FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Winton, MJ Russell, SD Gronsky, R AF Winton, MJ Russell, SD Gronsky, R TI Observation of competing etches in chemically etched porous silicon SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID PHOTOLUMINESCENCE; MECHANISM; WAFERS; SI AB Transmission electron microscopy and scanning electron microscopy offer evidence that the purely chemical HF:HNO3:H2O ''stain etch'' used to form light-emitting porous silicon is actually composed of competing etches. A localized etch forms the porous nanostructure by propagation of a discrete reaction interface into the silicon substrate, An amorphous surface layer (SiO2) that is a significant by-product of this etch has been observed and is believed to be a primary efficiency-limiting factor in attempts to fabricate chemically etched porous silicon devices, A destructive etch competes for ions in solution and removes both the porous silicon and the amorphous layers from the surface of the specimen when it becomes dominant, eventually quenching the luminescence properties. C1 USN,COMMAND CONTROL & OCEAN SURVEILLANCE CTR RES DEV,DEV TESTING & EVALUAT DIV,SAN DIEGO,CA 92152. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. RP Winton, MJ (reprint author), UNIV CALIF BERKELEY,DEPT MAT SCI & MINERAL ENGN,BERKELEY,CA 94720, USA. NR 15 TC 11 Z9 11 U1 0 U2 7 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 JUL 1 PY 1997 VL 82 IS 1 BP 436 EP 441 DI 10.1063/1.365833 PG 6 WC Physics, Applied SC Physics GA XG880 UT WOS:A1997XG88000063 ER PT J AU Duxstad, KJ Haller, EE AF Duxstad, KJ Haller, EE TI Schottky contact and thermal stability of Ni on n-type GaN - Comment SO JOURNAL OF APPLIED PHYSICS LA English DT Article AB J. D. Guo et al. [J. Appl. Phys. 80, 1623 (1996)] have studied the thermal stability of Ni on GaN and have deduced by x-ray diffraction measurements that new phases form at the interface between Ni and GaN. This determination, based solely on x-ray diffraction data, is ambiguous, as the peaks assigned to the Ga4Ni3 and Ni-N phases can also be attributed to substrate related x-ray peaks. (C) 1997 American Institute of Physics. RP Duxstad, KJ (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 1 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 JUL 1 PY 1997 VL 82 IS 1 BP 491 EP 492 DI 10.1063/1.365845 PG 2 WC Physics, Applied SC Physics GA XG880 UT WOS:A1997XG88000076 ER PT J AU Ballantyne, B Norris, JC Dodd, DE Klonne, DR Losco, PE Neptun, DA Price, SC Grasso, P AF Ballantyne, B Norris, JC Dodd, DE Klonne, DR Losco, PE Neptun, DA Price, SC Grasso, P TI Short-term and subchronic repeated exposure studies with 5-ethylidene-2-norbornene vapor in the rat SO JOURNAL OF APPLIED TOXICOLOGY LA English DT Article DE ethylidene norbornene; repeated inhalation exposure; rat; thyroid gland AB 5-Ethylidene-2-norbomene (ENB) is an industrial chemical whose physical properties indicate a likelihood for vapor exposure to humans, The potential for target organ or cumulative toxicity was investigated in rats exposed for 6h per day for 9 days over an 11-day period, or 66 or 67 days over 14 weeks; 4-week recovery animals were added to the 14-week study, iMean analytically measured ENB vapor concentrations (+/-SD) were 52 +/- 1.5, 148 +/- 2.3 and 359 +/- 4.2ppm for the 9-day study and 4.9+/-0.14, 24.8 +/- 1.23 and 149 +/- 4.40 ppm for the subchronic study. There were no mortalities, and clinical signs were limited to periocular swelling and/or encrustation, and urogenital area wetness, Body weight gain was decreased in the 9-day 359 ppm females and in the subchronic 24.8 and 149 ppm males, A minimal macrocytic anemia was present in subchronically exposed males, which resolved during the recovery period, In the 9-day study increased liver weight was associated with minimal centrilobular hepatocytomegaly and cytoplasmic basophilia with no degenerative or serum biochemical liver function changes, suggesting an adaptive response, Only relative liver weights were increased in the subchronic 149 ppm males, and no histopathological findings were observed, Principal target organ effects were to the thyroid gland, which showed an exposure concentration-related, but not exposure time-related, depletion of follicular colloid that resolved during the recovery period, together with light microscopic evidence for a hypertrophic and hyperplastic response in the follicular epithelium that resolved more slowly, The thyroid colloid depletion was a graded effect without a clear no-effect concentration, but was not accompanied by any clinical or clear biochemical evidence for thyroid dysfunction, A no-effect concentration of 4.9 ppm was established for the follicular cytological effects. (C) 1997 John Wiley & Sons, Ltd. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37830. MANTECH ENVIRONM TECHNOL INC,DAYTON,OH 45437. RHONE POULENC AG CO,RES TRIANGLE PK,NC 27709. NYCOMED AS,WAYNE,PA 19087. NOVA PHARMACEUT CORP,RES TRIANGLE PK,NC 27709. UNIV SURREY,ROBENS INST HLTH & SAFETY,GUILDFORD GU2 5XH,SURREY,ENGLAND. RP Ballantyne, B (reprint author), UNION CARBIDE CORP,APPL TOXICOL GRP,39 OLD RIDGEBURY RD,DANBURY,CT 06817, USA. NR 15 TC 5 Z9 5 U1 0 U2 0 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0260-437X J9 J APPL TOXICOL JI J. Appl. Toxicol. PD JUL-AUG PY 1997 VL 17 IS 4 BP 197 EP 210 DI 10.1002/(SICI)1099-1263(199707)17:4<197::AID-JAT429>3.0.CO;2-L PG 14 WC Toxicology SC Toxicology GA XR715 UT WOS:A1997XR71500001 PM 9285532 ER PT J AU Buchholz, BA Pawley, NH Vogel, JS Mauthe, RJ AF Buchholz, BA Pawley, NH Vogel, JS Mauthe, RJ TI Pyrethroid decrease in central nervous system from nerve agent pretreatment SO JOURNAL OF APPLIED TOXICOLOGY LA English DT Article DE accelerator mass spectrometry; AMS; pyridostigmine bromide; permethrin; synergism; C-14-label; 'Gulf War syndrome' ID ACCELERATOR MASS-SPECTROMETRY; PERMETHRIN; QUANTIFICATION; PROTECTION; TOXICITY; RATS; AMS AB We studied the effect of pyridostigmine bromide, a nerve agent prophylactic, on the central nervous system (CNS) uptake of [C-14]permethrin, a pyrethroid insecticide, at scaled human-equivalent exposures in rats using accelerator mass spectrometry (AMS). AMS detects C-14 at attomole sensitivities and determines the tissue distribution of C-14-labeled compounds. Pyridostigmine bromide in chow at 7.75 mg kg(-1) per day lowered the CNS tissue levels of permethrin, dosed at 4.75 mu g kg(-1), in the CNS of rats by 30%. These results are inconsistent with hypothesized synergy of such compounds as a precursor to 'Gulf War syndrome'. (C) 1997 John Wiley & Sons, Ltd. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551. RI Buchholz, Bruce/G-1356-2011 NR 22 TC 16 Z9 16 U1 0 U2 2 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0260-437X J9 J APPL TOXICOL JI J. Appl. Toxicol. PD JUL-AUG PY 1997 VL 17 IS 4 BP 231 EP 234 DI 10.1002/(SICI)1099-1263(199707)17:4<231::AID-JAT434>3.0.CO;2-J PG 4 WC Toxicology SC Toxicology GA XR715 UT WOS:A1997XR71500004 PM 9285535 ER PT J AU Adams, JM Faure, H AF Adams, JM Faure, H TI Preliminary vegetation maps of the world since the last glacial maximum: An aid to archaeological understanding SO JOURNAL OF ARCHAEOLOGICAL SCIENCE LA English DT Review DE vegetation; glacial maximum; Holocene; atlas; human ecology ID LATE QUATERNARY VEGETATION; POLLEN RECORD; LATE-PLEISTOCENE; ENVIRONMENTAL-CHANGE; PALYNOLOGICAL EVIDENCE; CLIMATIC CONDITIONS; HOLOCENE CLIMATES; TROPICAL AFRICA; CENTRAL BRAZIL; HIGH-PLAINS AB A set of preliminary, broad-scale vegetation map reconstructions for use by archaeologists and anthropologists is presented here for the world at the last glacial maximum (18,000 rears ago), the early Holocene (8000 years ago), and the mid-Holocene (5000 years ago). For comparison we also give ''present-potential'' maps which may be regarded as approximating the late Holocene vegetation as it would-or might-be without agricultural modification. The maps were produced through consultation with an extensive network of experts and a range of literature and map sources. Accompanying each regional map is a bibliography detailing the principal literature sources of evidence on Late Quaternary palaeovegetation and climates. The maps presented here are not intended as the ''last word'' on the distribution of vegetation at each time slice-they are merely a preliminary attempt at appraisal of current knowledge and opinion. Nevertheless, together with the accompanying citation summary they should provide a valuable and readily accessible sourer of information on current opinion in the Quaternary community. It is also hoped that the maps will themselves act as a catalyst for archaeologists to use their own data to contribute to the broader climatic/palaeovegetational picture. (C) 1997 Press Limited. C1 OAK RIDGE NATL LAB, DIV ENVIRONM SCI, OAK RIDGE, TN 37831 USA. RP Adams, JM (reprint author), UNIV OXFORD, SCH GEOG, 1 MANSFIELD RD, OXFORD OX1 3TB, ENGLAND. NR 282 TC 89 Z9 92 U1 0 U2 7 PU ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0305-4403 J9 J ARCHAEOL SCI JI J. Archaeol. Sci. PD JUL PY 1997 VL 24 IS 7 BP 623 EP 647 DI 10.1006/jasc.1996.0146 PG 25 WC Anthropology; Archaeology; Geosciences, Multidisciplinary SC Anthropology; Archaeology; Geology GA XK015 UT WOS:A1997XK01500005 ER PT J AU Pettersson, B Andersson, A Leitner, T Olsvik, O Uhlen, M Storey, C Black, CM AF Pettersson, B Andersson, A Leitner, T Olsvik, O Uhlen, M Storey, C Black, CM TI Evolutionary relationships among members of the genus Chlamydia based on 16S ribosomal DNA analysis SO JOURNAL OF BACTERIOLOGY LA English DT Article ID PNEUMONIAE STRAIN TWAR; PLASMID DNA; RNA; SEQUENCE; INFECTION; PSITTACI; CULTURE; ORIGIN AB Nucleotide sequences from strains of the four species currently in the genus Chlamydia, C. pecorum, C. pneumoniae, C. psittaci, and C. trachomatis were investigated. In vitro-amplified RNA genes of the ribosomal small subunit from 30 strains of C. pneumoniae and C. pecorum were subjected to solid-phase DNA sequencing of both strands. The human isolates of C. pneumoniae differed in only one position in the 16S rRNA gene, indicating genetic homogeneity among these strains. Interestingly, horse isolate N16 of C. pneumoniae was found to be closely related to the human isolates of this species, with a 98.9% nucleotide similarity between their 16S rRNA sequences. The type strain and koala isolates of C. pecorum were also found to be very similar to each other, possessing two different 16S rRNA sequences with only one-nucleotide difference. Furthermore, the C. pecorum strains truncated the 16S rRNA molecule by one nucleotide compared to the molecules of the other chlamydial species. This truncation was found to result in loss of a unilaterally