciences, Multidisciplinary SC Environmental Sciences & Ecology; Geology GA VU200 UT WOS:A1996VU20000007 ER PT J AU Seitzinger, SP Giblin, AE AF Seitzinger, SP Giblin, AE TI Estimating denitrification in North Atlantic continental shelf sediments SO BIOGEOCHEMISTRY LA English DT Article; Proceedings Paper CT Workshop on Nitrogen Cycling in the North Atlantic Ocean and Its Watersheds CY MAY, 1994 CL BLOCK ISLAND, RI SP Sci Comm Problems Environm, Int Council Sci Unions DE benthic mineralization; continental shelf; denitrification; global N cycle; nitrogen; North Atlantic; nutrients; onwelling; phytoplankton; sediments ID SPRING PHYTOPLANKTON BLOOM; BENTHIC NUTRIENT REGENERATION; GULF-STREAM INTRUSIONS; ORGANIC-MATTER; NITROUS-OXIDE; OXYGEN-CONSUMPTION; NITROSOMONAS-EUROPAEA; SEA SEDIMENTS; GEORGIA BIGHT; CARBON AB A model of coupled nitrification/denitrification was developed for continental shelf sediments to estimate the spatial distribution of denitrification throughout shelf regions in the North Atlantic basin. Using data from a wide range of continental shelf regions, we found a linear relationship between denitrification and sediment oxygen uptake. This relationship was applied to specific continental shelf regions by combining it with a second regression relating sediment oxygen uptake to primary production in the overlying water. The combined equation was: denitrification (mmol N m(-2) d(-1)) = 0.019* phytoplankton production (mmol C m(-2) d(-1)). This relationship suggests that approximately 13% of the N incorporated into phytoplankton in shelf waters is eventually denitrified in the sediments via coupled nitrification/denitrification, assuming a C:N ratio of 6.625:1 for phytoplankton. The model calculated denitrification rates compare favorably with rates reported for several shelf regions in the North Atlantic. The model-predicted average denitrification rate for continental shelf sediments in the North Atlantic Basin is 0.69 mmol N m(-2) d(-1). Denitrification rates (per unit area) predicted by the model are highest for the continental shelf region in the western North Atlantic between Cape Hatteras and South Florida and lowest for Hudson Bay, the Baffin Island region, and Greenland. Within latitudinal belts, average denitrification rates were lowest in the high latitudes, intermediate in the tropics and highest in the mid-latitudes. Although denitrification rates per unit area are lowest in the high latitudes, the total N removal by denitrification (53 x 10(10) mol N y(-1)) is similar to that in the mid-latitudes (60 x 10(10) mol N y(-1)) due to the large area of continental shelf in the high latitudes. The Gulf of St. Lawrence/Grand Banks area and the North Sea are responsible for seventy-five percent of the denitrification in the high latitude region. N removal by denitrification in the western North Atlantic (96 x 10(10) mol N y(-1)) is two times greater than in the eastern North Atlantic (47 x 10(10) mol N y(-1)). This is primarily due to differences in the area of continental shelf in the two regions, as the average denitrification rate per unit area is similar in the western and eastern North Atlantic. We calculate that a total of 143 x 10(10) mol N y(-1) is removed via coupled nitrification/ denitrification on the North Atlantic continental shelf. This estimate is expected to underestimate total sediment denitrification because it does not include direct denitrification of nitrate from the overlying water. The rate of coupled nitrification/denitrification calculated is greater than the nitrogen inputs from atmospheric deposition and river sources combined, and suggests that onwelling of nutrient rich slope water is a major source of N for denitrification in shelf regions. For the two regions where N inputs to a shelf region from onwelling have been measured, onwelling appears to be able to balance the denitrification loss. C1 CTR ECOSYST,BIOL MARINE LAB,WOODS HOLE,MA 02543. RP Seitzinger, SP (reprint author), RUTGERS STATE UNIV,NOAA,CMER PROGRAM,INST MARINE & COASTAL SCI,NEW BRUNSWICK,NJ 08903, USA. NR 87 TC 189 Z9 195 U1 5 U2 56 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0168-2563 J9 BIOGEOCHEMISTRY JI Biogeochemistry PD OCT PY 1996 VL 35 IS 1 BP 235 EP 260 DI 10.1007/BF02179829 PG 26 WC Environmental Sciences; Geosciences, Multidisciplinary SC Environmental Sciences & Ecology; Geology GA VU200 UT WOS:A1996VU20000008 ER PT J AU Quinn, PK Barrett, KJ Dentener, FJ Lipschultz, F Six, KD AF Quinn, PK Barrett, KJ Dentener, FJ Lipschultz, F Six, KD TI Estimation of the air sea exchange of ammonia for the North Atlantic Basin SO BIOGEOCHEMISTRY LA English DT Article; Proceedings Paper CT Workshop on Nitrogen Cycling in the North Atlantic Ocean and Its Watersheds CY MAY, 1994 CL BLOCK ISLAND, RI SP Sci Comm Problems Environm, Int Council Sci Unions ID BLOOM EXPERIMENT; NITROGEN; WATERS; OCEAN; REGENERATION; EUROPE; CYCLES; SHELF; MODEL; FLUX AB As gas phase atmospheric ammonia reacts with acidic aerosol particles it affects the chemical, physical, and optical properties of the particles. A knowledge of the source strengths of NH3 is useful in determining the effect of NH3 on aerosol properties on a regional basis. Here, an attempt is made to determine the direction and magnitude of the air/sea flux of ammonia for the North Atlantic Basin from both measured and modeled seawater and atmospheric ammonia concentrations. Previously reported measured seawater concentrations range from less than 30 to 4600 nM with the highest concentrations reported for the Caribbean Sea, the North Sea, and the Belgium coast. Measured atmospheric ammonia concentrations range from 2 to 500 nmol m(-3) with the largest values occurring over the Sargasso Sea, the Caribbean Sea, and the North Sea. For comparison to the measurements, seawater ammonia concentrations were calculated by the Hamburg Model of the Ocean Carbon Cycle (HAMOCC3). HAMOCC3 open ocean values agree well with the limited number of reported measured concentrations. Calculated coastal values are lower than those measured, however, due to the coarse resolution of the model. Atmospheric ammonia concentrations were calculated by the Acid Deposition Model of the Meteorological Synthesizing Center (MSC-W) and by the global 3-dimensional model Moguntia. The two models predict similar annually averaged values but are about an order of magnitude lower than the measured concentrations. Over the North Sea and the NE Atlantic, the direction and magnitude of the air/sea ammonia flux calculated from MSC-W and Moguntia agree within the uncertainty of the calculations. Flux estimates derived from measured data are larger in both the positive and negative direction than the model derived values. The discrepancies between the measured and modeled concentrations and fluxes may be a result of sampling artifacts, inadequate chemistry and transport schemes in the models, or the difficulty in comparing point measurements to time-averaged model values. Sensitivity tests were performed which indicate that, over the range of values expected for the North Atlantic, the accuracy of the calculated flux depends strongly on seawater and atmospheric ammonia concentrations. Clearly, simultaneous and accurate measurements of seawater and atmospheric ammonia concentrations are needed to reduce the uncertainty of the Bur calculations, validate the model results, and characterize the role of oceanic ammonia emissions in aerosol processing and nitrogen cycling for the North Atlantic. C1 NORWEGIAN METEOROL INST,OSLO,NORWAY. AGR UNIV WAGENINGEN,WAGENINGEN,NETHERLANDS. BERMUDA BIOL STN RES,ST GEORGES,BERMUDA. MAX PLANCK INST METEOROL,HAMBURG,GERMANY. RP Quinn, PK (reprint author), NOAA,PACIFIC MARINE ENVIRONM LAB,7600 SAND POINT WAY NE,SEATTLE,WA 98115, USA. RI Quinn, Patricia/R-1493-2016; OI Quinn, Patricia/0000-0003-0337-4895; Lipschultz, Fred/0000-0003-1634-6754 NR 44 TC 25 Z9 25 U1 0 U2 4 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0168-2563 J9 BIOGEOCHEMISTRY JI Biogeochemistry PD OCT PY 1996 VL 35 IS 1 BP 275 EP 304 DI 10.1007/BF02179831 PG 30 WC Environmental Sciences; Geosciences, Multidisciplinary SC Environmental Sciences & Ecology; Geology GA VU200 UT WOS:A1996VU20000010 ER PT J AU Neff, WD AF Neff, WD TI Selected papers from the Seventh International Symposium on Acoustic Remote Sensing and Associated Techniques of the Atmosphere and Oceans, held in Boulder, Colorado, USA under the auspices of the International Society for Acoustic Remote Sensing (ISARS), October 1994 - Preface SO BOUNDARY-LAYER METEOROLOGY LA English DT Editorial Material RP Neff, WD (reprint author), NOAA,ENVIRONM RES LAB,ETL,BOULDER,CO 80303, USA. RI Neff, William/E-2725-2010 OI Neff, William/0000-0003-4047-7076 NR 0 TC 0 Z9 0 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0006-8314 J9 BOUND-LAY METEOROL JI Bound.-Layer Meteor. PD OCT PY 1996 VL 81 IS 1 BP R5 EP R6 PG 2 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA WB605 UT WOS:A1996WB60500001 ER PT J AU Fleming, RJ AF Fleming, RJ TI The use of commercial aircraft as platforms for environmental measurements SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID SYSTEM AB The use of commercial aircraft for obtaining weather and climate change related information is beginning to accelerate at a rapid pace. A brief history of the use of commercial aircraft for these purposes is provided along with a discussion of the factors that are responsible for the current growth. A major federal program to provide profiles of winds, temperatures, and water vapor is described, along with a description of the new formats and information that will be available to the scientific community. Further details on the water vapor measurements, those expected this year and potential future upgrades, are provided. The advanced technologies that are now available on the aircraft, new advances in in situ and remote sensing, and an entrepreneurial spirit of some package carriers will combine to provide new kinds of measurements via commercial aircraft. A brief review of these factors and a vision of future environmental measurements is provided. RP Fleming, RJ (reprint author), NOAA, ENVIRONM RES LABS,CLIN OBSERV,OGP,ERL, 3300 MITCHELL LANE, SUITE 175, BOULDER, CO 80301 USA. NR 27 TC 18 Z9 18 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD OCT PY 1996 VL 77 IS 10 BP 2229 EP 2242 DI 10.1175/1520-0477(1996)077<2229:TUOCAA>2.0.CO;2 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VP991 UT WOS:A1996VP99100002 ER PT J AU Nowlin, WD Smith, N Needler, G Taylor, PK Weller, R Schmitt, R Merlivat, L Vezina, A Alexiou, A McPhaden, M Wakatsuchi, M AF Nowlin, WD Smith, N Needler, G Taylor, PK Weller, R Schmitt, R Merlivat, L Vezina, A Alexiou, A McPhaden, M Wakatsuchi, M TI An ocean observing system for climate SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID SEA-LEVEL AB Designs and implementation are proceeding for a Global Ocean Observing System (GOOS) and a Global Climate Observing System (GCOS). The initial design for the ocean component of the GCOS, which is also the climate module of the GOOS, was completed in 1995 by the Ocean Observing System Development Panel (OOSDP). This design for an ocean observing system for climate aims to provide ocean observations leading to gridded products, analyses, forecasts, indexes, assessments, and other items needed to detect, monitor, understand, and predict climate variations and change. A summary of the OOSDP report is presented here, beginning with the rationale for such a system and the series of specific goals and subgoals used to focus the design. The instruments, platforms, transmission systems, or processing required to observe the climate variables or quantifiable aspects of the climate system to meet these subgoals are identified. These observing system elements are divided into three categories: 1) elements of existing operational systems, 2) those that should be added now to complete the initial observing system, or 3) elements perhaps not now readily attainable but that should be added to the system at the earliest feasible time. Future research and development likely needed for further development of the system are also identified in the report. The elements needed for each subgoal are ranked as to feasibility (i.e., routine, systematic, timely, and cost-effective characteristics) versus their impact on attaining the subgoal. Priorities among the various subgoals are presented based on the panel's perception of where the immediate and important issues lie. This then provides the basis for an incremental approach to implementation, leading to a coherent conceptual design. C1 HOKKAIDO UNIV,INST LOW TEMP SCI,SAPPORO,HOKKAIDO,JAPAN. NOAA,PMEL,SEATTLE,WA. UNESCO,INTERGOVT OCEANOG COMMISS,PARIS,FRANCE. INST MAURICE LAMONTAGNE,QUEBEC CITY,PQ,CANADA. UNIV PARIS 06,LODYC,PARIS,FRANCE. WOODS HOLE OCEANOG INST,WOODS HOLE,MA 02543. SOUTHAMPTON OCEANOG CTR,SOUTHAMPTON,HANTS,ENGLAND. BEDFORD INST OCEANOG,BEDFORD,NS,CANADA. BUR METEOROL,RES CTR,MELBOURNE,VIC,AUSTRALIA. RP Nowlin, WD (reprint author), TEXAS A&M UNIV,DEPT OCEANOG,305 ARGUELLO DR,COLLEGE STN,TX 77840, USA. RI McPhaden, Michael/D-9799-2016 NR 26 TC 11 Z9 11 U1 1 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD OCT PY 1996 VL 77 IS 10 BP 2243 EP 2273 DI 10.1175/1520-0477(1996)077<2243:AOOSFC>2.0.CO;2 PG 31 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VP991 UT WOS:A1996VP99100003 ER PT J AU Johnson, VC Spayd, LE AF Johnson, VC Spayd, LE TI The COMET(R) outreach program: Cooperative research to improve operational forecasts SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article AB For the past five years, the Outreach Program, under the Cooperative Program for Operational Meteorology, Education and Training, has been fostering partnerships in applied forecasting research conducted by university faculty and operational forecasters. Over 100 research projects have received financial support. In addition, the Outreach Program has sponsored regional workshops and symposiums to provide forums for discussing Outreach Program results, as well as broader issues related to the new data becoming available through the modernization of the nation's weather services. The program has also recently created a fellowship program for outstanding graduate and postdoctoral students. These activities are not only improving forecasts, they are also providing benefits in meteorology education and a model for broader collaborations that advance the understanding of mesoscale meteorology. C1 NATL WEATHER SERV,METEOROL OFF,SILVER SPRING,MD. RP Johnson, VC (reprint author), UNIV CORP ATMOSPHER RES,COMET OUTREACH PROGRAM,POB 3000,BOULDER,CO 80307, USA. NR 7 TC 4 Z9 4 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD OCT PY 1996 VL 77 IS 10 BP 2317 EP 2332 DI 10.1175/1520-0477(1996)077<2317:EA>2.0.CO;2 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VP991 UT WOS:A1996VP99100008 ER PT J AU Brodeur, RD Frost, BW Hare, SR Francis, RC Ingraham, WJ AF Brodeur, RD Frost, BW Hare, SR Francis, RC Ingraham, WJ TI Interannual variations in zooplankton biomass in the Gulf of Alaska, and covariation with California current zooplankton biomass SO CALIFORNIA COOPERATIVE OCEANIC FISHERIES INVESTIGATIONS REPORTS LA English DT Article; Proceedings Paper CT CalCOFI Conference on Interdecadal Changes in the Ecology of the California Current: Evidence and Possible Mechanisms CY OCT 31-NOV 01, 1995 CL LAKE ARROWHEAD CONFERENCE CTR, CA SP CalCOFI Program HO LAKE ARROWHEAD CONFERENCE CTR ID NORTHEAST PACIFIC-OCEAN; CLIMATE CHANGE; VARIABILITY; ATLANTIC; TRENDS; COAST; SIZE AB Large-scale atmospheric and oceanographic conditions affect the productivity of oceanic ecosystems both locally and at some distance from the forcing mechanism. Recent studies have suggested that both the Subarctic Domain of the North Pacific Ocean and the California Current have undergone dramatic changes in zooplankton biomass that appear to be inversely related to each other. Using time series and correlation analyses, we characterized the historical nature of zooplankton biomass at Ocean Station P (50 degrees, 145 degrees W) and from offshore stations in the CalCOFI region. We found a statistically significant but weak negative relationship between the domains. We investigated whether such a relationship arises from different forcing mechanisms or as an opposite response to the same mechanism. We found that the seasonal peak of both data sets occurred in the summer but that the CalCOFI data lagged the Ocean Station P data. A surface-drift simulation model showed that winter trajectories started at Ocean Station P and along 145 degrees W drifted more into the California Current before the 1976-77 regime shift. and more into the Alaska Current after the 1976-77 shift. We examined physical and biological conditions which may lead to this inverse relationship between the two ecosystems, and we discuss the implications of these results for higher trophic levels. RP Brodeur, RD (reprint author), NOAA,ALASKA FISHERIES SCI CTR,7600 SAND POINT WAY NE,SEATTLE,WA 98115, USA. NR 76 TC 113 Z9 115 U1 0 U2 9 PU SCRIPPS INST OCEANOGRAPHY PI LA JOLLA PA A-003, LA JOLLA, CA 92093 SN 0575-3317 J9 CAL COOP OCEAN FISH JI Calif. Coop. Ocean. Fish. Invest. Rep. PD OCT PY 1996 VL 37 BP 80 EP 99 PG 20 WC Fisheries SC Fisheries GA VY004 UT WOS:A1996VY00400008 ER PT J AU MacCall, AD AF MacCall, AD TI Patterns of low-frequency variability in fish populations of the California current SO CALIFORNIA COOPERATIVE OCEANIC FISHERIES INVESTIGATIONS REPORTS LA English DT Article; Proceedings Paper CT CalCOFI Conference on Interdecadal Changes in the Ecology of the California Current: Evidence and Possible Mechanisms CY OCT 31-NOV 01, 1995 CL LAKE ARROWHEAD CONFERENCE CTR, CA SP CalCOFI Program HO LAKE ARROWHEAD CONFERENCE CTR ID SARDINE SARDINOPS-SAGAX; PACIFIC SARDINE; SPECIES REPLACEMENT; PELAGIC FISHES; ABUNDANCE; MODELS AB Long-term data sets include sedimentary fish-scale paleochronologies, faunal surveys from the 1800s, and the records of game fish catches maintained by the Tuna Club at Avalon since 1898. These data suggest a mode of low-frequency biological variability over a cycle of 50 to 70 years that is associated with alternation of warm and cold physical regimes. The very warm conditions in the northeastern Pacific Ocean since 1976 seem similar to conditions experienced from about 1850 to 1870 Coastal pelagic fish abundances since 1930 indicate an orderly sequence of four or five dominant species through these cycles that is very similar to the order and timing of fluctuations in catches of similar pelagic fishes in Japanese waters. The consistency and predictability of this rotation and the biological relationship to low-frequency fluctuations in physical conditions are important areas for further research. These patterns of low-frequency variability result in boom-and-bust fisheries, and pose serious problems for ''sustainable development.'' RP MacCall, AD (reprint author), NATL MARINE FISHERIES SERV,SW FISHERIES SCI CTR,3150 PARADISE DR,TIBURON,CA 94920, USA. NR 45 TC 80 Z9 81 U1 0 U2 3 PU SCRIPPS INST OCEANOGRAPHY PI LA JOLLA PA A-003, LA JOLLA, CA 92093 SN 0575-3317 J9 CAL COOP OCEAN FISH JI Calif. Coop. Ocean. Fish. Invest. Rep. PD OCT PY 1996 VL 37 BP 100 EP 110 PG 11 WC Fisheries SC Fisheries GA VY004 UT WOS:A1996VY00400009 ER PT J AU Dotson, RC Griffith, DA AF Dotson, RC Griffith, DA TI A high-speed midwater rope trawl for collecting coastal pelagic fishes SO CALIFORNIA COOPERATIVE OCEANIC FISHERIES INVESTIGATIONS REPORTS LA English DT Article; Proceedings Paper CT CalCOFI Conference on Interdecadal Changes in the Ecology of the California Current: Evidence and Possible Mechanisms CY OCT 31-NOV 01, 1995 CL LAKE ARROWHEAD CONFERENCE CTR, CA SP CalCOFI Program HO LAKE ARROWHEAD CONFERENCE CTR AB The development and testing of a new high-speed midwater rope trawl (HSMRT) was initiated in the fall of 1992 by the National Oceanic and Atmospheric Administration's (NOAA) National Marine Fisheries Service, Southwest Fisheries Science Center and the California Department of Fish and Game (CDFG). The HSMRT was designed to collect fishery-independent data for adult coastal pelagic fish species including Pacific sardine (Sardinops sagax), northern anchovy (Engraulis mordax), jack mackerel (Trachurus symmetricus), and Pacific mackerel (Scomber japonicus). Originally the trawl was constructed as a four-panel net with 53-meter head- and footropes with 6.50-meter meshes in the opening panels tapering down to 5-centimeter meshes in the rear and 10-centimeter meshes in the cod end. The net was modified after several cruises in 1992 and 1993 aboard NOAA's David Starr Jordan and CDFG's Mako. During fishing operations, targeted speeds of 4 to 4.5 knots were obtained by both vessels. For shallow tows, deployment took approximately 30 minutes with a fairly small crew (4-5 people). Fork lengths of fish captured ranged from 136 to 280 mm for Pacific sardine, 30 to 140 mm for northern anchovy, 50 to 320 mm for jack mackerel, and 60 to 450 mm for Pacific mackerel. Mature hydrated female sardine were taken during April-May, 1994, only by the Mako, which generally fished in deeper water than the David Starr Jordan. The HSMRT worked well on both the David Starr Jordan and the Mako, but because the Mako had less horsepower, it was unable to maneuver while trawling or to tow the net shallower than 18 meters below the surface. RP Dotson, RC (reprint author), NATL MARINE FISHERIES SERV,SW FISHERIES SCI CTR,POB 271,LA JOLLA,CA 92038, USA. NR 7 TC 10 Z9 10 U1 1 U2 2 PU SCRIPPS INST OCEANOGRAPHY PI LA JOLLA PA A-003, LA JOLLA, CA 92093 SN 0575-3317 J9 CAL COOP OCEAN FISH JI Calif. Coop. Ocean. Fish. Invest. Rep. PD OCT PY 1996 VL 37 BP 134 EP 139 PG 6 WC Fisheries SC Fisheries GA VY004 UT WOS:A1996VY00400012 ER PT J AU Macewicz, BJ CastroGonzalez, JJ CoteroAltamirano, CE Hunter, JR AF Macewicz, BJ CastroGonzalez, JJ CoteroAltamirano, CE Hunter, JR TI Adult reproductive parameters of Pacific sardine (Sardinops sagax) during 1994 SO CALIFORNIA COOPERATIVE OCEANIC FISHERIES INVESTIGATIONS REPORTS LA English DT Article; Proceedings Paper CT CalCOFI Conference on Interdecadal Changes in the Ecology of the California Current: Evidence and Possible Mechanisms CY OCT 31-NOV 01, 1995 CL LAKE ARROWHEAD CONFERENCE CTR, CA SP CalCOFI Program HO LAKE ARROWHEAD CONFERENCE CTR ID JAPANESE SARDINE; SOUTHWESTERN JAPAN; SPAWNING FREQUENCY; BATCH FECUNDITY; MELANOSTICTUS; CALIFORNIA; MACKEREL; ANCHOVY AB The average female Pacific sardine, Sardinops sagax, spawned about once every 15 days along the Pacific coast off California and Baja California during April-May 1994. The relation between batch fecundity and female weight without the ovary (W-of) was best estimated by the equation F-b = -10,585 + 439.53W(of). Fifty percent of the females reached sexual maturity by 158.6 mm standard length (95% CI 155 mm-162 mm). Data from surveys off California during 1986-1988 combined with the 1994 data indicated that peak daily spawning occurs between 19:00 and 22:59. The spawning cycle of sardine females with active ovaries averaged about one spawning every 7 days during 1986-94 off California. Our interpretation of the literature on sardine spawning indicates that they may spawn at similar rates in Chile, Japan, Australia, and South Africa. Finally, off California differences existed between months in the fraction of females that had active ovaries. These differences may indicate movements of groups of Pacific sardine away from and into the survey area. RP Macewicz, BJ (reprint author), NATL MARINE FISHERIES SERV,NOAA,SW FISHERIES SCI CTR,POB 271,LA JOLLA,CA 92038, USA. NR 40 TC 32 Z9 35 U1 1 U2 2 PU SCRIPPS INST OCEANOGRAPHY PI LA JOLLA PA A-003, LA JOLLA, CA 92093 SN 0575-3317 J9 CAL COOP OCEAN FISH JI Calif. Coop. Ocean. Fish. Invest. Rep. PD OCT PY 1996 VL 37 BP 140 EP 151 PG 12 WC Fisheries SC Fisheries GA VY004 UT WOS:A1996VY00400013 ER PT J AU Butler, JL Granados, ML Barnes, JT Yaremko, M Macewicz, BJ AF Butler, JL Granados, ML Barnes, JT Yaremko, M Macewicz, BJ TI Age composition, growth, and maturation of the Pacific sardine (Sardinops sagax) during 1994 SO CALIFORNIA COOPERATIVE OCEANIC FISHERIES INVESTIGATIONS REPORTS LA English DT Article; Proceedings Paper CT CalCOFI Conference on Interdecadal Changes in the Ecology of the California Current: Evidence and Possible Mechanisms CY OCT 31-NOV 01, 1995 CL LAKE ARROWHEAD CONFERENCE CTR, CA SP CalCOFI Program HO LAKE ARROWHEAD CONFERENCE CTR ID OTOLITH WEIGHT; NORTHERN ANCHOVY; ENGRAULIS-MORDAX; NEOPILCHARDUS; PILCHARD AB In conjunction with a study to estimate biomass based on daily egg production, Pacific sardine (Sardinops sagax) were independently aged by four or five readers using annuli in whole otoliths. Agreement among all five readers was only 31%, and an index of precision for estimated ages was 0.24. Ages ranged from one to seven years. The age composition of Pacific sardine in 1994 indicates a growing population or high adult mortality rates. Most of the biomass was in the youngest year classes. Very few fish were older than 4 years. Samples were taken from Baja California (26 degrees 40'N) to Monterey, California (36 degrees 40'N) during April and May 1994. Latitudinal dines in age of first maturity and size at age were found. Despite problems in age determination, it is clear that some sardines mature before their first birthday Sardine in the south mature at a younger age than in the north. Most sardine in the current population mature at age one, rather than at age two as reported for the population prior to the collapse of the fishery. RP Butler, JL (reprint author), NATL MARINE FISHERIES SERV,SW FISHERIES SCI CTR,POB 271,LA JOLLA,CA 92038, USA. NR 37 TC 25 Z9 27 U1 1 U2 3 PU SCRIPPS INST OCEANOGRAPHY PI LA JOLLA PA A-003, LA JOLLA, CA 92093 SN 0575-3317 J9 CAL COOP OCEAN FISH JI Calif. Coop. Ocean. Fish. Invest. Rep. PD OCT PY 1996 VL 37 BP 152 EP 159 PG 8 WC Fisheries SC Fisheries GA VY004 UT WOS:A1996VY00400014 ER PT J AU Lo, NCH Ruiz, YAG Cervantes, MJ Moser, HG Lynn, RJ AF Lo, NCH Ruiz, YAG Cervantes, MJ Moser, HG Lynn, RJ TI Egg production and spawning biomass of Pacific sardine (Sardinops sagax) in 1994, determined by the daily egg production method SO CALIFORNIA COOPERATIVE OCEANIC FISHERIES INVESTIGATIONS REPORTS LA English DT Article; Proceedings Paper CT CalCOFI Conference on Interdecadal Changes in the Ecology of the California Current: Evidence and Possible Mechanisms CY OCT 31-NOV 01, 1995 CL LAKE ARROWHEAD CONFERENCE CTR, CA SP CalCOFI Program HO LAKE ARROWHEAD CONFERENCE CTR ID CALIFORNIA; ANCHOVY; GROWTH AB The daily egg production method (DEPM) was used to compute spawning biomass of Pacific sardine ill a 380.175 km(2) (111,081 n.mi.(2)) area from San Ignacio Lagoon, south of Punta Abreojos, Baja California Sur, to San Francisco, California, during April-May 1994. The estimated spawning biomass was 111,493 MT (CV = 0.32) with an approximated 95% confidence interval (40,000 MT, 182,800 MT). Daily egg production in the survey area was 0.169 eggs/0.05 m(2)/day (CV 0.22), and daily specific fecundity was 11.53 eggs/gm/day. Estimates for adult parameters were: sex ratio, 0.53 (CV = 0.067); average female weight, 82.49 gm (CV = 0.071); spawning frequency, 0.073 (CV = 0.23); and average batch fecundity, 24,382.52 (CV = 0.11). We estimated peak spawning time for Pacific sardine (9:00 p.m.) and coefficients in a temperature-dependent egg-development model. Egg density in 1994 was similar to that in 1986, indicating that the increase in spawning biomass during 1986-94 was due to expansion of spawning area rather than to increased density of spawners. Most of the eggs collected were found in waters off California and were distributed along temperature gradients formed by upwelling. Surface temperatures of about 13.8 degrees seemed to limit the inshore distribution of eggs. Food supply, rather than temperature, may have limited the offshore distribution. RP Lo, NCH (reprint author), NATL MARINE FISHERIES SERV,SW FISHERIES SCI CTR,POB 271,LA JOLLA,CA 92038, USA. NR 43 TC 50 Z9 51 U1 1 U2 8 PU SCRIPPS INST OCEANOGRAPHY PI LA JOLLA PA A-003, LA JOLLA, CA 92093 SN 0575-3317 J9 CAL COOP OCEAN FISH JI Calif. Coop. Ocean. Fish. Invest. Rep. PD OCT PY 1996 VL 37 BP 160 EP 174 PG 15 WC Fisheries SC Fisheries GA VY004 UT WOS:A1996VY00400015 ER PT J AU Bentley, PJ Emmett, RL Lo, NCH Moser, HG AF Bentley, PJ Emmett, RL Lo, NCH Moser, HG TI Egg production of Pacific sardine (Sardinops sagax) off Oregon in 1994 SO CALIFORNIA COOPERATIVE OCEANIC FISHERIES INVESTIGATIONS REPORTS LA English DT Article; Proceedings Paper CT CalCOFI Conference on Interdecadal Changes in the Ecology of the California Current: Evidence and Possible Mechanisms CY OCT 31-NOV 01, 1995 CL LAKE ARROWHEAD CONFERENCE CTR, CA SP CalCOFI Program HO LAKE ARROWHEAD CONFERENCE CTR AB Since the late 1970s, the Pacific sardine (Sardinops sagax) population off the west coast of the United States has been increasing. In 1994, an ichthyoplankton survey to assess anchovy biomass was conducted off the Oregon coast from the Columbia River to the Coquille River (just north of Cape Blanco) and out to 190 km offshore. Samples collected during the survey contained numerous Pacific sardine eggs and larvae, which were used to estimate daily egg production (0.42 eggs/0.05 m(2)/day) and egg mortality (0.13/day). The spawning biomass of Pacific sardine was calculated to be about 50,000 MT. There appears to be an association between geographic distribution of sardine eggs and the 14 degrees C isotherm derived from the 1-m to 10-m depth zone. We hypothesize that the isotherm of 14 degrees C forms a distinct boundary for spawning sardine off Oregon and may prove useful for determining boundaries for future spawning surveys. RP Bentley, PJ (reprint author), NOAA,NATL MARINE FISHERIES SERV,NW FISHERIES SCI CTR,2725 MONTLAKE BLVD E,SEATTLE,WA 98112, USA. NR 33 TC 13 Z9 13 U1 0 U2 0 PU SCRIPPS INST OCEANOGRAPHY PI LA JOLLA PA A-003, LA JOLLA, CA 92093 SN 0575-3317 J9 CAL COOP OCEAN FISH JI Calif. Coop. Ocean. Fish. Invest. Rep. PD OCT PY 1996 VL 37 BP 193 EP 200 PG 8 WC Fisheries SC Fisheries GA VY004 UT WOS:A1996VY00400018 ER PT J AU Brown, ED Norcross, BL Short, JW AF Brown, ED Norcross, BL Short, JW TI An introduction to studies on the effects of the Exxon Valdez oil spill on early life history stages of Pacific herring, Clupea pallasi, in Prince William Sound, Alaska SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID SEA-SURFACE MICROLAYER; TOXICITY; HARENGUS C1 NATL MARINE FISHERIES SERV,ALASKA FISHERIES SCI CTR,AUKE BAY LAB,AUKE BAY,AK 99821. RP Brown, ED (reprint author), UNIV ALASKA,INST MARINE SCI,SCH FISHERIES & OCEAN SCI,FAIRBANKS,AK 99775, USA. NR 38 TC 22 Z9 22 U1 1 U2 9 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA ON K1A 0R6, CANADA SN 0706-652X J9 CAN J FISH AQUAT SCI JI Can. J. Fish. Aquat. Sci. PD OCT PY 1996 VL 53 IS 10 BP 2337 EP 2342 DI 10.1139/cjfas-53-10-2337 PG 6 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA WE260 UT WOS:A1996WE26000019 ER PT J AU Schantz, MM Porter, BJ Wise, SA Segstro, M Muir, DCG Mossner, S Ballschmiter, K Becker, PR AF Schantz, MM Porter, BJ Wise, SA Segstro, M Muir, DCG Mossner, S Ballschmiter, K Becker, PR TI Interlaboratory comparison study for PCB congeners and chlorinated pesticides in beluga whale blubber SO CHEMOSPHERE LA English DT Article ID POLYCHLORINATED-BIPHENYLS; SYSTEMATIC-ERRORS; WIDE-SPREAD; GAS-CHROMATOGRAPHY; CONTAMINANTS; SOILS; CHLOROBIPHENYLS; OIL AB Three laboratories participated in an interlaboratory comparison exercise for the determination of polychlorinated biphenyl (PCB) congeners and chlorinated pesticides in Standard Reference Material (SRM) 1588 (Organics in Cod Liver Oil) a whale blubber control material, and six beluga whale (Delphinapterus leucas) blubber samples. The results are generally in good agreement. The minor disagreement of some of the results may be attributed to differences in detector calibrations, differences in chromatographic separation selectivity for specific compounds, or both The SRM and control material help to validate the analytical procedures and to verify that these procedures remain in control. Published by Elsevier Science Ltd C1 FISHERIES & OCEANS CANADA, INST FRESHWATER, WINNIPEG, MB R3T 2N6, CANADA. UNIV ULM, DEPT ANALYT & ENVIRONM CHEM, D-89081 ULM, GERMANY. NATL INST STAND & TECHNOL, DIV ANALYT CHEM, CHARLESTON, SC 29412 USA. NATL INST STAND & TECHNOL, DIV ANALYT CHEM, GAITHERSBURG, MD 20899 USA. OI Muir, Derek/0000-0001-6631-9776 NR 32 TC 13 Z9 13 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0045-6535 EI 1879-1298 J9 CHEMOSPHERE JI Chemosphere PD OCT PY 1996 VL 33 IS 7 BP 1369 EP 1390 DI 10.1016/0045-6535(96)00272-X PG 22 WC Environmental Sciences SC Environmental Sciences & Ecology GA VF703 UT WOS:A1996VF70300014 PM 8799997 ER PT J AU Allen, MR Robertson, AW AF Allen, MR Robertson, AW TI Distinguishing modulated oscillations from coloured noise in multivariate datasets SO CLIMATE DYNAMICS LA English DT Article ID SINGULAR-SPECTRUM ANALYSIS; TIME-SERIES; CLIMATE; DYNAMICS; RECONSTRUCTION; VARIABILITY; PREDICTION AB Extended empirical orthogonal functions (EEOFs), alternatively known as multi-channel singular systems (or singular spectrum) analysis (MSSA), provide a natural method of extracting oscillatory modes of variability from multivariate data. The eigenfunctions of some simple non-oscillatory noise processes are, however, also solutions to the wave equation, so the occurrence of stable, wave-like patterns in EEOF/MSSA is not sufficient grounds for concluding that data exhibits oscillations. We present a generalisation of the ''Monte Carlo SSA'' algorithm which allows an objective test for the presence of oscillations at low signal-to-noise ratios in multivariate data;The test is similar to those used in standard regression, examining directions in state-space to determine whether they contain more variance than would be expected if the noise null-hypothesis were valid. We demonstrate the application of the test to the analysis of interannual variability in tropical Pacific sea-surface temperatures. C1 UNIV CALIF LOS ANGELES,DEPT ATMOSPHER SCI,LOS ANGELES,CA 90095. UNIV CALIF LOS ANGELES,INST GEOPHYS & PLANETARY PHYS,LOS ANGELES,CA 90095. RUTHERFORD APPLETON LAB,DEPT SPACE SCI,DIDCOT OX11 0QX,OXON,ENGLAND. UNIV OXFORD,DEPT PHYS,OXFORD,ENGLAND. RP Allen, MR (reprint author), MIT,CTR METEOROL & PHYS OCEANOG,NOAA,POSTDOCTORAL PROGRAM CLIMATE & GLOBAL CHANGE,CAMBRIDGE,MA 02139, USA. RI Allen, Myles/A-5172-2012; Robertson, Andrew/H-7138-2015 NR 33 TC 68 Z9 69 U1 0 U2 12 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0930-7575 J9 CLIM DYNAM JI Clim. Dyn. PD OCT PY 1996 VL 12 IS 11 BP 775 EP 784 DI 10.1007/s003820050142 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VN773 UT WOS:A1996VN77300004 ER PT J AU Linteris, GT AF Linteris, GT TI Numerically predicted structure and burning velocity of premixed CO-Ar-O-2-H-2 flames inhibited by CF3H SO COMBUSTION AND FLAME LA English DT Article ID ATOM-RADICAL KINETICS; F-SUBSTITUTED METHANES; HYDROGEN AB This paper presents the first detailed numerical calculations of the structure of carbon monoxide-hydrogen-oxygen-argon flames inhibited by CF3H. Numerical solution of the equations of mass, species, and energy conservation are performed using a chemical kinetic mechanism recently developed at the National Institute of Standards and Technology. The calculated burning velocities are compared with a set of previously published experimental measurements performed by another laboratory which encompass a range of equivalence ratios and argon, hydrogen, and inhibitor mole fractions with corresponding burning velocities of 21 to 199 cm/s. The effects of the inhibitor on the species profiles for the major products, radicals, and fluorinated compounds are determined, and the major reaction pathways for consumption of the inhibitor are discussed. The previously published experimental burning velocities are in good agreement with the results of the present calculations for most of the conditions tested. For those conditions (high fluorine-to-hydrogen ratio in the reactants) where the disagreement is largest, the rate expressions which most influence the burning velocity have been identified. The modeling results indicate that in CO flames (in contrast to hydrocarbon flames) oxygen atom reaction with the inhibitor and inhibitor fragments is a major decomposition pathway, especially when there is a high fluorine-to-hydrogen ratio in the reactants. RP Linteris, GT (reprint author), NIST,FIRE SCI DIV,BLDG & FIRE RES LAB,RM B356,BLDG 224,GAITHERSBURG,MD 20899, USA. NR 43 TC 8 Z9 12 U1 1 U2 1 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 0010-2180 J9 COMBUST FLAME JI Combust. Flame PD OCT PY 1996 VL 107 IS 1-2 BP 72 EP 84 DI 10.1016/0010-2180(96)00009-0 PG 13 WC Thermodynamics; Energy & Fuels; Engineering, Multidisciplinary; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA VK402 UT WOS:A1996VK40200007 ER PT J AU Gupta, SM McLean, CR AF Gupta, SM McLean, CR TI Disassembly of products SO COMPUTERS & INDUSTRIAL ENGINEERING LA English DT Article; Proceedings Paper CT 19th International Conference on Computers and Industrial Engineering CY MAR 04-06, 1996 CL MIAMI, FL AB With incoming recycling regulations, resource conservation needs and an increased awareness of the state of the environment by both the consumer and the producer, a fundamental reappraisal of the traditional manufacturing paradigm has been emerging. The manufacturers are under tremendous pressure to dispose of products in an environmentally responsible manner. To this end many companies are establishing disassembly plants and developing product designs which specifically facilitate disassembly. Once disassembled, the items can be reused, recycled or discarded. This paper provides an overview of the research in the area of disassembly of products. C1 NATL INST STAND & TECHNOL, MFG SYST INTEGRAT DIV, GAITHERSBURG, MD 20899 USA. RP Gupta, SM (reprint author), NORTHEASTERN UNIV, DEPT MECH MAT & MFG ENGN, BOSTON, MA 02115 USA. NR 11 TC 51 Z9 53 U1 2 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0360-8352 J9 COMPUT IND ENG JI Comput. Ind. Eng. PD OCT PY 1996 VL 31 IS 1-2 BP 225 EP 228 DI 10.1016/0360-8352(96)00146-5 PG 4 WC Computer Science, Interdisciplinary Applications; Engineering, Industrial SC Computer Science; Engineering GA VL013 UT WOS:A1996VL01300057 ER PT J AU Grafton, RQ Squires, D Kirkley, JE AF Grafton, RQ Squires, D Kirkley, JE TI Private property rights and crises in world fisheries: Turning the tide? SO CONTEMPORARY ECONOMIC POLICY LA English DT Article ID RENT CAPTURE; MANAGEMENT; RESOURCE; UNCERTAINTY; QUOTA AB This addresses the crises in the world's fisheries involving dwindling stocks, overcapitalization, and jurisdiction disputes from a property rights perspective. In particular, it examines the causes of the problems fishers face and explores the potential of privatizing the right to catch fish as a means to address the crises. The analysis assesses experiences of private harvesting rights with reference to monitoring and enforcement, allocating rights, economic benefits, adjustments in the fishery, and resource rents. It also examines issues such as fluctuating fish stocks, straddling stocks and high seas fisheries, and the endemic poverty of many artisanal fisheries in the context of current fisheries practice. C1 US NATL MARINE FISHERIES SERV,LA JOLLA,CA. COLL WILLIAM & MARY,VIRGINIA INST MARINE SCI,WILLIAMSBURG,VA 23187. RP Grafton, RQ (reprint author), UNIV OTTAWA,DEPT ECON,OTTAWA,ON,CANADA. RI Grafton, R. Quentin/A-5277-2008 OI Grafton, R. Quentin/0000-0002-0048-9083 NR 49 TC 28 Z9 28 U1 0 U2 8 PU WESTERN ECONOMIC ASSOC INT PI HUNTINGTON BEACH PA 7400 CENTER AVE SUITE 109, HUNTINGTON BEACH, CA 92647-3039 SN 0735-0007 J9 CONTEMP ECON POLICY JI Contemp. Econ. Policy PD OCT PY 1996 VL 14 IS 4 BP 90 EP 99 PG 10 WC Economics; Public Administration SC Business & Economics; Public Administration GA VP785 UT WOS:A1996VP78500008 ER PT J AU Gilliland, GL Ladner, JE AF Gilliland, GL Ladner, JE TI Crystallization of biological macromolecules for X-ray diffraction studies SO CURRENT OPINION IN STRUCTURAL BIOLOGY LA English DT Article ID VAPOR-DIFFUSION CRYSTALLIZATION; TETRAGONAL LYSOZYME CRYSTALS; DYNAMIC LIGHT-SCATTERING; PROTEIN CRYSTALS; LIPID LAYERS; RELATIVE EFFECTIVENESS; POLYETHYLENE-GLYCOL; EPITAXIAL-GROWTH; FUSION PROTEINS; SOLUBILITY AB Advances in the crystallization of biological macromolecules have come not only from the application of biochemical, molecular biological and immunological principles and techniques, but also from continued efforts to understand the crystallization process. Developments in crystallization methodologies, protocols, and reagents are also facilitating crystallization efforts. C1 NIST,ROCKVILLE,MD 20850. RP Gilliland, GL (reprint author), UNIV MARYLAND,MARYLAND BIOTECHNOL INST,CTR ADV RES BIOTECHNOL,9600 GUDELSKY DR,ROCKVILLE,MD 20850, USA. NR 60 TC 10 Z9 12 U1 34 U2 102 PU CURRENT BIOLOGY LTD PI LONDON PA 34-42 CLEVELAND STREET, LONDON, ENGLAND W1P 6LB SN 0959-440X J9 CURR OPIN STRUC BIOL JI Curr. Opin. Struct. Biol. PD OCT PY 1996 VL 6 IS 5 BP 595 EP 603 DI 10.1016/S0959-440X(96)80024-8 PG 9 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA VP616 UT WOS:A1996VP61600003 PM 8913680 ER PT J AU Coleman, FC Koenig, CC Collins, LA AF Coleman, FC Koenig, CC Collins, LA TI Reproductive styles of shallow-water groupers (Pisces: Serranidae) in the eastern Gulf of Mexico and the consequences of fishing spawning aggregations SO ENVIRONMENTAL BIOLOGY OF FISHES LA English DT Article DE sex ratio; protogyny; sex change; spawning; selective fishing pressure ID CORAL-REEF FISH; EPINEPHELUS-GUTTATUS; SEX-CHANGE; SOCIAL-GROUPS; LIFE-HISTORY; RED HIND; SIZE; STRIATUS; GAG AB Seasonal and spatial aspects of spawning for three commercially important grouper species in the northeastern Gulf of Mexico are detailed. These species - all of which are protogynous hermaphrodites - spawn in deep water (> 25 m for red grouper, > 40 m for gag and scamp), making it difficult to observe spawning behaviors without ROV or submersible support. They respond to intense fishing pressure in ways that are directly related to their respective reproductive styles. Species that aggregate appear to be more susceptible to such pressures than those that do not, as evidenced by marked skewing of sex ratios in favor of females. Gag, Mycteroperca microlepis, have suffered a drop in the proportion of males from 17% to 1% in the last 20 years; scamp, Mycteroperca phenax, have dropped from 36% to 18%; and red grouper, Epinephelus morio, which do not aggregate, have shown little change in the sex ratio over the past 25-30 years. C1 NATL MARINE FISHERIES SERV,PANAMA CITY,FL 32408. RP Coleman, FC (reprint author), FLORIDA STATE UNIV,DEPT BIOL SCI,INST FISHERY RESOURCE ECOL,NMFS,FSU,B-157,TALLAHASSEE,FL 32306, USA. NR 37 TC 222 Z9 228 U1 4 U2 38 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0378-1909 J9 ENVIRON BIOL FISH JI Environ. Biol. Fishes PD OCT PY 1996 VL 47 IS 2 BP 129 EP 141 DI 10.1007/BF00005035 PG 13 WC Ecology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA VJ958 UT WOS:A1996VJ95800002 ER PT J AU McConnell, LL Kucklick, JR Bidleman, TF Ivanov, GP Chernyak, SM AF McConnell, LL Kucklick, JR Bidleman, TF Ivanov, GP Chernyak, SM TI Air-water gas exchange of organochlorine compounds in Lake Baikal, Russia SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID HENRY LAW CONSTANTS; POLYCYCLIC AROMATIC-HYDROCARBONS; CHROMATOGRAPHY MASS-SPECTROMETRY; ELECTRON-CAPTURE DETECTION; POLYCHLORINATED-BIPHENYLS; ATMOSPHERIC TRANSPORT; GREEN BAY; TOXAPHENE; HEXACHLOROCYCLOHEXANE; VOLATILIZATION AB Air and surface water samples were collected at Lake Baikal, Russia, during June 1991 to determine concentrations of organochlorine pesticides and polychlorinated biphenyl (PCB) congeners. These data were combined with Henry's law constants to estimate the gas flux rate across the air-water interface of each compound class. Air samples were collected at Lake Baikal and from nearby Irkutsk. Water samples were collected from three mid-lake stations and at the mouth of two major tributaries. Average air concentrations of chlorinated bornanes (14 pg m(-3)), chlordanes (4.9 pg m(-3)), and hexachlorobenzene (HCB) (194 pg m(-3)) were similar to global background or Arctic levels. However, air concentrations of hexachlorocyclohexanes (HCHs), DDTs, and PCBs were closer to those observed in the Great Lakes region. Significantly higher levels of these three compound classes in air over Irkutsk suggests that regional atmospheric transport and deposition may be an important source of these persistent compounds to Lake Baikal. Air-water gas exchange calculations resulted in net depositional flux values for alpha-HCH, gamma-HCH, DDTs, and chlorinated bornanes at 112, 23, 3.6, and 2.4 ng m(-2) d(-1), respectively. The total net flux of 22 PCB congeners, chlordanes, and HCB was from water to air (volatilization) at 47, 1.8, and 32 ng m(-2) d(-1), respectively. C1 NATL MARINE FISHERIES SERV,SE FISHERIES SCI CTR,CHARLESTON,SC 29422. UNIV S CAROLINA,DEPT CHEM & BIOCHEM,COLUMBIA,SC 29208. UNIV S CAROLINA,MARINE SCI PROGRAM,COLUMBIA,SC 29208. RUSSIAN ACAD SCI,INST LIMNOL,IRKUTSK 664003,RUSSIA. MOSCOW FISHERIES INST,MOSCOW,RUSSIA. RP McConnell, LL (reprint author), USDA ARS,ENVIRONM CHEM LAB,BELTSVILLE,MD 20705, USA. RI McConnell, Laura/H-1519-2011; Bidleman, Terry/F-6287-2011 OI Bidleman, Terry/0000-0001-7469-0532 NR 56 TC 69 Z9 74 U1 2 U2 15 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD OCT PY 1996 VL 30 IS 10 BP 2975 EP 2983 DI 10.1021/es9509487 PG 9 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA VL046 UT WOS:A1996VL04600033 ER PT J AU Lubkowski, J Palm, GJ Gilliland, GL Derst, C Rohm, KH Wlodawer, A AF Lubkowski, J Palm, GJ Gilliland, GL Derst, C Rohm, KH Wlodawer, A TI Crystal structure and amino acid sequence of Wolinella succinogenes L-asparaginase SO EUROPEAN JOURNAL OF BIOCHEMISTRY LA English DT Article DE L-asparaginase; cloning; sequence; crystal structure; Wolinella succinogenes ID ACUTE LYMPHOBLASTIC-LEUKEMIA; ESCHERICHIA-COLI; GLUTAMINASE-ASPARAGINASE; INTENSIVE ASPARAGINASE; VIBRIO-SUCCINOGENES; PURIFICATION; MUTAGENESIS; INDUCTION; THERAPY AB The amino acid sequence and tertiary structure of Wolinella succinogenes L-asparaginase were determined, and were compared with the structures of other type-II bacterial L-asparaginases. Each chain of this homotetrameric enzyme consists of 330 residues. The amino acid sequence is 40-50% identical to the sequences of related proteins from other bacterial sources, and all residues previously shown to be crucial for the catalytic action of these enzymes are identical. Differences between the amino acid sequence of W. succinogenes L-asparaginase and that of related enzymes are discussed in terms of the possible influence on the substrate specificity. The overall fold of the protein subunit is almost identical to that observed for other L-asparaginases. Two fragments in each subunit, a very highly flexible loop (approximate to 20 amino acids) that forms part of the active site, and the N-terminus (two amino acids), are not defined in the structure. The orientation of Thr14, a residue probably involved in the catalytic activity, indicates the absence of ligand in the active-site pocket. The rigid part of the active site, which includes the asparaginase triad Thr93-Lys166-Asp94, is structurally very highly conserved with equivalent regions found in other type-II bacterial L-asparaginases. C1 UNIV MARYLAND,MARYLAND BIOTECHNOL INST,CTR ADV RES BIOTECHNOL,ROCKVILLE,MD 20850. NIST,ROCKVILLE,MD 20850. UNIV MARBURG,INST PHYSIOL CHEM,D-3550 MARBURG,GERMANY. RP Lubkowski, J (reprint author), NCI,FREDERICK CANC RES & DEV CTR,ABL BASIC RES PROGRAM,MACROMOL STRUCT LAB,FREDERICK,MD 21702, USA. NR 39 TC 70 Z9 78 U1 0 U2 4 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0014-2956 J9 EUR J BIOCHEM JI Eur. J. Biochem. PD OCT PY 1996 VL 241 IS 1 BP 201 EP 207 DI 10.1111/j.1432-1033.1996.0201t.x PG 7 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA VL748 UT WOS:A1996VL74800028 PM 8898907 ER PT J AU Friedland, KD Haas, RE Sheehan, TF AF Friedland, KD Haas, RE Sheehan, TF TI Post-smolt growth, maturation, and survival of two stocks of Atlantic salmon SO FISHERY BULLETIN LA English DT Article ID ONCORHYNCHUS-KISUTCH; COHO SALMON; PHENOTYPIC PLASTICITY; BRITISH-COLUMBIA; MARINE SURVIVAL; SOCKEYE-SALMON; SALAR SMOLTS; OCEAN GROWTH; ARCTIC CHARR; SIZE AB Marine survival and sea-age at maturity of two hatchery-dependent stocks of Atlantic salmon were compared in respect to differences in post-smelt growth as evidenced by the circuli spacing patterns of their scales. The two stocks, the Penobscot and Connecticut, are located at the southern extent of the range of Atlantic salmon in North America. Return rates for 1SW (one seawinter) and 2SW salmon and the fraction of the smelt year class or cohort that matured as 1SW fish were found to be significantly higher for the Penobscot stock. Using image processing techniques, we extracted intercirculi distances from scales of 2,302 2SW fish. Circuli spacing data were expressed as growth indices for spring (when post-smelts first enter the ocean), summer (when growth appears maximal), and winter (when growth appears to be at a minimum). Circuli spacings of the Penobscot fish were wider during the summer season than were those for conspecifics from the Connecticut River of the same smelt year class. The results suggest that post-smelt growth may play a significant role in deciding age at maturity and survival patterns for Atlantic salmon stocks. RP Friedland, KD (reprint author), NOAA,NATL MARINE FISHERIES SERV,166 WATER ST,WOODS HOLE,MA 02543, USA. NR 57 TC 29 Z9 30 U1 3 U2 6 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD OCT PY 1996 VL 94 IS 4 BP 654 EP 663 PG 10 WC Fisheries SC Fisheries GA VM745 UT WOS:A1996VM74500005 ER PT J AU Kimura, DK Balsiger, JW Ito, DH AF Kimura, DK Balsiger, JW Ito, DH TI Kalman filtering the delay-difference equation: Practical approaches and simulations SO FISHERY BULLETIN LA English DT Article ID SURPLUS PRODUCTION MODELS; STOCK REDUCTION ANALYSIS; GENERAL-THEORY; CATCH; UNCERTAINTY AB Recently, J. J. Pella showed how the Kalman filter could be applied to production modeling to estimate the size and productivity of fish stocks from a time series of catches and relative abundance indices. We apply these methods to the Deriso-Schnute delay-difference equation. The Kalman filter approach incorporates process and measurement error naturally in the model description. When the production model is the delay-difference equation, the error structure is particularly attractive because process error can be interpreted as simply the variance of recruitment; and measurement error as the variance of the relative abundance estimates. We derived prior distributions of initial biomass in order to begin the Kalman filter calculations. Reanalysis of the data from the eastern tropical Pacific for yellowfin tuna, Thunnus albacares, shows that modeling results can differ greatly depending on whether error is interpreted to be process error or measurement error. Simulation results show that nonlinear least squares and Kalman filter estimates agree well if data contain only measurement error. In contrast, the Kalman filter was clearly superior if simulated data contained significant amounts of process error. The presence of process error positively biased biomass estimates from both the nonlinear least-squares and Kalman filter methods. The Kalman filter performed well with Schnute's form of the delay-difference equation, even though this model violates the assumption of independent process error vectors. The Kalman filter also performed well when the variance ratio r was assumed known and individual variances were estimated from the data. However, it appeared difficult to estimate r as a parameter in the maximum-likelihood estimation. RP Kimura, DK (reprint author), NOAA,NATL MARINE FISHERIES SERV,ALASKA FISH SCI CTR,7600 SAND POINT WAY NE,SEATTLE,WA 98115, USA. NR 29 TC 23 Z9 23 U1 0 U2 0 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD OCT PY 1996 VL 94 IS 4 BP 678 EP 691 PG 14 WC Fisheries SC Fisheries GA VM745 UT WOS:A1996VM74500008 ER PT J AU Ramon, D Bailey, K AF Ramon, D Bailey, K TI Spawning seasonality of albacore, Thunnus alalunga, in the South Pacific ocean SO FISHERY BULLETIN LA English DT Article ID TUNA; SCOMBRIDAE AB The spawning seasonality of albacore, Thunnus alalunga, in the South Pacific was studied by examining ovaries and testes collected from longline vessels operating in the waters off New Caledonia (21 degrees-23 degrees S, 164 degrees-166 degrees E) and Tonga (16 degrees-29 degrees S, 171 degrees-177 degrees W), January 1990 to February 1992. The monthly change in GSI values and mean oocyte diameters indicated that albacore are annual spawners, with most spawning limited to the austral summer months from November to February. Asymmetry in weight of, but not in the reproductive development of, the left and right gonad pairs was apparent in samples from the two collection sites; most right ovaries and testes were heavier and larger than those on the left side. C1 S PACIFIC COMMISS,TUNA & BILLFISH ASSESSMENT PROGRAMME,NOUMEA,NEW CALEDONIA. RP Ramon, D (reprint author), NOAA,NATL MARINE FISHERIES SERV,SW FISHERIES SCI CTR,LA JOLLA,CA 92038, USA. NR 25 TC 15 Z9 18 U1 0 U2 3 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD OCT PY 1996 VL 94 IS 4 BP 725 EP 733 PG 9 WC Fisheries SC Fisheries GA VM745 UT WOS:A1996VM74500011 ER PT J AU Schultz, DR Arnold, PI Capo, TR ParisLimouzy, CB Serafy, JE Richards, WJ AF Schultz, DR Arnold, PI Capo, TR ParisLimouzy, CB Serafy, JE Richards, WJ TI Immunologic methods for species identification of early life stages of lutjanid fishes from the western central Atlantic .1. Characterization of an interspecies protein SO FISHERY BULLETIN LA English DT Article ID LINKED-IMMUNOSORBENT-ASSAY; MONOCLONAL-ANTIBODIES; SUBFAMILY LUTJANINAE AB A 66 kDa glycoprotein selected from SDS-PAGE gel profiles of soluble extracts of Lutjanus griseus was purified by Fast Protein Liquid Chromatography technology. A polyclonal antiserum produced to the single-chained glycoprotein was tested with 14 other lutjanid extracts in Western blots and produced 3 different patterns: strong reactions with L. jocu and L. apodus; weak reactions with L. buccanella, L. synagris, L. analis, L. campechanus, Pristipomoides aquilonaris, Ocyurus chrysurus, and Apsilus dentatus; no reactions with L. vivanus, L. mahogoni, L. cyanopterus, Etelis oculata, and the hybrid L. synagris x O. chrysurus. The anti-66 kDa antiserum also reacted strongly with soluble extracts of oocytes and juveniles of L. griseus. Adsorption of the IgG fraction of the antiserum with glutaraldehyde-insolubilized L. apodus extract resulted in an antiserum that remained strongly reactive with L. griseus extract but that was weakly reactive with L. apodus extract and negative with L. jocu extract in Western blots. The N-terminal amino acid sequence analyses of the first 10 residues of the purified 66 kDa proteins of L. griseus and L. jocu were approximately the same, but only 3 of 10 residues were the same with the purified proteins of L. griseus and L. apodus. Extracts of L. apodus contained 3 additional proteins that were not detected in extracts of L. griseus as determined by SDS-PAGE. This evidence for both interspecies and species-specific protein determinants is currently being used to produce species-specific polyclonal and monoclonal antisera for identifying species of lutjanid fishes at early life history stages. C1 UNIV MIAMI,ROSENSTIEL SCH MARINE & ATMOSPHER SCI,MIAMI,FL 33149. NOAA,NATL MARINE FISHERIES SERV,SE FISHERIES SCI CTR,MIAMI,FL 33149. RP Schultz, DR (reprint author), UNIV MIAMI,SCH MED,DEPT MED,MIAMI,FL 33101, USA. NR 26 TC 4 Z9 4 U1 0 U2 1 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD OCT PY 1996 VL 94 IS 4 BP 734 EP 742 PG 9 WC Fisheries SC Fisheries GA VM745 UT WOS:A1996VM74500012 ER PT J AU Sheridan, P AF Sheridan, P TI Forecasting the fishery for pink shrimp, Penaeus duorarum, on the Tortugas Grounds, Florida SO FISHERY BULLETIN LA English DT Article ID PRAWN METAPENAEUS-MACLEAYI; WINTER TEMPERATURE; NORTH-CAROLINA; RIVER-REGION; BAY; LANDINGS; RECRUITMENT; ABUNDANCE; AUSTRALIA AB In this report I review the biology of and fishery for pink shrimp, Penaeus duorarum, harvested from the Tortugas Grounds off southwest Florida, and present models used to forecast annual pink shrimp landings in this area. Pink shrimp spawn all year, and larvae recruit to nurseries in the seagrass-mangrove ecosystem surrounding Everglades National Park and Florida Bay. Juveniles move out of the nurseries all year, but catch per unit of effort for smallest size classes generally exhibits March and September peaks. Total landings usually rise sharply in November and taper off after April. The fishery was relatively stable during 1960-85, averaging 4,350 metric tons annually, but it has shown a singular decline and potential recovery since 1985. In 1987, I began forecasting annual landings by using multiple regression analyses of fishery catch statistics and environmental factors that could affect survival, growth, and recruitment. Potential predictor variables from May through October were investigated in order to release a timely annual forecast by November. Each year, the updated data set from 1966 onwards was examined to derive the ''best'' forecast models. Important predictor variables included indices of fishing activity during the waning months of the fishery (May-July) and surface and ground water levels within Everglades National Park during June-September. Forecasts were within +/-20% of actual landings for five of eight years, whereas forecast direction (increase or decrease over the prior year) was usually correct. Cause-effect relationships between predictor variables and pink shrimp recruitment to the fishery remain to be determined. RP Sheridan, P (reprint author), NOAA,NATL MARINE FISHERIES SERV,SE FISHERIES SCI CTR,4700 AVE U,GALVESTON,TX 77551, USA. NR 58 TC 25 Z9 26 U1 0 U2 5 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD OCT PY 1996 VL 94 IS 4 BP 743 EP 755 PG 13 WC Fisheries SC Fisheries GA VM745 UT WOS:A1996VM74500013 ER PT J AU Yoklavich, MM Loeb, VJ Nishimoto, M Daly, B AF Yoklavich, MM Loeb, VJ Nishimoto, M Daly, B TI Nearshore assemblages of larval rockfishes and their physical environment off central California during an extended El Nino event, 1991-1993 SO FISHERY BULLETIN LA English DT Article ID MONTEREY BAY; PELAGIC FISH; SEBASTES; COAST; ICHTHYOPLANKTON; PACIFIC; GROWTH; RECRUITMENT; CIRCULATION; VARIABILITY AB Rockfish are among the most prevalent members of nearshore ichthyoplankton assemblages off central California, yet their abundance varies greatly from year to year. Warm events, like El Nino, can have pronounced effects on the success of a year class. We evaluate distribution, abundance, and species composition of rockfish larvae on small spatial and temporal scales in the upwelling center north of Monterey Bay during an extended El Nino (December 1991 through June 1993) relative to regional hydrography. Anomalously warm, low-salinity water to depths greater than 50 m during much of our study was indicative of an onshore displacement of the California Current; Upwelling was reduced and delayed relative to other years. The two years differed, however, in the intensity, duration, frequency, and direction of wind events. Larval rockfish abundance was similar in both years of the El Nino, peaking in early February, and was among the highest when compared with estimates from CalCOFI surveys off central California (1951-84). Using larval ages, we determined that median birthdates of shortbelly rockfish were in early- to mid-February both years. Growth rates of larval shortbelly rockfish did not differ among months or between years. Relative to 1993, rockfish larvae were more abundant; and sizes of larval shortbelly were significantly greater at onshore stations in 1992. This coincided with onshore advection of water during the onset of the El Nino, suggesting retention of larvae nearshore. Initiation of upwelling in March and April 1993 and fewer larvae at onshore stations are indicative of greater offshore transport during the second year. Juvenile rockfishes were extremely rare in summer of 1992; in 1993 they were twenty times more abundant and larger. Surviving juvenile shortbelly rockfish were born late during both years; upwelling occurred coincidentally during this period in 1993 but not in 1992. We suggest that substantially higher survival and recruitment of juvenile rockfishes in 1993 was due to increased offshore transport and perhaps lower predation during the larval stages. C1 MOSS LANDING MARINE LABS,MOSS LANDING,CA 95039. RP Yoklavich, MM (reprint author), NOAA,NATL MARINE FISHERIES SERV,SW FISHERIES SCI CTR,PACIFIC FISHERIES ENVIRONM GRP,PACIFIC GROVE,CA 93950, USA. NR 66 TC 41 Z9 41 U1 1 U2 4 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD OCT PY 1996 VL 94 IS 4 BP 766 EP 782 PG 17 WC Fisheries SC Fisheries GA VM745 UT WOS:A1996VM74500015 ER PT J AU Wheat, CG Feely, RA Mottl, MJ AF Wheat, CG Feely, RA Mottl, MJ TI Phosphate removal by oceanic hydrothermal processes: An update of the phosphorus budget in the oceans SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID DE-FUCA RIDGE; EAST-PACIFIC-RISE; MID-ATLANTIC RIDGE; CONTINENTAL-MARGIN SEDIMENTS; RARE-EARTH ELEMENTS; MARINE-SEDIMENTS; INTERSTITIAL WATERS; IRON OXYHYDROXIDES; CHEMICAL PROCESSES; NORTHEAST PACIFIC AB We present a compilation of dissolved phosphate and solid-phase P data from the oceanic crust to evaluate the effects of hydrothermal processes on the oceanic budget of P. Concentrations of phosphate in fluids that emanate from ridge-axis hydrothermal systems are less than that in bottom seawater. The extent of removal in these fluids is at least 30% and in some hydrothermal systems dissolved phosphate is removed completely from the circulating fluid. Evidence for the removal of phosphate in each of six ridge flank hydrothermal systems is based on systematic variations in porewater profiles of phosphate and speeds of porewater flow. The extent of removal is >80% in these ridge-flank systems. These removal processes are recorded in the basaltic crust as an increase in P concentration that coincides with an increase in extent of alteration and content of ferric iron. Phosphate also is removed in hydrothermal plumes by coprecipitation with Fe oxyhydroxide particles, which eventually deposit on the seafloor. Each of these hydrothermal processes results in a flux of P into the oceanic crust. Bottom seawater flow through ridge-axis hydrothermal systems removes at most 0.4% of the preindustrial dissolved riverine flux of P, while ridge flanks remove at least 5%, but less than 50% of the dissolved riverine flux, consistent with P data from Deep Sea Drilling Project (DSDP) Sites 417 and 418. Removal of phosphate by coprecipitation with Fe-rich particles in hydrothermal plumes along ridge axes accounts for 18-33% of the dissolved riverine flux. Thus, hydrothermal systems remove about 50% of the preindustrial dissolved riverine flux of phosphate. We have included these new estimates in a revised budget for oceanic P. C1 UNIV ALASKA FAIRBANKS,INST MARINE SCI,FAIRBANKS,AK 99775. NOAA,PACIFIC MARINE ENVIRONM LAB,SEATTLE,WA 98115. UNIV HAWAII,DEPT OCEANOG,HONOLULU,HI 96822. NR 95 TC 94 Z9 98 U1 2 U2 19 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD OCT PY 1996 VL 60 IS 19 BP 3593 EP 3608 DI 10.1016/0016-7037(96)00189-5 PG 16 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA WB001 UT WOS:A1996WB00100004 ER PT J AU Dlugokencky, EJ Dutton, EG Novelli, PC Tans, PP Masarie, KA Lantz, KO Madronich, S AF Dlugokencky, EJ Dutton, EG Novelli, PC Tans, PP Masarie, KA Lantz, KO Madronich, S TI Changes in CH4 and CO growth rates after the eruption of Mt Pinatubo and their link with changes in tropical tropospheric UV flux SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID ABSORPTION CROSS-SECTIONS; ATMOSPHERIC METHANE; NORTHERN-HEMISPHERE; CARBON-MONOXIDE; MOUNT-PINATUBO; OZONE CHANGES; CLOUDS; IMPACT AB Trace gas measurements from air samples collected weekly at a globally distributed network of sampling sites revealed sharp increases in the growth Fates of CH4 and CO in the tropics and high southern latitudes immediately following the eruption of Mt. Pinatubo on June 15, 1991. The eruption emitted similar to 20 Mt SO2 into the lower stratosphere. Calculations made with a radiative transfer model show that UV actinic flux in the wavelength region 290-330 nm was attenuated by similar to 12% immediately after the eruption due to direct absorption by SO2, and that it was perturbed for up to 1 year after the eruption due to scattering by sulfate aerosols. We suggest that the decreased UV flux decreased the Steady-state [OH] and led to the observed anomalously large growth rates for CH4 and CO during late-1991 and early-1992. C1 NATL CTR ATMOSPHER RES,DIV ATMOSPHER CHEM,BOULDER,CO 80307. RP Dlugokencky, EJ (reprint author), NOAA,CLIMATE MONITORING & DIAGNOST LAB,325 BROADWAY,R-E-CG1,BOULDER,CO 80303, USA. RI Madronich, Sasha/D-3284-2015 OI Madronich, Sasha/0000-0003-0983-1313 NR 23 TC 79 Z9 83 U1 1 U2 12 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD OCT 1 PY 1996 VL 23 IS 20 BP 2761 EP 2764 DI 10.1029/96GL02638 PG 4 WC Geosciences, Multidisciplinary SC Geology GA VL370 UT WOS:A1996VL37000012 ER PT J AU Shang, EC Wang, YY Sun, SB AF Shang, EC Wang, YY Sun, SB TI Inversion in shallow-water using the WKB modal condition SO IEEE JOURNAL OF OCEANIC ENGINEERING LA English DT Article ID SOURCE LOCALIZATION; OCEAN-BOTTOM; PARAMETERS; SOUND; FIELD AB In this paper, we propose an efficient scheme for extracting the complex bottom reflection coefficient (phase and amplitude) in a shallow water waveguide by using the WKB modal condition. The input data are the measured modal wavenumber (k(m)) and the modal attenuation (beta(m)). The main advantages of this scheme are: 1) it is efficient, because there are no replica calculations as in the conventional matched field processing (MFP) scheme, 2) the inverted error induced by the ''noise'' of the contaminated data can be estimated analytically, and 3) the impact of the environmental (SSP) mismatch can also be estimated analytically. Numerical simulations illustrate that the proposed scheme works well in different scenarios of shallow water waveguides. C1 NOAA,ENVIRONM TECHNOL LAB,BOULDER,CO 80303. TECH UNIV DENMARK,DEPT IND ACOUST,DK-2800 LYNGBY,DENMARK. RP Shang, EC (reprint author), UNIV COLORADO,CIRES,BOULDER,CO 80309, USA. NR 27 TC 2 Z9 4 U1 1 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0364-9059 J9 IEEE J OCEANIC ENG JI IEEE J. Ocean. Eng. PD OCT PY 1996 VL 21 IS 4 BP 432 EP 439 DI 10.1109/48.544054 PG 8 WC Engineering, Civil; Engineering, Ocean; Engineering, Electrical & Electronic; Oceanography SC Engineering; Oceanography GA VU550 UT WOS:A1996VU55000012 ER PT J AU Tachikawa, M Evenson, KM Zink, LR Maki, AG AF Tachikawa, M Evenson, KM Zink, LR Maki, AG TI Frequency measurements of 9- and 10-mu m N2O laser transitions SO IEEE JOURNAL OF QUANTUM ELECTRONICS LA English DT Article ID HOT-BAND; ROTATIONAL TRANSITIONS; MOLECULAR-CONSTANTS; SPECTRUM; CM-1; PARAMETERS; CO2-LASER; BEAM AB We have measured frequencies of N2O transitions by heterodyning sub-Doppler Buorescence-stabilized N2O laser radiation with that from a reference CO2 laser, A high-resolution cavity incorporates a ribbed tube and a highly reflective grating, permitting the CW oscillation of both the 10(0)0-2(0)0 9-mu m and the 10(0)0-00(0)1 10 -mu m regular bands, This is the first sub-Doppler frequency measurement of the 9-mu m band. The accuracy in the determination of the rotational constants for both hands has been improved by an order of magnitude, and calculated transition frequencies are presented. RP Tachikawa, M (reprint author), NATL INST STAND & TECHNOL,DIV TIME & FREQUENCY,BOULDER,CO 80303, USA. NR 23 TC 7 Z9 7 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9197 J9 IEEE J QUANTUM ELECT JI IEEE J. Quantum Electron. PD OCT PY 1996 VL 32 IS 10 BP 1732 EP 1736 DI 10.1109/3.538777 PG 5 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA VK651 UT WOS:A1996VK65100004 ER PT J AU Stubenrauch, CF Newell, AC Repjar, AG MacReynolds, K Tamura, DT Larsen, FH Lemanczyk, J Behe, R Portier, G Zehren, JC Hollmann, H Hunter, JD Gentle, DG deVreede, JPM AF Stubenrauch, CF Newell, AC Repjar, AG MacReynolds, K Tamura, DT Larsen, FH Lemanczyk, J Behe, R Portier, G Zehren, JC Hollmann, H Hunter, JD Gentle, DG deVreede, JPM TI International inter-comparison of horn gain at X-band SO IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION LA English DT Article AB An international intercomparison of horn gain and polarization measurements at X-band has recently been completed. There were seven participating laboratories with the National institute of Standards and Technology serving as the pilot laboratory, Two X-band pyramidal standard gain horns with a nominal gain of 22 dB served as the traveling standards, Quantities measured included on-axis fixed frequency gain at 8, 10, and 12 GHz, swept frequency gain between 8-12 GHz and polarization characteristics at the three fixed frequencies, All laboratories performed the fixed frequency-gain measurements, The swept-frequency and polarization measurements were optional, with four laboratories performing swept-frequency measurements and three laboratories measuring polarization. The result of the gain measurements generally agreed within the reported uncertainties which were of the order of 0.1 dB or less. C1 TECH UNIV DENMARK,DK-2800 LYNGBY,DENMARK. CTR NATL ETUD TELECOMMUN,F-92131 ISSY MOULINEAUX,FRANCE. DEUTSCH TELECOM AG,FORSCH & TECHNOL ZENTRUM,DARMSTADT,GERMANY. CSIRO,W LINFIELD,NSW,AUSTRALIA. NATL PHYS LAB,TEDDINGTON TW11 0LW,MIDDX,ENGLAND. VAN SWINDEN LAB,DELFT,NETHERLANDS. RP Stubenrauch, CF (reprint author), NATL INST STAND & TECHNOL,BOULDER,CO 80303, USA. NR 15 TC 13 Z9 14 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-926X J9 IEEE T ANTENN PROPAG JI IEEE Trans. Antennas Propag. PD OCT PY 1996 VL 44 IS 10 BP 1367 EP 1374 DI 10.1109/8.537331 PG 8 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA VK650 UT WOS:A1996VK65000008 ER PT J AU Zimmerman, NM AF Zimmerman, NM TI Capacitors with very low loss: Cryogenic vacuum-gap capacitors SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article ID ELECTRON AB We report on measurements of capacitors with about 1 pF of capacitance, which have unmeasurably small leakage at very low frequencies, placing a lower bound of about 10(19)Omega on the parallel resistance at an effective frequency of 1 mHz, These measurements are made possible by two themes: the use of vacuum-gap capacitors (i.e., no dielectric material, operated in vacuum), and detection of leakage using single electron tunneling (SET) electrometers, which have very high input impedance, We also report on good achieved results in time stability and lack of frequency and voltage dependence. RP Zimmerman, NM (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 10 TC 25 Z9 25 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD OCT PY 1996 VL 45 IS 5 BP 841 EP 846 DI 10.1109/19.536699 PG 6 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA VH477 UT WOS:A1996VH47700001 ER PT J AU Yang, JC Pitts, WM Breuel, BD Grosshandler, WL Cleveland, WG AF Yang, JC Pitts, WM Breuel, BD Grosshandler, WL Cleveland, WG TI Rapid discharge of a fire suppressing agent SO INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER LA English DT Article AB This paper describes an experimental method to study the rapid discharge of a fire suppressant (C3F8) from a pressurized vessel. Experimental observations inside and at the exit of the vessel were made using high-speed photography. Boiling was not observed inside the vessel during discharges. A simple mathematical model was developed to predict the liquid depletion level and is compared to the experimental measurements. C1 NATL INST STAND & TECHNOL, CHEM SCI & TECHNOL LAB, GAITHERSBURG, MD 20899 USA. RP Yang, JC (reprint author), NATL INST STAND & TECHNOL, BLDG & FIRE RES LAB, GAITHERSBURG, MD 20899 USA. NR 17 TC 4 Z9 4 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0735-1933 J9 INT COMMUN HEAT MASS JI Int. Commun. Heat Mass Transf. PD OCT PY 1996 VL 23 IS 6 BP 835 EP 844 DI 10.1016/0735-1933(96)00066-8 PG 10 WC Thermodynamics; Mechanics SC Thermodynamics; Mechanics GA VB935 UT WOS:A1996VB93500008 ER PT J AU Eberhard, J Howard, CJ AF Eberhard, J Howard, CJ TI Temperature-dependent kinetics studies of the reactions of C2H5O2 and n-C3H7O2 radicals with NO SO INTERNATIONAL JOURNAL OF CHEMICAL KINETICS LA English DT Article ID ALKYL NITRATE FORMATION; RATE CONSTANTS; GAS-PHASE; ALKANES; 295-K AB The rate coefficients for the gas-phase reactions of C2H5O2 and n-C3H7O2 radicals with NO have been measured over the temperature range of (201-403) K using chemical ionization mass spectrometric detection of the peroxy radical, The alkyl peroxy radicals were generated by reacting alkyl radicals with O-2, where the alkyl radicals were produced through the pyrolysis of a larger alkyl nitrite. In some cases C2H5 radicals were generated through the dissociation of iodoethane in a low-power radio Frequency discharge. The discharge source was also tested for the i-C3H7O2 + NO reaction, yielding k(298 K) = (9.1 +/- 1.5) x 10(-12) cm(3) molecule(-1) s(-1), in excellent agreement with our previous determination. The temperature dependent rate s coefficients were found to be k(T) = (2.6 +/- 0.4) x 10(-12) exp{(380 +/- 70)/T} cm(3) molecule(-1) s(-1) and = 12.9 +/- 0.5) x 10(-12) exp{(350 +/- 60)T} cm(3) molecule(-1) s(-1) for the reactions of C2H5O2 and n-C3H7O2 radicals with NO, respectively. The rate coefficients at 298 K derived from these Arrhenius expressions are k = (9.3 +/- 1.6) x 10(-12) cm(3) molecule(-1) s(-1) for C2H5O2 radicals and k = (9.4 +/- 1.6) x 10(-12) cm(3) molecule(-1) s(-1) for n-C2H5O2 radicals. (C) 1996 John Wiley & Sons, Inc. C1 NOAA,ENVIRONM RES LABS,AERON LAB,BOULDER,CO 80303. NR 21 TC 30 Z9 30 U1 0 U2 10 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0538-8066 J9 INT J CHEM KINET JI Int. J. Chem. Kinet. PD OCT PY 1996 VL 28 IS 10 BP 731 EP 740 DI 10.1002/(SICI)1097-4601(1996)28:10<731::AID-KIN3>3.0.CO;2-O PG 10 WC Chemistry, Physical SC Chemistry GA VJ073 UT WOS:A1996VJ07300003 ER PT J AU Gallo, KP Tarpley, JD AF Gallo, KP Tarpley, JD TI The comparison of vegetation index and surface temperature composites for urban heat-island analysis SO INTERNATIONAL JOURNAL OF REMOTE SENSING LA English DT Article ID AVHRR DATA AB Relationships between urban-rural differences in minimum (in situ) air temperature (T-min), normalized difference vegetation index (NDVI), and apparent surface radiant temperature (T-sfc) were examined for 28 cities in the U.S.A. from 28 June through to 8 August 1991. Composites based on NDVI and thermal-IR data, and consistency in urban-rural differences in NDVI and T-sfc were examined. The urban-rural differences in T-sfc, whether based on an NDVI composite or a composite based on thermal-IR data, were not as consistent as the urban-rural differences in NDVI. The composite process utilized, based on NDVI or thermal-IR data, did not appear to contribute to the generally low correlation between urban-rural differences in T-min and T-sfc observed in previous studies. RP Gallo, KP (reprint author), NOAA,NESDIS,OFF RES & APPL,WASHINGTON,DC 20233, USA. RI Gallo, Kevin P./F-5588-2010 NR 8 TC 37 Z9 46 U1 2 U2 10 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0143-1161 J9 INT J REMOTE SENS JI Int. J. Remote Sens. PD OCT PY 1996 VL 17 IS 15 BP 3071 EP 3076 PG 6 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA VJ564 UT WOS:A1996VJ56400013 ER PT J AU Mychajluk, G Manoochehri, S Parnas, RS AF Mychajluk, G Manoochehri, S Parnas, RS TI Resin transfer molding process optimization for minimum cycle-time SO JOURNAL OF ADVANCED MATERIALS LA English DT Article ID FILLING SIMULATION; IMPREGNATION; MEDIA AB A minimum cycle-time process optimization for Resin Transfer Molding (RTM) is presented. The optimization model is developed using an integrated approach which combines polymer flow and cure kinetics with process cycle-time. The optimization problem uses constraint equations to establish a feasible processing range represented by process contour maps. This constraint-based model captures limitations imposed by allowable processing conditions defined by molding temperatures and pressures during the injection and cure cycles. These constraints are used to develop an integrated process model that captures relationships between physical and chemical processes required for manufacturing of the part. For example, the relationship between resin injection pressures and void formation is studied. C1 NIST,DIV POLYMERS,GAITHERSBURG,MD 20899. RP Mychajluk, G (reprint author), STEVENS INST TECHNOL,DEPT MECH ENGN,HOBOKEN,NJ 07030, USA. NR 19 TC 6 Z9 6 U1 1 U2 1 PU SAMPE PUBLISHERS PI COVINA PA 1161 PARKVIEW DRIVE, COVINA, CA 91722 SN 1070-9789 J9 J ADV MATER JI J. Adv. Mater. PD OCT PY 1996 VL 28 IS 1 BP 9 EP 18 PG 10 WC Materials Science, Multidisciplinary SC Materials Science GA VY573 UT WOS:A1996VY57300002 ER PT J AU Katul, GG Finkelstein, PL Clarke, JF Ellestad, TG AF Katul, GG Finkelstein, PL Clarke, JF Ellestad, TG TI An investigation of the conditional sampling method used to estimate fluxes of active, reactive, and passive scalars SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID RELAXED EDDY-ACCUMULATION; INFERENTIAL MEASUREMENT TECHNIQUES; ORTHONORMAL WAVELET ANALYSIS; SURFACE-LAYER TURBULENCE; SENSIBLE HEAT-FLUX; PROBABILITY DENSITY; DRY DEPOSITION; FOREST CANOPY; DESIGN; SYSTEM AB The conditional sampling flux measurement technique was evaluated for four scalars (temperature, water vapor, ozone, and carbon dioxide) by comparison with direct eddy correlation measurements at two sites. The empirical constant beta relating the turbulent flux to the accumulated concentration difference between updrafts and downdrafts was computed from 10-Hz turbulence measurements. Comparison between the simulated relaxed eddy accumulation flux formulation and the eddy correlation measurements allowed the direct determination of beta for all four scalars. The beta models previously proposed overpredicted the measured beta by about 8%-10%. It was found that a mean beta = 0.58 reproduced the eddy correlation measurements independent of the scalar type being analyzed, roughness and atmospheric stability conditions, in agreement with previous studies. The role of energy-containing eddy motion in the deviations between the measured and predicted beta was considered using orthonormal wavelet expansion in conjunction with a wavelet shrinkage approach. It was demonstrated that the energy-containing large eddy motion contributed to a reduction in beta when compared to the predicted beta. Finally, the deadband vertical velocity effects were also considered and found to reduce beta exponentially, in agreement with other studies. C1 NOAA,AIR RESOURCES LAB,ATMOSPHER SCI MODELING DIV,RES TRIANGLE PK,NC. US EPA,NATL EXPOSURE RES LAB,RES TRIANGLE PK,NC 27711. RP Katul, GG (reprint author), DUKE UNIV,SCH ENVIRONM,DURHAM,NC 27708, USA. RI Katul, Gabriel/A-7210-2008 OI Katul, Gabriel/0000-0001-9768-3693 NR 53 TC 48 Z9 49 U1 1 U2 7 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD OCT PY 1996 VL 35 IS 10 BP 1835 EP 1845 DI 10.1175/1520-0450(1996)035<1835:AIOTCS>2.0.CO;2 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VP281 UT WOS:A1996VP28100017 ER PT J AU Bennett, HS AF Bennett, HS TI Majority and minority electron and hole mobilities in heavily doped gallium aluminum arsenide SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID P-TYPE GAAS; SCATTERING; SILICON; SIMULATION AB The majority electron and minority hole mobilities were calculated in Ga1-yAlyAs for donor densities between 10(16) and 10(19) cm(-3). Similarly, the majority hole and minority electron mobilities were calculated for acceptor densities between 10(16) and 10(20) cm(-3). The mole fraction of AlAs, y, varies between 0.0 and 0.3 in these calculations. All the important scattering mechanisms have been included. The ionized impurity and carrier-carrier scattering processes were treated with a quantum-mechanical, phase-shift analysis. These calculations are the first to use a phase-shift analysis for minority carriers scattering from majority carriers in ternary compounds such as Ga1-yAlyAs. The results are in good agreement with experiment for majority mobilities and predict that at high dopant densities minority mobilities should increase with increasing dopant density for a short range of densities. This effect occurs because of the reduction of plasmon scattering and the removal of carriers from carrier-carrier scattering due to the Pauli exclusion principle. These calculations do not treat the density-of-state modifications due to heavy doping, which should have only a small effect on the mobility al room temperature. The results are important for device modeling because of the need to have physically reasonable values for minority mobilities when simulating die electrical behavior of heterojunction bipolar transistors. RP Bennett, HS (reprint author), NATL INST STAND & TECHNOL,DIV SEMICOND ELECT,GAITHERSBURG,MD 20899, USA. NR 39 TC 13 Z9 13 U1 1 U2 15 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD OCT 1 PY 1996 VL 80 IS 7 BP 3844 EP 3853 DI 10.1063/1.363339 PG 10 WC Physics, Applied SC Physics GA VL801 UT WOS:A1996VL80100036 ER PT J AU Straka, JM Rasmussen, EN Fredrickson, SE AF Straka, JM Rasmussen, EN Fredrickson, SE TI A mobile mesonet for finescale meteorological observations SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID SEVERE THUNDERSTORMS; TOTO AB A mobile weather observing system (mobile mesonet) was designed to augment existing meteorological networks in the study of severe local storms and other mesoscale weather phenomena in conjunction with the Verification of the Origins of Rotation in Tornadoes Experiment (VORTEX). Fifteen mobile mesonet units were built, each consisting of meteorological instruments mounted on standard automobiles, for high temporal and spatial resolution observations. While the most accurate measurements are possible from stationary mobile mesonet vehicles, accurate observations also are possible from moving vehicles. The mobile mesonet instruments measure pressure (600-1100 mb), temperature (-33 degrees to 48 degrees C), relative humidity (0%-100%), and wind direction and speed (0 degrees-360 degrees and 0-60 m s(-1)). Onboard each vehicle, a Global Positioning System (GPS) receiver and a flux-gate compass obtain universal time, vehicle location (latitude, longitude, altitude), and vehicle heading and speed. A standard laptop computer stores data, computes derived variables, and provides real-time data display. Instrument compatibility with the Oklahoma Mesonet allows for high-quality instrument calibration and maintenance. The purpose of this paper is to provide a technical overview of the mobile mesonet system. The rationale for choice of instrumentation and justification for method of exposure are discussed. The performance of the mobile mesonet is demonstrated with two examples of data collected during VORTEX-1994 and comparisons with data from an Oklahoma Mesonet site. C1 NATL SEVERE STORMS LAB,NORMAN,OK 73069. RP Straka, JM (reprint author), UNIV OKLAHOMA,SCH METEOROL,ENERGY CTR,100 E BOYD ST,RM 1310,NORMAN,OK 73019, USA. NR 26 TC 81 Z9 81 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD OCT PY 1996 VL 13 IS 5 BP 921 EP 936 DI 10.1175/1520-0426(1996)013<0921:AMMFFM>2.0.CO;2 PG 16 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA VN010 UT WOS:A1996VN01000001 ER PT J AU Cifelli, R Rutledge, SA Boccippio, DJ Matejka, T AF Cifelli, R Rutledge, SA Boccippio, DJ Matejka, T TI Horizontal divergence and vertical velocity retrievals from Doppler radar and wind profiler observations SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID MESOSCALE CONVECTIVE SYSTEMS; 10-11 JUNE 1985; SQUALL LINE; AIR MOTIONS; PRECIPITATION; LATITUDE; OKLAHOMA; MONSOON AB Vertical motion profiles can be diagnosed with the mass continuity equation using horizontal divergence fields derived from various single-Doppler radar techniques such as EVAD (extended velocity-azimuth display), CEVAD (concurrent extended velocity-azimuth display), and VVP (volume velocity processing). These methods allow for the retrieval of mesoscale air motions in precipitating regions when the wind field is relatively homogeneous. In contrast, VHF wind profiler data can provide a direct measurement of vertical motion, albeit across a much smaller domain compared to the single-Doppler radar techniques. In this study, we compare horizontal divergence and vertical morion patterns derived from the various single-Doppler methods with those obtained from VHF profiler data. The diagnosed profiles of horizontal divergence and vertical velocity from the single-Doppler (scanning radar) techniques are in qualitative agreement in the lower troposphere but often exhibit large variability at higher levels, Because of less stringent radar echo requirements, the VVP technique often analyzed data above the top of the EVAD-CEVAD analysis domain, resulting in a deeper layer of upper-level divergence. The CEVAD technique often produced a deeper and larger region of upward motion despite similar profiles of divergence, probably due to the CEVAD top boundary condition specification of particle terminal fall speed as opposed to the vertical air motion, as well as to the adjustment procedure employed during the regression solution. The wind profiler data showed much larger vertical gradients and magnitudes of divergence and vertical velocity when averaged over the same time interval required to collect data for a single-Doppler retrieval, However, when all the available data were composited, the high-frequency variability in the wind profiler retrievals was reduced resulting in relatively good agreement between all analysis methods, The wind profiler usually sampled vertical motion (divergence) several kilometers above the single-Doppler retrievals, which the authors attribute to the stringent precipitation echo coverage requirements imposed by the scanning radar analysis techniques, thus limiting their vertical extent near echo top. C1 COLORADO STATE UNIV,DEPT ATMOSPHER SCI,FT COLLINS,CO 80523. MIT,CTR METEOROL & PHYS OCEANOG,CAMBRIDGE,MA 02139. NOAA,ENVIRONM RES LAB,NATL SEVERE STORMS LAB,MESOSCALE RES DIV,BOULDER,CO 80303. NR 40 TC 12 Z9 13 U1 1 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD OCT PY 1996 VL 13 IS 5 BP 948 EP 966 DI 10.1175/1520-0426(1996)013<0948:HDAVVR>2.0.CO;2 PG 19 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA VN010 UT WOS:A1996VN01000003 ER PT J AU Anderson, TL Covert, DS Marshall, SF Laucks, ML Charlson, RJ Waggoner, AP Ogren, JA Caldow, R Holm, RL Quant, FR Sem, GJ Wiedensohler, A Ahlquist, NA Bates, TS AF Anderson, TL Covert, DS Marshall, SF Laucks, ML Charlson, RJ Waggoner, AP Ogren, JA Caldow, R Holm, RL Quant, FR Sem, GJ Wiedensohler, A Ahlquist, NA Bates, TS TI Performance characteristics of a high-sensitivity, three-wavelength, total scatter/backscatter nephelometer SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID SCATTERING AB As designed in the 1940s by Beuttell and Brewer, the integrating nephelometer offers a direct method of measuring light scattering by airborne particles without assumptions about particle composition, shape, or physical state. A large number of such instruments have been deployed; however, only a limited number of validation experiments have been attempted. This paper reports a set of closure experiments in which a gas-calibrated nephelometer is used to measure the scattering coefficient of laboratory-generated particles of known size and refractive index. Specifically, it evaluates the performance of a high-sensitivity, three-wavelength, total scatter/backscatter integrating nephelometer (TSI, Inc., model 3563). Sources of uncertainty associated with the gas-calibration procedure, with photon-counting statistics, and with nonidealities in wavelength and angular sensitivity are investigated. Tests with particle-free gases indicate that noise levels are well predicted by photon-counting statistics and that the nephelometer response is linear over a wide range of scattering coefficients. Tests with particles show average discrepancies between measured and predicted scattering of 4%-7%. Error analysis indicates that these discrepancies are within experimental uncertainty, which was dominated by particle generation uncertainty. The simulation of nephelometer response, which is validated by these tests, is used to show that errors arising from nephelometer nonidealities are less than 10% for accumulation-mode or smaller particles (i.e., size distributions for which the volume mean diameter is 0.4 mu m or less) and that significant differences exist between the total scatter and backscatter uncertainties. Based on these findings, appropriate applications of the model 3563 nephelometer are discussed. C1 NOAA,CLIMATE MONITORING & DIAGNOST LAB,BOULDER,CO 80303. TSI INC,ST PAUL,MN. INST TROPOSPHARENFORSCH EV,LEIPZIG,GERMANY. FLOSACN INSTRUMENT CO INC,SEATTLE,WA. NOAA,PACIFIC MARINE ENVIRONM LAB,SEATTLE,WA 98115. RP Anderson, TL (reprint author), UNIV WASHINGTON,DEPT ATMOSPHER SCI,BOX 351640,SEATTLE,WA 98195, USA. RI Ogren, John/M-8255-2015; Bates, Timothy/L-6080-2016 OI Ogren, John/0000-0002-7895-9583; NR 22 TC 317 Z9 326 U1 3 U2 31 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD OCT PY 1996 VL 13 IS 5 BP 967 EP 986 DI 10.1175/1520-0426(1996)013<0967:PCOAHS>2.0.CO;2 PG 20 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA VN010 UT WOS:A1996VN01000004 ER PT J AU Liu, PC Miller, GS AF Liu, PC Miller, GS TI Wavelet transforms and ocean current data analysis SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID TIME-FREQUENCY LOCALIZATION; PROPAGATION; SIGNAL; SERIES AB The recently advanced approach of wavelet transforms is applied to the analysis of ocean currents. The conventional analyses of time series in the frequency domain can be readily generalized to the frequency and time domain using wavelet transforms. An application of wavelet analysis to a set of observed current data acquired during the spring of 1991 in Lake Michigan shows some significant time-localized characteristics that would not be detected using the traditional Fourier transform approach. RP Liu, PC (reprint author), NOAA,GREAT LAKES ENVIRONM RES LAB,2205 COMMONWEALTH BLVD,ANN ARBOR,MI 48105, USA. NR 15 TC 26 Z9 27 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD OCT PY 1996 VL 13 IS 5 BP 1090 EP 1099 DI 10.1175/1520-0426(1996)013<1090:WTAOCD>2.0.CO;2 PG 10 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA VN010 UT WOS:A1996VN01000011 ER PT J AU Hamilton, K AF Hamilton, K TI Comprehensive meteorological modelling of the middle atmosphere: A tutorial review SO JOURNAL OF ATMOSPHERIC AND TERRESTRIAL PHYSICS LA English DT Article; Proceedings Paper CT 1995 Coupling, Energetics, and Dynamics of Atmospheric Regions (CEDAR) Workshop CY JUN, 1995 CL BOULDER, CO ID GENERAL-CIRCULATION MODEL; GRAVITY-WAVE DRAG; QUASI-BIENNIAL OSCILLATION; SEMIANNUAL OSCILLATION; MEAN FLOW; PLANETARY-WAVES; MOMENTUM FLUXES; STRATOSPHERIC CIRCULATION; NORTHERN HEMISPHERE; RAYLEIGH LIDAR AB This paper reviews the current state of comprehensive, three-dimensional, time-dependent modelling of the circulation in the middle and upper atmosphere from a meteorologist's perspective. The paper begins with a consideration of the various components of a comprehensive model (or general circulation model, GCM), including treatments of processes that can be explicitly resolved and those that occur on scales too small to resolve (and that must be parameterized). The typical performance of GCMs in simulating the tropospheric climate is discussed. Then some important background on current ideas concerning the general circulation of the stratosphere and mesosphere is presented. In particular, the transformed-Eulerian mean flow formalism, the role of vertically-propagating internal gravity waves in driving the large-scale circulation, and the notion of a stratospheric surf zone are all briefly reviewed. Using this background as a guide, some middle atmospheric GCM results are discussed, with a focus on simulations made recently with the GFDL 'SKYHI' troposphere-stratosphere-mesosphere GCM. The presentation attempts to emphasize the interaction between theory and comprehensive modelling. Many theoretical notions cannot be confirmed in detail from observations of the real atmosphere due to the various limitations in the observational methods, but can be very completely examined in GCMs in which every atmospheric variable is known perfectly (within the limits of the numerical methods). it will be shown that our understanding of both the role of gravity waves in the general circulation and the nature of the stratospheric surf zone has benefited from analysis of GCM results. From the point of view of the upper atmosphere, one of the most interesting aspects of GCMs is their ability to generate a self-consistent field of upward-propagating gravity waves. This paper concludes with a discussion of the gravity wave field in the middle atmosphere of GCMs. Comparisons of the explicitly-resolved gravity wave field in the SKYHI model with observations are quite encouraging, and it seems that the model is capable of producing a gravity wave field with many realistic features. However, the simulated horizontal spectrum of the eddy momentum fluxes associated with the waves is quite shallow, suggesting that much of the spectrum that is important for maintaining the mean circulation is not explicitly resolvable in current GCMs. A brief discussion of current efforts at parameterizing the mean flow effects of the unresolvable gravity waves is presented. Copyright (C) 1996 Elsevier Science Ltd RP Hamilton, K (reprint author), PRINCETON UNIV, NOAA, GEOPHYS FLUID DYNAM LAB, POB 308, PRINCETON, NJ 08542 USA. NR 111 TC 48 Z9 48 U1 1 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0021-9169 J9 J ATMOS TERR PHYS JI J. Atmos. Terr. Phys. PD OCT PY 1996 VL 58 IS 14 BP 1591 EP 1627 DI 10.1016/0021-9169(96)00028-1 PG 37 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UW181 UT WOS:A1996UW18100005 ER PT J AU Kato, S deGouw, JA Lin, CD Bierbaum, VM Leone, SR AF Kato, S deGouw, JA Lin, CD Bierbaum, VM Leone, SR TI Vibrational enhancement of the charge transfer rate constant of N-2(+)(v=0-4) with Kr at thermal energies SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ION-MOLECULE REACTIONS; LASER-INDUCED FLUORESCENCE; STATE-TO-STATE; CROSS-SECTIONS; TESICO TECHNIQUE; PROTON-TRANSFER; COLLISIONS; N-2+; DISTRIBUTIONS; EXCITATION AB The charge transfer reaction of N-2(+)(v = 0-4) + Kr-->N-2+Kr+ is studied at thermal energy as a function of vibrational excitation in the reactant ion, The selected-ion flow tube technique coupled with laser-induced fluorescence detection is used to measure the vibrationally state specific rate constants. A dramatic vibrational enhancement is observed; measured rate constants are 1.0 (+/-0.6)x10(-12), 2.8 (+/-0.3)x10(-12), 2.1 (+/-0.2)x10(-11), 5.1 (+/-0.2)x10(-11), and 8.3 (+/-0.4)x10(-11) cm(3) molecule(-1) s(-1) for v=0, 1, 2, 3 and 4, respectively. Mass spectrometric kinetics experiments are also performed to confirm that vibrational relaxation, N-2(+)(v)+Kr-->N-2(+)(v' < v) + Kr, is a negligible process. The charge transfer for v = 0 is extremely slow in spite of the large exothermicity (e.g., 0.915 eV for the production of N-2(v' = 0)+Kr+(P-2(1/2)) states), yet the reaction is enhanced when the apparent energy mismatch is greater for the vibrationally excited reactant. A simple model is proposed to explain the experimental results at thermal energies (much less than 1 eV). The model assumes that only the most energy-resonant exothermic transitions, N-2(+)(v) + Kr-->N-2(v + 3)+Kr+(P-2(1/2)), occur within the duration of the ion-molecule collision complex and that the charge transfer takes place with probabilities governed by the corresponding Franck-Condon factors. However, the Franck-Condon factors are modified by a trial displacement of 0.02 Angstrom to account for the changes in vibrational wave functions of N-2(+) and N-2 during a close approach of the (N-2-Kr)(+) pair; this method gives an excellent description of the experimental results. (C) 1996 American Institute of Physics. C1 NATL INST STAND & TECHNOL,JILA,BOULDER,CO 80309. NATL INST STAND & TECHNOL,QUANTUM PHYS DIV,BOULDER,CO 80309. KANSAS STATE UNIV,DEPT PHYS,MANHATTAN,KS 66506. UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. UNIV COLORADO,DEPT PHYS,BOULDER,CO 80309. RI Lin, c d/D-7312-2012; de Gouw, Joost/A-9675-2008 OI Lin, c d/0000-0003-4847-8938; de Gouw, Joost/0000-0002-0385-1826 NR 60 TC 14 Z9 14 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD OCT 1 PY 1996 VL 105 IS 13 BP 5455 EP 5466 DI 10.1063/1.472386 PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VL469 UT WOS:A1996VL46900019 ER PT J AU Tewari, YB Goldberg, RN AF Tewari, YB Goldberg, RN TI Thermodynamics of reactions catalyzed by L-iditol 2-dehydrogenase: The xylose assimilation pathway SO JOURNAL OF CHEMICAL THERMODYNAMICS LA English DT Article ID ADENOSINE 5'-TRIPHOSPHATE; SORBITOL DEHYDROGENASE; PACHYSOLEN-TANNOPHILUS; XYLITOL-DEHYDROGENASE; PURIFICATION; EQUILIBRIUM AB Apparent equilibrium constants and calorimetric enthalpies of reaction have been measured for the following enzyme catalyzed (L-iditol 2-dehydrogenase) biochemical reactions in phosphate buffer at pHs near 7.5 and at the temperature 298.15 K D-sorbitol(aq) + NAD(ox)(aq) = D-fructose(aq) + NAD(red)(aq), L-iditol(aq) + NAD(ox)(aq) = L-sorbose(aq) + NAD(red)(aq), xylitol(aq) + NAD(ox)(aq) = D-xylulose(aq)+ NAD(red)(aq). Here, NAD(ox) is beta-nicotinamide-adenine dinucleotide (oxidized form) and NAD(red) is beta-nicotinamide-adenine dinucleotide (reduced form). The results are used to calculate equilibrium constants and standard molar enthalpies, entropies, and Gibbs free energies for reference reactions involving specific species. Standard formation properties and standard transformed formation properties of the biochemical reactants are also calculated. The thermodynamics of the xylose assimilation pathway is summarized. (C) 1996 Academic Press Limited RP Tewari, YB (reprint author), NATL INST STAND & TECHNOL,DIV BIOTECHNOL,GAITHERSBURG,MD 20899, USA. NR 35 TC 4 Z9 4 U1 2 U2 4 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON, ENGLAND NW1 7DX SN 0021-9614 J9 J CHEM THERMODYN JI J. Chem. Thermodyn. PD OCT PY 1996 VL 28 IS 10 BP 1127 EP 1144 DI 10.1006/jcht.1996.0099 PG 18 WC Thermodynamics; Chemistry, Physical SC Thermodynamics; Chemistry GA VN944 UT WOS:A1996VN94400009 ER PT J AU Esbensen, SK McPhaden, MJ AF Esbensen, SK McPhaden, MJ TI Enhancement of tropical ocean evaporation and sensible heat flux by atmospheric mesoscale systems SO JOURNAL OF CLIMATE LA English DT Article ID WESTERN PACIFIC-OCEAN; NORTH-ATLANTIC; PARAMETERIZATION; PRECIPITATION; ARRAY AB The enhancement of monthly averaged evaporation by atmospheric mesoscale systems is estimated from longterm hourly observations of surface meteorological data from the Tropical Ocean Global Atmosphere (TOGA) Tropical Atmosphere Ocean (TAO) buoy moorings over the equatorial Pacific Ocean and a bulk aerodynamic flux algorithm developed as a result of the TOGA Coupled Ocean-Atmosphere Response Experiment (COARE). It is shown that mesoscale enhancement is due primarily to the lack of wind steadiness on subsynoptic timescales and is associated with periods of significant precipitation. The magnitude of the mesoscale enhancement of monthly averaged sea surface evaporation is found to be similar to 10% or less of the total. During occasional periods with weak and variable winds over the western Pacific warm pool and the other major precipitation zones in the equatorial Pacific, the mesoscale enhancement of monthly averaged evaporation can reach 30% of the total evaporation. A similar result is obtained for mesoscale enhancement of diffusive air-sea sensible heat transfer using data from TOGA TAO moorings. However, a comparison of results from the colocated TAO and Improved METeorological measurements (IMET) moorings during TOGA COARE, and results previously reported from a pre-COARE cruise in the western Pacific warm pool region, indicate that processes in addition to mesoscale wind variability may be important contributors to the mesoscale enhancement of the sensible hear Aux. It is suggested that the most important effects of atmospheric mesoscale systems on tropical ocean evaporation and sensible heat flux are represented in existing climatologies. C1 NOAA,PACIFIC MARINE ENVIRONM LAB,SEATTLE,WA 98115. RP Esbensen, SK (reprint author), OREGON STATE UNIV,COLL OCEAN & ATMOSPHER SCI,CORVALLIS,OR 97331, USA. RI McPhaden, Michael/D-9799-2016 NR 34 TC 50 Z9 54 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD OCT PY 1996 VL 9 IS 10 BP 2307 EP 2325 DI 10.1175/1520-0442(1996)009<2307:EOTOEA>2.0.CO;2 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VQ571 UT WOS:A1996VQ57100003 ER PT J AU Delworth, TL AF Delworth, TL TI North Atlantic interannual variability in a coupled ocean-atmosphere model SO JOURNAL OF CLIMATE LA English DT Article ID SEA-SURFACE TEMPERATURE; EXTRATROPICAL SST ANOMALIES; GENERAL-CIRCULATION MODEL; HEAT-FLUX ANOMALIES; INTERDECADAL VARIATIONS; TRANSIENT RESPONSES; GRADUAL CHANGES; HEIGHT FIELD; WINTER; PATTERNS AB The primary mode of sea surface temperature variability in the North Atlantic or interannual timescales during winter is examined in a coupled ocean-atmosphere model. The model, developed at the Geophysical Fluid Dynamics Laboratory, is global in domain with realistic geography and a seasonal cycle of insolation. Analyses performed on a 1000-year integration of this model show that this mode is characterized by zonal bands of SST anomalies in the North Atlantic and bears a district resemblance to observational results. The largest anomalies in the model are to the southeast of Newfoundland. The model SST variations appear to be related to a north-south dipole in the atmospheric 500-mb geopotential height field, which resembles the North Atlantic oscillation and the Western Atlantic pattern. Analyses are presented that show that this mode of SST variability is primarily driven by perturbations to the surface heat fluxes, which are largely governed by atmospheric variability. Changes in model ocean circulation also contribute to this mode of variability but appear to be of secondary importance. Additional integrations are analyzed to examine the above conclusion. The same atmospheric model used in the above integration was coupled to a 50-m slab ocean and integrated for 500 years. The primary mode of SST variability in this model, in which there were no effects of ocean dynamics, resembles that primary mode from the coupled model, strengthening the conclusion that the surface fluxes are the primary mechanism generating this oceanic variability. One notable difference between the two models is related to the presence of deep vertical mixing at high latitudes in the model with a fully dynamic ocean. An additional 500-year integration of the atmospheric model with a prescribed seasonal cycle of SSTs lend further support to this conclusion, as do additional diagnostic calculations in which a 50-m slab ocean was forced by the time series of surface fluxes from both the prescribed SST and fully coupled model. RP Delworth, TL (reprint author), NOAA,GEOPHYS FLUID DYNAM LAB,POB 308,PRINCETON,NJ 08542, USA. RI Delworth, Thomas/C-5191-2014 NR 45 TC 91 Z9 99 U1 0 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD OCT PY 1996 VL 9 IS 10 BP 2356 EP 2375 DI 10.1175/1520-0442(1996)009<2356:NAIVIA>2.0.CO;2 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VQ571 UT WOS:A1996VQ57100006 ER PT J AU Semazzi, FHM Burns, B Lin, NH Schemm, JK AF Semazzi, FHM Burns, B Lin, NH Schemm, JK TI A GCM study of the teleconnections between the continental climate of Africa and global sea surface temperature anomalies SO JOURNAL OF CLIMATE LA English DT Article ID SUB-SAHARAN RAINFALL; VARIABILITY; SAHEL; COHERENCE; DROUGHT; REGION; OCEAN AB In this case study the role of global SST anomaly forcing in promoting the extreme climatic conditions that prevailed in Africa during the years of 1950 and 1973 is examined, In 1950 abundant rainfall was observed over tropical Africa, particularly over the Sahel and Southern Africa, ay contrast, in 1973, this rainfall anomaly pattern was characterized by the opposite phase, with most of the continent experiencing severe droughts. The primary research vehicle in this investigation is the standard version of the NCAR CCMl GCM with horizontal resolution of rhombodial spectral truncation at wavenumber 15 (R15),Two separate 10-yr simulations based on the 1950 and 1973 observed sea surface temperature (SST) have been performed. The empirical orthogonal functions method is employed to isolate the annual cycle harmonics in the data and also to remove statistical noise, The filtered seasonal rainfall fields for the model and the observations are compared to investigate the response of the African continental climate to the 1950 and 1973 SST climatologies, CCMl successfully simulates the primary features of the seasonal mean climate conditions and anomalies over the Sahel and Southern Africa, The authors attribute this to the ability of the model to simulate the annual harmonic oscillation realistically. Over equatorial Africa, where the semiannual oscillation is:observed to be relatively more important than it is at the higher latitudes of the continent, the model simulation is not as successful, This occurs because of the deficient simulation of the semiannual harmonic oscillation by the model, A weaker annual cycle comprising: the annual mean (nonoscillating component) and the annual harmonic oscillation in tl-ie 1973 Nn relative to the 1950 experiment provides a viable explanation for the synchronous climatic anomaly conditions that prevailed in northern and southern Africa cl;ring these two years. Investigation of the relative role of the GCM's internal variability and the SST externally forced variability during the rainy season over tropical Africa yields valuable insight into the reasons for the observed anomalous climatic behavior. Over the Sahel and Southern Africa, where the annual harmonic oscillation is relatively large, externally forced SST variability dominates over internal variability in explaining the drier conditions in 1973 relative to 1950. C1 N CAROLINA STATE UNIV, DEPT MATH, RALEIGH, NC 27695 USA. NATL CENT UNIV, DEPT ATMOSPHER SCI, CHUNGLI, TAIWAN. NOAA, NWS, NMC, CLIMATE ANAL CTR, CAMP SPRINGS, MD USA. RP Semazzi, FHM (reprint author), N CAROLINA STATE UNIV, DEPT MARINE EARTH & ATMOSPHER SCI, BOX 8208, RALEIGH, NC 27695 USA. NR 32 TC 31 Z9 32 U1 0 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD OCT PY 1996 VL 9 IS 10 BP 2480 EP 2497 DI 10.1175/1520-0442(1996)009<2480:AGSOTT>2.0.CO;2 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VQ571 UT WOS:A1996VQ57100013 ER PT J AU Lanzante, JR AF Lanzante, JR TI Lag relationships involving tropical sea surface temperatures SO JOURNAL OF CLIMATE LA English DT Article ID SOUTHERN OSCILLATION; EL-NINO; VARIABILITY; PACIFIC; OCEAN; CIRCULATION; ATLANTIC; ANOMALIES; SYSTEM; SCALES AB A long historical record (similar to 100 years) of monthly sea surface temperature anomalies from the Comprehensive Ocean-Atmosphere Data Set was used to examine the lag relationships between different locations in the global Tropics. Application of complex principal component (CPS) analysis revealed that the leading mode captures ENSO-related quasi-cyclical warming and cooling in the tropical Pacific Ocean. The cominant features of this mode indicated that SST anomalies in the eastern Pacific lead those of the central Pacific. However, a somewhat weaker aspect of this mode also indicates that SST anomalies in the tropical Indian and western tropical North Atlantic Oceans vary roughly in concert with each other but lag behind those in the central and eastern Pacific. The stability of these lag relationships is indicated by the fact that the leading mode is quite similar in three different 30-year time periods. In order to further examine these relationships some simple indexes were formed as the average over several grid points in each of the four key areas suggested by the CPC analyses. Several different types of analyses including lag correlation, checking the correspondence between extrema, and visual examination of time series plots were used to confirm the relationships implied by the CPC spatial patterns. By aggregating the lag correlations over the three 30-year time periods and preforming a Monte Carlo simulation the relationships were found to be statistically significant at the 1% level. Reasonable agreement in the pattern of lag correlations was found using a different SST dataset. Without aggregation of the lag correlations (i.e. considering each 30-year period separately) the areas in the Pacific and Indian were consistently well related, but those involving the North Atlantic were more variable. The weaker correlations involving the Atlantic Ocean underscore the more tenuous nature of this remote relationship. While major ENSO-related swings in tropical Pacific SST are often followed by like variations in a portion of the Atlantic, there are times when there is either no obvious association or one of opposite sign. It may be that while ENSO variability tends to have an impact in the Atlantic, more localized factors can override this tendency. This may explain some of the contradictory statements found in the literature regarding such remote associations. In comparing the findings of this project with some studies that utilize very recent data (since about 1982) some discrepancies were noted. In particular, some studies have reported evidence of 1) an inverse relationship between SST anomalies in the tropical. Pacific and those in the eastern tropical South Atlantic and 2) the appearance of ENSO-related SST anomalies in the central tropical Pacific prior to those in the eastern tropical Pacific. From a historical perspective both of these characteristics are unusual. Thus, the recent time period may merit special attention. However, it is important to stress the caution should be exercised in generalizing findings based only on this recent time period. RP Lanzante, JR (reprint author), PRINCETON UNIV,NOAA,GEOPHYS FLUID DYNAM LAB,US DEPT COMMERCE,POB 308,PRINCETON,NJ 08542, USA. NR 21 TC 62 Z9 65 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD OCT PY 1996 VL 9 IS 10 BP 2568 EP 2578 DI 10.1175/1520-0442(1996)009<2568:LRITSS>2.0.CO;2 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VQ571 UT WOS:A1996VQ57100018 ER PT J AU Barnston, AG He, YX AF Barnston, AG He, YX TI Skill of canonical correlation analysis forecasts of 3-month mean surface climate in Hawaii and Alaska SO JOURNAL OF CLIMATE LA English DT Article ID NORTHERN HEMISPHERE WINTER; NINO-SOUTHERN OSCILLATION; GEOPOTENTIAL HEIGHT FIELD; EL-NINO; CIRCULATION PATTERNS; STATISTICAL-MODELS; UNITED-STATES; TELECONNECTIONS; PRECIPITATION; RAINFALL AB Statistical short-term climate predictive skills and their sources for 3-month mean local surface climate (temperature and precipitation) in Hawaii and Alaska have been explored at lead times of up to one year using a canonical correlation analysis (CCA). Four consecutive 3-month predictor periods are followed by a variable lead time and then a single 3-month predictand period. Predictor fields are quasi-global sea surface temperature, Northern Hemisphere 700-mb height, and prior values of the predictand field itself. Forecast skill is estimated using cross-validation. Shea-term global climate fluctuations such as the Fl Nino-Southern Oscillation (ENSO) phenomenon are found to play an important role in the climate variability in Hawaii and the southern half of Alaska. During the late winter and spring of mature warm (cold) ENSO events, Hawaii tends to be anomalously warm and dry (wet and cool), while southern Alaska tends to be warm (cold). Hawaii's responses occur more strongly the year after a mature ENSO event rather than the year of the event, even if the opposite phase of ENSO has already begun. Persistence is the best seasonal temperature prediction for Hawaii at short leads. Winter and spring temperature (precipitation) can be predicted up to one year (a few months) in advance with modest but usable skill for Hawaii, where temperature forecasts are generally more skillful. Southern Alaska has temperature prediction possibilities up to 7-10 months in advance. While Alaskan seasonal precipitation prediction is poor on the large spatial scale, forecasts on terrain-dependent local scales may be more fruitful using methods other than CCA. RP Barnston, AG (reprint author), NOAA,NWS,NATL CTR ENVIRONM PREDICT,CLIMATE PREDICT CTR,W-NP51 WWB ROOM 604,WASHINGTON,DC 20233, USA. NR 34 TC 20 Z9 25 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD OCT PY 1996 VL 9 IS 10 BP 2579 EP 2605 DI 10.1175/1520-0442(1996)009<2579:SOCCAF>2.0.CO;2 PG 27 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VQ571 UT WOS:A1996VQ57100019 ER PT J AU Ting, MF Hoerling, MP Xu, TY Kumar, A AF Ting, MF Hoerling, MP Xu, TY Kumar, A TI Northern hemisphere teleconnection patterns during extreme phases of the zonal-mean circulation SO JOURNAL OF CLIMATE LA English DT Article ID SEA-LEVEL PRESSURE; EL-NINO; SOUTHERN OSCILLATION; ATLANTIC OSCILLATION; GEOPOTENTIAL HEIGHT; STATIONARY WAVES; VARIABILITY; ANOMALIES; PACIFIC; FLOW AB Regional climate anomalies associated with year-to-year changes in the tropospheric zonal-mean zonal wind ((u) over bar) are examined. This study focuses on the wintertime Northern Hemisphere extratropics and compares seasonal mean anomalies associated with (u) over bar to those associated with the El Nino-Southern Oscillation during the 1947-94 period. Dynamical model experiments indicate that a single zonal index, characterized by out-of-phase (u) over bar anomalies at 35 degrees and 55 degrees N, is of primary importance for zonal flow/stationary wave interactions in the Northern Hemisphere extratropics. Such fluctuations in the zonal-mean zonal flow are shown to occur independently to tropical SST variability, consistent with earlier studies. Dynamical model experiments and regression analyses of the historical data indicate that such a zonal index explains a significant fraction of the wintertime stationary wave variability in several regions. The principal centers of action reside within wave trains over the North Pacific-North American region and the North Atlantic-Eurasian region where locally 30%-40% of the eddy height variability is explained by the zonal index. Only over the North Pacific does the stationary wave signal related to ENSO appreciably exceed that associate with the zonal index. The surface climate associated with the zonal index is described by a wavenumber 1 pattern, which has out-of-phase temperature anomalies between Eurasia and North America and amplitudes considerably larger than those experienced during ENSO. The analysis offers a physical basis for understanding extratropical seasonal climate anomalies as a simple linear combination of teleconnection patterns associated with (u) over bar states and ENSO states. The utility of such an approach is illustrated for several cases of hitherto unexplained observed extreme climate anomalies during northern winter. It is also shown that a significant fraction of the interannual variability in some regions cannot be explained by either a zonal index or ENSO. A further important feature of the zonal index in the 1947-94 period is the recurrence of anomalies over multiyear periods. Such behavior has important implications for decadal climate variations, examples of which are given for secular changes after 1976. C1 UNIV COLORADO,CIRES,BOULDER,CO 80309. NOAA,NCEP,WASHINGTON,DC. RP Ting, MF (reprint author), UNIV ILLINOIS,DEPT ATMOSPHER SCI,105 S GREGORY AVE,URBANA,IL 61801, USA. NR 35 TC 70 Z9 80 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD OCT PY 1996 VL 9 IS 10 BP 2614 EP 2633 DI 10.1175/1520-0442(1996)009<2614:NHTPDE>2.0.CO;2 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VQ571 UT WOS:A1996VQ57100021 ER PT J AU PenaMora, F Sriram, D Logcher, R AF PenaMora, F Sriram, D Logcher, R TI Design rationale for computer-supported conflict mitigation - Closure SO JOURNAL OF COMPUTING IN CIVIL ENGINEERING LA English DT Editorial Material C1 NATL INST STAND & TECHNOL,MFG SYST INTEGRAT DIV,GAITHERSBURG,MD 20899. RP PenaMora, F (reprint author), MIT,DEPT CIVIL & ENVIRONM ENGN,INTELLIGENT ENGN SYST LAB,CAMBRIDGE,MA 02139, USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU ASCE-AMER SOC CIVIL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 SN 0887-3801 J9 J COMPUT CIVIL ENG JI J. Comput. Civil. Eng. PD OCT PY 1996 VL 10 IS 4 BP 328 EP 329 PG 2 WC Computer Science, Interdisciplinary Applications; Engineering, Civil SC Computer Science; Engineering GA VH866 UT WOS:A1996VH86600012 ER PT J AU Lockwood, M Cowley, SWH Onsager, TG AF Lockwood, M Cowley, SWH Onsager, TG TI Ion acceleration at both the interior and exterior Alfven waves associated with the magnetopause reconnection site: Signatures in cusp precipitation SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID LATITUDE BOUNDARY-LAYER; LOW-ALTITUDE SATELLITE; GROUND-BASED OBSERVATIONS; DAYSIDE MAGNETOPAUSE; FIELD LINES; FLOW EVENTS; MAGNETOSPHERE; CONVECTION; PLASMA; IDENTIFICATION AB We present evidence for the acceleration of magnetospheric ions by reflection off two Alfven waves, launched by the reconnection site into the inflow regions on both sides of the reconnecting magnetopause. The ''exterior'' wave stands in the inflow from the magnetosheath and is the magnetopause, in the sense that the majority of the field rotation occurs there. The other, ''interior'' wave stands in the inflow region on the magnetospheric side of the boundary. The population reflected by the interior wave is the more highly energized of the two and appears at low altitudes on open field lines, immediately equatorward of the cusp precipitation. In addition, we identify the population of magnetosheath ions transmitted across the exterior Alfven wave, as well as a population of magnetospheric ions which are accelerated, after transmission through the interior wave, by reflection off the exterior wave. The ion populations near the X line are modeled and, with allowance for time-of-flight effects, are also derived from observations in the dayside auroral ionosphere. Agreement between observed and theoretical spectra is very good and the theory also explains the observed total fluxes and average energies of the precipitations poleward of the open/closed field line boundary. The results offer a physical interpretation of all the various classifications of precipitation into the dayside ionosphere (central plasma sheet, dayside boundary plasma sheet, void, low-latitude boundary layer, cusp, and mantle) and allow the conditions in both the magnetosphere and the magnetosheath adjacent to the X line to be studied. C1 UNIV LEICESTER,DEPT PHYS & ASTRON,LEICESTER LE1 7RH,LEICS,ENGLAND. NOAA,SPACE ENVIRONM CTR,BOULDER,CO 80303. RP Lockwood, M (reprint author), RUTHERFORD APPLETON LAB,DIDCOT OX11 0QX,OXON,ENGLAND. RI Lockwood, Mike/G-1030-2011 OI Lockwood, Mike/0000-0002-7397-2172 NR 37 TC 29 Z9 30 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD OCT 1 PY 1996 VL 101 IS A10 BP 21501 EP 21513 DI 10.1029/96JA01948 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VK704 UT WOS:A1996VK70400006 ER PT J AU Vandas, M Fischer, S Geranios, A Dryer, M Smith, Z Detman, T AF Vandas, M Fischer, S Geranios, A Dryer, M Smith, Z Detman, T TI Magnetic traps in the interplanetary medium associated with magnetic clouds SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID FIELD STRUCTURE; EVENTS; MAGNETOSPHERE; HELIOSPHERE; PARTICLES; LOOPS AB MHD simulations of the propagation of magnetic clouds in the interplanetary medium show that interplanetary magnetic field (IMF) lines, draping around the cloud, are often bent in a complicated way. The magnetic field along these field Lines (even on nonbent sections) is not smoothly decreasing with increasing distance from the Sun but usually exhibits several extreme values (minima and maxima). Depressions in the IMF strength may trap energetic particles with suitable energies and pitch angles. These particles may remain trapped (in the expanding region) until the IMF configuration changes. Possible locations of magnetic traps are shown in this paper. C1 NOAA, R E SE, SPACE ENVIRONM CTR, BOULDER, CO 80303 USA. UNIV ATHENS, DEPT PHYS, NUCL & PARTICLE PHYS SECT, GR-15771 ATHENS, GREECE. UNIV COLORADO, COOPERAT INST RES ENVIRONM SCI, BOULDER, CO 80309 USA. RP Vandas, M (reprint author), ACAD SCI CZECH REPUBL, INST ASTRON, BOCNI II 1401, PRAGUE 14131 4, CZECH REPUBLIC. RI Vandas, Marek/G-9054-2014; xue, yansheng/A-9712-2012 NR 30 TC 11 Z9 11 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD OCT 1 PY 1996 VL 101 IS A10 BP 21589 EP 21596 DI 10.1029/96JA01640 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VK704 UT WOS:A1996VK70400014 ER PT J AU Jin, M Fread, DL AF Jin, M Fread, DL TI Channel routing with flow losses SO JOURNAL OF HYDRAULIC ENGINEERING-ASCE LA English DT Article AB A technique is developed and implemented within the NWS FLDWAV model to account for the effect of flow-volume losses in one-dimensional (1D) open-channel unsteady flow modeling. A functional form for the loss-induced lateral outflow is derived based on a specified total-volume distribution along the reach in which the loss occurs. The flow-loss-enhanced FLDWAV model is capable of modeling unsteady flow with any specified amount of flow loss between any two cross sections along the routing reach. C1 NOAA,NATL WEATHER SERV,OFC HYDRO,SILVER SPRING,MD 20910. RP Jin, M (reprint author), NOAA,NATL WEATHER SERV,HYDROL RES LAB,1325 EAST WEST HIGHWAY,SILVER SPRING,MD 20910, USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU ASCE-AMER SOC CIVIL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 SN 0733-9429 J9 J HYDRAUL ENG-ASCE JI J. Hydraul. Eng.-ASCE PD OCT PY 1996 VL 122 IS 10 BP 580 EP 582 DI 10.1061/(ASCE)0733-9429(1996)122:10(580) PG 3 WC Engineering, Civil; Engineering, Mechanical; Water Resources SC Engineering; Water Resources GA VJ026 UT WOS:A1996VJ02600007 ER PT J AU Lovas, FJ Lugez, CL AF Lovas, FJ Lugez, CL TI The microwave spectrum and structure of CH2O-H2O SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID WATER FORMALDEHYDE COMPLEX; HYDROGEN-BONDED COMPLEXES; BEAM ELECTRIC RESONANCE; ROTATIONAL SPECTRUM; CARBONYL ADDITION; INFRARED-SPECTRUM; DIPOLE-MOMENT; DIMER; TRANSITION; SOLVATION AB The microwave spectrum of the formaldehyde-water complex (CH2O-H2O) has been studied with a pulsed-beam Fourier transform Fabry-Perot cavity spectrometer. Both a-type and b-type transitions were observed for each of the isotopic species studied. To provide additional structural information, the spectra of H2O, HDO, and D2O substituents combined with H2CO and D2CO were assigned. Measurement of the dipole moment components yielded the values mu(a) = 3.379(13) X 10(-30) C . m (mu(a) = 1.043(4) D) and mu(b) = 2.54(20) X 10(-30) C . m (mu(b) = 0.76(6) D) and indicated that the dipole moment vectors are anti-aligned. The molecular structure derived from the moments of inertia has a center of mass separation of 3.00(3) Angstrom with the C-2v symmetry axes of the monomers oriented at 19.3 degrees from parallel with the dipole moments opposed. The complex is quite strongly bound with a harmonic pseudodiatomic stretching force constant, k(s) = 8.93 N/m, and hydrogen bond lengths of approximately 2.68 Angstrom between the water oxygen atom and a CH2 hydrogen atom, and 2.03 Angstrom between a water hydrogen atom and the oxygen atom of H2CO. Expanded uncertainties (coverage factor k = 2, i.e., two standard deviations) are shown in parentheses for each experimental value reported above. (C) 1996 Academic Press, Inc. RP Lovas, FJ (reprint author), NATL INST STAND & TECHNOL,DIV OPT TECHNOL,GAITHERSBURG,MD 20899, USA. NR 38 TC 18 Z9 18 U1 1 U2 6 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD OCT PY 1996 VL 179 IS 2 BP 320 EP 323 DI 10.1006/jmsp.1996.0210 PG 4 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA VG709 UT WOS:A1996VG70900015 ER PT J AU Mellor, GL Wang, XH AF Mellor, GL Wang, XH TI Pressure compensation and the bottom boundary layer SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID CIRCULATION; OCEAN; MODEL; TRANSPORT; SLOPE; FLOW AB It is an observed characteristic of oceans that velocities and horizontal pressure gradients are larger near the ocean surface than they are in deeper water. This is conventionally labeled ''pressure compensation'' whereby baroclinic structure, comprising sloping isopycnal surfaces, is adjusted so that surface pressure gradients are reduced in deeper water. In this paper, a two-dimensional Row in a channel is numerically modeled to demonstrate the baroclinic adjustment process and its relationship to the bottom boundary layer. A simple analytical model is also developed and defines the timescale of die adjustment process. C1 UNIV COLL,AUSTRALIAN DEF FORCE ACAD,DEPT GEOG & OCEANOG,CANBERRA,ACT,AUSTRALIA. RP Mellor, GL (reprint author), PRINCETON UNIV,PROGRAM ATMOSPHER & OCEAN SCI,POB CN710,SAYRE HALL,PRINCETON,NJ 08544, USA. NR 18 TC 21 Z9 21 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0022-3670 J9 J PHYS OCEANOGR JI J. Phys. Oceanogr. PD OCT PY 1996 VL 26 IS 10 BP 2214 EP 2222 DI 10.1175/1520-0485(1996)026<2214:PCATBB>2.0.CO;2 PG 9 WC Oceanography SC Oceanography GA VP255 UT WOS:A1996VP25500014 ER PT J AU Robey, SW Hudson, LT Henrich, VE Eylem, C Eichhorn, B AF Robey, SW Hudson, LT Henrich, VE Eylem, C Eichhorn, B TI Resonant photoelectron spectroscopy studies of BaTiO3 and related mixed oxides SO JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS LA English DT Article; Proceedings Paper CT 3rd Williamsburg Workshop on Fundamental Experiments on Ferroelectrics CY FEB 05-08, 1995 CL WILLIAMSBURG, VA SP USN, Office Naval Res DE oxides; photoelectron spectroscopy; electronic structure; ferroelectricity ID ELECTRONIC-STRUCTURE; PHOTOEMISSION; STATES; FERROELECTRICITY; SURFACES; ND AB Synchrotron radiation-based ultraviolet photoelectron spectroscopy (UPS was used to investigate the electronic structure of BaTiO3 and related mixed oxides. In particular, resonant photoelectron effects at the Ti 3p threshold provide a picture of the contribution of the Ti 3d states to the predominantly O 2p valence band, and thus produce information on Ti 3d-O 2p hybridization. This is used to determine the Ti-O hybridization in BaTiO3 and comparisons are made to the Ti partial density of states obtained from first principles calculations of the band structure of BaTiO3. We have also investigated the effects of substitution of Nd for Sr in SrTiO3 to form the mixed oxide Nd1-xSrxTiO3. These studies illuminate the effects of changing crystal structure and bandfilling on Ti 3d-O 2p hybridization. C1 YALE UNIV,DEPT APPL PHYS,NEW HAVEN,CT 06520. UNIV MARYLAND,DEPT CHEM & BIOCHEM,CTR SUPERCONDUCT RES,COLLEGE PK,MD 20742. RP Robey, SW (reprint author), NIST,GAITHERSBURG,MD 20899, USA. NR 21 TC 8 Z9 8 U1 0 U2 13 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0022-3697 J9 J PHYS CHEM SOLIDS JI J. Phys. Chem. Solids PD OCT PY 1996 VL 57 IS 10 BP 1385 EP 1391 DI 10.1016/0022-3697(96)00002-9 PG 7 WC Chemistry, Multidisciplinary; Physics, Condensed Matter SC Chemistry; Physics GA VK053 UT WOS:A1996VK05300003 ER PT J AU Wang, CM Lam, CT AF Wang, CM Lam, CT TI Confidence limits for proportion of conformance SO JOURNAL OF QUALITY TECHNOLOGY LA English DT Article ID CAPABILITY INDEXES AB This paper presents two approximate methods for constructing lower confidence limits for proportion of conformance. Proportion of conformance is defined as the proportion of products with quality characteristic inside the specification limits. The performance of each method is assessed by simulation. Numerical examples are also given to illustrate the procedures. C1 UNIV MICHIGAN,DEPT IND & OPERAT ENGN,ANN ARBOR,MI 48109. RP Wang, CM (reprint author), NATL INST STAND & TECHNOL,DIV STAT ENGN,325 BROADWAY,BOULDER,CO 80303, USA. NR 17 TC 10 Z9 10 U1 0 U2 1 PU AMER SOC QUALITY CONTROL-ASQC PI MILWAUKEE PA ASQC MEMBERSHIP MANAGER 611 E. WISCONSIN AVENUE, MILWAUKEE, WI 53202 SN 0022-4065 J9 J QUAL TECHNOL JI J. Qual. Technol. PD OCT PY 1996 VL 28 IS 4 BP 439 EP 445 PG 7 WC Engineering, Industrial; Operations Research & Management Science; Statistics & Probability SC Engineering; Operations Research & Management Science; Mathematics GA VR650 UT WOS:A1996VR65000005 ER PT J AU Zelkowitz, MV AF Zelkowitz, MV TI Modeling software engineering environment capabilities SO JOURNAL OF SYSTEMS AND SOFTWARE LA English DT Article AB There is considerable interest today in designing open systems that permit tools to be moved freely among various environments on different hardware platforms. To develop such systems, terms such as open systems, features for open systems such as interoperability, and integration must all be precisely defined. We present a model that is an extension of a service-based reference model for development environments that can be used to formally define these and other related concepts. C1 NATL INST STAND & TECHNOL,COMP SYST LAB,GAITHERSBURG,MD 20899. RP Zelkowitz, MV (reprint author), UNIV MARYLAND,INST ADV COMP STUDIES,DEPT COMP SCI,COLLEGE PK,MD 20742, USA. NR 14 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 0164-1212 J9 J SYST SOFTWARE JI J. Syst. Softw. PD OCT PY 1996 VL 35 IS 1 BP 3 EP 14 DI 10.1016/0164-1212(95)00082-8 PG 12 WC Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA VH075 UT WOS:A1996VH07500002 ER PT J AU Nechvatal, J AF Nechvatal, J TI A public-key-based key escrow system SO JOURNAL OF SYSTEMS AND SOFTWARE LA English DT Article AB A key escrow system allows devices such as telephones or computers to communicate securely, while permitting a monitor such as a law enforcement agency to access encrypted communications under prescribed conditions. The U.S. government has created an escrow system using secret-key cryptography and classified algorithms, implementable in hardware only. We describe an alternative escrow system that uses public-key cryptography and nonclassified algorithms, implementable in hardware or software. The new system should give users (and perhaps governments) more confidence, be more exportable, and permit a fully automated escrow/retrieval system. RP Nechvatal, J (reprint author), NATL INST STAND & TECHNOL,BLDG 225,ROOM A-216,GAITHERSBURG,MD 20899, USA. NR 9 TC 6 Z9 15 U1 1 U2 2 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 0164-1212 J9 J SYST SOFTWARE JI J. Syst. Softw. PD OCT PY 1996 VL 35 IS 1 BP 73 EP 83 DI 10.1016/0164-1212(95)00087-9 PG 11 WC Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA VH075 UT WOS:A1996VH07500008 ER PT J AU Ramakrishnan, V Pradip Malghan, SG AF Ramakrishnan, V Pradip Malghan, SG TI Yield stress of alumina-zirconia suspensions SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID RHEOLOGY AB The yield stress of concentrated suspensions of alumina, zirconia, and mixed alumina-zirconia powders was measured by the vane technique as a function of a,lids loading, relative amounts of alumina and zirconia, and pH. At the isoelectric point (IEP), the yield stress varied as the fourth power of the solids loading, The relative ratio of alumina and zirconia particles was important in determining the yield stress of the suspension at the IEP, The yield stress of single and mixed suspensions showed a marked variation with pH. The maximum value occurred at or near the IEP of the suspension, The effect of electrical double-layer forces on the yield stress can be described on the basis of the Derjaguin-Landau-Vermey-Overbeek (DLVO) theory, A normalized yield stress-that is, the ratio of the yield stress at a given pH to the yield stress at the IEP predicted by this model-showed good correlation with experimental data. C1 NIST,GAITHERSBURG,MD 20899. RP Ramakrishnan, V (reprint author), TATA RES DEV & DESIGN CTR,PUNE 411001,MAHARASHTRA,INDIA. NR 16 TC 30 Z9 30 U1 0 U2 0 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD OCT PY 1996 VL 79 IS 10 BP 2567 EP 2576 PG 10 WC Materials Science, Ceramics SC Materials Science GA VP021 UT WOS:A1996VP02100008 ER PT J AU FischerCripps, AC Lawn, BR AF FischerCripps, AC Lawn, BR TI Stress analysis of contact deformation in quasi-plastic ceramics SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID HETEROGENEOUS GRAIN-STRUCTURE; PARTIALLY-STABILIZED ZIRCONIA; HERTZIAN CONTACTS; SILICON-CARBIDE; POLYCRYSTALLINE CERAMICS; DAMAGE ACCUMULATION; CRACK-RESISTANCE; TOUGHNESS CURVES; CYCLIC FATIGUE; INDENTATION AB A stress analysis is made of Hertzian contact de formation in relatively tough ceramics with heterogeneous microstructures, where the response is essentially quasi-plastic rather than ideally elastic-brittle, Contact data for two such heterogeneous ceramics, a micaceous glass-ceramic with modest hardness and a silicon nitride with high hardness, are presented as illustrative cases, Data from a soft steel serve as a comparative baseline, Two distinctive aspects of the deformation response are explored: indentation stress-strain nonlinearity; and size and shape of the damage zone, For the harder ceramics, the stress-strain nonlinearity is less pronounced, and the quasi-plastic zone is more tightly confined beneath the contact, than in traditional ductile metals, As in metals, the deformation process in the ceramic structures is essentially shear driven, but has its origin in microstructurally localized interfacial sliding Faults rather than in dislocation slip, Finite element modeling (FEM) is used to compute the shear stress distributions beneath the spherical indenters for selected experimental loading conditions, The underlying basis of the FEM calculations is an elastic-plastic constitutive relation based on a critical shear condition for yield, but incorporating a strain-hardening characteristic to allow for local elastic constraints on the sliding shear faults, The FEM calculations are able to simulate the main features of the stress-strain curves and the evolving deformation zone geometries. In addition, the calculated tensile stress distributions are able to account, at least in part, for the suppression of conventional brittle fracture tendencies in tougher ceramics. C1 NIST, MAT SCI & ENGN LAB, GAITHERSBURG, MD 20899 USA. NR 51 TC 75 Z9 75 U1 2 U2 20 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0002-7820 EI 1551-2916 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD OCT PY 1996 VL 79 IS 10 BP 2609 EP 2618 PG 10 WC Materials Science, Ceramics SC Materials Science GA VP021 UT WOS:A1996VP02100014 ER PT J AU FischerCripps, AC Lawn, BR Pajares, A Wei, LH AF FischerCripps, AC Lawn, BR Pajares, A Wei, LH TI Stress analysis of elastic-plastic contact damage in ceramic coatings on metal substrates SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID INDENTATION; ACCUMULATION; MECHANISMS; FATIGUE AB An elastic-plastic analysis of damage in ceramic coatings on metal substrates from contacts with spherical indenters is made using finite element modeling, Computations are carried out specifically for plasma-sprayed alumina:titania on a soft steel, The algorithm assumes an elastic sphere with frictionless contact on a flat elastic-plastic layered specimen, and incrementally evaluates the expanding contact field as a function of applied load, Two key aspects of the contact field are examined: (i) the indentation stress-strain curve; (ii) the damage zone geometry, Composite coating/substrate indentation stress-strain curves are computed for two coating thicknesses, using input material parameters from iterative fits to data from control tests on free-standing coating and substrate materials. Contours of principal shear stresses, most notably those contours corresponding to yield zone boundaries in both the softer substrate and the harder coating, are mapped out in the fully plastic region, Corresponding distributions of tensile stresses are also mapped out, and are shown to correlate with the locations of transverse fractures in the coating, General implications concerning material and geometrical design of ceramic-based layer structures are discussed. C1 NIST, MAT SCI & ENGN LAB, GAITHERSBURG, MD 20899 USA. RI Pajares, Antonia/I-3881-2015 OI Pajares, Antonia/0000-0002-1086-7586 NR 36 TC 41 Z9 43 U1 1 U2 8 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0002-7820 EI 1551-2916 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD OCT PY 1996 VL 79 IS 10 BP 2619 EP 2625 PG 7 WC Materials Science, Ceramics SC Materials Science GA VP021 UT WOS:A1996VP02100015 ER PT J AU Ashe, MJ Tripp, GA Eichmiller, FC George, LA Meiers, JC AF Ashe, MJ Tripp, GA Eichmiller, FC George, LA Meiers, JC TI Surface roughness of glass-ceramic insert-composite restorations: Assessing several polishing techniques SO JOURNAL OF THE AMERICAN DENTAL ASSOCIATION LA English DT Article AB The authors compared the effectiveness of seven polishing methods on glass-ceramic insert-composite restorations placed in plastic resin squares. The polishing methods used carbide dental finishing burs and diamond polishing paste, diamond abrasive finishing burs and diamond polishing paste, diamond abrasive finishing burs and composite resin finishing disks, diamond abrasive finishing burs and composite resin polishing points, diamond abrasive finishing burs only, diamond abrasive finishing burs followed by resin impregnated disks and an aluminum oxide polishing abrasive paste, and diamond abrasive finishing burs followed by diamond polishing paste. All systems achieved comparable smoothness except the carbide finishing burs, which damaged the insert-composite margin. C1 USN,SCH DENT,DEPT COMPREHENS DENT,BETHESDA,MD 20814. USN,SCH DENT,RES DEPT,BETHESDA,MD 20814. RP Ashe, MJ (reprint author), NATL INST STAND & TECHNOL,AMER DENT ASSOC HLTH FDN,BLDG 224,ROOM A153,GAITHERSBURG,MD 20899, USA. FU NIDCR NIH HHS [P50 DEO 9322] NR 6 TC 8 Z9 10 U1 0 U2 1 PU AMER DENTAL ASSN PI CHICAGO PA 211 E CHICAGO AVE, CHICAGO, IL 60611 SN 0002-8177 J9 J AM DENT ASSOC JI J. Am. Dent. Assoc. PD OCT PY 1996 VL 127 IS 10 BP 1495 EP 1500 PG 6 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA VL780 UT WOS:A1996VL78000014 PM 8908919 ER PT J AU Chai, H Chiang, MYM AF Chai, H Chiang, MYM TI A crack propagation criterion based on local shear strain in adhesive bonds subjected to shear SO JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS LA English DT Article DE fracture mechanisms; crack propagation and arrest; polymeric materials; crack mechanisms ID LAMINATED COMPOSITES; DEFORMATION; FRACTURE; FAILURE AB Direct observations show that the fracture of thin adhesive bonds subjected to shear is characterized by stable crack propagation along the interface followed by catastrophic growth. Other failure processes are observed during the stable growth phase, including crack kinking, development of a large void at the crack tip and formation of a detrimental interface micro-debond ahead of the main crack. The specific choice depends on factors such as the position of the precrack plane within the adhesive layer, the layer thickness and the loading level. Regardless of the specimen geometry, the entire interfacial crack propagation event is controlled by a single parameter-a critical shear strain at the crack tip that is independent of the bond thickness and the shearing direction but is a (decreasing) function of the crack velocity. The results can be useful in the application of fracture mechanics to the design of microlaminates, composites, traditional adhesive bonding and other technologies in which thin adhesive layers are used. C1 NATL INST STAND & TECHNOL,DIV POLYMERS,GAITHERSBURG,MD 20899. TEL AVIV UNIV,DEPT MECH MAT & STRUCT,IL-69978 TEL AVIV,ISRAEL. NR 20 TC 21 Z9 23 U1 1 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0022-5096 J9 J MECH PHYS SOLIDS JI J. Mech. Phys. Solids PD OCT PY 1996 VL 44 IS 10 BP 1669 EP 1689 DI 10.1016/0022-5096(96)00048-8 PG 21 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA VK573 UT WOS:A1996VK57300005 ER PT J AU Weinberg, JR Helser, TE AF Weinberg, JR Helser, TE TI Growth of the Atlantic surfclam, Spisula solidissima, from Georges Bank to the Delmarva Peninsula, USA SO MARINE BIOLOGY LA English DT Article ID PARAMETERS; AGE; CLAM; PERFORMANCE; EQUATION; TESTS; SHELL; SIZE AB Age/shell length data for offshore surfclam, Spisula solidissima (Dillwyn, 1817), populations were used to estimate the parameters of the von Bertalanffy growth model by time period and region, from Georges Bank in the north to the Delmarva Peninsula in the south. Randomization tests were used to compare curves. We tested the a priori hypothesis that growth curves would change over time in the ''south'' (i.e., New Jersey and Delmarva) but remain constant in the ''north'' (i.e., Long Island and South New England). This hypothesis was proposed because surfclam population structure in the ''south'' had been altered by the hypoxic event of 1976, and possibly by intense, long-term commercial harvesting. Northern regions, unaffected by these factors, served as natural controls. Based an a comparison of data collected in 1980 with pooled data from 1989 and 1992, the hypothesis was supported. Both the growth coefficient (k) and maximum shell length (L(infinity)) declined between two time periods in the two ''southern'' regions, while during the same time interval, no change occurred in the two ''northern'' regions. Differences in growth between regions were often statistically significant. For example, compared with the ''southern'' regions, the growth coefficient on Georges Bank was larger, and those clams attained a smaller maximum length. In a comparison of adjacent regions from Delmarva to S. New England, k increased from south to north. This could imply faster growth in cooler water, as well as no relationship between growth and primary productivity. Alternatively, size-selective mortality, imposed by the commercial fishery, was discussed as a mechanism that might account for this unexpected pattern. C1 NATL MARINE FISHERIES SERV,HOWARD MARINE SCI LAB,SANDY HOOK,NJ 07732. RP Weinberg, JR (reprint author), NATL MARINE FISHERIES SERV,POPULAT DYNAM BRANCH,WOODS HOLE,MA 02543, USA. NR 72 TC 23 Z9 24 U1 0 U2 3 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0025-3162 J9 MAR BIOL JI Mar. Biol. PD OCT PY 1996 VL 126 IS 4 BP 663 EP 674 DI 10.1007/BF00351333 PG 12 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA VR103 UT WOS:A1996VR10300011 ER PT J AU Levin, LA Talley, D Thayer, G AF Levin, LA Talley, D Thayer, G TI Succession of macrobenthos in a created salt marsh SO MARINE ECOLOGY PROGRESS SERIES LA English DT Article DE restoration; macrofauna; colonization; mitigation; community structure; life history; epifauna; Spartina alterniflora; dispersal; oligochaetes; polychaetes; Capitella spp ID SPARTINA-ALTERNIFLORA; LIFE-HISTORY; COMMUNITY; POLYCHAETE; DISTURBANCE; MACROFAUNA; MEIOFAUNA; PATTERNS; BAY; SEASONALITY AB Early succession of macrofauna was examined over several years in a created Spartina alterniflora marsh located on the Newport River Estuary, North Carolina, USA. Epifauna and infaunal community structure and composition were compared at 2 elevations in plots planted with S. alterniflora, plots left bare of vegetation and vegetated plots in a nearby natural S, alterniflora marsh. No significant successional differences were observed between vegetated and unvegetated sediments in the created marsh. The earliest stages of colonization involved recruitment by opportunistic estuarine polychaetes: Streblospio benedicti, Capitella spp, and Polydora cornuta. Capitella spp. dominated the macrofauna a month after marsh creation, but thereafter S. benedicti was the most abundant species. During the first few years, the artificial marsh retained early successional characteristics, with S, benedicti, Capitella spp. and turbellarians accounting for 75 to 95% of the total macrofauna. Fiddler crabs were common epifaunal colonists. After 4 yr, species richness increased and dominance by the early colonists diminished. Taxa lacking planktonic larvae and swimming adults were particularly slow to recover in the created marsh, but accounted for over 25% of the infauna by Year 4. Oligochaetes, which comprised over 50% of the fauna in the natural marsh, remained absent or rare in the artificial system throughout the study. Infaunal recovery appears to be more rapid in lower than upper marsh elevations. Although macrofaunal densities and species richness of sediments in the lower created marsh came to resemble those of the natural marsh within 6 mo, species composition and faunal feeding modes did not. These observations suggest there may be significant functional differences between young artificial marshes and older natural marshes. Consideration of the timing of marsh creation, marsh configuration, continuity with natural marshes, seeding of taxa with poor dispersal, and attention to species habitat requirements are recommended to accelerate infaunal colonization of created Spartina marshes. C1 NATL MARINE FISHERIES SERV, BEAUFORT LAB, BEAUFORT, NC 28516 USA. RP Levin, LA (reprint author), UNIV CALIF SAN DIEGO, MARINE LIFE RES GRP, LA JOLLA, CA 92093 USA. NR 45 TC 83 Z9 87 U1 4 U2 20 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0171-8630 J9 MAR ECOL PROG SER JI Mar. Ecol.-Prog. Ser. PD OCT PY 1996 VL 141 IS 1-3 BP 67 EP 82 DI 10.3354/meps141067 PG 16 WC Ecology; Marine & Freshwater Biology; Oceanography SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Oceanography GA VN380 UT WOS:A1996VN38000008 ER PT J AU Duignan, PJ House, C Odell, DK Wells, RS Hansen, LJ Walsh, MT StAubin, DK Rima, BK Geraci, JR AF Duignan, PJ House, C Odell, DK Wells, RS Hansen, LJ Walsh, MT StAubin, DK Rima, BK Geraci, JR TI Morbillivirus infection in bottlenose dolphins: Evidence for recurrent epizootics in the western Atlantic and Gulf of Mexico SO MARINE MAMMAL SCIENCE LA English DT Article DE bottlenose dolphin; Tursiops truncatus; morbillivirus; serology; epizootic; pilot whales; Globicephala spp ID TURSIOPS-TRUNCATUS; NOSED-DOLPHIN; STENELLA-COERULEOALBA; PORPOISE; BEHAVIOR; DISEASE AB Morbillivirus infection is widespread among odontocetes of the western Atlantic and Gulf of Mexico. Serologic evidence of infection in bottlenose dolphins, Tursiops truncatus, was first detected during an epizootic along the mid-Atlantic tease in 1987. Here, we report recurrent epizootics in the coastal dolphin population since at least the early 1980s based on serological surveys and regional stranding frequencies. The first observed epizootic of this series occurred in the Indian and Banana Rivers in 1982 and was followed by others on the mid-Atlantic coast in 1987-1988 and in the Gulf of Mexico between 1992 and 1994. This temporal pattern of infection is likely facilitated by the population size and its fragmentation into relatively discrete coastal communities. Introduction of morbillivirus into a community with a sufficient number of naive hosts may precipitate an epizootic, depending on the potential for transmission within the group. Propagation of an epizootic along the cease is probably determined by frequency of contact between adjacent communities and seasonal migrations. Morbillivirus antibodies were also detected in serum from offshore bottle-nose dolphins. The sere-prevalence in the latter may be higher than in coastal dolphins because of their close association with enzootically infected pilot whales (Globicephala spp.). Occasional contact between offshore and coastal dolphins may provide an epizootiologic link between pilot whales and coastal dolphin communities. C1 NATL VET SERV LAB,FOREIGN ANIM DIS DIAGNOST LAB,GREENPORT,NY 11944. MOTE MARINE LAB,CHICAGO ZOOL SOC,SARASOTA,FL 34236. NOAA,NATL MARINE FISHERIES SERV,SE FISHERIES SCI CTR,CHARLESTON LAB,CHARLESTON,SC 29412. SEA WORLD FLORIDA,ORLANDO,FL 32821. MYST MARINELIFE AQUARIUM,MYSTIC,CT 06355. QUEENS UNIV BELFAST,SCH BIOL & BIOCHEM,DIV MOL BIOL,BELFAST BT9 7BL,ANTRIM,NORTH IRELAND. RP Duignan, PJ (reprint author), UNIV GUELPH,ONTARIO VET COLL,DEPT PATHOL,GUELPH,ON N1G 2W1,CANADA. NR 50 TC 39 Z9 43 U1 1 U2 12 PU SOC MARINE MAMMALOGY PI LAWRENCE PA 1041 NEW HAMPSHIRE ST, LAWRENCE, KS 66044 SN 0824-0469 J9 MAR MAMMAL SCI JI Mar. Mamm. Sci. PD OCT PY 1996 VL 12 IS 4 BP 499 EP 515 PG 17 WC Marine & Freshwater Biology; Zoology SC Marine & Freshwater Biology; Zoology GA VL334 UT WOS:A1996VL33400001 ER PT J AU Boveng, PL Walker, BG Bengtson, JL AF Boveng, PL Walker, BG Bengtson, JL TI Variability in Antarctic fur seal dive data: Implications for TDR studies SO MARINE MAMMAL SCIENCE LA English DT Article DE Arctocephalus gazella; Antarctic fur seal; time-depth recorders; diving; sample size; experimental design ID DIVING BEHAVIOR; STATISTICAL POWER; SAMPLE-SIZE; DEPTH; TIME AB We analyzed 19 dive records obtained from female antarctic fur seals (Arctocephalus gazella) during three austral summer breeding seasons on Seal Island, Antarctica, to assess the extent of individual variation and the potential for using time-depth recorder (TDR) statistics to detect annual changes in six measures of foraging behavior. We report the mean values and typical variability among individuals for dive duration, dive depth, proportion of time submerged, transit time, vertical distance dived, and diving intensity. Dive duration was the least variable and vertical distance dived was the most variable among individual seals. The results were used to estimate the sample sizes required to detect-with acceptable precision and power-differences in the six measures between sites, years, or species. Statistics that vary most among individuals require the largest sample sizes to reliably detect a given percentage difference between annual means. Interestingly, we also observed the most significant interannual differences in those same statistics. These results emphasize that specifying the magnitude of the (interannual, intersite or interspecific) difference that is biologically significant to the study population is an important, though sometimes difficult, component of TDR survey design. RP Boveng, PL (reprint author), NOAA,ALASKA FISHERIES SCI CTR,NATL MARINE MAMMAL LAB,7600 SAND POINT WAY NE,BLDG 4,SEATTLE,WA 98115, USA. NR 29 TC 12 Z9 12 U1 2 U2 2 PU SOC MARINE MAMMALOGY PI LAWRENCE PA 1041 NEW HAMPSHIRE ST, LAWRENCE, KS 66044 SN 0824-0469 J9 MAR MAMMAL SCI JI Mar. Mamm. Sci. PD OCT PY 1996 VL 12 IS 4 BP 543 EP 554 PG 12 WC Marine & Freshwater Biology; Zoology SC Marine & Freshwater Biology; Zoology GA VL334 UT WOS:A1996VL33400004 ER PT J AU Muzny, CD Butler, BD Hanley, HJM Tsvetkov, F Peiffer, DG AF Muzny, CD Butler, BD Hanley, HJM Tsvetkov, F Peiffer, DG TI Clay platelet dispersion in a polymer matrix SO MATERIALS LETTERS LA English DT Article DE clay/polymer nanocomposite; clay dispersion; dynamic light scattering; clay-micelle complex ID ANGLE NEUTRON-SCATTERING; LIGHT-SCATTERING; LAPONITE; MONTMORILLONITE; NANOCOMPOSITES; HYBRID; SUSPENSIONS AB A dispersed clay/polymer nanocomposite was prepared by joining, via a cationic exchange reaction, surfactant monomers to clay platelets and subsequently polymerizing them with acrylamide. Dispersion was made possible by preparing a clay surfactant precursor solution, with the surfactant in sufficient excess to form clay-micelle complexes that resist platelet aggregation. This homogeneous nanoscale dispersion of platelets was verified using dynamic light scattering. C1 NATL INST STAND & TECHNOL,DIV THERMOPHYS,BOULDER,CO 80303. SOLAR DYNAM LTD,IL-77166 ASHDOD,ISRAEL. EXXON RES & ENGN CO,ANNANDALE,NJ 08801. NR 25 TC 43 Z9 45 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-577X J9 MATER LETT JI Mater. Lett. PD OCT PY 1996 VL 28 IS 4-6 BP 379 EP 384 DI 10.1016/0167-577X(96)00085-7 PG 6 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA VQ345 UT WOS:A1996VQ34500026 ER PT J AU Hudson, LT Deslattes, RD Henins, A Chantler, CT Kessler, EG Schweppe, JE AF Hudson, LT Deslattes, RD Henins, A Chantler, CT Kessler, EG Schweppe, JE TI Curved crystal spectrometer for energy calibration and spectral characterization of mammographic x-ray sources SO MEDICAL PHYSICS LA English DT Article DE curved crystal spectrometry; diffraction; high voltage; mammography; x-rays ID SCATTERING; QUALITY; KV AB Clinical efficacy of diagnostic radiology for mammographic examinations is critically dependent on source characteristics, detection efficiency, image resolution and applied high voltage. In this report we focus on means for evaluation of source-dependent issues including noninvasive determination of the applied high voltage, and characterization of intrinsic spectral distributions which in turn reflect the effects of added filtration and target and window contamination. It is shown that a particular form of x-ray curved crystal spectrometry with electronic imaging can serve to determine all relevant parameters within the confines of a standard clinical exposure. (C) 1996 American Association of Physicists in Medicine. RP Hudson, LT (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. RI Chantler, Christopher/D-4744-2013 OI Chantler, Christopher/0000-0001-6608-0048 NR 32 TC 38 Z9 38 U1 1 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0094-2405 J9 MED PHYS JI Med. Phys. PD OCT PY 1996 VL 23 IS 10 BP 1659 EP 1670 DI 10.1118/1.597845 PG 12 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA VN499 UT WOS:A1996VN49900001 PM 8946364 ER PT J AU Suehle, JS Chaparala, P AF Suehle, JS Chaparala, P TI Characterization of time-dependent dielectric breakdown in intrinsic thin SiO2 SO MICROELECTRONICS JOURNAL LA English DT Article; Proceedings Paper CT 6th ESPRIT Workshop on the Characterisation and Growth of Thin Dielectrics in Microelectronics CY NOV 22-23, 1994 CL KINSALE, IRELAND SP EC, NMRC AB Time-dependent dielectric breakdown data collected from 6.5-, 9-, 15-, 20- and 22.5-nm-thick SiO2 films are presented. The failure distributions are of single mode with no apparent extrinsic population. The logarithm of the median-test-time-to failure, log(t(50)), is described by a linear electric field dependence. Contrary to reports in earlier studies, the field acceleration parameter is observed to be insensitive to temperature and has a value of approximately 1.0 decade MV(-1) cm(-1) for the range of oxide thicknesses studied. Capacitance-voltage studies indicate chat there is no strong correlation between oxide trapped charges and time to failure under constant voltage stress conditions. Published by Elsevier Science Ltd. C1 UNIV MARYLAND,CTR RELIABIL ENGN,COLLEGE PK,MD 20742. RP Suehle, JS (reprint author), NIST,DIV SEMICOND ELECT,GAITHERSBURG,MD 20899, USA. NR 14 TC 7 Z9 7 U1 0 U2 0 PU ELSEVIER ADVANCED TECHNOLOGY PI OXFORD PA OXFORD FULFILLMENT CENTRE THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0026-2692 J9 MICROELECTR J JI Microelectron. J. PD OCT PY 1996 VL 27 IS 7 BP 657 EP 665 DI 10.1016/0026-2692(95)00103-4 PG 9 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology SC Engineering; Science & Technology - Other Topics GA VJ118 UT WOS:A1996VJ11800007 ER PT J AU Hong, SY Pan, HL AF Hong, SY Pan, HL TI Nonlocal boundary layer vertical diffusion in a Medium-Range Forecast Model SO MONTHLY WEATHER REVIEW LA English DT Article ID NATIONAL-METEOROLOGICAL-CENTER; TRANSILIENT TURBULENCE THEORY; SOIL HYDROLOGY; CLIMATE MODEL; PARAMETERIZATION; COORDINATE; SCHEMES; SYSTEM; LAND; FLUX AB In this paper, the incorporation of a simple atmospheric boundary laver diffusion scheme into the NCEP Medium-Range Forecast Model is described. A boundary layer diffusion package based on the Troen and Mahrt nonlocal diffusion concept has been tested for possible operational implementation. The results from this approach are compared with those from the local diffusion approach, which is the current operational scheme, and verified against FIFE observations during 9-10 August 1987. The comparisons between local and nonlocal approaches are extended to the forecast for a heavy rain case of 15-17 May 1995. The sensitivity of both the boundary layer development and the precipitation forecast to the tuning parameters in the nonlocal diffusion scheme is also investigated. Special attention is given to the interaction of boundary layer processes with precipitation physics. Some results of parallel runs during August 1995 are also presented. RP Hong, SY (reprint author), NCEP, EMC, ROOM 207, 5200 AUTH RD, CAMP SPRINGS, MD 20746 USA. RI Hong, Song-You/I-3824-2012 NR 44 TC 1284 Z9 1360 U1 4 U2 67 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD OCT PY 1996 VL 124 IS 10 BP 2322 EP 2339 DI 10.1175/1520-0493(1996)124<2322:NBLVDI>2.0.CO;2 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VL888 UT WOS:A1996VL88800012 ER PT J AU Shabbar, A Barnston, AG AF Shabbar, A Barnston, AG TI Skill of seasonal climate forecasts in Canada using canonical correlation analysis SO MONTHLY WEATHER REVIEW LA English DT Article ID NINO-SOUTHERN OSCILLATION; NORTHERN-HEMISPHERE; STATISTICAL-MODELS; PATTERNS; TEMPERATURE; CYCLE; PREDICTABILITY; PRECIPITATION; PREDICTION; ENSO AB An empirical system for forecasting 3-month mean surface temperature T and total precipitation P for Canada-canonical correlation analysis (CCA) -has been developed using the 1956-90 data period. The levels and sources of predictive skill have been estimated for all seasons at lead times of up to one year, using a cross-validation design. The predictor fields are quasi-global sea surface temperature (SST). Northern Hemisphere 500-mb geopotential height, and for T forecasts prior values of T itself. Four consecutive 3-month predictor periods are used to detect evolving as well as steady-state conditions in the predictor fields. While forecast skills are modest for much of the year, winter and spring skills for T forecasts at a 3-month lead time are both highly statistically field significant and good enough to be beneficial to appropriate users. These forecasts average a 0.3-0.4 correlation skill nationwide and greater than 0.6 in the southeastern prairies. Forecast skill for P averages a lower but still statistically field significant 0.2 in winter with local maxima of greater than 0.5 along parts of southern Canada. A weak secondary seasonal maximum in T forecast skill is found in summer. CCA forecasts generally outperform persistence forecasts, and their skill declines only slowly as lead time is increased. Thus, useful forecasts can be made for certain seasons/regions of Canada several seasons in advance. The CCA diagnostics indicate that the El Nino/Southern Oscillation (ENSO) plays a dominant role in Canadian T anomalies in winter and spring, and P anomalies in winter. Warm SO (El Nino) episodes tend to force positive winter and spring T anomalies in much of western and southern Canada, and suppressed P in roughly similar portions of the country. Below normal T tends to occur in northeastern Canada, and above normal F in the southeastern Northwest Territory, during warm SO episodes. Because of the linearity of CCA, opposite responses are implied for cold SO episodes. Another important skill source for Canadian winter forecasts is associated with a long-term trend in global SST. Between the 1950s and the 1990s the high (low) latitude SST has tended to cool (warm). The Canadian winter T response has been a cooling from northern Quebec to northeastern Canada and warming in northwest Canada, while a trend toward greater (lighter) P in the northern (southern) prairies is noted. Knowledge of such trends can greatly aid in forecasting anomalies that are defined using normals for a period centered in the past. In conclusion, statistically based long-lead forecasts of surface climate are shown to deliver useful kill in Canada. This approach also provides a skill benchmark against which the skill of dynamical models can be compared as they enter the forecasting arena. C1 NOAA,NATL WEATHER SERV,NATL CTR ENVIRONM PREDICT,CLIMATE PREDICT CTR,WASHINGTON,DC. RP Shabbar, A (reprint author), ATMOSPHER ENVIRONM SERV,4905 DUFFERIN ST,DOWNSVIEW,ON M3H 5T4,CANADA. NR 27 TC 77 Z9 81 U1 0 U2 5 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD OCT PY 1996 VL 124 IS 10 BP 2370 EP 2385 DI 10.1175/1520-0493(1996)124<2370:SOSCFI>2.0.CO;2 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VL888 UT WOS:A1996VL88800015 ER PT J AU Grimes, SM Brient, CE Goeckner, FC Bateman, FB Chadwick, MB Haight, RC Lee, TM Sterbenz, SM Young, PG Wasson, OA Vonach, H AF Grimes, SM Brient, CE Goeckner, FC Bateman, FB Chadwick, MB Haight, RC Lee, TM Sterbenz, SM Young, PG Wasson, OA Vonach, H TI The Co-59(n,x alpha) reaction from 5 to 50 MeV SO NUCLEAR SCIENCE AND ENGINEERING LA English DT Article ID CONTINUUM ANGULAR-DISTRIBUTIONS; 15-MEV NEUTRONS; SYSTEMATICS; ISOTOPES; EMISSION; ENERGIES; CARBON AB Alpha-particle production cross sections and spectra produced by neutron bombardment of Co-59 are measured at 30, 60, 90, and 135 deg over the neutron energy range from 5 to 50 MeV. A source of neutrons continuous in energy is provided by the Los Alamos Weapons Nuclear Research Facility spallation neutron source facility. Comparison of the measurements with results of calculations including sequential reaction Hauser-Feshbach calculations and pre-equilibrium processes indicates that the majority of the alpha particles result from compound nuclear reactions. The degree of agreement of calculation with experimental data for the cross section as a function of neutron energy and on the alpha-particle emission spectra depends on the selection of nuclear level densities and optical model parameters. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. NIST,GAITHERSBURG,MD 20899. INST RADIUMFORSCH & KERNPHYS,A-1090 VIENNA,AUSTRIA. UNIV WISCONSIN,DEPT MED PHYS,MADISON,WI 53706. RP Grimes, SM (reprint author), OHIO UNIV,DEPT PHYS,ATHENS,OH 45701, USA. NR 33 TC 16 Z9 16 U1 1 U2 3 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 SN 0029-5639 J9 NUCL SCI ENG JI Nucl. Sci. Eng. PD OCT PY 1996 VL 124 IS 2 BP 271 EP 279 PG 9 WC Nuclear Science & Technology SC Nuclear Science & Technology GA VK791 UT WOS:A1996VK79100006 ER PT J AU Borchers, JA Gehring, PM Erwin, RW Ankner, JF Majkrzak, CF Hylton, TL Coffey, KR Parker, MA Howard, JK AF Borchers, JA Gehring, PM Erwin, RW Ankner, JF Majkrzak, CF Hylton, TL Coffey, KR Parker, MA Howard, JK TI Antiferromagnetic interlayer correlations in annealed Ni80Fe20/Ag multilayers SO PHYSICAL REVIEW B LA English DT Article ID DISCONTINUOUS MAGNETIC MULTILAYERS; SPIN-VALVE STRUCTURES; X-RAY-DIFFRACTION; GIANT MAGNETORESISTANCE; DIFFUSE-SCATTERING; THIN-FILMS; LOW FIELDS; SUPERLATTICES; ROUGHNESS; REFLECTION AB Sputtered Ni80Fe20/Ag multilayers, annealed post-growth, exhibit giant magnetoresistance (GMR) with pronounced field sensitivity [T. L. Hylton et al., Science 261, 1021 (1993)], We have characterized a series of Ni80Fe20(20 Angstrom)/Ag(40 Angstrom) multilayers annealed at temperatures ranging from 305 to 335 degrees C using x-ray and polarized neutron reflectivity techniques. For all of the samples, specular x-ray measurements reveal that the laterally averaged interfaces between the Ni80Fe20 and Ag layers are not well defined. The growth-plane morphology of the multilayers, determined from off-specular x-ray diffraction, shows a dependence on annealing temperature. Specular and off-specular polarized neutron reflectivity data indicate that the GMR in the annealed samples does not arise from long-range antiferromagnetic alignment of coherent ferromagnetic sheets, as generally observed in related materials. Instead, annealing promotes the formation of planar ferromagnetic domains of micrometer size within each Ni80Fe20 layer that are antiferromagnetically correlated along the growth axis. The length scales of these domains are consistent with a model in which weak dipolar forces dominate the interactions between them. C1 UNIV MISSOURI,RES REACTOR FACIL,COLUMBIA,MO 65211. RP Borchers, JA (reprint author), NATL INST STAND & TECHNOL,DIV REACTOR RADIAT,GAITHERSBURG,MD 20899, USA. OI Ankner, John/0000-0002-6737-5718; Gehring, Peter/0000-0002-9236-2046 NR 47 TC 29 Z9 29 U1 2 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD OCT 1 PY 1996 VL 54 IS 14 BP 9870 EP 9882 DI 10.1103/PhysRevB.54.9870 PG 13 WC Physics, Condensed Matter SC Physics GA VM546 UT WOS:A1996VM54600051 ER PT J AU Wu, SY Li, WH Lee, KC Lynn, JW Meen, TH Yang, HD AF Wu, SY Li, WH Lee, KC Lynn, JW Meen, TH Yang, HD TI Two- and three-dimensional magnetic correlations of tb in Pb2Sr2TbCu3O8 SO PHYSICAL REVIEW B LA English DT Article ID RARE-EARTH IONS; NEUTRON-SCATTERING; ORDER; PR; GD; SUPERCONDUCTIVITY; FLUCTUATIONS; ERBA2CU3O7; BEHAVIOR; ER AB The magnetic order of the Tb ions in polycrystalline Pb(2)Sr(2)TbCu3O(8) has been studied by neutron-diffraction and ac-susceptibility measurements. Magnetic correlations are observed to develop below T approximate to 9 K, and the correlation length diverges at T-N=5.3 K. At high temperatures the in-phase component of the ac susceptibility chi' exhibits Curie-Weiss behavior, while it departs from this behavior as the magnetic correlations between the Tb ions develop, and exhibits a cusp at lower temperatures characteristic of antiferromagnetic ordering. The T-N determined from the critical behavior of the correlation length measured by neutron diffraction is in good agreement with that determined by the relative maximum in d chi'/dT. Both two-dimensional (2D) and three-dimensional Bragg peaks are observed, but the magnetic correlations are predominantly 2D in nature. The sublattice magnetization drops sharply as the critical point is approached, as is typical for low-dimensional systems, and the value of 1.00(5) obtained for the critical exponent nu agrees very well with nu=1 for the S=1/2 2D Ising model. C1 NATL INST STAND & TECHNOL,DIV REACTOR RADIAT,GAITHERSBURG,MD 20899. NATL SUN YAT SEN UNIV,DEPT PHYS,KAOHSIUNG 80424,TAIWAN. RP Wu, SY (reprint author), NATL CENT UNIV,DEPT PHYS,CHUNGLI 32054,TAIWAN. NR 31 TC 12 Z9 12 U1 1 U2 5 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD OCT 1 PY 1996 VL 54 IS 14 BP 10019 EP 10026 DI 10.1103/PhysRevB.54.10019 PG 8 WC Physics, Condensed Matter SC Physics GA VM546 UT WOS:A1996VM54600068 ER PT J AU Barton, CE Baldwin, RT Barraclough, DR Bushati, S Chiappini, M Cohen, Y Coleman, R Hulot, G Kotze, P Golovkov, VP Jackson, A Langel, RA Lowes, FJ McKnight, DJ Macmillan, S Newitt, LR Peddie, NW Quinn, JM Sabaka, TJ AF Barton, CE Baldwin, RT Barraclough, DR Bushati, S Chiappini, M Cohen, Y Coleman, R Hulot, G Kotze, P Golovkov, VP Jackson, A Langel, RA Lowes, FJ McKnight, DJ Macmillan, S Newitt, LR Peddie, NW Quinn, JM Sabaka, TJ TI International Geomagnetic Reference Field, 1995 revision - Presented by IAGA Division V, Working Group 8 SO PHYSICS OF THE EARTH AND PLANETARY INTERIORS LA English DT Letter C1 RUSSIAN ACAD SCI,RUSSIAN GEOPHYS COMM,MOSCOW 117296,RUSSIA. BRITISH GEOL SURVEY,WORLD DATA CTR C1 GEOMAGNETISM,EDINBURGH EH9 3LA,MIDLOTHIAN,SCOTLAND. KYOTO INST TECHNOL,FAC SCI,WORLD DATA CTR C2 GEOMAGNETISM,KYOTO 606,JAPAN. NASA,GODDARD SPACE FLIGHT CTR,WORLD DATA CTR A ROCKETS & SATELLITES,GREENBELT,MD 20771. RP Barton, CE (reprint author), NOAA,NATL GEOPHYS DATA CTR,WORLD DATA CTR A SOLID EARTH GEOPHYS,CODE E-GCI,325 BROADWAY,BOULDER,CO 80303, USA. RI Hulot, Gauthier/A-5627-2011; Sabaka, Terence/D-5618-2012; Cohen, Yves/A-4521-2013 NR 9 TC 12 Z9 12 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0031-9201 J9 PHYS EARTH PLANET IN JI Phys. Earth Planet. Inter. PD OCT PY 1996 VL 97 IS 1-4 BP 23 EP 26 DI 10.1016/0031-9201(96)03139-1 PG 4 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA VP185 UT WOS:A1996VP18500004 ER PT J AU Estler, WT Phillips, SD Borchardt, B Hopp, T Witzgall, C Levenson, M Eberhardt, K McClain, M Shen, Y Zhang, X AF Estler, WT Phillips, SD Borchardt, B Hopp, T Witzgall, C Levenson, M Eberhardt, K McClain, M Shen, Y Zhang, X TI Error compensation for CMM touch trigger probes SO PRECISION ENGINEERING-JOURNAL OF THE AMERICAN SOCIETY FOR PRECISION ENGINEERING LA English DT Article DE coordinate measuring machines; dimensional metrology; error correction; modeling; touch trigger probes AB We present the analysis of a simple mechanical model ofa common type of kinematic seat touch trigger probe widely used on modern coordinate measuring machines (CMMs). The model provides a quantitative description of the pretravel variation or ''probe-lobing'' characteristics that limit the use of such probes for high-accuracy dimensional measurements. We include the effects of stylus bending and the frictional interaction between the stylus ball and the part surface. The model is restricted to probes with simple straight styli, and we demonstrate significant error reduction both for vertically and horizontally oriented styli. In the latter case, gravitational forces are shown to play an important role in probe triggering and pretravel variation. Extensions to arbitrary orientations are discussed. RP Estler, WT (reprint author), NIST,DIV PRECIS ENGN,METROL B113,GAITHERSBURG,MD 20899, USA. NR 11 TC 41 Z9 43 U1 2 U2 8 PU BUTTERWORTH-HEINEMANN PI WOBURN PA 225 WILDWOOD AVE #UNITB PO BOX 4500, WOBURN, MA 01801-2084 SN 0141-6359 J9 PRECIS ENG JI Precis. Eng.-J. Am. Soc. Precis. Eng. PD OCT-NOV PY 1996 VL 19 IS 2-3 BP 85 EP 97 DI 10.1016/S0141-6359(96)00040-2 PG 13 WC Engineering, Multidisciplinary; Engineering, Manufacturing; Nanoscience & Nanotechnology; Instruments & Instrumentation SC Engineering; Science & Technology - Other Topics; Instruments & Instrumentation GA VX710 UT WOS:A1996VX71000001 ER PT J AU Vorburger, TV Song, JF Giauque, CHW Renegar, TB Whitenton, EP Croarkin, MC AF Vorburger, TV Song, JF Giauque, CHW Renegar, TB Whitenton, EP Croarkin, MC TI Stylus-laser surface calibration system SO PRECISION ENGINEERING-JOURNAL OF THE AMERICAN SOCIETY FOR PRECISION ENGINEERING LA English DT Article DE calibration; stylus-laser; roughness; sinusoidal profiles; stylus instruments; surface texture; traceability; uncertainty ID SPECIMENS AB A stylus-laser surface calibration system was developed to calibrate the NIST sinusoidal roughness Standard Reference Materials (SRM) 2071-2075. Step height standards are used to calibrate the stylus instrument in the vertical direction, and a laser interferometer is mounted on the traversing unit of the stylus instrument to calibrate the instrument in the horizontal direction. The calibration uncertainty (+/- 2 sigma) for SRM 2075 is +/- 1.2% for roughness calibrations (R(a) = 1 mu m), and +/- 0.06% for spatial wavelength calibrations (S-m = 800 mu m). RP Vorburger, TV (reprint author), NIST,DIV PRECIS ENGN,QUINCE ORCHARD BLVD,GAITHERSBURG,MD 20899, USA. NR 18 TC 4 Z9 4 U1 1 U2 1 PU BUTTERWORTH-HEINEMANN PI WOBURN PA 225 WILDWOOD AVE #UNITB PO BOX 4500, WOBURN, MA 01801-2084 SN 0141-6359 J9 PRECIS ENG JI Precis. Eng.-J. Am. Soc. Precis. Eng. PD OCT-NOV PY 1996 VL 19 IS 2-3 BP 157 EP 163 DI 10.1016/S0141-6359(96)00043-8 PG 7 WC Engineering, Multidisciplinary; Engineering, Manufacturing; Nanoscience & Nanotechnology; Instruments & Instrumentation SC Engineering; Science & Technology - Other Topics; Instruments & Instrumentation GA VX710 UT WOS:A1996VX71000008 ER PT J AU Ramaswamy, V Li, J AF Ramaswamy, V Li, J TI A line-by-line investigation of solar radiative effects in vertically inhomogeneous low clouds SO QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY LA English DT Article DE cloud optical properties; inhomogeneous cloud; radiative-transfer model; solar-radiation scattering ID AIRCRAFT OBSERVATIONS; MARINE STRATUS; WATER-VAPOR; ABSORPTION; STRATOCUMULUS; PARAMETERIZATION; FIELDS; MODELS; ATMOSPHERES; DROPS AB Using a detailed line-by-line, multiple-scattering solar radiative-transfer model, the influences due to cloud internal inhomogeneity in the Vertical upon the solar radiative transfer are investigated. In particular, the consequences due to non-uniform vertical profiles of liquid water and droplet sizes within low clouds are explored in a systematic manner. The fine structure of the spectral overlap between the water droplet and water vapour optical properties, and its effects upon the radiation absorbed within the cloud layer and that reflected at the top of the cloud, are discussed. Without consideration of the in-cloud water vapour, a vertically inhomogeneous cloud with properties resembling those observed absorbs more solar radiation than an equivalent homogeneous cloud. However, consideration of the effects of the in-cloud vapour, while still leading to a slightly greater absorption for the inhomogeneous case, partly offsets the difference introduced by the vertical distribution of the drop microphysics. The vertical distribution of cloud heating rate is changed substantially because of the inhomogeneity in the microphysics, with the heating rate in the top region of the cloud nearly 50% more than that due to an equivalent vertically homogeneous cloud. Vertical inhomogeneity of cloud microphysics has little influence on the broadband solar albedo, but can cause significant decreases of the cloud reflectance at specific near-infrared wavelengths i.e. wavelengths greater than 1 mu m, (equivalently, wave numbers less than 10 000 cm(-1)). RP Ramaswamy, V (reprint author), PRINCETON UNIV,NOAA,GEOPHYS FLUID DYNAM LAB,POB 308,PRINCETON,NJ 08542, USA. RI Li, Jiangnan/J-6262-2016 NR 29 TC 6 Z9 6 U1 1 U2 4 PU ROYAL METEOROLOGICAL SOC PI READING PA 104 OXFORD ROAD, READING, BERKS, ENGLAND RG1 7LJ SN 0035-9009 J9 Q J ROY METEOR SOC JI Q. J. R. Meteorol. Soc. PD OCT PY 1996 VL 122 IS 536 BP 1873 EP 1890 DI 10.1256/smsqj.53606 PN B PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VY346 UT WOS:A1996VY34600006 ER PT J AU Szabo, S Coombs, D Herman, M Camus, T Liu, HC AF Szabo, S Coombs, D Herman, M Camus, T Liu, HC TI A real-time computer vision platform for mobile robot applications SO REAL-TIME IMAGING LA English DT Article ID OPTICAL-FLOW AB A portable platform is described that supports real-time computer vision applications for mobile robots. This platform includes conventional processors, an image processing front-end system, and a controller for a pan/tilt/vergence head. The platform is ruggedized to withstand vibration during off-road driving. The platform has successfully supported experiments in video stabilization and detection of moving objects for outdoor surveillance, gradient-based and correlation-based image flow estimators, and indoor mobility using divergence of flow. These applications have been able to run at rates ranging from 3 to 15 Hz for image sizes from 64 X 64 to 256 X 256. (C) 1996 Academic Press Limited RP NIST, INTELLIGENT SYST DIV, BLDG 220, ROOM B-124, GAITHERSBURG, MD 20899 USA. NR 26 TC 1 Z9 2 U1 2 U2 2 PU ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 1077-2014 J9 REAL-TIME IMAGING JI Real-Time Imaging PD OCT PY 1996 VL 2 IS 5 BP 315 EP 327 DI 10.1006/rtim.1996.0032 PG 13 WC Computer Science, Artificial Intelligence; Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA VR711 UT WOS:A1996VR71100005 ER PT J AU Tassey, G AF Tassey, G TI Choosing government R&D policies: Tax incentives vs direct funding SO REVIEW OF INDUSTRIAL ORGANIZATION LA English DT Article DE technology; innovation; policy; market failure; tax; funding AB A major policy debate continues in many industrialized nations over the rationales for government support of technology development. This debate is unstructured due to the weakness of the underlying economics. Government intervention at any stage in the economic process is based on the recognition of market failure. In the case of technology-based markets, a rather vague allusion to excessive risk is often the best rationale put forward. Real risk/reward ratios are often distorted, leading to underinvestment, but the causes are several and vary significantly in character. As a result of this variance, the appropriate policy response also varies, ranging from varying tax incentives to direct government funding of R&D. RP Tassey, G (reprint author), NATL INST STAND & TECHNOL,ADMIN 1000,GAITHERSBURG,MD 20899, USA. NR 22 TC 12 Z9 12 U1 0 U2 8 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0889-938X J9 REV IND ORGAN JI Rev. Ind. Organ. PD OCT PY 1996 VL 11 IS 5 BP 579 EP 600 DI 10.1007/BF00214824 PG 22 WC Economics; Management SC Business & Economics GA VE944 UT WOS:A1996VE94400002 ER PT J AU Newbury, DE AF Newbury, DE TI Imaging deep holes in structures with gaseous secondary electron detection in the environmental scanning electron microscope SO SCANNING LA English DT Article DE environmental scanning electron microscopy; gaseous secondary electron detector; holes; image formation; microstructures; scanning electron microscopy AB The gaseous secondary electron detector (GSED) in the environmental scanning electron microscope (ESEM) permits collection of electron signals from deep inside blind holes in both conducting and insulating materials. The placement of the GSED as the final pressure-limiting aperture of the ESEM creates a situation of apparent illumination along the line of sight of the observer. In principle, any point struck by the primary beam can be imaged. Image quality depends on the depth of the hole. In brass, features at the bottom of a 1.5 mm diameter hole that was 8 mm deep were successfully imaged. RP Newbury, DE (reprint author), NATL INST STAND & TECHNOL,SURFACE & MICRONANL SCI DIV,BLDG 222,ROOM A113,GAITHERSBURG,MD 20899, USA. NR 5 TC 9 Z9 9 U1 0 U2 0 PU FAMS INC PI MAHWAH PA BOX 832, MAHWAH, NJ 07430 SN 0161-0457 J9 SCANNING JI Scanning PD OCT PY 1996 VL 18 IS 7 BP 474 EP 482 PG 9 WC Instruments & Instrumentation; Microscopy SC Instruments & Instrumentation; Microscopy GA VN102 UT WOS:A1996VN10200003 ER PT J AU Taylor, ME Wight, SA AF Taylor, ME Wight, SA TI A new method for low-magnification in the environmental scanning electron microscope SO SCANNING LA English DT Article DE low magnification; environmental scanning electron microscope; secondary electron detector; pressure-limiting aperture ID ESEM AB A device has been developed and used successfully on two models of the environmental scanning electron microscope that allows low-magnification imaging of about 30x, significantly better than the original 200x low-magnification imaging limit. This was achieved by using an additional aperture to limit the pressure at a point where it will not block the electron beam, and a larger aperture plate for the combination final aperture/secondary electron signal collection surface that also does not block the electron beam significantly. C1 NIST,CHEM A113,GAITHERSBURG,MD 20899. UNIV MARYLAND,DEPT MAT & NUCL ENGN,COLLEGE PK,MD 20742. NR 11 TC 2 Z9 2 U1 0 U2 1 PU FAMS INC PI MAHWAH PA BOX 832, MAHWAH, NJ 07430 SN 0161-0457 J9 SCANNING JI Scanning PD OCT PY 1996 VL 18 IS 7 BP 483 EP 489 PG 7 WC Instruments & Instrumentation; Microscopy SC Instruments & Instrumentation; Microscopy GA VN102 UT WOS:A1996VN10200004 ER PT J AU Pandey, PC Singh, S Upadhyay, B Weetall, HH Chen, PK AF Pandey, PC Singh, S Upadhyay, B Weetall, HH Chen, PK TI Reversal in the kinetics of the M state decay of D96N bacteriorhodopsin: Probing of enzyme catalyzed reactions SO SENSORS AND ACTUATORS B-CHEMICAL LA English DT Article; Proceedings Paper CT Proceedings of the 6th International Meeting on Chemical Sensors CY JUL 22-25, 1996 CL GAITHERSBURG, MD DE M state decay; kinetics; D96N bacteriorhodopsin ID SOL-GEL GLASS; MEMBRANE-PROTEIN; PROTON-TRANSFER; M-INTERMEDIATE; PH-DEPENDENCE; SCHIFF-BASE; PHOTOCYCLE; PHOTOREACTION; DEPROTONATION; PATHWAYS AB The kinetics of M state decay of the D96N bacteriorhodopsin (BR) in the presence of (i) ammonium ion and (ii) an aromatic amine is reported. The M state decay rate becomes faster in the presence of ammonium salt with a concomitant decrease in absorbance maxima at 410 nm. In the presence of an aromatic amine, a slower M state decay rate with an increase in absorbance maxima at 410 nm is observed. The variation in the kinetics of M-state decay is due to the change in the lifetime of the M-state associated with the conversion of M-intermediate to trans-BR. The decay rate of the M-state has also been found to be greatly affected in the presence of enzymatic reactions resulting in the formation of either an acid or a base. Three enzymatic reaction systems, urease, acetylcholinesterase and penicillinase, have been used to study the kinetics of M state decay of D96N bacteriorhodopsin, The kinetic data are found to be dependent on the concentrations of the respective enzyme's substrate. Results of the studies using urea, acetylcholine and penicillin are reported. The enzymes were also immobilized together with D96N bacteriorhodopsin in sol-gel glass to develop a biosensor for the analysis of urea, acetylcholine and penicillin. C1 NIST,DIV BIOTECHNOL,GAITHERSBURG,MD 20899. GEORGETOWN UNIV,DEPT BIOL,WASHINGTON,DC 20057. RP Pandey, PC (reprint author), BANARAS HINDU UNIV,DEPT CHEM,VARANASI 221005,UTTAR PRADESH,INDIA. NR 28 TC 6 Z9 6 U1 0 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-4005 J9 SENSOR ACTUAT B-CHEM JI Sens. Actuator B-Chem. PD OCT PY 1996 VL 36 IS 1-3 BP 470 EP 474 DI 10.1016/S0925-4005(97)80115-3 PG 5 WC Chemistry, Analytical; Electrochemistry; Instruments & Instrumentation SC Chemistry; Electrochemistry; Instruments & Instrumentation GA WJ775 UT WOS:A1996WJ77500037 ER PT J AU McCurley, MF Bayer, GJ Glazier, SA AF McCurley, MF Bayer, GJ Glazier, SA TI A fluorescence assay for dissolved oxygen using sol-gel encapsulated myoglobin and an analogy to the inner filter effect SO SENSORS AND ACTUATORS B-CHEMICAL LA English DT Article; Proceedings Paper CT Proceedings of the 6th International Meeting on Chemical Sensors CY JUL 22-25, 1996 CL GAITHERSBURG, MD DE sol-gel glasses; myoglobin; fluorescence; dissolved oxygen; inner filter effect AB In this study, we were interested in how the limit of detection for dissolved oxygen (DO) measurements in water would be affected when absorbances were translated into fluorescence intensities of a dye through a process analogous to the inner filter effect. The DO measurements were made through the oxygenation of deoxy-myoglobin trapped in a sol-gel matrix. First, the encapsulated myoglobin is reduced from met-myoglobin to deoxy-myoglobin by bathing the gel in a dithionite solution. Then, the gel is introduced to the sample of dissolved oxygen in water. Dissolved oxygen reacts with deoxy-myoglobin to give oxy-myoglobin. The observed spectroscopic changes are indicative of dissolved oxygen in water. In our system, the fluorescent dye, brilliant sulfaflavine, absorbs light at 430 nm and emits radiation at 520 nm. The excitation light for the dye is passed through the myoglobin-containing gel. The emission of the fluorescent dye changes as the absorbance of the myoglobin at 430 nm changes in response to dissolved oxygen in water. Theoretically, the change in fluorescence should be larger than the corresponding change in absorbance. From this work, it was concluded that the detection limit for dissolved air measurements could be enhanced through fluorescence provided that the sol-gels had long enough exposure to the water samples. RP McCurley, MF (reprint author), NIST,BIOMOL MAT GRP,GAITHERSBURG,MD 20899, USA. NR 10 TC 3 Z9 3 U1 1 U2 2 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-4005 J9 SENSOR ACTUAT B-CHEM JI Sens. Actuator B-Chem. PD OCT PY 1996 VL 36 IS 1-3 BP 491 EP 496 DI 10.1016/S0925-4005(97)80118-9 PG 6 WC Chemistry, Analytical; Electrochemistry; Instruments & Instrumentation SC Chemistry; Electrochemistry; Instruments & Instrumentation GA WJ775 UT WOS:A1996WJ77500040 ER PT J AU Tison, SA AF Tison, SA TI Accurate flow measurement in vacuum processing SO SOLID STATE TECHNOLOGY LA English DT Article AB Many semiconductor processes use the thermal mass flowmeter, or mass flow controller (MFC), to deliver stable and known flows of gas to the processing chamber. This meter senses the flow by measuring thermal transfer between a heated tube wall and the gas stream. MFCs operate over a wide flow range--0.04 mol/sec to 7.4 x 10(-8) mol/sec dagger (5 x 10(4) to 0.1 sccm)--and are suitable for use with most gases, including corrosives, routinely used in the semiconductor industry. Recent requirements for better process control demand improved accuracy, higher reliability, and measurement and control at lower flows. RP Tison, SA (reprint author), NATL INST STAND & TECHNOL,BLDG 220,ROOM A55,GAITHERSBURG,MD 20899, USA. NR 11 TC 1 Z9 1 U1 0 U2 0 PU PENNWELL PUBL CO SOLID STATE TECHNOLOGY OFFICE PI NASHUA PA TEN TARA BLVD 5TH FLOOR, NASHUA, NH 03062-2801 SN 0038-111X J9 SOLID STATE TECHNOL JI Solid State Technol. PD OCT PY 1996 VL 39 IS 10 BP 73 EP & PG 6 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA VL206 UT WOS:A1996VL20600015 ER PT J AU Lallement, R Linsky, JL Lequeux, J Baranov, VB AF Lallement, R Linsky, JL Lequeux, J Baranov, VB TI Physical and chemical characteristics of the ISM inside and outside the heliosphere SO SPACE SCIENCE REVIEWS LA English DT Review ID LOCAL INTERSTELLAR-MEDIUM; HST-GHRS OBSERVATIONS; SOLAR-SYSTEM; SIRIUS-A; HYDROGEN; CLOUD; SPECTROSCOPY; INTERFACE; DEUTERIUM; CAPELLA AB This paper summarizes some of the discussions of working group 8-9 during the ISSI Conference on ''The Heliosphere in the Local Interstellar Medium''. Because the subject of these working groups has become significantly broader during the last ten years, we have selected three topics for which recent observations have modified and improved our knowledge of the heliosphere and the surrounding interstellar medium. These topics are the number densities and ISM ionization states of hydrogen and helium, the newly discovered hot gas from the ''H wall'' seen in absorption, and the comparison between ISM and heliospheric minor element abundances. Papers from this volume in which more details on these topics can be found are quoted throughout the report. C1 UNIV COLORADO, JOINT INST LAB ASTROPHYS, BOULDER, CO 80309 USA. NATL INST STAND & TECHNOL, BOULDER, CO 80309 USA. OBSERV PARIS, F-75014 PARIS, FRANCE. RUSSIAN ACAD SCI, INST PROBLEMS MECH, MOSCOW 117526, RUSSIA. RP CNRS, SERV AERON, BP 3, F-91371 VERRIERES LE BUISSON, FRANCE. NR 29 TC 7 Z9 7 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-6308 EI 1572-9672 J9 SPACE SCI REV JI Space Sci. Rev. PD OCT PY 1996 VL 78 IS 1-2 BP 299 EP 304 DI 10.1007/BF00170816 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VW650 UT WOS:A1996VW65000033 ER PT J AU Xiong, X Hutchinson, JMR Hess, KR Fassett, JD Lucatorto, TB AF Xiong, X Hutchinson, JMR Hess, KR Fassett, JD Lucatorto, TB TI A novel approach to resonance ionization mass spectrometry employing a glow discharge atom source SO SPECTROCHIMICA ACTA PART B-ATOMIC SPECTROSCOPY LA English DT Article DE atomic counting; glow discharge; laser ionization; mass spectrometry; radioactivity; resonance ionization ID TRACE-ELEMENTS AB This paper reports on preliminary efforts to design and implement a novel combination of a laser, a glow discharge atom source, and a magnetic sector mass spectrometer to be used for resonance ionization of the discharge sputtered material. In this experimental design, a glow discharge source has been constructed and interfaced to a magnetic sector mass spectrometer. The laser is then focused in a spatial region between the exit orifice of the glow discharge source and the extraction optics of the mass spectrometer. Laser interaction in the low pressure region external to the discharge plasma is believed to provide several advantages for resonance ionization over previous designs in which the laser was allowed to interact within the discharge plasma. Preliminary results show resonance ionization to improve the isotopic ratios of iron in an aluminum matrix (iron-58 content of 396 mu g g(-1)) relative to those observed directly from the glow discharge which are subject to isobaric overlaps. C1 US DEPT COMMERCE,TECHNOL ADM,NATL INST STAND & TECHNOL,PHYS LAB,GAITHERSBURG,MD 20899. FRANKLIN & MARSHALL COLL,DEPT CHEM,LANCASTER,PA 17604. NR 22 TC 3 Z9 3 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0584-8547 J9 SPECTROCHIM ACTA B JI Spectroc. Acta Pt. B-Atom. Spectr. PD OCT PY 1996 VL 51 IS 12 BP 1463 EP 1472 DI 10.1016/0584-8547(96)01540-6 PG 10 WC Spectroscopy SC Spectroscopy GA VT194 UT WOS:A1996VT19400004 ER PT J AU Gaggiotti, OE AF Gaggiotti, OE TI Population genetic models of source-sink metapopulations SO THEORETICAL POPULATION BIOLOGY LA English DT Article ID LOCAL EXTINCTION; DYNAMICS; SIZE; RECOLONIZATION; DISPERSAL; FREQUENT; NUMBER; SITES; FLOW AB The present study investigates the effect that different patterns of migration have on the genetic structure of source-sink metapopulations specifically modelling the dynamics of local populations. The model assumes a metapopulation consisting of a single source and s different sink populations and considers the expected number of nucleotide differences between two genes drawn at random from the source-sink metapopulation. The results show that a collection of interconnected sinks can maintain a substantial fraction of the genetic variability observed in the source population, particularly where migration from the source is continuous over time. The degree of genetic differentiation among the sinks might be large, especially if migra tion from the source is stochastic. Genetic differentiation is small when extinctions are frequent (because most of the sink populations are composed of recent migrants from the source) or extremely rare (because of the increased effect of migration among sinks), being maximized when the frequency of extinctions is between these two extremes. (C) 1996 Academic Press. Inc. C1 NATL MARINE FISHERIES SERV, SW FISHERIES SCI CTR, LA JOLLA, CA 92038 USA. RI Gaggiotti, Oscar/G-2459-2010 OI Gaggiotti, Oscar/0000-0003-1827-1493 NR 29 TC 42 Z9 43 U1 0 U2 8 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0040-5809 EI 1096-0325 J9 THEOR POPUL BIOL JI Theor. Popul. Biol. PD OCT PY 1996 VL 50 IS 2 BP 178 EP 208 DI 10.1006/tpbi.1996.0028 PG 31 WC Ecology; Evolutionary Biology; Genetics & Heredity SC Environmental Sciences & Ecology; Evolutionary Biology; Genetics & Heredity GA VN609 UT WOS:A1996VN60900004 ER PT J AU Abramowitz, S AF Abramowitz, S TI Towards inexpensive DNA diagnostics SO TRENDS IN BIOTECHNOLOGY LA English DT Review ID CAPILLARY ARRAY ELECTROPHORESIS; HIGH-SPEED; MASS-SPECTROMETRY; OLIGONUCLEOTIDE ARRAYS; SEQUENCING REACTIONS; NUCLEIC-ACIDS; POLYMERASE; CHIPS; MICROCHIP AB Methodologies to obtain DNA sequence information efficiently and accurately will provide the basis for a broad spectrum of economical products and applications to a variety of industrial sectors, in addition to healthcare. Such technologies will build upon the evolving molecular biology and instrumentation base that is serving a specific research market. This will require the efficient integration of technical advances in microchemistry, micromachining, separation technologies, detection systems, microelectronics and information technology, and will involve the expertise of engineers, physicists, chemists, mathematicians, computer scientists and molecular biologists. The biotechnology, microelectronics, software, instrumentation, pharmaceutical and fine chemical industries will be vital to this development. RP Abramowitz, S (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 38 TC 23 Z9 22 U1 0 U2 1 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0167-7799 J9 TRENDS BIOTECHNOL JI Trends Biotechnol. PD OCT PY 1996 VL 14 IS 10 BP 397 EP 401 DI 10.1016/0167-7799(96)10051-2 PG 5 WC Biotechnology & Applied Microbiology SC Biotechnology & Applied Microbiology GA VN103 UT WOS:A1996VN10300007 PM 8987638 ER PT J AU Gates, RS Hsu, SM AF Gates, RS Hsu, SM TI Silicon nitride boundary lubrication: Effect of phosphorus-containing organic compounds SO TRIBOLOGY TRANSACTIONS LA English DT Article DE boundary lubrication; ceramics; friction; phosphate esters; surface films coatings; wear and failure ID ADDITIVES; OIL AB The boundary lubricating characteristics of phosphorus-containing compounds on silicon nitride were studied using a ball-on-three-flat wear tester. ?Xe compounds were tested at I % by weight in a pure paraffin oil under a mean pressure of about 2 GPa. The compounds are effective in reducing wear. Continuous surface films were observed in and around the wear scars for most of the phosphorus compounds. These films are complex mixtures containing phosphorus and silicon. A detailed study on a zinc dithiophosphate (ZDP) surface film revealed high concentrations of zinc and phosphorus, but very little sulfur. This is in direct contrast to surface analysis results on steel systems in which sulfur-containing species are found on the worn surface. This suggests different chemical reaction, pathways for phosphorus compounds on steel and silicon nitride surfaces. RP Gates, RS (reprint author), NIST,DIV CERAM,GAITHERSBURG,MD 20899, USA. NR 10 TC 9 Z9 9 U1 0 U2 3 PU SOC TRIBOLOGISTS & LUBRICATION ENGINEERS PI PARK RIDGE PA 838 BUSSE HIGHWAY, PARK RIDGE, IL 60068 SN 0569-8197 J9 TRIBOL T JI Tribol. Trans. PD OCT PY 1996 VL 39 IS 4 BP 795 EP 802 DI 10.1080/10402009608983597 PG 8 WC Engineering, Mechanical SC Engineering GA VP652 UT WOS:A1996VP65200006 ER PT J AU Tatarskii, VV Tatarskii, VI AF Tatarskii, VV Tatarskii, VI TI Non-Gaussian statistical model of the ocean surface for wave-scattering theories SO WAVES IN RANDOM MEDIA LA English DT Article ID PROBABILITY-DISTRIBUTION AB Usually the model of a Gaussian, statistically homogeneous rough surface is used in the theory of rough-surface scattering, not because of physical reasons, but because it is difficult to use a more realistic model. In this paper we apply a version of the theory of non-Gaussian random functions (Tatarskii V I 1995 Waves Random Media 5 243-52) for the ocean surface. We develop the method of obtaining all necessary functional and numerical parameters for the complete statistical description of the random surface of the type described by Tatarskii and having the following properties: 1. The spectrum of the surface describes the range of surface wavelength from fully developed wind waves to the gravity-capillary region (Apel J R 1994 J. Geophys. Res./Oceans 99 16.269-91). 2. The probability distribution function (PDF) of the surface elevations in any single point is non-Gaussian and corresponds to the experimental data obtained by Huang and Long (Huang N E and Long S R 1980 J. Fluid Mech. 101 179-200). 3. The explicit analytical formulae in terms of model parameters can be derived for any mean value, appearing in the wave-scattering theory. With these given statistical parameters, we present an example of the surface, generated by a Monte Carlo simulation. The method derived easily allows us to incorporate new experimental data if they appear. C1 NOAA,ENVIRONM TECHNOL LAB,BOULDER,CO 80303. RP Tatarskii, VV (reprint author), UNIV COLORADO,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80303, USA. NR 17 TC 14 Z9 16 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0959-7174 J9 WAVE RANDOM MEDIA JI Waves Random Media PD OCT PY 1996 VL 6 IS 4 BP 419 EP 435 DI 10.1088/0959-7174/6/4/006 PG 17 WC Physics, Multidisciplinary SC Physics GA VT263 UT WOS:A1996VT26300006 ER PT J AU DeGroot, DC Rudman, DA Zhang, K Ma, QY Kato, H Jaeger, NAF AF DeGroot, DC Rudman, DA Zhang, K Ma, QY Kato, H Jaeger, NAF TI Planar microwave devices fabricated by ion-implantation patterning of high-temperature superconductors SO APPLIED PHYSICS LETTERS LA English DT Article ID FILMS AB We have applied ion-implantation inhibit patterning as a new method of fabricating low-loss microwave transmission lines in high-temperature superconductor thin films. To determine the effectiveness of this technique, we-fabricated coplanar waveguide transmission lines in YBa2Cu3O7-delta thin films that had been deposited on LaAlO3 substrates using pulsed laser deposition. Microwave characterizations of these lines are compared to a reference line fabricated with conventional ion milling. At 76 K and 12 GHz, the attenuation constants of the ion-implanted transmission lines are approximated 0.02 dB/mm, and the overall loss response is indistinguishable from that of the ion-milled device. (C) 1996 American Institute of Physics. C1 COLUMBIA UNIV,DEPT ELECT ENGN,NEW YORK,NY 10027. UNIV BRITISH COLUMBIA,DEPT ELECT ENGN,VANCOUVER,BC V6T 1Z4,CANADA. RP DeGroot, DC (reprint author), NATL INST STAND & TECHNOL,DIV ELECTROMAGNET FIELDS,325 BROADWAY,BOULDER,CO 80303, USA. NR 12 TC 10 Z9 10 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD SEP 30 PY 1996 VL 69 IS 14 BP 2119 EP 2121 DI 10.1063/1.116899 PG 3 WC Physics, Applied SC Physics GA VJ783 UT WOS:A1996VJ78300044 ER PT J AU Berkowitz, SJ Hirahara, AS Char, K Grossman, EN AF Berkowitz, SJ Hirahara, AS Char, K Grossman, EN TI Low noise high-temperature superconducting bolometers for infrared imaging SO APPLIED PHYSICS LETTERS LA English DT Article ID AIR-BRIDGE; SILICON AB High-temperature superconducting bolometric infrared detectors offer the promise of matching the sensitivity of HgCdTe detectors, but with an extended detection range to longer wavelengths (lambda >15 mu m). We fabricated high-temperature superconducting bolometers using an all-epitaxial micromachining technology based upon a YBa2Cu3Ox thin film on a yttria-stabilized zirconia free-standing 50X50 mu m(2) membrane supported on a LaAlO3 substrate. This structure has simultaneously a low thermal conductance and a low heat capacity. Using this technology, we have made array-compatible pixels for infrared camera applications with optical noise equivalent powers as low as 6.3 X 10(-13) W/root Hz at 32 Hz. Over more than 1 octave of frequency range, these bolometers are limited by fundamental (chiefly phonon) noise sources rather than excess him noise. (C) 1996 American Institute of Physics. C1 NIST,BOULDER,CO 80303. RP Berkowitz, SJ (reprint author), CONDUCTUS INC,SUNNYVALE,CA 94086, USA. NR 7 TC 35 Z9 35 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD SEP 30 PY 1996 VL 69 IS 14 BP 2125 EP 2127 DI 10.1063/1.117174 PG 3 WC Physics, Applied SC Physics GA VJ783 UT WOS:A1996VJ78300046 ER PT J AU Han, CC AF Han, CC TI Quasielastic scattering by dilute polymer solutions - Comment SO JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS LA English DT Editorial Material ID DYNAMIC LIGHT-SCATTERING; RANDOM-PHASE-APPROXIMATION; BLOCK-COPOLYMER SOLUTIONS; 1ST CUMULANT; MIXTURES; REGION; CHAINS RP Han, CC (reprint author), NATL INST STAND & TECHNOL,DIV POLYMER,GAITHERSBURG,MD 20899, USA. NR 28 TC 1 Z9 1 U1 0 U2 1 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0887-6266 J9 J POLYM SCI POL PHYS JI J. Polym. Sci. Pt. B-Polym. Phys. PD SEP 30 PY 1996 VL 34 IS 13 BP 2113 EP 2115 PG 3 WC Polymer Science SC Polymer Science GA VE107 UT WOS:A1996VE10700003 ER PT J AU Was, GS Foecke, T AF Was, GS Foecke, T TI Deformation and fracture in microlaminates SO THIN SOLID FILMS LA English DT Review DE deformation; fracture; microlaminates ID POLYCRYSTALLINE THIN-FILMS; METAL-CERAMIC INTERFACES; HALL-PETCH RELATION; MECHANICAL-PROPERTIES; MULTILAYERED MATERIALS; LAYERED MATERIALS; NANOCRYSTALLINE MATERIALS; STRESS REDISTRIBUTION; ENHANCED HARDNESS; STRAINED-LAYER AB The utility of microlaminates in engineering applications depends ultimately on their strength and toughness. While the properties of monolithic films and coatings can be controlled through crystal structure and microstructure, the properties of microlaminates are a sensitive function of the interfaces, It is the large number of interfaces in a microlaminate that determines the unique behavior of this special type of composite. This review begins with a property-based definition of a microlaminate. The mechanisms by which microlaminates deform plastically are reviewed and evaluated in the context of data on metal-metal, metal-intermetallic, metal-ceramic and ceramic-ceramic systems. It is evident that in addition to layer geometry, the layer microstructure plays a major role in determining the operative deformation mechanism. The fracture processes in a microlaminate are examined in the context of the layer strength, microstructure, defects and crack-tip-dislocation processes. High toughnesses in microlaminate materials can be attained through a combination of mechanisms, and their effectiveness depends critically on the ability to affect the magnitude and shape of the stress field at the tip of the crack. The study of deformation and fracture in microlaminates is still a relatively young field in materials science. However, while our understanding of these processes is still quite incomplete, it is improving rapidly with advances in experiment, theory and modeling capability. C1 UNIV MICHIGAN,DEPT NUCL ENGN & RADIOL SCI,ANN ARBOR,MI 48109. NATL INST STAND & TECHNOL,DIV MET,GAITHERSBURG,MD 20899. RP Was, GS (reprint author), UNIV MICHIGAN,DEPT MAT SCI & ENGN,ANN ARBOR,MI 48109, USA. NR 113 TC 200 Z9 215 U1 7 U2 78 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD SEP 30 PY 1996 VL 286 IS 1-2 BP 1 EP 31 DI 10.1016/S0040-6090(96)08905-5 PG 31 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA VY061 UT WOS:A1996VY06100001 ER PT J AU Reid, GC Gage, KS AF Reid, GC Gage, KS TI The tropical tropopause over the western Pacific: Wave driving, convection, and the annual cycle SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID STRATOSPHERE-TROPOSPHERE EXCHANGE; GENERAL-CIRCULATION MODEL; DOWNWARD CONTROL; WATER-VAPOR; TEMPERATURE; MONSOON; HEIGHT; MASS; STEP; AIR AB The annual cycles in height and temperature of the tropopause over the tropical western Pacific island of Truk (7.5 degrees N, 151.8 degrees E) are derived for the period 1980-1988 from daily radiosonde profiles. Earlier work has shown that tropopause properties are fairly uniform over large areas of the tropics, so that conclusions drawn from the Truk observations can be taken as representative of the western Pacific warm pool region, and can be applied with caution to wider regions of the tropics. The relative roles of tropical convection and extratropical wave driving in determining the tropopause properties are discussed, and it is suggested that the chief role of wave driving is to lower the temperature in the uppermost part of the troposphere during the northern winter months, causing a decrease in local stability, and allowing penetrative overshooting of convective turrets to take place more readily than during the rest of the year. As the winter progresses, the overshooting convective turrets create widespread cirrus anvils, incorporating stratospheric air with a high potential temperature, and establishing a new higher tropopause. Anomalously high tropopause potential temperatures during the northern spring months are tentatively attributed to the combined wave-driving action of the two hemispheres, as wave activity increases with the approach of winter in the southern hemisphere, but still remains at a high level during northern spring. The day-to-day variability in tropopause height and temperature is discussed, and is shown to have implications for troposphere-stratosphere exchange. The use of monthly mean tropopause temperatures to calculate the saturation vapor pressure of water entering the stratosphere may give misleading results, since injection is likely to take place primarily in association with the transient rises in tropopause height and decreases in temperature that occur more or less randomly from day to day, while the monthly means also include the drops in height and increases in temperature that do not represent injections into the stratosphere. C1 UNIV COLORADO, COOPERAT INST RES ENVIRONM SCI, BOULDER, CO 80309 USA. RP Reid, GC (reprint author), NOAA, AERON LAB, 325 BROADWAY, BOULDER, CO 80303 USA. NR 34 TC 88 Z9 90 U1 0 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP 27 PY 1996 VL 101 IS D16 BP 21233 EP 21241 DI 10.1029/96JD01622 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VK041 UT WOS:A1996VK04100005 ER PT J AU Kondragunta, CR Gruber, A AF Kondragunta, CR Gruber, A TI Seasonal and annual variability of the diurnal cycle of clouds SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID ISCCP; MODEL; CIRCULATION; CONVECTION; RADIATION; PACIFIC; PRECIPITATION; CLOUDINESS; RADIANCES; ATLANTIC AB Eight years of cloudiness data from the International Satellite Cloud Climatology Project (ISCCP) were analyzed to study the diurnal variation and its annual variation. An empirical orthogonal function (EOF) analysis technique was used to analyze the ISCCP C-2 monthly hourly data. Results show that most of the diurnal variation is explained by the first two dominant EOF modes, which explain the diurnal cycle of-clouds. On the basis of this analysis, two modes of diurnal cycle of clouds are defined. Mode 1 as defined by the first EOF indicates that cloudiness maximum occurs at 0500 or 1500 local solar time (LST); Mode 2 as defined by the second EOF indicates that cloudiness maximum occurs at 1000 or 2000 LST. In a broad sense, Mode 1 explains the diurnal cycle of low-level cloudiness, and Mode 2 explains the diurnal variation of high-level cloudiness. Mode 1 explains 58.5% of the normalized variance, and Mode 2 explains 25% of the normalized variance. Both modes of the diurnal cycle show annual variation. The Mode 1 annual variation is large along the western boundary currents over the oceanic regions and moist convective regions over the continents. Interestingly, this annual variation of the diurnal cycle of cloudiness bears some relationship with the annual variation of the surface temperature. This relationship is such that the cloudiness is maximum in the early morning when the annual surface temperature is at its minimum and in the afternoon when the annual surface temperature is at its maximum. C1 NOAA, NATL ENVIRONM SATELLITE DATA & INFORMAT SERV, OFF RES & APPLICAT, WASHINGTON, DC 20333 USA. RP Kondragunta, CR (reprint author), UNIV MARYLAND, DEPT METEOROL, COOPERAT INST CLIMATE STUDIES, 2213 SPACE SCI BLDG, COLLEGE PK, MD 20742 USA. NR 33 TC 8 Z9 8 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP 27 PY 1996 VL 101 IS D16 BP 21377 EP 21390 DI 10.1029/96JD01544 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VK041 UT WOS:A1996VK04100018 ER PT J AU Feingold, G Kreidenweis, SM Stevens, B Cotton, WR AF Feingold, G Kreidenweis, SM Stevens, B Cotton, WR TI Numerical simulations of stratocumulus processing of cloud condensation nuclei through collision-coalescence SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID MARINE BOUNDARY-LAYER; STRATIFORM CLOUD; AEROSOLS; MICROPHYSICS; SULFUR; MODEL AB The role of drop collision-coalescence as a means of reducing drop number concentrations, and hence cloud condensation nucleus (CCN) concentrations as these are cycled in the stratocumulus-capped marine boundary layer, is investigated. We focus on the impact of this process on the mass-mean size of CCN in the absence of wet deposition, and compare this mechanism with size changes resulting from mass addition through aqueous chemistry. The modeling framework is a two-dimensional eddy-resolving model that includes explicit treatment of aerosol and drop spectra, as well as the solute transfer between drop size bins. The microphysical processes considered are droplet activation, condensation/evaporation, collision-coalescence, sedimentation and regeneration of particles following complete evaporation. It is shown that for a case exhibiting negligible-wet deposition, collision-coalescence can significantly reduce drop concentrations (22% h(-1)) resulting in a measurable increase In particle mass-mean radius of about 7% h(-1). In order to extend the validity of these results, trajectory analyses of parcel in-cloud residence times have been used together with box model calculations of collision-coalescence to explore the parameters affecting processing through collision-coalescence. This trajectory information is also used to deduce the extent of in-cloud conversion of SO2 to sulfate. Comparisons show that the two mechanisms may produce comparable rates of increase in the mean particle size under certain conditions. Results for remote marine conditions suggest that aqueous phase chemistry may have a greater impact at lower cloud liquid-water contents, whereas collision-coalescence may dominate at higher liquid-water contents, or for broader drop spectra. C1 COLORADO STATE UNIV, DEPT ATMOSPHER SCI, FT COLLINS, CO 80523 USA. RP Feingold, G (reprint author), COLORADO STATE UNIV, NOAA, COOPERAT INST RES ATMOSPHERE, 325 BROADWAY, BOULDER, CO 80303 USA. RI Stevens, Bjorn/A-1757-2013; Feingold, Graham/B-6152-2009; Kreidenweis, Sonia/E-5993-2011 OI Stevens, Bjorn/0000-0003-3795-0475; Kreidenweis, Sonia/0000-0002-2561-2914 NR 37 TC 63 Z9 64 U1 0 U2 14 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP 27 PY 1996 VL 101 IS D16 BP 21391 EP 21402 DI 10.1029/96JD01552 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VK041 UT WOS:A1996VK04100019 ER PT J AU Alfassi, ZB Khaikin, GI Johnson, RD Neta, P AF Alfassi, ZB Khaikin, GI Johnson, RD Neta, P TI Formylmethyl and formylmethylperoxyl radicals and their chlorinated derivatives. Formation and reactions in irradiated aqueous solutions SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID PULSE-RADIOLYSIS; RATE CONSTANTS; HYDROXYL RADICALS; PEROXYL RADICALS; 2-ALKANONYL RADICALS; ELECTRON-TRANSFER; ORGANIC-COMPOUNDS; REACTIVITY; ACID; OH AB The formylmethyl radical, (CH2CHO)-C-., is known to act as an oxidant. For comparison, the chlorinated analogues, (CCl2CHO)-C-. and (CCl2CClO)-C-., were produced in irradiated aqueous solutions and their oxidation reactions studied. The radicals were produced by reaction of (OH)-O-. with trichloroethanol (CCl3CH2OH) or tetrachloroethylene (CCl2=CCl2) followed by elimination of HCl. CCl3CH2OH reacts with OH radicals, with rate constants of 1.5 x 10(8) L mol(-1) s(-1) at pH 6.6 and 1.9 x 10(9) L mol(-1) s(-1) at pH 11.4, at which the compound is partially ionized (pK(a)=12.2). These reactions take place by hydrogen abstraction to yield CCl3CHOH or CCl3CHO-, which rapidly eliminate HCl or Cl- to form the (CCl2CHO)-C-. radical. Parallel experiments with trifluoroethanol indicated formation of the CF3CHOH radical which does not eliminate HF. This radical reduces methylviologen (MV(2+), 1,1'-dimethyl-4,4'-bipyridinium dication) slowly in acidic solutions but very rapidly in alkaline solutions. From the pH effect on the rate constant, a pK(a) value of 6.0 was determined for the acid dissociation of CF3CHOH into CF3CHO-. The (CCl2CHO)-C-. radical is an oxidizing species, which reacts with ascorbate, ABTS(2-) [2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonate ion)], and phenolate ions somewhat more slowly than (CH2CHO)-C-.. Tn contrast, (CCl2CClO)-C-. reacts with the same compounds much more rapidly than (CH2CHO)-C-.. All three formylmethyl radicals react with O-2 to yield peroxyl radicals, The peroxyl radicals derived from the chlorinated formylmethyl are stronger oxidants than their parent species, but the peroxyl radical derived from the unchlorinated formylmethyl is a weaker oxidant than its parent species. Peroxyl radicals were also produced by the reaction of e(aq)(-) with CCl3CH2OH and with chloral hydrate in aerated solutions. These radicals, (OOCCl2CH2OH)-O-. and (OOCCl2CH)-O-.(OH)(2), are highly reactive oxidants. C1 NIST,PHYS & CHEM PROPERTIES DIV,GAITHERSBURG,MD 20899. BEN GURION UNIV NEGEV,IL-84105 BEER SHEVA,ISRAEL. NR 32 TC 5 Z9 6 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD SEP 26 PY 1996 VL 100 IS 39 BP 15961 EP 15967 DI 10.1021/jp961628s PG 7 WC Chemistry, Physical SC Chemistry GA VK046 UT WOS:A1996VK04600048 ER PT J AU Irwin, KD Hilton, GC Wollman, DA Martinis, JM AF Irwin, KD Hilton, GC Wollman, DA Martinis, JM TI X-ray detection using a superconducting transition-edge sensor microcalorimeter with electrothermal feedback SO APPLIED PHYSICS LETTERS LA English DT Article ID RESOLUTION AB We have developed a new type of x-ray detector based on a superconducting transition-edge thermometer operated near 100 mK. A superconducting quantum interference device is used to measure the current through the thermometer, and negative electrothermal feedback is used to improve the energy resolution and shorten the thermal time constant. We have used a detector mounted on a scanning electron microscope to measure the energy of titanium K alpha (4.5 keV) fluorescence x rays with a resolution better than 14 eV full width at half-maximum. Using two other devices, we have measured an energy resolution for Joule heat pulses of 2.6 eV at 1 keV and 0.2 eV at 4 eV, the best reported for any calorimeter. An electrical noise equivalent power of 3 X 10(-18) W/root Hz was also measured, suggesting the use of these detectors as infrared bolometers. RP Irwin, KD (reprint author), NATL INST STAND & TECHNOL,325 BROADWAY,BOULDER,CO 80303, USA. NR 14 TC 152 Z9 152 U1 2 U2 10 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD SEP 23 PY 1996 VL 69 IS 13 BP 1945 EP 1947 DI 10.1063/1.117630 PG 3 WC Physics, Applied SC Physics GA VH795 UT WOS:A1996VH79500042 ER PT J AU Kunkel, G Ono, RH AF Kunkel, G Ono, RH TI Mutual phase-locking of ten YBa2Cu3O7 step-edge Josephson junctions up to 45 K SO APPLIED PHYSICS LETTERS LA English DT Article ID SUPERCONDUCTING LOOP; ARRAY AB We have developed a microwave circuit using ten parallel-biased high-temperature superconductor Josephson junctions to demonstrate phase-locking for applications such as oscillators, mixers, and detectors. The basic cell consists of two Josephson junctions enclosed in a microstrip resonator, which provides voltage-locking and low dynamic resistance in the current-voltage characteristic. Partial synchronization of the ten junctions was observed up to 45 K and up to 1 THz. The implications of this design for power and radiation Linewidth will be discussed. (C) 1996 American Institute of Physics. C1 NATL INST STAND & TECHNOL, DIV ELECTROMAGNET TECHNOL, BOULDER, CO 80303 USA. RP Kunkel, G (reprint author), FORSCHUNGSZENTRUM JULICH, FORSCHUNGSZENTRUM, INST SCHICHT & IONENTECH, POSTFACH 1913, D-52425 JULICH, GERMANY. NR 14 TC 9 Z9 10 U1 0 U2 4 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD SEP 23 PY 1996 VL 69 IS 13 BP 1960 EP 1962 DI 10.1063/1.117635 PG 3 WC Physics, Applied SC Physics GA VH795 UT WOS:A1996VH79500047 ER PT J AU Ashfold, MNR Western, CM Hudgens, JW Johnson, RD AF Ashfold, MNR Western, CM Hudgens, JW Johnson, RD TI Characterisation of the (E)over-tilde'(1)A'(1) Rydberg state of ammonia by resonance enhanced multiphoton ionisation spectroscopy SO CHEMICAL PHYSICS LETTERS LA English DT Article ID VACUUM ULTRAVIOLET ENERGIES; EXPANSION-COOLED AMMONIA; SUB-DOPPLER SPECTROSCOPY; OPTICAL DOUBLE-RESONANCE; MULTI-PHOTON IONIZATION; PHOTOELECTRON-SPECTROSCOPY; MPI SPECTROSCOPY; NH3; ND3; DYNAMICS AB Progression of bands associated with the nu(2) (bending) vibrational mode of the (E) over tilde'(1)A'(1) (4pa ''(2) <-- 3a(1)) Rydberg states of both NH3 and ND3 have been observed as two-photon resonances in the multiphoton ionisation spectrum of these two isotopomers at excitation wavelengths in the range 275-248 nm. Band contour analysis yields excited state spectroscopic parameters and some insight into the predissociation behaviour of these levels, all of which show many parallels with previous knowledge concerning the (C) over tilde'(1)A'(1) Rydberg state of ammonia (arising from the corresponding 3pa ''(2) <-- 3a(1) orbital promotion). C1 NATL INST STAND & TECHNOL, CHEM SCI & TECHNOL LAB, PHYS & CHEM PROPERTIES DIV, GAITHERSBURG, MD 20899 USA. RP Ashfold, MNR (reprint author), UNIV BRISTOL, SCH CHEM, CANTOCKS CLOSE, BRISTOL BS8 1TS, AVON, ENGLAND. OI Western, Colin/0000-0002-8336-1690; ashfold, michael/0000-0001-5762-7048 NR 34 TC 10 Z9 10 U1 1 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 EI 1873-4448 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD SEP 20 PY 1996 VL 260 IS 1-2 BP 27 EP 33 DI 10.1016/0009-2614(96)00803-2 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VH100 UT WOS:A1996VH10000005 ER PT J AU Rao, CRN Chen, JH AF Rao, CRN Chen, JH TI Post-launch calibration of the visible and near-infrared channels of the advanced very high resolution radiometer on the NOAA-14 spacecraft SO INTERNATIONAL JOURNAL OF REMOTE SENSING LA English DT Article ID AVHRR AB The post-launch calibration of the visible (channel 1:approximate to 0.58-0.68 mu m) and near-infrared (channel 2: approximate to 0.72-1.1 mu m) channels of the Advanced Very High Resolution Radiometer (AVHRR) on the NOAA-14 spacecraft is described. The southeastern part of the Libyan desert (21-23 degrees N latitude; 28-29 degrees E longitude) is used as a radiometrically stable calibration target to determine the 'slope'-the inverse of the gain-of the AVHRR, expressed in units of W (m(-2) sr(-1) mu m(-1) count(-1)), in the two channels in the course of 1995. The variation of the 'slope' with time during 1995 indicates that channel 1 has degraded at the annual rate of 7.7 per cent; and channel 2 at the rate of 10.5 per cent. Comparison of the AVHRR 'slopes' immediately after launch of NOAA-14 with the results of pre-launch calibration performed in September/October 1993 indicates that channel 2 experienced a deterioration of approximate to 18 per cent (relative) immediately after launch while channel 1 was not appreciably affected. Formulae are given for the calculation of the post-launch calibration coefficients for the two channels. C1 QSS GRP INC,COLLEGE PK,MD 20740. RP Rao, CRN (reprint author), NOAA,NESDIS,OFF RES & APPLICAT,WASHINGTON,DC 20233, USA. NR 8 TC 151 Z9 153 U1 1 U2 2 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0143-1161 J9 INT J REMOTE SENS JI Int. J. Remote Sens. PD SEP 20 PY 1996 VL 17 IS 14 BP 2743 EP 2747 PG 5 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA VG227 UT WOS:A1996VG22700005 ER PT J AU Liu, WT Kogan, FN AF Liu, WT Kogan, FN TI Monitoring regional drought using the Vegetation Condition Index SO INTERNATIONAL JOURNAL OF REMOTE SENSING LA English DT Article ID AVHRR DATA; AREA; ENVIRONMENT; AFRICA; SAHEL; NDVI AB NDVI (Normalized Difference Vegetation Index) images generated from NOAA AVHRR GVI data were recently used to monitor large scale drought patterns and their climatic impact on vegetation. The purpose of this study is to use the Vegetation Condition Index (VCI) to further separate regional NDVI variation from geographical contributions in order to assess regional drought impacts. Weekly NDVI data for the period of July 1985 to June 1992 were used to produce NDVI and VCI images for the South American continent. NDVI data were smoothed with a median filtering technique for each year. Drought areas were delineated with certain threshold values of the NDVI and VCI. Drought patterns delineated by the NDVI and VCI agreed quite well with rainfall anomalies observed from rainfall maps of Brazil. NDVI values reflected the different geographical conditions quite well. Seasonal and interannual comparisons of drought areas delineated by the VCI provided a useful tool to analyse temporal and spatial evolution of regional drought as well as to estimate crop production qualitatively. It is suggested that VCI data besides NDVI may be used to construct a large scale crop yield prediction model. C1 NOAA,NESDIS,SATELLITE RES LAB,CAMP SPRINGS,MD 20746. RP Liu, WT (reprint author), UNIV SAO PAULO,INST ASTRON & GEOPHYS,DEPT ATMOSPHER SCI,RUA MATAO 1226,BR-05508900 SAO PAULO,BRAZIL. RI Kogan, Felix/F-5600-2010 OI Kogan, Felix/0000-0001-8216-900X NR 26 TC 109 Z9 142 U1 5 U2 19 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0143-1161 J9 INT J REMOTE SENS JI Int. J. Remote Sens. PD SEP 20 PY 1996 VL 17 IS 14 BP 2761 EP 2782 PG 22 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA VG227 UT WOS:A1996VG22700007 ER PT J AU Sanders, RW AF Sanders, RW TI Improved analysis of atmospheric absorption spectra by including the temperature dependence of NO2 SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID CROSS-SECTIONS; EQUILIBRIUM-CONSTANT; MCMURDO STATION; NM REGION; SPECTROSCOPY; N2O4; STRATOSPHERE; ANTARCTICA AB Absorption spectra of NO2 measured at several temperatures between room temperature and 197 K are used to improve the analysis of zenith view, atmospheric absorption data in the 405-430 nm spectral range. The size of persistent features in the residual spectrum of the analysis is reduced by up to 50%, which in principle facilitates measurement of weakly absorbing species, such as OClO and IO. Details of the reduction algorithm are discussed. RP Sanders, RW (reprint author), NOAA, AERON LAB, 325 BROADWAY, BOULDER, CO 80303 USA. NR 22 TC 34 Z9 34 U1 1 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP 20 PY 1996 VL 101 IS D15 BP 20945 EP 20952 DI 10.1029/96JD01699 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VJ677 UT WOS:A1996VJ67700004 ER PT J AU Ridley, BA Dye, JE Walega, JG Zheng, J Grahek, FE Rison, W AF Ridley, BA Dye, JE Walega, JG Zheng, J Grahek, FE Rison, W TI On the production of active nitrogen by thunderstorms over New Mexico SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID PRECIPITATION DEVELOPMENT; OZONE PRODUCTION; UNITED-STATES; ODD NITROGEN; TROPOSPHERE; FIXATION; CLOUD; DISTRIBUTIONS; COLORADO; OXIDES AB In July and August of 1989 the National Center for Atmospheric Research (NCAR) Sabreliner jet aircraft was used to probe electrically active and inactive convective storms over west central New Mexico to examine the production of odd nitrogen in the middle and upper troposphere by thunderstorms. In the anvil outflow or cloud top region of active and nonactive storms, the majority of flights showed that O-3 was reduced relative to the extracloud air owing to transport of ozone-poor air from lower altitudes. A similar result was found for active nitrogen (NOx) and total odd nitrogen (NOy) in nonelectrically active storms, but the reduction in NOy was also enhanced by removal of soluble constituents during convective transport. Examples of efficient removal from the gas phase are described. There was no evidence of O-3 production by lightning discharges. Indeed, O-3 was a goad tracer over the lifetime (similar to 1 hour) of the storms. During the active-to-mature stage of air mass thunderstorms, large enhancements in active nitrogen were observed in the anvil altitude region (9-11.8 km) and, in one case, in the midlevel outflow (near 7 km) of a dissipating thunderstorm. Two thunderstorms allow good estimates of the NOx production by lightning within or transport to the upper altitude region (8-11.8 km). Thunderstorms of August 12 and August 19 yield amounts in the range of 253-296 kg(N) and 263-305 kg(N), respectively. If, as an exercise, these amounts are extrapolated to the global scale on the basis of the number of cloud-to-ground and intracloud lightning flashes counted or estimated for each storm and a global flash frequency of 100 s(-1) the result is 2.4-2.7 and 2.0-2.2 Tg(N)/yr. Alternatively, an estimate for the two storms made on the basis of the average number of thunderstorms that occur per day globally (44,000) yields amounts in the range of 4.1-4.7 and 4.2-4.9 Tg(N)/yr, respectively. These estimates only apply to the production or transport of lightning generated NOx in or to the altitude region between 8 km and the top of the thunderstorm anvil (similar to 11.8 km in these studies). Since in some large-scale models, lightning-generated NOx is equally distributed by mass into each tropospheric layer, our estimates are roughly equivalent to those model runs that use a global source strength of about twice our estimate for the upper altitude region. In several flights where the region below the base of thunderstorms was examined, no large enhancements in odd nitrogen which could be clearly attributed to lightning were observed. Apparently, the aircraft was not in the right place at the right time. Thus no estimate of the NOx production by lightning that remains below similar to 8 km could be made. C1 NEW MEXICO INST MIN & TECHNOL, GEOPHYS RES CTR, SOCORRO, NM 87801 USA. NATL CTR ATMOSPHER RES, MESOSCALE MICROSCALE METEOROL DIV, BOULDER, CO 80307 USA. UNIV COLORADO, COOPERAT INST RES ENVIRONM SCI, BOULDER, CO 80309 USA. NOAA, AERON LAB, BOULDER, CO 80303 USA. RP Ridley, BA (reprint author), NATL CTR ATMOSPHER RES, DIV ATMOSPHER CHEM, POB 3000, BOULDER, CO 80307 USA. NR 38 TC 69 Z9 71 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP 20 PY 1996 VL 101 IS D15 BP 20985 EP 21005 DI 10.1029/96JD01706 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VJ677 UT WOS:A1996VJ67700008 ER PT J AU Rudich, Y Talukdar, RK Ravishankara, AR AF Rudich, Y Talukdar, RK Ravishankara, AR TI Reactive uptake of NO3 on pure water and ionic solutions SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID NITRIC-ACID SOLUTIONS; NIGHTTIME CHEMISTRY; AQUEOUS-SOLUTIONS; RATE CONSTANTS; NITRATE; KINETICS; RADICALS; OH; TROPOSPHERE; MECHANISMS AB The reactive uptake coefficients (gamma) of NO3 onto pure water and dilute solutions of NaCl, NaBr, and NaNO2 were measured using a wetted-wall flow-tube setup combined with a long-path absorption cell for the detection of NO3. The measured gamma values were in the range 1.5x10(-4)-6x10(-3), depending on the salt concentration in the water. By measuring gamma as a function of salt concentration, HDl0.5 for NO3 in water was determined to be (1.9+/-0.4)x10(-3) M atm(-1) cm s(-0.5) at 273 K, assuming that the rate coefficient for the reaction of NO3 with CP is 2.76x10(6) M(-1) s(-1) at 273 K. The Henry's law coefficient for NO3 in water is estimated to be 0.6+/-0.3 M atm(-1), assuming that the diffusion coefficient of NO3 in water is D-l=(1.0+/-0.5)x10(-5) cm(2) s(-1). Uptake of NO3 on pure water is interpreted as due to reaction of NO3(aq) with H2O(l) to produce HNO3 and OH in the liquid phase. Implications of these findings to the chemistry of NO3 in the troposphere are also discussed. C1 NATL INST STAND & TECHNOL, DIV TIME & FREQUENCY, BOULDER, CO 80303 USA. UNIV COLORADO, COOPERAT INST RES ENVIRONM SCI, BOULDER, CO 80309 USA. UNIV COLORADO, DEPT CHEM & BIOCHEM, BOULDER, CO 80309 USA. RP Rudich, Y (reprint author), NOAA, AERON LAB, R-E-AL2, 325 BROADWAY, BOULDER, CO 80303 USA. RI Rudich, Yinon/K-1498-2012; TALUKDAR, RANAJIT/G-4530-2013; Ravishankara, Akkihebbal/A-2914-2011; OI TALUKDAR, RANAJIT/0000-0001-6017-8431; Rudich, Yinon/0000-0003-3149-0201 NR 47 TC 88 Z9 88 U1 1 U2 12 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP 20 PY 1996 VL 101 IS D15 BP 21023 EP 21031 DI 10.1029/96JD01844 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VJ677 UT WOS:A1996VJ67700010 ER PT J AU Kukkonen, JVK Eadie, BJ Oikari, A Holmbom, B Lansing, MB AF Kukkonen, JVK Eadie, BJ Oikari, A Holmbom, B Lansing, MB TI Chlorophenolic and isotopic tracers of pulp mill effluent in sedimenting particles collected from Southern Lake Saimaa, Finland SO SCIENCE OF THE TOTAL ENVIRONMENT LA English DT Article DE pulp mill effluent; suspended particles; sedimentation; chlorophenols; carbon isotopes; nitrogen isotopes; stable isotopes; delta N-15; delta C-13 ID POLYCYCLIC AROMATIC-HYDROCARBONS; PARTICULATE ORGANIC-MATTER; TRAP; RESUSPENSION; SORPTION; BIOAVAILABILITY; POLLUTANTS; TOXICOKINETICS; CHLOROLIGNIN; MICHIGAN AB Sediment traps were used to collect settling particles at two stations upstream of a pulp and paper mill and at four stations along the effluent gradient in Southern Lake Saimaa. The particle samples were collected monthly from May to October 1991. Trap materials were analyzed for concentration and stable isotopic composition of organic carbon and nitrogen. The May 1991 trap samples and water and surface sediment samples from the trap locations were also analyzed for chlorophenolics. The trapped particle flux in May was 6.4 g(dry wt.)/m(2)/day at the station closest to the pulp mill(3.3 km) and decreased to 2.6 g(dry wt.)