bulged nucleotide, an attribute present in all other eubacteria. The phylogenetic structure of the genus Chlamydia was determined by analysis of 16S rRNA sequences. All phylogenetic trees revealed a distinct line of descent of the family Chlamydiaceae built of two main clusters which we denote the C. pneumoniae cluster and the C. psittaci cluster. The clusters were verified by bootstrap analysis of the trees and signature nucleotide analysis. The former cluster contained the human isolates of C. pneumoniae and equine strain N16. The latter cluster consisted of C. psittaci, C. pecorum, and C. trachomatis. The members of the C. pneumoniae cluster showed tight clustering and strain N16 is likely to be a subspecies of C. pneumoniae since these strains also share some antigenic cross-reactivity and clustering of major outer membrane protein gene sequences. C. psittaci and strain N16 branched early out of the respective cluster, and interestingly, their inclusion bodies do not stain with iodine. Furthermore, they also share less reliable features like normal elementary body morphology and plasmid content. Therefore, the branching order presented here is very likely a true reflection of evolution, with strain N16 of the species C. pneumoniae and C. psittaci forming early branches of their respective cluster and with C. trachomatis being the more recently evolved species within the genus Chlamydia. C1 CTR DIS CONTROL & PREVENT,NATL CTR INFECT DIS,ATLANTA,GA 30333. ROYAL INST TECHNOL,DEPT BIOCHEM & BIOTECHNOL,S-10044 STOCKHOLM,SWEDEN. LOS ALAMOS NATL LAB,GRP T10,LOS ALAMOS,NM. UNIV TROMSO,SCH MED,DEPT MED MICROBIOL,TROMSO,NORWAY. UNIV LEEDS,DEPT MICROBIOL,LEEDS LS2 9JT,W YORKSHIRE,ENGLAND. NR 47 TC 26 Z9 26 U1 0 U2 0 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 SN 0021-9193 J9 J BACTERIOL JI J. Bacteriol. PD JUL PY 1997 VL 179 IS 13 BP 4195 EP 4205 PG 11 WC Microbiology SC Microbiology GA XJ207 UT WOS:A1997XJ20700015 PM 9209033 ER PT J AU Pinkart, HC White, DC AF Pinkart, HC White, DC TI Phospholipid biosynthesis and solvent tolerance in Pseudomonas putida strains SO JOURNAL OF BACTERIOLOGY LA English DT Article ID ESCHERICHIA-COLI; FATTY-ACIDS; ZYMOMONAS-MOBILIS; LIPID-COMPOSITION; MEMBRANE-LIPIDS; CELL-DIVISION; BACTERIUM; TOLUENE; ETHANOL; HYDROCARBONS AB The role of the cell envelope in the solvent tolerance mechanisms of Pseudomonas putida was investigated. The responses of a solvent-tolerant strain, P. putida Idaho, and a solvent-sensitive strain, P. putida MW1200, were examined in terms of phospholipid content and composition and of phospholipid biosynthetic rate following exposure to a nonmetabolizable solvent, o-xylene. Following o-xylene exposure, P. putida MW1200 exhibited a decrease in total phospholipid content. In contrast, P. putida Idaho demonstrated an increase in phospholipid content 1 to 6 h after exposure. Analysis of phospholipid biosynthesis showed P. putida Idaho to have a higher basal rate of phospholipid synthesis than MW1200. This rate increased significantly following exposure to xylene. Both strains showed little significant turnover of phospholipid in the absence of xylene. In the presence of xylene, both strains showed increased phospholipid turnover. The rate of turnover was significantly greater in P. putida Idaho than in P. putida MW1200. These results suggest that P. putida Idaho has a greater ability than the solvent-sensitive strain MW1200 to repair damaged membranes through efficient turnover and increased phospholipid biosynthesis. C1 UNIV TENNESSEE,CTR ENVIRONM BIOTECHNOL,KNOXVILLE,TN 37932. UNIV TENNESSEE,DEPT MICROBIOL,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,DIV ENVIRONM SCI,OAK RIDGE,TN 37831. NR 48 TC 71 Z9 75 U1 1 U2 13 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 SN 0021-9193 J9 J BACTERIOL JI J. Bacteriol. PD JUL PY 1997 VL 179 IS 13 BP 4219 EP 4226 PG 8 WC Microbiology SC Microbiology GA XJ207 UT WOS:A1997XJ20700018 PM 9209036 ER PT J AU IshaugRiley, SL Crane, GM Gurlek, A Miller, MJ Yasko, AW Yaszemski, MJ Mikos, AG AF IshaugRiley, SL Crane, GM Gurlek, A Miller, MJ Yasko, AW Yaszemski, MJ Mikos, AG TI Ectopic bone formation by marrow stromal osteoblast transplantation using poly(DL-lactic-co-glycolic acid) foams implanted into the rat mesentery SO JOURNAL OF BIOMEDICAL MATERIALS RESEARCH LA English DT Article; Proceedings Paper CT 23rd Annual Meeting of the Society-for-Biomaterials CY APR 30-MAY 04, 1997 CL NEW ORLEANS, LA SP Soc Biomat DE poly(alpha-hydroxy esters); biodegradable polymer scaffolds; osteoblast transplantation; boye tissue engineering ID HEPATOCYTE TRANSPLANTATION; BIODEGRADABLE POLYMERS; POLY(L-LACTIC ACID); DIFFERENTIATION; CELLS AB Porous biodegradable poly(DL-lactic-co-glycolic acid) foams were seeded with rat marrow stromal cells and implanted into the rat mesentery to investigate in vivo bone formation at an ectopic site. Cells were seeded at a density of 6.83 x 10(5) cells/cm(2) onto polymer foams having pore sizes ranging from either 150 to 300 or 500 to 710 mu m and cultured for 7 days in vitro prior to implantation. The polymer/cell constructs were harvested after 1, 7, 28, or 49 days in vivo and processed for histology and gel permeation chromatography. Visual observation of hematoxylin and eosin-stained sections and von Kossa-stained sections revealed the formation of mineralized bonelike tissue in the constructs within 7 days postimplantation. Ingrowth of vascular tissue was also found adjacent to the islands of bone, supplying the necessary metabolic requirements to the newly formed tissue. Mineralization and bone tissue formation were investigated by histomorphometry. The average penetration depth of mineralized tissue in the construct ranged from 190 +/- 50 mu m for foams with 500-710-mu m pores to 370 +/- 160 mu m for foams with 150-300-mu m pores after 49 days in vivo. The mineralized bone volume per surface area and total bone volume per surface area had maximal values of 0.028 +/- 0.021 mm (500-710-mu m pore size, day 28) and 0.038 +/- 0.024 mm (150-300-mu m, day 28), respectively. As much as 11% of the foam volume penetrated by bone tissue was filled with mineralized tissue. No significant trends over time were observed for any of the measured values (penetration depth, bone volume/surface area, or percent mineralized bone volume). These results suggest the feasibility of bone formation by osteoblast transplantation in an orthotopic site where not only bone formation from transplanted cells but also ingrowth from adjacent bone may occur. (C) 1997 John Wiley & Sons, Inc. C1 RICE UNIV,INST BIOSCI & BIOENGN,COX LAB BIOMED ENGN,HOUSTON,TX 77251. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. UNIV TEXAS,MD ANDERSON CANC CTR,DEPT PLAST & RECONSTRUCT SURG,HOUSTON,TX 77030. UNIV TEXAS,MD ANDERSON CANC CTR,DEPT ORTHOPAED SURG,HOUSTON,TX 77030. MAYO CLIN & MAYO FDN,DEPT ORTHOPED SURG,ROCHESTER,MN 55905. OI Crane, Genevieve/0000-0001-9274-0214 FU NIAMS NIH HHS [R29-AR42639] NR 20 TC 198 Z9 212 U1 1 U2 7 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0021-9304 J9 J BIOMED MATER RES JI J. Biomed. Mater. Res. PD JUL PY 1997 VL 36 IS 1 BP 1 EP 8 DI 10.1002/(SICI)1097-4636(199707)36:1<1::AID-JBM1>3.0.CO;2-P PG 8 WC Engineering, Biomedical; Materials Science, Biomaterials SC Engineering; Materials Science GA XG354 UT WOS:A1997XG35400001 PM 9212383 ER PT J AU Lobree, LJ Aylor, AW Reimer, JA Bell, AT AF Lobree, LJ Aylor, AW Reimer, JA Bell, AT TI Role of cyanide species in the reduction of NO by CH4 over Co-ZSM-5 SO JOURNAL OF CATALYSIS LA English DT Article ID COORDINATED NITRIC-OXIDE; SELECTIVE REDUCTION; MIGRATORY INSERTION; HYDROCARBONS; MECHANISM; COMPLEXES; CU-ZSM-5 AB In situ infrared observation during the reduction of NO by CH4 over Co-ZSM-5 reveals the presence of CN species. The reactivity of these species has been probed by exposing them to NO2, O-2, or NO while monitoring their rate of disappearance. In a complementary set of experiments, mass spectrometry was used to identify the reaction products as N-2 and CO2. At 450 degrees C the rate coefficients for the consumption of CN are 8.5 x 10(-5), 1.9 x 10(-6), and 3.3 x 10(-7) s(-1) ppm(-1) for reaction in NO2, O-2, and NO, respectively. The reactivity of CN is sufficiently high for these species to be considered reaction intermediates in the formation of N-2 and CO2 during the reduction of NO by CH4 in the presence of O-2. (C) 1997 Academic Press. C1 UNIV CALIF BERKELEY,DEPT CHEM ENGN,BERKELEY,CA 94720. RP Lobree, LJ (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,CTR ADV MAT,BERKELEY,CA 94720, USA. OI Bell, Alexis/0000-0002-5738-4645 NR 16 TC 88 Z9 89 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 0021-9517 J9 J CATAL JI J. Catal. PD JUL 1 PY 1997 VL 169 IS 1 BP 188 EP 193 DI 10.1006/jcat.1997.1699 PG 6 WC Chemistry, Physical; Engineering, Chemical SC Chemistry; Engineering GA XL779 UT WOS:A1997XL77900019 ER PT J AU Mullica, DF Leschnitzer, DH Sappenfield, EL AF Mullica, DF Leschnitzer, DH Sappenfield, EL TI X-ray crystal structure of cis-H(Ph3Si)Pt[Ph2P(CH2)(4)PPh2]center dot 0.5 C6H6 SO JOURNAL OF CHEMICAL CRYSTALLOGRAPHY LA English DT Article DE organometallic complex; chelating complex; diphosphine platinum(II); structure analysis; X-ray crystallography ID MOLECULAR-STRUCTURE; COMPLEXES AB The title compound, cis-hydrido(triphenylsilyl)-1,4-butanediyl-bis-(diphenylphosphine)pla num(II) (I), crystallizes in the monoclinic space group P2(1)/n (No. 14) with a = 9.472(4), b = 16.924(5), c = 25.799(4) Angstrom, beta = 91.29(3)degrees and Z = 4. The structure was served using the direct methods and refined by the full-matrix least-squares procedure to yield residuals of R = 0.024 and R-w = 0.025 based on 4160 unique reflections. The square-planar geometry about the Pt atom is angularly distorted with P(1)-Pt-P(2) and Si-Pt-P(2) angles of 103.5(1) and 102.1(1)degrees, respectively. The Pt-P(1) bond is longer than the Pt-P(2) bond due to the trans influence of the SiPh3 group. Distortion due to steric bulk of the ligands is accommodated by the opening of the tetrahedral angles at the silicon and phosphorous atoms. C1 LOS ALAMOS NATL LAB,DEPT CHEM,LOS ALAMOS,NM 87545. RP Mullica, DF (reprint author), BAYLOR UNIV,DEPT CHEM,POB 97348,WACO,TX 76798, USA. RI G, Neela/H-3016-2014 NR 17 TC 6 Z9 6 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 1074-1542 J9 J CHEM CRYSTALLOGR JI J. Chem. Crystallogr. PD JUL PY 1997 VL 27 IS 7 BP 435 EP 439 PG 5 WC Crystallography; Spectroscopy SC Crystallography; Spectroscopy GA XX850 UT WOS:A1997XX85000009 ER PT J AU Wu, HB Wang, LS AF Wu, HB Wang, LS TI A study of nickel monoxide (NiO), nickel dioxide (ONiO), and Ni(O-2) complex by anion photoelectron spectroscopy SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID TRANSITION-METAL OXIDES; NEGATIVE-IONS; GROUND-STATE; MOLECULE; ENERGIES; CUO2 AB We report the first anion photoelectron spectroscopic study of nickel monoxide (NiO), nickel dioxide (ONiO), and nickel-O-2 complex, Ni(O-2). The adiabatic electron affinity (EA) of NiO is measured to be 1.46 (2) eV. Five low-lying electronic excited states (A (3) Pi, a (1) Delta, B (3) Phi, b (1) Sigma(+), c (1) Pi) are observed for NiO at 0.43 (4), 0.94 (4), 1.24 (3), 1.80 (10), and 2.38 (10) eV above the ground state, respectively. Two isomers are observed for NiO2, i.e., the linear ONiO dioxide and the Ni(O-2) complex. The dioxide has a high EA of 3.05 (1) eV while the Ni(O-2) complex has a rather low EA of 0.82 (3) eV. Two low-lying excited states are observed for ONiO at 0.40 (2) and 0.77 (3) eV above the ground state, respectively. The vibrational frequency of the nu(1) mode of the ground state ONiO (X (3) Sigma(g)(-)) is measured to be 750 (30) cm(-1). The excited states of the Ni(O-2) complex give broad photodetachment features starting at about 1.1 eV above the ground state. Information about the electronic structures of the nickel oxide species and chemical bonding between Ni and O and O-2 is obtained and discussed. (C) 1997 American Institute of Physics. C1 PACIFIC NW LAB, ENVIRONM MOL SCI LAB, RICHLAND, WA 99352 USA. RP Wu, HB (reprint author), WASHINGTON STATE UNIV, DEPT PHYS, RICHLAND, WA 99352 USA. NR 36 TC 78 Z9 78 U1 3 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 JUL 1 PY 1997 VL 107 IS 1 BP 16 EP 21 DI 10.1063/1.474362 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA XG244 UT WOS:A1997XG24400002 ER PT J AU Davis, MJ AF Davis, MJ TI Chaotic dynamics and approximate semiclassical quantization: Assigning highly excited vibrational eigenstates SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID BOUND-STATES; QUANTUM; MOLECULES; SYSTEMS; MANIFESTATIONS; COMPUTATION; EIGENVALUES; OSCILLATOR; RESONANCES; TRANSPORT AB The classical dynamics of highly chaotic vibrational dynamics is studied via the nature of resonance zones. It is demonstrated that the flow into and out of the resonance zones is complicated with some trajectories spending less than one period outside before reentering, referred to here as ''virtual recrossing.'' Despite the strong chaos, an approximate semiclassical quantization method based on the resonance zone structure can be used to generate eigenvalues to within a few percent of the quantum values well into the chaotic regime. The semiclassical quantization allows for the assignment of highly excited, strongly mixed vibrational eigenstates. (C) 1997 American Institute of Physics. RP Davis, MJ (reprint author), ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439, USA. NR 39 TC 17 Z9 17 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 JUL 1 PY 1997 VL 107 IS 1 BP 106 EP 118 DI 10.1063/1.475136 PG 13 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA XG244 UT WOS:A1997XG24400013 ER PT J AU OShea, SF Dubey, GS Rasaiah, JC AF OShea, SF Dubey, GS Rasaiah, JC TI Phase transitions of quadrupolar fluids SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID THERMODYNAMIC PERTURBATION-THEORY; DIPOLAR HARD-SPHERES; SIMPLE POLAR FLUIDS; MONTE-CARLO; COEXISTENCE; ENSEMBLE; LIQUID AB Gibbs ensemble simulations are reported for Lennard-Jones particles with embedded quadrupoles of strength Q*=Q/(epsilon sigma(5))(1/2)=2.0 where epsilon and sigma are the Lennard-Jones parameters. Calculations revealing the effect of the dispersive forces on the liquid-vapor coexistence were carried out by scaling the attractive r(-6) term in the Lennard-Jones pair potential by a factor lambda ranging from 0 to 1. Liquid-vapor coexistence is observed for all values of lambda including lambda = 0 for Q* = 2.0, unlike the corresponding dipolar fluid studied by van Leeuwen and Smit et al. [Phys. Rev. Lett. 71, 3991 (1993)] which showed no phase transition below lambda = 0.35 when the reduced dipole moment mu* = 2.0. The simulation data are analyzed to estimate the critical properties of the quadrupolar fluid and their dependence on the strength lambda of the dispersive force. The critical temperature and pressure show a clear quadratic dependence on lambda, while the density is less confidently identified as being linear in lambda. The compressibility is roughly linear in lambda. (C) 1997 American Institute of Physics. C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. CUNY HUNTER COLL,DEPT PHYS & ASTRON,NEW YORK,NY 10021. UNIV MAINE,DEPT CHEM,ORONO,ME 04469. RP OShea, SF (reprint author), UNIV LETHBRIDGE,DEPT CHEM,LETHBRIDGE,AB T1K 3M4,CANADA. RI O'Shea, Seamus/H-4590-2013 OI O'Shea, Seamus/0000-0002-5948-958X NR 19 TC 13 Z9 13 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 JUL 1 PY 1997 VL 107 IS 1 BP 237 EP 242 DI 10.1063/1.474370 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA XG244 UT WOS:A1997XG24400025 ER PT J AU Zhang, Y Wang, WC AF Zhang, Y Wang, WC TI Model-simulated northern winter cyclone and anticyclone activity under a greenhouse warming scenario SO JOURNAL OF CLIMATE LA English DT Article ID GENERAL-CIRCULATION MODEL; LAYER OCEAN MODEL; STORM-TRACKS; CLIMATE SENSITIVITY; EFFECTIVE CO2; CYCLOGENESIS; GASES; RESOLUTION; DEPENDENCE; INADEQUACY AB Two 100-yr equilibrium simulations from the NCAR Community Climate Model coupled to a nondynamic slab ocean are used to investigate the activity of northern winter extratropical cyclones and anticyclones under a greenhouse warming scenario. The first simulation uses the 1990 observed CO2, CH4, N2O, CFC-11, and CFC-12 concentrations, and the second adopts the year 2050 concentrations according to the Intergovernmental Panel on Climate Change business-as-usual scenario. Variables that describe the characteristic properties of the cyclone-scale eddies, such as surface cyclone and anticyclone frequency and the bandpassed root-mean-square of 500-hPa geopotential height, along with the Eady growth rate maximum, form a framework for the analysis of the cyclone and anticyclone activity. Objective criteria are developed for identifying cyclone and anticyclone occurrences based on the 1000-hPa geopotential height and vorticity fields and tested using ECMWF analyses. The potential changes of the eddy activity under the greenhouse warming climate are then examined. Results indicate that the activity of cyclone-scale eddies decreases under the greenhouse warming scenario. This is not only reflected in the surface cyclone and anticyclone frequency and in the bandpassed rms of 500-hPa geopotential height, but is also discerned from the Eady growth rate maximum. Based on the analysis, three different physical mechanisms responsible far the decreased eddy activity are discussed: 1) a decrease of the extratropical meridional temperature gradient from the surface to the midtroposphere, 2) a reduction in the land-sea thermal contrast in the east coastal regions of the Asian and North American continents, and 3) an increase in the eddy meridional latent heat fluxes. Uncertainties in the results related to the limitations of the model and the model equilibrium simulations are discussed. C1 SUNY ALBANY,ATMOSPHER SCI RES CTR,ALBANY,CA. RP Zhang, Y (reprint author), LAWRENCE LIVERMORE NATL LAB,PROGRAM CLIMATE MODEL DIAG & INTERCOMPARISON,LIVERMORE,CA 94550, USA. NR 45 TC 56 Z9 56 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 JUL PY 1997 VL 10 IS 7 BP 1616 EP 1634 DI 10.1175/1520-0442(1997)010<1616:MSNWCA>2.0.CO;2 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA XP278 UT WOS:A1997XP27800010 ER PT J AU Gaffen, DJ Rosen, RD Salstein, DA Boyle, JS AF Gaffen, DJ Rosen, RD Salstein, DA Boyle, JS TI Evaluation of tropospheric water vapor simulations from the atmospheric model intercomparison project SO JOURNAL OF CLIMATE LA English DT Article ID GENERAL-CIRCULATION MODEL; HORIZONTAL RESOLUTION; SURFACE-TEMPERATURE; PRECIPITABLE WATER; CLIMATE SIMULATION; SEASONAL-VARIATION; ECMWF MODEL; PARAMETERIZATION; SENSITIVITY; SCHEME AB Simulations of humidity from 28 general circulation models for the period 1979-88 from the Atmospheric Model Intercomparison Project are compared with observations from radiosondes over North America and the globe and with satellite microwave observations over the Pacific basin. The simulations of decadal mean values of precipitable water (W) integrated over each of these regions tend to be less moist than the real atmosphere in all three cases; the median model values are approximately 5% less than the observed values. The spread among the simulations is larger over regions of high terrain, which suggests that differences in methods of resolving topographic features are important. The mean elevation of the North American continent is substantially higher in the models than is observed, which may contribute to the overall dry bias of the models over that area. The authors do not find a clear association between the mean topography of a model and its mean W simulation, however, which suggests that the bias over land is not purely a matter of orography. The seasonal cycle of W is reasonably well simulated by the models, although over North America they have a tendency to become moister more quickly in the spring than is observed. The interannual component of the variability of W is nor well captured by the models over North America. Globally, the simulated W values show a signal correlated with the Southern Oscillation index but the observations do not. This discrepancy may be related to deficiencies in the radiosonde network, which does not sample the tropical ocean regions well. Overall, the interannual variability of W as well as its climatology and mean seasonal cycle, are better described by the median of the 28 simulations than by individual members of the ensemble. Tests to learn whether simulated precipitable water, evaporation, and precipitation values may be related to aspects of model formulation yield few clear signals, although the authors find, for example, a tendency for the few models that predict boundary layer depth to have large values of evaporation and precipitation. Controlled experiments, in which aspects of model architecture are systematically varied within individual models, may be necessary to elucidate whether and how model characteristics influence simulations. C1 ATMOSPHER & ENVIRONM RES INC,CAMBRIDGE,MA 02139. LAWRENCE LIVERMORE NATL LAB,PROGRAM CLIMATE MODEL DIAG & INTERCOMPARISON,LIVERMORE,CA. RP Gaffen, DJ (reprint author), NOAA,REAR,ENVIRONM RES LABS,AIR RESOURCES LAB,1315 E WEST HIGHWAY,SILVER SPRING,MD 20910, USA. NR 56 TC 17 Z9 17 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 JUL PY 1997 VL 10 IS 7 BP 1648 EP 1661 DI 10.1175/1520-0442(1997)010<1648:EOTWVS>2.0.CO;2 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA XP278 UT WOS:A1997XP27800012 ER PT J AU He, XY Doolen, G AF He, XY Doolen, G TI Lattice Boltzmann method on curvilinear coordinates system: Flow around a circular cylinder SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article ID IMPULSIVELY STARTED CYLINDER; NAVIER-STOKES EQUATION; VISCOUS-FLOW; PARTICULATE SUSPENSIONS; NUMERICAL SIMULATIONS; UNIFORM TRANSLATION; MAIN FEATURES; GAS AUTOMATA; EARLY STAGE; WAKE AB Using an interpolation-based strategy, the lattice Boltzmann method is extended to apply to general curvilinear coordinate systems. As an example, a cylindrical coordinate system is used to simulate two-dimensional flow around a circular cylinder. Numerical simulations are carried out for impulsive initial conditions with Reynolds numbers up to 10(4). The agreement of our results with previous computational and experimental results is satisfactory. Compared with previous lattice Boltzmann simulations of the same problem, our new approach greatly enhances the computational efficiency. (C) 1997 Academic Press. C1 LOS ALAMOS NATL LAB,DIV THEORET,GRP T13,LOS ALAMOS,NM 87545. RP He, XY (reprint author), LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES,MS-B258,LOS ALAMOS,NM 87545, USA. NR 33 TC 186 Z9 199 U1 4 U2 29 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0021-9991 J9 J COMPUT PHYS JI J. Comput. Phys. PD JUL 1 PY 1997 VL 134 IS 2 BP 306 EP 315 DI 10.1006/jcph.1997.5709 PG 10 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA XH842 UT WOS:A1997XH84200009 ER PT J AU Shan, C Javandel, I AF Shan, C Javandel, I TI Analytical solutions for solute transport in a vertical aquifer section SO JOURNAL OF CONTAMINANT HYDROLOGY LA English DT Article DE analytical solutions; transport; dissolved chemicals; aquifer section ID DENSE CHLORINATED SOLVENTS; SATURATED POROUS-MEDIA; CONTAMINANT TRANSPORT; DISSOLUTION; GROUNDWATER; POOLS; DISPERSION; BOUNDARY; SYSTEMS; MODEL AB Analytical solutions are developed for modeling solute transport in a vertical section of a homogeneous aquifer with steady uniform groundwater flow. The source is assumed to be located at the top (or the bottom) of the aquifer, and the initial concentration is assumed to be zero everywhere in the aquifer. Both constant-flux and constant-concentration sources are treated. For cases of a constant-flux source, we present exact analytical solutions considering the following transport mechanisms: advection in the horizontal direction, dispersions in both horizontal and vertical directions, adsorption, and biodegradation. For cases of a constant-concentration source, we present simplified analytical solutions by neglecting dispersion in the horizontal direction. For both kinds of sources, the solutions for aquifers with a relatively large or small thickness are presented and compared. The solutions for the two different source conditions are also compared for similar cases. The comparisons indicate that simpler solutions, used in appropriate cases, can give the same results as those given by more complex solutions. Example calculations are given to show the movement of the contamination front, the steady-state concentration profiles, and the applications to determine dispersivities. The analytical solutions developed in this study can be useful in site characterization, groundwater monitoring, and remediation. Published by Elsevier Science B.V. RP Shan, C (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV EARTH SCI,BERKELEY,CA 94720, USA. NR 29 TC 11 Z9 11 U1 0 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-7722 J9 J CONTAM HYDROL JI J. Contam. Hydrol. PD JUL PY 1997 VL 27 IS 1-2 BP 63 EP 82 DI 10.1016/S0169-7722(96)00045-9 PG 20 WC Environmental Sciences; Geosciences, Multidisciplinary; Water Resources SC Environmental Sciences & Ecology; Geology; Water Resources GA XK435 UT WOS:A1997XK43500004 ER PT J AU Grein, CH Faurie, JP Bousquet, V Tournie, E Benedek, R delaRubia, T AF Grein, CH Faurie, JP Bousquet, V Tournie, E Benedek, R delaRubia, T TI Simulations of ZnSe/GaAs heteroepitaxial growth SO JOURNAL OF CRYSTAL GROWTH LA English DT Article DE computer simulation; epitaxial growth ID SCANNING-TUNNELING-MICROSCOPY; TOTAL-ENERGY CALCULATIONS; MOLECULAR-BEAM EPITAXY; MONTE-CARLO; DISLOCATION-STRUCTURE; ELECTRONIC-STRUCTURE; SURFACE; DYNAMICS; ZNSE(100); GAAS(001) AB The epitaxial growth of ZnSe on GaAs(0 0 1) is simulated by employing a hybrid approach based on molecular dynamics to describe the initial kinetic behavior of deposited adatoms and Monte Carlo displacements to account for subsequent equilibration. Stillinger-Weber potentials are employed to describe interatomic interactions. This method is well-suited to describe initial nucleation and growth. Results for a variety of growth temperature and interface structures are presented. C1 CNRS SOPHIA ANTIPOLIS,CTR RECH HEREROEPITAX & APPLICAT,F-06560 VALBONNE,FRANCE. ARGONNE NATL LAB,JOURNAL APPL PHYS,ARGONNE,IL 60439. LAWRENCE LIVERMORE NATL LAB,DIV CHEM & MAT SCI,LIVERMORE,CA 94550. RP Grein, CH (reprint author), UNIV ILLINOIS,DEPT PHYS,CHICAGO,IL 60607, USA. RI Tournie, Eric/F-8327-2015 OI Tournie, Eric/0000-0002-8177-0810 NR 40 TC 25 Z9 26 U1 0 U2 8 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 JUL PY 1997 VL 178 IS 3 BP 258 EP 267 DI 10.1016/S0022-0248(96)01193-1 PG 10 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA XK669 UT WOS:A1997XK66900009 ER PT J AU Maynes, D Klewicki, J McMurtry, P Robey, H AF Maynes, D Klewicki, J McMurtry, P Robey, H TI Hydrodynamic scalings in the rapid growth of crystals from solution SO JOURNAL OF CRYSTAL GROWTH LA English DT Article AB Flow field phenomena in the rapid growth of crystals from solution are studied experimentally. The phenomena studied include large-scale global transport over length scales of the order of the tank dimensions and local stirring of solution near the crystal surface. Convective transport processes in these regimes are explored by flow visualization and fluid velocity measurement techniques. Based upon these data, scaling laws are developed that relate fluid dynamics to geometric and operating parameters employed in rapid growth from solution. Observations indicate that upon start of rotation of the crystal, a vortex forms off each corner of the crystal, which dominates the initial flow field both local to the crystal and globally. The strength of this vortex is shown to scale with the rotation rate times a characteristic length squared (omega L-2). After the initial flow held develops, a characteristic time is observed at which the magnitude of the velocity fluctuations decrease at a rate inversely proportional to the square root of the number of revolutions the crystal has undergone. At large times a steady-state condition is attained and the turbulence intensity decreases to a minimum value proportional to omega L. Relevance of these results to scale-up of mixing involving rotating bluff bodies is provided. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP Maynes, D (reprint author), UNIV UTAH,DEPT MECH ENGN,2415 MEB,SALT LAKE CITY,UT 84112, USA. OI Klewicki, Joseph/0000-0002-4921-3272 NR 14 TC 7 Z9 7 U1 1 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 JUL PY 1997 VL 178 IS 4 BP 545 EP 558 DI 10.1016/S0022-0248(96)01192-X PG 14 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA XN144 UT WOS:A1997XN14400015 ER PT J AU Liu, KC Stevens, CO Brinkman, CR Holshauser, NE AF Liu, KC Stevens, CO Brinkman, CR Holshauser, NE TI A technique to achieve uniform stress distribution in compressive creep testing of advanced ceramics at high temperatures SO JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME LA English DT Article; Proceedings Paper CT 41st International Gas Turbine and Aeroengine Congress and Exhibition CY JUN 10-13, 1996 CL BIRMINGHAM, ENGLAND ID STRENGTH AB A technique to achieve stable and uniform uniaxial compression is offered for creep testing of advanced ceramic materials at elevated temperatures, using an innovative self-aligning load-train assembly. Excellent load-train alignment is attributed to the inherent ability of a unique hydraulic universal coupler to maintain self-aligning. Details of key elements, design concept, and principles of operation of the self-aligning coupler are described. A method of alignment verification using a strain-gaged specimen is then discussed. Results of verification tests indicate that bending below 1.5 percent is routinely achievable with the use of the load-train system. A successful compression creep test is demonstrated using a dumb-bell-shaped silicon nitride specimen tested at 1300 degrees C for a period in excess of 4000 h. C1 N CAROLINA AGR & TECH STATE UNIV,DEPT MECH ENGN,GREENSBORO,NC 27411. RP Liu, KC (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,POB 2008,OAK RIDGE,TN 37831, USA. NR 11 TC 5 Z9 5 U1 0 U2 1 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0742-4795 J9 J ENG GAS TURB POWER JI J. Eng. Gas. Turbines Power-Trans. ASME PD JUL PY 1997 VL 119 IS 3 BP 500 EP 505 DI 10.1115/1.2817012 PG 6 WC Engineering, Mechanical SC Engineering GA XQ142 UT WOS:A1997XQ14200002 ER PT J AU Morris, SC AF Morris, SC TI Risk-based environmental remediation: Introduction SO JOURNAL OF ENVIRONMENTAL ENGINEERING-ASCE LA English DT Article RP Morris, SC (reprint author), BROOKHAVEN NATL LAB,BIOMED & ENVIRONM ASSESSMENT GRP,UPTON,NY 11973, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ASCE-AMER SOC CIVIL ENGINEERS PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 SN 0733-9372 J9 J ENVIRON ENG-ASCE JI J. Environ. Eng.