/m(2)/day at the farthest station (16.1 km). The organic carbon content of the particles varied from 10.5% to 22.1% and was the highest at the station nearest to the mill. There was a strong point source signal in the nitrogen isotope composition of effluent material. The other sampling times revealed a similar pattern. The total concentration of chlorophenols, chloroguaiacols and chlorocatechols was 0.8, 17.1 and 16.3 mu g/g (dry wt.) particles, respectively, at the nearest station and decreased downstream. The total extractable organic halogens in particles exhibited a similar concentration pattern to the identified chlorinated compounds. While about 60% of chloroguaiacols and about 90% of chlorocatechols are removed by sedimentation or degradation processes in the recipient area, most of the chlorophenols and adsorbable organic halogens are transported through the system. C1 NOAA,GREAT LAKES ENVIRONM RES LAB,ANN ARBOR,MI 48105. UNIV JYVASKYLA,DEPT BIOL & ENVIRONM SCI,FIN-40351 JYVASKYLA,FINLAND. ABO AKAD UNIV,LAB FOREST PROD CHEM,FIN-20500 TURKU,FINLAND. RP Kukkonen, JVK (reprint author), UNIV JOENSUU,DEPT BIOL,LAB AQUAT TOXICOL,POB 111,FIN-80101 JOENSUU,FINLAND. NR 39 TC 20 Z9 20 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0048-9697 J9 SCI TOTAL ENVIRON JI Sci. Total Environ. PD SEP 20 PY 1996 VL 188 IS 1 BP 15 EP 27 DI 10.1016/0048-9697(96)05148-0 PG 13 WC Environmental Sciences SC Environmental Sciences & Ecology GA VJ179 UT WOS:A1996VJ17900003 ER PT J AU Battle, M Bender, M Sowers, T Tans, PP Butler, JH Elkins, JW Ellis, JT Conway, T Zhang, N Lang, P Clarke, AD AF Battle, M Bender, M Sowers, T Tans, PP Butler, JH Elkins, JW Ellis, JT Conway, T Zhang, N Lang, P Clarke, AD TI Atmospheric gas concentrations over the past century measured in air from firn at the South Pole SO NATURE LA English DT Article ID ANTARCTIC ICE CORE; NITROUS-OXIDE; O-2; RATIO; CO2; N-2; N2O; METHANE; MODEL AB The extraction and analysis of air from the snowpack (firn) at the South Pole provides atmospheric concentration histories of biogenic greenhouse gases since the beginning of the present century which confirm and expand on those derived from studies of air trapped in ice cores. Furthermore, calculations based on the inferred atmospheric concentrations of oxygen and carbon dioxide indicate that-in contrast to the past few years-the terrestrial biosphere was neither a source nor sink of CO2 between similar to 1977 and 1985. C1 PENN STATE UNIV, DEPT GEOSCI, UNIVERSITY PK, PA 16802 USA. NOAA, CLIMATE MONITORING & DIAGNOST LAB, BOULDER, CO 80303 USA. UNIV COLORADO, COOPERAT INST RES ENVIRONM STUDIES, BOULDER, CO 80309 USA. RP Battle, M (reprint author), UNIV RHODE ISL, GRAD SCH OCEANOG, NARRAGANSETT, RI 02882 USA. RI Zhang, Nina/F-3609-2014 NR 51 TC 178 Z9 187 U1 4 U2 23 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD SEP 19 PY 1996 VL 383 IS 6597 BP 231 EP 235 DI 10.1038/383231a0 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA VH315 UT WOS:A1996VH31500045 ER PT J AU Hsu, SM AF Hsu, SM TI Fundamental Mechanisms of friction and lubrication of materials SO LANGMUIR LA English DT Article; Proceedings Paper CT Workshop on the Physical and Chemical Mechanisms of Tribology CY AUG 28-SEP 01, 1995 CL BAR HARBOR, ME ID BOUNDARY LUBRICATION; SILICON-NITRIDE; CONTACT; SURFACES; TEMPERATURES; EMISSION; MODEL AB The fundamental mechanisms of friction and lubrication are reviewed from an engineering perspective. The review integrates information from mechanical engineering, chemistry, and contact mechanics research results to provide a universal view of the area of tribology at this time. This view is to be contrasted by subsequent views from the molecular perspective. RP Hsu, SM (reprint author), NIST,GAITHERSBURG,MD 20899, USA. NR 23 TC 22 Z9 22 U1 1 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0743-7463 J9 LANGMUIR JI Langmuir PD SEP 18 PY 1996 VL 12 IS 19 BP 4482 EP 4485 DI 10.1021/la9508856 PG 4 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA VH414 UT WOS:A1996VH41400002 ER PT J AU Lee, AT Richards, PL Nam, SW Cabrera, B Irwin, KD AF Lee, AT Richards, PL Nam, SW Cabrera, B Irwin, KD TI A superconducting bolometer with strong electrothermal feedback SO APPLIED PHYSICS LETTERS LA English DT Article AB We present a theoretical analysis and experimental evaluation of a transition-edge superconducting bolometer for detecting infrared and millimeter waves. The superconducting film is voltage biased and the current is read by a superconducting quantum interference device ammeter. Strong electrothermal feedback maintains the sensor temperature within the transition, gives a current responsivity that is simply the inverse of the bias voltage, and reduces the response time by several orders of magnitude below the intrinsic time constant C/G. We evaluated a voltage-biased bolometer that operates on the T-c similar to 95 mK transition of a tungsten film with a thermal conductance of G similar to 1.2 x 10(-9) W/K. As expected, the electrical noise equivalent power of 3.3 x 10(-17)/W root Hz is close to the thermal fluctuation noise limit and is lower than that of other technologies for these values of G and temperature. The measured time constant of 10 mu s is similar to 100 times faster than the intrinsic time constant. (C) 1996 American Institute of Physics. C1 STANFORD UNIV,DEPT PHYS,STANFORD,CA 94305. NIST,BOULDER,CO 80303. UNIV CALIF BERKELEY,CTR PARTICLE ASTROPHYS,BERKELEY,CA 94720. RP Lee, AT (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. NR 14 TC 147 Z9 150 U1 2 U2 7 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD SEP 16 PY 1996 VL 69 IS 12 BP 1801 EP 1803 DI 10.1063/1.117491 PG 3 WC Physics, Applied SC Physics GA VG934 UT WOS:A1996VG93400050 ER PT J AU Keller, MW Martinis, JM Zimmerman, NM Steinbach, AH AF Keller, MW Martinis, JM Zimmerman, NM Steinbach, AH TI Accuracy of electron counting using a 7-junction electron pump SO APPLIED PHYSICS LETTERS LA English DT Article AB We have operated a 7-junction electron pump as an electron counter with an error per pumped electron of 15 parts in 10(9) and an average hold time of 600 s. The accuracy and hold time are sufficient to enable a new fundamental standard of capacitance. We compare the measured accuracy of the pump as a function of pumping speed and temperature with theoretical predictions based on a model which includes stray capacitance. (C) 1996 American Institute of Physics. C1 NIST, GAITHERSBURG, MD 20899 USA. UNIV COLORADO, BOULDER, CO 80309 USA. RP NIST, BOULDER, CO 80303 USA. NR 9 TC 233 Z9 235 U1 0 U2 9 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0003-6951 EI 1077-3118 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD SEP 16 PY 1996 VL 69 IS 12 BP 1804 EP 1806 DI 10.1063/1.117492 PG 3 WC Physics, Applied SC Physics GA VG934 UT WOS:A1996VG93400051 ER PT J AU Butler, JM JiangBaucom, P Huang, M Belgrader, P Girard, J AF Butler, JM JiangBaucom, P Huang, M Belgrader, P Girard, J TI Peptide nucleic acid characterization by MALDI-TOF mass spectrometry SO ANALYTICAL CHEMISTRY LA English DT Article ID LASER-DESORPTION IONIZATION; MATRIX; OLIGONUCLEOTIDES; DNA; PNA AB Peptide nucleic acids (PNAs) are a new class of DNA mimics in which the regular nucleobases of adenine, thymine, cytosine, and guanine are connected via a peptide-like backbone, PNA molecules retain the same Watson-Crick base pairing as regular oligonucleotides, with the added benefits of greater specificity and resistance to enzymatic digestion, While the use of PNAs has grown rapidly because of their potential applications in biotechnology, little work has been done on developing analytical procedures for characterizing them, We have found matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry to be an effective tool for PNA analysis. PNA molecules survive the MALDI process intact and are easily ionized with almost no multiply-charged species. These features allow mixtures to be easily characterized. Traditional protein matrices (e.g., sinapinic acid, 2,5-dihydroxybenzoic acid, alpha-cyano-4-hydroxycinnamic acid) were found to be superior to DNA matrices (e.g., trihydroxy-acetophenone, 3-hydroxypicolinic acid, picolinic acid). In addition, the new DNA matrix 6-aza-2-thiothymine worked well. The ability of MALDI-TOF-MS to ascertain PNA purity and sequence information at low picomole levels will be important as greater quality control of PNA synthesis is needed (e.g., when PNAs are used as antisense or antigene drugs). C1 AMERICAN UNIV,DEPT CHEM,WASHINGTON,DC 20016. NIST,DIV BIOTECHNOL,GAITHERSBURG,MD 20899. ARMED FORCES INST PATHOL,ARMED FORCES DNA IDENTIFICAT LAB,ROCKVILLE,MD 20850. RI Butler, John/C-7812-2011 NR 26 TC 41 Z9 43 U1 0 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD SEP 15 PY 1996 VL 68 IS 18 BP 3283 EP 3287 DI 10.1021/ac960317a PG 5 WC Chemistry, Analytical SC Chemistry GA VG141 UT WOS:A1996VG14100032 PM 8797387 ER PT J AU Gonzalez, WD Tsurutani, BT McIntosh, PS deGonzalez, AL AF Gonzalez, WD Tsurutani, BT McIntosh, PS deGonzalez, AL TI Coronal Hole Active Region Current Sheet (CHARCS) association with intense interplanetary and geomagnetic activity SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID MAJOR MAGNETIC STORMS; MASS EJECTIONS; DISTURBANCES AB Intense geomagnetic storms (Dst less than or equal to -100 nT) have been associated with interplanetary structures involving large-intensity (B-s greater than or equal to 10 nT) and long-duration (T greater than or equal to 3 hours) values of the southward cam component of the IMF. We show that near solar maximum, the solar origin of such structures seems to be associated with active regions* (involving flares and/ or filament eruptions) occurring close to the streamer belt and to growing low-latitude coronal holes. It is also shown that low-latitude coronal holes had a dual-peak solar cycle distribution during solar cycle 21, similar to that previously reported for the above mentioned interplanetary and geomagnetic phenomena. C1 NOAA, SPACE ENVIRONM LAB, BOULDER, CO 80303 USA. CALTECH, JET PROP LAB, PASADENA, CA 91109 USA. RP Gonzalez, WD (reprint author), INPE, CP 515, BR-12201970 SAO JOSE DOS CAMPOS, SP, BRAZIL. NR 16 TC 40 Z9 40 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD SEP 15 PY 1996 VL 23 IS 19 BP 2577 EP 2580 DI 10.1029/96GL02393 PG 4 WC Geosciences, Multidisciplinary SC Geology GA VH169 UT WOS:A1996VH16900001 ER PT J AU Lienesch, JH Planet, WG DeLand, MT Laamann, K Cebula, RP Hilsenrath, E Horvath, K AF Lienesch, JH Planet, WG DeLand, MT Laamann, K Cebula, RP Hilsenrath, E Horvath, K TI Validation of NOAA-9 SBUV/2 total ozone measurements during the 1994 Antarctic ozone hole SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SOLAR BACKSCATTER ULTRAVIOLET; INSTRUMENT AB The Solar Backscatter Ultraviolet (SBUV/2) instrument on the NOAA-9 spacecraft made total ozone measurements over Antarctica during the 1994 Austral Spring depletion. These measurements continue those made by the SBUV/2 on NOAA-11. In recent years NOAA-9 drifted from a poor orbit to one where earth observations and calibration capabilities are not restricted. An interim calibration of the NOAA-9 SBUV/2 instrument was established with data from June 1994 and applied to observations during September, October, and November 1994. To validate the NOAA-9 ozone measurements, daily zonal ozone averages from NOAA-9 and NOAA-11 measurements in the Northern Hemisphere have been compared. Comparisons have also been made with ground-based measurements from five Dobson stations dispersed on the Antarctic continent. The results show that, on average, the NOAA-9 data agree to within 1-2 percent with the Dobson stations with standard deviations of the difference ranging from 5.3 to 7.7% and to within several percent with NOAA-11 Northern Hemisphere data when restricted to solar zenith angles less than 80 degrees. This agreement makes possible not only a continuation of the Antarctic measurements without a large instrument-related bias, but also establishes the NOAA-9 data as a suitable transition data set during the replacement of NOAA-11 by NOAA-14. C1 HUGHES STX CORP,GREENBELT,MD 20770. GODDARD SPACE FLIGHT CTR,ATMOSPHERES LAB,GREENBELT,MD 20771. RES & DATA SYST CORP,RDC,GREENBELT,MD 20770. NOAA,NATL ENVIRONM SATELLITE DATA & INFORMAT SERV,CAMP SPRINGS,MD. NR 13 TC 6 Z9 6 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD SEP 15 PY 1996 VL 23 IS 19 BP 2593 EP 2596 DI 10.1029/96GL02417 PG 4 WC Geosciences, Multidisciplinary SC Geology GA VH169 UT WOS:A1996VH16900005 ER PT J AU Schafer, JS Saxena, VK Wenny, BN Barnard, W DeLuisi, JJ AF Schafer, JS Saxena, VK Wenny, BN Barnard, W DeLuisi, JJ TI Observed influence of clouds on ultraviolet-B radiation SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SOLAR; IRRADIANCE; AEROSOLS; UV AB Brewer Spectrophotometer was utilized to make ground-based measurements of solar ultraviolet (WE) radiation received at Black Mountain, NC (35.66 degrees N) in order to quantify the reduction of UV-B due to cloud cover. Observations were made over the interval February-July 1995 with continuous coverage except for a three-week period in May. A wide-angle lens video camera at the site was used for the assessment of cloud conditions at the time of each scan. integrated UV-B (290-320 nm) values were evaluated and a regression through the values for clear conditions was produced for the range of zenith angles from 25 degrees - 70 degrees. This regression effectively represents an average effect of the ambient aerosols and attenuating gases and was used to normalize the UV-B values measured under different cloud cover an estimate of the reduction in irradiance due to a given cloud amount as a function of solar zenith angle. For a solar zenith angle of 50 degrees, average UV-B transmission was observed to be 30% for overcast skies, 6156 for 8-9 tenths cloud cover, 74% for 6-7 tenths cover, and 79% for the scans during 4-5 tenths cover. A number of fractional cloud cover cases were observed where cloud reflections resulted in measured surface irradiances exceeding the expected clear sky values by as much as 11 percent. C1 N CAROLINA STATE UNIV,DEPT MARINE EARTH & ATMOSPHER SCI,RALEIGH,NC 27695. ATMOSPHER RES & EXPOSURE ASSESSMENT LABS,RES TRIANGLE PK,NC. NOAA,SURFACE RADIAT RES BRANCH,BOULDER,CO. RI Schafer, Joel/A-3978-2010 NR 12 TC 56 Z9 57 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD SEP 15 PY 1996 VL 23 IS 19 BP 2625 EP 2628 DI 10.1029/96GL01984 PG 4 WC Geosciences, Multidisciplinary SC Geology GA VH169 UT WOS:A1996VH16900013 ER PT J AU Dzierzega, K Musiol, K Benck, EC Roberts, JR AF Dzierzega, K Musiol, K Benck, EC Roberts, JR TI Electron density measurement in a rf helium plasma by laser-collision induced fluorescence method SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID CONFERENCE REFERENCE REACTOR; LANGMUIR PROBE; REFERENCE CELL; GLOW-DISCHARGE; TEMPERATURE AB Laser-collision induced fluorescence (LCIF) is the emission of light from states that have been populated by laser excitation and a subsequent collision. By simultaneously measuring the LCIF from two different states, it is possible to determine both the electron density and temperature of the low energy bulk electrons within a plasma. This method is described in detail and has been applied in the determination of the total, temporally averaged, and spatially resolved electron density in a rf (13.56 MHz) helium discharge in the Gaseous Electronics Conference reference cell. The rf discharge was operated at pressures P=33.3-133.3 Pa (0.25-1.0 Torr) and peak-to-peak voltages of V-pp=75-300 V were applied. We found the total electron density varied from 1.8X10(8) cm(-3) at P=33.3 Pa and V-pp=75 V to 4.0x10(10) cm(-3) at P=133.3 Pa and V-pp=300 V. A comparison of results from different experiments has been made. (C) 1996 American Institute of Physics. C1 JAGIELLONIAN UNIV,PL-30059 KRAKOW,POLAND. RP Dzierzega, K (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 22 TC 19 Z9 19 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD SEP 15 PY 1996 VL 80 IS 6 BP 3196 EP 3201 PG 6 WC Physics, Applied SC Physics GA VG681 UT WOS:A1996VG68100010 ER PT J AU Anderson, DT Davis, S Nesbitt, DJ AF Anderson, DT Davis, S Nesbitt, DJ TI Hydrogen bond spectroscopy in the near infrared: Out-of-plane torsion and antigeared bend combination bands in (HF)(2) SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID POTENTIAL-ENERGY SURFACE; QUASI-ADIABATIC CHANNELS; MONTE-CARLO CALCULATIONS; WEAKLY-BOUND COMPLEXES; HF-HF COLLISIONS; VIBRATIONAL PREDISSOCIATION; FLUORIDE DIMER; ABINITIO CALCULATION; BASIS SET; SPECTRA AB High-resolution near infrared spectra of the two ''high'' frequency intermolecular modes of (HF), have been characterized in HF-stretch excited states using a slit jet spectrometer. In the spectral region between 4280 and 4480 cm(-1), four vibration-rotation-tunneling (VRT) bands are observed and assigned to tunneling pairs of the out-of-plane torsion (nu(6)) and antigeared bend (nu(3)) intermolecular modes, in combination with the hydrogen bond donor (nu(2)) and acceptor (nu(1)) high-frequency intramolecular HF stretches, respectively. Analysis of the jet-cooled, rotationally resolved spectra provide intermolecular frequencies, rotational constants, tunneling splittings, and predissociation rates for the nu(3)/nu(6) intermolecular excited states. The relatively small changes in the hydrogen bond interconversion tunneling splitting with either nu(3) or nu(6) excitation indicate that neither intermolecular mode is strongly coupled to the tunneling coordinate. The high-resolution VRT linewidths reveal mode specific predissociation broadening sensitive predominantly to intramolecular excitation, but with significant additional effects due to low-frequency intermolecular excitation as well. The intermolecular vibrational frequencies in the combination states display a systematic dependence on intramolecular redshift that allows all four intermolecular fundamental frequencies to be extrapolated from the near-ir data. Agreement between full 6-D quantum calculations and experiment for the out-of-plane torsion (Vg) vibration is remarkably good (0.5%). However, significant discrepancies (> 10%) between theory and experiment are obtained for the antigeared bend (nu(3)), indicating the need for further refinement of the HF dimer potential surface. Finally, the observation of all four intermolecular modes allows zero-point contributions to the binding energy to be reliably estimated. The revised value for the binding energy, D-e = 1580(35) cm(-1), is slightly higher than semiempirical estimates but now in excellent agreement with recent high level ab initio calculations. (C) 1996 American Institute of Physics. C1 UNIV COLORADO, NATL INST STAND & TECHNOL, BOULDER, CO 80309 USA. UNIV COLORADO, DEPT CHEM & BIOCHEM, BOULDER, CO 80309 USA. RP Anderson, DT (reprint author), UNIV COLORADO, JOINT INST LAB ASTROPHYS, BOULDER, CO 80309 USA. NR 78 TC 50 Z9 50 U1 1 U2 9 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-9606 EI 1089-7690 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 15 PY 1996 VL 105 IS 11 BP 4488 EP 4503 DI 10.1063/1.472293 PG 16 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VG932 UT WOS:A1996VG93200009 ER PT J AU AdamutiTrache, M McMullen, WE Douglas, JF AF AdamutiTrache, M McMullen, WE Douglas, JF TI Segmental concentration profiles of end-tethered polymers with excluded-volume and surface interactions SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID DIBLOCK COPOLYMER MONOLAYERS; FIELD-THEORETICAL APPROACH; LIQUID AIR INTERFACE; RENORMALIZATION-GROUP; MONTE-CARLO; NEUTRON REFLECTIVITY; DENSITY PROFILE; MOLECULAR-DYNAMICS; PENETRABLE SURFACE; FLEXIBLE POLYMERS AB The segmental concentration profile rho of end-tethered flexible polymer chains is calculated for comparison with recent measurements on polymer layers having a low surface grafting density sigma. Moments of rho are also calculated as these quantities, rather than the full concentration profiles, are usually measured experimentally. Exact calculations of rho are summarized for ideal flexible chains with an arbitrary short-range polymer-surface interaction. Though technical difficulties restrict our renormalization group (RG) calculations for swollen chains to limiting values of the polymer-surface interaction, our analysis indicates that the relatively simple, closed-form, Gaussian-chain expression for rho provides a good approximation to the RG results if the average size of the Gaussian chain is replaced by its swollen-chain analog. This approximate concentration profile for chains with excluded volume and variable polymer-surface interaction should prove useful when interpreting experimental results for low-grafting-density polymer layers formed in good solvents. Recent measurements [Kent ct al., J. Chem. Phys. 103, 2320 (1995)] of the second moment of rho in the limit sigma-->0 agree well with our RG calculations, and the measured concentration profile rho, whose determination by neutron reflection is somewhat uncertain, agrees qualitatively with our theoretical predictions. (C) 1996 American Institute of Physics. C1 TEXAS A&M UNIV,DEPT CHEM,COLLEGE STN,TX 77843. NIST,DIV POLYMERS,GAITHERSBURG,MD 20899. NR 70 TC 26 Z9 26 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 15 PY 1996 VL 105 IS 11 BP 4798 EP 4811 PG 14 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VG932 UT WOS:A1996VG93200039 ER PT J AU Zhang, RH Levitus, S AF Zhang, RH Levitus, S TI Structure and evolution of interannual variability of the tropical Pacific upper ocean temperature SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID SEA-SURFACE TEMPERATURE; GENERAL-CIRCULATION MODEL; HEAT-CONTENT VARIABILITY; EL-NINO CYCLES; SOUTHERN-OSCILLATION; ROSSBY WAVES; EQUATORIAL PACIFIC; ATMOSPHERE INTERACTION; COUPLED GCM; ENSO AB Yearly in situ temperature anomaly data for the period 1961-1990 are analyzed to reveal the dominant structure and evolution of interannual variability of the tropical Pacific upper ocean. We use multivariate empirical orthogonal function (EOF) analyses to detect the principal three-dimensional structure related to El Nino. There are well-defined subsurface thermal patterns, characterized by a prominent sea-saw structure with opposite anomaly polarity in the equatorial and off-equatorial tropical North Pacific regions. During an El Nino year a positive temperature anomaly is found in the-e-astern and central tropical upper ocean. This is accompanied by a corresponding negative anomaly at subsurface depths in the west, with a maximum at 100-150 m off the equator. Unlike sea surface temperature, whose variations are confined largely to the east with one dominant polarity, temperature variations at 50-200 m depths have a dipole pattern with out-of-phase oscillations in the central equatorial Pacific and in the western tropical North Pacific. A reverse pattern of these anomalies is observed during a La Nina year. Evolution between El Nino and La Nina involves a significant zonal transfer of anomaly phase across the equatorial basin as well as across the off-equatorial tropical North Pacific, showing consistent and coherent variations from west to east, from subsurface to sea surface, and from on the equator to off the equator. This phase propagation is more evident at subsurface depths than that at the sea surface, suggesting a continual movement of anomaly pattern in succession, eastward along the equator and westward off the equator of the tropical North Pacific, with spatial inhomogeneities of zonal propagation in longitude. Our analyses present evidence of the manner in which temperature anomalies evolve at subsurface ocean depths in the tropical Pacific, thus providing an observational basis for evaluating theoretical studies and model simulations. The dynamical implication of these results is also discussed. C1 NOAA,NATL OCEAN DATA CTR,SILVER SPRING,MD 20910. NR 50 TC 36 Z9 46 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD SEP 15 PY 1996 VL 101 IS C9 BP 20501 EP 20524 DI 10.1029/96JC01805 PG 24 WC Oceanography SC Oceanography GA VH015 UT WOS:A1996VH01500003 ER PT J AU Warner, MJ Bullister, JL Wisegarver, DP Gammon, RH Weiss, RF AF Warner, MJ Bullister, JL Wisegarver, DP Gammon, RH Weiss, RF TI Basin-wide distributions of chlorofluorocarbons CFC-11 and CFC-12 in the north Pacific: 1985-1989 SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID SHALLOW SALINITY MINIMA; TROPICAL MODE WATER; INTERMEDIATE WATER; OCEAN; CHLOROFLUOROMETHANES; VENTILATION; DEEP; SEAWATER; ATLANTIC; TRITIUM AB All of the dissolved chlorofluorocarbon measurements made between 1985 and 1989 along several long zonal and meridional hydrographic sections in the North Pacific are presented in this manuscript. Chlorofluorocarbon (CFC) concentrations are displayed as functions of depth and density along the sections. Over much of the region studied, dissolved CFCs are observed to have penetrated to densities greater than those that outcrop at the surface in the North Pacific (sigma(theta) > 26.8). Maxima in CFC concentration are associated with remnant winter mixed layers and with mode waters. When the observed CFC concentrations from these sections are normalized to a common date and mapped onto five density surfaces in the North Pacific, it becomes apparent that the Sea of Okhotsk is an important location for the ventilation of the intermediate waters of the North Pacific. The CFC observations are used together with hydrographic data to study the pathways and timescales of circulation and ventilation processes in the upper and intermediate waters of the North Pacific. Using models of the increases of these compounds as a function of time, CFC ''apparent ages'' are calculated on these isopycnal surfaces. The CFC apparent ages are used together with observed apparent oxygen utilization to estimate oxygen utilization rates along these sections. C1 NOAA,PACIFIC MARINE ENVIRONM LAB,SEATTLE,WA 98115. UNIV CALIF SAN DIEGO,SCRIPPS INST OCEANOG,LA JOLLA,CA 92093. RP Warner, MJ (reprint author), UNIV WASHINGTON,SCH OCEANOG,BOX 357940,SEATTLE,WA 98195, USA. NR 54 TC 144 Z9 147 U1 1 U2 15 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD SEP 15 PY 1996 VL 101 IS C9 BP 20525 EP 20542 DI 10.1029/96JC01849 PG 18 WC Oceanography SC Oceanography GA VH015 UT WOS:A1996VH01500004 ER PT J AU Treguier, AM Dukowicz, JK Bryan, K AF Treguier, AM Dukowicz, JK Bryan, K TI Properties of nonuniform grids used in ocean general circulation models SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID NET DIFFUSIVITY AB Ocean general circulation models frequently use nonuniform grids, especially in the vertical direction. This paper clarifies the implications of using such grids on the consistency and accuracy of numerical schemes. It is emphasized that numerical schemes maintain their order of accuracy on a nonuniform grid provided the grid can be related to a smooth mapping. Additional metric terms appear in the truncation error, which should not be interpreted simply as a numerical diffusion. C1 IFREMER, LAB PHYS OCEANS, F-29280 PLOUZANE, FRANCE. LOS ALAMOS NATL LAB, LOS ALAMOS, NM USA. PRINCETON UNIV, GEOPHYS FLUID DYNAM LAB, PRINCETON, NJ 08544 USA. RI Treguier, Anne Marie/B-7497-2009 OI Treguier, Anne Marie/0000-0003-4569-845X NR 8 TC 15 Z9 15 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9275 EI 2169-9291 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD SEP 15 PY 1996 VL 101 IS C9 BP 20877 EP 20881 DI 10.1029/96JC01753 PG 5 WC Oceanography SC Oceanography GA VH015 UT WOS:A1996VH01500028 ER PT J AU Rodriguez, B Hart, L Henderson, T AF Rodriguez, B Hart, L Henderson, T TI Parallelizing operational weather forecast models for portable and fast execution SO JOURNAL OF PARALLEL AND DISTRIBUTED COMPUTING LA English DT Article AB This paper describes a high-level library (The Nearest Neighbor Tool, NNT) that has been used to parallelize operational weather prediction models. NNT is part of the Scalable Modeling System (SMS), developed at the Forecast Systems Laboratory (FSL). Programs written in NNT rely on SMS's run-time system and port between a wide range of computing platforms, performing well in multiprocessor systems. We show, using examples from operational weather models, how large Fortran 77 codes can be parallelized using NNT. We compare the ease of programmability of NNT and High Performance Fortran (HPF). We also discuss optimizations like data movement overlap (in interprocessor communication and I/O operations), and the minimization of data exchanges through the use of redundant computations. We show that although HPF provides a simpler programming interface, NNT allows for program optimizations that increase performance considerably and still keeps a simple user interface. These optimizations have proven essential to run weather prediction models in real time, and HPF compilers should incorporate them in order to meet operational demands. Throughout the paper, we present performance results of weather models running on a network of workstations, the Intel Paragon, and the SGI Challenge. Finally, we study the cost of programming global address space architectures with NNT's local address space paradigm. (C) 1996 Academic Press, Inc. RP Rodriguez, B (reprint author), NOAA, FORECAST SYST LAB, HIGH PERFORMANCE COMP GRP, BOULDER, CO 80303 USA. NR 17 TC 3 Z9 4 U1 0 U2 1 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0743-7315 J9 J PARALLEL DISTR COM JI J. Parallel Distrib. Comput. PD SEP 15 PY 1996 VL 37 IS 2 BP 159 EP 170 DI 10.1006/jpdc.1996.0116 PG 12 WC Computer Science, Theory & Methods SC Computer Science GA VT720 UT WOS:A1996VT72000004 ER PT J AU Pearce, EM Sawamoto, M Tirrell, DA Amis, EJ AF Pearce, EM Sawamoto, M Tirrell, DA Amis, EJ TI A half-century of the Journal of Polymer Science SO JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS LA English DT Editorial Material RP Pearce, EM (reprint author), NATL INST STAND & TECHNOL,DIV POLYMERS,224-B210,POB 4043,GAITHERSBURG,MD 20885, USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0887-6266 J9 J POLYM SCI POL PHYS JI J. Polym. Sci. Pt. B-Polym. Phys. PD SEP 15 PY 1996 VL 34 IS 12 BP 1941 EP 1941 PG 1 WC Polymer Science SC Polymer Science GA VC183 UT WOS:A1996VC18300001 ER PT J AU Williams, GP AF Williams, GP TI Jovian dynamics .1. Vortex stability, structure, and genesis SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID EQUATORIAL SOLITARY WAVES; BETA-PLANE; GEOSTROPHIC REGIMES; CIRCULATION; SOLITONS; VORTICES; OCEAN; JETS; INSTABILITY; ATMOSPHERES AB The vertical structure of Jupiter's atmosphere is probed and isolated by evaluating the stability characteristics of planetary vortices over a wide parameter range. The resulting structures lead to simulating the genesis of single and multiple vortex states in Part I of this paper and the genesis of an equatorial superrotation and midlatitudinal multiple jets in Part II. The stability and genesis of baroclinic Rossby vortices, the vortices associated with long solitary Rossby waves in a stratified fluid are studied numerically using a primitive equation model with Jovian and oceanic parameters and hypothetical structures. Vortex stability, that is, coherence and persistence, depends primarily upon latitude location and vertical structure and is used to deduce possible stratifications for Jupiter's atmosphere. The solutions suggest that Jupiter's large-scale motions are confined to a layer of depth h and are bounded by an abyss with an impermeable interface at a depth H, such that h/H less than or equal to 1/20. Consequently, they also extend earlier results derived with the reduced-gravity, shallow-water model, particularly the explanation for the origin, uniqueness, and longevity of the Great Red Spot (GRS). Beginning at the equator, stable anticyclones are seen to exist only when they have the Hermitian latitudinal form, the Korteweg-deVries longitudinal form, the confined exponential vertical structure exp(Nz/H), and the amplitude range as prescribed by the analytical theory of Marshall and Boyd for N = 8. Soliton interactions occur between equatorial vortices of similar horizontal and vertical form. In middle and low latitudes, shallow anticyclones with an exponential structure of N = 20 exist quasi-stably for a variety of sizes. Such vortices remain coherent but lend to migrate equatorward (where they disperse) at rates that depend upon their size, location, and vertical structure: large and medium anticyclones propagate primarily westward while migrating slowly, whereas small storms just migrate rapidly and then collapse. The migration of these large, shallow vortices can be reduced, but not stopped, in low latitudes by an easterly jet with the same vertical structure. Anticyclones are stabler when they are thinner relative to the abyss. Thus, when N = 60, their migration is sufficiently slow that it can be stopped by a weak easterly jet. Furthermore, absolute stability sets in when N = 90 and migration ceases completely for the large, thin anticyclones that now just propagate westward. Such flows may also be usefully represented by a vertical structure that is linear in z for the velocity and static stability in the thin upper layer and vanishes in the abyss. Large, thin (N greater than or equal to 90) anticyclones can exist indefinitely either freely or when embedded within an anticyclonic zone of alternating jet streams of similar vertical structure. This holds true for the confined linear-z representation also. The permanence of GRS-like, low-latitude vortices in Jovian flow configurations occurs in a variety of lengthy calculations with thin structures. Ocean vortices are less persistent because the thermocline is relatively thick. The baroclinic instability of easterly jets is nonquasigeostrophic and lakes on the form of solitary rather than periodic waves when the jets have a thin exponential (N greater than or equal to 90) or confined linear-z structure. Such nonlinear waves develop into vortices that exhibit a variety of configurations and evolutionary paths. In most cases multiple mergers tend toward an end state with a single large vertex. Two types of merging occur in which a stronger vertex either catches a weaker one ahead of it or reels in a weaker one from behind. This duality occurs because propagation rates depend as much on local as on global conditions. In a further complication, vortices generated by an unstable easterly tend to have an exponential structure for exponential jets but a first baroclinic eigenmodal structure for confined linear-z jets. Single vortex states resembling the GRS, with sizes ranging from 15 degrees to 50 degrees in longitude and with temperature gradients, velocities, and propagation rates near the observed range, can be generated either directly through the growth of a local front in a marginally unstable easterly jet or indirectly through a series of mergers of the multiple vortices generated by a more unstable easterly jet. Sets of vortices can be produced simultaneously in the anticyclonic zones centered about latitudes -21 degrees, -33 degrees, and -41 degrees, and have the same relative scales as Jupiter's GRS, Large Ovals, and Small Ovals. Thin anticyclones can also be generated at the equator by the action of vortices lying in low latitudes. Equally realistic long-lived vortices can also be generated by jets with structures matching the recent Galileo spacecraft observations by using other hyperbolic forms and greater depth scales. RP Williams, GP (reprint author), PRINCETON UNIV,NOAA,GEOPHYS FLUID DYNAM LAB,POB 308,PRINCETON,NJ 08542, USA. NR 49 TC 33 Z9 33 U1 2 U2 7 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD SEP 15 PY 1996 VL 53 IS 18 BP 2685 EP 2734 DI 10.1175/1520-0469(1996)053<2685:JDPVSS>2.0.CO;2 PG 50 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VK779 UT WOS:A1996VK77900009 ER PT J AU Sinha, SK Feng, YP Melendres, CA Lee, DD Russell, TP Satija, SK Sirota, EB Sanyal, MK AF Sinha, SK Feng, YP Melendres, CA Lee, DD Russell, TP Satija, SK Sirota, EB Sanyal, MK TI Off-specular X-ray scattering studies of the morphology of thin films SO PHYSICA A LA English DT Article; Proceedings Paper CT Workshop on Colloid and Interface Science - Trends and Applications, on the Occasion of the Celebration of the 60th Birthday of Sow-Hsin Chen CY MAY 02-05, 1995 CL GUANICA, PR SP ES, PSCoR NSF, USN, Off Naval Res ID DIBLOCK COPOLYMER FILMS; NEUTRON REFLECTIVITY; MULTILAYER FILMS; ROUGH SURFACES; INSITU AB We discuss the scattering of X-rays from thin films at a surface or interface decorated with a morphology of islands and how these effects manifest themselves in the specular reflectivity and the diffuse (off-specular) scattering. We show how this technique has been used to study block copolymer films decorated with islands on the surface and the development of electrochemically induced pitting on a Cu electrode in an electrolyte solution. C1 ARGONNE NATL LAB,DIV CHEM TECHNOL,ARGONNE,IL 60439. MIT,DEPT NUCL ENGN,CAMBRIDGE,MA 02139. IBM CORP,ALMADEN RES CTR,SAN JOSE,CA 95120. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. EXXON RES & ENGN CO,CORP RES,ANNANDALE,NJ 08801. SAHA INST NUCL PHYS,CALCUTTA 700009,W BENGAL,INDIA. RP Sinha, SK (reprint author), ARGONNE NATL LAB,ADV PHOTON SOURCE,EXPT FACIL DIV,ARGONNE,IL 60439, USA. RI Sirota, Eric/A-7633-2009; Lee, Daniel/B-5753-2013; sanyal, milan/J-2527-2015 OI sanyal, milan/0000-0002-3847-8793 NR 21 TC 15 Z9 15 U1 1 U2 10 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-4371 J9 PHYSICA A JI Physica A PD SEP 15 PY 1996 VL 231 IS 1-3 BP 99 EP 110 DI 10.1016/0378-4371(96)00085-4 PG 12 WC Physics, Multidisciplinary SC Physics GA VH367 UT WOS:A1996VH36700008 ER PT J AU Shirley, EL AF Shirley, EL TI Self-consistent GW and higher-order calculations of electron states in metals SO PHYSICAL REVIEW B LA English DT Article ID BAND-STRUCTURE; QUASIPARTICLE ENERGIES; SEMICONDUCTORS; APPROXIMATION; INSULATORS; BANDWIDTH; POTASSIUM; GAPS; GAS AB Past work, treating simple metals in the GW approximation, has largely neglected effects of self-consistency and higher-order vertex corrections on occupied bandwidths. This work presents self-consistent GW results, plus nearly self-consistent higher-order results, for jellium, illustrating that both effects are large, yet largely canceling (e.g., 0.65-eV effects on the sodium bandwidth, but a combined effect of only 0.13 eV). This supports findings that many-body effects substantially reduce such bandwidths. RP Shirley, EL (reprint author), NIST,OPT TECHNOL DIV,GAITHERSBURG,MD 20899, USA. NR 32 TC 75 Z9 75 U1 0 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 1996 VL 54 IS 11 BP 7758 EP 7764 DI 10.1103/PhysRevB.54.7758 PG 7 WC Physics, Condensed Matter SC Physics GA VL145 UT WOS:A1996VL14500037 ER PT J AU Stepanov, SA Kondrashkina, EA Schmidbauer, M Kohler, R Pfeiffer, JU Jach, T Souvorov, AY AF Stepanov, SA Kondrashkina, EA Schmidbauer, M Kohler, R Pfeiffer, JU Jach, T Souvorov, AY TI Diffuse scattering from interface roughness in grazing-incidence x-ray diffraction SO PHYSICAL REVIEW B LA English DT Article ID SPECULAR REFLECTION CONDITIONS; ION-IMPLANTED SILICON; NEUTRON-SCATTERING; STANDING WAVES; THIN-FILMS; MULTILAYERS; SURFACES; GROWTH; SUPERLATTICES; RELAXATION AB A theory of x-ray diffuse scattering from interface roughness in grazing-incidence diffraction (GID) is presented. The theory assumes dynamical diffraction of x rays from perfect multilayers with the diffuse scattering from roughness calculated in the distorted-wave Born approximation. This permits the calculation of scattering due to roughness at all points on the diffraction curves, including the vicinity of the Bragg peaks. It is shown that the measurements of diffuse scattering in GID can provide information on atomic ordering at crystal interfaces which is not accessible by usual x-ray specular reflection and nonspecular x-ray scattering. The theory is found to be in good agreement to the two GID experiments carried out with an etched Ge surface and an AlAs/GaAs superlattice at the Cornell High-Energy Synchrotron Source and European Synchrotron Radiation Facility, respectively. In the case of the etched Ge surface, an anti-Yoneda dip in the diffuse scattering patten at the Bragg peak and two symmetrical shoulders on the Bragg curve wings have been found and explained. In the case of the AlAs/GaAs superlattice, the diffuse scattering has been separated from GID by means of high-resolution measurements. A comparison between diffuse scattering in GID and diffuse scattering in grazing incidence far from the diffraction conditions has shown that the atomic ordering was preserved in the interface roughness, while it was partially destroyed in the surface roughness. C1 NIST,GAITHERSBURG,MD 20899. EUROPEAN SYNCHROTRON RADIAT FACIL,F-38043 GRENOBLE,FRANCE. MINSK NUCL PROBLEMS INST,MINSK 220050,BYELARUS. RP Stepanov, SA (reprint author), MPG AG RONTGENBEUGUNG,HAUSVOGTEIPL 5-7,D-10117 BERLIN,GERMANY. NR 54 TC 30 Z9 32 U1 3 U2 9 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 1996 VL 54 IS 11 BP 8150 EP 8162 DI 10.1103/PhysRevB.54.8150 PG 13 WC Physics, Condensed Matter SC Physics GA VL145 UT WOS:A1996VL14500085 ER PT J AU Bolsenga, SJ Evans, M Vanderploeg, HA Norton, DG AF Bolsenga, SJ Evans, M Vanderploeg, HA Norton, DG TI PAR transmittance through thick, clear freshwater ice SO HYDROBIOLOGIA LA English DT Article DE ice PAR transmittance; freshwater ice; winter ecology ID LAKE ICE; NM AB Measurements of photosynthetically active radiation through clear freshwater ice 154-158 cm thick varied from 14.8 to 24.8% depending, in this case, primarily on the amount of flocullent material trapped within the ice. Transmittance in one area dropped to less than 1% with the presence of a 3 cm thick snow cover. Extinction coefficients varied from 0.014 to 0.010 cm(-1). C1 GREAT LAKES ENVIRONM RES LAB,ANN ARBOR,MI 48105. NATL HYDROL RES INST,SASKATOON,SK S7N 3H5,CANADA. OI Vanderploeg, Henry/0000-0003-1358-8475 NR 20 TC 7 Z9 7 U1 0 U2 3 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0018-8158 J9 HYDROBIOLOGIA JI Hydrobiologia PD SEP 13 PY 1996 VL 330 IS 3 BP 227 EP 230 DI 10.1007/BF00024210 PG 4 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA VP184 UT WOS:A1996VP18400006 ER PT J AU Meyers, TR Morado, JF Sparks, AK Bishop, GH Pearson, T Urban, D Jackson, D AF Meyers, TR Morado, JF Sparks, AK Bishop, GH Pearson, T Urban, D Jackson, D TI Distribution of Bitter Crab Syndrome in Tanner crabs (Chionoecetes bairdi, C-opilio) from the Gulf of Alaska and the Bering Sea SO DISEASES OF AQUATIC ORGANISMS LA English DT Article DE Tanner crab; dinoflagellates; BCS AB During 1988 to 1991, sampling efforts were conducted to determine prevalences of Bitter Crab Syndrome (BCS) in Tanner crabs from the Gulf of Alaska,:he Bering Sea and the boundary area of the Chukchi Sea and Arctic Ocean. Stained hemolymph smears indicated that prevalences of BCS in Chionoecetes bairdi from the Gulf of Alaska were zero to 7.2% in Prince William Sound, zero in Cook Inlet and reached 3.6% in the coastal waters of Kodiak Island. From there, prevalences declined southwesterly to 1.3% and zero along the Alaska Peninsula and the eastern Aleutian Islands. In the Bering Sea, the trend consisted of fluctuating low prevalences of BCS that increased by northerly latitudes in C, opilio, reaching the highest levels of 14.6 to 29.1% in Norton Sound and 13,3 to 15.5% in the Chukchi Sea/Arctic Ocean boundary area. The prevalences in C, bairdi from the eastern/northeastern Bering Sea were between zero and 2.4%. Prevalences of BCS from Russian waters in the western Bering Sea ranged from 0.9 and 1.1% in C. bairdi and C. opilio, respectively. Sample stations where equally large numbers of both Tanner crab species were examined suggested little difference in parasite prevalences. C1 NOAA,NATL MARINE FISHERIES SERV,RESOURCE ASSESSMENT & CONSERVAT ENGN DIV,SEATTLE,WA 98115. NATL PK SERV,GLACIER NATL PK,GUSTAVUS,AK 99826. ALASKA DEPT FISH & GAME,COMMERCIAL FISHERIES MANAGEMNT & DEV DIV,KODIAK,AK 99615. RP Meyers, TR (reprint author), ALASKA DEPT FISH & GAME,COMMERICAL FISHERIES MANAGEMENT & DEV DIV,FISH PATHOL SECT,POB 25526,JUNEAU,AK 99802, USA. NR 11 TC 22 Z9 27 U1 0 U2 1 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0177-5103 J9 DIS AQUAT ORGAN JI Dis. Aquat. Org. PD SEP 12 PY 1996 VL 26 IS 3 BP 221 EP 227 DI 10.3354/dao026221 PG 7 WC Fisheries; Veterinary Sciences SC Fisheries; Veterinary Sciences GA VN429 UT WOS:A1996VN42900008 ER PT J AU Hofmann, DJ AF Hofmann, DJ TI The 1996 Antarctic ozone hole SO NATURE LA English DT Letter ID QUASI-BIENNIAL OSCILLATION; LOWER STRATOSPHERE; SOUTH-POLE RP Hofmann, DJ (reprint author), NOAA,CLIMATE MONITORING & DIAGNOST LAB,325 BROADWAY,BOULDER,CO 80303, USA. NR 8 TC 11 Z9 11 U1 0 U2 0 PU MACMILLAN MAGAZINES LTD PI LONDON PA 4 LITTLE ESSEX STREET, LONDON, ENGLAND WC2R 3LF SN 0028-0836 J9 NATURE JI Nature PD SEP 12 PY 1996 VL 383 IS 6596 BP 129 EP 129 DI 10.1038/383129a0 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA VG148 UT WOS:A1996VG14800029 ER PT J AU Diaz, HF Graham, NE AF Diaz, HF Graham, NE TI Recent changes in tropical freezing heights and the role of sea surface temperature SO NATURE LA English DT Article ID GLOBAL TEMPERATURE; VARIABILITY; RETREAT; PACIFIC; PERU AB A WIDESPREAD retreat of alpine glaciers' and melting of tropical ice-cap margins(2-7) has been observed in recent decades, over which time a general climate warming at lower altitudes has been documented(8). Moreover, some ice-core records provide evidence suggesting that mid-tropospheric temperatures in the tropics have been greater in recent decades than at any time during the past 2,000-3,000 years(7). Here we examine the processes controlling mountain glacier retreat by comparing high-altitude air-temperature measurements for the past few decades, to the temperatures predicted by a model atmosphere forced by the observed global pattern of sea surface temperature in a 19-year simulation(9). The comparison strongly indicates that the observed changes in freezing-level height (the altitude of the 0 degrees C isotherm) are related to a long-term (over decades) increase in sea surface temperature in the tropics, and the consequent enhancement of the tropical hydrological cycle. Although changes in this cycle are likely to affect high-elevation hydrological and ecological balances worldwide(10,11), tropical environments may be particularly sensitive because the changes in tropical sea surface temperature and humidity may be largest and most systematic at low latitudes. C1 UNIV CALIF SAN DIEGO,SCRIPPS INST OCEANOG,DIV CLIMATE RES,LA JOLLA,CA 92093. RP Diaz, HF (reprint author), NOAA,ERL,CDC,325 BROADWAY,BOULDER,CO 80303, USA. NR 25 TC 106 Z9 114 U1 1 U2 11 PU MACMILLAN MAGAZINES LTD PI LONDON PA 4 LITTLE ESSEX STREET, LONDON, ENGLAND WC2R 3LF SN 0028-0836 J9 NATURE JI Nature PD SEP 12 PY 1996 VL 383 IS 6596 BP 152 EP 155 DI 10.1038/383152a0 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA VG148 UT WOS:A1996VG14800046 ER PT J AU Kim, J Massee, KC Hardy, RW AF Kim, J Massee, KC Hardy, RW TI Adult Artemia as food for first feeding coho salmon (Oncorhynchus kisutch) SO AQUACULTURE LA English DT Article DE first-feeding salmonids; Artemia; live food ID LIVE; WATER; PREY AB This study was conducted to determine if growth rates of first feeding coho fry, starting weight 0.34 g, were affected by substituting live food for commercially-prepared salmon fry feed. For 4 weeks, triplicate groups of fish were offered one of four diets: (1) live Artemia nauplii; (2) live adult Artemia; (3) a commercial starter pellet for salmon; and (4) a dry, pelleted Artemia diet composed mainly of freeze-dried nauplii. Groups of fish were fed either an excess or a restricted ration to determine if differences in growth were due to the nutritional content of the diet or to differences in feed intake. After 4 weeks, all groups of fish were switched to the commercial diet for an additional 2 week period to determine if any early benefits in weight gain were sustained when fish were switched to pelleted feed. The fry fed adult Artemia to excess grew significantly faster than coho fed the other test diets and this difference in size remained at 6 weeks of feeding, two weeks following the switch to a commercial diet. Fry fed restricted rations were similar in average length and weight. Increased growth in fry fed adult Artemia to excess was due to increased food intake. C1 NOAA,NATL MARINE FISHERIES SERV,NW FISHERIES SCI CTR,SEATTLE,WA 98112. NR 17 TC 25 Z9 31 U1 0 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0044-8486 J9 AQUACULTURE JI Aquaculture PD SEP 10 PY 1996 VL 144 IS 1-3 BP 217 EP 226 DI 10.1016/S0044-8486(96)01296-3 PG 10 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA VT392 UT WOS:A1996VT39200019 ER PT J AU Olinski, R Zastawny, TH Foksinski, M Windorbska, W Jaruga, P Dizdaroglu, M AF Olinski, R Zastawny, TH Foksinski, M Windorbska, W Jaruga, P Dizdaroglu, M TI DNA base damage in lymphocytes of cancer patients undergoing radiation therapy SO CANCER LETTERS LA English DT Article DE hydroxyl radical; DNA damage; DNA repair; modified DNA bases; free radicals ID ANTIOXIDANT ENZYME-ACTIVITIES; MAMMALIAN CHROMATIN; IONIZING-RADIATION; IN-VITRO; MUTAGENESIS; REPAIR; CELLS; RATS AB We investigated DNA base damage in genomic DNA of lymphocytes of cancer patients undergoing radiation therapy, Lymphocyte chromatin samples were analyzed by gas chromatography/isotope-dilution mass spectrometry for DNA base damage. The results provided evidence for formation of typical hydroxyl radical-induced base modifications in genomic DNA of lymphocytes. Different levels of DNA products in individuals were observed and, in the case of some patients, there was no significant product formation, possibly resulting from differences between individuals and between the types of radiation exposures. Decreases in product levels after an initial increase by radiation exposure were observed. This may indicate the removal of modified bases from lymphocyte DNA by cellular repair. C1 NIST,CHEM SCI & TECHNOL LAB,GAITHERSBURG,MD 20899. PROV CTR ONCOL,PL-85094 BYDGOSZCZ,POLAND. RP Olinski, R (reprint author), MED ACAD,DEPT CLIN BIOCHEM,PL-85094 BYDGOSZCZ,POLAND. RI Olinski, Ryszard/E-9607-2014; Foksinski, Marek/D-4942-2014; Jaruga, Pawel/M-4378-2015 OI Foksinski, Marek/0000-0002-1338-8230; NR 24 TC 30 Z9 30 U1 1 U2 1 PU ELSEVIER SCI IRELAND LTD PI CLARE PA CUSTOMER RELATIONS MANAGER, BAY 15, SHANNON INDUSTRIAL ESTATE CO, CLARE, IRELAND SN 0304-3835 J9 CANCER LETT JI Cancer Lett. PD SEP 10 PY 1996 VL 106 IS 2 BP 207 EP 215 DI 10.1016/0304-3835(96)04320-0 PG 9 WC Oncology SC Oncology GA VJ545 UT WOS:A1996VJ54500009 PM 8844974 ER PT J AU Ray, JR AF Ray, JR TI Measurements of length of day using the Global Positioning System SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID BASE-LINE INTERFEROMETRY; TIDAL VARIATIONS; ROTATION AB Length-of-day (LOD) estimates from the seven Global Positioning System (GPS) analysis centers of the International GPS Service for Geodynamics have been compared to values derived from very long baseline interferometry (VLBI) for a recent 16-month period. All GPS time series show significant LOD biases which vary widely among the centers. Within individual series the LOD errors show time-dependent correlations which are sometimes large and periodic. Clear correlations between ostensibly independent analyses are also evident. In the best case the GPS LOD errors, after bias removal, approach Gaussian with an intrinsic scatter estimated to be as small as similar to 21 mu s/d and a correlation time constant of perhaps 0.75 day. Integration of such data to determine variations in UT1 will have approximately random walk errors which grow as the square root of the integration time. For the current best GPS performance, UTI errors exceed those of daily 1-hour VLBI observations after integration for similar to 3 days. Assuming the stability of LOD biases can be reliably controlled, GPS-derived UT1 can be useful for near real time applications where otherwise extrapolations for several days from the most current VLBI data can be inaccurate by up to similar to 1 ms. RP Ray, JR (reprint author), NOAA, GEOSCI LAB, N-OES13, SSMC-4, 1305 E W HIGHWAY, SILVER SPRING, MD 20910 USA. NR 14 TC 16 Z9 18 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD SEP 10 PY 1996 VL 101 IS B9 BP 20141 EP 20149 DI 10.1029/96JB01889 PG 9 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA VG396 UT WOS:A1996VG39600010 ER PT J AU Lugez, CL Jacox, ME Thompson, WE AF Lugez, CL Jacox, ME Thompson, WE TI The vibrational spectra of molecular ions isolated in solid neon .13. Ions derived from HBr and HI SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ZERO-KINETIC-ENERGY; HIGH-RESOLUTION; INFRARED-SPECTRA; HYDROGEN IODIDE; ARGON MATRICES; NEGATIVE-IONS; SPECTROSCOPY; PHOTOIONIZATION; IONIZATION; STRENGTHS AB When a Ne:HBr or a Ne:HI sample is codeposited at approximately 5 K with discharge-excited neon atoms, the infrared spectrum of the resulting solid includes not only the absorptions of the HX molecule and its multimers but also a prominent absorption of HBr+ or HI+. The absorption of each of the two cations lies within a few cm(-1) of its gas-phase band center. The vibrational fundamentals of DBr+ and DI+ are also identified in experiments on deuterium-enriched samples. Other infrared absorptions are assigned to normal and deuterium-substituted (HBr)(2)(+) and (HI)(2)(+), as well as to BrHBr-, BrDBr-, and IHI-. Studies of changes in the absorption spectrum following exposure of the deposit to filtered visible and near ultraviolet radiation support these assignments and provide further information on photodissociation and photodetachment processes occurring in these systems. (C) 1996 American Institute of Physics. RP Lugez, CL (reprint author), NATL INST STAND & TECHNOL,OPT TECHNOL DIV,US DEPT COMMERCE,TECHNOL ADM,GAITHERSBURG,MD 20899, USA. NR 49 TC 14 Z9 14 U1 1 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 8 PY 1996 VL 105 IS 10 BP 3901 EP 3910 DI 10.1063/1.472262 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VF657 UT WOS:A1996VF65700001 ER PT J AU Shibayama, M Ikkai, F Inamoto, S Nomura, S Han, CC AF Shibayama, M Ikkai, F Inamoto, S Nomura, S Han, CC TI pH and salt concentration dependence of the microstructure of poly(N-isopropylacrylamide-co-acrylic acid) gels SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ANGLE NEUTRON-SCATTERING; VOLUME-PHASE-TRANSITION; N-ISOPROPYLACRYLAMIDE GELS; POLYMER GELS; COPOLYMER SOLUTIONS; TEMPERATURE AB The structure of environment-sensitive gels consisting of poly(N-isopropylacrylamide-co-acrylic acid) (NIPA/AAc) hydrogels was investigated by small-angle neutron scattering (SANS). Effects of the variation of ionic circumstance were observed both on the volume phase transition and on the structure factors: (1) The volume phase transition temperature, T-c, increases with increasing pH from 4 to 9 and then decreases with further increasing pH. (2) the volume gap between the shrunken and swollen gels at T-c is highest around pH 7 to 9. (3) Though the structure factor, I(q), has a maximum above the T-c of the corresponding NIPA homopolymer gels, the peak intensity decreases with increasing pH, where q is the magnitude of the scattering vector. When NaCl is added, a similar scattering maximum appears for T > T-c. However, strong ionic screening leads to a lower swelling power and a decrease in T-c, resulting in precipitation at a lower temperature than for the gel at a moderate pH. The roles of pH and salt are discussed on the basis of Donnan membrane equilibrium. (C) 1996 American Institute of Physics. C1 NIST,DIV POLYMER,GAITHERSBURG,MD 20899. RP Shibayama, M (reprint author), KYOTO INST TECHNOL,DEPT POLYMER SCI & ENGN,KYOTO 606,JAPAN. RI Shibayama, Mitsuhiro/E-1646-2015 OI Shibayama, Mitsuhiro/0000-0002-8683-5070 NR 21 TC 92 Z9 93 U1 1 U2 13 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 8 PY 1996 VL 105 IS 10 BP 4358 EP 4366 DI 10.1063/1.472252 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VF657 UT WOS:A1996VF65700046 ER PT J AU Zhang, KC Briggs, ME Gammon, RW Sengers, JMHL AF Zhang, KC Briggs, ME Gammon, RW Sengers, JMHL TI The susceptibility critical exponent for a nonaqueous ionic binary mixture near a consolute point (vol 97, pg 8692, 1992) SO JOURNAL OF CHEMICAL PHYSICS LA English DT Correction, Addition C1 US DEPT COMMERCE,NIST,CHEM SCI & TECHNOL LAB,PHYS & CHEM PROPERTIES DIV,GAITHERSBURG,MD 20899. RP Zhang, KC (reprint author), UNIV MARYLAND,INST PHYS SCI & TECHNOL,COLLEGE PK,MD 20742, USA. NR 1 TC 2 Z9 2 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 8 PY 1996 VL 105 IS 10 BP 4397 EP 4397 DI 10.1063/1.473015 PG 1 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VF657 UT WOS:A1996VF65700053 ER PT J AU Lagalante, AF Jacobson, RJ Bruno, TJ AF Lagalante, AF Jacobson, RJ Bruno, TJ TI UV/Vis spectroscopic evaluation of 4-nitropyridine N-oxide as a solvatochromic indicator for the hydrogen-bond donor ability of solvents SO JOURNAL OF ORGANIC CHEMISTRY LA English DT Article ID ORGANIC NONELECTROLYTES; SCALE; MIXTURES; WATER; DYES AB The potential of d-nitropyridine N-oxide to act as a solvatochromic indicator of the hydrogen-bond donor ability of solvents has been evaluated. A linear free-energy relationship has been established that is predominantly dependent on the Kamlet-Taft a parameter of the solvent. In comparison to the previously reported results obtained for pyridine N-oxide, 4-nitropyridine N-oxide possesses a solvatochromic effect that is located in the long wavelength ultraviolet region (lambda = 330-355 nm) of the spectrum, making it a viable probe for hydrogen-bond donation assessment. RP Lagalante, AF (reprint author), NATL INST STAND & TECHNOL,CHEM SCI & TECHNOL LAB,PHYS & CHEM PROPERTIES DIV,325 BROADWAY,BOULDER,CO 80303, USA. NR 16 TC 24 Z9 24 U1 1 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3263 J9 J ORG CHEM JI J. Org. Chem. PD SEP 6 PY 1996 VL 61 IS 18 BP 6404 EP 6406 DI 10.1021/jo9603688 PG 3 WC Chemistry, Organic SC Chemistry GA VG144 UT WOS:A1996VG14400051 ER PT J AU Zachariah, MR Carrier, MJ BlaistenBarojas, E AF Zachariah, MR Carrier, MJ BlaistenBarojas, E TI Properties of silicon nanoparticles: A molecular dynamics study SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID AMORPHOUS-SILICON; SI CLUSTERS; MICROCLUSTERS; SIMULATION; MODEL; STABILITY; SURFACE; BINDING; GE; SN AB Constant energy molecular dynamics simulations of silicon cluster growth have been conducted for clusters up to 480 atoms using the Stillinger-Weber empirical interatomic potential. It is found that the interior atoms of the 480-atom clusters, at the temperatures used, show bulklike characteristics. The cluster binding energy has been fit to an expression that separates the surface and bulk contributions to the energy over wide temperatures and size ranges. The average surface energy of an atom was found to be independent of cluster size and of a magnitude relative to the bulk, such that ail cluster sizes were stable under the conditions studied here (600 < T < 2000 K). The photon density of states is similar to bulk silicon and does not show a strong cluster size dependence. Atomic self-diffusion coefficients have been calculated and compare quite well with experimental data on self-diffusion coefficient measurements of silicon surfaces. C1 GEORGE MASON UNIV,INST COMP & INFORMAT SCI,FAIRFAX,VA 22030. RP Zachariah, MR (reprint author), NIST,GAITHERSBURG,MD 20899, USA. RI Blaisten-Barojas, Estela/B-9520-2009 NR 46 TC 53 Z9 54 U1 2 U2 20 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD SEP 5 PY 1996 VL 100 IS 36 BP 14856 EP 14864 DI 10.1021/jp953773w PG 9 WC Chemistry, Physical SC Chemistry GA VF665 UT WOS:A1996VF66500003 ER PT J AU Krishnamurthy, M deGouw, JA Bierbaum, VM Leone, SR AF Krishnamurthy, M deGouw, JA Bierbaum, VM Leone, SR TI Mobilities of aromatic ions drifting in helium SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID BENZENE DIMER CATION; GAS-PHASE; CLUSTER IONS; ATOMS; ENERGY; CHROMATOGRAPHY; DISSOCIATION; REACTIVITY; GEOMETRY; TUBE AB Aromatic ions are produced in an electron impact ion source and injected into the flow tube section of a selected-ion flow-drift tube (SIFDT) apparatus. The reduced mobilities of C6H5+, C6H6+, C6H7+, C12H12+ C12H11+, naphthalene (C10H8+) cation, and biphenyl (C12H10+) cation drifting in helium are measured as a function of the characteristic parameter E/N (the ratio of the electric field to the number density of the helium buffer gas atoms in the drift tube). The reduced mobilities of the benzene dimer ions (C12H12+ and C12H11+) are compared with the measured mobilities of naphthalene and biphenyl cations to correlate the mobilities with ionic structures. An angle-averaged collision cross section of the ions drifting in helium is obtained from the geometric structure of these ions and is used to compute the zero-field mobility. The predicted zero-field mobilities are found to compare well with the experimentally measured mobilities. C1 UNIV COLORADO,NIST,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. UNIV COLORADO,DEPT CHEM & BIOCHEM,DEPT PHYS,BOULDER,CO 80309. RI de Gouw, Joost/A-9675-2008 OI de Gouw, Joost/0000-0002-0385-1826 NR 36 TC 21 Z9 21 U1 0 U2 11 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD SEP 5 PY 1996 VL 100 IS 36 BP 14908 EP 14913 DI 10.1021/jp960159r PG 6 WC Chemistry, Physical SC Chemistry GA VF665 UT WOS:A1996VF66500010 ER PT J AU Pittman, TB Strekalov, DV Migdall, A Rubin, MH Sergienko, AV Shih, YH AF Pittman, TB Strekalov, DV Migdall, A Rubin, MH Sergienko, AV Shih, YH TI Can two-photon interference be considered the interference of two photons? SO PHYSICAL REVIEW LETTERS LA English DT Article ID QUANTUM ERASER; DISPERSION CANCELLATION; CONVERSION AB We report on a ''postponed compensation'' experiment in which the observed two-photon entangled state interference cannot be pictured in terms of the overlap of the two individual photon wave packets of a parametric down-conversion pair on a beam splitter. In the sense of a quantum eraser, the distinguishability of the different two-photon Feynman amplitudes leading to a coincidence detection is removed by delaying the compensation until after the output of an unbalanced two-photon interferometer. C1 NATL INST STAND & TECHNOL,RADIOMETR PHYS DIV,GAITHERSBURG,MD 20899. RP Pittman, TB (reprint author), UNIV MARYLAND,DEPT PHYS,BALTIMORE,MD 21228, USA. RI Pittman, Todd/M-4686-2013 NR 15 TC 130 Z9 130 U1 2 U2 10 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 2 PY 1996 VL 77 IS 10 BP 1917 EP 1920 DI 10.1103/PhysRevLett.77.1917 PG 4 WC Physics, Multidisciplinary SC Physics GA VE351 UT WOS:A1996VE35100002 ER PT J AU Snyder, K AF Snyder, K TI Influence of measurement technique on the air-void structure of hardened concrete. SO ACI MATERIALS JOURNAL LA English DT Editorial Material RP Snyder, K (reprint author), NATL INST STAND & TECHNOL,DIV BLDG MAT,GAITHERSBURG,MD 20899, USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU AMER CONCRETE INST PI FARMINGTON HILLS PA 38800 INTERNATIONAL WAY, COUNTRY CLUB DRIVE, PO BOX 9094, FARMINGTON HILLS, MI 48333-9094 SN 0889-325X J9 ACI MATER J JI ACI Mater. J. PD SEP-OCT PY 1996 VL 93 IS 5 BP 512 EP 514 PG 3 WC Construction & Building Technology; Materials Science, Multidisciplinary SC Construction & Building Technology; Materials Science GA VM687 UT WOS:A1996VM68700021 ER PT J AU Oldham, NM AF Oldham, NM TI Overview of bioelectrical impedance analyzers SO AMERICAN JOURNAL OF CLINICAL NUTRITION LA English DT Article; Proceedings Paper CT National-Institutes-of-Health-Technology-Assessment Conference on Bioelectrical Impedance Analysis in Body Composition Measurement CY DEC 12-14, 1994 CL BETHESDA, MD SP NIDDKD, NIH, Off Med Applicat Res, NICHHD, NIA, NHLBI, USDA DE bioelectrical impedance analysis; BIA; body composition; bioelectrical impedance analyzer; impedance ID HUMAN-BODY AB Six commercial bioelectrical impedance analyzers were evaluated to determine their accuracy as impedance meters, their sensitivity to contact impedance, and other operating parameters such as maximum current amplitude and test waveform. Over a range of impedances that simulate human body impedance, analyzer errors varied from < 1% to nearly 20%. Larger errors were observed when the contact impedance was at the limits of the operating range of the analyzer. Body models, sources of error, and several simple tests that the user can perform are also discussed. RP NIST, DIV ELECT, US DEPT COMMERCE, TECHNOL ADM, GAITHERSBURG, MD 20899 USA. NR 9 TC 11 Z9 12 U1 1 U2 1 PU AMER SOC NUTRITION-ASN PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 USA SN 0002-9165 EI 1938-3207 J9 AM J CLIN NUTR JI Am. J. Clin. Nutr. PD SEP PY 1996 VL 64 IS 3 SU S BP 405 EP 412 PG 8 WC Nutrition & Dietetics SC Nutrition & Dietetics GA VE984 UT WOS:A1996VE98400004 ER PT J AU Inn, KGW Lin, ZV Liggett, WS Schima, FJ Krey, P Feiner, M Liu, CK Holloway, R Harvey, J Larsen, IL Beasley, T Huh, CA McCurdy, D Germain, P Yamamoto, M Handl, J Popplewell, DS Woods, MJ Jerome, S Bates, TH Holms, A Harvey, BR Odell, KJ Warren, BB Young, P AF Inn, KGW Lin, ZV Liggett, WS Schima, FJ Krey, P Feiner, M Liu, CK Holloway, R Harvey, J Larsen, IL Beasley, T Huh, CA McCurdy, D Germain, P Yamamoto, M Handl, J Popplewell, DS Woods, MJ Jerome, S Bates, TH Holms, A Harvey, BR Odell, KJ Warren, BB Young, P TI Low-level radioactivity ocean sediment standard reference material SO APPLIED RADIATION AND ISOTOPES LA English DT Article; Proceedings Paper CT International-Committee-for-Radionuclide-Metrology Conference on Low-Level Measurement Techniques CY OCT 02-06, 1995 CL SEVILLE, SPAIN SP Int Comm Radionuclide Metrol AB The National Institute of Standards and Technology (NIST), in cooperation with experienced international laboratories, will issue a low-level radioactivity Ocean Sediment Standard Reference Material (SRM) 4357 in 1996. The Ocean Sediment joins the NIST suite of six other 'natural matrix' environmental radioactivity Standard Reference Materials. This family of natural matrix materials have already been used: (1) to develop radiochemical procedures; (2) to test radiochemical procedures already in use for environmental and biokinetic evaluations; (3) to calibrate instruments; (4) to intercompare and evaluate radiochemical methods; (5) to test competency of technicians to do radiochemical assays; and (6) to demonstrate that data output is reliable. The participating laboratories provided data for the following 25 radionuclides: K-40, Sr-90, (TC)-T-99, I-129, (CS)-C-137, Eu-155, Pb-210, Po-210, Pb-212, Bi-214, Ra-226, Ra-228, Ac-228, Th-228, Th-230, Th-232, U-234, U-235, Np-237, U-238, Pu-238, Pu-239+Pu-240, Pu-241, and Am-241. The data for many of these radionuclides are of sufficient quality to establish certified values and reasonable uncertainty limits given the relatively low concentrations of the radionuclides. The uncertainties for a number of certified radionuclides are non-symmetrical and large because of the non-normal distribution of reported values. Copyright (C) 1996 Elsevier Science Ltd. C1 NATL INST STAND & TECHNOL,STAT ENGN DIV,COMP & APPL MATH LAB,TECHNOL ADM,US DEPT COMMERCE,GAITHERSBURG,MD 20899. US EPA,LAS VEGAS,NV 89193. US DOE,ENVIRONM MEASUREMENTS LAB,NEW YORK,NY 10014. INT TECHNOL CORP,OAK RIDGE,TN. MARTIN MARIETTA ENERGY SYST INC,OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. OREGON STATE UNIV,NEWPORT,OR. YANKEE ATOM ELECT CO,BOLTON,ENGLAND. CEA,CTR STUDIES NUCL,LAB RADIOECOL MARINE,FONTENAY ROSES,FRANCE. KANAZAWA UNIV,KANAZAWA,ISHIKAWA 920,JAPAN. NIEDERSACHS INST RADIOOKOL,HANNOVER,GERMANY. NATL RADIOL PROTECT BOARD,OXFORD,ENGLAND. NATL PHYS LAB,TEDDINGTON TW11 0LW,MIDDX,ENGLAND. BRITISH NUCL FUELS PLC,SELLAFIELD,ENGLAND. LAB GOVT CHEMIST,TEDDINGTON TW11 0LY,MIDDX,ENGLAND. MAFF,LOWESTOFT NR33 OHT,SUFFOLK,ENGLAND. NUCL ELECT,GRAVESEND,ENGLAND. ATOM WEAPONS ESTAB,ALDERMASTON,ENGLAND. S SCOTLAND ELECT BOARD,HUNTERSTON,SCOTLAND. RP Inn, KGW (reprint author), NATL INST STAND & TECHNOL,IONIZING RADIAT DIV,PHYS LAB,TECHNOL ADM,US DEPT COMMERCE,GAITHERSBURG,MD 20899, USA. RI Huh, Chih-An/N-4610-2013 NR 1 TC 8 Z9 8 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0969-8043 J9 APPL RADIAT ISOTOPES JI Appl. Radiat. Isot. PD SEP-OCT PY 1996 VL 47 IS 9-10 BP 967 EP 970 DI 10.1016/S0969-8043(96)00094-2 PG 4 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Chemistry; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA VX653 UT WOS:A1996VX65300027 ER PT J AU Cheng, YT Soodprasert, T Hutchinson, JMR AF Cheng, YT Soodprasert, T Hutchinson, JMR TI Radioactivity measurements using storage phosphor technology SO APPLIED RADIATION AND ISOTOPES LA English DT Article; Proceedings Paper CT International-Committee-for-Radionuclide-Metrology Conference on Low-Level Measurement Techniques CY OCT 02-06, 1995 CL SEVILLE, SPAIN SP Int Comm Radionuclide Metrol AB The response of a storage photostimulable phosphor imager (SPP) system has been studied using alpha- and beta-particle point sources, large area sources and with environmental soil samples previously characterized for radionuclide content. Alpha radiation can be easily differentiated from other radiations. Furthermore, for thin sources, alpha-particle emitting radionuclides can be differentiated from each other. A number of other response characteristics of the system are also described. Copyright (C) 1996 Elsevier Science Ltd C1 OFF ATOM ENERGY PEACE,RADIAT MEASUREMENT DIV,CHATUCHAK,THAILAND. NIST,IONIZING RADIAT DIV,PHYS LAB,TECHNOL ADM,US DEPT COMMERCE,GAITHERSBURG,MD 20899. RP Cheng, YT (reprint author), NEUTEK,13537 SCOTTISH AUTUMN LANE,DARNESTOWN,MD 20878, USA. NR 6 TC 10 Z9 10 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0969-8043 J9 APPL RADIAT ISOTOPES JI Appl. Radiat. Isot. PD SEP-OCT PY 1996 VL 47 IS 9-10 BP 1023 EP 1031 DI 10.1016/S0969-8043(96)00101-7 PG 9 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Chemistry; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA VX653 UT WOS:A1996VX65300034 ER PT J AU Epperly, SP Braun, J Chester, AJ Cross, FA Merriner, JV Tester, PA Churchill, JH AF Epperly, SP Braun, J Chester, AJ Cross, FA Merriner, JV Tester, PA Churchill, JH TI Beach strandings as an indicator of at-sea mortality of sea turtles SO BULLETIN OF MARINE SCIENCE LA English DT Article ID SOUTH-ATLANTIC BIGHT; GULF-STREAM; CONTINENTAL-SHELF; NORTH-CAROLINA; CAPE-HATTERAS; UNITED-STATES; SLOPE WATERS; WIND; ENTRAINMENT; CIRCULATION AB Estimates of the number of federally protected sea turtles drowned during the 1991-1992 winter trawl fishery for summer flounder off North Carolina were compared to the number of turtles stranded on beaches adjacent to the fishing grounds. The objective was to evaluate how well beach strandings functioned as an indicator of fishery-induced mortality. The number of dead turtles that washed up on the beaches represented a maximum of 7-13% of the estimated fishery-induced mortalities. We attribute this discrepancy to offshore bottom currents, which normally transport lifeless turtles away from the beach during the winter. We conclude that turtle strandings during the winter on the northern beaches of North Carolina are a poor indicator of at-sea mortalities, and that they may not be entirely related to the winter trawl fishery for summer flounder. C1 WOODS HOLE OCEANOG INST,WOODS HOLE,MA 02543. RP Epperly, SP (reprint author), NOAA,NATL MARINE FISHERIES SERV,SE FISHERIES SCI CTR,BEAUFORT LAB,BEAUFORT,NC 28516, USA. NR 28 TC 58 Z9 70 U1 1 U2 7 PU ROSENSTIEL SCH MAR ATMOS SCI PI MIAMI PA 4600 RICKENBACKER CAUSEWAY, MIAMI, FL 33149 SN 0007-4977 J9 B MAR SCI JI Bull. Mar. Sci. PD SEP PY 1996 VL 59 IS 2 BP 289 EP 297 PG 9 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA VF672 UT WOS:A1996VF67200004 ER PT J AU Sellers, PJ Meeson, BW Closs, J Collatz, J Corprew, F Dazlich, D Hall, FG Kerr, Y Koster, R Los, S Mitchell, K McManus, J Myers, D Sun, KJ Try, P AF Sellers, PJ Meeson, BW Closs, J Collatz, J Corprew, F Dazlich, D Hall, FG Kerr, Y Koster, R Los, S Mitchell, K McManus, J Myers, D Sun, KJ Try, P TI The ISLSCP initiative I global datasets: Surface boundary conditions and atmospheric forcings for land-atmosphere studies SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID SIMPLE BIOSPHERE MODEL; DATA SET; CLIMATE; ALGORITHMS; BUDGET AB A comprehensive series of global datasets for land-atmosphere models has been collected, formatted to a common grid, and released on a set of CD-ROMs. This paper describes the motivation for and the contents of the dataset. In June of 1992, an interdisciplinary earth science workshop was convened in Columbia, Maryland, to assess progress in land-atmosphere research, specifically in the areas of models, satellite data algorithms, and field experiments. At the workshop, representatives of the land-atmosphere modeling community defined a need for global datasets to prescribe boundary conditions, initialize state variables, and provide near-surface meteorological and radiative forcings for their models. The International Satellite Land Surface Climatology Project (ISLSCP), a part of the Global Energy and Water Cycle Experiment, worked with the Distributed Active Archive Center of the National Aeronautics and Space Administration Goddard Space Flight Center to bring the required datasets together in a usable format. The data have since been released on a collection of CD-ROMs. The datasets on the CD-ROMs are grouped under the following headings: vegetation; hydrology and soils; snow, ice, and oceans; radiation and clouds; and near-surface meteorology. All datasets cover the period 1987-88, and all but a few are spatially continuous over the earth's land surface. All have been mapped to a common 1 degrees x 1 degrees equal-angle grid. The temporal frequency for most of the datasets is monthly. A few of the near-surface meteorological parameters are available both as six-hourly values and as monthly means. C1 NASA,GODDARD SPACE FLIGHT CTR,DAAC,GREENBELT,MD 20771. NASA,GODDARD SPACE FLIGHT CTR,HSTX,GREENBELT,MD 20771. COLORADO STATE UNIV,DEPT ATMOSPHER SCI,FT COLLINS,CO 80523. LERTS,BPI,TOULOUSE,FRANCE. NASA,GSFC,SSAI,GREENBELT,MD. NOAA,NMC,CAMP SPRINGS,MD. INT GEWEX PROJECT OFF,WASHINGTON,DC. RI collatz, george/D-5381-2012; Koster, Randal/F-5881-2012; Los, Sietse/G-8985-2012; zhong, honglin/C-2633-2012; OI Koster, Randal/0000-0001-6418-6383; Los, Sietse/0000-0002-1325-3555 NR 26 TC 81 Z9 81 U1 0 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD SEP PY 1996 VL 77 IS 9 BP 1987 EP 2005 DI 10.1175/1520-0477(1996)077<1987:TIIIGD>2.0.CO;2 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VL660 UT WOS:A1996VL66000003 ER PT J AU Livezey, RE Tinker, R AF Livezey, RE Tinker, R TI Some meteorological, climatological, and microclimatological considerations of the severe US heat wave of mid-July 1995 SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article AB Various aspects of the severe heat wave that affected the midwestern and eastern United States in mid-July 1995 and led to hundreds of heat-related deaths are examined. First, the event is placed in historical context through examination of relatively long records at several affected sites. Next, the origins of both the strong high pressure cell and the unusually large moisture content of the air mass are traced. This is followed by a brief summary that concludes with the suggestion that longer-term processes played minor roles at best in the event. Finally, microclimatic factors in the Chicago metropolitan area are considered for their role in exacerbating conditions in the city most severely affected by the heat wave. RP Livezey, RE (reprint author), NOAA,CLIMATE PREDICT CTR,NCEP,NWS,SCI CTR,WP51,ROOM 604,5200 AUTH RD,CAMP SPRINGS,MD 20746, USA. NR 2 TC 23 Z9 23 U1 1 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD SEP PY 1996 VL 77 IS 9 BP 2043 EP 2054 DI 10.1175/1520-0477(1996)077<2043:SMCAMC>2.0.CO;2 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VL660 UT WOS:A1996VL66000006 ER PT J AU Lewis, JM Moore, CB AF Lewis, JM Moore, CB TI Meisinger log recovered SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Letter C1 NEW MEXICO INST MIN & TECHNOL,SOCORRO,NM 87801. RP Lewis, JM (reprint author), NOAA,ERL,NATL SEVERE STORMS LAB,NORMAN,OK 73069, USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD SEP PY 1996 VL 77 IS 9 BP 2106 EP 2110 PG 5 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VL660 UT WOS:A1996VL66000012 ER PT J AU Brodeur, RD Wilson, MT AF Brodeur, RD Wilson, MT TI Mesoscale acoustic patterns of juvenile walleye pollock (Theragra chalcogramma) in the western Gulf of Alaska SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID VERTICAL-DISTRIBUTION; TARGET STRENGTH; ABUNDANCE INDEXES; SCHOOLING FISH; GEORGES-BANK; BERING SEA; HADDOCK; LARVAL; COD; THERMOCLINES AB The mesoscale distribution patterns of age-0 walleye pollock (Theragra chalcogramma) in the western Gulf of Alaska were assessed through a combined acoustic and midwater trawl survey in 1990. Using a 38-kHz split-beam acoustic system and directed midwater trawling, we were able to isolate concentrations of scatterers that were mainly age-0 pollock based on the expected target strength (-45 to -53 dB) derived from an empirical relationship of target strength Versus length. The concentrations of these scatterers formed diffuse layers that were centered at a depth of 33 m during the night. During the day, scatterers descended to a depth of ca 100 m (up to 30 m off the bottom) where they coalesced into tight aggregations. A sharp thermocline did not inhibit the diel migration of these juveniles. Higher concentrations were found in inner shelf regions as compared with inshore bays or offshore waters, but the varied topography appeared to have little effect on the distribution of these juveniles. These results are discussed in relation to the trophic position of these fish as both predators and prey in this system. RP Brodeur, RD (reprint author), NOAA,NATL MARINE FISHERIES SERV,ALASKA FISHERIES SCI CTR,7600 SAND POINT WAY NE,BIN C15700,SEATTLE,WA 98115, USA. NR 45 TC 34 Z9 36 U1 0 U2 4 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA ON K1A 0R6, CANADA SN 0706-652X J9 CAN J FISH AQUAT SCI JI Can. J. Fish. Aquat. Sci. PD SEP PY 1996 VL 53 IS 9 BP 1951 EP 1963 DI 10.1139/cjfas-53-9-1951 PG 13 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA WE259 UT WOS:A1996WE25900004 ER PT J AU Cavaletto, JF Nalepa, TF Dermott, R Gardner, WS Quigley, MA Lang, GA AF Cavaletto, JF Nalepa, TF Dermott, R Gardner, WS Quigley, MA Lang, GA TI Seasonal variation of lipid composition weight, and length in juvenile Diporeia spp (Amphipoda) from lakes Michigan and Ontario SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID PONTOPOREIA-HOYI; MONOPOREIA-AFFINIS; DISTRIBUTIONS; MACROBENTHOS; POPULATIONS; COMMUNITIES; ZOOPLANKTON; NEARSHORE; ECOLOGY; TRENDS AB Benthic amphipods, Diporeia spp., were collected during 1988 and 1989 at four sites to compare size and Lipid levels of animals living in Lakes Michigan and Ontario: sites were at depths of 45 and 100 m in Lake Michigan and 35 and 125 m in Lake Ontario. In Lake Michigan, the mean length, mass, and Lipid levels of individual Diporeia from 45 m were significantly different from those collected from 100 m in 1988, in 1989, only mass and Lipid levels were significantly different between depths. In contrast, regardless of the year, the Lake Ontario Diporeia from 35 m were similar in mass and length to those from 125 m, but lipid levels were significantly different between depths. Combined means for total lipid for each lake over similar months revealed higher levels in Lake Ontario than in Lake Michigan Diporeia. Triacylglycerols were the dominant Lipid class in all the amphipods, with mean levels reaching a maximum of 84% of the total lipid in individuals from Lake Ontario at 35 m. Trophic state, food-web, and (or) genetic differences are probably responsible for the occurrence of higher lipid levels in Lake Ontario Diporeia than in Lake Michigan Diporeia. C1 FISHERIES & OCEANS CANADA, GREAT LAKES LAB FISHERIES & AQUAT SCI, CANADA CTR INLAND WATERS, BURLINGTON, ON L7R 4A6, CANADA. RP Cavaletto, JF (reprint author), NOAA, GREAT LAKES ENVIRONM RES LAB, 2205 COMMONWEALTH BLVD, ANN ARBOR, MI 48105 USA. NR 38 TC 23 Z9 24 U1 2 U2 6 PU CANADIAN SCIENCE PUBLISHING, NRC RESEARCH PRESS PI OTTAWA PA 1200 MONTREAL ROAD, BUILDING M-55, OTTAWA, ON K1A 0R6, CANADA SN 0706-652X J9 CAN J FISH AQUAT SCI JI Can. J. Fish. Aquat. Sci. PD SEP PY 1996 VL 53 IS 9 BP 2044 EP 2051 DI 10.1139/cjfas-53-9-2044 PG 8 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA WE259 UT WOS:A1996WE25900012 ER PT J AU Marks, RE Juanes, F Hare, JA Conover, DO AF Marks, RE Juanes, F Hare, JA Conover, DO TI Occurrence and effect of the parasitic isopod, Lironeca ovalis (Isopoda: Cymothoidae), on young-of-the-year bluefish, Pomatomus saltatrix (Pisces: Pomatomidae) SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID GROWTH AB The bluefish, Pomatomus saltatrix, is often a preferred host for infection by the isopod, gill ectoparasite Lironeca ovalis. Here we quantify the occurrence of infection by L. ovalis on young-of-the-year bluefish in the Hudson River estuary and evaluate whether there is a significant reduction in growth or foraging as a result of infection. Prevalence of L. ovalis on bluefish was high (25.4%) but small (<75 mm) and large fish (>175 mm) exhibited significantly lower prevalences than intermediate-sized fish. Parasite size increased with bluefish size, and a significant but small effect of parasitism on the bluefish mass-length relationship was found; parasitized fish weighed 3% less than nonparasitized fish at a given length. Infection did not have a significant effect on the mass of stomach contents at capture. Although there remain many questions regarding the host-parasite relationship between P. saltatrix and L. ovalis, the physiological cost associated with infection appears to be small and probably does not constitute a serious threat to individual bluefish survival. C1 N CAROLINA DEPT ENVIRONM HLTH & NAT RESOURCES,DIV MARINE FISHERIES,MANTEO,NC 27954. UNIV MASSACHUSETTS,DEPT FORESTRY & WILDLIFE MANAGEMENT,AMHERST,MA 01003. NOAA,NATL MARINE FISHERIES SERV,BEAUFORT LAB,BEAUFORT,NC 28516. SUNY STONY BROOK,MARINE SCI RES CTR,STONY BROOK,NY 11794. NR 37 TC 17 Z9 18 U1 0 U2 7 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA ON K1A 0R6, CANADA SN 0706-652X J9 CAN J FISH AQUAT SCI JI Can. J. Fish. Aquat. Sci. PD SEP PY 1996 VL 53 IS 9 BP 2052 EP 2057 DI 10.1139/cjfas-53-9-2052 PG 6 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA WE259 UT WOS:A1996WE25900013 ER PT J AU Ferrero, RC Walker, WA AF Ferrero, RC Walker, WA TI Age, growth, and reproductive patterns of the Pacific white-sided dolphin (Lagenorhynchus obliquidens) taken in high seas drift nets in the central North Pacific Ocean SO CANADIAN JOURNAL OF ZOOLOGY-REVUE CANADIENNE DE ZOOLOGIE LA English DT Article ID EASTERN TROPICAL PACIFIC; STENELLA-ATTENUATA; OFFSHORE WATERS AB Biological data were collected from 341 Pacific white-sided dolphins (Lagenorhynchus obliquidens; 171 males and 170 females) taken in high seas drift nets in the central North Pacific Ocean in June-September of 1990 and 1991. Age was determined for 149 dolphins (73 males and 76 females) by counting dentinal growth layer groups and measuring postnatal dentine thickness. Reproductive status was determined for 76 females and 71 males. Ten females were sexually mature (3 pregnant and 7 lactating), as were 11 males. The estimated average length at birth was 91.8 cm (SE = 0.4787 cm; n = 4). The estimated gestation period was 11-12 months. The sex ratio was not significantly different from 1:1. The youngest sexually mature male was 10 years of age and the oldest sexually immature male 11 years. The youngest sexually mature female was 8.3 years of age and the oldest sexually immature female 11 years. The average length at sexual maturation was 173.7 cm (SE = 0.8953 cm) for males and 177.5 cm (SE = 1.5 cm) for females. Males and females reached an estimated asymptotic length of 184 and 177 cm, respectively. Estimates of early postnatal growth rates were complicated by poor growth model fit; however, both sexes appeared to grow about 4.5 cm/month during the first half year. A calving period preceded sampling during late winter and spring. RP Ferrero, RC (reprint author), NOAA,NATL MARINE FISHERIES SERV,ALASKA FISHERIES SCI CTR,NATL MARINE MAMMAL LAB,SEATTLE,WA 98115, USA. NR 48 TC 17 Z9 18 U1 1 U2 4 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA ON K1A 0R6, CANADA SN 0008-4301 J9 CAN J ZOOL JI Can. J. Zool.-Rev. Can. Zool. PD SEP PY 1996 VL 74 IS 9 BP 1673 EP 1687 DI 10.1139/z96-185 PG 15 WC Zoology SC Zoology GA VG773 UT WOS:A1996VG77300010 ER PT J AU Mammen, M Helmerson, K Kishore, R Choi, SK Phillips, WD Whitesides, GM AF Mammen, M Helmerson, K Kishore, R Choi, SK Phillips, WD Whitesides, GM TI Optically controlled collisions of biological objects to evaluate potent polyvalent inhibitors of virus-cell adhesion SO CHEMISTRY & BIOLOGY LA English DT Article DE adhesion probability; erythrocyte; influenza; optical tweezers; polyvalent inhibitor ID INFLUENZA-VIRUS; FORCE; MANIPULATION; RECEPTOR; MOLECULE; TWEEZERS; BINDING; LASER AB Background: The biochemical and biomechanical determinants of adhesion between two biological objects following a collision are complex, and may vary from one system to another. We wished to develop an assay in which all the relevant factors, including the components of the solution, the relative orientation and the relative collision velocity, are under the user's control. Results: A new assay is described in which two mesoscale particles are caused to collide using two independently controlled optical tweezers (optically controlled collision, OPTCOL), This assay enables precise examination of the probability of adhesion under biologically relevant conditions, The OPTCOL assay was used to evaluate the probability of adhesion of a single erythrocyte to a single virus-coated microsphere, in the absence and presence of a sialic acid-bearing inhibitor, Inhibition constants for the most effective inhibitors could not be measured using other types of assays, The best inhibitor prevented attachment 50 % of the time at a sialic acid concentration of 35 pmol l(-1); it is the most potent known inhibitor of attachment of influenza virus to erythrocytes. Conclusions: OPTCOL is a versatile new bioassay for studying dynamic interactions in biochemistry. It offers an approach to investigating interactions between moving biological objects that is both quantitative and interpretable. The simplicity of the OPTCOL technique suggests broad applicability to the study of adhesion of mesoscale (1-100 mu m) objects in the areas of cell biology, microbiology, medicinal chemistry, and biophysics. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. HARVARD UNIV,DEPT CHEM & CHEM BIOL,CAMBRIDGE,MA 02138. RI Helmerson, Kristian/E-3683-2013; OI Choi, Seok Ki/0000-0001-5633-4817 FU NIGMS NIH HHS [GM 30367] NR 21 TC 41 Z9 41 U1 2 U2 8 PU CURRENT BIOLOGY LTD PI LONDON PA 34-42 CLEVELAND STREET, LONDON, ENGLAND W1P 6LB SN 1074-5521 J9 CHEM BIOL JI Chem. Biol. PD SEP PY 1996 VL 3 IS 9 BP 757 EP 763 DI 10.1016/S1074-5521(96)90252-5 PG 7 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA VM928 UT WOS:A1996VM92800008 PM 8939692 ER PT J AU McGrattan, KB Kashiwagi, T Baum, HR Olson, SL AF McGrattan, KB Kashiwagi, T Baum, HR Olson, SL TI Effects of ignition and wind on the transition to flame spread in a microgravity environment SO COMBUSTION AND FLAME LA English DT Article ID FUEL; MODEL; FEEDBACK; SURFACE; FLOW AB A two-dimensional time-dependent model is developed describing ignition and the subsequent transition to flame spread over a thermally thin cellulosic sheet heated by external radiation in a microgravity environment. The effects of a slow external wind (0-5 cm/s), and of the flux distribution of the external radiation on the transition are studied mainly in an atmosphere of 30% oxygen concentration. The ignition is initiated along the width of a sample strip, giving rise initially to two flame fronts spreading in opposite directions. The calculated results are compared with data obtained in the 2.2-s drop tower. Both experimental and calculated results show that with a slow, imposed wind, the upstream flame front (opposed mode) is stronger and slightly faster than the quiescent counterpart due to a greater supply of oxygen. However, the downstream flame front (concurrent mode) tends to die during the transition period. For all calculated cases studied in this work using the selected kinetic constants for the global one-step gas phase reaction, the downstream flame front dies out in oxygen concentrations up to 50% and wind velocity up to 5 cm/s. This is caused by the ''oxygen shadow'' cast by the upstream flame. The ignition delay time depends mainly on the peak flux of external radiation, whereas the transition time to steady state flame spread depends mainly on the broadness of the flux distribution. The broader the radiative flux distribution, the greater the transient flame spread rate due to the preheating of the sample ahead of the flame front by the external radiation and thus the greater the delay to steady state flame spread. C1 NASA,LEWIS RES CTR,CLEVELAND,OH 44135. RP McGrattan, KB (reprint author), NATL INST STAND & TECHNOL,BLDG & FIRE RES LAB,ROOM A-345,BLDG 224,GAITHERSBURG,MD 20899, USA. NR 20 TC 30 Z9 34 U1 1 U2 4 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 0010-2180 J9 COMBUST FLAME JI Combust. Flame PD SEP PY 1996 VL 106 IS 4 BP 377 EP & DI 10.1016/0010-2180(96)00184-8 PG 16 WC Thermodynamics; Energy & Fuels; Engineering, Multidisciplinary; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA VE509 UT WOS:A1996VE50900002 ER PT J AU Kaplan, CR Shaddix, CR Smyth, KC AF Kaplan, CR Shaddix, CR Smyth, KC TI Computations of enhanced soot production in time-varying CH4/air diffusion flames SO COMBUSTION AND FLAME LA English DT Article ID QUANTITATIVE MEASUREMENTS; LAMINAR; GROWTH; TRANSPORT; DYNAMICS; RATES AB Recent experimental measurements of soot volume fraction in a flickering CH4/air diffusion flame show that for conditions in which the tip of the flame is clipped, soot production is similar to 5 times greater than that measured for a steady flame burning with the same mean fuel flow velocity (Shaddix et al., Ref. 9). This paper presents time-dependent numerical simulations of both steady and time-varying CH4/air diffusion flames to examine the differences in combustion conditions which lead to the observed enhancement in soot production in the flickering flames. The numerical model solves the two-dimensional, time-dependent, reactive-flow Navier-Stokes equations coupled with submodels for soot formation and radiation transport. Qualitative comparisons between the experimental and computed steady flame show good agreement for the soot burnout height and overall flame shape except near the burner lip. Quantitative comparisons between experimental and computed radial profiles of temperature and soot volume fraction for the steady flame show good to excellent agreement at mid-flame heights, but some discrepancies neat the burner lip and at high flame heights. For the time-varying CH4/air flame, the simulations successfully predict that the maximum soot concentration increases by over four times compared to the steady flame with the same mean fuel and air velocities. By numerically tracking fluid parcels in the flowfield, the temperature and stoichiometry history were followed along their convective pathlines. Results for the pathline which passes through the maximum sooting region show that flickering flames exhibit much longer residence times during which the local temperatures and stoichiometries are favorable for soot production. The simulations also suggest that soot inception occurs later in flickering flames, and at slightly higher temperatures and under somewhat leaner conditions compared to the steady flame. The integrated soot model of Syed et al. (Ref. 12), which was developed from a steady CH4/air flame, successfully predicts soot production in the time-varying CH4/air flames. C1 NATL INST STAND & TECHNOL,BLDG & FIRE RES LAB,GAITHERSBURG,MD 20899. RP Kaplan, CR (reprint author), USN,RES LAB,COMPUTAT PHYS & FLUID DYNAM LAB,WASHINGTON,DC 20375, USA. NR 41 TC 75 Z9 75 U1 1 U2 5 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 0010-2180 J9 COMBUST FLAME JI Combust. Flame PD SEP PY 1996 VL 106 IS 4 BP 392 EP 405 DI 10.1016/0010-2180(95)00258-8 PG 16 WC Thermodynamics; Energy & Fuels; Engineering, Multidisciplinary; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA VE509 UT WOS:A1996VE50900003 ER PT J AU Skrtic, D Antonucci, JM Eanes, ED AF Skrtic, D Antonucci, JM Eanes, ED TI Improved properties of amorphous calcium phosphate fillers in remineralizing resin composites SO DENTAL MATERIALS LA English DT Article ID CEMENTS AB Objectives. The rationale for this study was based on the hypothesis that the mechanical strength of methacrylate composites containing the bioactive filler, amorphous calcium phosphate, can be enhanced by synthesizing this filler in the presence of glass-forming agents. Specifically this study was conducted to prepare composites with zirconia- and silica-modified amorphous calcium phosphate fillers, and to determine whether the remineralization potential from the release of calcium and phosphate ions and the mechanical properties of the corresponding methacrylate composites were enhanced. Methods. The modified amorphous calcium phosphates were synthesized at pH 10.5 by mixing 800 mmol/L Ca(NO3)(2) solutions and either 250 mmol/L zirconyl chloride (ZrOCl2) or 4.4 mol/L tetraethoxysilane (TEOS) solutions with solutions containing 525 mmol/L Na2HPO4 and 11 mmol/L Na4P2O7. After washing and drying, the amorphous calcium phosphates were mixed with visible light-activated resins and photopolymerized to form composite disks that were then examined for their ability to release Ca2+ and total ionic phosphate (PO43- + HPO42- + H2PO4, hereafter indicated as PO4) by immersion in HEPES-buffered (pH 7.4) saline at 37 degrees C. Solution ion concentrations were compared at regular intervals up to 265 h. Biaxial flexural strengths of the composites before and after immersion were compared, and significant differences were established by Student's t test (p < 0.05). Results. Both ZrOCl2- and TEOS-modified amorphous calcium phosphate composite disks released Ca2+ and PO4 ions at sustained levels requisite for remineralization to occur. The transformation of amorphous calcium phosphate into hydroxyapatite within the composites was also retarded, particularly in the case of amorphous calcium phosphate modified with ZrOCl2. Biaxial flexure strength values of composite disks showed that TEOS- and ZrOCl2-amorphous calcium phosphate-filled composites increased in strength by 33% and 21% before immersion and by 25% and 27% after immersion, respectively, compared to unmodified amorphous calcium phosphate composites (controls). All strength increases except TEOS after immersion were significant (p<0.05). Significance. Properly modified amorphous calcium phosphate fillers can be used to prepare bioactive composites with enhanced mechanical properties for more demanding dental applications without compromising their remineralizing potential. C1 NIDR,RES ASSOCIATE PROGRAM,BETHESDA,MD 20892. NATL INST STAND & TECHNOL,DENT & MED MAT GRP,DIV POLYMER,GAITHERSBURG,MD 20899. NR 26 TC 72 Z9 75 U1 1 U2 15 PU ACAD DENTAL MATERIALS PI DALLAS PA BAYLOR COLLEGE DENTISTRY, 3302 GASTON AVE, DALLAS, TX 75266-0677 SN 0109-5641 J9 DENT MATER JI Dent. Mater. PD SEP-NOV PY 1996 VL 12 IS 5-6 BP 295 EP 301 DI 10.1016/S0109-5641(96)80037-6 PG 7 WC Dentistry, Oral Surgery & Medicine; Materials Science, Biomaterials SC Dentistry, Oral Surgery & Medicine; Materials Science GA WB402 UT WOS:A1996WB40200002 PM 9170997 ER PT J AU Kenworthy, WJ Fonseca, MS AF Kenworthy, WJ Fonseca, MS TI Light requirements of seagrasses Halodule wrightii and Syringodium filiforme derived from the relationship between diffuse light attenuation and maximum depth distribution SO ESTUARIES LA English DT Article ID ZOSTERA-MARINA EELGRASS; THALASSIA-TESTUDINUM; GROWTH; PHOTOSYNTHESIS; FLORIDA; LAGOON; WATER; PRODUCTIVITY; IRRADIANCE; METABOLISM AB The correspondence between maximum depth of growth (Z(max)) for two seagrases, Halodule wrightii and Syringodium filiforme, and the attenuation of diffuse photosynthetically active radiation (K(d)PAR) were evaluated over a 3.5-yr period in the southern Indian River Lagoon, Florida. The lower limit of seagrass depth distribution was controlled by light availability. Both species grew to the same maximum depth, indicating they have similar minimum light requirements. Based on average annual values of K(d)PAR, estimates of seagrass maximum light requirements ranged from 24% to 37% of the light just beneath the water surface (I-0), much higher than a photic zone for many phytoplankton and macroalgae (1-5% incident light). In less transparent waters of Hobe Sound, where turbidity (NTU) and color (Pt-Co) had their highest concentrations, minimum light requirements for growth were greatest. These results suggest that more sophisticated optical models are needed to identify specific water quality constituents affecting the light environment of seagrasses. Water quality criteria and standard needed to protect seagrasses from decreasing water transparency must be based on parameters that can be routinely and reasonably managed. RP Kenworthy, WJ (reprint author), NOAA,NATL MARINE FISHERIES SERV,SE FISHERIES SCI CTR,BEAUFORT LAB,BEAUFORT,NC 28516, USA. NR 60 TC 67 Z9 71 U1 2 U2 19 PU ESTUARINE RES FEDERATION PI LAWRENCE PA PO BOX 368, LAWRENCE, KS 66044 SN 0160-8347 J9 ESTUARIES JI Estuaries PD SEP PY 1996 VL 19 IS 3 BP 740 EP 750 DI 10.2307/1352533 PG 11 WC Environmental Sciences; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA VP806 UT WOS:A1996VP80600021 ER PT J AU Bohnsack, JA AF Bohnsack, JA TI Marine reserves, zoning, and the future of fishery management SO FISHERIES LA English DT Article ID RESOURCE RP Bohnsack, JA (reprint author), SE FISHERIES CTR,NATL MARINE FISHERIES SERV,MIAMI LAB,75 VIRGINA BEACH DR,MIAMI,FL 33149, USA. NR 14 TC 42 Z9 43 U1 0 U2 5 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE SUITE 110, BETHESDA, MD 20814-2199 SN 0363-2415 J9 FISHERIES JI Fisheries PD SEP PY 1996 VL 21 IS 9 BP 14 EP 16 PG 3 WC Fisheries SC Fisheries GA VF361 UT WOS:A1996VF36100004 ER PT J AU Thomas, JBR Kline, MC Schiller, SB Ellerbe, PM Sniegoski, LT Duewer, DL Sharpless, KE AF Thomas, JBR Kline, MC Schiller, SB Ellerbe, PM Sniegoski, LT Duewer, DL Sharpless, KE TI Certification of fat soluble vitamins, carotenoids, and cholesterol in human serum: Standard reference material 968b SO FRESENIUS JOURNAL OF ANALYTICAL CHEMISTRY LA English DT Article ID QUANTITATIVE-DETERMINATION; LIQUID-CHROMATOGRAPHY; DEFINITIVE METHOD; ALPHA-TOCOPHEROL; BETA-CAROTENE; RETINOL; PLASMA; ISOMERS; STORAGE AB In Standard Reference Material 968b, fat-soluble vitamins and cholesterol in human serum, certified values are provided for cholesterol, retinol, retinyl palmitate, alpha-tocopherol, trans-beta-carotene, total beta-carotene (trans plus cis isomers), total alpha-carotene, and lutein. Non-certified values are also reported for gamma-tocopherol (includes beta-tocopherol), delta-tocopherol, zeaxanthin, beta-cryptoxanthin, trans-lycopene, trans-lycopene, trans-alpha-carotene, total lycopene, 9-cis-beta-carotene, 13-plus 15-cis-beta-carotene, and 15-cis-beta-carotene. Both certified and non-certified values are based on the agreement among results from three different liquid chromatographic analytical procedures developed at NIST and from an interlaboratory comparison exercise among institutions that participate in a NIST-managed Micronutrients Measurement Quality Assurance Program. Cholesterol is certified in this material using the NIST isotope dilution/mass spectrometric definitive method. C1 NIST,DIV BIOTECHNOL,GAITHERSBURG,MD 20899. NIST,STAT ENGN DIV,GAITHERSBURG,MD 20899. RP Thomas, JBR (reprint author), NIST,CTR ANALYT CHEM,GAITHERSBURG,MD 20899, USA. RI Duewer, David/B-7410-2008; OI Sharpless, Katherine/0000-0001-6569-198X NR 26 TC 14 Z9 14 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0937-0633 J9 FRESEN J ANAL CHEM JI Fresenius J. Anal. Chem. PD SEP PY 1996 VL 356 IS 1 BP 1 EP 9 PG 9 WC Chemistry, Analytical SC Chemistry GA VC973 UT WOS:A1996VC97300001 ER PT J AU MacKinnon, DJ Chavez, PS Fraser, RS Niemeyer, TC Gillette, DA AF MacKinnon, DJ Chavez, PS Fraser, RS Niemeyer, TC Gillette, DA TI Calibration of GOES-VISSR, visible-band satellite data and its application to the analysis of a dust storm at Owens lake, California SO GEOMORPHOLOGY LA English DT Article ID ATMOSPHERIC DUST; SCATTERING; AEROSOLS; IMAGES; INDEX AB As part of a joint Russian/American dust-storm experiment, GOES-VISSR (Geostationary Operational Environmental Satellite, Visible-Infrared Spin-Scan Radiometer), data from a visible-band satellite image of a large dust storm emanating from Owens Lake, California were acquired on March 10 and 11, 1993. The satellite data were calibrated to targets of known ground reflectance factors and processed with radiative transfer techniques to yield aerosol (dust) optical depth at those stages of the dust storm when concurrent ground-based measurements of optical depth were made. Calibration of the satellite data is crucial for comparing surficial changes in remotely sensed data acquired over a period of time from the same area and for determining accurate concentrations of atmospheric aerosols using radiative transfer techniques. The calibration procedure forces the distribution of visible-band, DN (digital number) values, acquired on July 1, 1992, at 1731 GMT from the GOES-VISSR sensor over a large test area, to match the distribution of visible-band, DN values concurrently acquired from a Landsat MSS (Multispectral Scanner) sensor over the same test area; the Landsat MSS DN values were directly associated with reflectance factors measured from ground targets. The calibrated GOES-VISSR data for July 1, 1992, were then used to calibrate other GOES-VISSR data acquired on March 10 and 11, 1993, during the dust storm, Uncertainties in location of ground targets, bi-directional reflectance and atmospheric attenuation contribute an error of approximately +/-0.02 in the satellite-inferred ground reflectance factors. On March 11 at 1031 PST the satellite-received radiances during the peak of the storm were 3 times larger than predicted by our radiative transfer model for a pure clay dust plume of infinite optical depth. This result supported ground-based measurements that the plume at that time was composed primarily of large salt grains, probably sodium sulfate, which could not be properly characterized in our radiative transfer model. Further, the satellite data showed that the salt fell out of the plume within 35 km from the source. Finer-grained, clay dust was observed to extend beyond the salt-laden plume and was the major component of the dust plume after 1131 PST, when erosion of the salt crust on Owens Lake ceased. By 1331 and 1401 PST satellite-inferred, optical depths compared favorably with measurements concurrently acquired at the ground. Uncertainties in bi-directional reflectance, atmospheric attenuation, and locating ground points in the satellite data manifest errors between the inferred and measured optical depths in the range of 20 to 50%; these errors would be much greater without the calibration of the GOES-VISSR data. Changes in satellite-inferred reflectance factors over the lake bed during the course of the storm showed that 76 km(2) of the surface was disrupted during the March 11 storm, suggesting as much as 76 x 10(3) m(3) of crustal material were displaced for each millimeter of several estimated to have been moved during the storm; an unknown fraction of the displaced material was suspended. The satellite data also showed dust fallout on mountain snowfields. Whereas fallout may have removed most of the salt, satellite data acquired at 1631 PST, when the plume had a large brightness contrast with the ground, showed that it covered over 2500 km(2) and contained at least 1.6 x 10(9) g of sediment. For such a small source area, the dust represents a substantial contribution to the regional and global load of aerosols. C1 NASA, GODDARD SPACE FLIGHT CTR, GREENBELT, MD 20771 USA. ENVIRONM CONSULTING, SWANSEA, CA USA. NOAA, RES TRIANGLE PK, NC USA. RP US GEOL SURVEY, FLAGSTAFF, AZ 86001 USA. NR 25 TC 7 Z9 7 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-555X EI 1872-695X J9 GEOMORPHOLOGY JI Geomorphology PD SEP PY 1996 VL 17 IS 1-3 BP 229 EP 248 DI 10.1016/0169-555X(95)00105-E PG 20 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA VE330 UT WOS:A1996VE33000017 ER PT J AU Langford, AO Masters, CD Proffitt, MH Hsie, EY Tuck, AF AF Langford, AO Masters, CD Proffitt, MH Hsie, EY Tuck, AF TI Ozone measurements in a tropopause fold associated with a cut-off low system SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID STRATOSPHERE-TROPOSPHERE EXCHANGE AB The two-dimensional structure of a tropopause fold that formed on the western flank of a cut-off cyclone over the western United States is examined through time series of vertical ozone profiles made using the NOAA Aeronomy Laboratory's Differential Absorption Lidar (DIAL) system at Fritz Peak Observatory (39.9 degrees N, 105.3 degrees W, 2.68 km above sea level). The observations are compared to calculated potential vorticity fields, and the net influx of ozone to the troposphere is estimated to be similar to 5.5 x 10(32) molecules assuming that the fold is irreversibly mixed into the troposphere below 8.5 km. C1 UNIV COLORADO,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. NOAA,AERON LAB,BOULDER,CO 80309. RI Langford, Andrew/D-2323-2009; Tuck, Adrian/F-6024-2011; Hsie, Eirh-Yu/I-4449-2013 OI Langford, Andrew/0000-0002-2932-7061; Tuck, Adrian/0000-0002-2074-0538; Hsie, Eirh-Yu/0000-0003-3934-9923 NR 15 TC 43 Z9 44 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD SEP 1 PY 1996 VL 23 IS 18 BP 2501 EP 2504 DI 10.1029/96GL02227 PG 4 WC Geosciences, Multidisciplinary SC Geology GA VG005 UT WOS:A1996VG00500023 ER PT J AU Odstrcil, D Smith, Z Dryer, M AF Odstrcil, D Smith, Z Dryer, M TI Distortion of the heliospheric plasma sheet by interplanetary shocks SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID GEOMAGNETIC STORMS; DEFORMATION AB A 2 1/2D MHD model is used to investigate mutual interactions between interplanetary shocks with the interplanetary magnetic field (IMF). An ambient solar wind is considered with a flat equatorial heliospheric current sheet (HCS) that is embedded within a finite thickness heliospheric plasma sheet (HPS). Two different velocity pulses are introduced with four different latitudinal positions at 0.1 AU. We found that large values of the meridional IMF originate when the shock interacts with the HPS. This is caused by field-line draping around the highly distorted shock driver and by deflection of the HCS in asymmetric Situations. C1 INST ASTRON,ONDREJOV 25165,CZECH REPUBLIC. UNIV COLORADO,CIRES,BOULDER,CO 80309. RP Odstrcil, D (reprint author), NOAA,SPACE ENVIRONM CTR,325 BROADWAY,BOULDER,CO 80303, USA. RI xue, yansheng/A-9712-2012 NR 10 TC 18 Z9 18 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD SEP 1 PY 1996 VL 23 IS 18 BP 2521 EP 2524 DI 10.1029/96GL00159 PG 4 WC Geosciences, Multidisciplinary SC Geology GA VG005 UT WOS:A1996VG00500028 ER PT J AU Birnbaum, G Borysow, A Orton, GS AF Birnbaum, G Borysow, A Orton, GS TI Collision-induced absorption of H-2-H-2 and H-2-He in the rotational and fundamental bands for planetary applications SO ICARUS LA English DT Article ID INDUCED ROTOTRANSLATIONAL SPECTRA; PRESSURE-INDUCED ABSORPTION; INDUCED INFRARED-ABSORPTION; MOLECULAR-HYDROGEN; HELIUM ABUNDANCE; VOYAGER MEASUREMENTS; THERMAL STRUCTURE; OUTER PLANETS; H2-H2 PAIRS; TEMPERATURES AB In recent years there has been significant progress in the ab initio computation and modeling of the collision-induced absorption in H-2-H-2 and H-2-He pairs in the rotovibrational and purely rototranslational bands covering 0-6000 cm(-1) at temperatures from 40 to 300 K. Extensive experimental and theoretical results have been obtained in a number of laboratories regarding this absorption as a function of frequency and temperature. This report summarizes the most advanced literature on this subject and presents a number of new results. Moreover, this report is designed to facilitate the utilization of this knowledge for the study of planetary atmospheres, and for future research of the H-2-H-2 and H-2-He infrared spectra. The theoretical absorption coefficients arising from free-free transitions in collisional pairs are available in the form of FORTRAN programs which permit rapid and reliable evaluation of spectral intensities even for frequencies and temperatures at which laboratory measurements do not exist. The various approximations affecting the accuracy of the theory applied here are discussed in some detail. The theoretical spectra closely duplicate the existing laboratory measurements of collision-induced absorption, whose accuracy is discussed; only for the case of the fundamental band of H-2-He are there small discrepancies from recent measurements which exceed somewhat the combined uncertainties of theory and measurement. The simple analytical functions on which these computer programs are based have also been compared with the quantum mechanical computations of the spectra and very close agreement has been observed. Notes regarding the use of the computer programs and sample outputs are given to serve as a test for their applications. (C) 1996 Academic Press, Inc. C1 MICHIGAN TECHNOL UNIV, DEPT PHYS, HOUGHTON, MI 49931 USA. CALTECH, JET PROP LAB, DIV EARTH & SPACE SCI, PASADENA, CA 91109 USA. RP Birnbaum, G (reprint author), NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. NR 64 TC 56 Z9 56 U1 0 U2 5 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0019-1035 J9 ICARUS JI Icarus PD SEP PY 1996 VL 123 IS 1 BP 4 EP 22 DI 10.1006/icar.1996.0138 PG 19 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VN300 UT WOS:A1996VN30000002 ER PT J AU Beichl, I Sullivan, F AF Beichl, I Sullivan, F TI Making connections SO IEEE COMPUTATIONAL SCIENCE & ENGINEERING LA English DT Editorial Material C1 IDA CTR COMP SCI,BOWIE,MD. RP Beichl, I (reprint author), NIST,COMP & APPL MATH LAB,GAITHERSBURG,MD 20899, USA. NR 0 TC 4 Z9 4 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 SN 1070-9924 J9 IEEE COMPUT SCI ENG JI IEEE Comput. Sci. Eng. PD FAL PY 1996 VL 3 IS 3 BP 9 EP 12 DI 10.1109/99.537087 PG 4 WC Computer Science, Theory & Methods; Engineering, Electrical & Electronic; Mathematics, Applied SC Computer Science; Engineering; Mathematics GA VH235 UT WOS:A1996VH23500003 ER PT J AU Rice, JR Boisvert, RF AF Rice, JR Boisvert, RF TI From scientific software libraries to problem solving environments SO IEEE COMPUTATIONAL SCIENCE & ENGINEERING LA English DT Article C1 NATL INST STAND & TECHNOL,MATH SOFTWARE GRP,BOULDER,CO 80303. RP Rice, JR (reprint author), PURDUE UNIV,DEPT COMP SCI,W LAFAYETTE,IN 47907, USA. OI Boisvert, Ronald/0000-0002-4445-1044 NR 4 TC 54 Z9 56 U1 0 U2 1 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 SN 1070-9924 J9 IEEE COMPUT SCI ENG JI IEEE Comput. Sci. Eng. PD FAL PY 1996 VL 3 IS 3 BP 44 EP 53 DI 10.1109/99.537091 PG 10 WC Computer Science, Theory & Methods; Engineering, Electrical & Electronic; Mathematics, Applied SC Computer Science; Engineering; Mathematics GA VH235 UT WOS:A1996VH23500007 ER PT J AU Huang, XR Cheung, SK Cartwright, AN Smirl, AL Tseng, WF AF Huang, XR Cheung, SK Cartwright, AN Smirl, AL Tseng, WF TI An interdigitated stacked p-i-n multiple-quantum-well modulator SO IEEE PHOTONICS TECHNOLOGY LETTERS LA English DT Article ID MOLECULAR-BEAM EPITAXY; SHADOW MASK; DOPING SUPERLATTICES; ELECTROABSORPTION; CONTACTS; REGROWTH AB We demonstrate low-voltage operation of a strained InGaAs-GaAs interdigitated hetero n-i-p-i modulator (or stacked SEED) that is grown and fabricated using a shadow-mask growth technique for making the metal contacts to the n- and p-layers separately, An absorption change of 6 x 10(3) cm(-1) with an applied bias as low as similar to 1 V is observed in an unoptimized structure, Optical switching of the unbiased structure is also demonstrated. C1 NIST,DIV SEMICOND ELECT,GAITHERSBURG,MD 20899. RP Huang, XR (reprint author), UNIV IOWA,LAB PHOTON & QUANTUM ELECT,IOWA CITY,IA 52242, USA. RI Cartwright, Alexander/C-4380-2008 OI Cartwright, Alexander/0000-0002-0921-8036 NR 13 TC 2 Z9 2 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1041-1135 J9 IEEE PHOTONIC TECH L JI IEEE Photonics Technol. Lett. PD SEP PY 1996 VL 8 IS 9 BP 1172 EP 1174 DI 10.1109/68.531826 PG 3 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA VE155 UT WOS:A1996VE15500020 ER PT J AU Rice, P Hoinville, JR AF Rice, P Hoinville, JR TI Spatial correlation between magnetic force microscope images and recording head output SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 1996 IEEE International Magnetics Conference (INTERMAG 96) CY APR 09-12, 1996 CL SEATTLE, WA SP IEEE AB We have developed a technique which directly compares magnetic force microscope (MFM) images and recording head read-back signals on longitudinal thin-film disks with exact spatial correlation. To get exact spatial correlation we had to perform three important operations at the same position on the disk. We wrote data with an inductive recording head; we read-back the data with the same head; and we imaged the data with an MFM. Using this technique we show that MFM images are related directly to the read-back signal. As one of the examples of this technique, we saw a signal anomaly which could have been mistaken for media noise which from the MFM image was proven to be incomplete overwrite. C1 MAXTOR CORP,LONGMONT,CO 80501. RP Rice, P (reprint author), NATL INST STAND & TECHNOL,325 BROADWAY,BOULDER,CO 80303, USA. NR 4 TC 10 Z9 10 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD SEP PY 1996 VL 32 IS 5 BP 3563 EP 3565 DI 10.1109/20.538690 PN 1 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA VM258 UT WOS:A1996VM25800066 ER PT J AU Crawford, TM Rogers, CT Silva, TJ Kim, YK AF Crawford, TM Rogers, CT Silva, TJ Kim, YK TI Transverse and longitudinal second-harmonic magneto-optic Kerr effect observed from Ni81Fe19 thin film structures SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 1996 IEEE International Magnetics Conference (INTERMAG 96) CY APR 09-12, 1996 CL SEATTLE, WA SP IEEE ID 2ND-HARMONIC GENERATION; MULTILAYERS AB We report measurements of the second-harmonic magneto-optic Kerr effect in both transverse and longitudinal geometries from 100-nm-thick Ni81Fe19 films. For the transverse geometry, we observe intensity changes of roughly a factor of 3 upon magnetization reversal. In the longitudinal geometry, the second harmonic Kerr angle is 32.6 degrees for s-incidence and 6.8 degrees for p-incidence. A simple theoretical treatment allows us to compare the relevant second-order susceptibility elements as measured in the two geometries: the element magnitudes and relative phase shifts agree within experimental error. C1 NATL INST STAND & TECHNOL,BOULDER,CO 80303. QUANTUM PERIPHERALS COLORADO INC,LOUISVILLE,CO 80028. RP Crawford, TM (reprint author), UNIV COLORADO,DEPT PHYS,CONDENSED MATTER LAB,BOULDER,CO 80309, USA. RI Silva, Thomas/C-7605-2013 OI Silva, Thomas/0000-0001-8164-9642 NR 10 TC 11 Z9 11 U1 0 U2 6 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD SEP PY 1996 VL 32 IS 5 BP 4087 EP 4089 DI 10.1109/20.539272 PN 1 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA VM258 UT WOS:A1996VM25800235 ER PT J AU Rochford, KB Rose, AH Day, GW AF Rochford, KB Rose, AH Day, GW TI Magneto-optic sensors based on iron garnets SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 1996 IEEE International Magnetics Conference (INTERMAG 96) CY APR 09-12, 1996 CL SEATTLE, WA SP IEEE ID FIELD SENSORS; IMPROVED SENSITIVITY; INTERFEROMETER AB The use of single crystal bulk and film iron garnets in optical sensors is reviewed. Magneto-optic sensitivity and its stability are important parameters that depend on a variety of factors, including optical design. Polarimetric and diffractive sensor technologies are summarized, and several recent demonstrations of magnetic field, current, and rotation sensing using garnets are described. Garnets also find application as important nonsensing components in sensor systems. RP Rochford, KB (reprint author), NATL INST STAND & TECHNOL,DIV OPTOELECT,325 BROADWAY,BOULDER,CO 80303, USA. NR 24 TC 26 Z9 26 U1 1 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD SEP PY 1996 VL 32 IS 5 BP 4113 EP 4117 DI 10.1109/20.539314 PN 1 PG 5 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA VM258 UT WOS:A1996VM25800242 ER PT J AU Rice, P Russek, SE Haines, B AF Rice, P Russek, SE Haines, B TI Magnetic imaging reference sample SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 1996 IEEE International Magnetics Conference (INTERMAG 96) CY APR 09-12, 1996 CL SEATTLE, WA SP IEEE ID FORCE MICROSCOPY; TIPS AB We propose a reference sample for magnetic imaging. We have chosen a thin-film magnetic hard disk as a representative sample because the domains are very stable magnetically and thermally. This type of sample is also of fundamental interest to the disk drive industry, currently the largest user of magnetic force microscopy. Disk samples are prepared by writing a special magnetic pattern consisting of various transition spacings designed to explore certain aspects of magnetic imaging. Disks are then cut into coupons, cleaned and patterned with a reference grid of numbered 20 mu m x 20 mu m Au frames. These frames allow easy navigation around the sample. We believe a sample of this type can help define limits, expectations and claims of resolution, as well as instrument sensitivity and ease of operation. C1 MAXTOR CORP,LONGMONT,CO 80501. RP Rice, P (reprint author), NATL INST STAND & TECHNOL,325 BROADWAY,BOULDER,CO 80303, USA. NR 20 TC 14 Z9 14 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD SEP PY 1996 VL 32 IS 5 BP 4133 EP 4137 DI 10.1109/20.539318 PN 1 PG 5 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA VM258 UT WOS:A1996VM25800246 ER PT J AU Mizuseki, H Ishihara, M Hu, X Kawazoe, Y Ohta, N AF Mizuseki, H Ishihara, M Hu, X Kawazoe, Y Ohta, N TI Magnetic multi-valued recording by new magnetic configurations in 2D and 3D artificial lattices SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 1996 IEEE International Magnetics Conference (INTERMAG 96) CY APR 09-12, 1996 CL SEATTLE, WA SP IEEE AB New magnetic configurations in 2D and 3D artificial lattices are studied by solving the non-linear equation based on the classical Heisenberg models for 2D and 3D artificial lattices. The results indicate strong possibility to be used as an ultra-high density magnetic recording media achieved by magnetic multi-valued (MMV) recording. The MMV states are based on the magnetic anisotropic configurations in 2D and 3D artificial lattices. In this paper, the magnetic properties of these artificial lattices and the density of MMV recording are discussed. C1 NATL INST STAND & TECHNOL,BOULDER,CO 80303. HITACHI MAXELL LTD,ENGN RES LAB,YAWARA,IBARAKI 30024,JAPAN. RP Mizuseki, H (reprint author), TOHOKU UNIV,INST MAT RES,2-1-1 KATAHIRA,SENDAI,MIYAGI 98077,JAPAN. RI Kawazoe, Yoshiyuki/C-2998-2011; Mizuseki, Hiroshi/A-8891-2011 OI Mizuseki, Hiroshi/0000-0003-0973-7693 NR 5 TC 7 Z9 7 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD SEP PY 1996 VL 32 IS 5 BP 4335 EP 4337 DI 10.1109/20.538861 PN 2 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA VM259 UT WOS:A1996VM25900021 ER PT J AU Bennett, LH Vajda, F Atzmony, U Swartzendruber, LJ AF Bennett, LH Vajda, F Atzmony, U Swartzendruber, LJ TI Accommodation study of a nanograin iron powder SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 1996 IEEE International Magnetics Conference (INTERMAG 96) CY APR 09-12, 1996 CL SEATTLE, WA SP IEEE ID PARTICULATE SYSTEMS; REPTATION AB Accommodation (reptation) is a magnetizing process which occurs when the field is cycled between two extrema. The resulting minor loops do not close upon themselves, but rather approach a closed limit cycle with each application of the applied field extrema. This paper shows that there is significant accommodation in an evaporated nanograin iron powder. The shape of the accommodating loops depends on the applied field extrema. C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. NUCL RES CTR NEGEV,IL-84190 BEER SHEVA,ISRAEL. RP Bennett, LH (reprint author), GEORGE WASHINGTON UNIV,INST MAGNET RES,ASHBURN,VA 22011, USA. NR 10 TC 15 Z9 15 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD SEP PY 1996 VL 32 IS 5 BP 4493 EP 4495 DI 10.1109/20.538908 PN 2 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA VM259 UT WOS:A1996VM25900068 ER PT J AU Hu, X Kawazoe, Y AF Hu, X Kawazoe, Y TI Surface anisotropy and spin-reorientation transitions in ultrathin magnetic films SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 1996 IEEE International Magnetics Conference (INTERMAG 96) CY APR 09-12, 1996 CL SEATTLE, WA SP IEEE ID INPLANE MAGNETIZATION; STATIC MAGNETIZATION; COBALT FILMS; THIN-FILMS; MONOLAYER; DOMAINS; FE(100); SYSTEMS; LAYERS AB A micromagnetic theory is presented for spin-reorientation transitions in ultrathin magnetic films with normal surface anisotropy. Both discrete and continuum models are investigated and coincidence is found between the results derived from them. Two continuous transitions in spin orientation, from uniform and normal to canting, and then to uniform and in-plane, are observed as the film thickness is increased. The effects of higher-order terms in the expansions of the anisotropies compared to the dominant terms are also considered. A method for evaluating the surface anisotropy is formulated. The relation between the present micromagnetic theory and the phenomenological theory is discussed. C1 NATL INST STAND & TECHNOL,BOULDER,CO 80303. TOHOKU UNIV,INST MAT RES,SENDAI,MIYAGI 98077,JAPAN. RI Kawazoe, Yoshiyuki/C-2998-2011 NR 31 TC 2 Z9 2 U1 1 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD SEP PY 1996 VL 32 IS 5 BP 4561 EP 4566 DI 10.1109/20.539080 PN 2 PG 6 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA VM259 UT WOS:A1996VM25900090 ER PT J AU Oti, JO Cross, RW Russek, SE Kim, YK AF Oti, JO Cross, RW Russek, SE Kim, YK TI Simulated magnetoresistive behavior of geometrically asymmetric spin valves SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 1996 IEEE International Magnetics Conference (INTERMAG 96) CY APR 09-12, 1996 CL SEATTLE, WA SP IEEE AB A semi-analytical micromagnetic model is used to study how the magnetoresistive (MR) response is affected by uneven geometries in NiFe/Cu/NiFe spin-valve devices. Devices with unequal stripe heights and thicknesses of the magnetic layers are studied. The calculated devices are 4 inn long, pinned by a transverse field of 16 kA/m and have nonmagnetic spacer thicknesses of 4 nm. Stripe heights are varied from 0.5 mu m to 2 mu m and magnetic-layer thicknesses from 3 nm to 6 nm. Device responses are analyzed and used to indicate how optimal device geometries may be selected. C1 QUANTUM PERIPHERALS COLORADO INC,LOUISVILLE,CO 80028. RP Oti, JO (reprint author), NATL INST STAND & TECHNOL,DIV ELECTROMAGNET TECHNOL,BOULDER,CO 80303, USA. NR 3 TC 1 Z9 1 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD SEP PY 1996 VL 32 IS 5 BP 4606 EP 4608 DI 10.1109/20.539093 PN 2 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA VM259 UT WOS:A1996VM25900103 ER PT J AU Oti, JO Kim, YK Shand, PM AF Oti, JO Kim, YK Shand, PM TI Identifying phenomenological magnetoresistive properties of spin valves SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 1996 IEEE International Magnetics Conference (INTERMAG 96) CY APR 09-12, 1996 CL SEATTLE, WA SP IEEE AB A methodology for identifying essential magnetoresistive parameters of spin valves is presented. The method uses a formulation of the magnetoresistance of a magnetic layer that incorporates the magnetic and transport properties of the device in a phenomenological way. Experimental data are used in conjunction with the formulation to obtain magnetoresistive parameters. The method is shown to accurately characterize a set of NiFe/Cu/NiFe spin-valve devices. C1 QUANTUM PERIPHERALS COLORADO INC,LOUISVILLE,CO 80028. UNIV NO IOWA,DEPT PHYS,CEDAR FALLS,IA 50614. RP Oti, JO (reprint author), NATL INST STAND & TECHNOL,DIV ELECTROMAGNET TECHNOL,BOULDER,CO 80303, USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD SEP PY 1996 VL 32 IS 5 BP 4609 EP 4611 DI 10.1109/20.539094 PN 2 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA VM259 UT WOS:A1996VM25900104 ER PT J AU McMichael, RD Watanabe, T Dura, JA Borchers, JA Chen, PJ Brown, HJ Egelhoff, WF AF McMichael, RD Watanabe, T Dura, JA Borchers, JA Chen, PJ Brown, HJ Egelhoff, WF TI Origins of coercivity increase in annealed symmetric spin valves SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 1996 IEEE International Magnetics Conference (INTERMAG 96) CY APR 09-12, 1996 CL SEATTLE, WA SP IEEE ID MAGNETORESISTANCE AB Measurements of the effects of annealing on symmetric Co/Cu spin valves and similar structures show increased coercivity, increased ferromagnetic resonance linewidth and reduced moment. Low angle x-ray reflectivity measurements indicate that there is some oxidation throughout the thickness of the metal films during annealing. The layer structure, as determined from low-angle x-ray reflectivity and magnetoresistance values is only weakly affected by annealing at 250 C. We conclude from these results that the Cu/Co interfaces are not strongly affected, and we suspect that the thermally induced changes in these samples include partial oxidation which occurs mainly in the grain boundaries, which lie perpendicular to the film plane. RP McMichael, RD (reprint author), NIST,GAITHERSBURG,MD 20899, USA. RI Dura, Joseph/B-8452-2008; McMichael, Robert/J-8688-2012; OI Dura, Joseph/0000-0001-6877-959X; McMichael, Robert/0000-0002-1372-664X NR 10 TC 3 Z9 3 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD SEP PY 1996 VL 32 IS 5 BP 4636 EP 4638 DI 10.1109/20.539102 PN 2 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA VM259 UT WOS:A1996VM25900112 ER PT J AU Nikitenko, VI Gornakov, VS Dedukh, LM Kabanov, YP Khapikov, AF Bennett, LH Chen, PJ McMichael, RD Donahue, MJ Swartzendruber, LJ Shapiro, AJ Brown, HJ Egelhoff, WF AF Nikitenko, VI Gornakov, VS Dedukh, LM Kabanov, YP Khapikov, AF Bennett, LH Chen, PJ McMichael, RD Donahue, MJ Swartzendruber, LJ Shapiro, AJ Brown, HJ Egelhoff, WF TI Magneto-optical indicator film study of the magnetization of a symmetric spin valve SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 1996 IEEE International Magnetics Conference (INTERMAG 96) CY APR 09-12, 1996 CL SEATTLE, WA SP IEEE ID DOMAIN-STRUCTURE; MAGNETORESISTANCE; MULTILAYERS AB A magneto-optical indicator film (MOIF) technique is used for direct experimental study of the magnetization reversal process in a symmetric NiO/Co/Cu/NiFe/Cu/Co/NiO spin valve. It is shown for the first time that the reversal of the free center layer proceeds by nonuniform magnetization rotation. The observed switching mechanism is presumed to be associated with the influence of the nonuniform magnetostatic field that follows from surface roughness and the polycrystalline structure of the magnetic layers. C1 RUSSIAN ACAD SCI,INST SOLID STATE PHYS,CHERNOGOLOVKA 142432,MOSCOW DIST,RUSSIA. NIST,GAITHERSBURG,MD 20899. RI McMichael, Robert/J-8688-2012; OI McMichael, Robert/0000-0002-1372-664X NR 7 TC 6 Z9 6 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD SEP PY 1996 VL 32 IS 5 BP 4639 EP 4641 DI 10.1109/20.539103 PN 2 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA VM259 UT WOS:A1996VM25900113 ER PT J AU Kirschenbaum, LS Rogers, CT Beale, PD Russek, SE Sanders, SC AF Kirschenbaum, LS Rogers, CT Beale, PD Russek, SE Sanders, SC TI High current density self-field effects and low-frequency noise in NiFe/Ag GMR multilayers SO IEEE TRANSACTIONS ON MAGNETICS LA English DT Article; Proceedings Paper CT 1996 IEEE International Magnetics Conference (INTERMAG 96) CY APR 09-12, 1996 CL SEATTLE, WA SP IEEE ID GIANT MAGNETORESISTANCE AB High current densities (10(6)-10(7) A/cm(2)) produce magnetic fields which can induce antiparallel magnetic alignment in large (16 mu m and 8 mu m) NiFe/Ag thin film multilayer devices. We induce GMR in unannealed devices which normally do not display GMR. We find multiple peaks in the magnetoresistance curves of annealed and unannealed devices. Analysis of the positions and shapes of these magnetoresistance peaks provides a new set of tools for determining the micromagnetic structure of the multilayers. Our magneto-optical Kerr effect data and low frequency noise data correlate with the magnetoresistance peaks and may yield further information about layer-layer interactions and domain structure. C1 NATL INST STAND & TECHNOL,DIV ELECTROMAGNET TECHNOL,BOULDER,CO 80303. RP Kirschenbaum, LS (reprint author), UNIV COLORADO,CONDENSED MATTER LAB,BOULDER,CO 80309, USA. NR 6 TC 3 Z9 3 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9464 J9 IEEE T MAGN JI IEEE Trans. Magn. PD SEP PY 1996 VL 32 IS 5 BP 4684 EP 4686 DI 10.1109/20.539118 PN 2 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA VM259 UT WOS:A1996VM25900128 ER PT J AU Kaschnitz, E Cezairliyan, A AF Kaschnitz, E Cezairliyan, A TI Radiance temperatures at 1500 nm of niobium and molybdenum at their melting points by a pulse-heating technique SO INTERNATIONAL JOURNAL OF THERMOPHYSICS LA English DT Article; Proceedings Paper CT 4th Workshop on Subsecond Thermophysics CY JUN 27-29, 1996 CL DEUT FORSCHUNGSANSTALT LUFTFAHRT & RAUMFAHRT, COLOGNE, GERMANY HO DEUT FORSCHUNGSANSTALT LUFTFAHRT & RAUMFAHRT DE emissivity (normal spectral); high-speed pyrometry; high-temperature reference points; melting; molybdenum; niobium; radiance temperature AB Radiance temperatures at 1500 nm of niobium and molybdenum at their melting points were measured by a pulse-heating technique. The method is based on rapid resistive self-heating of the strip-shaped specimen from room temperature to its melting point in less than 1 s and measuring the specimen radiance temperature every 0.5 ms with a high-speed infrared pyrometer. Melting of the specimen was manifested by a plateau in the radiance temperature-versus-time function. The melting-point radiance temperature for a given specimen was determined by averaging the measured values along the plateau. A total of 12 to 13 experiments was performed for each metal under investigation. The melting-point radiance temperatures for each metal were determined by averaging the results of the individual specimens. The results for radiance temperatures at 1500 nm are as follows: 1983 K for niobium and 2050 K for molybdenum. Based on the estimates of the uncertainties arising from the use of pyrometry and specimen conditions, the combined uncertainty (two standard-deviation level) in the reported Values is +/-8 K. C1 NIST,DIV MET,GAITHERSBURG,MD 20899. NR 11 TC 15 Z9 15 U1 1 U2 2 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0195-928X J9 INT J THERMOPHYS JI Int. J. Thermophys. PD SEP PY 1996 VL 17 IS 5 BP 1069 EP 1078 DI 10.1007/BF01441995 PG 10 WC Thermodynamics; Chemistry, Physical; Mechanics; Physics, Applied SC Thermodynamics; Chemistry; Mechanics; Physics GA VG264 UT WOS:A1996VG26400009 ER PT J AU Baker, DJ AF Baker, DJ TI Coasts in crisis SO ISSUES IN SCIENCE AND TECHNOLOGY LA English DT Letter RP Baker, DJ (reprint author), NOAA,DEPT COMMERCE,WASHINGTON,DC 20230, USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 SN 0748-5492 J9 ISSUES SCI TECHNOL JI Issues Sci. Technol. PD FAL PY 1996 VL 13 IS 1 BP 17 EP 19 PG 3 WC Engineering, Multidisciplinary; Engineering, Industrial; Multidisciplinary Sciences; Social Issues SC Engineering; Science & Technology - Other Topics; Social Issues GA VM203 UT WOS:A1996VM20300020 ER PT J AU Stubbs, DA Dutton, RE AF Stubbs, DA Dutton, RE TI An ultrasonic sensor for high-temperature materials processing SO JOM-JOURNAL OF THE MINERALS METALS & MATERIALS SOCIETY LA English DT Article AB A sensor has been developed and tested thar is capable of emitting and receiving ultrasonic energy at temperatures exceeding 900 degrees C and pressures above 150 MPa. The sensor works with standard ultrasonic pulser-receivers and has demonstrated the capability of measuring workpiece deformation during hot isostatic pressing. Details of the sensor design, performance, and coupling of the ultrasound to the workpiece are described. Ultrasonic data acquired by the sensor in-situ during hot-isostatic-pressing runs are presented. C1 NATL INST STAND & TECHNOL,WRIGHT PATTERSON AFB,OH. RP Stubbs, DA (reprint author), UNIV DAYTON,RES INST,300 COLL PK DR,DAYTON,OH 45469, USA. NR 6 TC 27 Z9 27 U1 0 U2 1 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 1047-4838 J9 JOM-J MIN MET MAT S JI JOM-J. Miner. Met. Mater. Soc. PD SEP PY 1996 VL 48 IS 9 BP 29 EP 31 PG 3 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing SC Materials Science; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing GA VG137 UT WOS:A1996VG13700005 ER PT J AU Kent, RM Ruddell, MJ AF Kent, RM Ruddell, MJ TI The in-situ sensor-guided process characterization of advanced composite materials SO JOM-JOURNAL OF THE MINERALS METALS & MATERIALS SOCIETY LA English DT Article AB This article describes the multifunctional use of fibers as reinforcements and acoustic waveguides for sensing the fiber-matrix interfacial conditions during processing. It is shown that monitoring the ultrasonic signal response through a reinforcing fiber in a composite material yields on-line information that is related to the densification of the composite in the vicinity of the interface. Leakage of ultrasound from the fiber to the matrix is shown to be function of the density of the matrix at the interface. It is also shown that these data can then be used to feed back to the process for optimization and control. C1 UNIV DAYTON,RES CTR,STRUCT INTEGR DIV,DAYTON,OH 45469. RP Kent, RM (reprint author), NATL INST STAND & TECHNOL,MAT DIRECTORATE,WRIGHT PATTERSON AFB,OH 45433, USA. NR 11 TC 1 Z9 1 U1 0 U2 0 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 1047-4838 J9 JOM-J MIN MET MAT S JI JOM-J. Miner. Met. Mater. Soc. PD SEP PY 1996 VL 48 IS 9 BP 32 EP 34 PG 3 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing SC Materials Science; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing GA VG137 UT WOS:A1996VG13700006 ER PT J AU Chuang, TJ Chu, JL Lee, S AF Chuang, TJ Chu, JL Lee, S TI Diffusive crack growth at a bimaterial interface SO JOURNAL OF APPLIED MECHANICS-TRANSACTIONS OF THE ASME LA English DT Article; Proceedings Paper CT International Mechanical Engineering Congress and Exposition - Winter Annual Meeting of the ASME CY NOV 17-22, 1996 CL ATLANTA, GA SP ASME ID CREEP CAVITATION; TENSILE CREEP; FRACTURE; CERAMICS; TEMPERATURE; COMPOSITES AB The high temperature microcrack growth behavior along a planar interface between two elastic dissimilar media is investigated with an aim at estimating service life of advanced ceramic composites under creep-rupture conditions. The crack is assumed to grow along the interface normal to a remote applied tensile stress via a coupled surface and grain-boundary diffusion under steady-state creep conditions. The crack-tip conditions were first derived from the asymmetric tip morphology developed by surface self-diffusion. The governing integro-differential equation containing the unknown tensile stress distribution along the interface ahead of the moving crack tip was derived and it was found that a new length parameter exists as a scaling factor for the interface for which the solution becomes identical to that of the single-phrase media when plotted on the nondimensional physical plane. In contrast to the elastic stress solution which shows singularity at the tip and oscillatory character away from the tip, the creep stresses have a peak value away from the tip due to a wedging effect and interfacial sliding eliminates stress oscillation resulting in a decoupling between mode I and mode II stress fields. This stress solution ties for far-field loading parameter to the crack-tip conditions in terms of the unknown crack velocity to give a specific V-K functional relationship. It was shown that a stress exponent of 12 in the conventional power-law crack growth emerges at higher applied stress levels. An analysis on energy balance shows that the energy release during crack growth amounts to the J-integral which derives mostly from work done by ''wedging,'' not from strain energy loss. A constraint on interfacial diffusivities of the two species was found and its implications on possible microstructural developments were discussed. C1 NATL TSING HUA UNIV,DEPT MAT SCI & ENGN,HSINCHU 30043,TAIWAN. RP Chuang, TJ (reprint author), NIST,DIV CERAM,GAITHERSBURG,MD 20899, USA. NR 34 TC 14 Z9 14 U1 1 U2 1 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0021-8936 J9 J APPL MECH-T ASME JI J. Appl. Mech.-Trans. ASME PD SEP PY 1996 VL 63 IS 3 BP 796 EP 803 DI 10.1115/1.2823365 PG 8 WC Mechanics SC Mechanics GA VL348 UT WOS:A1996VL34800031 ER PT J AU Stith, J Scala, J Reinking, R Martner, B AF Stith, J Scala, J Reinking, R Martner, B TI Combined use of three techniques for studying transport and dispersion in cumuli SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article; Proceedings Paper CT 6th World-Meteorological-Organization Scientific Conference on Weather Modification CY MAY-JUN -, 1994 CL PAESTUM, ITALY SP World Meteorol Org ID TRACIR; CLOUDS AB The results from three methods for studying transport and dispersion in cumuli are compared. These three methods include two tracer techniques and a numerical simulation. The tracers, SF6 and radar chaff, were simultaneously released below the base of a convective storm. The SF6 was measured in situ by two research. aircraft and the chaff was followed using TRACIR (tracking air with circular-polarized radar), a method that measures the circular depolarization ratio (CDR) of the chaff, which is much stronger than that of most hydrometeors. TRACIR allows the CDR signal from the chaff to be measured and traced even when the reflectivity from the chaff is much less than that from the cloud. The behavior of the two-tracer release was compared with the trajectories of air from a two-dimensional simulation of the storm, using a nonhydrostatic cloud model, the National Aeronautics and Space Administration/Goddard Cumulus Ensemble Model. By combining information hom the three techniques, their individual shortcomings are alleviated, and a more complete documentation of transport and dispersion is provided. The tracers were followed during a 32-min period as they were transported 6 km vertically by the storm at an average rate of 2.6 m s(-1). This was within the ranges of the vertical transport rate of trajectories in the model simulation. The maximum updraft speed measured by the aircraft was 18 m s(-1), which agreed well with the maximum updraft in the simulations of 20 m s(-1). Both the simulation and the chaff observations show that portions of the released material were incorporated into the cloud and other portions were not. The main area of downward transport was located in the lower third of the simulated cloud where the rainfall was the heaviest. Major downdrafts were not found in the upper regions of the storm where the aircraft were sampling. The simulation suggests that the precipitation;induced downdraft played the major role in determining the trajectories of air from the cloud base, at least at the mature stage of the storm. Interactions between cloud-base air and downdrafts took place in the lower third of the storm where the bulk of the precipitation was located. C1 UNIV N DAKOTA,GRAND FORKS,ND 58201. NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. NOAA,ENVIRONM TECHNOL LAB,BOULDER,CO. NR 11 TC 3 Z9 3 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD SEP PY 1996 VL 35 IS 9 BP 1387 EP 1401 DI 10.1175/1520-0450(1996)035<1387:CUOTTF>2.0.CO;2 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VJ476 UT WOS:A1996VJ47600002 ER PT J AU Reinking, RF Martner, BE AF Reinking, RF Martner, BE TI Feeder-cell ingestion of seeding aerosol from cloud base determined by tracking radar chaff SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article; Proceedings Paper CT 6th World-Meteorological-Organization Scientific Conference on Weather Modification CY MAY-JUN -, 1994 CL PAESTUM, ITALY SP World Meteorol Org ID TRACIR AB Questions of delivery, transport, and dispersion of cloud seeding aerosol in a convective feeder cloud are addressed by using radar chaff as a surrogate for aerosol and tracking it with circular-polarization radar. In a case study, a line source of chaff was released by an aircraft at the roots of a growing cloud flanking and feeding into a thunderstorm line. The chaff was tracked as it dispersed in the boundary layer and rose more than 3 km from the cloud base at +14 degrees C to levels cold enough to nucleate ice-forming seeding aerosols. Quantitative measures of the rates of loft and dispersion, and the volume filling and dilution were obtained. The measurements permit examination of the hypotheses and potential efficacy of cloud-base seeding to increase rain and suppress hail. Notably, the problem of delivery, transport, and dispersion of cloud seeding aerosol is much the same as the air quality question of the nature and effect of cloud venting of the boundary layer, and the findings here apply in that context as well. RP Reinking, RF (reprint author), NOAA,ERL,ENVIRONM TECHNOL LAB,REET6,325 BROADWAY,BOULDER,CO 80303, USA. NR 13 TC 2 Z9 3 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD SEP PY 1996 VL 35 IS 9 BP 1402 EP 1415 DI 10.1175/1520-0450(1996)035<1402:FCIOSA>2.0.CO;2 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VJ476 UT WOS:A1996VJ47600003 ER PT J AU Dobrow, RP AF Dobrow, RP TI On the distribution of distances in recursive trees SO JOURNAL OF APPLIED PROBABILITY LA English DT Article DE recursive trees; stirling numbers of the first kind ID RECORDS AB Recursive trees have been used to model such things as the spread of epidemics, family trees of ancient manuscripts, and pyramid schemes. A tree T-n with n labeled nodes is a recursive tree if n=1, or n>1 and T-n can be constructed by joining node n to a node of some recursive tree T-n-1. For arbitrary nodes i 0.5) are found for certain stations in the northern Tropics at lead times of 3 months or less in late northern winter. especially in the western Pacific. CCA generally outperforms persistence, even at short leads. The El Nino-Southern Oscillation (ENSO) phenomenon is found to play the dominant role in the precipitation variability at many tropical Pacific islands. During especially the late northern winter of mature warm (cold) episodes, precipitation is suppressed (enhanced) in a horseshoe-shaped region surrounding (to the north, west, south) the central and eastern equatorial zone. which is anomalously wit (dry). A secondary source of predictive skill, most important for northern summer, is a pattern with like-signed SST anomalies over the Tropics of all three ocean basins. While this pattern may encompass ENSO episodes, it varies at lower frequencies than the ENSO phenomenon on its own. RP He, YX (reprint author), NOAA,CLIMATE PREDICT CTR,NATL CTR ENVIRONM PREDICT,NWS,W-NP51 WWB ROOM 604,WASHINGTON,DC 20233, USA. NR 20 TC 35 Z9 38 U1 0 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD SEP PY 1996 VL 9 IS 9 BP 2020 EP 2035 DI 10.1175/1520-0442(1996)009<2020:LLFOSP>2.0.CO;2 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VM997 UT WOS:A1996VM99700004 ER PT J AU Lau, NC Nath, MJ AF Lau, NC Nath, MJ TI The role of the ''atmospheric bridge'' in linking tropical Pacific ENSO events to extratropical SST anomalies SO JOURNAL OF CLIMATE LA English DT Article ID SEA-SURFACE TEMPERATURE; HEMISPHERE WINTERTIME CIRCULATION; STOCHASTIC CLIMATE MODELS; HEAT-FLUX ANOMALIES; NORTH PACIFIC; EL-NINO; INTERDECADAL VARIABILITY; SOUTHERN OSCILLATION; OCEAN INTERACTION; SIMULATION AB The role of the atmospheric circulation as a ''bridge'' between sea surface temperature (SST) anomalies in the tropical Pacific and those in the midlatitude northern oceans is assessed. The key processes associated with this atmospheric bridge are described using output from four independent simulations with a general circulation model subjected to month to month SST variations observed in the tropical Pacific during the 1946-1988 period and to climatological SST conditions elsewhere(the ''TOGA'' runs). In episodes with prominent SST anomalies in the tropical Pacific. extratropical perturbations in the simulated atmospheric temperature, humidity, and wind fields induce changes in the latent and sensible heat fluxes across the air-sea interface of the midlatitude oceans. These anomalous fluxes in turn lead to extratropical SST changes. The relevance of the atmospheric bridge mechanism is evaluated by driving a motionless, 50-m deep oceanic mixed layer model at individual grid points with the local surface fluxes generated in the TOGA runs. The negative feedback of the mixed layer temperature anomalies on the imposed flux forcing is taken into account by introducing a linear damping term with a 5-month dissipative time scale. This simple system reproduces the basic spatial and temporal characteristics of the observed SST variability in the North Pacific and western North Atlantic. The two-way air-sea feedbacks associated with the atmospheric bridge are investigated by performing four additional 43-year runs of a modified version of the TOGA Experiment. These new ''TOGA-ML'' runs predict the ocean temperature outside the tropical Pacific by allowing the atmosphere to interact Fully with the same mixed layer model mentioned above. The results support the notion that midlatitude ocean-atmosphere interaction can be modeled as a first-order Markov process, in which the red-noise response of mixed layer temperature is driven by white-noise atmospheric forcing in the presence of linear damping. The amplitude of near-surface atmospheric anomalies appearing in the TOGA-ML runs is higher than that in the TOGA runs. This finding implies that, in the TOGA-h PL scenario, the midlatitude oceanic responses to atmospheric driving could exert positive feedbacks on the atmosphere, thereby reinforcing the air-sea coupling. The enhanced atmosphere-ocean interactions operating in TOGA-h IL prolong the duration of persistent meteorological episodes in that experiment. A comprehensive survey is conducted of the persistence characteristics simulated in TOGA, TOGA-ML, and several other experiments subjected to prescribed SST forcing at various sites. Model scenarios in which observed tropical Pacific SST anomalies act in conjunction with SST perturbations in midlatitudes (either prescribed or predicted) are seen to produce the highest frequency of persistent events. RP Lau, NC (reprint author), PRINCETON UNIV,NOAA,GEOPHYS FLUID DYNAM LAB,POB 308,PRINCETON,NJ 08542, USA. NR 38 TC 281 Z9 297 U1 6 U2 30 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD SEP PY 1996 VL 9 IS 9 BP 2036 EP 2057 DI 10.1175/1520-0442(1996)009<2036:TROTBI>2.0.CO;2 PG 22 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VM997 UT WOS:A1996VM99700005 ER PT J AU Thacker, WC AF Thacker, WC TI Climatic fingerprints, patterns, and indices SO JOURNAL OF CLIMATE LA English DT Article AB The purpose of this note is to point out that Hasselmann's optimal fingerprints for detecting climatic change follow from the geometrical interpretation of covariance as an inner product. RP Thacker, WC (reprint author), USDC,NOAA,ATLANTIC OCEANOG & METEOROL LAB,4301 RICKENBACKER CAUSEWAY,MIAMI,FL 33149, USA. RI Thacker, Carlisle/I-3813-2013 OI Thacker, Carlisle/0000-0002-9285-8826 NR 5 TC 4 Z9 4 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD SEP PY 1996 VL 9 IS 9 BP 2259 EP 2261 DI 10.1175/1520-0442(1996)009<2259:CFPAI>2.0.CO;2 PG 3 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VM997 UT WOS:A1996VM99700021 ER PT J AU Niedrauer, T Paul, C Zaitzeff, J ClementeColon, P AF Niedrauer, T Paul, C Zaitzeff, J ClementeColon, P TI Multispectral video measurements over the Chesapeake Bay SO JOURNAL OF COASTAL RESEARCH LA English DT Article DE remote sensing; imaging; airborne sensors ID SPECTRAL CURVATURE ALGORITHMS; CHLOROPHYLL; PIGMENTS AB NOAA's Airborne Multispectral Measurement System (AMMS) is compared to NASA's Airborne Oceanographic Lidar (AOL) with its integral passive ocean color subsystem (POCS) by analyzing a data set collected in April 1991 over the Chesapeake Bay. In this remote sensing experiment, the AMMS and AOL were mounted on a NASA P3 aircraft that flew two passes over a study region at an altitude of 150 m, while a ship collected sea surface samples. The AMMS included a 6 channel multispectral video camera and upward and downward looking spectrometers. The AOL used a laser operating at 532 nm and a 32 channel passive radiometer. A ship gathered sea surface samples, which were analyzed for chlorophyll-a, pheophytin, and seston. The remote sensing measurements from the instruments were in good agreement when the effects of different sampling times and the different sampling areas are taken into consideration. C1 NOAA,NATL ENVIRONM SATELLITE DATA & INFORMAT SERV,OCEAN SCI BRANCH,WASHINGTON,DC 20233. RP Niedrauer, T (reprint author), XYBION CORP,240 CEDAR KNOLLS RD,CEDAR KNOLLS,NJ 07927, USA. RI Clemente-Colon, Pablo/F-5581-2010 NR 14 TC 0 Z9 0 U1 0 U2 1 PU COASTAL EDUCATION & RESEARCH FOUNDATION PI LAWRENCE PA 810 EAST 10TH STREET, LAWRENCE, KS 66044 SN 0749-0208 J9 J COASTAL RES JI J. Coast. Res. PD FAL PY 1996 VL 12 IS 4 BP 969 EP 976 PG 8 WC Environmental Sciences; Geography, Physical; Geosciences, Multidisciplinary SC Environmental Sciences & Ecology; Physical Geography; Geology GA VX661 UT WOS:A1996VX66100021 ER PT J AU Singh, NB Glicksman, ME Coriell, SR Duval, WMB Santoro, GJ DeWitt, R AF Singh, NB Glicksman, ME Coriell, SR Duval, WMB Santoro, GJ DeWitt, R TI Measurement of diffusion coefficient using a diaphragm cell: PbBr2-AgBr system SO JOURNAL OF CRYSTAL GROWTH LA English DT Article ID LEAD BROMIDE CRYSTALS; QUALITY; GROWTH AB The diffusion coefficient of molten lead bromide-silver bromide was determined using a two chamber diaphragm cell separated by the porous membrane of a sintered glass disk. Only dilute mixtures of PbBr2-AgBr were studied. The interdiffusion coefficient was determined to be 1.71 x 10(-5) cm(2)/s. C1 RENSSELAER POLYTECH INST,DEPT MAT SCI & ENGN,TROY,NY 12180. NIST,DIV MET,GAITHERSBURG,MD 20899. NASA,LEWIS RES CTR,CLEVELAND,OH 44135. RP Singh, NB (reprint author), NORTHROP GRUMMAN SCI & TECHNOL CTR,PITTSBURGH,PA 15235, USA. OI Glicksman, Martin/0000-0002-2675-2759 NR 4 TC 7 Z9 8 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0248 J9 J CRYST GROWTH JI J. Cryst. Growth PD SEP PY 1996 VL 167 IS 1-2 BP 107 EP 110 DI 10.1016/0022-0248(96)00245-X PG 4 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA VN615 UT WOS:A1996VN61500013 ER PT J AU Hastie, GP Johnstone, J Roberts, KJ Fischer, D AF Hastie, GP Johnstone, J Roberts, KJ Fischer, D TI Application of polarised ultra-soft X-ray absorption near-edge spectroscopy to the characterisation of the structure of molecular interfaces SO JOURNAL OF CRYSTAL GROWTH LA English DT Article; Proceedings Paper CT 11th International Conference on Crystal Growth CY JUN 18-23, 1995 CL THE HAGUE, NETHERLANDS SP Int Org Crystal Growth, Dutch Assoc Crystal Growth ID NORMAL-ALKANES; SOLID-STATE; SURFACE; TRANSITION; PHASE AB The use and suitability of synchrotron, polarised ultra-soft X-ray absorption near-edge structure (XANES) spectroscopy, for surface characterisation in realistic thermodynamic conditions is described and illustrated through an examination of the melting characteristics of the surface and subsurface regions of a normal alkane thin film deposited on Si(111). C1 HERIOT WATT UNIV,DEPT MECH & CHEM ENGN,CTR MOL & INTERFACE ENGN,EDINBURGH EH14 4AS,MIDLOTHIAN,SCOTLAND. UNIV STRATHCLYDE,DEPT PURE & APPL CHEM,GLASGOW G1 1XL,LANARK,SCOTLAND. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. SERC,DARESBURY LAB,WARRINGTON WA4 4AD,CHESHIRE,ENGLAND. NR 24 TC 6 Z9 6 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0248 J9 J CRYST GROWTH JI J. Cryst. Growth PD SEP PY 1996 VL 166 IS 1-4 BP 67 EP 71 DI 10.1016/0022-0248(96)00085-1 PG 5 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA VM089 UT WOS:A1996VM08900009 ER PT J AU Singh, NB Mani, SS Adam, JD Coriell, SR Glicksman, ME Duval, WMB Santoro, GJ DeWitt, R AF Singh, NB Mani, SS Adam, JD Coriell, SR Glicksman, ME Duval, WMB Santoro, GJ DeWitt, R TI Direct observations of interface instabilities SO JOURNAL OF CRYSTAL GROWTH LA English DT Article; Proceedings Paper CT 11th International Conference on Crystal Growth CY JUN 18-23, 1995 CL THE HAGUE, NETHERLANDS SP Int Org Crystal Growth, Dutch Assoc Crystal Growth ID LEAD BROMIDE CRYSTALS; BINARY ALLOY; SOLIDIFICATION; GROWTH AB Single crystals of lead bromide doped with silver bromide were grown by the vertical Bridgman method. Direct observations were made in order to understand the interfacial instabilities. Numerical studies were carried out to provide a framework for interpreting the observed convective and morphological instabilities. Observations on interfacial instabilities in lead bromide with 500 and 5000 ppm silver bromide impurities supported the numerical results predicted for 1-g conditions. X-ray rocking curves, X-ray contour scans, and etch-pit studies showed that increasing solutal convection deteriorated the crystal quality of the crystals. C1 NIST,GAITHERSBURG,MD 20899. RENSSELAER POLYTECH INST,DEPT MAT SCI & ENGN,TROY,NY 12180. NASA,LEWIS RES CTR,CLEVELAND,OH 44135. RP Singh, NB (reprint author), WESTINGHOUSE SCI & TECHNOL CTR,1310 BEULAH RD,PITTSBURGH,PA 15235, USA. OI Glicksman, Martin/0000-0002-2675-2759 NR 7 TC 13 Z9 13 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0248 J9 J CRYST GROWTH JI J. Cryst. Growth PD SEP PY 1996 VL 166 IS 1-4 BP 364 EP 369 DI 10.1016/0022-0248(95)00529-3 PG 6 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA VM089 UT WOS:A1996VM08900063 ER PT J AU Hotsenpiller, PAM Wilson, GA Roshko, A Rothman, JB Rohrer, GS AF Hotsenpiller, PAM Wilson, GA Roshko, A Rothman, JB Rohrer, GS TI Heteroepitaxial growth of TiO2 films by ion-beam sputter deposition SO JOURNAL OF CRYSTAL GROWTH LA English DT Article; Proceedings Paper CT 11th International Conference on Crystal Growth CY JUN 18-23, 1995 CL THE HAGUE, NETHERLANDS SP Int Org Crystal Growth, Dutch Assoc Crystal Growth ID IONIZED CLUSTER BEAM; CHEMICAL-VAPOR-DEPOSITION; THIN-FILMS; EPITAXIAL TIO2 AB Heteroepitaxial TiO2 films of the rutile and anatase phases have been grown using the ion-beam sputter deposition technique. The orientations of the highest-quality rutile films grown and their corresponding substrates are (100)/(0001)Al2O3, (101)/(<11(2)over bar 0>)Al2O3, (001)/(<10(1)over bar 0>)Al2O3, and (110)/(110)MgO. This is the first report of the heteroepitaxial growth of (001)/(<10(1)over bar 0>)Al2O3 and (110)/(110)MgO rutile films. Results indicate that the films are aligned both perpendicular and parallel to the plane of the film. Distinct surface morphologies are observed for each orientation. The (100) and (101) rutile orientations were also grown on (111)MgO and (<1(1)over bar 02>)Al2O3, respectively. The (100) anatase grew on both (100)MgO and MgAl2O4. The growth mechanisms of several rutile films on Al2O3 substrates were investigated, and the data suggest island or Volmer-Weber type growth. C1 NATL INST STAND & TECHNOL,BOULDER,CO 80303. UNIV PENN,RES STRUCT MATTER LAB,PHILADELPHIA,PA 19104. CARNEGIE MELLON UNIV,DEPT MAT SCI & ENGN,PITTSBURGH,PA 15213. RP Hotsenpiller, PAM (reprint author), DUPONT CO INC,EXPT STN,WILMINGTON,DE 19880, USA. RI Rohrer, Gregory/A-9420-2008 OI Rohrer, Gregory/0000-0002-9671-3034 NR 18 TC 40 Z9 43 U1 0 U2 10 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0248 J9 J CRYST GROWTH JI J. Cryst. Growth PD SEP PY 1996 VL 166 IS 1-4 BP 779 EP 785 DI 10.1016/0022-0248(95)00569-2 PG 7 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA VM089 UT WOS:A1996VM08900136 ER PT J AU Skrtic, D Hailer, AW Takagi, S Antonucci, JM Eanes, ED AF Skrtic, D Hailer, AW Takagi, S Antonucci, JM Eanes, ED TI Quantitative assessment of the efficacy of amorphous calcium phosphate/methacrylate composites in remineralizing caries-like lesions artificially produced in bovine enamel SO JOURNAL OF DENTAL RESEARCH LA English DT Article DE amorphous calcium phosphate; caries; enamel; methacrylate composites; remineralization ID FLUORIDE MOUTHRINSE; INVITRO; TRANSFORMATION; PROGRESSION; DENTIFRICE; PH AB Recent studies show that methacrylate-based composites with amorphous calcium phosphate (ACP) as a filler can release supersaturating levels of calcium and phosphate ions in proportions favorable for apatite formation. These findings suggest that such composites could be effectively used as coatings for remineralizing teeth damaged by tooth decay. To examine this hypothesis, we tested composites in vitro for their efficacy to remineralize artificially formed caries-like lesions in extracted bovine incisors. Single 120-mu m-thick sagittal tooth sections were placed in holders that exposed only the carious enamel surface. The exposed surfaces were coated with a 1-mm- to 1.5-mm-thick layer of the composite containing, by mass, 40% apatite, silica, or P2O74--stabilized ACP and 60% photoactivated resin comprised of Bis-GMA, TEGDMA, HEMA, and ZrM. The photocured composite-coated sections were immersed either in a remineralizing solution for 4 weeks at 37 degrees C (static model) or cyclically immersed in demineralizing (0.5 h) and remineralizing solutions (11.5 h) for 2 weeks (dynamic model). Quantitative digital image analysis of matched 102 mu m x 220 mu m areas from contact microradiographs taken of the sections before and after immersion showed that lesions coated with ACP-filled composites fractionally recovered 71% +/- 33% of their lost mineral compared with 14% +/- 13% for apatite controls in the static model and 38% +/- 16% compared with -6% +/- 24% in the dynamic model. The results suggest that sealants based on ACP-filled methacrylate composites have the potential to remineralize carious enamel lesions. C1 NIDR,BONE RES BRANCH,NIH,BETHESDA,MD 20892. NIST,AMER DENT ASSOC HLTH FDN,PAFFENBARGER RES CTR,GAITHERSBURG,MD 20899. NIST,DENT & MED MAT GRP,DIV POLYMERS,GAITHERSBURG,MD 20899. FU NIDCR NIH HHS [DEO5354] NR 23 TC 96 Z9 97 U1 0 U2 4 PU AMER ASSOC DENTAL RESEARCH PI ALEXANDRIA PA 1619 DUKE ST, ALEXANDRIA, VA 22314 SN 0022-0345 J9 J DENT RES JI J. Dent. Res. PD SEP PY 1996 VL 75 IS 9 BP 1679 EP 1686 PG 8 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA VX041 UT WOS:A1996VX04100010 PM 8952621 ER PT J AU Moon, KW BOettinger, WJ Williams, ME Josell, D Murray, BT Carter, WC Handwerker, CA AF Moon, KW BOettinger, WJ Williams, ME Josell, D Murray, BT Carter, WC Handwerker, CA TI Dynamic aspects of wetting balance tests SO JOURNAL OF ELECTRONIC PACKAGING LA English DT Article AB The relationships between the force measured during wetting balance tests and the observed changes of contact angle and meniscus shape are studied. Experiments using silicone oil at 25, 50, and 100 degrees C on glass plates as,cell as Pb-Sn eutectic solder on Au-coated glass plates are reported. Discrepancies between the measured force and height and those expected for a static meniscus are detailed. Equilibrium meniscus shapes are computed for wide plates using the elastica solution and for narrow plates using the public-domain software package, ''Surface Evolver'' For room temperature experiments with oil, the measured force discrepancy disappears when the meniscus rise is complete. Thus, the force discrepancy may be due to shear stress exerted on the sample by fluid rising up the sample. For static menisci with heated liquids, force and meniscus height discrepancies do not disappear when the meniscus rise is complete. These discrepancies can be explained by Marangoni flow due to temperature gradients in the fluid for the oil experiments but not for the solder experiments. RP Moon, KW (reprint author), NIST,APPL & COMPUTAT MATH DIV,DIV MET,GAITHERSBURG,MD 20899, USA. NR 29 TC 13 Z9 13 U1 3 U2 5 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 1043-7398 J9 J ELECTRON PACKAGING JI J. Electron. Packag. PD SEP PY 1996 VL 118 IS 3 BP 174 EP 183 DI 10.1115/1.2792149 PG 10 WC Engineering, Electrical & Electronic; Engineering, Mechanical SC Engineering GA VN187 UT WOS:A1996VN18700011 ER PT J AU Davis, A Link, TE Baugh, K Witham, R AF Davis, A Link, TE Baugh, K Witham, R TI Stabilization of lead in acidic mine filtercake by addition of alkaline tailings SO JOURNAL OF ENVIRONMENTAL QUALITY LA English DT Article ID ADSORPTION; BIOAVAILABILITY; MONTANA; BUTTE; WATER; SOILS; IRON AB The potential for disposal of acidic Pb-bearing process waste in an alkaline tailings pond was assessed to ascertain if Pb would become stabilized as opposed to diluted during mixing. This study demonstrated that codisposal of the filtercake residue, consisting of ferrihydroxide, lead sulfate and lead oxide phases (pH = 6.2, Pb = 43 000 mg/kg), with tailings containing abundant calcium and strontium carbonate (pH = 9.8, Pb = 2400 mg/kg) would result in Ph stabilization. The leachable Pb was greater (p < 0.05%) for a sand-filtercake mixture compared with the tailings-filtercake at analogous ratios, demonstrating reactivity between filter cake and tailings. Stabilization occurs because abundant remnant calcite in the tailings neutralizes the acidic filtercake, facilitating sorption of Pb to ferrihydroxide at the pH of the filtercake/tailings mix and a >98.5% decrease in Pb solubility. Sorption (Kd(Pb) = 28 600 at pH 7.7) and possible precipitation of Ce-Pb and Ln-Pb oxides limit Pb solubility. These data suggest that disposal of acidic filtercake in an alkaline tailings pond would reduce Ph solubility to levels below relevant environmental standards. C1 OREGON STATE UNIV,DEPT GEOL,CORVALLIS,OR 97331. NOAA,NATL GEOPHYS DATA CTR,BOULDER,CO 80303. MOLYCORP,MT PASS,CA 92366. RP Davis, A (reprint author), GEOMEGA,2995 BASELINE RD,SUITE 202,BOULDER,CO 80303, USA. RI Link, Timothy/G-5556-2012 NR 25 TC 2 Z9 2 U1 0 U2 0 PU AMER SOC AGRONOMY PI MADISON PA 677 S SEGOE RD, MADISON, WI 53711 SN 0047-2425 J9 J ENVIRON QUAL JI J. Environ. Qual. PD SEP-OCT PY 1996 VL 25 IS 5 BP 1077 EP 1082 PG 6 WC Environmental Sciences SC Environmental Sciences & Ecology GA VH793 UT WOS:A1996VH79300019 ER PT J AU Bird, SL Esterly, DM Perry, SG AF Bird, SL Esterly, DM Perry, SG TI Off-target deposition of pesticides from agricultural aerial spray applications SO JOURNAL OF ENVIRONMENTAL QUALITY LA English DT Article ID DRIFT; RESIDUES AB Drift of pesticides at the times of aerial spray application is a source of concern because of potential impacts on human health, contamination of crops and livestock, and endangerment of sensitive ecological resources, A substantial body of information from field trials aimed at evaluating off-target deposition of pesticides from aerial spray applications was analyzed, Forty-five trials previously reported in the open literature were extrapolated and normalized and quantitatively compared to trials performed during the summer of 1992 in Plainview, TX, by the Spray Drift Task Force (SDTF). In general, the results observed in the SDTF studies are consistent with those reported in the open literature. Both sets of data show median values of pesticide deposition dropping from similar to 5% of the nominal application rate at 30 m downwind to similar to 0.5% at 150 m during low-flight applications. Based on results from these trials and others reported in the literature, droplet size is consistently the primary application variable controlling off-target drift during low-flight applications, Application of a fine spray with a volume median diameter (VMD) <200 mu m in an oil-based carrier, typical of ultra-low volume (ULV) applications, ran yield np to a 10-fold increase in off-target drift, whereas use of solid stream nozzles producing a relatively coarse spray (VMD > 500 mu m) can reduce drift 10-fold relative to conventional application equipment producing a medium spray (YMD similar to 300 mu m), Off-target drift increases with increasing wind speeds, but the magnitude of the effect is less significant than effects of droplet size. The SDTF trials were performed under neutral to unstable atmospheric conditions and the effects of stability for this range of conditions were not distinguishable from the effects of wind speed. In previously reported studies under a wider range of conditions, stability effects are most significant 100 m downwind and beyond with an increase in deposition of more than 10-fold reported on occasion between unstable and very stable conditions, Currently, pesticide use labels restrict application during strongly stable atmospheric conditions and during high winds. In conjunction with these weather-related restrictions, clear specification of nozzles and operating conditions is the best approach for effective control of off-site drift and deposition from aerial applications. C1 EI DUPONT NEMOURS & CO,WILMINGTON,DE 19880. NATL OCEAN & ATMOSPHER ADM,AIR RESOURCES LAB,ATMOSPHER SCI MODELING DIV,RES TRIANGLE PK,NC. RP Bird, SL (reprint author), US EPA,ECOSYST RES DIV,NATL EXPOSURE RES LAB,960 COLL STN RD,ATHENS,GA 30605, USA. NR 27 TC 51 Z9 54 U1 2 U2 9 PU AMER SOC AGRONOMY PI MADISON PA 677 S SEGOE RD, MADISON, WI 53711 SN 0047-2425 J9 J ENVIRON QUAL JI J. Environ. Qual. PD SEP-OCT PY 1996 VL 25 IS 5 BP 1095 EP 1104 PG 10 WC Environmental Sciences SC Environmental Sciences & Ecology GA VH793 UT WOS:A1996VH79300022 ER PT J AU Odstrcil, D Dryer, M Smith, Z AF Odstrcil, D Dryer, M Smith, Z TI Propagation of an interplanetary shock along the heliospheric plasma sheet SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID PLANE; MHD AB Propagation of an interplanetary shock along the heliospheric plasma sheet (HPS) is simulated using a high-resolution numerical MHD model in the meridional plane. The ambient solar wind contains two opposite orientations of the interplanetary magnetic field above and below the equatorial plane. These regions are separated by a thin transition layer that represents the heliospheric current sheet contained within the HPS. A pulse is introduced at the inner boundary (0.1 AU) into this steady state to initiate the interplanetary shock. The HPS with its weaker intensity of the magnetic field, larger mass density, and slower how velocity modifies the global shock structure. A dimple is formed at the forward shock front, a reverse dimple is formed at the reverse shock, and the contact discontinuity is significantly distorted. Weak compression of the HPS occurs beyond the forward shock front due to the postshock increase of the azimuthal magnetic pressure. Although slight collimation of mass flow takes place toward the axis of the HPS, an antisunward protrusion (''pimple'') within the shock front's