-ASCE PD JUL PY 1997 VL 123 IS 7 BP 626 EP 627 DI 10.1061/(ASCE)0733-9372(1997)123:7(626) PG 2 WC Engineering, Environmental; Engineering, Civil; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA XF801 UT WOS:A1997XF80100003 ER PT J AU Tucker, MD Barton, LL Thomson, BM AF Tucker, MD Barton, LL Thomson, BM TI Reduction and immobilization of molybdenum by Desulfovibrio desulfuricans SO JOURNAL OF ENVIRONMENTAL QUALITY LA English DT Article ID URANIUM AB The mobility of Mo in the environment is strongly dependent on its chemical oxidation state. Under oxidizing conditions, Mo occurs as highly soluble and mobile Mo(VI) and Mo(V) compounds. However, under reducing conditions Mo usually forms insoluble Mo(IV) phases. The objective of this study was to demonstrate the ability of the sulfate-reducing bacterium, Desulfovibrio desulfuricans, to reduce Mo(VI) to Mo(IV) in anaerobic environments. Molybdenum-VI was reduced to Mo(IV) by washed cells of D. desulfuricans suspended in bicarbonate buffer solution with either lactate or H-2 as the electron donor and Mo(VI) as the electron acceptor. Molybdenum-VI reduction by D. desulfuricans in the presence of sulfide resulted in the extracellular precipitation of the mineral molybdenite [MoS2(s)]. Molybdenum-VI reduction did not occur in the absence of an electron donor or in the presence of heat-killed cells of D. desulfuricans. Attempts to grow D. desulfuricans with Mo(VI) as the sole electron acceptor were unsuccessful. Direct chemical reduction of Mo(VI) by sulfide or by H-2 was also unsuccessful, even when heat-killed cells of D. desulfuricans were added to provide a potential catalytic surface for the nonenzymatic reaction. Desulfovibrio vulgaris reduced Mo(VI) Mo(IV) equally well. The results indicate that enzymatic reduction of Mo(VI) by sulfate-reducing bacteria may contribute to the accumulation of Mo(IV) in anaerobic environments and that these organisms may be useful for removing soluble Mo from contaminated water. C1 UNIV NEW MEXICO,DEPT BIOL,ALBUQUERQUE,NM 87131. UNIV NEW MEXICO,DEPT CIVIL ENGN,ALBUQUERQUE,NM 87131. RP Tucker, MD (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. NR 20 TC 30 Z9 34 U1 1 U2 10 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 JUL-AUG PY 1997 VL 26 IS 4 BP 1146 EP 1152 PG 7 WC Environmental Sciences SC Environmental Sciences & Ecology GA XN531 UT WOS:A1997XN53100032 ER PT J AU Matveenko, SI Bishop, AR Balatsky, AV AF Matveenko, SI Bishop, AR Balatsky, AV TI Superconductivity fluctuations in a one-dimensional two-band electron-phonon model with strong repulsive interactions SO JOURNAL OF EXPERIMENTAL AND THEORETICAL PHYSICS LA English DT Article ID CHAINS; GAS AB We study a one-dimensional, two-band model with short-range electron-electron repulsions (onsite U and nearest-neighbor V terms) and electron-phonon coupling. We show that there is a region of U, V and band filling in which singlet superconductivity fluctuations are dominant. This region is absent without electron-phonon interactions and includes large values of U and V. (C) 1997 American Institute of Physics. C1 LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. RP Matveenko, SI (reprint author), LD LANDAU THEORET PHYS INST,KOSYGINA 2,MOSCOW 117940,RUSSIA. NR 10 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1063-7761 J9 J EXP THEOR PHYS+ JI J. Exp. Theor. Phys. PD JUL PY 1997 VL 85 IS 1 BP 163 EP 167 DI 10.1134/1.558300 PG 5 WC Physics, Multidisciplinary SC Physics GA XT450 UT WOS:A1997XT45000025 ER PT J AU Li, XL Baker, DN Temerin, M Cayton, TE Reeves, EGD Christensen, RA Blake, JB Looper, MD Nakamura, R Kanekal, SG AF Li, XL Baker, DN Temerin, M Cayton, TE Reeves, EGD Christensen, RA Blake, JB Looper, MD Nakamura, R Kanekal, SG TI Multisatellite observations of the outer zone electron variation during the November 3-4, 1993, magnetic storm SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article; Proceedings Paper CT Chapman Conference on Magnetic Storms CY FEB 12-16, 1996 CL CALIF INST TECHNOL, PROPULS LAB, PASADENA, CA HO CALIF INST TECHNOL, PROPULS LAB ID RADIATION-BELT; RELATIVISTIC ELECTRONS; ENERGETIC PARTICLES; MIDDLE ATMOSPHERE; MARCH 24; ENERGIZATION; SIMULATION; MAGNETOSPHERE; RECIRCULATION; PRECIPITATION AB The disappearance and reappearance of outer zone energetic electrons during the November 3-4, 1993, magnetic storm is examined utilizing data from the Solar, Anomalous, and Magnetospheric Particle Explorer (SAMPEX), the Global Positioning System (GPS) series, and the Los Alamos National Laboratory (LANL) sensors onboard geosynchronous satellites. The relativistic electron flux drops during the main phase of the magnetic storm in association with the large negative interplanetary B-z and rapid solar wind pressure increase late on November 3. Outer zone electrons with E > 3 MeV measured by SAMPEX disappear for over 12 hours at the beginning of November 4. This represents a 3 orders of magnitude decrease down to the cosmic ray background of the detector. GPS and LANL sensors show similar effects, confirming that the flux drop of the energetic electrons occurs near the magnetic equator and at all pitch angles. Enhanced electron precipitation was measured by SAMPEX at L greater than or equal to 3.5. The outer zone electron fluxes then recover and exceed prestorm levels within one day of the storm onset and the inner boundary of the outer zone moves inward to smaller L (<3). These multiple-satellite measurements provide a data set which is examined in detail and used to determine the mechanisms contributing to the loss and recovery of the outer zone electron flux. The loss of the inner part of the outer zone electrons is partly due to the adiabatic effects associated with the decrease of Dst, while the loss of most of the outer part (those electrons initially at L greater than or equal to 4.0) are due to either precipitation into the atmosphere or drift to the magnetopause because of the strong compression of the magnetosphere by the solar wind. The recovery of the energetic electron flux is due to the adiabatic effects associated with the increase in Dst, and at lower energies (<0.5 MeV) due to rapid radial diffusion driven by the strong magnetic activity during the recovery phase of the storm. Heating of the electrons by waves may contribute to the energization of the more energetic part (>1.0 MeV) of the outer zone electrons. C1 AEROSP CORP,DEPT SPACE SCI,LOS ANGELES,CA 90009. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. NAGOYA UNIV,STEL,TOYOKAWA,AICHI 442,JAPAN. UNIV CALIF BERKELEY,SPACE SCI LAB,BERKELEY,CA 94720. RP Li, XL (reprint author), UNIV COLORADO,ATMOSPHER & SPACE PHYS LAB,1234 INNOVAT DR,BOULDER,CO 80303, USA. RI Nakamura, Rumi/I-7712-2013; Reeves, Geoffrey/E-8101-2011 OI Nakamura, Rumi/0000-0002-2620-9211; Reeves, Geoffrey/0000-0002-7985-8098 NR 46 TC 210 Z9 214 U1 0 U2 12 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD JUL 1 PY 1997 VL 102 IS A7 BP 14123 EP 14140 DI 10.1029/97JA01101 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA XJ204 UT WOS:A1997XJ20400010 ER PT J AU Baker, DN Li, X Turner, N Allen, JH Bargatze, LF Blake, JB Sheldon, RB Spence, HE Belian, RD Reeves, GD Kanekal, SG Klecker, B Lepping, RP Ogilvie, K Mewaldt, RA Onsager, T Singer, HJ Rostoker, G AF Baker, DN Li, X Turner, N Allen, JH Bargatze, LF Blake, JB Sheldon, RB Spence, HE Belian, RD Reeves, GD Kanekal, SG Klecker, B Lepping, RP Ogilvie, K Mewaldt, RA Onsager, T Singer, HJ Rostoker, G TI Recurrent geomagnetic storms and relativistic electron enhancements in the outer magnetosphere: ISTP coordinated measurements SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article; Proceedings Paper CT Chapman Conference on Magnetic Storms CY FEB 12-16, 1996 CL CALIF INST TECHNOL, PROPULS LAB, PASADENA, CA HO CALIF INST TECHNOL, PROPULS LAB ID SOLAR; SPACECRAFT; TELESCOPE; PARTICLE; SAMPEX AB New, coordinated measurements from the International Solar-Terrestrial Physics (ISTP) constellation of spacecraft are presented to show the causes and effects of recurrent geomagnetic activity during recent solar minimum conditions. It is found using WIND and POLAR data that even for modest geomagnetic storms, relativistic electron fluxes are strongly and rapidly enhanced within the outer radiation zone of the Earth's magnetosphere. Solar wind data are utilized to identify the drivers of magnetospheric acceleration processes. Yohkoh solar soft X-ray data are also used to identify the solar coronal holes that produce the high-speed solar wind streams which, in turn, cause the recurrent geomagnetic activity. It is concluded that even during extremely quiet solar conditions (sunspot minimum) there are discernible coronal holes and resultant solar wind streams which can produce intense magnetospheric particle acceleration. As a practical consequence of this Sun-Earth connection, it is noted that a long-lasting E>1MeV electron event in late March 1996 appears to have contributed significantly to a major spacecraft (Anik E1) operational failure. C1 NOAA,NATL GEOPHYS DATA CTR,SCOSTEP SECRETARIAT,BOULDER,CO 80302. MONTANA STATE UNIV,DEPT PHYS,BOZEMAN,MT 59717. AEROSP CORP,LOS ANGELES,CA 90009. BOSTON UNIV,CTR SPACE PHYS,BOSTON,MA 02215. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. NASA,GODDARD SPACE FLIGHT CTR,HUGHES STX,GREENBELT,MD 20771. MAX PLANCK INST PHYS & ASTROPHYS,D-8046 GARCHING,GERMANY. CALTECH,PASADENA,CA 91125. NOAA,RESE,SPACE ENVIRONM CTR,BOULDER,CO 80302. UNIV ALBERTA,DEPT PHYS,EDMONTON,AB,CANADA. RP Baker, DN (reprint author), UNIV COLORADO,ATMOSPHER & SPACE PHYS LAB,CAMPUS BOX 590,BOULDER,CO 80303, USA. RI Spence, Harlan/A-1942-2011; Reeves, Geoffrey/E-8101-2011; OI Reeves, Geoffrey/0000-0002-7985-8098; Turner, Niescja/0000-0002-3280-4260 NR 24 TC 103 Z9 104 U1 0 U2 6 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD JUL 1 PY 1997 VL 102 IS A7 BP 14141 EP 14148 DI 10.1029/97JA00565 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA XJ204 UT WOS:A1997XJ20400011 ER PT J AU Hoogeveen, GW Jacobson, AR AF Hoogeveen, GW Jacobson, AR TI Radio interferometer measurements of plasmasphere density structures during geomagnetic storms SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article; Proceedings Paper CT Chapman Conference on Magnetic Storms CY FEB 12-16, 1996 CL CALIF INST TECHNOL, PROPULS LAB, PASADENA, CA HO CALIF INST TECHNOL, PROPULS LAB ID MID-LATITUDES; IONOSPHERIC DISTURBANCES; ELECTRIC-FIELDS; MAGNETIC STORM; SAINT-SANTIN; CONVECTION; PLASMAPAUSE; SIGNATURES; BEHAVIOR; ARRAY AB The Los Alamos plasmaspheric drift radio interferometer is a ground-based array that regularly measures periodic disturbances in the plasmasphere. These plasmaspheric density structures have been shown to depend on geomagnetic activity, as indicated by Kp. However, a direct storm time analysis of their behavior has not been done. This paper studies the amplitude, drift velocity, and location of these structures before, during, and after the onset of major geomagnetic storms. Distinct large-amplitude, storm time signatures are found during the first night after onset, continuing through the third night; there were significantly more storm time signatures during nighttime than daytime. The L shells on which the disturbances existed were found to decrease after storm onset, indicating a possible shrinking of the plasmasphere. RP Hoogeveen, GW (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 26 TC 10 Z9 10 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD JUL 1 PY 1997 VL 102 IS A7 BP 14177 EP 14188 DI 10.1029/97JA00484 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA XJ204 UT WOS:A1997XJ20400015 ER PT J AU Shiokawa, K Meng, CI Reeves, GD Rich, FJ Yumoto, K AF Shiokawa, K Meng, CI Reeves, GD Rich, FJ Yumoto, K TI A multievent study of broadband