dimple did not form in our simulation. C1 NOAA,SPACE ENVIRONM CTR,BOULDER,CO 80303. UNIV COLORADO,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. RP Odstrcil, D (reprint author), ASTRON INST,ONDREJOV 25165,CZECH REPUBLIC. RI xue, yansheng/A-9712-2012 NR 17 TC 55 Z9 56 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES JI J. Geophys. Res-Space Phys. PD SEP 1 PY 1996 VL 101 IS A9 BP 19973 EP 19986 DI 10.1029/96JA00479 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA VF257 UT WOS:A1996VF25700030 ER PT J AU Petersen, B AF Petersen, B TI Management of federal sponsored libraries: Case studies and analysis - Missar,CD SO JOURNAL OF GOVERNMENT INFORMATION LA English DT Book Review RP Petersen, B (reprint author), NOAA,CENT LIB,SILVER SPRING,MD 20910, USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1352-0237 J9 J GOV INFORM JI J. Gov. Inf. PD SEP-DEC PY 1996 VL 23 IS 5-6 BP 736 EP 738 DI 10.1016/S1352-0237(97)89747-X PG 3 WC Information Science & Library Science SC Information Science & Library Science GA VZ327 UT WOS:A1996VZ32700015 ER PT J AU Xu, HHK Smith, DT Jahanmir, S AF Xu, HHK Smith, DT Jahanmir, S TI Influence of microstructure on indentation and machining of dental glass-ceramics SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID MATERIAL-REMOVAL; MECHANISMS; SYSTEMS; ALUMINA AB The influence of microstructure on the abrasive machining and indentation response for a series of dental glass-ceramics was characterized. The experimental materials prepared for this study contained crystalline mica platelets that ranged in diameter from about 1 to 15 mu m, while the volume fraction of mica remained essentially constant. Damage formation and material removal behavior were studied as a function of mica platelet size using Vickers indentation, Berkovich instrumented indentation, and abrasive machining. In the instrumented indentation experiments, the energy absorbed in indentation decreased with increasing platelet size when indentations of equal penetration depth are made in each material. To characterize the grinding response, the normal and tangential forces for each material were measured as a function of the depth of cut in surface grinding, The grinding forces and the specific grinding energy at fixed depths of cut decreased with increasing the mica platelet size following the same trend observed in the fixed displacement indentation tests. Since the same microfracture process was observed to occur in both indentation and grinding, the absorbed indentation energy is proposed as a quantity for predicting the machining response of these glass-ceramics. RP NIST, AMER DENT ASSOC HLTH FDN, PAFFENBARGER RES CTR, GAITHERSBURG, MD 20899 USA. RI Smith, Douglas/I-4403-2016 OI Smith, Douglas/0000-0002-9358-3449 NR 33 TC 36 Z9 36 U1 0 U2 5 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 32 AVENUE OF THE AMERICAS, NEW YORK, NY 10013-2473 USA SN 0884-2914 EI 2044-5326 J9 J MATER RES JI J. Mater. Res. PD SEP PY 1996 VL 11 IS 9 BP 2325 EP 2337 DI 10.1557/JMR.1996.0296 PG 13 WC Materials Science, Multidisciplinary SC Materials Science GA VG138 UT WOS:A1996VG13800029 ER PT J AU Szykman, S Cagan, J AF Szykman, S Cagan, J TI Synthesis of optimal nonorthogonal routes SO JOURNAL OF MECHANICAL DESIGN LA English DT Article AB This paper introduces a novel approach to three dimensional routing optimization. Examples of routing tasks for engineering applications include routing of pipes, wires and air ducts. Traditionally, routing algorithms perform Manhattan, or orthogonal, routing. Nonorthogonal routing can be less costly than Manhattan routing and for applications such as automotive or aerospace design, Manhattan routing is impractical due to spatial limitations. The research presented in this paper uses simulated annealing as the basis of a nonorthogonal routing optimization algorithm. Several examples comparing the two approaches are given. RP Szykman, S (reprint author), NIST,MFG SYST INTEGRAT DIV,GAITHERSBURG,MD 20899, USA. NR 19 TC 9 Z9 9 U1 0 U2 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 1050-0472 J9 J MECH DESIGN JI J. Mech. Des. PD SEP PY 1996 VL 118 IS 3 BP 419 EP 424 DI 10.1115/1.2826902 PG 6 WC Engineering, Mechanical SC Engineering GA VK414 UT WOS:A1996VK41400016 ER PT J AU Kleiner, I Hougen, JT Grabow, JU Belov, SP Tretyakov, MY Cosleou, J AF Kleiner, I Hougen, JT Grabow, JU Belov, SP Tretyakov, MY Cosleou, J TI The third and fourth torsional states of acetaldehyde SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID INTERNAL-ROTATION; SPECTRUM; MILLIMETER; MOLECULE AB At least-squares fit is presented of 1105 far-infrared and 2860 microwave transitions in acetaldehyde, which sample rotational levels in all torsional states below the lowest-frequency small-amplitude vibration v(10). Four-fifths of these transitions, involving torsional states below the barrier (upsilon(t) less than or equal to 2), were treated in an earlier publication; here the theoretical model is further tested by extending the data set to include the upsilon(t) = 3 and 4 states above the barrier. The new data set includes (i) 224 upsilon(t) = 3 <-- 2 far-infrared transitions, (ii) Nizhny Novgorod RAD-2 a-typed and b-type submillimeter transitions in upsilon(t) = 2, which make more precise Delta K = +/-1 intervals in this last torsional state below the barrier, (iii) RAD-3 a-type submillimeter transitions in upsilon(t) = 3 and 4, and (iv) microwave and submillimeter measurements or remeasurements from NIST and Lille of transitions with upsilon(t) less than or equal to 4. The global fit, which uses an improved version of the computer program previously applied to the upsilon(t) less than or equal to 2 data, gave a weighted overall standard deviation of 1.21 with 55 adjusted and 2 fixed parameters. Residuals from the fit were close to experimental uncertainties for the infrared wavenumber measurements and for microwave and submillimeter frequency measurements below the barrier, but some residuals reached several MHz or more for frequency measurements involving levels near upsilon(10). We have attempted to achieve a qualitative understanding of the numerical results by presenting a general overview of internal rotation energy levels above the barrier and a theoretical discussion of torsion-rotation interactions among these levels. (C) 1996 Academic Press, Inc. C1 NIST,DIV MOL PHYS,GAITHERSBURG,MD 20899. INST PHYS APPL,MICROWAVE SPECT DIV,NIZHNII NOVGOROD 603024,RUSSIA. UNIV SCI & TECH LILLE FLANDRES ARTOIS,SPECT HERTZIENNE LAB,F-59655 VILLENEUVE DASCQ,FRANCE. UNIV PARIS 11,LAB PHYS MOL & APPLICAT,CNRS,UNITE PROPRE,F-75252 PARIS 05,FRANCE. RP Kleiner, I (reprint author), UNIV PARIS 06,LAB PHYS MOL & APPLICAT,CNRS,UNITE PROPRE,TOUR 13,4 PL JUSSIEU,BTE 76,F-75252 PARIS 05,FRANCE. NR 25 TC 63 Z9 63 U1 0 U2 3 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD SEP PY 1996 VL 179 IS 1 BP 41 EP 60 DI 10.1006/jmsp.1996.0182 PG 20 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA VC595 UT WOS:A1996VC59500005 ER PT J AU Omron, RM Walker, ARH Hilpert, G Fraser, GT Suenram, RD AF Omron, RM Walker, ARH Hilpert, G Fraser, GT Suenram, RD TI Rotational spectra of CH3CCH-NH3, NCCCH-NH3, and NCCCH-OH2 SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article ID TRANSFORM MICROWAVE SPECTROSCOPY; INTERNAL-ROTATION; COMPLEXES; SPECTROMETER; MOLECULES; METHANE; DIMER; BEAM AB Microwave spectra of NCCCH-NH3, CH3CCH-NH3, and NCCCH-OH2 have been recorded using a pulsed-nozzle Fourier-transform microwave spectrometer. The complexes NCCCH-NH3 and CH3CCH-NH3 are found to have symmetric-top structures with the acetylenic proton hydrogen bonded to the nitrogen of the NH3. The data for CH3CCH-NH3 are further consistent with free or nearly free internal rotation of the methyl top against the ammonia top. For NCCCH-OH2, the acetylenic proton is hydrogen bonded to the oxygen of the water. The complex has a dynamical C-2v structure, as evidenced by the presence of two nuclear-spin modifications of the complex. The hydrogen bond lengths and hydrogen-bond stretching force constants are 2.212 Angstrom and 10.8 N/m, 2.322 Angstrom and 6.0 N/m, and 2.125 Angstrom and 9.6 N/m for NCCCH-NH3, CH3CCH-NH3, and NCCCH-OH2, respectively. For the cyanoacetylene complexes, these bond lengths and force constants lie between the values for the related hydrogen cyanide and acetylene complexes of NH3 and H2O. The NH3 bending and weak-bond stretching force constants for CH3CCH-NH3 are less than those found in NCCCH-NH3, NCH-NH3, and HCCH-NH3, suggesting that the hydrogen bonding interaction is particularly weak in CH3CCH-NH3. The weakness of this hydrogen bond is partially a consequence of the orientation of the monomer electric dipole moments in the complex. In CH3CCH-NH3 the antialigned monomer dipole moments lead to a repulsive dipole-dipole interaction energy, while in NCH-NH3 and NCCCH-NH3 the aligned dipoles give an attraction interaction. (C) 1996 Academic Press, Inc. RP Omron, RM (reprint author), NIST,OPT TECHNOL DIV,GAITHERSBURG,MD 20899, USA. RI Hight Walker, Angela/C-3373-2009 OI Hight Walker, Angela/0000-0003-1385-0672 NR 31 TC 11 Z9 11 U1 0 U2 3 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD SEP PY 1996 VL 179 IS 1 BP 85 EP 93 DI 10.1006/jmsp.1996.0187 PG 9 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA VC595 UT WOS:A1996VC59500010 ER PT J AU Chase, MW AF Chase, MW TI NIST-JANAF thermochemical tables for the iodine oxides SO JOURNAL OF PHYSICAL AND CHEMICAL REFERENCE DATA LA English DT Review DE evaluated recommended data; iodine oxides; literature survey; spectroscopic properties; thermodynamic properties ID MOLECULE-COLLISION PROCESSES; ELECTRON RESONANCE SPECTRA; KINETIC DATA EVALUATION; IO RADICALS; ATMOSPHERIC CHEMISTRY; PHOTOCHEMICAL DATA; CRYSTAL-STRUCTURE; OZONE DEPLETION; NITRATE MELTS; GAS-PHASE AB The thermodynamic and spectroscopic properties of the iodine oxide species have been reviewed. Recommended NIST-JANAF Thermochemical Tables are given for six gaseous iodine oxides: IO, OIO, IOO, IOI, IIO, and IO3. Sufficient information is not available to generate thermochemical tables for any condensed phase species. Annotated bibliographies (over 400 references) are provided for all neutral iodine oxides which have been reported in the literature. There is a lack of experimental thermodynamic and spectroscopic information for all iodine oxide species, except IO(g) and OIO(g). The recommended thermochemical tables are based on estimates for the Structure, vibrational frequencies, and enthalpy of formation based in part on the spectroscopic and thermodynamic data for the other halogen oxides [J. Phys. Chem. Ref. Data 25, 551 (1996); 25, 1061 (1996)]. Although there is a definite lack of information in comparison with the other halides, this information is provided for the iodine oxides for the following reasons: (1) to complete the study of the halogen oxide family and (2) to stress the need for additional experimental measurements. Of all the species mentioned in the literature, many have not been isolated or characterized. In fact, some do not exist. Throughout this paper, uncertainties attached to recommended values correspond to the uncertainty interval, equal to twice the standard deviation of the mean. (C) 1996 American Institute of Physics and American Chemical Society. RP Chase, MW (reprint author), NATL INST STAND & TECHNOL, STAND REFERENCE DATA PROGRAM, GAITHERSBURG, MD 20879 USA. NR 399 TC 43 Z9 44 U1 0 U2 20 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0047-2689 J9 J PHYS CHEM REF DATA JI J. Phys. Chem. Ref. Data PD SEP-OCT PY 1996 VL 25 IS 5 BP 1297 EP 1340 PG 44 WC Chemistry, Multidisciplinary; Chemistry, Physical; Physics, Multidisciplinary SC Chemistry; Physics GA VP974 UT WOS:A1996VP97400001 ER PT J AU Christophorou, LG Olthoff, JK Rao, MVVS AF Christophorou, LG Olthoff, JK Rao, MVVS TI Electron interactions with CF4 SO JOURNAL OF PHYSICAL AND CHEMICAL REFERENCE DATA LA English DT Review DE carbon tetrafluoride; CF4; cross sections; electron interactions; scattering; ionization; attachment; dissociation; fragments; transport ID IONIZATION CROSS-SECTIONS; DIFFUSE-DISCHARGE SWITCHES; ENERGY-LOSS SPECTROSCOPY; FAST GAS-MIXTURES; IMPACT-IONIZATION; VIBRATIONAL-EXCITATION; CARBON TETRAFLUORIDE; ATTACHMENT COEFFICIENTS; TETRAFLUOROMETHANE CF4; SYNCHROTRON RADIATION AB Carbon tetrafluoride (CF4) is one of the most widely used components of feed gas mixtures employed for a variety of plasma-assisted material-processing applications. It has no stable excited states and, in a plasma environment, is an ideal source of reactive species, especially F atoms. To assess the behavior of CF4 in its use in manufacturing semiconductor devices and other applications, it is necessary to have accurate information about its fundamental properties and reactions, particularly its electronic and ionic interactions and its electron collision processes at low energies (< 100 eV). In this article we assess and synthesize the available information on the cross sections and/or the rate coefficients for collisional interactions of CF4 with electrons. Assessed information is presented on: (i) cross sections for electron scattering (total, momentum, elastic differential, elastic integral, inelastic), electron-impact ionization (total, partial, multiple, dissociative), electron-impact dissociation (total, and for dissociative excitation), and electron attachment (total, and for specific anions); (ii) coefficients for electron transport (electron drift velocity, transverse and longitudinal electron diffusion coefficients), electron attachment, and electron-impact ionization; and (iii) cross section sets derived from analyses of electron transport data. The limited ionization data on CF4 radicals are also presented, and references are made to measurements of electron transport properties of CF4 gas mixtures. Based upon the assessment of published experimental data, recommended values for various cross sections and coefficients are generated which are presented in graphical and tabular form. (C) 1996 American Institute of Physics and American Chemical Society. C1 UNIV TENNESSEE, DEPT PHYS, KNOXVILLE, TN 37996 USA. RP Christophorou, LG (reprint author), NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. NR 164 TC 233 Z9 234 U1 3 U2 30 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0047-2689 J9 J PHYS CHEM REF DATA JI J. Phys. Chem. Ref. Data PD SEP-OCT PY 1996 VL 25 IS 5 BP 1341 EP 1388 PG 48 WC Chemistry, Multidisciplinary; Chemistry, Physical; Physics, Multidisciplinary SC Chemistry; Physics GA VP974 UT WOS:A1996VP97400002 ER PT J AU Bush, ABG McWilliams, JC Peltier, WR AF Bush, ABG McWilliams, JC Peltier, WR TI The formation of oceanic eddies in symmetric and asymmetric jets .2. Late time evolution and coherent vortex formation SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID CYCLONIC RING EXPERIMENT; QUASI-GEOSTROPHIC MODEL; GULF-STREAM RING; PHYSICAL OCEANOGRAPHY; TROPOPAUSE FOLDS; MESOSCALE EDDIES; CIRCULATION; DYNAMICS; WARM; TRANSPORT AB The dynamical processes involved in eddy genesis, evolution, and demise as revealed in a series of high-resolution numerical simulations of perturbed oceanic jets are investigated. Comparisons are provided between the simulated eddy life cycles and observations of Gulf Stream warm- and cold-core rings. The dynamics of the meandering process, in particular, are analyzed in terms of the quasigeostrophic (QG) geopotential tendency equation. The vertical motions that develop during eddy genesis are analyzed in terms of the contribution to the QG omega equation by the advection of temperature and differential vertical vorticity. An examination of the cross-stream flux of isentropic potential vorticity during warm core and cold core events emphasizes the role of the near-field circulations, associated with the baroclinic meanderings of the jet, in the detachment and evolution of the simulated eddies, Comments are offered concerning the total heat transport by a ring alone as opposed to that effected by the dipolar structure formed by the ring and its near-field circulation. The spinup of deep circulations by the eddies is also examined and a comparison provided between the flow structure that develops in the oceanic frontal zone during ring formation and the flow that obtains during an atmospheric tropopause fold event. C1 UNIV TORONTO,DEPT PHYS,TORONTO,ON M5S 1A7,CANADA. PRINCETON UNIV,PROGRAM ATMOSPHER & OCEAN SCI,PRINCETON,NJ 08544. UNIV CALIF LOS ANGELES,DEPT ATMOSPHER SCI,LOS ANGELES,CA 90024. RI Peltier, William/A-1102-2008 NR 53 TC 12 Z9 12 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0022-3670 J9 J PHYS OCEANOGR JI J. Phys. Oceanogr. PD SEP PY 1996 VL 26 IS 9 BP 1825 EP 1848 DI 10.1175/1520-0485(1996)026<1825:TFOOEI>2.0.CO;2 PG 24 WC Oceanography SC Oceanography GA VM284 UT WOS:A1996VM28400009 ER PT J AU Ffield, A Gordon, AL AF Ffield, A Gordon, AL TI Tidal mixing signatures in the Indonesian seas SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID SURFACE-TEMPERATURE; INTERNAL TIDES; ENERGY; BISCAY; BAY; DISSIPATION; THERMOCLINE; CONVECTION; PACIFIC; BASINS AB Expressions of low-frequency tidal periods are found throughout the Indonesian Seas' temperature field, supporting the hypothesis that vertical mixing is enhanced within the Indonesian Seas by the tides. The thermal signatures of tidal mixing vary mostly at the fortnightly and monthly tidal periods due to nonlinear dynamics redistributing tidal energy into these periods. Away from the coasts, the largest tidal mixing signatures are observed in sea surface temperature within the Seram and Banda Seas. Most of the Indonesian Throughflow passes through the Banda Sea where strong vertical mixing modifies the thermocline by transferring surface heat and freshwater to deeper layers before the upper water column is exported to the Indian Ocean. Modulation of vertical eddy fluxes within the Indonesian Seas by fortnightly and monthly tides may act to regulate ocean-atmosphere fluxes. C1 COLUMBIA UNIV, DEPT GEOL SCI, PALISADES, NY 10964 USA. NOAA, ATLANTIC OCEANOG & METEOROL LAB, MIAMI, FL 33149 USA. RP Ffield, A (reprint author), COLUMBIA UNIV, LAMONT DOHERTY EARTH OBSERV, PALISADES, NY 10964 USA. RI Gordon, Arnold/H-1049-2011 OI Gordon, Arnold/0000-0001-6480-6095 NR 34 TC 73 Z9 76 U1 0 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-3670 J9 J PHYS OCEANOGR JI J. Phys. Oceanogr. PD SEP PY 1996 VL 26 IS 9 BP 1924 EP 1937 DI 10.1175/1520-0485(1996)026<1924:TMSITI>2.0.CO;2 PG 14 WC Oceanography SC Oceanography GA VM284 UT WOS:A1996VM28400015 ER PT J AU Woerdeman, DL Flynn, KM Dunkers, JP Parnas, RS AF Woerdeman, DL Flynn, KM Dunkers, JP Parnas, RS TI The use of evanescent wave fluorescence spectroscopy for control of the liquid molding process (Reprinted) SO JOURNAL OF REINFORCED PLASTICS AND COMPOSITES LA English DT Article ID CROSS-VALIDATION; CURED EPOXY; SENSOR AB Fluorescence has been demonstrated to be an accurate measurement of resin cure and is measured using an evanescent wave fiber-optic sensor. An economical optical fiber sensor has been developed with a refractive index in excess of 1.6, permitting evanescent wave monitoring of epoxy resins. In this work, the fluorescence wavelength-shift, which has been correlated with monomer conversion, is monitored during the liquid molding process. A hierarchical control strategy is being developed for liquid molding processes that will use the cure measurement provided by the evanescent wave fluorescence sensor. Single input/single output control loops are implemented at the base level to regulate the mold temperature, the vacuum pressure in the mold, either the inlet flow or pressure during injection, and the final mold pressure. A model-based feedback controller is implemented to control the chemical cure and manipulates the setpoint of the temperature controller to achieve cure control. A general high-level controller is under development to optimize the process under a wide range of operating conditions. C1 NATL INST STAND & TECHNOL,DIV POLYMERS,GAITHERSBURG,MD 20899. JOHNS HOPKINS UNIV,DEPT MAT SCI & ENGN,BALTIMORE,MD 21218. NR 36 TC 12 Z9 12 U1 0 U2 4 PU TECHNOMIC PUBL CO INC PI LANCASTER PA 851 NEW HOLLAND AVE, BOX 3535, LANCASTER, PA 17604 SN 0731-6844 J9 J REINF PLAST COMP JI J. Reinf. Plast. Compos. PD SEP PY 1996 VL 15 IS 9 BP 922 EP 943 PG 22 WC Materials Science, Composites; Polymer Science SC Materials Science; Polymer Science GA VE139 UT WOS:A1996VE13900004 ER PT J AU Proctor, JE Barnes, PY AF Proctor, JE Barnes, PY TI NIST high accuracy reference reflectometer-spectrophotometer SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE bidirectional; diffuse; hemispherical; monochromator; reflectance; reflectometer; scatter; spectrophotometer; specular AB A new reflectometer-spectrophotometer has been designed and constructed using state-of-the-art technology to enhance optical properties of materials measurements over the ultraviolet, visible, and near-infrared (UV-Vis-NIR) wavelength range (200 nn to 2500 nm). The instrument, Spectral Tri-function Automated Reference Reflectometer (STARR), is capable of measuring specular and diffuse reflectance, bidirectional reflectance distribution function (BRDF) of diffuse samples, and both diffuse and non-diffuse transmittance. Samples up to 30 cm by 30 cm can be measured. The instrument and its characterization are described. RP Proctor, JE (reprint author), NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. NR 6 TC 54 Z9 54 U1 1 U2 2 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD SEP-OCT PY 1996 VL 101 IS 5 BP 619 EP 627 DI 10.6028/jres.101.061 PG 9 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA VY341 UT WOS:A1996VY34100001 PM 27805081 ER PT J AU Fowler, JB AF Fowler, JB TI An oil-bath-based 293 K to 473 K blackbody source SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE aperture; blackbody; cavity; conical; emissivity; radiation; radiometry; reflectance; source; temperature; thermometer; oil bath AB A high temperature oil-bath-based-blackbody source has been designed and constructed in the Radiometric Physics Division at the National Institute of Standards and Technology, Gaithersburg, MD. The goal of this work was to design a large aperture blackbody source with highly uniform radiance across the aperture, good temporal stability, and good reproducibility. This blackbody source operates in the 293 K to 473 K range with blackbody temperature combined standard uncertainties of 7.2 mK to 30.9 mK. The calculated emissivity of this source is 0.9997 with a standard uncertainty of 0.0003. With a 50 mm limiting aperture at the cavity entrance, the emissivity increases to 0.99996. RP Fowler, JB (reprint author), NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. NR 6 TC 7 Z9 8 U1 0 U2 0 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD SEP-OCT PY 1996 VL 101 IS 5 BP 629 EP 637 DI 10.6028/jres.101.062 PG 9 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA VY341 UT WOS:A1996VY34100002 PM 27805082 ER PT J AU FitzPatrick, GJ Kelley, EF AF FitzPatrick, GJ Kelley, EF TI Comparative high voltage impulse measurement SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE high-voltage impulse; high-voltage reference measurement systems; impulse measurements; standard lightning impulse; transient measurements AB A facility has been developed for the determination of the ratio of pulse high voltage dividers over the range from 10 kV to 300 kV using comparative techniques with Kerr electro-optic voltage measurement systems and reference resistive voltage dividers. Pulse voltage ratios of test dividers can be determined with relative expanded uncertainties of 0.4 % (coverage factor k = 2 and thus a two standard deviation estimate) or less using the complementary resistive divider/Kerr cell reference systems. This paper describes the facility and specialized procedures used at NIST for the determination of test voltage divider ratios through comparative techniques. The error sources and special considerations in the construction and use of reference voltage dividers to minimize errors are discussed, and estimates of the measurement uncertainties are presented. RP FitzPatrick, GJ (reprint author), NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. NR 24 TC 4 Z9 4 U1 1 U2 2 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD SEP-OCT PY 1996 VL 101 IS 5 BP 639 EP 658 DI 10.6028/jres.101.063 PG 20 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA VY341 UT WOS:A1996VY34100003 PM 27805083 ER PT J AU Fick, SE Breckenridge, FR AF Fick, SE Breckenridge, FR TI Ultrasonic power output measurement by pulsed radiation pressure SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE medical ultrasonics; ultrasonic radiation pressure; ultrasonic transducer calibration; ultrasound power measurements ID SOUND AB Direct measurements of time-averaged spatially integrated output power radiated into reflectionless water loads can be made with high accuracy using techniques which exploit the radiation pressure exerted by sound on all objects in its path. With an absorptive target arranged to intercept the entirety of an ultrasound beam, total beam power can be determined as accurately as the radiation force induced on the target can be measured in isolation from confounding forces due to buoyancy, streaming, surface tension, and vibration. Pulse modulation of the incident ultrasound at a frequency well above those characteristics of confounding phenomena provides the desired isolation and other significant advantages in the operation of the radiation force balance (RFB) constructed in 1974. Equipped with purpose-built transducers and electronics, the RFB is adjusted to equate the radiation force and a counterforce generated by an actuator calibrated against reference masses using direct current as the transfer variable. Improvements made during its one overhaul in 1988 have nearly halved its overall measurement uncertainty and extended the capabilities of the RFB to include measuring the output of ultrasonic systems with arbitrary pulse waveforms. RP Fick, SE (reprint author), NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. NR 27 TC 17 Z9 17 U1 0 U2 1 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD SEP-OCT PY 1996 VL 101 IS 5 BP 659 EP 669 DI 10.6028/jres.101.064 PG 11 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA VY341 UT WOS:A1996VY34100004 PM 27805084 ER PT J AU Stone, J Phillips, SD Mandolfo, GA AF Stone, J Phillips, SD Mandolfo, GA TI Corrections for wavelength variations in precision interferometric displacement measurements SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE deadpath; interferometry AB Precision interferometric displacement measurements require deadpath corrections to account for variations in wavelength during the course of the measurement This paper discusses common errors in applying deadpath corrections and describes the correction necessary to fully account for variations in wavelength. C1 HEWLETT PACKARD CORP, SANTA CLARA, CA 95052 USA. RP Stone, J (reprint author), NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. NR 1 TC 15 Z9 16 U1 1 U2 3 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD SEP-OCT PY 1996 VL 101 IS 5 BP 671 EP 674 DI 10.6028/jres.101.065 PG 4 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA VY341 UT WOS:A1996VY34100005 PM 27805085 ER PT J AU Cook, LP WongNg, W Paranthaman, P AF Cook, LP WongNg, W Paranthaman, P TI Melting and vaporization of the 1223 phase in the system (Tl-Pb-Ba-Sr-Ca-Cu-O) SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE melting point; phase equilibria; thallia vapor pressure; Tl-Pb-Ba-Sr-Ca-Cu-O system; 1223 superconductor ID BULK SUPERCONDUCTIVITY; PINNING CENTERS; THIN-FILMS; (TL0.5PB0.5)SR2CA2CU3O9; 120-K; TAPE AB The melting and vaporization of the 1223 [(Tl,Pb):(Ba,Sr):Ca:Cu] oxide phase in the system (Tl-Pb-Ba-Sr-Ca-Cu-O) have been investigated using a combination of dynamic methods (differential thermal analysis, thermogravimetry, effusion) and post-quenching characterization techniques (powder x-ray diffraction, scanning electron microscopy, energy dispersive x-ray spectrometry). Vaporization rates, thermal events, and melt compositions were followed as a function of thallia loss from a 1223 stoichiometry. Melting and vaporization equilibria of the 1223 phase are complex, with as many as seven phases participating simultaneously. At a total pressure of 0.1 MPa the 1223 phase was found to melt completely at (980 +/- 5) degrees C in oxygen, at a thallia partial pressure (p(Tl2o)) of (4.6 +/- 0.5) kPa, where the quoted uncertainties are standard uncertainties, i.e., 1 estimated standard deviation. The melting reaction involves five other solids and a liquid, nominally as follows: 1223 --> 1212 + (Ca,Sr)(2)CuO3 + (Sr,Ca)CuO2 + BaPbO3 +(Ca,Sr) O + Liquid Stoichiometries of the participating phases have been determined from microchemical analysis, and substantial elemental substitution on the 1212 and 1223 crystallographic sites is indicated. The 1223 phase occurs in equilibrium with liquids from its melting point down to at least 935 degrees C. The composition of the lowest melting liquid detected for the bulk compositions of this study has been measured using microchemical analysis. Applications to the processing of superconducting wires and tapes are discussed. C1 OAK RIDGE NATL LAB, OAK RIDGE, TN 37831 USA. RP Cook, LP (reprint author), NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. NR 41 TC 2 Z9 2 U1 0 U2 3 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD SEP-OCT PY 1996 VL 101 IS 5 BP 675 EP 689 DI 10.6028/jres.101.066 PG 15 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA VY341 UT WOS:A1996VY34100006 PM 27805086 ER PT J AU Kaufman, V Whaling, W AF Kaufman, V Whaling, W TI Improved wavelengths and energy levels of doubly-ionized argon (Ar III) SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE argon; energy levels; parametric fit; spectrum; wavelengths; wavenumbers ID SPECTRUM AB New measurements of Ar III wavelengths between 508 Angstrom and 4183 Angstrom are combined with measurements from the literature to find improved values for the energy of most of the known levels in Ar III. Parameters derived from fitting the new level energies to an LS-coupling model are presented along with eigenvector compositions of the levels. On the basis of this analysis new designations are recommended for several levels. C1 CALTECH, PASADENA, CA 91125 USA. RP Kaufman, V (reprint author), NATL INST STAND & TECHNOL, GAITHERSBURG, MD 20899 USA. NR 21 TC 9 Z9 9 U1 0 U2 1 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD SEP-OCT PY 1996 VL 101 IS 5 BP 691 EP 704 DI 10.6028/jres.101.067 PG 14 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA VY341 UT WOS:A1996VY34100007 PM 27805087 ER PT J AU Martys, NS AF Martys, NS TI NIST tutorial/workshop on lattice gas and Boltzmann methods - Gaithersburg, MD August 21-23, 1995 SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Editorial Material RP Martys, NS (reprint author), NATL INST STAND & TECHNOL, BLDG & FIRE RES LAB, BLDG MAT DIV, GAITHERSBURG, MD 20899 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD SEP-OCT PY 1996 VL 101 IS 5 BP 705 EP 706 DI 10.6028/jres.101.068 PG 2 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA VY341 UT WOS:A1996VY34100008 PM 27805088 ER PT J AU Schultz, MK Burnett, WC Inn, KGW Thomas, JWL Lin, ZC AF Schultz, MK Burnett, WC Inn, KGW Thomas, JWL Lin, ZC TI NIST Speciation Workshop - Gaithersburg, MD June 13-15, 1995 SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Editorial Material ID SEQUENTIAL EXTRACTION PROCEDURE; TRACE-METALS; SEDIMENTS; ARTIFACTS; PARTICLES; FRACTIONS; SR-90; SOILS C1 NATL INST STAND & TECHNOL, PHYS LAB, IONIZING RADIAT DIV, RADIOACT GRP, GAITHERSBURG, MD 20899 USA. RP Schultz, MK (reprint author), FLORIDA STATE UNIV, DEPT OCEANOG, ENVIRONM RADIOACT MEASUREMENT FACIL, TALLAHASSEE, FL 32306 USA. NR 21 TC 13 Z9 13 U1 0 U2 3 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD SEP-OCT PY 1996 VL 101 IS 5 BP 707 EP 715 DI 10.6028/jres.101.069 PG 9 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA VY341 UT WOS:A1996VY34100009 PM 27805089 ER PT J AU Bendersky, LA Vanderah, TA Roth, RS AF Bendersky, LA Vanderah, TA Roth, RS TI Structural features of ''Ba4Fe4Ti3O16'' and ''Ba26Fe20Ti21O98'' as revealed by high-resolution electron microscopy SO JOURNAL OF SOLID STATE CHEMISTRY LA English DT Letter ID BARIUM POLYTITANATES; CRYSTAL-CHEMISTRY; PHASE-EQUILIBRIA; SYSTEM AB Preliminary results from high-resolution microscopy and electron diffraction studies of two new compounds with approximate compositions Ba4Fe4Ti3O16 (E phase) and Ba26Fe20Ti21O98 (M phase) are described. The compounds were found to be structurally related and exhibit two types of structural blocks. One of the blocks (H) is ordered with respect to the other by tripling within the basal hexagonal cell. Another block (P) is apparently perovskite-related. Phase E was found to have a well-ordered structure (space group either hexagonal P6 or trigonal P3), whereas phase M exhibits persistent and regularly occurring structural disorder as revealed by the presence of diffuse, continuous streaks. We suggest that the origin of this disorder is poor correlation in translation of the H blocks. (C) 1996 Academic Press,Inc. RP Bendersky, LA (reprint author), NIST,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899, USA. NR 5 TC 4 Z9 4 U1 0 U2 0 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0022-4596 J9 J SOLID STATE CHEM JI J. Solid State Chem. PD SEP PY 1996 VL 125 IS 2 BP 281 EP 284 DI 10.1006/jssc.1996.0299 PG 4 WC Chemistry, Inorganic & Nuclear; Chemistry, Physical SC Chemistry GA VG712 UT WOS:A1996VG71200027 ER PT J AU Searcy, AW Bullard, JW Carter, WC AF Searcy, AW Bullard, JW Carter, WC TI Possible explanations of transient neck formation between pairs of{100} faceted particles SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID GROWTH AB Rankin and Boatner have observed that {100} faceted MgO particles in contact along either corners or edges developed, on heating, necks that initially grew, but then shrank and broke, General thermodynamic models are provided that predict this transient neck formation for any cubic particles that share only a small fraction of an edge and for particles that share an edge that is less than 0.6 times as long as the orthogonal edges, A third model, which assumes that reaction of MgO particles with their carbon substrate removes MgO from the MgO-carbon interface at a constant rate, explains the observation that the neck shrinkage rate greatly exceeds the neck growth rate, Application of the theory to explaining the seeming prevalence of rounded surfaces in sintering powders is described. C1 UNIV CALIF BERKELEY,DEPT MAT SCI & MINERAL ENGN,BERKELEY,CA 94720. NIST,BLDG MAT DIV,GAITHERSBURG,MD 20899. NIST,DIV CERAM,GAITHERSBURG,MD 20899. RP Searcy, AW (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720, USA. RI Carter, W/K-2406-2012 NR 28 TC 5 Z9 5 U1 0 U2 2 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD SEP PY 1996 VL 79 IS 9 BP 2443 EP 2451 DI 10.1111/j.1151-2916.1996.tb08995.x PG 9 WC Materials Science, Ceramics SC Materials Science GA VJ727 UT WOS:A1996VJ72700029 ER PT J AU Liu, HY Hsu, SM AF Liu, HY Hsu, SM TI Fracture behavior of multilayer silicon nitride/boron nitride ceramics SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID INTERFACE; MODEL AB The fracture behavior of multilayer Si3N4/BN ceramics in bending has been studied, The materials were prepared by a process of tape casting, coating, laminating, and hot pressing, The Si3N4 layers were separated by thin, weak BN interlayers, Crack patterns in bending bars were examined with a scanning electron microscope. The weak layers deflected cracks in bending and thus prevented catastrophic failure, In one well-aligned multilayer ceramic A, a main crack propagated through the specimen although along a zigzag path, A second multilayer ceramic B was made to simulate a wood grain structure, Its failure was dominated by shear cracking along the weak BN layers, Besides crack deflection, interlock bridging between toothlike layers in the wake of the main crack appeared also to contribute to toughening. RP Liu, HY (reprint author), NIST,DIV CERAM,GAITHERSBURG,MD 20899, USA. NR 18 TC 124 Z9 143 U1 2 U2 31 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD SEP PY 1996 VL 79 IS 9 BP 2452 EP 2457 DI 10.1111/j.1151-2916.1996.tb08996.x PG 6 WC Materials Science, Ceramics SC Materials Science GA VJ727 UT WOS:A1996VJ72700030 ER PT J AU ZagozdzonWosik, W Korablev, K Rusakova, I Simons, D Shi, JH Chi, P Wolfe, JC AF ZagozdzonWosik, W Korablev, K Rusakova, I Simons, D Shi, JH Chi, P Wolfe, JC TI Formation of shallow junctions during rapid thermal processing from electron-beam deposited boron sources SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID SILICON; TECHNOLOGY; DIFFUSION; TRANSISTOR; SI AB Diffusion via rapid thermal processing (RTP) has been investigated for fabrication of shallow p-type layers doped with boron. We used dopant sources deposited by electron beam evaporation in the form of thin boron layers with or without in Situ deposited silicon capping films. The deposition process is compatible with the resist mask due to low temperatures and poor step coverage, which facilitate dopant removal via a lift-off process. Sheet resistance measurements together with secondary ion mass spectroscopy and spreading resistance profiling analyses indicate that doping efficiency is high for both types of sources in the temperature range of 900 to 1050 degrees C for 10 to 30 s. Full dopant activation in the silicon substrate, except for the surface region, has been recorded for all process conditions. High surface concentrations observed in the processed samples were attributed to a residual boron layer. Oxidation during doping via RTP results in diffusion enhancement and in consumption of the boron source. Results of cross-sectional transmission electron microscopy (TEM) analyses confirm fast oxide growth rates during the diffusion processes in an oxygen ambient. No defects within the doped layers have been found for the process conditions used in the experiments. C1 UNIV HOUSTON,TEXAS CTR SUPERCONDUCT,HOUSTON,TX 77204. NIST,GAITHERSBURG,MD 20899. SEMATECH,AUSTIN,TX 78741. RP ZagozdzonWosik, W (reprint author), UNIV HOUSTON,DEPT ELECT & COMP ENGN,HOUSTON,TX 77204, USA. NR 26 TC 0 Z9 0 U1 1 U2 1 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 10 SOUTH MAIN STREET, PENNINGTON, NJ 08534 SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD SEP PY 1996 VL 143 IS 9 BP 2981 EP 2989 DI 10.1149/1.1837136 PG 9 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA VH209 UT WOS:A1996VH20900059 ER PT J AU Dunn, ML Ledbetter, H Heyliger, PR Choi, CS AF Dunn, ML Ledbetter, H Heyliger, PR Choi, CS TI Elastic constants of textured short-fiber composites SO JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS LA English DT Article DE microstructures; anisotropic material; particle reinforced material; mechanical testing; nondestructive evaluation ID EFFECTIVE THERMAL-CONDUCTIVITY; MORI-TANAKA THEORY; REINFORCED COMPOSITES; HETEROGENEOUS MEDIA; DIFFERENTIAL SCHEME; EFFECTIVE STIFFNESS; EFFECTIVE MODULI; UNIFORM-FIELDS; AVERAGE STRESS; INCLUSIONS AB We studied the transversely isotropic elastic response of a series of textured short-fiber SiC/Al metal-matrix composites. By texture we mean the preferred orientation of the short fibers. We fully characterized the microstructure of the extruded SiC/Al short-fiber composites through a combination of mass-density measurements, optical and scanning electron microscopy, and neutron diffraction. We measured all components of the overall elastic-stiffness tensor of the composites using two methods: MHz-frequency pulse-echo ultrasonics and kHz-frequency acoustic-resonance spectroscopy, the latter being the first application of the method to short-fiber or particle-reinforced composites. We propose a relatively simple micromechanics model to predict the entire set of elastic constants, and give simple results for orientation distributions of practical significance. The predictions are in excellent agreement with measurements. Published by Elsevier Science Ltd C1 NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,BOULDER,CO 80303. COLORADO STATE UNIV,DEPT CIVIL ENGN,FT COLLINS,CO 80523. NATL INST STAND & TECHNOL,DIV REACTOR RADIAT,GAITHERSBURG,MD 20899. RP Dunn, ML (reprint author), UNIV COLORADO,CTR ACOUST MECH & MAT,DEPT MECH ENGN,BOULDER,CO 80309, USA. OI DUNN, MARTIN/0000-0002-4531-9176 NR 63 TC 39 Z9 40 U1 0 U2 8 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0022-5096 J9 J MECH PHYS SOLIDS JI J. Mech. Phys. Solids PD SEP PY 1996 VL 44 IS 9 BP 1509 EP & DI 10.1016/0022-5096(96)00021-X PG 32 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA VF629 UT WOS:A1996VF62900005 ER PT J AU Dube, P Ma, LS Ye, J Jungner, P Hall, JL AF Dube, P Ma, LS Ye, J Jungner, P Hall, JL TI Thermally induced self-locking of an optical cavity by overtone absorption in acetylene gas SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID SENSITIVE DETECTION; LINES; LASER; TIME AB Strong self-locking phenomena are observed when laser power is converted into heat by a weakly absorbing medium within a high-finesse cavity. Deposited heat leads to increased temperature and, for the case of weakly absorbing intracavity gases studied here, to an associated reduction of density and refractive index. This thermal change in refractive index provides self-acting cavity tuning near resonant conditions. In the experiments reported here a Fabry-Perot cavity of finesse 274 was filled with acetylene gas and illuminated with a titanium:sapphire laser tuned to the P(11) line of the nu(l) + 3 nu(3) overtone band near 790 nm. The dependencies of maximum frequency-locking range on gas pressure, laser power, and laser frequency sweep rate and direction were measured and could be well unified by analysis based on the thermal model. In the domain of strong self-tuning an interesting self-sustained oscillation was observed, with its several sharp frequencies directly and quantitatively linked to the acoustic boundary conditions in our cylindrical cell geometry. The differences between the behavior of acetylene near 790 nm and molecular oxygen with electronic transition near 763 nm are instructive; whereas the absorbed powers were similar, they differed strongly in their rates for internal to translational energy conversion by collisional relaxation. (C) 1996 Optical Society of America. C1 NIST,BOULDER,CO 80309. E CHINA NORMAL UNIV,DEPT PHYS,SHANGHAI 200062,PEOPLES R CHINA. RP Dube, P (reprint author), UNIV COLORADO,JILA,BOULDER,CO 80309, USA. RI Ye, Jun/C-3312-2011 NR 20 TC 17 Z9 17 U1 0 U2 1 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0740-3224 J9 J OPT SOC AM B JI J. Opt. Soc. Am. B-Opt. Phys. PD SEP PY 1996 VL 13 IS 9 BP 2041 EP 2054 DI 10.1364/JOSAB.13.002041 PG 14 WC Optics SC Optics GA VF898 UT WOS:A1996VF89800027 ER PT J AU Pei, P Malghan, SG Dapkunas, SJ Zajchowski, PH AF Pei, P Malghan, SG Dapkunas, SJ Zajchowski, PH TI Characterization and processing of spray-dried zirconia powders for plasma spray application SO JOURNAL OF THERMAL SPRAY TECHNOLOGY LA English DT Article DE binder content; plasma spray; powder characterization; powder performance correlation; thermal rupture test; yttria-stabilized zirconia powder; zirconia-based thermal barrier coatings AB The correlation between the performance of plasma spray coatings and feedstock powder properties is not fully understood, To demonstrate this correlation, eight spray-dried zirconia powders containing a mass fraction of 20 % Y2O3 (yttria) were characterized with respect to their physical, bulk chemical, and surface chemical properties, The same powders were plasma spray deposited as coatings, and their relative performance was evaluated using a thermal rupture test developed by Pratt and Whitney, The specific powder properties studied were chemical composition, binder content, particle size distribution, powder morphology, interface chemistry, thermogravimetry, phase composition, and specific surface area. Among the characterization data, the binder-related properties of the powder correlated most strongly with the thermal rupture test data, Specifically, higher binder contents were associated with poor thermal rupture test performance. C1 NIST,MAT SCI & ENGN LAB,DIV CERAM,GAITHERSBURG,MD 20899. UNITED TECHNOL CORP,PRATT & WHITNEY,E HARTFORD,CT 06108. NR 11 TC 0 Z9 0 U1 1 U2 1 PU ASM INTERNATIONAL PI MATERIALS PARK PA SUBSCRIPTIONS SPECIALIST CUSTOMER SERVICE, MATERIALS PARK, OH 44073-0002 SN 1059-9630 J9 J THERM SPRAY TECHN JI J. Therm. Spray Technol. PD SEP PY 1996 VL 5 IS 3 BP 343 EP 351 DI 10.1007/BF02645886 PG 9 WC Materials Science, Coatings & Films SC Materials Science GA VE123 UT WOS:A1996VE12300031 ER PT J AU Filippelli, AR AF Filippelli, AR TI Influence of envelope geometry on the sensitivity of ''nude'' ionization gauges SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article ID BAYARD-ALPERT GAUGE; VACUUM STANDARD AB This article presents the results of some measurements of the influence of envelope size and shape on the N-2 sensitivity of two nominally identical ''nude'' extractor ionization gauges, and three common ''nude'' versions of the Bayard-Alpert ionization gauge. Measurements were made over the pressure range 10(-7)-10(-1) Pa, using typical gauge operating parameters and with vacuum chamber and gauge envelope at ground potential. Sensitivity values corresponding to the three different envelopes used in this work differed by as much as a factor of 2 (comparing maximum value to minimum value for each gauge) for the Bayard-Alpert gauges. For the extractor gauges, the differences were as large as 7%. RP Filippelli, AR (reprint author), NIST,CHEM SCI & TECHNOL LAB,DIV THERMOPHYS,GAITHERSBURG,MD 20899, USA. NR 14 TC 2 Z9 2 U1 2 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD SEP-OCT PY 1996 VL 14 IS 5 BP 2953 EP 2957 DI 10.1116/1.580250 PG 5 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA VJ242 UT WOS:A1996VJ24200038 ER PT J AU Thompson, EF Chen, HS Hadley, LL AF Thompson, EF Chen, HS Hadley, LL TI Validation of numerical model for wind waves and swell in harbors SO JOURNAL OF WATERWAY PORT COASTAL AND OCEAN ENGINEERING-ASCE LA English DT Article ID BOUSSINESQ EQUATIONS; FORM AB The numerical wave model HARED has been used extensively within and outside the U.S. Army Corps of Engineers for estimating waves in harbors. The model was originally developed for long waves (harbor oscillations). It has been extended for use with short waves (wind waves and swell) and validated by several investigations, most notably Chen's (1986) fundamental investigation of long waves in a rectangular harbor. This study focuses on short-wave validation. The model is tested with several simple domains, in most cases with uniform depth. It is validated with laboratory data for irregular wave diffraction around a semi-infinite breakwater. Both broad and narrow directional spreads are considered. The model is also compared to widely accepted curves for regular and irregular wave diffraction through a breakwater gap. Field validation of the model for Kaumalapau Harbor, Lanai, Hawaii, is discussed. Tests demonstrate the effect of input parameters on model results and provide guidelines about the choice of parameter values in future modeling efforts. C1 DOC,NOAA,NWS,NCEP,CAMP SPRINGS,MD 20746. RP Thompson, EF (reprint author), USA,ENGINEER WATERWAYS EXPT STN,VICKSBURG,MS 39180, USA. NR 34 TC 14 Z9 14 U1 1 U2 2 PU ASCE-AMER SOC CIVIL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 SN 0733-950X J9 J WATERW PORT C-ASCE JI J. Waterw. Port Coast. Ocean Eng.-ASCE PD SEP-OCT PY 1996 VL 122 IS 5 BP 245 EP 257 DI 10.1061/(ASCE)0733-950X(1996)122:5(245) PG 13 WC Engineering, Civil; Engineering, Ocean; Water Resources SC Engineering; Water Resources GA VD976 UT WOS:A1996VD97600006 ER PT J AU Ehler, CN AF Ehler, CN TI South Florida: A laboratory for ecosystem restoration and integrated coastal management SO MARINE TECHNOLOGY SOCIETY JOURNAL LA English DT Article AB One of the largest efforts ever undertaken to restore any coastal and marine ecosystem in the world is unfolding today in South Florida. After more than a century of major modifications to the natural systems of the region, actions are being taken at all bevels of government to restore the natural resources and habitats that have been altered by human activities, primarily agriculture and urban development. While most public interest and attention have focused on restoring the terrestrial areas of ''the Everglades,'' more recently the scope of the problem has been enlarged to include Florida Bay and the Florida Keys. This paper describes recent efforts to restore and manage the coastal and marine areas of South Florida. RP Ehler, CN (reprint author), NOAA,NATL OCEAN SERV,SILVER SPRING,MD 20910, USA. NR 9 TC 2 Z9 2 U1 2 U2 5 PU MARINE TECHNOLOGY SOC INC PI WASHINGTON PA C/O I CLAYION MATTHEWS, 1828 L ST, NW, 9TH FL, WASHINGTON, DC 20036 SN 0025-3324 J9 MAR TECHNOL SOC J JI Mar. Technol. Soc. J. PD FAL PY 1996 VL 30 IS 3 BP 13 EP 20 PG 8 WC Engineering, Ocean; Oceanography SC Engineering; Oceanography GA VY731 UT WOS:A1996VY73100002 ER PT J AU Watson, KL AF Watson, KL TI Economic and health benefits of collaborative US-Mexico bioremediation of marine ecosystem projects SO MARINE TECHNOLOGY SOCIETY JOURNAL LA English DT Editorial Material RP Watson, KL (reprint author), NOAA,OFF GLOBAL PROGRAMS,SILVER SPRING,MD 20910, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MARINE TECHNOLOGY SOC INC PI WASHINGTON PA C/O I CLAYION MATTHEWS, 1828 L ST, NW, 9TH FL, WASHINGTON, DC 20036 SN 0025-3324 J9 MAR TECHNOL SOC J JI Mar. Technol. Soc. J. PD FAL PY 1996 VL 30 IS 3 BP 38 EP 39 PG 2 WC Engineering, Ocean; Oceanography SC Engineering; Oceanography GA VY731 UT WOS:A1996VY73100008 ER PT J AU Purcell, MK Kornfield, I Fogarty, M Parker, A AF Purcell, MK Kornfield, I Fogarty, M Parker, A TI Interdecadal heterogeneity in mitochondrial DNA of Atlantic haddock (Melanogrammus aeglefinus) from Georges Bank SO MOLECULAR MARINE BIOLOGY AND BIOTECHNOLOGY LA English DT Article ID RECRUITMENT VARIABILITY; CONTINENTAL-SHELF; MUSEUM SPECIMENS; GADUS-MORHUA; POPULATIONS; EVOLUTION; DYNAMICS; COD; DIFFERENTIATION; AMPLIFICATION AB Atlantic haddock of Georges Bank are characterized by large fluctuations in population size and a recent collapse of the commercial fishery. DNA extracted from dried scales of Georges Bank haddock, archived by the U.S. National Marine Fisheries Service (NMFS), reveals significant heterogeneity in frequencies of four mitochondrial DNA control region haplotypes between 1975 and 1985 cohorts. Several processes may be responsible for this temporal variation, the most attractive hypothesis being that haddock from other geographic regions episodically contribute to the Georges Bank gene pool. Thus, the population of haddock spawning on Georges Bank may not be genetically discrete and, with respect to Atlantic haddock, Georges Bank may not be viewed as a closed system. C1 UNIV MAINE,DEPT ZOOL,ORONO,ME 04469. UNIV MAINE,SCH MARINE SCI,ORONO,ME 04469. NOAA,NATL MARINE FISHERIES SERV,NE FISHERIES SCI CTR,WOODS HOLE,MA 02543. OI Purcell, Maureen/0000-0003-0154-8433 NR 42 TC 30 Z9 30 U1 0 U2 0 PU BLACKWELL SCIENCE INC PI CAMBRIDGE PA 238 MAIN ST, CAMBRIDGE, MA 02142 SN 1053-6426 J9 MOL MAR BIOL BIOTECH JI Mol. Mar. Biol. Biotechnol. PD SEP PY 1996 VL 5 IS 3 BP 185 EP 192 PG 8 WC Biotechnology & Applied Microbiology; Marine & Freshwater Biology SC Biotechnology & Applied Microbiology; Marine & Freshwater Biology GA VG849 UT WOS:A1996VG84900003 PM 8817925 ER PT J AU McCartney, MS Curry, RG Bezdek, HF AF McCartney, MS Curry, RG Bezdek, HF TI North Atlantic's transformation pipeline chills and redistributes subtropical water - But it's not a smooth process and it mightily affects climate SO OCEANUS LA English DT Article C1 NOAA,ATLANTIC OCEANOG & METEOROL LAB,MIAMI,FL 33149. RP McCartney, MS (reprint author), WOODS HOLE OCEANOG INST,DEPT PHYS OCEANOG,WOODS HOLE,MA 02543, USA. NR 0 TC 15 Z9 15 U1 1 U2 1 PU WOODS HOLE OCEANOGRAPHIC INST PI WOODS HOLE PA OCEANUS MAGAZINE, WOODS HOLE, MA 02543 SN 0029-8182 J9 OCEANUS JI Oceanus PD FAL-WIN PY 1996 VL 39 IS 2 BP 19 EP 23 PG 5 WC Oceanography SC Oceanography GA WF271 UT WOS:A1996WF27100009 ER PT J AU Pfister, O Murtz, M Wells, JS Hollberg, L Murray, JT AF Pfister, O Murtz, M Wells, JS Hollberg, L Murray, JT TI Division by 3 of optical frequencies by use of difference-frequency generation in noncritically phase-matched RbTiOAsO4 SO OPTICS LETTERS LA English DT Article ID ABSOLUTE-FREQUENCY; RYDBERG CONSTANT; LASER; TRANSITION; ION; HYDROGEN; KTP AB A new scheme for coherently connecting optical frequencies in a 3:1 ratio has been demonstrated. To phase lock a Nd:YAG laser at 1064 nm with a CO overtone laser at 3192 nm, we generated their difference frequency in RbTiOAsO4 (RTA) and beat it against the second harmonic of 3192 nm that was generated in AgGaSe2. C1 UNIV COLORADO,BOULDER,CO 80309. UNIV BONN,INST ANGEW PHYS,D-53115 BONN,GERMANY. UNIV ARIZONA,CTR OPT SCI,TUCSON,AZ 85721. RP Pfister, O (reprint author), NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309, USA. RI Pfister, Olivier/A-4924-2013 OI Pfister, Olivier/0000-0003-3386-9661 NR 23 TC 17 Z9 17 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD SEP 1 PY 1996 VL 21 IS 17 BP 1387 EP 1389 DI 10.1364/OL.21.001387 PG 3 WC Optics SC Optics GA VE310 UT WOS:A1996VE31000025 PM 19876361 ER PT J AU Bryant, GW Julienne, PS Band, YB AF Bryant, GW Julienne, PS Band, YB TI Exciton binding and delocalization in T-shaped quantum wires SO PHYSICA B LA English DT Article; Proceedings Paper CT 3rd International Symposium on New Phenomena in Mesoscopic Structures (NPMS 95) CY DEC 04-08, 1995 CL MAUI, HI SP Japan Soc Promot Sci, 151st Comm Electr Propert Extreme Struct DE quantum wires; excitons; binding energy; cleaved edge overgrowth AB Effective mass models with screened pair interaction give reasonable energies for excitons in T-shaped wires provided the effects of complex geometry are included. A sizable shift between exciton states in wells and T-shaped wires occurs due to enhancement in binding energy, confinement in the wires, and interwire coupling. C1 BEN GURION UNIV NEGEV,DEPT CHEM,IL-84105 BEER SHEVA,ISRAEL. BEN GURION UNIV NEGEV,DEPT PHYS,IL-84105 BEER SHEVA,ISRAEL. RP Bryant, GW (reprint author), NIST,GAITHERSBURG,MD 20899, USA. RI Julienne, Paul/E-9378-2012 OI Julienne, Paul/0000-0002-5494-1442 NR 6 TC 1 Z9 1 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD SEP PY 1996 VL 227 IS 1-4 BP 390 EP 392 DI 10.1016/0921-4526(96)00450-4 PG 3 WC Physics, Condensed Matter SC Physics GA VR715 UT WOS:A1996VR71500102 ER PT J AU Moodenbaugh, AR Fischer, DA Wang, YL Fukumoto, Y AF Moodenbaugh, AR Fischer, DA Wang, YL Fukumoto, Y TI Superconductivity, oxygen content, and hole state density in Bi2Sr1.75Ca1.25Cu2O8.18+y (-0.093d excitation of Sc-like barium Ba35+ and Ti-like barium Ba34+ are calculated and compared with a recent electron beam ion trap experiment at the National Institute of Standards and Technology. Assuming a fractional population of Ba35+ in the trap of about 30%, we obtain good agreement between theory and experiment for the cross section ratio sigma(DR)/sigma(RR)(n=4), as well as for sigma(RR)(n=5)/sigma RR)(n=4). The result confirms again that the simple angular momentum averaged procedure can be effective in treating DR for heavy open-shell ions when the energy resolution is not high. A large, broad peak below 2 keV in the x-ray spectrum is being theoretically examined. C1 UNIV CONNECTICUT, DEPT PHYS, STORRS, CT 06269 USA. NATL INST STAND & TECHNOL, DEPT PHYS, GAITHERSBURG, MD 20899 USA. RP UNIV HARTFORD, DEPT PHYS, W HARTFORD, CT 06117 USA. NR 22 TC 16 Z9 17 U1 0 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9926 EI 2469-9934 J9 PHYS REV A JI Phys. Rev. A PD SEP PY 1996 VL 54 IS 3 BP 2040 EP 2049 DI 10.1103/PhysRevA.54.2040 PG 10 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA VH090 UT WOS:A1996VH09000040 ER PT J AU Walhout, M Sterr, U Rolston, SL AF Walhout, M Sterr, U Rolston, SL TI Magnetic inhibition of polarization-gradient laser cooling in sigma(+)-sigma(-) optical molasses SO PHYSICAL REVIEW A LA English DT Article ID DOPPLER LIMIT; MAGNETOOPTICAL TRAP; METASTABLE XENON; ATOMS; TEMPERATURE; RESONANCE; FOUNTAIN; FIELD AB Xenon atoms are released from a magneto-optical trap and equilibrate in a one-dimensional, sigma(+)-sigma(-) optical molasses, along which a uniform magnetic field is applied. In the rest frame of the ''corkscrew'' pattern of laser polarization, the magnetic field induces a nonzero average atomic velocity. Introducing a moving molasses through a relative difference in the two laser-beam frequencies allows straightforward, accurate measurements of the molasses-frame velocity distribution over a large range of magnetic fields. The measurements reveal the loss of polarization-gradient cooling in fields higher than similar to 0.2 mT, in quantitative agreement with theoretical predictions. C1 UNIV HANNOVER,INST QUANTUM OPT,D-30167 HANNOVER,GERMANY. RP Walhout, M (reprint author), US DEPT COMMERCE,NATL INST STAND & TECHNOL,ATOM PHYS DIV,BLDG 221 ROOM A 167,GAITHERSBURG,MD 20899, USA. RI rolston, steven/L-5175-2013 OI rolston, steven/0000-0003-1671-4190 NR 21 TC 15 Z9 16 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD SEP PY 1996 VL 54 IS 3 BP 2275 EP 2279 DI 10.1103/PhysRevA.54.2275 PG 5 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA VH090 UT WOS:A1996VH09000068 ER PT J AU Geltman, S AF Geltman, S TI Multiple ionization of argon atoms by intense laser pulses SO PHYSICAL REVIEW A LA English DT Article ID FIELD DOUBLE-IONIZATION; HELIUM AB We have analyzed the recently measured single, double, and triple ionization of Ar by strong laser pulses in terms of an independent-electron model. An excellent fit to the highest intensity data is obtained in terms of two single-electron ionization probabilities that correspond to the initial 3p bound orbitals being in the m=0 or +/-1 substates. Their relative magnitudes are understood in terms of the tunneling of electrons that are in differently oriented bound orbits, and they both exhibit the expected approach to unity as the limiting over-the-barrier electron ejection is realized. The n-electron ionization probabilities go through maxima and crossings at the highest intensities that are well described by the independent-electron model. C1 NATL INST STAND & TECHNOL,BOULDER,CO 80309. RP Geltman, S (reprint author), UNIV COLORADO,JILA,BOULDER,CO 80309, USA. NR 8 TC 10 Z9 10 U1 0 U2 5 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD SEP PY 1996 VL 54 IS 3 BP 2489 EP 2491 DI 10.1103/PhysRevA.54.2489 PG 3 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA VH090 UT WOS:A1996VH09000094 ER PT J AU Fong, HF Keimer, B Reznik, D Milius, DL Aksay, IA AF Fong, HF Keimer, B Reznik, D Milius, DL Aksay, IA TI Polarized and unpolarized neutron-scattering study of the dynamical spin susceptibility of YBa2Cu3O7 SO PHYSICAL REVIEW B LA English DT Article ID SUPERCONDUCTING ORDER-PARAMETER; MAGNETIC EXCITATIONS; HEISENBERG-ANTIFERROMAGNET; TEMPERATURE; LATTICE; PHONON; DEPENDENCE; VIBRATIONS; MODEL; GAP AB We report an extensive study of magnetic excitations in fully oxygenated YBa2Cu3O7, using neutron scattering with and without spin polarization analysis. By calibrating the measured magnetic intensity against calculated structure factors of optical phonons and against antiferromagnetic spin waves measured in the same crystal after deoxygenation to YBa2Cu3O6.2, we establish an absolute intensity scale for the dynamical spin susceptibility, chi ''(q,omega). The integrated spectral weight of the sharp magnetic resonance at h omega=40 meV and q(parallel to)=(pi/a,pi/a) in the superconducting state is integral d(h omega)chi(res)''(q,w)=(0.52+/-0.1) at low temperatures. The energy and spectral weight of the resonance are measured up to T=0.8T(c). The resonance disappears in the normal state, and a conservative upper limit of 30 states/eV is established for the normal state dynamical susceptibility at q(parallel to)=(pi/a,pi/a) and 10 meV less than or equal to h omega less than or equal to 40 meV. Our results are compared to previous neutron-scattering data on YBa2Cu3O7, theoretical interpretations of NMR data and current models of the 40 meV resonance. C1 BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. NIST,GAITHERSBURG,MD 20899. PRINCETON UNIV,DEPT CHEM ENGN,PRINCETON,NJ 08544. RP Fong, HF (reprint author), PRINCETON UNIV,DEPT PHYS,PRINCETON,NJ 08544, USA. RI Aksay, Ilhan/B-9281-2008 NR 47 TC 120 Z9 120 U1 1 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD SEP 1 PY 1996 VL 54 IS 9 BP 6708 EP 6720 DI 10.1103/PhysRevB.54.6708 PG 13 WC Physics, Condensed Matter SC Physics GA VG949 UT WOS:A1996VG94900099 ER PT J AU Hinaus, BM Rzchowski, MS Heinig, N Cai, XY Kaiser, DL AF Hinaus, BM Rzchowski, MS Heinig, N Cai, XY Kaiser, DL TI Phase-sensitive tunneling measurements in a bulk YBa2Cu3O7-delta dc SQUID SO PHYSICAL REVIEW B LA English DT Article ID SUPERCONDUCTING ORDER-PARAMETER; PAIRING STATE; SYMMETRY; JUNCTIONS; PB AB We use Josephson tunneling in a bulk YBa2Cu3O7-delta bicrystal SQUID to investigate methods of determining the order parameter symmetry from transport measurements. We discuss procedures designed to eliminate the effects of self-fields due to transport currents in the sample, and apply these methods to our experimental system. The bulk bicrystal SQUID is designed to give zero phase shift in the event of pure s- or d-wave symmetry, and hence is an ideal experimental test of our analysis procedures. We find a method exploiting the time-reversal invariance of the SQUID equations (independent of the gap time-reversal properties) to be most useful. C1 UNIV WISCONSIN,CTR APPL SUPERCONDUCT,MADISON,WI 53706. UNIV WISCONSIN,DEPT MAT SCI,MADISON,WI 53706. NATL INST STAND & TECHNOL,DIV CERAM,GAITHERSBURG,MD 20899. RP Hinaus, BM (reprint author), UNIV WISCONSIN,DEPT PHYS,1150 UNIV AVE,MADISON,WI 53706, USA. NR 18 TC 2 Z9 2 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD SEP 1 PY 1996 VL 54 IS 9 BP 6770 EP 6775 DI 10.1103/PhysRevB.54.6770 PG 6 WC Physics, Condensed Matter SC Physics GA VG949 UT WOS:A1996VG94900107 ER PT J AU Harris, VG Kemner, KM Das, BN Koon, NC Ehrlich, AE Kirkland, JP Woicik, JC Crespo, P Hernando, A Escorial, AG AF Harris, VG Kemner, KM Das, BN Koon, NC Ehrlich, AE Kirkland, JP Woicik, JC Crespo, P Hernando, A Escorial, AG TI Near-neighbor mixing and bond dilation in mechanically alloyed Cu-Fe SO PHYSICAL REVIEW B LA English DT Article ID SOLID-STATE AMORPHIZATION; ABSORPTION FINE-STRUCTURE; X-RAY-SCATTERING; MAGNETIC-PROPERTIES; GIANT MAGNETORESISTANCE; IMMISCIBLE ELEMENTS; SYSTEM; ORDER; HEAT; BCC AB Extended x-ray-absorption fine-structure (EXAFS) measurements were used to obtain element-specific, structural, and chemical information of the local environments around Cu and Fe atoms in high-energy ball-milled CuxFe1-x samples (x=0.50 and 0.70). Analysis of the EXAFS data shows both Fe and Cu atoms reside in face-centered-cubic sites where the first coordination sphere consists of a mixture of Fe and Cu atoms in a ratio which reflects the as-prepared stoichiometry. The measured bond distances indicate a dilation in the bonds between unlike neighbors which accounts for the lattice expansion measured by x-ray diffraction. These results indicate that metastable alloys having a positive heat of mixing can be prepared via the high-energy ball-milling process. C1 SFA INC,LANDOVER,MD 20785. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. INST MAGNETISMO APLICADO,MADRID 28230,SPAIN. CSIC,CTR NACL INVEST MET,E-28040 MADRID,SPAIN. RP Harris, VG (reprint author), USN,RES LAB,WASHINGTON,DC 20375, USA. RI Harris, Vincent/A-8337-2009; Hernando, Antonio/E-2105-2015; OI GARCIA-ESCORIAL, Asuncion/0000-0002-7127-5816 NR 56 TC 48 Z9 49 U1 2 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD SEP 1 PY 1996 VL 54 IS 10 BP 6929 EP 6940 DI 10.1103/PhysRevB.54.6929 PG 12 WC Physics, Condensed Matter SC Physics GA VH082 UT WOS:A1996VH08200031 ER PT J AU Xu, GY DiTusa, JF Ito, T Oka, K Takagi, H Broholm, C Aeppli, G AF Xu, GY DiTusa, JF Ito, T Oka, K Takagi, H Broholm, C Aeppli, G TI Y2BaNiO5: A nearly ideal realization of the S=1 Heisenberg chain with antiferromagnetic interactions SO PHYSICAL REVIEW B LA English DT Article ID TRANSITION-METAL OXIDE; QUANTUM SPIN CHAINS; HALDANE-GAP; MONTE-CARLO; STRUCTURAL CHARACTERIZATION; ENERGY-GAP; DYNAMICS; EXCITATIONS; SYSTEM; AGVP2S6 AB We report an inelastic-neutron-scattering experiment on single crystals of the one-dimensional spin-one antiferromagnet Y2BaNiO5. The data show that this compound is a nearly ideal material for studying the Haldane conjecture in the Heisenberg limit. In particular, the Haldane gap at (q) over tilde = pi is almost isotropic, taking on the values of 7.5(1), 8.6(1), and 9.6(1) meV for polarizations parallel to the three principal orthorhombic axes respectively. Interchain coupling along the edges of the orthorhombic unit cell is found to be very weak (J'/J less than or equal to 5 x 10(-4)). Finally, we show that defects in our sample at the 1% level cause visible broadening of the excitation at (q) over tilde = pi. C1 LOUISIANA STATE UNIV,DEPT PHYS & ASTRON,BATON ROUGE,LA 70803. ELECTROTECH LAB,TSUKUBA,IBARAKI 305,JAPAN. UNIV TOKYO,INST SOLID STATE PHYS,TOKYO 106,JAPAN. JOHNS HOPKINS UNIV,DEPT PHYS & ASTRON,BALTIMORE,MD 21218. NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. NEC RES INST,PRINCETON,NJ 08540. RP Xu, GY (reprint author), JOHNS HOPKINS UNIV,DEPT PHYS & ASTRON,BALTIMORE,MD 21218, USA. RI Takagi, Hidenori/B-2935-2010; Broholm, Collin/E-8228-2011; Xu, Guangyong/A-8707-2010 OI Broholm, Collin/0000-0002-1569-9892; Xu, Guangyong/0000-0003-1441-8275 NR 39 TC 91 Z9 91 U1 1 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD SEP 1 PY 1996 VL 54 IS 10 BP R6827 EP R6830 PG 4 WC Physics, Condensed Matter SC Physics GA VH082 UT WOS:A1996VH08200007 ER PT J AU Douglas, JF AF Douglas, JF TI Swelling and growth of polymers, membranes, and sponges SO PHYSICAL REVIEW E LA English DT Review ID SELF-AVOIDING SURFACES; DIFFUSION-LIMITED AGGREGATION; MOLECULAR-DYNAMICS SIMULATIONS; GRAPHITE OXIDE MEMBRANES; PLANAR RANDOM SURFACES; TETHERED MEMBRANES; BRANCHED POLYMERS; LATTICE ANIMALS; MONTE-CARLO; STATISTICAL-MECHANICS AB Polymers can be formed into a wide range of structures depending on the monomer chemistry and the kinetic conditions of growth. A general model of polymers having higher-order connectivity is introduced that reduces to flexible linear polymers, membranes, and sponges as special cases. This ''Wiener sheet'' model, which extends the conventional Wiener path model of linear polymers, is argued to describe various classes of branched polymers, as well as different types of interacting random surfaces. For example, lattice animals and percolation clusters are considered to be perforated sheets whose large-scale dimensions are described by the Wiener sheet model with excluded volume interactions. To within the approximations of the model calculations, the properties of the Wiener sheet ''membrane'' are consistent with this correspondence. The influence of the excluded volume and the kinetics of growth of membrane and sponge structures are treated at a Flory-level approximation, although the Wiener sheet model should admit to a renormalization-group treatment as in the case of linear polymers; Predictions of the self-interacting Wiener sheet model are contrasted with an alternative and complementary random surface model introduced by Nelson and co-workers and are compared with recent simulations and experiment. RP Douglas, JF (reprint author), NATL INST STAND & TECHNOL,DIV POLYMERS,GAITHERSBURG,MD 20899, USA. NR 149 TC 23 Z9 23 U1 1 U2 13 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD SEP PY 1996 VL 54 IS 3 BP 2677 EP 2689 DI 10.1103/PhysRevE.54.2677 PG 13 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA VK265 UT WOS:A1996VK26500070 ER PT J AU Franaszek, M AF Franaszek, M TI Cutoff frequency of experimentally generated noise: A Melnikov approach SO PHYSICAL REVIEW E LA English DT Article ID COLORED NOISE; SYSTEMS AB The motion of an overdamped particle excited by colored noise in a bistable potential is discussed in chaotic dynamics terms. A Melnikov approach is used to determine an appropriate cutoff frequency of experimentally generated noise as a function of noise correlation time. C1 CRACOW PEDAGOG UNIV,INST PHYS,KRAKOW,POLAND. RP Franaszek, M (reprint author), NIST,BLDG & FIRE RES LAB,BLDG 226,GAITHERSBURG,MD 20899, USA. NR 12 TC 0 Z9 0 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD SEP PY 1996 VL 54 IS 3 BP 3003 EP 3005 DI 10.1103/PhysRevE.54.3003 PG 3 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA VK265 UT WOS:A1996VK26500110 ER PT J AU Hubbell, JH AF Hubbell, JH TI Arthur Charlesby - 1915-1996 - Obituary SO RADIATION PHYSICS AND CHEMISTRY LA English DT Biographical-Item RP Hubbell, JH (reprint author), NATL INST STAND & TECHNOL, RM C-312, RADIAT PHYS BLDG 245, GAITHERSBURG, MD 20899 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB J9 RADIAT PHYS CHEM JI Radiat. Phys. Chem. PD SEP PY 1996 VL 48 IS 3 BP R10 EP R10 DI 10.1016/S0969-806X(96)90006-7 PG 1 WC Chemistry, Physical; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical SC Chemistry; Nuclear Science & Technology; Physics GA VH305 UT WOS:A1996VH30500006 ER PT J AU Marinenko, RB Bright, DS Bernik, S AF Marinenko, RB Bright, DS Bernik, S TI Multiphase analysis of Bi-Sr-Ca-Cu-O high Tc superconductors with X-ray compositional mapping SO SCANNING LA English DT Article DE BSCCO high Tc superconductors; electron microprobe; image processing; phase identification; wavelength dispersive spectrometry compositional x-ray mapping ID ELECTRON-PROBE MICROANALYZER; PHASE AB Ba-Sr-Ca-Cu-O (BSCCO) high Tc superconductor specimens were prepared as part of a solid-solubility study in the region of the 2223 phase. The identification and determination of the amount of each phase in the final products were necessary. Quantitative digital x-ray compositional mapping with the electron microprobe was done with five wave wavelength spectrometers, one for each of the cations. To facilitate phase identification and quantification, image processing rules were developed for the nine possible phases, with each assigned a unique color. Using this procedure, at least six different phases were identified. Examples are cited in color. C1 JOZEF STEFAN INST,DEPT CERAM,LJUBLJANA,SLOVENIA. RP Marinenko, RB (reprint author), NIST,CHEM SCI & TECHNOL LAB,BLDG 222,RM A113,GAITHERSBURG,MD 20899, USA. NR 12 TC 5 Z9 5 U1 0 U2 0 PU FAMS INC PI MAHWAH PA BOX 832, MAHWAH, NJ 07430 SN 0161-0457 J9 SCANNING JI Scanning PD SEP PY 1996 VL 18 IS 6 BP 395 EP 400 PG 6 WC Instruments & Instrumentation; Microscopy SC Instruments & Instrumentation; Microscopy GA VG206 UT WOS:A1996VG20600001 ER PT J AU Weetall, HH McCurley, MF AF Weetall, HH McCurley, MF TI Proceedings of the sixth international meeting on chemical sensors Gaithersburg, MD, USA, 22-25 July 1996 .1. SO SENSORS AND ACTUATORS B-CHEMICAL LA English DT Editorial Material RP Weetall, HH (reprint author), NIST,DIV BIOTECHNOL,GAITHERSBURG,MD 20899, USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-4005 J9 SENSOR ACTUAT B-CHEM JI Sens. Actuator B-Chem. PD SEP PY 1996 VL 35 IS 1-3 BP 1 EP 10 DI 10.1016/S0925-4005(96)02005-9 PG 10 WC Chemistry, Analytical; Electrochemistry; Instruments & Instrumentation SC Chemistry; Electrochemistry; Instruments & Instrumentation GA WB681 UT WOS:A1996WB68100001 ER PT J AU Monfray, P Ramonet, M Beardsmore, D AF Monfray, P Ramonet, M Beardsmore, D TI Longitudinal and vertical CO2 gradients over the subtropical/subantarctic oceanic sink SO TELLUS SERIES B-CHEMICAL AND PHYSICAL METEOROLOGY LA English DT Article; Proceedings Paper CT Symposium on the Breathing of the Earth - Observational Constraints for Models of the Terrestrial Biosphere, at the IUGG XXI General Assembly CY JUL 02-14, 1995 CL BOULDER, CO SP IUGG ID ATMOSPHERIC CARBON-DIOXIDE; TRANSPORT MODEL; TROPOSPHERE; EXCHANGE; REGION AB The North-South gradient of atmospheric CO2 is commonly used to infer the latitudinal distribution of sources and sinks at the earth surface. Here we analyze the East-West and vertical gradients occurring at regional scale over the subtropical/subantarctic ocean (around 30 degrees S-45 degrees S), which is known to be the major sink of the southern hemisphere. Using French and Australian inter calibrated datasets, we find a significant depletion of atmospheric CO2 near Tasmania (Cape Grim, 40 degrees 41'S, 144 degrees 41'E, CGO) compared to the open Indian Ocean (Amsterdam Is., 37 degrees 48'S, 77 degrees 32'E, AMS). This depletion was about -0.4 +/- 0.2 ppmv for the 1988-1992 period. For the same period, CGO values were also depleted by -0.85 +/- 0.25 ppmv and -1.1 +/- 0.4 ppmv relative to the mid- and high-troposphere. Using a 3-D atmospheric transport model based on meteorological analysis, and a diagnostic CO2 flux scenario updated for the year 1990, we investigate the respective role of industrial, oceanic and biospheric fluxes. The main component which can explain such longitudinal and vertical oceanic sink appears to be the subtropical/subantarctic oceanic sink and its regional patterns. Using the oceanographic datasets in the Atlantic, Pacific, and West Indian oceans, we can reconstruct more than half of vertical gradient observed over CGO, but not the CGO depletion relative to AMS. Finally, we discuss the hypothesis of an extra oceanic CO2 sink south of the Australian mainland. C1 CSIRO,DIV ATMOSPHER RES,MORDIALLOC,VIC 3195,AUSTRALIA. NOAA,CLIMATE MONITORING & DIAGNOST LAB,BOULDER,CO 80303. RP Monfray, P (reprint author), CEA,CNRS,CTR FAIBLES RADIOACT,F-91198 GIF SUR YVETTE,FRANCE. NR 44 TC 9 Z9 9 U1 1 U2 1 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0280-6509 J9 TELLUS B JI Tellus Ser. B-Chem. Phys. Meteorol. PD SEP PY 1996 VL 48 IS 4 BP 445 EP 456 DI 10.1034/j.1600-0889.1996.t01-3-00004.x PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VP642 UT WOS:A1996VP64200004 ER PT J AU Bousquet, P Ciais, P Monfray, P Balkanski, Y Ramonet, M Tans, P AF Bousquet, P Ciais, P Monfray, P Balkanski, Y Ramonet, M Tans, P TI Influence of two atmospheric transport models on inferring sources and sinks of atmospheric CO2 SO TELLUS SERIES B-CHEMICAL AND PHYSICAL METEOROLOGY LA English DT Article; Proceedings Paper CT Symposium on the Breathing of the Earth - Observational Constraints for Models of the Terrestrial Biosphere, at the IUGG XXI General Assembly CY JUL 02-14, 1995 CL BOULDER, CO SP IUGG ID GENERAL-CIRCULATION MODEL; CARBON-DIOXIDE; LATITUDINAL DISTRIBUTION; INVERSION; SCHEME AB Atmospheric transport models are a source of uncertainty in the diagnostics of the CO2 sources and sinks. We propose here a protocol to compare two transport models: a 2-dimensional (2D) and a 3-dimensional (3D) model based on 3 different experiments that reveal the ability of each model to account for the different components of the atmospheric carbon cycle. The 2D model we use is the one described by Tans et al. and the 3D model is the TM2 model, developed by Heimann et al. First, we conduct the same fossil fuel experiment in both models and show that the 2D model has a stronger inter-hemispheric mixing than the 3D model (similar to 25%), even though the 2D model presents a weaker intra-hemispheric mixing above source regions (experiment A). The influence of year-to-year variability of transport on the latitudinal profile in fossil-fuel CO2 appears to be weak for the 1990s. We then use a set of ''all but fossil fuel'' fluxes, originally inferred from the 2D model, as an input to the 3D model (experiment B). Even if the main discrepancy on the resulting latitudinal CO2 concentrations occurs between the 2D and 3D models in the tropics and at the mid-northern latitudes, the differences implied by three longitudinal distributions tested in the 3D model are important and can be explained by a few global transport mechanisms. Finally, we quantify the differences in latitudinal CO2 concentrations observed in experiment B in terms of net carbon fluxes at the surface. To do so, an inverse calculation of the CO2 fluxes in latitude and time is performed with the 3D model, using as an input a smoothed latitudinal profile of atmospheric measurements for the period 1990-1993 (experiment C=A+B). We find with the 3D model that, averaged on the period 1990-93, the equatorial release is reduced by 40 Tmol yr(-1) (roughly 25% of the original source) compared with the initial 2D budget and is shifted southward by roughly 10 degrees. The mid northern latitude sink is also reduced by 80 Tmol yr(-1) (roughly 25% of the original sink). In summary, this study shows that the changes in the carbon budget required when moving from the 2D model to this 3D model are important, but they are not radical changes. C1 CENS,LAB MODELISAT CLIMAT & ENVIRONM,F-91191 GIF SUR YVETTE,FRANCE. NOAA,CLIMATE MONITORING & DIAGNOST LAB,BOULDER,CO 80303. RP Bousquet, P (reprint author), CNRS,CTR FAIBLES RADIOACT,1 AV DE LA TERRASSE,F-91198 GIF SUR YVETTE,FRANCE. RI Balkanski, Yves/A-6616-2011 OI Balkanski, Yves/0000-0001-8241-2858 NR 35 TC 16 Z9 16 U1 0 U2 2 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0280-6509 J9 TELLUS B JI Tellus Ser. B-Chem. Phys. Meteorol. PD SEP PY 1996 VL 48 IS 4 BP 568 EP 582 DI 10.1034/j.1600-0889.1996.t01-2-00011.x PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VP642 UT WOS:A1996VP64200011 ER PT J AU Dyukova, TV Lukashev, EP AF Dyukova, TV Lukashev, EP TI Dehydration effects on D96N bacteriorhodopsin films SO THIN SOLID FILMS LA English DT Letter DE bacteriorhodopsin; D96N mutant; gelatin films; biomaterials; multilayers; optical spectroscopy; water ID PURPLE MEMBRANE; WATER AB Dehydration effects on gelatin films of the D96N mutant bacteriorhodopsin (BR) and wild-type BR were studied. Unlike the wild-type BR films, wherein dehydration to 12% humidity results in an approximate 200-fold increase in the lifetime of the M state, D96N BR films dehydrated to the same extent have been shown to exhibit only a 17- to 20-fold increase in the lifetime of the M state. Chemically-enhanced D96N BR films possess a total bleaching efficiency of the initial-to-M;state transition that is close to theoretical maximum (1.0) over a wide range of relative humidity (35 to 85%). This provides an additional benefit to the D96N BR films as a material for storage and retrieval of optical information. C1 RUSSIAN ACAD SCI,INST THEORET & EXPT BIOPHYS,PUSHCHINO 142292,MOSCOW,RUSSIA. MOSCOW MV LOMONOSOV STATE UNIV,FAC BIOL,DEPT BIOPHYS,MOSCOW 119899,RUSSIA. RP Dyukova, TV (reprint author), NATL INST STAND & TECHNOL,A353-222,GAITHERSBURG,MD 20899, USA. NR 16 TC 14 Z9 14 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD SEP 1 PY 1996 VL 283 IS 1-2 BP 1 EP 4 DI 10.1016/0040-6090(95)08528-9 PG 4 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA VP001 UT WOS:A1996VP00100001 ER PT J AU Winans, GA Aebersold, PB Waples, RS AF Winans, GA Aebersold, PB Waples, RS TI Allozyme variability of Oncorhynchus nerka in the Pacific Northwest, with special consideration to populations of Redfish Lake, Idaho SO TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY LA English DT Article ID SOCKEYE-SALMON; CHINOOK SALMON; PINK SALMON; IDENTIFICATION; GENETICS; FORMS; ASIA AB We resolved allozyme variation among 28 enzymes encoded by 58 protein loci in 27 samples of sockeye salmon and kokanee Oncorhynchus nerka in the Pacific Northwest. Of 32 polymorphic loci, 16 were polymorphic at the P-0.95 level (frequency of the common allele less than or equal to 0.95). We found substantial variation at mAAT-1* and mAH-1,2*, loci not previously described in O. nerka in this portion of its distribution. Mean heterozygosity per sample ranged from 0.010 to 0.036 and averaged 0.028 over all samples. Wright's fixation index (F-ST) averaged 0.153 over 16 P-0.95 loci, indicating considerable allele frequency variation among samples. The pattern of population differentiation of sockeye salmon, as revealed through genetic distance and principal component analyses, resembled a mosaic in that nearest geographic neighbors were not necessarily similar genetically. Allele frequencies at two to five loci differed significantly between sympatric sockeye salmon and kokanee in three separate localities, indicating genetic and reproductive distinctiveness of the two sympatric forms. Sockeye salmon from Redfish Lake (Sawtooth Valley, Idaho) were of particular interest because of their extensive freshwater migration and extremely low abundance in recent years. We found no evidence that any of the recorded stock transfers of O. nerka into the Sawtooth Valley (Redfish and Alturas lakes) have had a genetic impact on populations surveyed here. The O. nerka from Sawtooth Valley presently occupy a distinctive position in multilocus space, particularly with respect to mAH-1,2*, mAAT-1*, and ALAT*. Continued studies of O. nerka in the Sawtooth Valley are focusing on juvenile outmigrants and ''residual'' sockeye salmon. RP Winans, GA (reprint author), NOAA,NATL MARINE FISHERIES SERV,NW FISHERIES SCI CTR,COASTAL ZONE & ESTUARINE STUDIES DIV,SEATTLE,WA 98112, USA. RI Waples, Robin/K-1126-2016 NR 61 TC 43 Z9 43 U1 0 U2 0 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE SUITE 110, BETHESDA, MD 20814-2199 SN 0002-8487 J9 T AM FISH SOC JI Trans. Am. Fish. Soc. PD SEP PY 1996 VL 125 IS 5 BP 645 EP 663 DI 10.1577/1548-8659(1996)125<0645:AVONIT>2.3.CO;2 PG 19 WC Fisheries SC Fisheries GA VJ089 UT WOS:A1996VJ08900002 ER PT J AU Prager, MH Goodyear, CP Scott, GP AF Prager, MH Goodyear, CP Scott, GP TI Application of a surplus production model to a swordfish-like simulated stock with time-changing gear selectivity SO TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY LA English DT Article ID HAKE; AGE AB Should a surplus production model be applied to a stock that exhibits pronounced age structure? Should it be applied to a stock that has experienced changing fishing mortality rates on fish of different sizes over time (i.e., changing selectivity)? These questions are of general interest to those engaged in stock assessment and of particular interest in the assessment of North Atlantic swordfish Xiphias gladius. In an attempt to answer them, we simulated an age-structured population, with fishery, similar to that of swordfish in the North Atlantic. The 30-year simulation included biological characteristics from the literature on swordfish and simulated fishing with increasing mortality of young fish over time; simulated catches approximated the actual catches of swordfish from 1962 through 1991. We fit a lumped-biomass, dynamic surplus production model to summary non-age-structured data from the simulated fishery. The resulting parameter estimates were compared to management benchmarks, including maximum sustainable yield (MSY), computed by age-structured methods from the growth and recruitment characteristics of the underlying simulation. The changing selectivity resulted in a small (<10%) decrease in MSY from the beginning of the series to its end; estimates from the production model were close to these underlying MSY values. Nine additional population trajectories were simulated with the same biological characteristics but other fishing histories; in most cases, the production model provided qualitatively correct estimates of stock status. Two new reliability statistics appear to be of value in judging the quality of production model fits. We conclude that for stocks similar to swordfish, the presence of strong age structure and moderate changes in selectivity should not proscribe the application of simple production models. C1 NATL MARINE FISHERIES SERV,SE FISHERIES SCI CTR,MIAMI,FL 33149. RP Prager, MH (reprint author), NATL MARINE FISHERIES SERV,SW FISHERIES SCI CTR,3150 PARADISE DR,TIBURON,CA 94920, USA. NR 24 TC 11 Z9 12 U1 0 U2 3 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE SUITE 110, BETHESDA, MD 20814-2199 SN 0002-8487 J9 T AM FISH SOC JI Trans. Am. Fish. Soc. PD SEP PY 1996 VL 125 IS 5 BP 729 EP 740 DI 10.1577/1548-8659(1996)125<0729:AOASPM>2.3.CO;2 PG 12 WC Fisheries SC Fisheries GA VJ089 UT WOS:A1996VJ08900008 ER PT J AU Grimes, CB Isley, JJ AF Grimes, CB Isley, JJ TI Influence of size-selective mortality on growth of gulf menhaden and king mackerel larvae SO TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY LA English DT Article ID SALMON ONCORHYNCHUS-KETA; OTOLITH MICROSTRUCTURE; MARINE FISH; BREVOORTIA-PATRONUS; NORTHERN GULF; PREDATION; AGE; SURVIVAL; MODEL; ZOOPLANKTON AB Gulf menhaden Brevoortia patronus and king mackerel Scomberomorus cavalla represent two widely different larval life history strategies: feeding on large and small prey, respectively. We back-calculated lengths at age for wild and laboratory-reared larvae of gulf menhaden and wild king mackerel using direct proportion procedures then constructed matrices of observed age (rows) by increment number (columns) for mean back-calculated lengths at age. The coefficient of variation (100 . SD/mean) in length at age was greater for observed than for back-calculated length at age for both wild and laboratory-reared gulf menhaden and for king mackerel. Columns in the length-at-age matrix of wild gulf menhaden showed significant trends of increasing backcalculated length at age for older larvae, but the matrix for laboratory-reared fish did not. We suggest that size-selective mortality--the culling of slower-growing larvae--was the cause of the different error structures of observed and back-calculated lengths at age as well as of the increasing back-calculated lengths at age for older larvae in the matrix of wild gulf menhaden. Predation may have been the cause of size-selective mortality because wild larvae were exposed to predation and laboratory-reared larvae were not. Slopes of regressions of back-calculated length on observed age for columns of the matrices indicate the time trend and intensity of size-selective mortality; in wild gulf menhaden larvae, size-selective mortality began after hatching, reached a plateau at 5-8 d, then declined markedly after 14 d, which suggests that the influence of predation was mainly expressed during this period. Size-selective mortality caused average growth (mean backcalculated or observed length at age) to appear higher for both species, but especially for gulf menhaden, because the smallest larvae of a given age were removed. We adjusted back-calculated growth by removing the effect of size-selective mortality with analysis of covariance and estimated that the observed growth rate was 25% higher than the adjusted rate for wild gulf menhaden and 7% higher for wild king mackerel. RP Grimes, CB (reprint author), NATL MARINE FISHERIES SERV, SE FISHERIES SCI CTR, PANAMA CITY LAB, 3500 DELWOOD BEACH RD, PANAMA CITY, FL 32408 USA. NR 59 TC 12 Z9 12 U1 0 U2 0 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 0002-8487 J9 T AM FISH SOC JI Trans. Am. Fish. Soc. PD SEP PY 1996 VL 125 IS 5 BP 741 EP 752 DI 10.1577/1548-8659(1996)125<0741:IOSMOG>2.3.CO;2 PG 12 WC Fisheries SC Fisheries GA VJ089 UT WOS:A1996VJ08900009 ER PT J AU McLaughlin, WL OHara, KPJ AF McLaughlin, WL OHara, KPJ TI The importance of reference standard and routine absorbed-dose measurements in blood irradiation. SO TRANSFUSION LA English DT Meeting Abstract C1 NIST,GAITHERSBURG,MD 20899. NORDION INT INC,KANATA,ON,CANADA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER ASSOC BLOOD BANKS PI BETHESDA PA 8101 GLENBROOK RD, BETHESDA, MD 20814-2749 SN 0041-1132 J9 TRANSFUSION JI Transfusion PD SEP PY 1996 VL 36 IS 9 SU S BP A61 EP A61 PG 1 WC Hematology SC Hematology GA VK089 UT WOS:A1996VK08900320 ER PT J AU Amadore, L Bolhofer, WC Cruz, RV Feir, RB Freysinger, CA Guill, S Jalal, KF Iglesias, A Jose, A Leatherman, S Lenhart, S Mukherjee, S Smith, JB Wisniewski, J AF Amadore, L Bolhofer, WC Cruz, RV Feir, RB Freysinger, CA Guill, S Jalal, KF Iglesias, A Jose, A Leatherman, S Lenhart, S Mukherjee, S Smith, JB Wisniewski, J TI Climate change vulnerability and adaptation in Asia and the Pacific: Workshop summary SO WATER AIR AND SOIL POLLUTION LA English DT Article; Proceedings Paper CT Regional Workshop on Climate Change Vulnerability and Adaptation in Asia and the Pacific CY JAN 15-19, 1996 CL MANILA, PHILIPPINES SP Philippine Atmospher Geophys & Astron Serv Adm, US Country Studies Program, Asian Dev Bank DE Asia; Pacific island nations; adaptation; agriculture; forest; coastal resources; water resources; sea level rise; national action plans AB The Regional Workshop on Climate Change Vulnerability and Adaptation Assessment in Asia and the Pacific met to present and discuss assessments of vulnerability and adaptation to climate change in agriculture, forests, coastal resources, and water resources. Discussions were held in breakout and plenary sessions about the state of the science for vulnerability and adaptation assessment conclusions that can be drawn about the vulnerability of the region to climate change, and where future research efforts should be directed. The workshop concluded that sea level rise is of greatest concern to island and coastal nations in the region, climate change will have a significant effect on agriculture, water resources are sensitive to changes in average climate conditions and to tropical monsoons and cyclones, and forests could be significantly affected by climate change. The workshop recommended that efforts to improve general circulation models continue and that countries in the region cooperate on the analyses of vulnerability and addressing adaptation measures. The workshop also concluded that results of vulnerability and adaptation assessments should be presented to policy makers and the public and that assessments continue to be undertaken to improve our understanding of the issue. C1 NOAA,NATL WEATHER SERV,WIA,SILVER SPRING,MD 20910. UNIV PHILIPPINES,LOS BANOS,PHILIPPINES. NAMIRA,MANILA,PHILIPPINES. CAMBER CORP,WASHINGTON,DC 20005. US COUNTRY STUDIES PROGRAM,WASHINGTON,DC 20585. ASIAN DEV BANK,ORTIGAS CTR,PASIG CITY,METRO MANILA,PHILIPPINES. INST NACL INVEST AGR,CIFOR,MADRID 28040,SPAIN. UNIV MARYLAND,DEPT GEOG,LAB COASTAL RES,COLLEGE PK,MD 20742. HAGLER BAILLY CONSULTING INC,BOULDER,CO 80306. RP Amadore, L (reprint author), PAGASA,1424 QUEZON AVE,QUEZON 1100,PHILIPPINES. NR 0 TC 13 Z9 13 U1 0 U2 11 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0049-6979 J9 WATER AIR SOIL POLL JI Water Air Soil Pollut. PD SEP PY 1996 VL 92 IS 1-2 BP 1 EP 12 PG 12 WC Environmental Sciences; Meteorology & Atmospheric Sciences; Water Resources SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences; Water Resources GA VM538 UT WOS:A1996VM53800003 ER PT J AU Albers, SC McGinley, JA Birkenheuer, DL Smart, JR AF Albers, SC McGinley, JA Birkenheuer, DL Smart, JR TI The local analysis and prediction system (LAPS): Analyses of clouds, precipitation, and temperature SO WEATHER AND FORECASTING LA English DT Article ID MODEL AB The Local Analysis and Prediction System combines numerous data sources into a set of analyses and forecasts on a 10-km grid with high temporal resolution. To arrive at an analysis of cloud cover, several input analyses are combined with surface aviation observations and pilot reports of cloud layers. These input analyses are a skin temperature analysis (used to solve for cloud layer heights and coverage) derived from Geostationary Operational Environmental Satellite IR 11.24-mu m data, other visible and multispectral imagery, a three-dimensional temperature analysis, and a three-dimensional radar reflectivity analysis derived from full volumetric radar data. Use of a model first guess for clouds is currently being phased in. The goal is to combine the data sources to take advantage of their strengths, thereby automating the synthesis similar to that of a human forecaster. The design of the analysis procedures and output displays focuses on forecaster utility. A number of derived fields are calculated including cloud type, liquid water content, ice content, and icing severity, as well as as precipitation type, concentration, and accumulation. Results from validating the cloud fields against independent data obtained during the Winter Icing and Storms Project are presented. Forecasters can now make use of these analyses in a variety of situations, such as depicting sky cover and radiation characteristics over a region, three-dimensionally delineating visibility and icing conditions for aviation, depicting precipitation type, rain and snow accumulation, etc. C1 COLORADO STATE UNIV,COOPERAT INST RES ATMOSPHERE,FT COLLINS,CO 80523. RP Albers, SC (reprint author), NOAA,FORECAST SYST LAB,R E FS1,325 BROADWAY,BOULDER,CO 80303, USA. RI Birkenheuer, Daniel/E-7378-2015; Albers, Steven/E-7416-2015 NR 19 TC 115 Z9 141 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD SEP PY 1996 VL 11 IS 3 BP 273 EP 287 DI 10.1175/1520-0434(1996)011<0273:TLAAPS>2.0.CO;2 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VE211 UT WOS:A1996VE21100001 ER PT J AU Brooks, HE Doswell, CA AF Brooks, HE Doswell, CA TI A comparison of measures-oriented and distributions-oriented approaches to forecast verification SO WEATHER AND FORECASTING LA English DT Article AB The authors have carried out verification of 590 12-24-h high-temperature forecasts from numerical guidance products and human forecasters for Oklahoma City, Oklahoma, using both a measures-oriented verification scheme and a distributions-oriented scheme. The latter captures the richness associated with the relationship of forecasts and observations, providing insight into strengths and weaknesses of the forecasting systems, and showing areas in which improvement in accuracy can be obtained. The analysis of this single forecast element at one lead time shows the amount of information available from a distributions-oriented verification scheme. In order to obtain a complete picture of the overall state of forecasting, it would be necessary to verify all elements at all lead times. The authors urge the development of such a national verification scheme as soon as possible, since without it, it will be impossible to monitor changes in the quality of forecasts and forecasting systems in the future. RP Brooks, HE (reprint author), NOAA,ENVIRONM RES LABS,NATL SEVERE STORMS LAB,1313 HALLEY CIRCLE,NORMAN,OK 73069, USA. RI Doswell III, Charles/E-7662-2010 NR 9 TC 43 Z9 45 U1 1 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD SEP PY 1996 VL 11 IS 3 BP 288 EP 303 DI 10.1175/1520-0434(1996)011<0288:ACOMOA>2.0.CO;2 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VE211 UT WOS:A1996VE21100002 ER PT J AU Powell, MD Houston, SH Reinhold, TA AF Powell, MD Houston, SH Reinhold, TA TI Hurricane Andrew's landfall in south Florida .1. Standardizing measurements for documentation of surface wind fields SO WEATHER AND FORECASTING LA English DT Article ID BOUNDARY-LAYER; WATER-VAPOR; ROUGHNESS; AIR; SEA; PARAMETERIZATION; MODERATE; INTENSE; DRAG AB Hurricane Andrew's landfall in south Florida left a swath of destruction, including many failed anemometer recording systems. Extreme destruction led to exaggerated claims of the range of wind speeds that caused such damage. The authors accumulated all available data from surface platforms at heights ranging from 2 to 60 m and reconnaissance aircraft at altitudes near 3 km. Several procedures were used to represent the various types of wind measurements in a common framework for exposure, measurement height, and averaging period. This set of procedures allowed documentation of Andrew's winds in a manner understandable to both meteorologists and wind engineers. The procedures are accurate to +/-10% for marine and land observing platforms, and boundary layer model adjustments of flight-level winds to the surface compare to within 20% of the nearest surface measurements. Failure to implement the adjustment procedures may lead to errors of 15%-40%. Quality control of the data is discussed, including treatment of peak wind observations and determination of the radius of maximum winds at the surface. C1 CLEMSON UNIV,DEPT CIVIL ENGN,CLEMSON,SC 29634. RP Powell, MD (reprint author), NOAA,ATLANTIC OCEANOG & METEOROL LAB,HURRICANE RES DIV,4301 RICKENBACKER CAUSEWAY,MIAMI,FL 33149, USA. RI Powell, Mark/I-4963-2013 OI Powell, Mark/0000-0002-4890-8945 NR 57 TC 144 Z9 149 U1 1 U2 8 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD SEP PY 1996 VL 11 IS 3 BP 304 EP 328 DI 10.1175/1520-0434(1996)011<0304:HALISF>2.0.CO;2 PG 25 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VE211 UT WOS:A1996VE21100003 ER PT J AU Powell, MD Houston, SH AF Powell, MD Houston, SH TI Hurricane Andrew's landfall in south Florida .2. Surface wind fields and potential real-time applications SO WEATHER AND FORECASTING LA English DT Article ID TROPICAL CYCLONES; MODEL; SIMULATION; SEASON AB All available wind data associated with Hurricane Andrew's passage were analyzed for periods corresponding to landfall south of Miami and emergence from southwest Florida At landfall in southeast Florida, maximum sustained 1-min surface wind speeds V-M1 reached just over 60 m s(-1) in the northern eyewall over land; by the time Andrew exited the Florida peninsula, the peak value of V-M1 over land decreased to 40-45 m s(-1). Radar reflectivity observations from Tampa and Melbourne could not support an obvious correlation of convective cell development with coastal convergence during landfall on the southeast coast. On the southwest coast, however, convective cell development in the southern eyewall was supported by a coastal convergence maximum. Comparison of the wind swath with two independent Fujita-scale damage maps indicated that peak swath speeds compared well with damage-derived speed equivalents in the worst damaged areas but were higher than equivalents in moderately damaged areas. Comparison of the analysis maximum wind swath with an engineering survey of damaged homes suggests that homes exposed to a wide range of wind directions while subjected to high wind speeds suffered the most damage. Potential real-time applications of wind field products include warning dissemination, emergency management, storm surge and wave forecasting, and wind engineering. Development of damage assessment models for disaster mitigation is addressed from the viewpoint of an electrical utility. RP Powell, MD (reprint author), NOAA,ATLANTIC OCEANOG & METEOROL LAB,HURRICANE RES DIV,4301 RICKENBACKER CSWY,MIAMI,FL 33149, USA. RI Powell, Mark/I-4963-2013 OI Powell, Mark/0000-0002-4890-8945 NR 51 TC 108 Z9 113 U1 3 U2 9 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD SEP PY 1996 VL 11 IS 3 BP 329 EP 349 DI 10.1175/1520-0434(1996)011<0329:HALISF>2.0.CO;2 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VE211 UT WOS:A1996VE21100004 ER PT J AU Slonaker, RL Schwartz, BE Emery, WJ AF Slonaker, RL Schwartz, BE Emery, WJ TI Occurrence of nonsurface superadiabatic lapse rates within RAOB data SO WEATHER AND FORECASTING LA English DT Article ID RAWINSONDE OBSERVATIONS AB As part of creating an atmospheric database for research purposes, 73 497 radiosonde observation (RAOB) soundings from 1983 through 1987 were checked for nonsurface (at least 50 mb above the surface) superadiabatic lapse rates (SLRs). About 60% of the input profiles contain a nonsurface SLR, most of which are subtle. Some of the superadiabatic reports are extreme, indicating probable RAOB error. These erroneous upper-air data are capable of corrupting derived meteorological parameters and analyses. A check for nonsurface SLRs allows these suspect data to be flagged for deletion or correction. The occurrence of superadiabatic reports is somewhat correlated with season and geographic location. However, all meteorological conditions are prone to these reports of nonsurface SLRs. A quality control criterion is developed to check for nonsurface SLRs using potential temperature, which is not overly sensitive in thin layers (as opposed to lapse rate). During RAOB ascent, any nonsurface report of a potential temperature decrease of more than 1 K is flagged for superadiabatic quality control failure. This threshold rejects the worst 4.3% of input upper-air profiles, allowing the vast majority of minor occurrences to pass. The meteorological and climatological communities should be aware of the occurrence of nonsurface SLRs within RAOB data. C1 UNIV COLORADO,COLORADO CTR ASTRODYNAM RES,BOULDER,CO 80309. NOAA,ENVIRONM RES LAB,FORECAST SYST LAB,BOULDER,CO 80303. OI Emery, William/0000-0002-7598-9082 NR 12 TC 7 Z9 7 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD SEP PY 1996 VL 11 IS 3 BP 350 EP 359 DI 10.1175/1520-0434(1996)011<0350:OONSLR>2.0.CO;2 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VE211 UT WOS:A1996VE21100005 ER PT J AU Schwartz, B AF Schwartz, B TI The quantitative use of PIREPs in developing aviation weather guidance products SO WEATHER AND FORECASTING LA English DT Article AB An evaluation of the utility of pilot reports (PIREPs) of weather for aviation forecasting product development is presented. Although PIREPs were never intended for quantitative use, this limitation has not prevented developers of improved aviation weather guidance products (such as turbulence or icing forecasting schemes) from using these data. In this paper, an analysis of turbulence reports over the continental United States and Alaska is employed to show that the reports contained within the PIREPs database are inadequate for defining the actual phenomenology of aviation weather hazards. The results suggest that conclusions regarding the frequency of occurrence and intensity of reported aviation weather phenomena contained within PIREPs should not be based on their reported distribution alone because of the effects of operational constraints and various outside influences. The results also suggest that these data are inadequate for developing, calibrating, and validating aviation weather forecasting guidance products. The procedures and regulations for acquiring PIREPs are included in this report, and a discussion is presented suggesting that improvement to the current voice PIREP reporting system might have a wide range of benefits for both the operational and research aviation meteorological communities. RP Schwartz, B (reprint author), NOAA,ENVIRONM RES LAB,FORECAST SYST LAB,325 BROADWAY,BOULDER,CO 80303, USA. NR 13 TC 26 Z9 26 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD SEP PY 1996 VL 11 IS 3 BP 372 EP 384 DI 10.1175/1520-0434(1996)011<0372:TQUOPI>2.0.CO;2 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VE211 UT WOS:A1996VE21100007 ER PT J AU Kelsch, M Wharton, L AF Kelsch, M Wharton, L TI Comparing PIREPs with NAWAU turbulence and icing forecasts: Issues and results SO WEATHER AND FORECASTING LA English DT Article AB Pilot reports of aircraft turbulence and icing were compared with forecasts of those phenomena from the National Aviation Weather Advisory Unit for a 45-day period in the winter of 1992. An observation-driven approach was used because it is considered more appropriate for accomodating the subjective reporting that is characteristic of the observational dataset. A number of comparisons were done for subsets of the data based on the magnitude of the reported event, aircraft altitude, and type of forecast. Positive observations of events compared with forecasts more favorably for the icing data than for the turbulence data. Observations of nonevents compared with forecasts more favorably for the turbulence data than for the icing data. Positive observations of both icing and turbulence compared with forecasts more favorably below 18 000 ft than above 18 000 ft. Null reports for icing appear to be more representative of ''no icing'' than the zero-icing reports. C1 COLORADO STATE UNIV,COOPERAT INST RES ATMOSPHERE,FT COLLINS,CO 80523. RP Kelsch, M (reprint author), NOAA,FORECAST SYST LAB,R E FS1,325 BROADWAY,BOULDER,CO 80303, USA. NR 6 TC 11 Z9 11 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD SEP PY 1996 VL 11 IS 3 BP 385 EP 390 DI 10.1175/1520-0434(1996)011<0385:CPWNTA>2.0.CO;2 PG 6 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VE211 UT WOS:A1996VE21100008 ER PT J AU Rogers, E Black, TL Deaven, DG DiMego, GJ Zhao, QY Baldwin, M Junker, NW Lin, Y AF Rogers, E Black, TL Deaven, DG DiMego, GJ Zhao, QY Baldwin, M Junker, NW Lin, Y TI Changes to the operational ''early'' eta analysis/forecast system at the National Centers for Environmental Prediction SO WEATHER AND FORECASTING LA English DT Article ID CONVECTIVE ADJUSTMENT SCHEME; REGIONAL-ANALYSIS SYSTEM; STEP-MOUNTAIN ETA; FORECAST SYSTEM; MODEL; PARAMETERIZATION; COORDINATE; WATER; VERIFICATION; CONDENSATION AB This note describes changes that have been made to the National Centers for Environmental Prediction (NCEP) operational ''early'' eta model. The changes are 1) an decrease in horizontal grid spacing from 80 to 48 km, 2) incorporation of a cloud prediction scheme, 3) replacement of the original static analysis system with a 12-h intermittent data assimilation system using the eta model, and 4) the use of satellite-sensed total column water data in the eta optimum interpolation analysis. When tested separately, each of the four changes improved model performance. A quantitative and subjective evaluation of the full upgrade package during March and April 1995 indicated that the 48-km eta model was more skillful than the operational 80-km model in predicting the intensity and movement of large-scale weather systems. In addition, the 48-km era model was more skillful in predicting severe mesoscale precipitation events than either the 80-km eta model, the nested grid model, or the NCEP global spectral model during the March-April 1995 period. The implementation of this new version of the operational early era system was performed in October 1995. C1 GEN SCI CORP,LAUREL,MD. NATL CTR ENVIRONM PREDICT,HYDROMETEOROL PREDICT CTR,WASHINGTON,DC. UNIV CORP ATMOSPHER RES,BOULDER,CO. RP Rogers, E (reprint author), NOAA,NATL WEATHER SERV,NATL CTR ENVIRONM PREDICT,ENVIRONM MODELING CTR,WINP22,WWB,ROOM 204,WASHINGTON,DC 20233, USA. NR 40 TC 156 Z9 159 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD SEP PY 1996 VL 11 IS 3 BP 391 EP 413 DI 10.1175/1520-0434(1996)011<0391:CTTOEA>2.0.CO;2 PG 23 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VE211 UT WOS:A1996VE21100009 ER PT J AU Moore, JL Gorshkova, II Brown, JW McKenney, KH Schwarz, FP AF Moore, JL Gorshkova, II Brown, JW McKenney, KH Schwarz, FP TI Effect of cAMP binding site mutations on the interaction of cAMP receptor protein with cyclic nucleoside monophosphate ligands and DNA SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID GENE ACTIVATOR PROTEIN; ENTHALPY-ENTROPY COMPENSATION; ESCHERICHIA-COLI; TRANSCRIPTION ACTIVATION; LAC PROMOTER; AMP; CAP; COMPLEX; MUTANTS; RECOGNITION AB Although cAMP binding to wild type cAMP receptor protein (CRP) induces specific DNA binding and activates transcription, cyclic nucleoside monophosphate (cNMP) binding to the CRP mutant Ser(128) --> Ala does not, whereas the double CRP mutant Thr(127) --> Leu/ Ser(128) --> Ala activates transcription even in the absence of cNMP. Isothermal titration calorimetry measurements on the cNMP binding reactions to the S128A and T127L/S128A mutants show that the reactions are mainly entropically driven as is cAMP binding to CRP. In contrast to cAMP binding to CRP, the binding reactions are noncooperative and exothermic with binding enthalpies (Delta H-b) ranging from -23.4 +/- 0.9 kJ mol(-1) for cAMP binding to S128A at 39 degrees C to -4.1 +/- 0.6 kJ mol(-1) for cAMP binding to T127L/S128A at 24 degrees C and exhibit enthalpy-entropy compensation. To account for the inactivity of the S128A mutant, in vitro and in vivo DNA binding experiments were performed on the cAMP-ligated S128A mutant. The cAMP-ligated S128A mutant binds to the consensus DNA binding site with approximately the same affinity as that of cAMP-ligated CRP but forms a different type of complex, which may account for loss of transcriptional activity by the mutant, Energy minimization computations on the cAMP-ligated S128A mutant show that amino acid conformational differences between S128A and CRP occur at Ser(179), Glu(181), and Thr(182) in the center of the DNA binding site, implying that these conformational changes may account for the difference in DNA binding. C1 NIST,CTR ADV RES BIOTECHNOL,ROCKVILLE,MD 20850. RUSSIAN ACAD SCI,INST BIOORGAN CHEM,NOVOSIBIRSK 630090,RUSSIA. NR 43 TC 18 Z9 18 U1 0 U2 1 PU AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 SN 0021-9258 J9 J BIOL CHEM JI J. Biol. Chem. PD AUG 30 PY 1996 VL 271 IS 35 BP 21273 EP 21278 PG 6 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA VE477 UT WOS:A1996VE47700049 PM 8702903 ER PT J AU Keller, RR Phelps, JM Read, DT AF Keller, RR Phelps, JM Read, DT TI Tensile and fracture behavior of free-standing copper films SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE tensile behaviour; fracture; copper films ID THIN-FILMS; DISLOCATION-STRUCTURES; NANOCRYSTALLINE CU; DUCTILE FRACTURE; DEFORMATION; STRENGTH; METALS; CRACKS; PD AB We have studied tensile deformation and crack growth behavior of free-standing, electron beam evaporated copper films suspended over windows etched in a silicon substrate. In-situ straining experiments were performed on these films using a transmission electron microscope. External tests were conducted on a piezoelectric-driven microtensile system. Macroscopically, these copper films exhibited very low ductility (<1%). Dislocation activity was limited in regions far From propagating cracks. We discuss this in terms of how limited film thickness and fine grain size restrict dislocation glide distances and source operation during uniform loading. Near stable growing cracks, we observed considerable local plasticity. We saw evidence of slip activity both within grain interiors and in grain boundaries near such cracks. Although some dislocations moved very fast, others showed rates much lower than those typically measured for bulk copper. Fracture was both intergranular and transgranular, and occurred by linking of microcracks. Microcracks formed within one grain diameter or so of the main crack, usually within a grain boundary. Linking then look place by the easiest available path. A thickness-limited fracture toughness relation adequately describes the observed behavior. RP Keller, RR (reprint author), NATL INST STAND & TECHNOL,DIV MAT RELIABIL,325 BROADWAY,BOULDER,CO 80303, USA. RI Keller, Robert/I-9014-2012 NR 31 TC 61 Z9 66 U1 4 U2 13 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE 1 PA PO BOX 564, 1001 LAUSANNE 1, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD AUG 30 PY 1996 VL 214 IS 1-2 BP 42 EP 52 DI 10.1016/0921-5093(96)10253-7 PG 11 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA VH129 UT WOS:A1996VH12900005 ER PT J AU Barone, SB Turnipseed, AA Ravishankara, AR AF Barone, SB Turnipseed, AA Ravishankara, AR TI Reaction of OH with dimethyl sulfide (DMS) .1. Equilibrium constant for OH+DMS reaction and the kinetics of the OH center dot DMS+O-2 reaction SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID RADICALS; SULFUR; MECHANISM; STATE; DISULFIDE; CH3SCH3; CS2 AB The formation of a weakly bound adduct in the reaction of OH with DMS-d(6) was observed between 217 and 240 K using the technique of pulsed laser photolysis/pulsed laser-induced fluorescence. The equilibrium constant for this process, OH + DMS-d(6) <----> OH . DMS-d(6), was measured as a function of temperature. The bond strength of this adduct was determined to be 10.7 +/- 2.5 kcal mol(-1). The weakly bound adduct was observed to react rapidly with O-2. The rate constant for the reaction OH . DMS-d(6) + O-2 --> products was determined to be (1.00 +/- 0.33) x 10(-12) cm(3) molecules(-1) s(-1), independent of pressure and temperature. The atmospheric implications of the formation of this adduct and its reaction with O-2 to the mechanism of DMS oxidation in the atmosphere are discussed. C1 NOAA,ERL,AERON LAB,BOULDER,CO 80303. UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. UNIV COLORADO,COOPERAT INST ENVIRONM SCI,BOULDER,CO 80309. RI Ravishankara, Akkihebbal/A-2914-2011 NR 25 TC 78 Z9 78 U1 0 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD AUG 29 PY 1996 VL 100 IS 35 BP 14694 EP 14702 DI 10.1021/jp960866k PG 9 WC Chemistry, Physical SC Chemistry GA VE373 UT WOS:A1996VE37300022 ER PT J AU Turnipseed, AA Barone, SB Ravishankara, AR AF Turnipseed, AA Barone, SB Ravishankara, AR TI Reaction of OH with dimethyl sulfide .2. Products and mechanisms SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID ATMOSPHERIC CHEMISTRY; QUANTUM YIELDS; RADICALS; KINETICS; DISULFIDE; PHOTOOXIDATION; OXIDATION; CH3OOH; CH3S; METHANETHIOL AB The technique of pulsed laser photolysis/pulsed laser-induced fluorescence was used to determine products of the following reactions: OH + CH3SCH3 --> products (1) and CH3S(OH)CH3 + O-2 --> products (5). The non-adduct-forming channel of reaction 1 was observed to proceed via hydrogen abstraction (branching ratio, Phi(abs) = 0.84 +/- 0.26) at 298 K. Direct formation of CH3S from reaction 1 was not observed (Phi(CH3S) < 0.04) A small channel for producing CH3 and CH3SOH in the non-adduct-forming route could not be ruled out. HO2 was found to be produced from reaction 5 with a yield of 0.50 +/- 0.15 at 234 and 258 K. An upper limit for the production of OH from reaction 5 was determined to be Phi(OH) < 0.05. The atmospheric implications of the results from this and the accompanying paper are discussed. C1 NOAA,ENVIRONM RES LAB,AERON LAB,BOULDER,CO 80303. UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. UNIV COLORADO,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. RI Ravishankara, Akkihebbal/A-2914-2011 NR 40 TC 88 Z9 88 U1 2 U2 11 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD AUG 29 PY 1996 VL 100 IS 35 BP 14703 EP 14713 DI 10.1021/jp960867c PG 11 WC Chemistry, Physical SC Chemistry GA VE373 UT WOS:A1996VE37300023 ER PT J AU Xie, PP Rudolf, B Schneider, U Arkin, PA AF Xie, PP Rudolf, B Schneider, U Arkin, PA TI Gauge-based monthly analysis of global land precipitation from 1971 to 1994 SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID FLUCTUATIONS; 30-DEGREES-S; CLIMATOLOGY; RAINFALL; AVERAGES; NETWORKS; AREAS; OCEAN; MODEL AB Monthly gridded fields of global land precipitation have been constructed on 2.5 degrees latitude/longitude grids for a 24-year period from 1971 to 1994 by interpolating gauge observations at over 6000 stations contained in the Global Historical Climatology Network of the Carbon Dioxide Information Center of U.S. Department of Energy and the Climate Anomaly Monitoring System of the Climate Prediction Center of National Oceanic and Atmospheric Administration. Sensitivity tests indicated that this gauge-based analysis has relatively high quality in general and that its quantitative accuracy increases with the gauge network density. Significant value-dependent bias and random error, however, exist in the analysis over grid areas with few gauges. The mean distribution and annual cycle of the 24-year gauge-based analysis showed close agreement with those of several published long-term means, and the inter-annual variations in precipitation associated with the El Nino-Southern Oscillation phenomenon were evident. Despite the ability of this gauge-based analysis to describe large-scale precipitation over global land areas, further efforts are needed to improve the interpolation algorithm, to increase gauge network density, and to combine the gauge analysis with other information sources based on satellite observations, especially over grid areas with poor gauge coverage. C1 DEUTSCH WETTERDIENST, GLOBAL PRECIPITAT CLIMATOL CTR, D-63004 OFFENBACH, GERMANY. RP Xie, PP (reprint author), NOAA, NATL WEATHER SERV, NATL CTR ENVIRONM PREDICT, WASHINGTON, DC 20233 USA. RI Arkin, Phillip/F-5808-2010 NR 37 TC 69 Z9 71 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD AUG 27 PY 1996 VL 101 IS D14 BP 19023 EP 19034 DI 10.1029/96JD01553 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VE258 UT WOS:A1996VE25800005 ER PT J AU Rosenlof, KH AF Rosenlof, KH TI Summer hemisphere differences in temperature and transport in the lower stratosphere SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID GENERALIZED ELIASSEN-PALM; DOWNWARD CONTROL; MERIDIONAL CIRCULATION; TROPOSPHERE; MODEL; VARIABILITY; SIMULATION; EXCHANGE; WAVES AB Lower stratospheric temperatures during southern hemisphere summer are found to be warmer than at the same latitude poleward of the equator during northern hemisphere summer. Coincident with such warmer temperatures is a stronger residual circulation as calculated from radiative heating rates computed using as input observations from the Upper Atmospheric Research Satellite (UARS). Such a summertime asymmetry in extratropical downwelling in the lower stratosphere does not appear in the residual circulation calculated via the downward control technique based on National Meteorological Center (NMC) analyses. Computing the residual circulation With the downward control technique using Eliassen-Palm flux divergences based on assimilated winds and temperatures does yield the above noted summertime hemispheric asymmetry in downward extratropical mass transport, although not as pronounced as with the radiative calculation. It is proposed that smaller-scale zonal forces due to gravity waves, absent in the NMC downward control calculation, may be important for driving the southern hemisphere summer circulation in the lower stratosphere. C1 UNIV COLORADO, NOAA, COOPERAT INST RES ENVIRONM SCI, BOULDER, CO 80309 USA. RI Rosenlof, Karen/B-5652-2008 OI Rosenlof, Karen/0000-0002-0903-8270 NR 25 TC 21 Z9 21 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD AUG 27 PY 1996 VL 101 IS D14 BP 19129 EP 19136 DI 10.1029/96JD01542 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VE258 UT WOS:A1996VE25800013 ER PT J AU Traiber, AJS Turchi, PEA Waterstrat, RM Allen, SM AF Traiber, AJS Turchi, PEA Waterstrat, RM Allen, SM TI Electronic structure and phase equilibria in ternary substitutional alloys SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article ID TIGHT-BINDING PARAMETERS; GROUND-STATE STRUCTURES; TRANSITION-METALS; BINARY-ALLOYS; SYSTEMS; STABILITY; DIAGRAMS; SILICON; ENERGY; MODEL AB A reliable and consistent scheme for studying phase equilibria in ternary substitutional alloys based on the tight-binding approximation is presented. With the electronic parameters obtained from linear muffin-tin orbital calculations, we show that the computed densities of states and band structures compare well with those obtained from more accurate ab initio calculations. Disordered alloys are studied within the tight-binding coherent-potential approximation formalism extended to multi-component alloys. The energetics of ordered systems is obtained through effective-pair interactions computed with the general perturbation method. Finally, partially ordered alloys are studied with a novel simplification of the molecular coherent-potential approximation combined with the general perturbation method. The formalism is applied to the study of bcc-based ternary Zr-Ru-Pd alloys which are promising candidates for medical implant device applications. Using the energetics obtained with the aforementioned scheme, we apply the cluster-variation method to study phase equilibria for particular pseudo-binary alloys, and show that the results are consistent with the observed behaviour of the electronic specific heat coefficient with composition for the Zr-0.5(Ru, Pd)(0.5) system. C1 LAWRENCE LIVERMORE NATL LAB,DEPT CHEM & MAT SCI,LIVERMORE,CA 94551. NIST,DIV MET,GAITHERSBURG,MD 20899. RP Traiber, AJS (reprint author), MIT,DEPT MAT SCI & ENGN,CAMBRIDGE,MA 02139, USA. NR 65 TC 10 Z9 10 U1 1 U2 6 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0953-8984 J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD AUG 26 PY 1996 VL 8 IS 35 BP 6357 EP 6379 DI 10.1088/0953-8984/8/35/006 PG 23 WC Physics, Condensed Matter SC Physics GA VE807 UT WOS:A1996VE80700006 ER PT J AU Edwards, M Ruprecht, PA Burnett, K Dodd, RJ Clark, CW AF Edwards, M Ruprecht, PA Burnett, K Dodd, RJ Clark, CW TI Collective excitations of atomic Bose-Einstein condensates SO PHYSICAL REVIEW LETTERS LA English DT Article ID GAS AB We apply linear-response analysis of the Gross-Pitaevskii equation to obtain the excitation frequencies of a Bose-Einstein condensate confined in a time-averaged orbiting potential trap. Our calculated values are in excellent agreement with those observed in a recent experiment. C1 UNIV OXFORD,DEPT PHYS,CLARENDON LAB,OXFORD OX1 3PU,ENGLAND. NIST,DIV ELECTRON & OPT PHYS,TECHNOL ADM,US DEPT COMMERCE,GAITHERSBURG,MD 20899. UNIV MARYLAND,INST PHYS SCI & TECHNOL,COLLEGE PK,MD 20742. RP Edwards, M (reprint author), GEORGIA SO COLL,DEPT PHYS,STATESBORO,GA 30460, USA. RI Clark, Charles/A-8594-2009; OI Clark, Charles/0000-0001-8724-9885; Edwards, Mark/0000-0002-3149-2402 NR 22 TC 304 Z9 304 U1 2 U2 14 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD AUG 26 PY 1996 VL 77 IS 9 BP 1671 EP 1674 DI 10.1103/PhysRevLett.77.1671 PG 4 WC Physics, Multidisciplinary SC Physics GA VD430 UT WOS:A1996VD43000003 ER PT J AU Hastie, JW Schenck, PK Paul, AJ Bonnell, DW AF Hastie, JW Schenck, PK Paul, AJ Bonnell, DW TI In-situ diagnostics for pulsed laser deposition of ceramic films SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 25 PY 1996 VL 212 BP 7 EP MTLS PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA VB009 UT WOS:A1996VB00901658 ER PT J AU Pellegrino, J ChapmanWilbert, M Zydney, A Lohnes, T AF Pellegrino, J ChapmanWilbert, M Zydney, A Lohnes, T TI Electrokinetic characterization of surfactant modification and fouling on RO/NF membranes. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,BOULDER,CO 80303. US BUR RECLAMAT,DENVER,CO 80225. UNIV COLORADO,DEPT CHE,BOULDER,CO 80309. UNIV DELAWARE,DEPT CHE,NEWARK,DE. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 25 PY 1996 VL 212 BP 10 EP ENVR PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA VA915 UT WOS:A1996VA91501637 ER PT J AU Karim, A Douglas, JF Han, CC AF Karim, A Douglas, JF Han, CC TI Frustrated coalescence in reactive blends. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST,DIV POLYMERS,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 25 PY 1996 VL 212 BP 35 EP PMSE PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA VB009 UT WOS:A1996VB00901314 ER PT J AU Guttman, CM Blair, WR AF Guttman, CM Blair, WR TI Absorption studies of archival boxboards and model handsheets exposed to ppm and ppb concentrations of nitrogen dioxide SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST,DIV POLYMERS,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 25 PY 1996 VL 212 BP 41 EP POLY PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA VB009 UT WOS:A1996VB00900894 ER PT J AU Thomas, JB Sharpless, KE Kline, MC AF Thomas, JB Sharpless, KE Kline, MC TI Stability of fat-soluble vitamins and carotenoids in human serum. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 25 PY 1996 VL 212 BP 52 EP ANYL PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA VA915 UT WOS:A1996VA91500298 ER PT J AU Eglinton, TI Pearson, A McNichol, AP Currie, LA Benner, BA Wise, SA AF Eglinton, TI Pearson, A McNichol, AP Currie, LA Benner, BA Wise, SA TI Compound specific radiocarbon analysis as a tool to quantitatively apportion modern and fossil sources of polycyclic aromatic hydrocarbons in environmental matrices. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 WOODS HOLE OCEANOG INST,WOODS HOLE,MA 02543. NIST,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 25 PY 1996 VL 212 BP 65 EP ENVR PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA VA915 UT WOS:A1996VA91501692 ER PT J AU Johnson, RD Hudgens, JW AF Johnson, RD Hudgens, JW TI Low lying vibrational states of hydroxymethyl (CH2OH) radicals and cations derived from observations of electronic spectra and from ab initio calculations. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,CHEM & PHYS PROPERT DIV,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 25 PY 1996 VL 212 BP 82 EP COMP PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA VA915 UT WOS:A1996VA91501468 ER PT J AU Bell, CM Sander, LC Fetzer, JC Wise, SA AF Bell, CM Sander, LC Fetzer, JC Wise, SA TI Long-chain alkyl bonded stationary phases for the separation of carotenoids by HPLC SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST,CHEM SCI & TECHNOL LAB,GAITHERSBURG,MD 20899. CHEVRON RES & TECHNOL CO,RICHMOND,CA 94802. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 25 PY 1996 VL 212 BP 91 EP ANYL PN 1 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA VA915 UT WOS:A1996VA91500336 ER PT J AU Jackson, CL McKenna, GB AF Jackson, CL McKenna, GB TI Vitrification and crystallization of organic liquids confined to nanoscale pores SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. RI McKenna, Gregory/O-1134-2013 OI McKenna, Gregory/0000-0002-5676-9930 NR 0 TC 0 Z9 0 U1 2 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 25 PY 1996 VL 212 BP 136 EP PHYS PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA VB009 UT WOS:A1996VB00900639 ER PT J AU OConnor, TP Daskalakis, KD AF OConnor, TP Daskalakis, KD TI Chemical concentrations as markers of human activity SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NOAA,NATL STATUS & TRENDS PROGRAM,SILVER SPRING,MD 20910. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 25 PY 1996 VL 212 BP 146 EP ENVR PN 1 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA VA915 UT WOS:A1996VA91501773 ER PT J AU Roitberg, A Elber, R Gerber, B Rainer, M AF Roitberg, A Elber, R Gerber, B Rainer, M TI Role of multiple minima in protein vibrational spectroscopy. Anharmonic eigenfunctions for different conformers SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899. NORTHWESTERN UNIV,DEPT CHEM,EVANSTON,IL. FRITZ HABER CTR MOL DYNAM,JERUSALEM,ISRAEL. NR 1 TC 0 Z9 0 U1 1 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 25 PY 1996 VL 212 BP 172 EP PHYS PN 2 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA VB009 UT WOS:A1996VB00900675 ER PT J AU Gilson, MK AF Gilson, MK TI Validation in models for the binding of protons and small molecules by proteins. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 CTR ADV RES BIOTECHNOL,ROCKVILLE,MD 20850. NIST,ROCKVILLE,MD 20850. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 25 PY 1996 VL 212 BP 218 EP COMP PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA VA915 UT WOS:A1996VA91501603 ER PT J AU Buntin, SA AF Buntin, SA TI Hyperthermal H atom interactions with D/Si(100) SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,SURFACE & MICROANAL SCI DIV,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 25 PY 1996 VL 212 BP 244 EP PHYS PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA VB009 UT WOS:A1996VB00900745 ER PT J AU Levicky, R Koneripalli, N Tirrell, M Satija, SK Gallagher, PD Ankner, J Kulasekere, R Kaiser, H AF Levicky, R Koneripalli, N Tirrell, M Satija, SK Gallagher, PD Ankner, J Kulasekere, R Kaiser, H TI Morphological changes in block copolymer thin films in contact with selective solvent SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 UNIV MINNESOTA,DEPT CHEM ENGN & MAT SCI,MINNEAPOLIS,MN 55455. NIST,DIV REACTOR RADIAT,GAITHERSBURG,MD 20899. UNIV MISSOURI,RES REACTOR CTR,COLUMBIA,MO 65211. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 25 PY 1996 VL 212 BP 254 EP PMSE PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA VB009 UT WOS:A1996VB00901532 ER PT J AU Roitberg, A AF Roitberg, A TI A molecular dynamics study of the stability of a proposed NMR structure of putidaredoxin. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,DIV BIOTECHNOL,GAITHERSBURG,MD 20899. NR 1 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 25 PY 1996 VL 212 BP 274 EP PHYS PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA VB009 UT WOS:A1996VB00900775 ER PT J AU Ratner, M Roitberg, A Gerber, P Elber, R AF Ratner, M Roitberg, A Gerber, P Elber, R TI Vibrational properties of proteins: A wave function for BPTI. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NATL INST STAND & TECHNOL,DIV BIOTECHNOL,GAITHERSBURG,MD 20899. NORTHWESTERN UNIV,DEPT CHEM,EVANSTON,IL 60203. HEBREW UNIV JERUSALEM,FRITZ HABER INST,IL-91905 JERUSALEM,ISRAEL. HEBREW UNIV JERUSALEM,DEPT PHYS CHEM,IL-91904 JERUSALEM,ISRAEL. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 25 PY 1996 VL 212 BP 320 EP PHYS PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA VB009 UT WOS:A1996VB00900821 ER PT J AU Karim, A Ermi, B Douglas, JF Amis, EJ AF Karim, A Ermi, B Douglas, JF Amis, EJ TI AFM of phase separated polymer blend thin films SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST,DIV POLYMERS,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 25 PY 1996 VL 212 BP 321 EP POLY PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA VB009 UT WOS:A1996VB00901170 ER PT J AU Slomkowski, S Miksa, B Trznadel, M Kowalczyk, D Wang, FW AF Slomkowski, S Miksa, B Trznadel, M Kowalczyk, D Wang, FW TI Synthesis, morphology, and properties of latex monolayers at the quartz-liquid interface. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 CTR MOL & MACROMOL STUDIES,PL-90363 LODZ,POLAND. NIST,DIV POLYMER,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 25 PY 1996 VL 212 BP 333 EP POLY PN 2 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA VB009 UT WOS:A1996VB00901182 ER PT J AU Mountain, RD AF Mountain, RD TI Evidence for a growing length in supercooled liquids SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 25 PY 1996 VL 212 BP 338 EP PHYS PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA VB009 UT WOS:A1996VB00900836 ER PT J AU Butler, KM Baum, HR Kashiwagi, T AF Butler, KM Baum, HR Kashiwagi, T TI Three-dimensional numerical model of intumescent polymers. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 NIST,GAITHERSBURG,MD 20899. NR 0 TC 0 Z9 0 U1 1 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 25 PY 1996 VL 212 BP 383 EP POLY PN 2 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA VB009 UT WOS:A1996VB00901232 ER PT J AU Sampson, DA Cooter, EJ Dougherty, PM Allen, HL AF Sampson, DA Cooter, EJ Dougherty, PM Allen, HL TI Comparison of the UKMO and GFDL GCM climate projections in NPP simulations for southern loblolly pine stands SO CLIMATE RESEARCH LA English DT Article DE loblolly pine; GCM; UKMO; GFDL; climate change ID ELEVATED CARBON-DIOXIDE; CO2 CONCENTRATIONS; SLASH PINE; LEAF-AREA; GROWTH; WATER; MODEL; RESPONSES; RADIATA; FORESTS AB We used the process model BIOMASS version 13.0 to simulate contemporary net primary production (NPP) and NPP response to climate projections for a doubling of atmospheric CO2 concentration from 2 general circulation models (GCMs) that vary in their CO2 sensitivity: the less sensitive GFDL and the more sensitive UKMO. Increased GCM sensitivity to CO2 is reflected in increased predictions in the magnitude, variation, and range of the climate variables. Simulations used a 40 yr historical climate record, and 2 stand and site conditions to standardize the total NPP response estimates for eighteen 1x1 degrees grid cells across the southern United States, Contemporary NPP and NPP response estimates from the 18 cells were smoothed using a cell search algorithm to obtain an NPP response index matrix for the entire loblolly pine (Pinus taeda) forest-type. We conducted a sensitivity analysis of the environmental variables projected to change in a 2xCO(2) environment to help interpret simulation output. Contemporary NPP varied from 2.5 to 8.5 Mg C ha(-1) yr(-1) over the range of loblolly pine, High leaf area index (LAI) simulations had 1.5 to 2 times the productivity of low LAI simulations, but the regional patterns were similar; NPP was correlated with regional differences in precipitation and temperature. The NPP response to future climate and atmospheric changes depended on the GCM used, and on the stand and site condition assumed. Inter-annual estimates for the 18 cell simulations resulted in a +22 to +84% NPP response for the GFDL climate projections and a -30 to +94% NPP response for the UKMO climate projections. The 40-year average NPP response for the smoothed data ranged from +43 to +65% and -1 to +94% for the GFDL and the UKMO climate projections, respectively. Consequently, the magnitude and range of the 40-year average NPP response to the climate projections was directly correlated with the GCM CO2 sensitivity. Although increased CO2 sensitivity resulted in broader extremes in the predicted temperature response, precipitation response for the 2 models was similar. The NPP response was also correlated with the patterns in predicted climate change, with regional differences coupled to local climatic conditions. Climate projections from both models produced similar NPP responses when predicted temperatures and precipitation regimes were similar. Elevated ambient CO2 had a greater effect on NPP response than temperature or precipitation in the sensitivity comparisons. Simulations indicate that a CO2 fertilizer effect, assuming no CO2 acclimation, more than compensates for declines in productivity over most of the loblolly pine forest-type associated with projected decreased precipitation and/or projected low to moderate increases in temperature and, therefore, increased maintenance respiration costs. C1 NOAA,AIR RESOURCES LAB,RES TRIANGLE PK,NC 27711. WESTVACO CORP,FOREST SCI LAB,SUMMERVILLE,SC 29484. RP Sampson, DA (reprint author), N CAROLINA STATE UNIV,DEPT FORESTRY,BOX 8008,RALEIGH,NC 27695, USA. NR 54 TC 8 Z9 8 U1 0 U2 4 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0936-577X J9 CLIMATE RES JI Clim. Res. PD AUG 22 PY 1996 VL 7 IS 1 BP 55 EP 69 DI 10.3354/cr007055 PG 15 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA VK432 UT WOS:A1996VK43200006 ER PT J AU Tobin, DC Strow, LL Lafferty, WJ Olson, WB AF Tobin, DC Strow, LL Lafferty, WJ Olson, WB TI Experimental investigation of the self- and N-2-broadened continuum within the nu(2) band of water vapor SO APPLIED OPTICS LA English DT Article DE infrared absorption; water vapor; continuum; spectral line shape; Fourier transform spectrometer ID LINE-SHAPE THEORY; ROTATIONAL BANDS; ABSORPTION; SOUNDER; REGION; SYSTEM; DESIGN; CELL AB We present an experimental study of the self- and N-2-broadened H2O continuum in microwindows within the nu(2) fundamental centered at similar to 1600 cm(-1). The continuum is derived from transmission spectra recorded at room temperature with a BOMEM Fourier transform spectrometer at a resolution of similar to 0.040 cm(-1). Although we find general agreement with previous studies, our results suggest that there is significant near-wing super-lorentzian behavior that produces a highly wave-number-dependent structure in the continuum as it is currently defined. (C) 1996 Optical Society of America C1 NIST,DIV MOL PHYS,GAITHERSBURG,MD 20899. RP Tobin, DC (reprint author), UNIV MARYLAND,DEPT PHYS,CATONSVILLE,MD 21228, USA. NR 31 TC 50 Z9 54 U1 0 U2 2 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD AUG 20 PY 1996 VL 35 IS 24 BP 4724 EP 4734 DI 10.1364/AO.35.004724 PG 11 WC Optics SC Optics GA VC320 UT WOS:A1996VC32000005 PM 21102892 ER PT J AU Wikfors, GH Patterson, GW Ghosh, P Lewin, RA Smith, BC Alix, JH AF Wikfors, GH Patterson, GW Ghosh, P Lewin, RA Smith, BC Alix, JH TI Growth of post-set oysters, Crassostrea virginica, on high-lipid strains of algal flagellates Tetraselmis spp. SO AQUACULTURE LA English DT Article DE essential fatty acids; molluscan aquaculture; nutrition; sterols ID GMELIN AB Nine microalgal strains from the prasinophyte genus Tetraselmis that were chosen for high total lipid content, and one marine strain of the chlorophyte Chlamydomonas, were compared with Isochrysis sp., strain T-ISO, as diets for oyster spat in a controlled laboratory feeding experiment. Five of these high-lipid Tetraselmis strains supported significantly faster oyster growth than an equivalent ration of T-ISO. Doubling times for oyster weight, volume, and shell height were in the range of 1.5-3 weeks on single daily feedings of the best diets, Tetraselmis strains yielding the most rapid oyster growth contained higher contents of the essential fatty acid 20:5n-3 and of the sterols 24-methylcholesterol and/or 24-methylenecholesterol. These data are consistent with our earlier findings that these compounds appear to be deficient in most phytoplankton for optimal growth of Crassostrea virginica spat. C1 UNIV MARYLAND,DEPT BOT,COLLEGE PK,MD 20742. UNIV CALIF SAN DIEGO,SCRIPPS INST OCEANOG,LA JOLLA,CA 92093. RP Wikfors, GH (reprint author), NOAA,NATL MARINE FISHERIES SERV,NE FISHERIES SCI CTR,MILFORD,CT 06460, USA. NR 17 TC 45 Z9 46 U1 0 U2 16 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0044-8486 J9 AQUACULTURE JI Aquaculture PD AUG 20 PY 1996 VL 143 IS 3-4 BP 411 EP 419 DI 10.1016/0044-8486(96)01265-3 PG 9 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA VH500 UT WOS:A1996VH50000016 ER PT J AU Guenther, A Baugh, W Davis, K Hampton, G Harley, P Klinger, L Vierling, L Zimmerman, P Allwine, E Dilts, S Lamb, B Westberg, H Baldocchi, D Geron, C Pierce, T AF Guenther, A Baugh, W Davis, K Hampton, G Harley, P Klinger, L Vierling, L Zimmerman, P Allwine, E Dilts, S Lamb, B Westberg, H Baldocchi, D Geron, C Pierce, T TI Isoprene fluxes measured by enclosure, relaxed eddy accumulation, surface layer gradient, mixed layer gradient, and mixed layer mass balance techniques SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID UNITED-STATES; ORGANIC-COMPOUNDS; WATER-VAPOR; EMISSIONS; MODEL; INVENTORY; FOREST; HEAT AB Isoprene fluxes were estimated using eight different measurement techniques at a forested site near Oak Ridge, Tennessee, during July and August 1992. Fluxes from individual leaves and entire branches were estimated with four enclosure systems, including one system that controls leaf temperature and light. Variations in isoprene emission with changes in light, temperature, and canopy depth were investigated with leaf enclosure measurements. Representative emission rates for the dominant vegetation in the region were determined with branch enclosure measurements. Species from six tree genera had negligible Isoprene emissions, while significant emissions were observed for Quercus, Liquidambar, and Nyssa species. Above-canopy isoprene fluxes were estimated with surface layer gradients and relaxed eddy accumulation measurements from a 44-m tower. Midday net emission fluxes from the canopy were typically 3 to 5 mg C m(-2) h(-1), although net isoprene deposition fluxes of -0.2 to 2 mg C m(-2) h(-1) were occasionally observed in early morning and late afternoon. Above-canopy CO2 fluxes estimated by eddy correlation using either an open path sensor or a closed path sensor agreed within +/-5%. Relaxed eddy accumulation estimates of CO2 fluxes were within 15% of the eddy correlation estimates. Daytime isoprene mixing ratios in the mixed layer were investigated with a tethered balloon sampling system and ranged from 0.2 to 5 ppbv, averaging 0.8 ppbv. The isoprene mixing ratios in the mixed layer above the forested landscape were used to estimate isoprene fluxes of 2 to 8 mg C m(-2) h(-1) with mixed layer gradient and mixed layer mass balance techniques. Total foliar density and dominant tree species composition for an approximately 8100 km(2) region were estimated using high-resolution (30 m) satellite data with classifications supervised by ground measurements. A biogenic isoprene emission model used to compare flux measurements, ranging from leaf scale (10 cm(2)) to landscape scale (10(2) km(2)), indicated agreement to within +/-25%, the uncertainty associated with these measurement techniques. Existing biogenic emission models use isoprene emission rate capacities that range from 14.7 to 70 mu g C g(-1) h(-1) (leaf temperature of 30 degrees C and photosynthetically active radiation of 1000 mu mol m(-2) s(-1)) for oak foliage. An isoprene emission rate capacity of 100 mu g C g(-1) h(-1) for oaks in this region is more realistic and is recommended, based on these measurements. C1 WASHINGTON STATE UNIV, DEPT CIVIL & ENVIRONM ENGN, PULLMAN, WA 99164 USA. NOAA, DIV ATMOSPHER TURBULENCE & DIFFUS, OAK RIDGE, TN 37830 USA. US EPA, OFF RES & DEV, RES TRIANGLE PK, NC 27711 USA. RP Guenther, A (reprint author), NATL CTR ATMOSPHER RES, DIV ATMOSPHER CHEM, POB 3000, BOULDER, CO 80307 USA. RI Guenther, Alex/B-1617-2008; Baldocchi, Dennis/A-1625-2009; Harley, Peter/E-1856-2014; Vierling, Lee/E-6428-2010 OI Guenther, Alex/0000-0001-6283-8288; Baldocchi, Dennis/0000-0003-3496-4919; Harley, Peter/0000-0002-2647-1973; Vierling, Lee/0000-0001-5344-1983 NR 22 TC 123 Z9 126 U1 2 U2 19 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD AUG 20 PY 1996 VL 101 IS D13 BP 18555 EP 18567 DI 10.1029/96JD00697 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VD227 UT WOS:A1996VD22700003 ER PT J AU Weaver, A Solomon, S Sanders, RW Arpag, K Miller, HL AF Weaver, A Solomon, S Sanders, RW Arpag, K Miller, HL TI Atmospheric NO3 .5. Off-axis measurements at sunrise: Estimates of tropospheric NO3 at 40 degrees N SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID AIR-MASS FACTORS; STRATOSPHERIC NO3; NEAR-ULTRAVIOLET; MCMURDO STATION; SPECTROSCOPY; CHEMISTRY; SPECTROMETERS; ANTARCTICA; DEPENDENCE; LATITUDE AB The sunrise column abundance of NO3 has been measured at Fritz Peak, Colorado (40 degrees N, 105 degrees W), using visible absorption spectroscopy with scattered sky light as the light source. Measurements were made in the ''off-axis'' configuration, viewing the sky near the horizon. This is a convenient alternative to direct Moon measurements, and the tropospheric component of the total NO3 column can be measured with comparable signal-to-noise levels to the direct Moon data. The average tropospheric NO3 vertical column measured during August-October 1993 was about 4 x 10(13) molecule cm(-2). Assuming a layer 1 km thick in the lowest part of the troposphere, this corresponds to 4 x 10(8) molecule cm(-3), or about 20 pptv. Under these conditions, the nighttime oxidation of isoprene by NO3 is comparable to the daytime oxidation by OH. C1 UNIV COLORADO, COOPERAT INST RES ENVIRONM SCI, BOULDER, CO 80309 USA. RP Weaver, A (reprint author), NOAA, AERON LAB, 325 BROADWAY, R-E-AL8, BOULDER, CO 80303 USA. RI Miller, Henry/D-7628-2013 OI Miller, Henry/0000-0002-7155-8314 NR 30 TC 20 Z9 20 U1 1 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD AUG 20 PY 1996 VL 101 IS D13 BP 18605 EP 18612 DI 10.1029/96JD01537 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VD227 UT WOS:A1996VD22700006 ER PT J AU Russell, PB Livingston, JM Pueschel, RF Bauman, JJ Pollack, JB Brooks, SL Hamill, P Thomason, LW Stowe, LL Deshler, T Dutton, EG Bergstrom, RW AF Russell, PB Livingston, JM Pueschel, RF Bauman, JJ Pollack, JB Brooks, SL Hamill, P Thomason, LW Stowe, LL Deshler, T Dutton, EG Bergstrom, RW TI Global to microscale evolution of the Pinatubo volcanic aerosol derived from diverse measurements and analyses SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Review ID ARCTIC STRATOSPHERIC EXPEDITION; MOUNT-PINATUBO; MT-PINATUBO; SULFURIC-ACID; OPTICAL DEPTH; SIZE DISTRIBUTION; II MEASUREMENTS; TROPICAL OZONE; EL-CHICHON; AVHRR DATA AB We assemble data on the Pinatubo aerosol from space, air, and ground measurements, develop a composite picture, and assess the consistency and uncertainties of measurement and retrieval techniques. Satellite infrared spectroscopy, particle morphology, and evaporation temperature measurements agree with theoretical calculations in showing a dominant composition of H2SO4-H2O mixture, with H2SO4 weight fraction of 65-80% for most stratospheric temperatures and humidities. Important exceptions are (i) volcanic ash, present at all heights initially and just above the tropopause until at least March 1992, and (2) much smaller H2SO4 fractions at the low temperatures of high-latitude winters and the tropical tropopause. Laboratory spectroscopy and calculations yield wavelength- and temperature-dependent refractive indices for the H2SO4-H2O droplets. These permit derivation of particle size information from measured optical depth spectra, for comparison to impactor and optical-counter measurements. All three techniques paint a generally consistent picture of the evolution of R(eff), the effective radius. In the first month after the eruption, although particle numbers increased greatly, R(eff) outside the tropical core was similar to preeruption values of similar to 0.1 to 0.2 mu m, because numbers of both small (r<0.2 mu m) and large (r>0.6 mu m) particles increased. In the next 3-6 months, extracore R(eff) increased to similar to 0.5 mu m, reflecting particle growth through condensation and coagulation. Most data show that R(eff) continued to increase for similar to 1 year after the eruption. R(eff) values up to 0.6-0.8 mu m or more are consistent with 0.38-1 mu m optical depth spectra in middle to late 1992 and even later. However, in this period, values from in situ measurements are somewhat less. The difference might reflect in situ undersampling of the very few largest particles, insensitivity of optical depth spectra to the smallest particles, or the inability of flat spectra to place an upper limit on particle size. Optical depth spectra extending to wavelengths lambda>1 mu m are required to better constrain R(eff), especially for R(eff)>0.4 mu m. Extinction spectra computed from in situ size distributions are consistent with optical depth measurements; both show initial spectra with lambda(max)less than or equal to 0.42 mu m, thereafter increasing to 0.78 less than or equal to lambda(max)less than or equal to 1 mu m. Not until 1993 do spectra begin to show a clear return to the preeruption signature of lambda(max)less than or equal to 0.42 mu m. The twin signatures of large R(eff) (>0.3 mu m) and relatively flat extinction spectra (0.4-1 mu m) are among the longest-lived indicators of Pinatubo volcanic influence. They persist for years after the peaks in number, mass, surface area, and optical depth at all wavelengths less than or equal to 1 mu m. This coupled evolution in particle size distribution and optical depth spectra helps explain the relationship between global maps of 0.5- and 1.0-mu m optical depth derived from the Advanced Very High Resolution Radiometer (AVHRR) and Stratospheric Aerosol and Gas Experiment (SAGE) satellite sensors. However, there are important differences between the AVHRR and SAGE midvisible optical thickness products. We discuss possible reasons for these differences and how they might be resolved. C1 SUNY STONY BROOK, STONY BROOK, NY 11794 USA. BAY AREA ENVIRONM RES INST, SAN FRANCISCO, CA 94122 USA. SYNERNET INC, FREMONT, CA 94538 USA. UNIV WYOMING, DEPT PHYS & ASTRON, LARAMIE, WY 82071 USA. NOAA, CLIMATE MONITORING & DIAGNOST LAB, BOULDER, CO 80303 USA. SAN JOSE STATE UNIV, DEPT PHYS, SAN JOSE, CA 95192 USA. SRI INT, MENLO PK, CA 94025 USA. NOAA, NESDIS, CAMP SPRINGS, MD 20746 USA. NASA, LANGLEY RES CTR, HAMPTON, VA 23681 USA. RP NASA, AMES RES CTR, MAIL STOP 245-5, MOFFETT FIELD, CA 94035 USA. OI Thomason, Larry/0000-0002-1902-0840 NR 107 TC 149 Z9 155 U1 2 U2 20 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD AUG 20 PY 1996 VL 101 IS D13 BP 18745 EP 18763 DI 10.1029/96JD01162 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VD227 UT WOS:A1996VD22700017 ER PT J AU Neuendorffer, AC AF Neuendorffer, AC TI Ozone monitoring with TIROS-N operational vertical sounders SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID UV-B; MODEL; STRATOSPHERE; TOVS AB The potential for using the TIROS-N operational vertical sounder (TOVS) on NOAA polar-orbiting weather satellites to monitor stratospheric ozone is examined. TOVS 9.7-mu m high resolution infrared sounder (HIRS) ozone channel is found to be particularly well suited for monitoring the lower stratospheric ozone layer. A 3 Dobson unit drop in lower stratospheric ozone produces a measurable (i.e., approximate to 0.2 degrees C) increase in HIRS 9.7-mu m brightness temperatures even in the vicinity of Antarctica. A two-layer physical retrieval algorithm is presented that uses the TOVS HIRS 9.7-mu m signal to determine lower stratospheric ozone and to estimate total ozone. Trend analysis of TOVS ozone confirms the fact that there have been significant losses of lower stratospheric ozone in the spring equinox extratropics of both hemispheres. Much of this loss persists into the summer solstice time period. RP Neuendorffer, AC (reprint author), NOAA, OFF RES & APPLICAT,NESDIS SATELLITE RES LAB, CTR SCI,E-RA14, ROOM 810, CAMP SPRINGS, MD 20746 USA. NR 40 TC 26 Z9 26 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD AUG 20 PY 1996 VL 101 IS D13 BP 18807 EP 18828 DI 10.1029/96JD01063 PG 22 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VD227 UT WOS:A1996VD22700022 ER PT J AU Dura, JA Pellegrino, JG Richter, CA AF Dura, JA Pellegrino, JG Richter, CA TI X-ray reflectivity determination of interface roughness correlated with transport properties of (AlGa)As/GaAs high electron mobility transistor devices SO APPLIED PHYSICS LETTERS LA English DT Article AB To explore the role of interface scattering in high electron mobility transistor (HEMT) structure were grown by molecular beam epitaxy (MBE) at temperatures ranging from 500 to 630 degrees C. Hall measurements indicate a trend toward higher mobilities in samples grown at higher temperatures. Subsequent x-ray reflectivity measurements were made, and the data were fitted by least-squares refinement of a calculated reflectivity curve determined from a model of the sample structure to obtain the composition profile along the growth direction. These results indicate smoother interfaces for the samples with higher mobilities. (C) 1996 American Institute of Physics. C1 NATL INST STAND & TECHNOL,DIV SEMICOND ELECT,GAITHERSBURG,MD 20899. RP Dura, JA (reprint author), NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899, USA. RI Dura, Joseph/B-8452-2008 OI Dura, Joseph/0000-0001-6877-959X NR 7 TC 11 Z9 11 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD AUG 19 PY 1996 VL 69 IS 8 BP 1134 EP 1136 DI 10.1063/1.117082 PG 3 WC Physics, Applied SC Physics GA VD023 UT WOS:A1996VD02300038 ER PT J AU Burnett, K Julienne, PS Suominen, KA AF Burnett, K Julienne, PS Suominen, KA TI Laser-driven collisions between atoms in a Bose-Einstein condensed gas SO PHYSICAL REVIEW LETTERS LA English DT Article ID PHOTOASSOCIATIVE SPECTROSCOPY; SCATTERING LENGTH; COOLED ATOMS AB We have determined the rate of loss of atoms from a Bose-Einstein condensed gas due to binary processes in the presence of a far-detuned laser field. In this limit, the binary loss rate spectrum is markedly different from, and can greatly exceed, the basic atomic loss rate. We suggest that measurements of the loss rate spectrum can be used to determine the nature of atom interactions in a condensate. C1 NIST,DIV ATOM PHYS,GAITHERSBURG,MD 20899. HELSINKI UNIV,DEPT PHYS,DIV THEORET PHYS,FIN-00014 HELSINGIN YLIOP,FINLAND. RP Burnett, K (reprint author), UNIV OXFORD,DEPT PHYS,CLARENDON LAB,PARKS RD,OXFORD OX1 3PU,ENGLAND. RI Suominen, Kalle-Antti/H-9076-2012; Julienne, Paul/E-9378-2012 OI Suominen, Kalle-Antti/0000-0002-1091-2893; Julienne, Paul/0000-0002-5494-1442 NR 28 TC 48 Z9 48 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD AUG 19 PY 1996 VL 77 IS 8 BP 1416 EP 1419 DI 10.1103/PhysRevLett.77.1416 PG 4 WC Physics, Multidisciplinary SC Physics GA VC336 UT WOS:A1996VC33600002 ER PT J AU Grayson, DA Tewari, YB Mayhew, MP Vilker, VL Goldberg, RN AF Grayson, DA Tewari, YB Mayhew, MP Vilker, VL Goldberg, RN TI Tetralin as a substrate for camphor (cytochrome p450) 5-monooxygenase SO ARCHIVES OF BIOCHEMISTRY AND BIOPHYSICS LA English DT Article DE camphor 5-monooxygenase; cytochrome P450(cam) hydroxylase; Michaelis-Menten kinetics; solubility; tetralin; thermodynamics ID REDUCTIVE DEHALOGENATION; THERMODYNAMICS; HYDROXYLATION AB Camphor (cytochrome P450) 5-monooxygenase, originally isolated from the bacterium Pseudomonas putida PgG 786, catalyzes the essentially stereospecific conversion of tetralin (1,2,3,4-tetrahydronaphthalene) to (R)-1-tetralol ((R)-(-)-1,2,3,4-tetrahydro-1-naphthol): tetralin(aq) + NADH(aq) + O-2(aq) = (R)-1-tetralol(aq) + NAD(aq) + H2O(1). The ratio of the amount of (S)-1-tetralol to the amount of (R)-1-tetralol is small (approximate to 0.04) and the reaction is essentially stereospecific. The reaction time-course plot indicates the formation of additional product(s) from the (R)-1-tetralol. It is found that the above reaction obeys Michaelis-Menten kinetics and that dimethyl sulfoxide, methanol, and p-dioxane serve as accelerators. Approximate values of a Michaelis constant K-m, limiting rate V-max, and catalytic constant k(cat) are obtained for this reaction under a specified set of conditions. It is shown by means of a thermochemical cycle calculation that the apparent equilibrium constant for this reaction is approximate to 4 x 10(65) at T = 298.15 K and pH 7.3. Thus, this reaction is ''irreversible'' and, unless the enzyme system is inactivated, it will proceed in the direction of complete formation of 1-tetralol from tetralin. A detailed description of the preparation of the camphor (cytochrome P450) 5-monooxygenase enzyme system from recombinant microorganisms is given. (C) 1996 Academic Press, Inc. C1 UNIV CALIF LOS ANGELES,DEPT CHEM ENGN,LOS ANGELES,CA 90095. NIST,DIV BIOTECHNOL,GAITHERSBURG,MD 20899. NR 28 TC 28 Z9 30 U1 0 U2 0 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0003-9861 J9 ARCH BIOCHEM BIOPHYS JI Arch. Biochem. Biophys. PD AUG 15 PY 1996 VL 332 IS 2 BP 239 EP 247 DI 10.1006/abbi.1996.0338 PG 9 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA VB701 UT WOS:A1996VB70100005 PM 8806731 ER PT J AU Zander, R Solomon, S Mahieu, E Goldman, A Rinsland, CP Gunson, MR Abrams, MC Chang, AY Salawitch, RJ Michelsen, HA Newchurch, MJ Stiller, GP AF Zander, R Solomon, S Mahieu, E Goldman, A Rinsland, CP Gunson, MR Abrams, MC Chang, AY Salawitch, RJ Michelsen, HA Newchurch, MJ Stiller, GP TI Increase of stratospheric carbon tetrafluoride (CF4) based on ATMOS observations from space SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID MOLECULE SPECTROSCOPY EXPERIMENT; C2F6; N2O AB Stratospheric volume mixing ratio profiles of carbon tetrafluoride, CF4, obtained with the Atmospheric Trace Molecule Spectroscopy (ATMOS) instrument during the ATLAS (Atmospheric Laboratory for Applications and Science) -3 mission of 1994 are reported. Overall the profiles are nearly constant over the altitude range 20 to 50 km, indicative of the very long lifetime of CF4 in the atmosphere. In comparison to the stratospheric values of CF4 inferred from the ATMOS/Spacelab 3 mission of 1985, the 1994 concentrations are consistent with an exponential increase of (1.6 +/- 0.6)%/yr. This increase is discussed with regard to previous results and likely sources of CF4 at the ground. Further, it is shown that simultaneous measurements of N2O and CF4 provide a means of constraining the lower limit of the atmospheric lifetime of CF4 at least 2,300 years, two sigma. C1 NOAA,AERON LAB,BOULDER,CO 80303. UNIV DENVER,DEPT PHYS,DENVER,CO 80208. HARVARD UNIV,DEPT EARTH & PLANETARY SCI,CAMBRIDGE,MA 02138. UNIV ALABAMA,HUNTSVILLE,AL 35899. NASA,LANGLEY RES CTR,ASD,HAMPTON,VA 23681. IMK,FORSCHUNGSZENTRUM,KARLSRUHE,GERMANY. CALTECH,JET PROP LAB,PASADENA,CA. NASA,LANGLEY RES CTR,SAIC,HAMPTON,VA 23665. RP Zander, R (reprint author), UNIV LIEGE,INST ASTROPHYS,B-4000 LIEGE,BELGIUM. RI Salawitch, Ross/B-4605-2009; Stiller, Gabriele/A-7340-2013; OI Salawitch, Ross/0000-0001-8597-5832; Stiller, Gabriele/0000-0003-2883-6873; Mahieu, Emmanuel/0000-0002-5251-0286 NR 26 TC 24 Z9 25 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD AUG 15 PY 1996 VL 23 IS 17 BP 2353 EP 2356 DI 10.1029/96GL00957 PG 4 WC Geosciences, Multidisciplinary SC Geology GA VD376 UT WOS:A1996VD37600039 ER PT J AU Newchurch, MJ Allen, M Gunson, MR Salawitch, RJ Collins, GB Huston, KH Abbas, MM Abrams, MC Chang, AY Fahey, DW Gao, RS Irion, FW Loewenstein, M Manney, GL Michelsen, HA Podolske, JR Rinsland, CP Zander, R AF Newchurch, MJ Allen, M Gunson, MR Salawitch, RJ Collins, GB Huston, KH Abbas, MM Abrams, MC Chang, AY Fahey, DW Gao, RS Irion, FW Loewenstein, M Manney, GL Michelsen, HA Podolske, JR Rinsland, CP Zander, R TI Stratospheric NO and NO2 abundances from ATMOS solar-occultation measurements SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID DIURNAL-VARIATION; NITRIC-OXIDE; NITROGEN; SPACELAB-3; TWILIGHT; CLO AB Using results from a time-dependent photochemical model to calculate the diurnal variation of NO and NO2, we have corrected Atmospheric Trace MOlecule Spectroscopy (ATMOS) solar-occultation retrievals of the NO and NO2 abundances at 90 degrees solar zenith angle. Neglecting to adjust for the rapid variation of these gases across the terminator results in potential errors in retrieved profiles of similar to 20% for NO2 and greater than 100% for NO at altitudes below 25 km. Sensitivity analysis indicates that knowledge of the local O-3 and temperature profiles, rather than zonal mean or climatological conditions of these quantities, is required to obtain reliable retrievals of NO and NO2 in the lower stratosphere. Extremely inaccurate O-3 or temperature values at 20 km can result in 50% errors in retrieved NO or NO2. Mixing ratios of NO in the mid-latitude, lower stratosphere measured by ATMOS during the November 1994 ATLAS-3 mission compare favorably with in situ ER-2 observations, providing strong corroboration of the reliability of the adjusted space-borne measurements. C1 CALTECH,JET PROP LAB,PASADENA,CA. NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,HUNTSVILLE,AL 35812. NASA,LANGLEY RES CTR,SAIC,HAMPTON,VA 23665. NOAA,AERON LAB,BOULDER,CO 80303. NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. HARVARD UNIV,CAMBRIDGE,MA 02138. UNIV LIEGE,LIEGE,BELGIUM. RP Newchurch, MJ (reprint author), UNIV ALABAMA,EARTH SYST SCI LAB,HUNTSVILLE,AL 35899, USA. RI Salawitch, Ross/B-4605-2009; Gao, Ru-Shan/H-7455-2013; Fahey, David/G-4499-2013 OI Salawitch, Ross/0000-0001-8597-5832; Fahey, David/0000-0003-1720-0634 NR 18 TC 32 Z9 33 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD AUG 15 PY 1996 VL 23 IS 17 BP 2373 EP 2376 DI 10.1029/96GL01196 PG 4 WC Geosciences, Multidisciplinary SC Geology GA VD376 UT WOS:A1996VD37600044 ER PT J AU Chang, AY Salawitch, RJ Michelsen, HA Gunson, MR Abrams, MC Zander, R Rinsland, CP Loewenstein, M Podolske, JR Proffitt, MH Margitan, JJ Fahey, DW Gao, RS Kelly, KK Elkins, JW Webster, CR May, RD Chan, KR Abbas, MM Goldman, A Irion, FW Manney, GL Newchurch, MJ Stiller, GP AF Chang, AY Salawitch, RJ Michelsen, HA Gunson, MR Abrams, MC Zander, R Rinsland, CP Loewenstein, M Podolske, JR Proffitt, MH Margitan, JJ Fahey, DW Gao, RS Kelly, KK Elkins, JW Webster, CR May, RD Chan, KR Abbas, MM Goldman, A Irion, FW Manney, GL Newchurch, MJ Stiller, GP TI A comparison of measurements from ATMOS and instruments aboard the ER-2 aircraft: Tracers of atmospheric transport SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID ANTARCTIC OZONE EXPERIMENT; WATER AB We compare volume mixing ratio profiles of N2O, O-3, NOy, H2O, CH4, and CO in the mid-latitude lower stratosphere measured by the ATMOS Fourier transform spectrometer on the ATLAS-3 Space Shuttle Mission with in situ measurements acquired from the NASA ER-2 aircraft during Nov 1994. ATMOS and ER-2 observations of [N2O] show good agreement, as do measured correlations of [O-3], [NOy], [H2O], and [CH4] with [N2O]. Thus a consistent measure of the hydrogen (H2O, CH4) content of the lower stratosphere is provided by the two platforms. The similarity of [NOy] determined by detection of individual species by ATMOS and the total [NOy] measurement on the ER-2 provides strong corroboration for the accuracy of both techniques. A 25% discrepancy in lower stratospheric [CO] observed by ATMOS and the ER-2 remains unexplained. Otherwise, the agreement for measurements of long-lived tracers demonstrates the ability to combine ATMOS data with in situ observations for quantifying atmospheric transport. C1 HARVARD UNIV,CAMBRIDGE,MA 02138. NASA,LANGLEY RES CTR,SAIC,HAMPTON,VA 23665. UNIV LIEGE,INST ASTROPHYS,LIEGE,BELGIUM. NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. NOAA,AERON LAB,BOULDER,CO 80303. UNIV COLORADO,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. NOAA,CLIMATE MONITORING & DIAGNOST LAB,BOULDER,CO 80303. NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,HUNTSVILLE,AL 35812. UNIV DENVER,DEPT PHYS,DENVER,CO 80208. UNIV ALABAMA,HUNTSVILLE,AL 35899. IMK,FORSCHUNGSZENTRUM,KARLSRUHE,GERMANY. RP Chang, AY (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,MS,PASADENA,CA 91109, USA. RI Salawitch, Ross/B-4605-2009; Stiller, Gabriele/A-7340-2013; Gao, Ru-Shan/H-7455-2013; Fahey, David/G-4499-2013 OI Salawitch, Ross/0000-0001-8597-5832; Stiller, Gabriele/0000-0003-2883-6873; Fahey, David/0000-0003-1720-0634 NR 8 TC 35 Z9 35 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD AUG 15 PY 1996 VL 23 IS 17 BP 2389 EP 2392 DI 10.1029/96GL01677 PG 4 WC Geosciences, Multidisciplinary SC Geology GA VD376 UT WOS:A1996VD37600048 ER PT J AU Chang, AY Salawitch, RJ Michelsen, HA Gunson, MR Abrams, MC Zander, R Rinsland, CP Elkins, JW Dutton, GS Volk, CM Webster, CR May, RD Fahey, DW Gao, RS Loewenstein, M Podolske, JR Stimpfle, RM Kohn, DW Proffitt, MH Margitan, JJ Chan, KR Abbas, MM Goldman, A Irion, FW Manney, GL Newchurch, MJ Stiller, GP AF Chang, AY Salawitch, RJ Michelsen, HA Gunson, MR Abrams, MC Zander, R Rinsland, CP Elkins, JW Dutton, GS Volk, CM Webster, CR May, RD Fahey, DW Gao, RS Loewenstein, M Podolske, JR Stimpfle, RM Kohn, DW Proffitt, MH Margitan, JJ Chan, KR Abbas, MM Goldman, A Irion, FW Manney, GL Newchurch, MJ Stiller, GP TI A comparison of measurements from ATMOS and instruments aboard the ER-2 aircraft: Halogenated gases SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID LOWER STRATOSPHERE; REACTIVE NITROGEN; CHLORINE AB We compare volume mixing ratio profiles of N2O, CFC-11, CFC-12, CCl4, SF6, and HCl in the mid-latitude lower stratosphere measured by the ATMOS Fourier transform spectrometer on the ATLAS-3 Space Shuttle Mission with in situ measurements acquired from the NASA ER-2 aircraft during Nov 1994. Good agreement is found between ATMOS and in situ correlations of [CFC-II], [CFC-12], and [SF6] with [N2O]. ATMOS measurements of [CCl4] are 15% high compared to ER-2 data, but agree within the systematic uncertainties. ATMOS observations of [HCl] vs [N2O] are within similar to 10% of ER-2 data for [HCl] > 1 ppbv, but exceed in situ measurements by larger fractional amounts for smaller [HCl]. ATMOS measurements of [ClONO2] agree well with values inferred from in situ observations of [ClO], [NO], and [O-3]. The sum of [HCl] and [ClONO2] observed by ATMOS, supplemented by a minor contribution from [ClO] estimated with a photochemical model, is consistent with the levels of inorganic chlorine inferred from in situ measurements of chlorine source gases. C1 HARVARD UNIV,CAMBRIDGE,MA 02138. NASA,LANGLEY RES CTR,SAIC,HAMPTON,VA 23665. UNIV LIEGE,INST ASTROPHYS,LIEGE,BELGIUM. NOAA,CLIMATE MONITORING & DIAGNOST LAB,BOULDER,CO 80303. UNIV COLORADO,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. NOAA,AERON LAB,BOULDER,CO 80303. NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,HUNTSVILLE,AL 35812. UNIV DENVER,DEPT PHYS,DENVER,CO 80208. UNIV ALABAMA,HUNTSVILLE,AL 35899. IMK,FORSCHUNGSZENTRUM,KARLSRUHE,GERMANY. RP Chang, AY (reprint author), CALTECH,JET PROPULS LAB,4800 OAK GROVE DR,MS,PASADENA,CA 91109, USA. RI Salawitch, Ross/B-4605-2009; Stiller, Gabriele/A-7340-2013; Gao, Ru-Shan/H-7455-2013; Fahey, David/G-4499-2013 OI Salawitch, Ross/0000-0001-8597-5832; Stiller, Gabriele/0000-0003-2883-6873; Fahey, David/0000-0003-1720-0634 NR 13 TC 26 Z9 26 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD AUG 15 PY 1996 VL 23 IS 17 BP 2393 EP 2396 DI 10.1029/96GL01678 PG 4 WC Geosciences, Multidisciplinary SC Geology GA VD376 UT WOS:A1996VD37600049 ER PT J AU Gilles, MK Turnipseed, AA Talukdar, RK Rudich, Y Villalta, PW Huey, LG Burkholder, JB Ravishankara, AR AF Gilles, MK Turnipseed, AA Talukdar, RK Rudich, Y Villalta, PW Huey, LG Burkholder, JB Ravishankara, AR TI Reactions of O(P-3) with alkyl iodides: Rate coefficients and reaction products SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID LASER-INDUCED FLUORESCENCE; ABSORPTION CROSS-SECTIONS; OZONE DEPLETION; QUANTUM YIELDS; RATE-CONSTANT; 222 NM; KINETICS; CF3I; PHOTOCHEMISTRY; PHOTOLYSIS AB The rate coefficients for the reactions of O(P-3) with CF3I (1) and CH3I (2) were measured between 213 and 364 K to be: k(1)(T) = (7.9 +/- 0.8) x 10(-12) exp[-(175 +/- 40)/T] and k(2)(T) = (1.0 +/- 0.2) x 10(-11) exp[(160 +/- 50)/T] cm(3) molecule(-1) s(-1). The rate coefficients for the reaction of O(P-3) with CD3I, (CH3)(2)CHCH2I,(CH3)(2)CHI, CF3CH2I, CF3CHFI, and CF3CF2I at 298 K were also measured. The yields of the IO and CF3O products in reaction 1 at 298 K were found to be 0.83 +/- 0.09 and <0.01, respectively. Product yields of reaction 2 at 298 K were measured to be IO (0.44 +/- 0.04), OH (0.16 +/- 0.05), H (0.07 +/- 0.02), CH3O (<0.03), and HI (<0.05). IO, OH, and CH3O were detected via laser-induced fluorescence, O and H atoms via resonance fluorescence, and IO, CF3O, and HI by chemical ionization mass spectrometry. The IO yield from reactions 1 and 2 showed a slight positive temperature dependence. Within our experimental error the OH yield from reaction 2 was temperature independent. An upper limit for the enthalpy of formation of IO, Delta(f)H(o)(298.15 K)(IO) <28.8 kcal mol(-1), was obtained from an interpretation of our data. C1 NOAA,AERON LAB,BOULDER,CO 80303. UNIV COLORADO,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309. UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. RI Rudich, Yinon/K-1498-2012; TALUKDAR, RANAJIT/G-4530-2013; Burkholder, James/H-4914-2013; Ravishankara, Akkihebbal/A-2914-2011 OI TALUKDAR, RANAJIT/0000-0001-6017-8431; NR 49 TC 90 Z9 91 U1 2 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD AUG 15 PY 1996 VL 100 IS 33 BP 14005 EP 14015 DI 10.1021/jp960688v PG 11 WC Chemistry, Physical SC Chemistry GA VC550 UT WOS:A1996VC55000020 ER PT J AU Chen, P AF Chen, P TI The influences of zonal flow on wave breaking and tropical-extratropical interaction in the lower stratosphere SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID QUASI-BIENNIAL OSCILLATION; MIDDLE LATITUDES; PLANETARY-WAVES; POLAR VORTEX; SURF ZONE; CIRCULATION; SIMULATION; TRANSPORT; AEROSOL; MODEL AB The influences of the zonal-mean flow on Rossby wave breaking and tropical-extratropical interaction in the lower stratosphere are investigated using a high-resolution barotropic model. It is found that the zonal-mean wind in the subtropics of the winter hemisphere, denoted as <(u)over bar (30 degrees)>, is pivotal to the location and intensity of Rossby wave breaking. When <(u)over bar (30 degrees)> is positive and relatively large, significant wave breaking occurs in two regions: one in the midlatitudes of the winter hemisphere and the other in the Tropics. When <(u)over bar (30 degrees)> is small or negative. on the other hand, wave breaking occurs primarily in the middle-to-high latitudes of the winter hemisphere. It is also found that when <(u)over bar (30 degrees)> is large, wave breaking is sensitive to the phase of the equatorial quasi-biennial oscillation (QBO) in that if the QBO is westerly, significant wave breaking takes place in the midlatitudes of the winter hemisphere and the subtropics of the summer hemisphere and no wave breaking occurs in the equatorial region, and if the QBO is easterly, significant wave breaking occurs only in the winter hemisphere. When <(u)over bar (30 degrees)> is small or negative, wave breaking is insensitive to the phase of the QBO. RP Chen, P (reprint author), UNIV COLORADO, CIRES, NOAA, CAMPUS BOX 449, BOULDER, CO 80309 USA. NR 39 TC 21 Z9 21 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD AUG 15 PY 1996 VL 53 IS 16 BP 2379 EP 2392 DI 10.1175/1520-0469(1996)053<2379:TIOZFO>2.0.CO;2 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA VE238 UT WOS:A1996VE23800006 ER PT J AU Ramaswamy, V Schwarzkopf, MD Randel, WJ AF Ramaswamy, V Schwarzkopf, MD Randel, WJ TI Fingerprint of ozone depletion in the spatial and temporal pattern of recent lower-stratospheric cooling SO NATURE LA English DT Article ID GENERAL-CIRCULATION MODEL; TEMPERATURE TRENDS; TROPOSPHERE; CLIMATE; HOLE AB OBSERVATIONS of air temperatures in the lower stratosphere from 1979 to 1990 reveal a cooling trend that varies both spatially and seasonally(1). The possible causes of this cooling include changes in concentrations of ozone or of other greenhouse gases(2,3), and entirely natural variability, but the relative contributions of such causes are poorly constrained. Here we incorporate the observed decreases in stratospheric ozone concentrations(4) over the same period into a general circulation model of the atmosphere, to investigate the role of the ozone losses in affecting patterns of temperature change. We find that the simulated latitudinal pattern of lower-stratospheric cooling for a given month through the decade corresponds well with the pattern of the observed decadal temperature changes, This result confirms the expectation, from simpler model studies(2,3,5), that the observed ozone depletion exerts a spatially and seasonally varying fingerprint in the decadal cooling of the lower stratosphere, with the influence of increases in concentrations of other greenhouse gases being relatively small. As anthropogenic halocarbon chemicals are important causes of stratospheric ozone depletion(2,3), our study suggests a human influence on the patterns of temperature change in the lower stratosphere over this 11-year period. C1 NATL CTR ATMOSPHER RES,BOULDER,CO 80307. RP Ramaswamy, V (reprint author), PRINCETON UNIV,NOAA,GEOPHYS FLUID DYNAM LAB,PRINCETON,NJ 08542, USA. RI Randel, William/K-3267-2016 OI Randel, William/0000-0002-5999-7162 NR 31 TC 94 Z9 99 U1 2 U2 6 PU MACMILLAN MAGAZINES LTD PI LONDON PA 4 LITTLE ESSEX STREET, LONDON, ENGLAND WC2R 3LF SN 0028-0836 J9 NATURE JI Nature PD AUG 15 PY 1996 VL 382 IS 6592 BP 616 EP 618 DI 10.1038/382616a0 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA VC303 UT WOS:A1996VC30300049 ER PT J AU Tachikawa, M Evenson, KM AF Tachikawa, M Evenson, KM TI Sequential optical pumping of a far-infrared ammonia laser SO OPTICS LETTERS LA English DT Article ID CW; NH3 AB We present a novel technique for resonantly pumping a continuous-wave far-infrared NH3 laser with a line-tunable mid-infrared NH3 laser that is optically pumped by a CO2 laser. In this two-step process we first convert 10-mu m CO2 laser photons into 11-13-mu m NH3 laser photons, which are then converted into 60-400-mu m photons in a far-infrared NH3 laser. Continuous-wave laser action on 10 far-infrared lines of (NH3)-N-15, including four new ones, has been obtained with a single CO2 laser pump line. RP Tachikawa, M (reprint author), NATL INST STAND & TECHNOL,DIV TIME & FREQUENCY,325 BROADWAY,BOULDER,CO 80303, USA. NR 20 TC 2 Z9 2 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD AUG 15 PY 1996 VL 21 IS 16 BP 1247 EP 1249 DI 10.1364/OL.21.001247 PG 3 WC Optics SC Optics GA VA997 UT WOS:A1996VA99700015 PM 19876314 ER PT J AU Ye, J Swartz, S Jungner, P Hall, JL AF Ye, J Swartz, S Jungner, P Hall, JL TI Hyperfine structure and absolute frequency of the Rb-87 5P(3/2) state SO OPTICS LETTERS LA English DT Article ID SATURATION SPECTROSCOPY; NM AB We have constructed two highly stable and reproducible Rb-87 D-2-Saturated-absorption spectrometers at 780 nm, using dither/third-harmonic lock-in detection and radio-frequency sideband techniques, respectively. We achieved +/-3-kHz reproducibility and agreement between these two independent systems. Heterodyne measurements of the hyperfine splittings of the 5P(3/2) state give its magnetic dipole (A) and electric quadrupole (B) hyperfine constants with a 10-fold reduction in uncertainty. (C) 1996 Optical Society of America C1 UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. NATL INST STAND & TECHNOL,BOULDER,CO 80309. RI Ye, Jun/C-3312-2011 NR 14 TC 164 Z9 167 U1 0 U2 20 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD AUG 15 PY 1996 VL 21 IS 16 BP 1280 EP 1282 DI 10.1364/OL.21.001280 PG 3 WC Optics SC Optics GA VA997 UT WOS:A1996VA99700026 PM 19876325 ER PT J AU Frey, M Simiu, E AF Frey, M Simiu, E TI Phase space transport and control of escape from a potential well SO PHYSICA D LA English DT Article DE control; stability; chaos; escape ID PERTURBATIONS; CHAOS AB A framework for controlling a nonlinear dynamical system against escape from a potential well is presented based on reducing the phase space transport across the separatrix associated with the potential well. A bandlimited open-loop control with finite lag is considered for systems with weak additive stationary forcing including, specifically, the colored Gaussian case. The related multiplicative, closed-loop control problem is shown to reduce to an open-loop problem. A numerical example based on the Duffing oscillator is presented to illustrate the theory. C1 NATL INST STAND & TECHNOL,STRUCT DIV,BLDG & FIRE RES LAB,GAITHERSBURG,MD 20899. RP Frey, M (reprint author), BUCKNELL UNIV,DEPT MATH,LEWISBURG,PA 17837, USA. NR 18 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2789 J9 PHYSICA D JI Physica D PD AUG 15 PY 1996 VL 95 IS 2 BP 128 EP 143 DI 10.1016/0167-2789(96)00067-X PG 16 WC Mathematics, Applied; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA VC047 UT WOS:A1996VC04700003 ER PT J AU Rosenberg, A Tonucci, RJ Lin, HB Shirley, EL AF Rosenberg, A Tonucci, RJ Lin, HB Shirley, EL TI Photonic-band-structure effects for low-index-contrast two-dimensional lattices in the near-infrared SO PHYSICAL REVIEW B LA English DT Article ID ARRAY; GAPS AB We demonstrate that two-dimensional periodic dielectric structures with low index contrast give rise to remarkable photonic band-structure effects. Our structures consist of triangular arrays of glass cylinders embedded in a matrix composed of a different glass, having center-to-center nearest-neighbor separations from 1.08 mu m to 0.54 mu m. The indices of refraction of the two glasses differ by less than 0.02 in the relevant spectral region. The attenuation features corresponding to the boundaries of the first Brillouin zone appear in the near-infrared, at photon energies between 0.4 eV and 0.9 eV. C1 NIST, GAITHERSBURG, MD 20899 USA. RP Rosenberg, A (reprint author), USN, RES LAB, WASHINGTON, DC 20375 USA. NR 11 TC 26 Z9 26 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD AUG 15 PY 1996 VL 54 IS 8 BP R5195 EP R5198 PG 4 WC Physics, Condensed Matter SC Physics GA VF929 UT WOS:A1996VF92900001 ER PT J AU Brant, P Karim, A Douglas, JF Bates, FS AF Brant, P Karim, A Douglas, JF Bates, FS TI Surface composition of amorphous and crystallizable polyethylene blends as measured by static SIMS SO MACROMOLECULES LA English DT Article ID ION MASS-SPECTROMETRY; POLYMER BLENDS; BLOCK-COPOLYMERS; SPECTROSCOPY; ETHYLENE; SEGREGATION; POLYSTYRENE; BEHAVIOR; MIXTURES; SYSTEMS AB The surface composition of several thin-film semicrystalline polyolefin blends is quantified using secondary ion mass spectroscopy(SIMS). These experiments indicate that the component having the lower crystallinity migrates to the free surface so that the degree of crystallinity is an important factor along with the local polymer-polymer interaction and chain stiffness in determining the surface segregation in polymer blends. Specifically, a systematic study involving mixtures of amorphous polymers [poly(ethylethylene) (PEE), poly(ethylenepropylene) (PEP), and poly(ethylene-co-(1-dodecene)) (EC12)] with semicrystalline model polyethylenes (PE) having various densities (crystalline content! showed the greatest degree of surface enrichment for the amorphous polymers PEE and EC12 and to a lesser degree PEP. The degree of surface segregation for the E materials, was higher for the lower density materials which have a higher amorphous content. Surface enrichment of amorphous component as high as 50-fold was observed. SIMS measurements thus show a definite heirarchy in the degree of surface enrichment according to the degree of crystallinity as well as the relative chain stiffness of the blend components in these model polymer systems. C1 NIST,DIV POLYMERS,GAITHERSBURG,MD 20899. UNIV MINNESOTA,DEPT CHEM ENGN & MAT SCI,MINNEAPOLIS,MN 55455. RP Brant, P (reprint author), EXXON CHEM CO,BAYTOWN POLYMERS CTR,BAYTOWN,TX 77522, USA. OI Bates, Frank/0000-0003-3977-1278 NR 44 TC 34 Z9 35 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD AUG 12 PY 1996 VL 29 IS 17 BP 5628 EP 5634 DI 10.1021/ma951349n PG 7 WC Polymer Science SC Polymer Science GA VC269 UT WOS:A1996VC26900018 ER PT J AU Guttman, CM DiMarzio, EA Douglas, JF AF Guttman, CM DiMarzio, EA Douglas, JF TI Influence of polymer architecture and polymer-surface interaction on the elution chromatography of macromolecules through a microporous media SO MACROMOLECULES LA English DT Article ID GEL-PERMEATION CHROMATOGRAPHY; CRITICAL END-POINTS; LIQUID-CHROMATOGRAPHY; CRITICAL RANGE; LOCALIZATION MODEL; RUBBER ELASTICITY; EXCLUDED VOLUME; SMALL PORES; FILMS; SEPARATION AB The elution chromatography of flexible polymer molecules flowing through a microporous particle media is described by a combination of the Casassa model of flow segregation and the Di Marzio-Rubin lattice method for calculating the partition function of confined polymers. This combination of models allows for the treatment of polymer-surface interactions so that polymer chromatography in the exclusion and adsorption regimes can be described within a unified framework. The compensation point where repulsive polymer-surface excluded volume forces and short-range polymer surface attractive forces counterbalance each other offers opportunities for separating complex molecules. For example, calculations for a diblock copolymer where one of the components is at the compensation point (''adsorption Theta point'') indicate that only the remaining block influences the elution of the block copolymer as a whole. This theoretical result accords with experiments on block copolymers. This singular observation provides support for the Casassa viewpoint of molecular partitioning dominated polymer elution. The chromatography of triblock copolymers, stars, and combs is also examined to determine the selectivity of elution chromatography for separating these molecular architectures. The theoretical development in the present paper should lead to improved methods for the characterization of polymers with different molecular architectures. These developments also suggest new tools for studying polymer adsorption from dilute solution. RP Guttman, CM (reprint author), NIST,DIV POLYMERS,GAITHERSBURG,MD 20899, USA. NR 71 TC 64 Z9 64 U1 2 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD AUG 12 PY 1996 VL 29 IS 17 BP 5723 EP 5733 DI 10.1021/ma9602029 PG 11 WC Polymer Science SC Polymer Science GA VC269 UT WOS:A1996VC26900030 ER PT J AU Wenthold, PG Gunion, RF Lineberger, WC AF Wenthold, PG Gunion, RF Lineberger, WC TI Ultraviolet negative-ion photoelectron spectroscopy of the chromium oxide negative ion SO CHEMICAL PHYSICS LETTERS LA English DT Article ID ROTATIONAL ANALYSIS; METAL-OXIDES; CRO; TRANSITION AB The photoelectron spectrum of CrO- is reported, with four electron states of CrO detected. The (5) Pi ground state of CrO has an electron affinity of 1.221 +/- 0.006 eV. An excited (3) Pi state is also observed, which lies 8600 +/- 40 cm(-1) above the ground state. Two additional states of CrO, believed to be triplets, are observed at energies of 4835 +/- 80 and 7365 +/- 40 cm(-1), respectively. C1 UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. RP Wenthold, PG (reprint author), UNIV COLORADO,JOINT INST LAB ASTROPHYS,NATL INST STAND & TECHNOL,BOULDER,CO 80309, USA. NR 14 TC 36 Z9 36 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD AUG 9 PY 1996 VL 258 IS 1-2 BP 101 EP 106 DI 10.1016/0009-2614(96)00611-2 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VB494 UT WOS:A1996VB49400015 ER PT J AU Anderson, DT Davis, S Zwier, TS Nesbitt, DJ AF Anderson, DT Davis, S Zwier, TS Nesbitt, DJ TI An intense slit discharge source of jet-cooled molecular ions and radicals (T-rot<30K) SO CHEMICAL PHYSICS LETTERS LA English DT Article ID INFRARED-ABSORPTION SPECTROSCOPY; EXCITED SUPERSONIC EXPANSION; LASER SPECTROSCOPY; OH; DEPLETION AB A novel pulsed, slit supersonic discharge source is described for generating intense jet-cooled densities of radicals (> 10(12)/cm(3)) and molecular ions (> 10(10)/cm(3)) under long absorption path (80 cm), supersonically cooled conditions. The design confines the discharge region upstream of the supersonic expansion orifice to achieve efficient rotational cooling down to 30 K or less. The collisionally collimated velocity distribution in the slit discharge geometry yields sub-Doppler spectral linewidths, which for open-shell radicals reveals spin-rotation splittings and broadening due to nuclear hyperfine structure. Application of the slit source for high-resolution, direct IR laser absorption spectroscopy in discharges is demonstrated on species such as OH, H3O+ and N2H+. C1 UNIV COLORADO, DEPT CHEM & BIOCHEM, BOULDER, CO 80309 USA. PURDUE UNIV, DEPT CHEM, W LAFAYETTE, IN 47907 USA. UNIV COLORADO, NATL INST STAND & TECHNOL, QUANTUM PHYS DIV, BOULDER, CO 80309 USA. RP UNIV COLORADO, JILA, BOULDER, CO 80309 USA. NR 23 TC 57 Z9 58 U1 0 U2 10 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 EI 1873-4448 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD AUG 9 PY 1996 VL 258 IS 1-2 BP 207 EP 212 DI 10.1016/0009-2614(96)00633-1 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VB494 UT WOS:A1996VB49400032 ER PT J AU Knowles, MP Leone, SR AF Knowles, MP Leone, SR TI Hyperthermal (1-10 eV) cobalt deposition on Si(100) SO CHEMICAL PHYSICS LETTERS LA English DT Article ID EPITAXIAL SILICIDES; GROWTH; INTERFACE; SILICON; ENERGY; FILMS; BEAMS AB Cobalt atoms with enhanced kinetic energy (1-10 eV) are deposited on room temperature Si(100) and compared to thermal energy cobalt atom deposition. Growth is monitored with Auger electron spectroscopy and low-energy electron diffraction. At low cobalt coverages, 2 monolayers (ML), thermal deposition measurements agree with previous work where uptake at surface sites occurs up to approximate to 0.5 ML, followed by filling subsurface sites. Auger data suggest that hyperthermal deposition occurs by direct subsurface adsorption. C1 UNIV COLORADO,BOULDER,CO 80309. UNIV COLORADO,DEPT CHEM & BIOCHEM,BOULDER,CO 80309. RP Knowles, MP (reprint author), NATL INST STAND & TECHNOL,JILA,QUANTUM PHYS DIV,325 BROADWAY,BOULDER,CO 80309, USA. NR 26 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD AUG 9 PY 1996 VL 258 IS 1-2 BP 217 EP 222 DI 10.1016/0009-2614(96)00637-9 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VB494 UT WOS:A1996VB49400034 ER PT J AU Nackerdien, Z Atha, D AF Nackerdien, Z Atha, D TI Measurement of Co-60-gamma ray-induced DNA damage by capillary electrophoresis SO JOURNAL OF CHROMATOGRAPHY B-BIOMEDICAL APPLICATIONS LA English DT Article; Proceedings Paper CT 6th Annual Frederick Conference on Capillary Electrophoresis CY OCT 23-25, 1995 CL FREDERICK, MD DE DNA; (60)cobalt ID FLUORESCENCE DETECTION; RADIATION; FRAGMENTS AB Capillary electrophoresis was employed in this study to monitor Co-60-gamma ray-induced damage to a 1 kb DNA ladder which consists of restriction fragments ranging from 75 to 12 000 bp. DNA samples (0.5 mg/ml) were exposed to 0-60 Gy of gamma-radiation in the presence and absence of 110 mu mol/l ethidium bromide (EB). The analysis showed peak broadening without significant changes in the size distribution of irradiated fragments. Radiation-induced conformational changes may account for this peak broadening. EB addition caused small increases in the retention times of DNA fragments without affecting the overall DNA damage. This indicates that the presence of intercalated EB during radiation will not stabilize the DNA against Co-60-gamma ray-induced damage. RP Nackerdien, Z (reprint author), NIST,DIV BIOTECHNOL,BLDG 222-A353,GAITHERSBURG,MD 20899, USA. NR 20 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-4347 J9 J CHROMATOGR B JI J. Chromatogr. B-Biomed. Appl. PD AUG 9 PY 1996 VL 683 IS 1 BP 85 EP 89 DI 10.1016/0378-4347(96)00127-2 PG 5 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA VD586 UT WOS:A1996VD58600010 PM 8876442 ER PT J AU Nackerdien, Z Morris, S Choquette, S Ramos, B Atha, D AF Nackerdien, Z Morris, S Choquette, S Ramos, B Atha, D TI Analysis of laser-induced plasmid DNA photolysis by capillary electrophoresis SO JOURNAL OF CHROMATOGRAPHY B-BIOMEDICAL APPLICATIONS LA English DT Article; Proceedings Paper CT 6th Annual Frederick Conference on Capillary Electrophoresis CY OCT 23-25, 1995 CL FREDERICK, MD DE DNA photolysis; plasmid DNA; capillary electrophoresis ID FLUORESCENCE DETECTION; GEL-ELECTROPHORESIS; RADIATION; DAMAGE AB Capillary electrophoresis (CE) was used to monitor the laser-induced conversion of supercoiled pKOL8UVS plasmid DNA into nicked conformers. The plasmid samples (0.1 mg/ml) were incubated in the absence or presence of 110 mu mol/l ethidium bromide (EB) and then exposed to 110 J of argon laser radiation (488 nm). The nicked, open circular conformers were separated from the supercoiled DNA by a 15% increase in retention time. Approximately 90% of the control DNA was in the supercoiled form. Laser radiation in the presence of EB caused complete conversion of the supercoiled plasmid DNA into nicked conformers. Laser-induced fluorescence CE (LIF-CE) was about 100-fold more sensitive than UV-CE in the detection of these conformers. Agarose gel electrophoresis confirmed these findings and showed the presence of the nicked plasmid conformers. Based on these comparisons, CE is an efficient analytical tool for the identification of laser-induced conformational changes in plasmid DNA. C1 NIST,DIV ANALYT CHEM,GAITHERSBURG,MD 20899. BIORES OPERAT,BECKMAN INSTRUMENTS,COLUMBIA,MD 21045. RP Nackerdien, Z (reprint author), NIST,DIV BIOTECHNOL,GAITHERSBURG,MD 20899, USA. NR 9 TC 18 Z9 19 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-4347 J9 J CHROMATOGR B JI J. Chromatogr. B-Biomed. Appl. PD AUG 9 PY 1996 VL 683 IS 1 BP 91 EP 96 DI 10.1016/0378-4347(95)00584-6 PG 6 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA VD586 UT WOS:A1996VD58600011 PM 8876443 ER PT J AU Lugez, CL Thompson, WE Jacox, ME AF Lugez, CL Thompson, WE Jacox, ME TI Matrix isolation study of the interaction of excited neon atoms with O-3: Infrared spectrum of O-3(-) and evidence for the stabilization of O-2 center dot center dot center dot O-4(+) SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID POTENTIAL-ENERGY SURFACES; COUPLED-CLUSTER METHOD; SOLID NEON; VIBRATIONAL-SPECTRA; ARGON MATRIX; PHOTOELECTRON-SPECTROSCOPY; PHOTO-DISSOCIATION; ELECTRONIC STATES; OZONE CATION; IONS AB When a Ne:O-3 sample is codeposited at approximately 5 K with neon atoms that have been excited in a microwave discharge, the most prominent infrared absorptions of the resulting solid are contributed by trans- and cyc-O-4(+) and by O-3(-). The failure to detect infrared absorptions of O-3(+) is consistent with the initial formation of that species in one or more dissociative excited states. The nu(3) absorption of O-3(-) appears at 796.3 cm(-1), close to its position in earlier argon-matrix experiments in which photoionization of an alkali metal atom provided the electron source and in which diffusion of the atomic cation would result in the stabilization of appreciable M(+)O(3)(-). The identification of O-3(-) isolated in solid neon is supported by observations of O-3(-) generated from isotopically substituted Ne:O-2:N2O samples, also codeposited with excited neon atoms. An upper bound of 810 cm(-1) is estimated for the gas-phase band center of nu(3) of O-3(-). Infrared absorptions which grow on mild warmup of the sample are tentatively assigned to an O-2 ... O-4(+) complex. (C) 1996 American Institute of Physics. RP Lugez, CL (reprint author), NIST,DIV MOL PHYS,GAITHERSBURG,MD 20899, USA. NR 61 TC 19 Z9 19 U1 0 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD AUG 8 PY 1996 VL 105 IS 6 BP 2153 EP 2160 DI 10.1063/1.472533 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VA913 UT WOS:A1996VA91300003 ER PT J AU Vorsa, V Campagnola, PJ Nandi, S Larsson, M Lineberger, WC AF Vorsa, V Campagnola, PJ Nandi, S Larsson, M Lineberger, WC TI Photofragmentation of I-2(-)center dot Ar-n clusters: Observation of metastable isomeric ionic fragments SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID RARE-GAS CLUSTERS; CHARGED ARGON CLUSTERS; SOLVATION ULTRAFAST DYNAMICS; CARBON-DIOXIDE CLUSTERS; KINETIC-ENERGY RELEASE; MAGIC NUMBERS; PHOTOELECTRON-SPECTROSCOPY; RECOMBINATION DYNAMICS; GEMINATE RECOMBINATION; BINDING-ENERGIES AB We report the 790 nm photofragmentation of mass-selected I-2(-). Ar-n clusters, n=1 to 27. We determine the I-+I caging efficiency as a function of the number of solvent Ar atoms and compare these results with I-2(-) in CO2 clusters. Caging is much less effective with Ar. In addition to ''normal'' caged photoproducts (I-2(-). Ar-m, where m5 mu s, This unusual photofragment exists either as a trapped excited electronic state or as a solvent-separated pair at an internuclear separation of similar to 5.5 Angstrom. The photofragmentation data also exhibit the existence of two distinct isomeric forms of the precursor I-2(-). Ar-n, for n less than or equal to 14. These forms are evaporatively distinct in that one isomer displays highly nonstatistical fragmentation, probably arising from a cluster in which the I-2(-) resides on the surface, rather than in the interior. The photofragmentation distribution of the other form exhibits statistical behavior, consistent with the evaporation of an I-2(-) solvated inside the cluster. (C) 1996 American Institute of Physics. C1 UNIV COLORADO,JILA,BOULDER,CO 80309. NATL INST STAND & TECHNOL,BOULDER,CO 80309. RP Vorsa, V (reprint author), UNIV COLORADO,DEPT CHEM & BIOCHEM,CAMPUS BOX 215,BOULDER,CO 80309, USA. NR 71 TC 76 Z9 76 U1 1 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD AUG 8 PY 1996 VL 105 IS 6 BP 2298 EP 2308 DI 10.1063/1.472098 PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA VA913 UT WOS:A1996VA91300017 ER PT J AU Guldi, DM Field, J Grodkowski, J Neta, P Vogel, E AF Guldi, DM Field, J Grodkowski, J Neta, P Vogel, E TI One-electron oxidation of metalloporphycenes as studied by radiolytic methods SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID CHROMIUM(III) PORPHYRINS; NICKEL PORPHYRINS; PULSE-RADIOLYSIS; REDOX PROPERTIES; AQUEOUS-SOLUTION; PORPHIN ISOMER; PORPHYCENES; COORDINATION; CHEMISTRY; COMPLEXES AB One-electron and two-electron oxidations of 2,7,12,17-tetrapropylporphycene (H(2)TPrPc) and its Fe, Co, Ni, Cu, and Sn complexes in CH2Cl2, CCl4, and 2-PrOH solutions have been studied by radiolytic techniques. Formation and decay of intermediates formed upon one-electron oxidation have been followed by kinetic spectrophotometric pulse radiolysis, and the absorption spectra of stable oxidation products have been recorded following gamma-radiolysis. H(2)TPrPc is oxidized to the pi-radical cation and then to the dication, which is stable in aprotic solvents but is transformed to a different product in 2-PrOH. Similar oxidation to the pi-radical cation and then to the dication was observed for the Cu-II, Sn-IV, Co-III, and Fe-III porphycenes. Co-II and Ni-II porphycenes underwent radiolytic oxidation to form stable C-III and Ni-III products. The stability of the latter is in contrast with previous electrochemical observations, and the difference is ascribed to the effect of the axial ligand. C1 NATL INST STAND & TECHNOL,PHYS & CHEM PROPERTIES DIV,GAITHERSBURG,MD 20899. UNIV COLOGNE,INST ORGAN CHEM,D-50939 COLOGNE,GERMANY. RP Guldi, DM (reprint author), UNIV NOTRE DAME,RADIAT LAB,NOTRE DAME,IN 46556, USA. RI Guldi, Dirk/G-1422-2015 NR 35 TC 15 Z9 15 U1 1 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD AUG 8 PY 1996 VL 100 IS 32 BP 13609 EP 13614 DI 10.1021/jp960942j PG 6 WC Chemistry, Physical SC Chemistry GA VB315 UT WOS:A1996VB31500042 ER PT J AU Villalta, PW Howard, CJ AF Villalta, PW Howard, CJ TI Direct kinetics study of the CH3C(O)O-2+NO reaction using chemical ionization mass spectrometry SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID PEROXY-RADICALS; THERMAL-DECOMPOSITION; TEMPERATURE; NITRATE; NO; CHEMISTRY; IONS AB A direct measurement of the CH3C(O)O-2 + NO gas-phase reaction rate coefficient over the temperature range 200-402 K was made using chemical ionization mass spectrometric detection of the CH3C(O)O-2 reactant. A significant temperature dependence was observed, and a temperature dependent expression of k(T) = (8.1 +/- 1.3) x 10(-12) exp{(270 +/- 60)/T} cm(3) molecule(-1) s(-1) was determined. The 298 K rate coefficient, k = (2.0 +/- 0.3) x 10(-11) cm(3) molecule(-1) s(-1), agrees well with results from previous indirect measurements. NO2, CH3, and CO2 were positively identified as products originating from the reaction. The question of whether CH3 and CO2 are direct products of the reaction or result from the thermal decomposition of CH3C(O)O could not be answered, The 298 K rate coefficients for the reactions of SF6-, I-, and O-3(-) with CH3C(O)O-2 were measured to be (7(-2)(+4)) x 10(-10), (9(-5)(+7)) x 10(-10), and greater than or equal to 2 x 10(-10) cm(3) molecule(-1) s(-1), respectively. C1 NOAA,AERON LAB,ENVIRONM RES LABS,BOULDER,CO 80303. OI Villalta, Peter/0000-0002-0067-3083 NR 20 TC 28 Z9 28 U1 2 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD AUG 8 PY 1996 VL 100 IS 32 BP 13624 EP 13628 DI 10.1021/jp9614153 PG 5 WC Chemistry, Physical SC Chemistry GA VB315 UT WOS:A1996VB31500044 ER PT J AU Huang, SX Fischer, DA Gland, JL AF Huang, SX Fischer, DA Gland, JL TI In situ studies of cyclohexylamine dehydrogenation and hydrogenation on the Ni(111) surface SO JOURNAL OF PHYSICAL CHEMISTRY LA English DT Article ID CH3NH2; PT(111); ANILINE AB As part of our program to characterize the primary factors influencing C-N bond activation on Ni surfaces, we have studied the adsorption and reactions of cyclohexylamine (CHA) on the Ni(111) surface in the presence and absence of hydrogen atmospheres. The surface reactions are characterized with temperature-programmed reaction spectroscopy (TPRS) under ultrahigh-vacuum (UHV) conditions and with in situ fluorescence yield (FY) studies on ultrasoft X-ray absorption in H-2 pressures up to 0.01 Torr. The adsorbed configurations of CHA and CHA-derived species are characterized by ultrasoft X-ray spectroscopy. Dehydrogenation is the dominant surface reaction for chemisorbed CHA, resulting in the formation of stable polymeric species. Hydrogen addition results in simultaneous reaction-limited desorption of benzene and ammonia at 380 K as the C-N bond is being cleaved, The yield of the C-N bond activation products increases with H-2 pressure. Single deuteration of both benzene and ammonia is observed at 380 K during experiments in external deuterium. On the basis of these experiments and comparisons with reactivity patterns on the more open Ni(100) surface, we propose that C-N bond activation on the flat Ni(111) surface occurs through hydrogen addition to the C-N bond in an aromatic intermediate adsorbed parallel to surface. The primary polymeric overlayer is stable up to 600 K and decomposes to yield N-2 at 820 K. Above 500 K, carbon in the dehydrogenated intermediate diffuses into the nickel subsurface. External hydrogen decreases the stability of the high-temperature CHA derived polymeric species, yielding predominantly HCN and C2H4 beginning near 450 K. C1 NIST,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899. UNIV MICHIGAN,DEPT CHEM,ANN ARBOR,MI 48109. NR 17 TC 5 Z9 5 U1 4 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0022-3654 J9 J PHYS CHEM-US JI J. Phys. Chem. PD AUG 8 PY 1996 VL 100 IS 32 BP 13629 EP 13635 DI 10.1021/jp951989s PG 7 WC Chemistry, Physical SC Chemistry GA VB315 UT WOS:A1996VB31500045 ER PT J AU Ji, XH vonRosenvinge, EC Johnson, WW Armstrong, RN Gilliland, GL AF Ji, XH vonRosenvinge, EC Johnson, WW Armstrong, RN Gilliland, GL TI Location of a potential transport binding site in a sigma class glutathione transferase by x-ray crystallography SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID S-TRANSFERASE; 3-DIMENSIONAL STRUCTURE; CRYSTAL-STRUCTURES; COMPLEX; RESOLUTION; PROTEIN; THETA AB The crystal structure of the sigma class glutathione transferase from squid digestive gland ire complex with S-(3-iodobenzyl)glutathione reveals a third binding site for the glutathione conjugate besides the two in the active sites of the dimer, The additional binding site is near the crystallographic two-fold axis between the two alpha 4-turn-alpha 5 motifs. The principal binding interactions with the conjugate include specific electrostatic interactions between the peptide and the two subunits and a hydrophobic cavity found across the two-fold axis that accommodates the 3-iodobenzyl group. Thus, two identical, symmetry-related but mutually exclusive binding modes for the third conjugate are observed, The hydrophobic pocket is about 14 Angstrom from the hydroxyl group of Tyr-7 in the active site. This site is a potential transport binding site for hydrophobic molecules or their glutathione conjugates. C1 UNIV MARYLAND, MARYLAND BIOTECHNOL INST, CTR ADV RES BIOTECHNOL, ROCKVILLE, MD 20850 USA. NIST, ROCKVILLE, MD 20850 USA. RI Ji, Xinhua/C-9664-2012 OI Ji, Xinhua/0000-0001-6942-1514 FU NIGMS NIH HHS [GM30910] NR 31 TC 42 Z9 44 U1 0 U2 0 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD AUG 6 PY 1996 VL 93 IS 16 BP 8208 EP 8213 DI 10.1073/pnas.93.16.8208 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA VB325 UT WOS:A1996VB32500011 PM 8710848 ER PT J AU Gandin, CA Schaefer, RJ Rappaz, M AF Gandin, CA Schaefer, RJ Rappaz, M TI Analytical and numerical predictions of dendritic grain envelopes SO ACTA MATERIALIA LA English DT Article ID SOLIDIFICATION PROCESSES AB An analytical model is developed for the prediction of the shape of dendritic grain envelopes during solidification of a metallic alloy in a Bridgman configuration (i.e. constant thermal gradient and cooling rate). The assumptions built into the model allow a direct comparison of the results with those obtained from a previously developed cellular automaton-finite element (CAFE) model. After this comparison, the CAFE model is applied to the study of the extension of a single grain into an open region of liquid after passing a re-entrant corner. The simulation results are compared with experimental observations made on a directionally solidified succinonitrile-acetone alloy. Good agreement is found for the shape of the grain envelopes when varying the orientation of the primary dendrites with respect to the thermal gradient direction, the velocity of the isotherms or the thermal gradient. C1 NIST,GAITHERSBURG,MD 20899. RP Gandin, CA (reprint author), ECOLE POLYTECH FED LAUSANNE,MET PHYS LAB,CH-1015 LAUSANNE,SWITZERLAND. OI GANDIN, Charles-Andre/0000-0002-6270-5407 NR 13 TC 26 Z9 28 U1 0 U2 17 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1359-6454 J9 ACTA MATER JI Acta Mater. PD AUG PY 1996 VL 44 IS 8 BP 3339 EP 3347 DI 10.1016/1359-6454(95)00433-5 PG 9 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA UY539 UT WOS:A1996UY53900029 ER PT J AU Sullivan, J AF Sullivan, J TI Understanding the degrees of freedom concept by computer experiments SO AMERICAN STATISTICIAN LA English DT Article DE chi-square distribution; computer simulation; degrees of freedom AB Numerical experiments on a personal computer are used to illustrate the degrees of freedom concept. Random errors from a known distribution are added to a known model, for example, y(x) = alpha + beta . x, and the least squares fit to the model + error data is computed, The least squares fit produces a new model, y(x) = a + b . x. By definition the sum of squared deviations between the least squares fit model and the data is always less than the sum of squared deviations between the original model and the data. When this process is repeated thousands of times on the computer, using different random errors each time, a pattern emerges, On average the difference between the two sums of squared deviations approaches an integer multiple of the error distribution variance. Furthermore? this integer equals the number of regression parameters in the model. For instance, this is the origin of the two degrees of freedom associated with a linear model. Using the computer it is easy to verify this property for regression models with more than two pa parameters and for different error distributions. The previous degree of freedom property depends only on the variance of the error distribution and use of the least squares method; it does not depend on the detailed shape of the distribution. However. when the normal error distribution with mean = 0 and variance = 1 is used, a connection to another use of the degrees of freedom terminology is found. For a model with M parameters, the normalized frequency distribution of the difference between the two sets of squared deviations is calculated, using 2,000 computer trials, and shown to match the chi-square distribution with M degrees of freedom. RP Sullivan, J (reprint author), US DEPT COMMERCE,NATL ENVIRONM SATELLITE DATA & INFORMAT SERV,OFF RES & APPLICAT,NOAA,WASHINGTON,DC 20233, USA. NR 5 TC 1 Z9 1 U1 0 U2 1 PU AMER STATIST ASSN PI ALEXANDRIA PA 1429 DUKE ST, ALEXANDRIA, VA 22314 SN 0003-1305 J9 AM STAT JI Am. Stat. PD AUG PY 1996 VL 50 IS 3 BP 234 EP 237 DI 10.2307/2684661 PG 4 WC Statistics & Probability SC Mathematics GA VV331 UT WOS:A1996VV33100007 ER PT J AU Gentile, TR Houston, JM Cromer, CL AF Gentile, TR Houston, JM Cromer, CL TI Realization of a scale of absolute spectral response using the national institute of standards and technology high-accuracy cryogenic radiometer SO APPLIED OPTICS LA English DT Article ID QUANTUM EFFICIENCY; OPTICAL-PROPERTIES; SILICON; PHOTODIODES; ELLIPSOMETRY; CONSTANTS; OXIDE; SI AB Using the National Institute of Standards and Technology high-accuracy cryogenic radiometer (HACR), we have realized a scale of absolute spectral response between 406 and 920 nm. The HACR, an electrical-substitution radiometer operating at cryogenic temperatures, achieves a combined relative standard uncertainty of 0.021%. Silicon photodiode light-trapping detectors were calibrated against the HACR with a typical relative standard uncertainty of 0.03% at nine laser wavelengths between 406 and 920 nm. Modeling of the quantum efficiency of these detectors yields their responsivity throughout this range with comparable accuracy. RP Gentile, TR (reprint author), NATL INST STAND & TECHNOL,GAITHERSBURG,MD 20899, USA. NR 29 TC 95 Z9 101 U1 3 U2 10 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD AUG 1 PY 1996 VL 35 IS 22 BP 4392 EP 4403 DI 10.1364/AO.35.004392 PG 12 WC Optics SC Optics GA VA289 UT WOS:A1996VA28900012 PM 21102852 ER PT J AU Nagy, VY Desrosiers, MF AF Nagy, VY Desrosiers, MF TI Complex time dependence of the EPR signal of irradiated L-alpha-alanine SO APPLIED RADIATION AND ISOTOPES LA English DT Article ID DOSIMETRY AB Measurements of the EPR signal amplitude of gamma-irradiated L-alpha-alanine with use of an adjacent reference sample have revealed variations in the signal intensity within hours and days after irradiation. The character of the time dependence of the amplitude varies with dose and the amplitude changes reach 1-1.5%. This observation favors the hypothesis that irradiated alanine contains several paramagnetic centers. Usefulness of adjacent reference samples in alanine dosimetry is also demonstrated. Published by Elsevier Science Ltd RP Nagy, VY (reprint author), NATL INST STAND & TECHNOL,PHYS LAB,IONIZING RADIAT DIV,GAITHERSBURG,MD 20899, USA. NR 11 TC 36 Z9 36 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0969-8043 J9 APPL RADIAT ISOTOPES JI Appl. Radiat. Isot. PD AUG PY 1996 VL 47 IS 8 BP 789 EP 793 DI 10.1016/0969-8043(96)00053-X PG 5 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Chemistry; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA VH992 UT WOS:A1996VH99200015 ER PT J AU Kocan, RM Matta, MB Salazar, SM AF Kocan, RM Matta, MB Salazar, SM TI Toxicity of weathered coal tar for shortnose sturgeon (Acipenser brevirostrum) embryos and larvae SO ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY LA English DT Article ID RAINBOW-TROUT; FISH; BIOAVAILABILITY; ABNORMALITIES; EXPOSURE; ALEVINS; OIL AB Weathered coal tar collected from the Connecticut River near Holyoke, Massachusetts, was toxic to shortnose sturgeon embryos and larvae in whole sediment flow-through and elutriate static-renewal laboratory exposures. Sterile laboratory sand and clean Connecticut River sand, collected upstream from the coal tar deposits, produced no significant difference in toxicity to sturgeon embryos-larvae, while coal tar-contaminated sediment produced over 95% embryo-larval mortality. Hydrocarbon transfer and subsequent toxicity appeared to be via direct contact of the embryos with contaminated sediment, rather than via exposure to soluble hydrocarbons. This conclusion was supported by exposure of embryos and larvae to elutriates (e.g., water soluble extract) of coal-tar sediments, that resulted in embryo and larval mortality at low molecular weight PAH concentrations greater than or equal to 0.47 mg/L, higher than would occur naturally. No decrease in petroleum hydrocarbon concentration was observed in sediments exposed to flowing water for 14 d, supporting the contention that soluble hydrocarbons were not responsible for the observed toxicity in whole sediment exposures under the conditions employed in this study. C1 NOAA,HAZARDOUS MAT RESPONSE & ASSESSMENT DIV,SEATTLE,WA 98115. EVS CONSULTANTS LTD,SEATTLE,WA 98119. RP Kocan, RM (reprint author), UNIV WASHINGTON,SCH FISHERIES,BOX 355100,SEATTLE,WA 98195, USA. NR 19 TC 8 Z9 8 U1 0 U2 7 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0090-4341 J9 ARCH ENVIRON CON TOX JI Arch. Environ. Contam. Toxicol. PD AUG PY 1996 VL 31 IS 2 BP 161 EP 165 PG 5 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA VE112 UT WOS:A1996VE11200001 PM 8785011 ER PT J AU Hill, JE AF Hill, JE TI Service to members is our strategy for success SO ASHRAE JOURNAL-AMERICAN SOCIETY OF HEATING REFRIGERATING AND AIR-CONDITIONING ENGINEERS LA English DT Editorial Material RP Hill, JE (reprint author), NATL INST STAND & TECHNOL,BLDG ENVIRONM DIV,GAITHERSBURG,MD 20899, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC HEAT REFRIG AIR- CONDITIONING ENG INC PI ATLANTA PA 1791 TULLIE CIRCLE NE, ATLANTA, GA 30329 SN 0001-2491 J9 ASHRAE J JI ASHRAE J.-Am. Soc. Heat Refrig. Air-Cond. Eng. PD AUG PY 1996 VL 38 IS 8 BP 46 EP & PG 4 WC Thermodynamics; Construction & Building Technology; Engineering, Mechanical SC Thermodynamics; Construction & Building Technology; Engineering GA VC008 UT WOS:A1996VC00800014 ER PT J AU Morse, JA Blair, WP Dopita, MA Hughes, JP Kirshner, RP Long, KS Raymond, JC Sutherland, RS Winkler, PF AF Morse, JA Blair, WP Dopita, MA Hughes, JP Kirshner, RP Long, KS Raymond, JC Sutherland, RS Winkler, PF TI Hubble Space Telescope observations of oxygen-rich supernova remnants in the Magellanic cloud .1. Narrow-band imaging of N132D in the LMC SO ASTRONOMICAL JOURNAL LA English DT Article ID X-RAY; SHOCK-WAVES; INTERSTELLAR CLOUDS; NOVA REMNANT; YOUNG; EMISSION; SPECTROSCOPY; CASSIOPEIA; KINEMATICS; DISTANCE AB We present Hubble Space Telescope (HST) WFPC2 images of the young, oxygen-rich supernova remnant N132D in the Large Magellanic Cloud in the [O III]lambda 5007, [O II]lambda lambda 3727 and [S II]lambda lambda 6724 emission lines, plus a visible continuum band. The similar to 0.'' 1 resolution of HST allows us to analyze structure within N132D at scales comparable to ground based images of nearby remnants such as Cas A. The oxygen-rich filaments (seen in [O III] and [O II] emission) are easily distinguished from shocked circumstellar clouds (seen in all three emission lines). Characteristic knots sizes and filament widths are similar to 0.'' 2-0.'' 5 (similar to 1.5-4x10(17) cm), at least partially resolved in our images. For the first time, we discern ionization structure within the shocked interstellar clouds and filaments, reminiscent of filaments in galactic SNRs that are thought to arise from recent shock/interstellar cloud encounters where the full cooling and recombination zone has not yet formed throughout the structure. Conversely, there appears to be fairly uniform ionization in the O-rich filaments. We also observe highly ionized, diffuse emission extending all the way around the outer edges of the remnant, as previously seen in ground-based studies. We compare our HST optical emission-line images of N132D to the ROSAT HRI soft X-ray image and find that the X-ray emission is closely traced optically by shocked circumstellar clouds; the O-rich filaments do not appear to be emitting X-rays. The limb-brightened X-ray shell aligns remarkably precisely along the inner edge of the diffuse outer rim. The diffuse emission probably represents ambient molecular gas that is being dissociated and photoionized by high-energy photons originating in the fast SNR shocks. We have used the MAPPINGS II code to model the X-ray producing main blast wave as an similar to 800 km s(-1) shock moving into a circumstellar medium of density N-0 approximate to 3 cm(-3). The preshock ISM density of N-0 approximate to 3 cm(-3) inferred from our shock model agrees with the preshock density estimated from the [O III]lambda 5007 surface brightness in the diffuse outer rim. We also model the [O III]/[S II] emission-line ratios in the photoionized outer rim as a function of distance ahead of the main blast wave using the radiation field produced by fast shocks in the remnant as the ionizing source. According to our models, the ionizing radiation from the similar to 800 km s(-1) main blast wave is not sufficient to generate the observed optical emission from the outer rim precursor. An extra source of EUV photons appears necessary to achieve the observed ionization of the preshock gas. We estimate that EUV photons produced in slower shocks moving into QSF-type clouds around the outer rim can probably contribute enough ionizing photons to achieve the observed ionization. Radiative shocks moving through the O-rich filaments may also be an important source of EUV photons. (C) 1996 American Astronomical Society. C1 UNIV COLORADO,DEPT ASTROPHYS PLANETARY & ATMOSPHER SCI,BOULDER,CO 80309. JOHNS HOPKINS UNIV,DEPT PHYS & ASTRON,BALTIMORE,MD 21218. AUSTRALIAN NATL UNIV,MT STROMLO & SIDING SPRING OBSERV,WESTON,ACT 2611,AUSTRALIA. HARVARD SMITHSONIAN CTR ASTROPHYS,CAMBRIDGE,MA 02138. UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. NATL INST STAND & TECHNOL,BOULDER,CO 80309. MIDDLEBURY COLL,DEPT PHYS,MIDDLEBURY,VT 05753. RP Morse, JA (reprint author), SPACE TELESCOPE SCI INST,3700 SAN MARTIN DR,BALTIMORE,MD 21218, USA. RI Dopita, Michael/P-5413-2014 OI Dopita, Michael/0000-0003-0922-4986 NR 52 TC 50 Z9 50 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0004-6256 J9 ASTRON J JI Astron. J. PD AUG PY 1996 VL 112 IS 2 BP 509 EP 533 DI 10.1086/118031 PG 25 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UZ553 UT WOS:A1996UZ55300014 ER PT J AU Baade, R Kirsch, T Reimers, D Toussaint, F Bennett, PD Brown, A Harper, GM AF Baade, R Kirsch, T Reimers, D Toussaint, F Bennett, PD Brown, A Harper, GM TI The wind outflow of zeta Aurigae: A model revision using Hubble Space Telescope spectra SO ASTROPHYSICAL JOURNAL LA English DT Article DE binaries, eclipsing; circumstellar matter; line, formation; radiative transfer; stars, individual (zeta Aurigae); stars, mass loss; ultraviolet, stars ID RESONANCE LINE FORMATION; AUR/VV CEP SYSTEMS; ULTRAVIOLET-SPECTRA; EXPANDING ENVELOPE; OPTICAL-SPECTRA; BINARY-SYSTEMS; ATMOSPHERES; ECLIPSE; GIANTS AB Using high-resolution spectra taken with the Goddard High-Resolution Spectrograph (GHRS) aboard the Hubble Space Telescope (HST) and with the Inter national Ultraviolet Explorer (IUE) satellite, we reconsider the wind model of zeta Aurigae (K4 Ib + B5 V). The high quality of the HST data permits a critical test of the simplifying assumptions previously used to analyze IUE spectra. We find the line profiles observed with the GHRS show a complex structure, which seems to be inconsistent with the model of a spherically expanding envelope. With detailed line profile calculations, we show that these observations are essentially compatible with a spherical wind outflow in a global sense. However, the distribution of ions must be corrected for ionization effects induced by the B star UV radiation field. We are able to retain the ''classical'' model by introducing some ad hoc modifications and confirm the earlier wind analyses of zeta Aur. We obtain a mass-loss rate of 5 x 10(-9) M, yr(-1) and a terminal wind velocity of 70 km s(-1). The deduced line-broadening velocities clearly decrease with the radial position. The microturbulence is about 20 km s(-1) in the inner envelope (r greater than or similar to 1.2R(sg)) and reaches a minimum of similar to 8 km s(-1) at large distances (r greater than or similar to 25R(sg)). To demonstrate some important effects and to support the reliability of our results, we present a series of model calculations that show the sensitivity of the line formation to the large-scale wind properties. The emission components of strong resonance lines are formed in a region extending up to 50 K star radii and are only slightly dependent upon the global wind geometry. We show that resonance scattering influences considerably the line formation and may distort all analyses that assume pure absorption. C1 UNIV COLORADO, NATL INST STAND & TECHNOL, JOINT INST LAB ASTROPHYS, BOULDER, CO 80309 USA. UNIV COLORADO, CTR ASTROPHYS & SPACE ASTRON, BOULDER, CO 80309 USA. RP Baade, R (reprint author), UNIV HAMBURG, HAMBURGER STERNWARTE, D-21029 HAMBURG, GERMANY. NR 48 TC 23 Z9 23 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD AUG 1 PY 1996 VL 466 IS 2 BP 979 EP 997 DI 10.1086/177569 PN 1 PG 19 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UZ546 UT WOS:A1996UZ54600035 ER PT J AU Steffens, KL Zachariah, MR DuFaux, DP Axelbaum, RL AF Steffens, KL Zachariah, MR DuFaux, DP Axelbaum, RL TI Optical and modeling studies of sodium/halide reactions for the formation of titanium and boron nanoparticles SO CHEMISTRY OF MATERIALS LA English DT Article ID FLAME AB This study focuses on the optical characterization of a method for the formation of nanoscale titanium and boron particles. This versatile method can also be used to form a variety of metals as well as ceramic powders such as TiB2. The gas-phase chemical process, given by (mn)Na + (n)MCl(m) --> (M)(n) + (mn)NaCl, should be generic to many metal chlorides or mixtures of metal chlorides. In this study, either TiCl4 or BCl3 is reacted with Na vapor in a counterflow diffusion flame reactor. After the Cl is stripped from the metal chloride by the Na vapor, nanosize Ti or B particles form and, under certain thermodynamic circumstances, become encased in NaCl, which helps to prevent agglomeration and postflame oxidation. The two-dimensional spatial distribution of Na-2 has been optically interrogated using planar laser-induced fluorescence under various conditions to clarify the influence of concentration and transport on particle formation. Reactant concentration and time available for reaction were found to dramatically influence the reactive flow. Simulations using a counterflow diffusion flame model show that formation of TiB2 likely occurs by gas-phase clustering reactions involving both precursors. The model indicates that experimental results are consistent with the proposed chlorine abstraction mechanism with near-collisional reaction rates. C1 NATL INST STAND & TECHNOL,CHEM SCI & TECHNOL LAB,GAITHERSBURG,MD 20899. WASHINGTON UNIV,DEPT MECH ENGN,ST LOUIS,MO 63130. NR 35 TC 20 Z9 20 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD AUG PY 1996 VL 8 IS 8 BP 1871 EP 1880 DI 10.1021/cm9600844 PG 10 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA VC732 UT WOS:A1996VC73200033 ER PT J AU Jackson, CL McKenna, GB AF Jackson, CL McKenna, GB TI Vitrification and crystallization of organic liquids confined to nanoscale pores SO CHEMISTRY OF MATERIALS LA English DT Article ID GLASS-TRANSITION TEMPERATURE; MOLECULAR LIQUIDS; THIN-FILMS; THERMODYNAMIC PROPERTIES; DIBLOCK COPOLYMERS; POLYMER SURFACES; PHASE-SEPARATION; CARBON NANOTUBES; VOLUME-RECOVERY; POROUS GLASSES AB The effect of finite size on the solidification of o-terphenyl and benzyl alcohol confined in model controlled pore glass (CPG) materials is described. These two organic liquids farm either amorphous glasses or crystalline solids in the bulk upon cooling, depending on the rate of cooling and other factors. The solidification behavior of the liquid in the pores was studied as a function of pore diameter (4-73 nm) chemical surface treatment of the CPG and the degree of pore filling, by differential scanning calorimetry (DSC). We observe that the glass transition, T-g, shifts to a lower temperature as pore size decreases. This shift is independent of the degree of pore filling for both o-terphenyl and benzyl alcohol, suggesting that a reduction in bulk density or a negative pressure effect is not the cause of the observed shift. The crystallization behavior of o-terphenyl and benzyl alcohol is also altered by confinement and strongly depends on the pore size and degree of pore filling. RP NIST, DIV POLYMERS, GAITHERSBURG, MD 20899 USA. RI McKenna, Gregory/O-1134-2013; OI McKenna, Gregory/0000-0002-5676-9930; Jackson, Catheryn/0000-0003-1611-3926 NR 79 TC 203 Z9 208 U1 4 U2 53 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0897-4756 EI 1520-5002 J9 CHEM MATER JI Chem. Mat. PD AUG PY 1996 VL 8 IS 8 BP 2128 EP 2137 DI 10.1021/cm9601188 PG 10 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA VC732 UT WOS:A1996VC73200065 ER PT J AU Spencer, RW Christy, JR Grody, NC AF Spencer, RW Christy, JR Grody, NC TI Analysis of 'examination of ''global atmospheric temperature monitoring with satellite microwave measurements''' - Comment SO CLIMATIC CHANGE LA English DT Article ID RADIOSONDE VALIDATION; SOUNDING UNIT; PRECIPITATION; RADIOMETER; PRECISION; ANOMALIES; MSU AB The potential for residual hydrometeor contamination effects in the global temperature time series produced by Spencer and Christy from MSU channel 2 (MSU2) data has been addressed by Prabhakara et al. (1995, 1996). They use tropical oceanic MSU channel 1 (MSU1) data to estimate the hydrometeor effects on MSU2. We present several lines of evidence to show that their technique greatly overestimates the hydrometeor effects on MSU2. This overestimation is due to the faulty assumption that the hydrometeors that cause MSU1 warming are the same as (or always exist with) the hydrometeors that cause cooling in MSU2. Instead, the hydrometeors responsible for MSU1 warming are liquid phase, while those responsible for MSU2 cooling are large ice particles. Because liquid phase clouds are much more widespread than the large-ice portions of deep convective systems, their method greatly overestimates the areal coverage of contaminated tropical MSU2 data. In addition, we show that the convective screening procedure of Spencer and Christy removes the negative correlation between MSU1 and MSU2 their conclusions rest upon. Radiosonde validation of monthly tropical MSU2 anomalies over the tropical West Pacific also support these conclusions. C1 UNIV ALABAMA,GLOBAL HYDROL & CLIMATE CTR,HUNTSVILLE,AL 35806. NOAA,NATL ENVIRONM SATELLITE DATA & INFORMAT SERV,WASHINGTON,DC 20233. RP Spencer, RW (reprint author), NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,GLOBAL HYDROL & CLIMATE CTR,977 EXPLORER BLVD,HUNTSVILLE,AL 35806, USA. NR 19 TC 8 Z9 8 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0165-0009 J9 CLIMATIC CHANGE JI Clim. Change PD AUG PY 1996 VL 33 IS 4 BP 477 EP 489 DI 10.1007/BF00141700 PG 13 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA VG027 UT WOS:A1996VG02700004 ER PT J AU Margolis, SA Duewer, DL AF Margolis, SA Duewer, DL TI Measurement of ascorbic acid in human plasma and serum: Stability, intralaboratory repeatability, and interlaboratory reproducibility SO CLINICAL CHEMISTRY LA English DT Article DE dithiothreitol; metaphosphoric acid; liquid chromatography; repeatability; reproducibility; bias ID VITAMIN-C; CANCER AB We demonstrate that total ascorbic acid (TAA, the sum of ascorbic acid and dehydroascorbic acid) in properly prepared human plasma is stable at -70 degrees C for at least 6 years when preserved with dithiothreitol, TAA in human plasma or serum preserved with metaphosphoric acid degrades slowly, at the rate of no more than 1% per year, As assessed from our stability data and from data obtained from 23 laboratories over a period of >2 years, the intralaboratory repeatability of TAA measurement is similar to 2 mu mol/L, irrespective of TAA concentration. Nonchromatographic analytical methods involving dinitrophenylhydrazine and o-phenyl-enediamine yield biased results relative to chromatographic methods, Within groups of laboratories that use roughly similar analytical methods, the interlaboratory measurement reproducibility CV for TAA. is 15%. RP Margolis, SA (reprint author), NIST,CHEM SCI & TECHNOL LAB,DIV ANALYT CHEM,BLDG 222,RM B208,GAITHERSBURG,MD 20899, USA. RI Duewer, David/B-7410-2008 FU NCI NIH HHS [CP9-0506] NR 15 TC 47 Z9 48 U1 0 U2 4 PU AMER ASSOC CLINICAL CHEMISTRY PI WASHINGTON PA 2101 L STREET NW, SUITE 202, WASHINGTON, DC 20037-1526 SN 0009-9147 J9 CLIN CHEM JI Clin. Chem. PD AUG PY 1996 VL 42 IS 8 BP 1257 EP 1262 PN 1 PG 6 WC Medical Laboratory Technology SC Medical Laboratory Technology GA VA555 UT WOS:A1996VA55500020 PM 8697586 ER PT J AU Peskin, AP Hardin, GR AF Peskin, AP Hardin, GR TI An object-oriented approach to general purpose fluid dynamics software SO COMPUTERS & CHEMICAL ENGINEERING LA English DT Article AB Our objective is to demonstrate the efficacy of object-oriented programming for the development of scientific and engineering analysis software. We illustrate this through discussion of our application of object-oriented programming to computational fluid dynamics. We have written an object-oriented code in C++ employing the finite element method for the solution of transport-phenomena problems. Our emphasis is chemical engineering applications. The code solves the continuum equations of fluid dynamics, heat transfer and mass transfer with chemical reactions. In principle, the number of chemical reactions is limited only by the computing facilities that are available. New reactions are easily added to the system via the input data to the code. To demonstrate the code, we present original research simulating electroplating into a small pit with a fluid jet traversing the top, as occurs in circuit-board manufacture. We used a fully coupled transient model of the fluid dynamics and electrochemistry, and tracked the growth of the electroplated surface. We describe how this work was facilitated by the use of object-oriented programming. RP Peskin, AP (reprint author), NIST,DIV THERMOPHYS,325 BROADWAY,BOULDER,CO 80303, USA. NR 10 TC 12 Z9 12 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0098-1354 J9 COMPUT CHEM ENG JI Comput. Chem. Eng. PD AUG PY 1996 VL 20 IS 8 BP 1043 EP 1058 DI 10.1016/0098-1354(95)00218-9 PG 16 WC Computer Science, Interdisciplinary Applications; Engineering, Chemical SC Computer Science; Engineering GA UF613 UT WOS:A1996UF61300007 ER PT J AU Reed, RK Stabeno, PJ AF Reed, RK Stabeno, PJ TI On the climatological mean circulation over the eastern Bering Sea shelf SO CONTINENTAL SHELF RESEARCH LA English DT Article ID CURRENTS AB We derive climatological mean summer circulation over the eastern Bering Sea shelf. Geostrophic flow (from CTD data, 1975-1989) and drifter velocities (from satellite-tracked buoys, 1986-1994) were used. The following features are shown: (1) in depths >100 m, a northwestward Row of similar to 4 cm s(-1), which is largely baroclinic; (2) near the 50 m isobath, a flow of similar to 2 cm s(-1), which is only partially baroclinic; and (3) a semi-permanent, convoluted flow of 1-2 cm s(-1), between the 100 and 50 m isobaths, that was not recognized in earlier analyses. Data from current moorings indicate that there is no significant tidal enhancement of net how on the shelf as earlier suggested. This new climatology also shows clearly a divergence of the inflow through Unimak Pass, and it suggests that the shelf salinity distribution is influenced by advection as well as diffusion. Published by Elsevier Science Ltd RP Reed, RK (reprint author), NOAA,PACIFIC MARINE ENVIRONM LAB,7600 SAND POINT WAY NE,SEATTLE,WA 98115, USA. NR 10 TC 19 Z9 19 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0278-4343 J9 CONT SHELF RES JI Cont. Shelf Res. PD AUG PY 1996 VL 16 IS 10 BP 1297 EP 1305 DI 10.1016/0278-4343(95)00067-4 PG 9 WC Oceanography SC Oceanography GA UQ378 UT WOS:A1996UQ37800003 ER PT J AU Kendall, AW Mearns, AJ AF Kendall, AW Mearns, AJ TI Egg and larval development in relation to systematics of Novumbra hubbsi, the Olympic mudminnow SO COPEIA LA English DT Article ID FISHES AB Development of eggs and larvae of reared Novumbra hubbsi is described and compared to that of other esociforms. Early life history and development of all umbrids appears to be similar. Spawning of small clutches of individually adhesive eggs onto roots of aquatic vegetation occurs in springtime. Spawning sites are shallow, low how areas, such as hooded overflow areas adjacent to streams, Spherical, amber eggs of N. hubbsi are about 1.9 mm in diameter and contain multiple oil globules that undergo migrations within the yolk during embryonic development. At hatching, after an incubation period of nearly two weeks at ambient temperatures (10 C), the heavily pigmented larvae are about 5 mm long and relatively undeveloped. The most notable larval feature, until after notochord flexion, is the robust urostyle, which extends almost to the margin of the caudal finfold. Larval development is gradual with no distinct metamorphosis. The juvenile stage is attained at about 20 mm SL. Several developmental features of umbrids indicate a relationship between them and esocids. C1 NATL OCEAN SERV, OFF OCEAN CONSERVAT RESOURCES & ASSESSMENT, SEATTLE, WA 98115 USA. RP Kendall, AW (reprint author), NATL MARINE FISHERIES SERV, ALASKA FISHERIES SCI CTR, NOAA, 7600 SAND POINT WAY NE, BIN C15700, SEATTLE, WA 98115 USA. NR 30 TC 2 Z9 2 U1 0 U2 2 PU AMER SOC ICHTHYOLOGISTS HERPETOLOGISTS PI CHARLESTON PA UNIV CHARLESTON, GRICE MARINE LABORATORY, 205 FORT JOHNSON RD, CHARLESTON, SC 29412 USA SN 0045-8511 J9 COPEIA JI Copeia PD AUG 1 PY 1996 IS 3 BP 684 EP 695 PG 12 WC Zoology SC Zoology GA VB033 UT WOS:A1996VB03300019 ER PT J AU Griffis, RB Kimball, KW AF Griffis, RB Kimball, KW TI Ecosystem approaches to coastal and ocean stewardship SO ECOLOGICAL APPLICATIONS LA English DT Article ID MANAGEMENT; FISHERIES; SUSTAINABILITY; HEALTH C1 NOAA,OFF ASSISTANT SECRETARY,US DEPT COMMERCE,WASHINGTON,DC 20230. RP Griffis, RB (reprint author), NOAA,OFF POLICY & STRATEG PLANNING,US DEPT COMMERCE,14TH & CONSTITUT NW,WASHINGTON,DC 20230, USA. NR 36 TC 32 Z9 32 U1 0 U2 4 PU ECOLOGICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE, NW, STE 400, WASHINGTON, DC 20036 SN 1051-0761 J9 ECOL APPL JI Ecol. Appl. PD AUG PY 1996 VL 6 IS 3 BP 708 EP 712 DI 10.2307/2269467 PG 5 WC Ecology; Environmental Sciences SC Environmental Sciences & Ecology GA UZ412 UT WOS:A1996UZ41200008 ER PT J AU Baker, DJ AF Baker, DJ TI What do ecosystem management and the current budget mean for federally supported environmental research? SO ECOLOGICAL APPLICATIONS LA English DT Article RP Baker, DJ (reprint author), NOAA,US DEPT COMMERCE,14TH & CONSTITUT NW,ROOM 5128,WASHINGTON,DC 20230, USA. NR 1 TC 3 Z9 3 U1 0 U2 2 PU ECOLOGICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE, NW, STE 400, WASHINGTON, DC 20036 SN 1051-0761 J9 ECOL APPL JI Ecol. Appl. PD AUG PY 1996 VL 6 IS 3 BP 712 EP 715 DI 10.2307/2269468 PG 4 WC Ecology; Environmental Sciences SC Environmental Sciences & Ecology GA UZ412 UT WOS:A1996UZ41200009 ER PT J AU MacDonald, DD Carr, RS Calder, FD Long, ER Ingersoll, CG AF MacDonald, DD Carr, RS Calder, FD Long, ER Ingersoll, CG TI Development and evaluation of sediment quality guidelines for Florida coastal waters SO ECOTOXICOLOGY LA English DT Article DE sediment quality guidelines; contaminants; biological effects; marine; estuarine ID CHEMICAL CONCENTRATIONS; CRITERIA; TOXICITY; RANGES; MARINE AB The weight-of-evidence approach to the development of sediment quality guidelines (SQGs) was modified to support the derivation of biological effects-based SQGs for Florida coastal waters. Numerical SQGs were derived for 34 substances, including nine trace metals, 13 individual polycyclic aromatic hydrocarbons (PAHs), three groups of PAHs, total polychlorinated biphenyls (PCBs), seven pesticides and one phthalate ester. For each substance, a threshold effects level (TEL) and a probable effects level (PEL) was calculated. These two values defined three ranges of chemical concentrations, including those that were (1) rarely, (2) occasionally or (3) frequently associated with adverse effects. The SQGs were then evaluated to determine their degree of agreement with other guidelines (an indicator of comparability) and the percent incidence of adverse effects within each concentration range (an indicator of reliability). The guidelines also were used to classify (using a dichotomous system: toxic, with one or more exceedances of the PELs or non-toxic, with no exceedances of the TELs) sediment samples collected from various locations in Florida and the Gulf of Mexico, The accuracy of these predictions was then evaluated using the results of the biological tests that were performed on the same sediment samples. The resultant SQGs were demonstrated to provide practical, reliable and predictive tools for assessing sediment quality in Florida and elsewhere in the southeastern portion of the United States. C1 TEXAS A&M UNIV,NATL BIOL SURVEY,CORPUS CHRISTI,TX 78412. FLORIDA DEPT ENVIRONM PROTECT,TALLAHASSEE,FL 32399. NOAA,COASTAL MONITORING & BIOEFFECTS ASSESSMENT DIV,SEATTLE,WA 98115. NATL BIOL SURVEY,MIDWEST SCI CTR,COLUMBIA,MO 65201. RP MacDonald, DD (reprint author), MACDONALD ENVIRONM SCI LTD,2376 YELLOW POINT RD,RR 3,LADYSMITH,BC V0R 2E0,CANADA. RI Cheng, Jason/A-9296-2010 NR 40 TC 505 Z9 558 U1 12 U2 101 PU CHAPMAN HALL LTD PI LONDON PA 2-6 BOUNDARY ROW, LONDON, ENGLAND SE1 8HN SN 0963-9292 J9 ECOTOXICOLOGY JI Ecotoxicology PD AUG PY 1996 VL 5 IS 4 BP 253 EP 278 DI 10.1007/BF00118995 PG 26 WC Ecology; Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA VH036 UT WOS:A1996VH03600004 PM 24193815 ER PT J AU Kavlock, RJ Daston, GP DeRosa, C FennerCrisp, P Gray, LE Kaattari, S Lucier, G Luster, M Mac, MJ Maczka, C Miller, R Moore, J Rolland, R Scott, G Sheehan, DM Sinks, T Tilson, HA AF Kavlock, RJ Daston, GP DeRosa, C FennerCrisp, P Gray, LE Kaattari, S Lucier, G Luster, M Mac, MJ Maczka, C Miller, R Moore, J Rolland, R Scott, G Sheehan, DM Sinks, T Tilson, HA TI Research needs for the risk assessment of health and environmental effects of endocrine disruptors: A report of the US EPA-sponsored workshop SO ENVIRONMENTAL HEALTH PERSPECTIVES LA English DT Review DE endocrine disruptors; hormones; risk assessment; carcinogenesis; reproductive toxicity; developmental toxicity; immunotoxicity; neurotoxicity; exposure assessment; research needs ID FISH-EATING BIRDS; CONTAMINANT BIOMONITORING PROGRAM; TROUT ONCORHYNCHUS-MYKISS; BREAST-CANCER INCIDENCE; LAWRENCE BELUGA WHALES; MINK MUSTELA-VISON; FRESH-WATER FISH; POLYCHLORINATED-BIPHENYLS; GREAT-LAKES; RAINBOW-TROUT AB The hypothesis has been put forward that humans and wildlife species have suffered adverse health effects after exposure to endocrine-disrupting chemicals. Reported adverse effects include declines in populations, increases in cancers, and reduced reproductive function. The U.S. Environmental Protection Agency sponsored a workshop in April 1995 to bring together interested parties in an effort to identify research gaps related to this hypothesis and to establish priorities for future research activities. Approximately 90 invited participants were organized into work groups developed around the principal reported health effects-carcinogenesis, reproductive toxicity, neurotoxicity, and immunotoxicity--as well as along the risk assessment paradigm--hazard identification, dose-response assessment, exposure assessment, and risk characterization. Attention focused on both ecological and human health effects. In general, the group felt that the hypothesis warranted a concerted research effort to evaluate its validity and that research should focus primarily on effects on development of reproductive capability, on improved exposure assessment, and on the effects of mixtures. This report summarizes the discussions of the work groups and details the recommendations for additional research. C1 PROCTER & GAMBLE CO,MIAMI VALLEY LABS,CINCINNATI,OH. AGCY TOX SUBST & DIS REGISTRY,ATLANTA,GA. US EPA,OFF PREVENT PESTICIDES & TOX SUBST,WASHINGTON,DC 20460. COLL WILLIAM & MARY,VIRGINIA INST MARINE SCI,WILLIAMSBURG,VA. NIEHS,RES TRIANGLE PK,NC 27709. NATL BIOL SERV,WASHINGTON,DC 20240. NATL RES COUNCIL,WASHINGTON,DC 20418. DOW CHEM CO USA,MIDLAND,MI 48674. INST EVALUATING HLTH RISKS,WASHINGTON,DC. WORLD WILDLIFE FUND,WASHINGTON,DC 20037. NATL MARINE FISHERIES SERV,CHARLESTON,SC. US FDA,NATL CTR TOXICOL RES,JEFFERSON,AR 72079. CTR DIS CONTROL & PREVENT,ATLANTA,GA 30341. RP Kavlock, RJ (reprint author), US EPA,NATL HLTH & ENVIRONM EFFECTS RES LAB,RES TRIANGLE PK,NC 27711, USA. OI gray jr, leon earl/0000-0002-1111-4754 NR 193 TC 693 Z9 743 U1 28 U2 217 PU NATL INST ENVIRON HEALTH SCI PI RES TRIANGLE PK PA PO BOX 12233, RES TRIANGLE PK, NC 27709 SN 0091-6765 J9 ENVIRON HEALTH PERSP JI Environ. Health Perspect. PD AUG PY 1996 VL 104 SU 4 BP 715 EP 740 DI 10.2307/3432708 PG 26 WC Environmental Sciences; Public, Environmental & Occupational Health; Toxicology SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Toxicology GA VC106 UT WOS:A1996VC10600002 PM 8880000 ER PT J AU Rakocinski, CF LyczkowskiShultz, J Richardson, SL AF Rakocinski, CF LyczkowskiShultz, J Richardson, SL TI Ichthyoplankton assemblage structure in Mississippi sound as revealed by canonical correspondence analysis SO ESTUARINE COASTAL AND SHELF SCIENCE LA English DT Article DE larval fish assemblages; marine ichthyoplankton; estuarine nursery; Gulf of Mexico ID SHALLOW MARSH HABITATS; MEXICO BARRIER-ISLAND; CAPE FEAR RIVER; SEASONAL FLUCTUATIONS; LARVAL FISHES; NORTHERN GULF; COMMUNITY STRUCTURE; LOUISIANA ESTUARY; EDGE FISHES; ABUNDANCE AB The spatiotemporal dynamics of the ichthyoplankton assemblage structure were investigated in Mississippi Sound, a northern Gulf of Mexico estuary. The study was based on a comprehensive survey constituting 528 collections from 22 stations over 12 months at two tow depths. Important environmental correlates of assemblage structure were identified using canonical correspondence analysis (CCA). A wide taxonomic diversity was encountered during the ichthyoplankton survey, including 152 taxa distributed among 48 families. Strong physical gradients in water temperature, dissolved oxygen and salinity correlated predominantly with ichthyoplankton assemblage structure, and reflected substantial spatiotemporal variation. The CCA results were interpreted in light of adult life-style characteristics. Ecological groups of larvae, as defined by adult life-style characteristics for respective taxa, showed distinctive dispersion patterns in 2-dimensional canonical space. A diverse group of offshore demersal taxa clustered as larvae in a region of CCA space corresponding spatiotemporally with stations located in passes and outside of the Sound during late summer and autumn. Other ecological groups, such as the inshore nektonic and offshore pelagic fishes, were widely dispersed as larvae in canonical space, with member taxa occurring under dissimilar physical conditions. Estuarine embayments in the north-central Gulf of Mexico, like Mississippi Sound, might: be viewed appropriately as landwardmost sections of the wider, highly productive nursery grounds of this region. (C) 1996 Academic Press Limited C1 SE FISHERIES SCI CTR,NATL MARINE FISHERIES SERV,PASCAGOULA,MS 39568. RP Rakocinski, CF (reprint author), GULF COAST RES LAB,POB 7000,OCEAN SPRINGS,MS 39566, USA. RI Rakocinski, Chet/B-1240-2009 OI Rakocinski, Chet/0000-0002-1552-358X NR 41 TC 51 Z9 60 U1 3 U2 10 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON, ENGLAND NW1 7DX SN 0272-7714 J9 ESTUAR COAST SHELF S JI Estuar. Coast. Shelf Sci. PD AUG PY 1996 VL 43 IS 2 BP 237 EP 257 DI 10.1006/ecss.1996.0067 PG 21 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA VC804 UT WOS:A1996VC80400006 ER EF