electrons observed by the DMSP satellites and their relation to red aurora observed at midlatitude stations SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article; Proceedings Paper CT Chapman Conference on Magnetic Storms CY FEB 12-16, 1996 CL CALIF INST TECHNOL, PROPULS LAB, PASADENA, CA HO CALIF INST TECHNOL, PROPULS LAB ID GREAT MAGNETIC STORM; LOW-LATITUDE AURORAE; PARTICLE-PRECIPITATION; FIELDS; MAGNETOSPHERE; ATMOSPHERE; SUBSTORM; EMISSION; ZONE AB Broadband electrons during magnetic storms are characterized by an unusually intense flux of precipitating electrons in the broadband energy range from 30 eV to 30 keV near the equatorward edge of the auroral oval (47 degrees-66 degrees magnetic latitude). Broadband electrons were first reported by Shiokawa et al. [1996]. In this paper, we report a multievent study of broadband electrons, using particle data obtained by the Defense Meteorological Satellite Program (DMSP) satellites during 23 magnetic storms from January 1989 through May 1992. Twelve broadband electron events are identified. Most of them are observed in the night sector, but some are observed in the morning sector. Particle data for successive polar passes of the DMSP multisatellites are used to show that broadband electrons generally last for less than 30 min and that for some events, they precipitate over a wide range of local times simultaneously. On the basis of a quantitative calculation of optical emissions from electrons in the neutral atmosphere, we conclude that broadband electrons are a possible cause of red auroras observed at midlatitude ground stations. We suggest that broadband electrons are associated with certain substorms during the main phase of magnetic storms. This conjecture comes from observations of H component positive bays and Pi 2 pulsations observed at low-latitude magnetic stations and from magnetic field variations observed at geosynchronous satellites. We conclude that the magnetospheric source of broadband electrons lies within the inner part of the plasma sheet. This conclusion is based on the facts that broadband electrons appear in latitudes where plasma sheet particles were observed before the event and that broadband electrons are observed poleward of the subauroral ion drifts, a position that corresponds to the inner edge of the injected particle layer during storms. High-energy particle data obtained at geosynchronous satellites show that both strong magnetopause compressions in the dayside and decrease of the particle fluxes in the nightside occur in association with the broadband electron events. Possible mechanisms of broadband electron production are discussed. C1 JOHNS HOPKINS UNIV,APPL PHYS LAB,BALTIMORE,MD 20723. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. AIR FORCE GEOPHYS LAB,HANSCOM AFB,MA 01731. KYUSHU UNIV,FAC SCI,FUKUOKA 812,JAPAN. RP Shiokawa, K (reprint author), NAGOYA UNIV,SOLAR TERR ENVIRONM LAB,TOYOKAWA 442,JAPAN. RI Reeves, Geoffrey/E-8101-2011 OI Reeves, Geoffrey/0000-0002-7985-8098 NR 29 TC 25 Z9 24 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD JUL 1 PY 1997 VL 102 IS A7 BP 14237 EP 14253 DI 10.1029/97JA00741 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA XJ204 UT WOS:A1997XJ20400021 ER PT J AU Zhou, XY Russell, CT Gosling, JT Mitchell, DG AF Zhou, XY Russell, CT Gosling, JT Mitchell, DG TI Three spacecraft observations of the geomagnetic tail during moderately disturbed conditions: Structure and evolution of the current sheet SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID THIN CURRENT SHEETS; PLASMA SHEET; MAGNETIC-FIELD; EARTHS MAGNETOTAIL; POLYTROPIC INDEX; GROWTH-PHASE; SUBSTORMS; CONVECTION; MODEL AB On April 22, 1979, from 0840 to 1018 UT, ISEE 1 and ISEE 2 stayed in the tail current sheet at 17 R-E, crossing the current sheet center several times while the initially northward interplanetary magnetic field Bz turned southward under conditions of constant solar wind velocity and dynamic pressure. An overview of the period from 0840 to 1050 UT, discussing the solar wind conditions, the tail magnetic field response at ISEE 1, ISEE 2 and IMP 8, and the ground electrojet activities has been presented in an accompanying paper. Herein under the assumption that the magnetic field is antisymmetric about the current sheet center, the hyperbolic tangent current sheet model of Harris has been used to calculate the current sheet thickness from these two close spacecraft measurements of the tail magnetic field. The thickness varied from 2.5 to 0.5 R-E during this period. The current sheet thinned just prior to a rapid poleward expansion of the auroral electrojet and just after the arrival of a southward turning of the IMF Bz and apparent tail field reconnection at ISEE 1 and 2. The plasma density and temperature distribution in the vertical direction appears to be close to adiabatic at this time and the total pressure is roughly constant through the lobe. In this case study, the polytropic index of the tail plasma is found to be 5/3 on the average. This implies that the plasma convection at 17 R-E in tail was steadily adiabatic over the period of about 100 min. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. JOHNS HOPKINS UNIV,APPL PHYS LAB,LAUREL,MD 20723. UNIV CALIF LOS ANGELES,INST GEOPHYS & PLANETARY PHYS,LOS ANGELES,CA 90095. RP Zhou, XY (reprint author), CHINESE ACAD SCI,INST GEOPHYS,BEIJING 100101,PEOPLES R CHINA. NR 28 TC 15 Z9 15 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD JUL 1 PY 1997 VL 102 IS A7 BP 14415 EP 14424 DI 10.1029/97JA00038 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA XJ204 UT WOS:A1997XJ20400035 ER PT J AU Riley, P Gosling, JT Pizzo, VJ AF Riley, P Gosling, JT Pizzo, VJ TI A two-dimensional simulation of the radial and latitudinal evolution of a solar wind disturbance driven by a fast, high-pressure coronal mass ejection SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID REVERSE SHOCK PAIRS; INTERPLANETARY; ULYSSES; MHD AB Using a hydrodynamic simulation, we have studied the two-dimensional (symmetry in the azimuthal direction) evolution of a fast, high-pressure coronal mass ejection (CME) ejected into a solar wind with latitudinal variations similar to those observed by Ulysses. Specifically, the latitudinal structure of the ambient solar wind in the meridional plane is approximated by two zones: At low latitudes (< 20 degrees) the solar wind is slow and dense, while at higher latitudes the solar wind is fast and tenuous. The CME is introduced into this ambient wind as a bell-shaped pressure pulse in time, spanning from the equator to 45 degrees with a speed and temperature equal to that of the high-latitude solar wind. We find that such an ejection profile produces radically different disturbance profiles at low and high latitudes. In particular, the low-latitude portion of the ejecta material drives a highly asymmetric disturbance because of the relative difference in speed between the fast CME and slower ambient solar wind ahead. In contrast, the high-latitude portion of the same ejecta material drives a much more radially symmetric disturbance because the relative difference in pressure between the CME and ambient background plasma dominates the dynamics. The simulations reveal a number of other interesting features. First, there is significant distortion of the CME in the interplanetary medium. By similar to 1 AU the CME has effectively separated (in radius as well as latitude) into two pieces. The radial separation is due to the strong velocity shear between the slow and fast ambient solar wind. The latitudinal separation arises from pressure gradients associated with rarefaction regions that develop as the CME propagates outward. Second, there is significant poleward motion of the highest-latitude portion of the CME and its associated disturbance. The main body of the CME expands poleward by similar to 18 degrees, while the forward and reverse waves (produced by the overexpanding portion of the CME) propagate all the way to the pole. Third, the simulations shaw that the high-pressure region, which develops at low latitudes as the fast CME ploughs through the slow ambient solar wind, penetrates significantly (similar to 10 degrees) into the high-latitude fast solar wind. We compare the simulation results with a CME-driven interplanetary disturbance observed at both low and high latitudes and find that the simulation reproduces many of the essential features of the observations. C1 NOAA,SPACE ENVIRONM LAB,BOULDER,CO 80303. RP Riley, P (reprint author), LOS ALAMOS NATL LAB,SPACE & ATMOSPHER SCI GRP,POB 1663,NIS-1,MS D466,LOS ALAMOS,NM 87545, USA. NR 20 TC 66 Z9 66 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD JUL 1 PY 1997 VL 102 IS A7 BP 14677 EP 14685 DI 10.1029/97JA01131 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA XJ204 UT WOS:A1997XJ20400055 ER PT J AU Szoke, A AF Szoke, A TI Holographic microscopy with a complicated reference SO JOURNAL OF IMAGING SCIENCE AND TECHNOLOGY LA English DT Article ID X-RAY CRYSTALLOGRAPHY; ELECTRON-MICROSCOPY; ATOMIC-RESOLUTION; DIFFRACTION; LIMITATIONS; IMAGES; LIMIT AB In recent years three-dimensional images at atomic resolution have been obtained by holography as well as by x-ray crystallography. In this report we explore the connections between these two methods from a unified point of view. To recover the unknown structure we use mathematical methods developed for the solution of Inverse problems. We review relevant experiments and discuss some ideas that may lead to more powerful imaging methods in the future. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Szoke, A (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 50 TC 15 Z9 15 U1 0 U2 1 PU I S & T - SOC IMAGING SCIENCE TECHNOLOGY PI SPRINGFIELD PA 7003 KILWORTH LANE, SPRINGFIELD, VA 22151 USA SN 8750-9237 J9 J IMAGING SCI TECHN JI J. Imaging Sci. Technol. PD JUL-AUG PY 1997 VL 41 IS 4 BP 332 EP 341 PG 10 WC Imaging Science & Photographic Technology SC Imaging Science & Photographic Technology GA ZC811 UT WOS:000072620500005 ER PT J AU Chen, P AF Chen, P TI On intelligent robot motion planning via learning SO JOURNAL OF INTELLIGENT & ROBOTIC SYSTEMS LA English DT Article DE robotics; motion planning; learning ID FREEDOM; SPACE AB Automatic motion planning is one of the basic modules that are needed to increase robot intelligence and usability. Unfortunately, the inherent complexity of motion planning has rendered traditional search algorithms incapable of solving every problem in real time. To circumvent this difficulty, we explore the alternative of allowing human operators to participate in the problem solving process. By having the human operator teach during difficult motion planning episodes, the robot should be able to learn and improve its own motion planning capability and gradually reduce its reliance on the human operator. In this paper, we present such a learning framework in which both human and robot can cooperate to achieve real-time automatic motion planning. To enable a deeper understanding of the framework in terms of performance, we present it as a simple learning algorithm and provide theoretical analysis of its behavior. In particular, we characterize the situations in which learning is useful, and provide quantitative bounds to predict the necessary training time and the maximum achievable speedup in planning time. RP SANDIA NATL LABS, POB 5800, ALBUQUERQUE, NM 87185 USA. NR 26 TC 3 Z9 3 U1 1 U2 2 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0921-0296 EI 1573-0409 J9 J INTELL ROBOT SYST JI J. Intell. Robot. Syst. PD JUL PY 1997 VL 19 IS 3 BP 299 EP 320 DI 10.1023/A:1007981604566 PG 22 WC Computer Science, Artificial Intelligence; Robotics SC Computer Science; Robotics GA XV372 UT WOS:A1997XV37200004 ER PT J AU Vanheusden, K Seager, CH Warren, WL Tallant, DR Caruso, J HampdenSmith, MJ Kodas, TT AF Vanheusden, K Seager, CH Warren, WL Tallant, DR Caruso, J HampdenSmith, MJ Kodas, TT TI Green photoluminescence efficiency and free-carrier density in ZnO phosphor powders prepared by spray pyrolysis SO JOURNAL OF LUMINESCENCE LA English DT Article DE electron spin resonance; donors; intrinsic luminescence; Emitting centers; ZnO ID CERAMICS; DEFECTS AB Electron paramagnetic resonance, optical absorption, and photoluminescence spectroscopy have been combined to characterize ZnO powders that were prepared by spray pyrolysis. We generally observe a good correlation between the 510 nm green emission intensity and the density of paramagnetic isolated oxygen vacancies. In addition, both quantities increase with free-carrier concentration n(c), as long as n(c), < 1.4 x 10(18) cm(-3). At higher free-carrier concentrations, both quantities decrease. A model is proposed involving the isolated oxygen vacancy as the luminescence center. C1 NANOCHEM RES INC,ALBUQUERQUE,NM 87122. RP Vanheusden, K (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 18 TC 199 Z9 212 U1 2 U2 26 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-2313 J9 J LUMIN JI J. Lumines. PD JUL PY 1997 VL 75 IS 1 BP 11 EP 16 DI 10.1016/S0022-2313(96)00096-8 PG 6 WC Optics SC Optics GA XM331 UT WOS:A1997XM33100002 ER PT J AU Thiyagarajan, P Zeng, FW Ku, CY Zimmerman, SC AF Thiyagarajan, P Zeng, FW Ku, CY Zimmerman, SC TI SANS investigation of self-assembling dendrimers in organic solvents SO JOURNAL OF MATERIALS CHEMISTRY LA English DT Article ID ANGLE NEUTRON-SCATTERING; BIOLOGICAL STRUCTURES; PERSPECTIVES; ORGANIZATION; CHEMISTRY; SIZE AB The self-assembly behaviour of tetraacids 1a-c and tetraester 4 in CDCl3 and [H-2(8)]tetrahydrofuran {[H-2(8)]THF} has been investigated by the small-angle neutron scattering (SANS)technique. The experimental SANS data were compared with simulated scattering data derived from structural models proposed previously for the aggregates. These studies suggest that dendritic monomers 1b,c self-assemble into cyclic hexameric aggregates, whereas la forms a large tubular aggregate in CDCl3. Further study on 1c in CDCl3 as a function of concentration suggests that the cyclic hexameric aggregates strongly interact with each other at higher concentrations. The control compound 4 was shown to be monomeric in both solvents. C1 UNIV ILLINOIS,DEPT CHEM,URBANA,IL 61801. RP Thiyagarajan, P (reprint author), ARGONNE NATL LAB,IPNS,ARGONNE,IL 60439, USA. RI Zimmerman, Steven/E-4244-2010 OI Zimmerman, Steven/0000-0002-5333-3437 NR 29 TC 29 Z9 30 U1 0 U2 2 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON ROAD, CAMBRIDGE, CAMBS, ENGLAND CB4 4WF SN 0959-9428 J9 J MATER CHEM JI J. Mater. Chem. PD JUL PY 1997 VL 7 IS 7 BP 1221 EP 1226 DI 10.1039/a700581d PG 6 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA XK011 UT WOS:A1997XK01100018 ER PT J AU Cao, SQ Pedraza, AJ Allard, LF Lowndes, DH AF Cao, SQ Pedraza, AJ Allard, LF Lowndes, DH TI The effects of the atmosphere on the surface modification of alumina by pulsed-laser-irradiation SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID ADHESION; SAPPHIRE; FILMS AB A near-surface thin layer is melted when alumina is pulsed-laser-irradiated in an Ar-4% H-2 atmosphere or in air. A thin layer of amorphous phase forms when the substrates are irradiated in Ar-4% H-2 at 1 to 1.3 J/cm(2) with multiple laser pulses. Amorphous phase is also found in samples laser-irradiated in air and oxygen. After a laser pulse at an energy density of 1.6 J/cm(2) or higher the melt solidifies epitaxially from the unmelted substrate with a cellular microstructure. There is a decrease in the cooling rate of the melt as the laser energy density is increased because more heat must be dissipated. The amorphous phase forms when the heat input due to the laser pulse produces a superheated melt that cools down sufficiently fast to avoid crystallization. Very small particles of aluminum in the laser-melted and subsequently solidified layer are observed only in samples laser-irradiated in an Ar-4% H-2 atmosphere. In this reducing atmosphere, the alumina is possibly reduced to metallic aluminum which is mixed into the melt by the turbulence provoked by the laser pulses. The effects of these metallic particles on copper deposition when the irradiated substrates are immersed in an electroless bath are discussed. C1 OAK RIDGE NATL LAB,HIGH TEMP MAT LAB,OAK RIDGE,TN 37831. OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. RP Cao, SQ (reprint author), UNIV TENNESSEE,DEPT MAT SCI & ENGN,KNOXVILLE,TN 37996, USA. NR 22 TC 11 Z9 11 U1 0 U2 4 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD JUL PY 1997 VL 12 IS 7 BP 1747 EP 1754 DI 10.1557/JMR.1997.0241 PG 8 WC Materials Science, Multidisciplinary SC Materials Science GA XJ194 UT WOS:A1997XJ19400014 ER PT J AU Yu, N Devanathan, R Sickafus, KE Nastasi, M AF Yu, N Devanathan, R Sickafus, KE Nastasi, M TI Radiation-induced phase transformations in MgAl2O4 spinel SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID SOLID-STATE AMORPHIZATION; IRRADIATION DAMAGE; ALUMINATE SPINEL; ION; MICROSTRUCTURE; HARDNESS; SYSTEM; MGO AB Ion-irradiation was observed to transform MgAl2O4 spinel first to a metastable crystalline phase and then to an amorphous phase at cryogenic temperatures. Elastic stiffening of 15% occurred upon formation of the metastable crystalline phase. A second transformation from the metastable crystalline spinel to an amorphous state was accompanied by elastic softening of 25% relative to unirradiated spinel. This phase transformation behavior in spinel appears to be different from that in intermetallic compounds where only elastic softening associated with radiation damage accumulation is observed. A two-stage radiation damage model is proposed to explain the observed phase transformations. C1 TEXAS INSTRUMENTS INC,SEMICOND PROC & DEVICE CTR,DALLAS,TX 75243. RP Yu, N (reprint author), LOS ALAMOS NATL LAB,DIV MAT SCI & TECHNOL,LOS ALAMOS,NM 87545, USA. RI Devanathan, Ram/C-7247-2008 OI Devanathan, Ram/0000-0001-8125-4237 NR 25 TC 20 Z9 20 U1 1 U2 8 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD JUL PY 1997 VL 12 IS 7 BP 1766 EP 1770 DI 10.1557/JMR.1997.0243 PG 5 WC Materials Science, Multidisciplinary SC Materials Science GA XJ194 UT WOS:A1997XJ19400016 ER PT J AU Meldrum, A Boatner, LA Ewing, RC AF Meldrum, A Boatner, LA Ewing, RC TI Electron-irradiation-induced nucleation and growth in amorphous LaPO4, ScPO4, and zircon SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID BEAM-INDUCED AMORPHIZATION; SELF-RADIATION DAMAGE; SOLID-PHASE EPITAXY; ION-BEAM; INDUCED CRYSTALLIZATION; CRYSTAL NUCLEATION; CERAMIC INSULATORS; ROOM-TEMPERATURE; SILICON; SI AB Synthetic LaPO4, ScPO4, and crystalline natural zircon (ZrSiO4) from Mud Tanks, Australia were irradiated by 1.5 MeV Kr+ ions until complete amorphization occurred as indicated by the absence of electron-diffraction maxima. The resulting amorphous materials were subsequently irradiated by an 80 to 300 keV electron beam in the transmission electron microscope at temperatures between 130 and 800 K, and the resulting microstructural changes were monitored in situ. Thermal anneals in the range of 500 to 600 K were also conducted to compare the thermally induced microstructural development with that produced by the electron irradiations. Amorphous LaPO4 and ScPO4 annealed to form a randomly oriented polycrystalline assemblage of the same composition as the original material, but zircon recrystallized to ZrO2 (zirconia) + amorphous SiO2 for all beam energies and temperatures investigated. The rate of crystallization increased in the order: zircon, ScPO4, LaPO4. Submicrometer tracks of crystallites having a width equal to that of the electron beam could be ''drawn'' on the amorphous substrate. In contrast, thermal annealing resulted in epitaxial recrystallization from the thick edges of the TEM samples, Electron-irradiation-induced nucleation and growth in these materials can be explained by a combination of radiation-enhanced diffusion as a result of ionization processes and a strong thermodynamic driving force for crystallization. The structure of the amorphous orthophosphates may be less rigid than that of their silicate analogues because of the lower coordination across the PO4 tetrahedron, and thus a lower energy is required for reorientation and recrystallization. The more highly constrained monazite structure-type recovers at a lower electron dose than the zircon structure-type, consistent with recent models used to predict the crystalline-to-amorphous transition as a result of ion irradiation. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP Meldrum, A (reprint author), UNIV NEW MEXICO,DEPT EARTH & PLANETARY SCI,ALBUQUERQUE,NM 87131, USA. RI Boatner, Lynn/I-6428-2013 OI Boatner, Lynn/0000-0002-0235-7594 NR 60 TC 67 Z9 67 U1 4 U2 21 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD JUL PY 1997 VL 12 IS 7 BP 1816 EP 1827 DI 10.1557/JMR.1997.0250 PG 12 WC Materials Science, Multidisciplinary SC Materials Science GA XJ194 UT WOS:A1997XJ19400023 ER PT J AU Noever, D Sibille, L Cronise, R Baskaran, S Hunt, A AF Noever, D Sibille, L Cronise, R Baskaran, S Hunt, A TI Neural net formulations for organically modified, hydrophobic silica aerogel SO JOURNAL OF MATERIALS RESEARCH LA English DT Article AB Organic modification of aerogel chemical formulations is known to transfer desirable hydrophobicity to lightweight solids. However, the effects of chemical modification on other material constants such as elasticity, compliance, and sound dampening present a difficult optimization problem. Here a statistical treatment of a 9-variable optimization is accomplished with multiple regression and an artificial neural network (ANN). The ANN shows 95% prediction success for the entire data set of elasticity, compared to a multidimensional linear regression which shows a maximum correlation coefficient, R = 0.782. In this case, using the Number of Categories Criterion for the standard multiple regression, traditional statistical methods can distinguish fewer than 1.83 categories (high and low elasticity) and cannot group or cluster the data to give more refined partitions. A nonlinear surface requires at least three categories (high, low, and medium elasticities) to define its curvature. To predict best and worst gellation conditions, organic modification is most consistent with changed elasticity for sterically large groups and high hydroxyl concentrations per unit surface area. The isocontours for best silica and hydroxyl concentration have a complex saddle, the geometrical structure of which would elude a simple experimental design based on usual gradient descent methods for finding optimum. C1 UNIV SPACE RES ASSOC,HUNTSVILLE,AL 35806. INST MOL BIOTECHNOL EV,D-7745 JENA,GERMANY. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP Noever, D (reprint author), NASA,BIOPHYS BRANCH,GEORGE C MARSHALL SPACE FLIGHT CTR,MAIL CODE ES-76,HUNTSVILLE,AL 35812, USA. NR 9 TC 0 Z9 0 U1 1 U2 3 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD JUL PY 1997 VL 12 IS 7 BP 1837 EP 1843 DI 10.1557/JMR.1997.0252 PG 7 WC Materials Science, Multidisciplinary SC Materials Science GA XJ194 UT WOS:A1997XJ19400025 ER PT J AU Gao, Y Bai, G Liang, Y Dunham, GC Chambers, SA AF Gao, Y Bai, G Liang, Y Dunham, GC Chambers, SA TI Structure and surface morphology of highly conductive RuO2 films grown on MgO by oxygen-plasma-assisted molecular beam epitaxy SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID CHEMICAL-VAPOR-DEPOSITION; THIN-FILMS; RUTHENIUM DIOXIDE AB Metallic RuO2(110) thin films were grown by oxygen-plasma-assisted molecular beam epitaxy (MBE) on MgO(100) and (110) at 425 degrees C. RuO2 films on MgO(100) are epitaxial with two variants, while RuO2 films on MgO(110) are highly oriented with the (110) face parallel to the substrate surface. The two variants in the RuO2(110) epitaxial films resulted in a twofold mosaic microstructure, The RuO2(110) epitaxial films are very smooth and exhibit a low resistivity of similar to 36 mu Omega-cm. In contrast, the RuO2(110) textured films are very rough, and consist of small grains with a poor in-plane alignment. A slight higher resistivity (49 mu Omega-cm) was found for the RuO2(110) textured films grown on MgO(110). C1 ARGONNE NATL LAB,ARGONNE,IL 60439. RP Gao, Y (reprint author), PACIFIC NW NATL LAB,POB 999,MS K2-12,RICHLAND,WA 99352, USA. NR 20 TC 28 Z9 29 U1 1 U2 5 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD JUL PY 1997 VL 12 IS 7 BP 1844 EP 1849 DI 10.1557/JMR.1997.0253 PG 6 WC Materials Science, Multidisciplinary SC Materials Science GA XJ194 UT WOS:A1997XJ19400026 ER PT J AU Conzone, SD Butt, DP Bartlett, AH AF Conzone, SD Butt, DP Bartlett, AH TI Joining MoSi2 to 316L stainless steel SO JOURNAL OF MATERIALS SCIENCE LA English DT Article ID THERMAL RESIDUAL-STRESSES; CERAMIC-METAL INTERFACES; FINITE-ELEMENT ANALYSIS; FRACTURE; OXIDATION; CRACKING; FILMS AB The feasibility of joining MoSi2 to 316L stainless steel using active brazing techniques was investigated using two interlayer systems: cusil/Nb/cusil and cusil/Ni/cusil (where cusil is a commercially available Cu-Ag eutectic). Dense, uniform joints were obtained with the cusil/Nb/cusil interlayer system, because the coefficient of thermal expansion (CTE) of niobium closely matched that of NoSi2 over a wide temperature range. Matching the CTEs of MoSi2 and the interlayer material shielded the low-toughness MoSi2 from residual stresses formed during cooling from the joint-processing temperature (830 degrees C). The cusil/Nb/cusil interlayer, however, failed to produce adequate joints because of the large CTE difference between nickel and MoSi2. RP Conzone, SD (reprint author), LOS ALAMOS NATL LAB,DIV MAT SCI & TECHNOL,LOS ALAMOS,NM 87545, USA. RI Butt, Darryl/B-7480-2008 OI Butt, Darryl/0000-0003-4501-8864 NR 17 TC 22 Z9 26 U1 2 U2 8 PU CHAPMAN HALL LTD PI LONDON PA 2-6 BOUNDARY ROW, LONDON, ENGLAND SE1 8HN SN 0022-2461 J9 J MATER SCI JI J. Mater. Sci. PD JUL 1 PY 1997 VL 32 IS 13 BP 3369 EP 3374 DI 10.1023/A:1018656313605 PG 6 WC Materials Science, Multidisciplinary SC Materials Science GA XJ843 UT WOS:A1997XJ84300004 ER PT J AU Sugama, T Lipford, B AF Sugama, T Lipford, B TI Hydrothermal light-weight calcium phosphate cements: Use of polyacrylnitrile-shelled hollow microspheres SO JOURNAL OF MATERIALS SCIENCE LA English DT Article ID CARBONATION AB Calcium phosphate cement (CPC) slurries with a very low density of less than 1.0 g cm(-3) were prepared by incorporating polyacrylnitrile (PAN)-shelled hollow microspheres with calcite sizing into CPC pastes consisting of sodium metaphosphate, high alumina cement and water. Their characterizations were then investigated to assess their value as light-weight CPC cementing materials for use in geothermal wells at hydrothermal temperatures up to 300 degrees C. This light-weight cement showed the following four main features: firstly the chemical inertness of the PAN shells to CPC served to extend thickening time of the slurry; secondly the microsphere surfaces preferentially absorbed Al ions from among the various ionic species in the interstitial fluid of CPC at 100 degrees C, thereby forming amorphous Al-enriched sodium phosphate hydrates as interfacial intermediate layers which tightly linked the microspheres to the CPC matrix; thirdly although the thermal decomposition of PAN shells around 200 degrees C generated numerous voids in the cement body, these open spaces were filled by well-grown wardite crystals formed by the in-situ phase transformation of amorphous sodium aluminate phosphate hydrates, thereby preventing a serious loss in strength of the light-weight calcium phosphate cement (LCPC) specimens; fourthly the major phase composition of CPC matrix at 200 and 300 degrees C consisted of well-crystallized hydroxyapatite and boehmite compounds which can be categorized as alkali carbonation-resistant phases. The integration of these characteristics was responsible for maintaining the compressive strength of greater than 0.6 MPa for LCPC specimens derived from a very-low-density (0.98 g cm(-3)) slurry exposed for 6 months to a 0.05 M Na2CO3-laden solution at 250 degrees C. C1 ALABAMA A&M UNIV,DEPT PHYS,NORMAL,AL 35762. RP Sugama, T (reprint author), ASSOCIATED UNIV INC,BROOKHAVEN NATL LAB,DEPT APPL SCI,ENERGY EFFICIENCY & CONSERVAT DIV,UPTON,NY 11972, USA. NR 8 TC 14 Z9 15 U1 2 U2 14 PU CHAPMAN HALL LTD PI LONDON PA 2-6 BOUNDARY ROW, LONDON, ENGLAND SE1 8HN SN 0022-2461 J9 J MATER SCI JI J. Mater. Sci. PD JUL 1 PY 1997 VL 32 IS 13 BP 3523 EP 3534 DI 10.1023/A:1018601623600 PG 12 WC Materials Science, Multidisciplinary SC Materials Science GA XJ843 UT WOS:A1997XJ84300026 ER PT J AU Yu, XY Day, DE Long, GJ Brow, RK AF Yu, XY Day, DE Long, GJ Brow, RK TI Properties and structure of sodium-iron phosphate glasses SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article ID PHOSPHORUS OXYNITRIDE GLASSES; NUCLEAR WASTE; MOSSBAUER; NITROGEN; FE-57 AB Selected properties of phosphate glasses, containing from 14 to 43 mol% Fe2O3 and up to 13 mol% Na2O have been measured. With increasing Fe2O3 and Na2O content, the density and dilatometric softening temperature increased, whereas, the thermal expansion coefficient and dissolution rate in water or saline at 90 degrees C decreased. Glasses containing more than 25 mol% Fe2O3 had an exceedingly good chemical durability. Their dissolution rate at 90 degrees C in distilled water or in saline solution was up to 100 times lower than that of window glass. Mossbauer and X-ray photoelectron spectroscopy indicate that iron(II) and iron(III) were both present in the glasses and the chemical durability improved with increasing iron(III) concentration, The outstanding chemical durability of these glasses was attributed to the replacement of P-O-P bonds by more chemically resistant P-O-Fe(II) and P-O-Fe(III) bonds. C1 UNIV MISSOURI,DEPT CERAM ENGN,ROLLA,MO 65409. UNIV MISSOURI,DEPT CHEM,ROLLA,MO 65409. UNIV MISSOURI,GRAD CTR MAT RES,ROLLA,MO 65409. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. MINIST LIGHT IND PEOPLES REPUBL CHINA,GLASS & ENAMEL RES INST,SHANGHAI 200052,PEOPLES R CHINA. NR 25 TC 190 Z9 196 U1 4 U2 34 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD JUL PY 1997 VL 215 IS 1 BP 21 EP 31 DI 10.1016/S0022-3093(97)00022-7 PG 11 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA XK579 UT WOS:A1997XK57900003 ER PT J AU Hayes, TA Kassner, ME Amick, D Rosen, RS AF Hayes, TA Kassner, ME Amick, D Rosen, RS TI The thermal stability of surface deformed zirconium SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article ID ALPHA-ZR; DIFFUSION AB This study examined the microstructural and mechanical changes in shot-peened zirconium resulting from extended exposures to temperatures between 200 and 300 degrees C. The peening hardens the surface region which extends to about 300 mu m from the surface. It was discovered that the outermost (10-50 mu m) shot-peened surface decreases in hardness from approximately 230 VHN (DPH) to about 220 VHN after 560 h at 200 degrees C. The same drop in hardness was observed after about 5.5 h at 300 degrees C. Further drops in hardness with time were observed at 300 degrees C to a minimum surface hardness of 206 VHN after 560 h. Longer times at 200 and 300 degrees C did not appear to significantly affect the hardness. These decreases in hardness were determined from hardness depth profiles before and after heat treating the zirconium to various times from 0.5 to 4458 h. The hardness between 150 and 300 mu m (the less deformed region) was approximately unaffected by the thermal treatments, The grain dislocation structure of the shot-peened zirconium was examined in the as-peened as well as the annealed conditions using polarized light optical and transmission electron microscopy. These observations are consistent with an explanation of decreased hardness based on static recovery without any static recrystallization. (C) 1997 Elsevier Science B.V. C1 OREGON STATE UNIV,DEPT MECH ENGN,CORVALLIS,OR 97331. TELEDYNE WAH CHANG,ALBANY,OR. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. NR 26 TC 4 Z9 4 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD JUL PY 1997 VL 246 IS 1 BP 60 EP 69 DI 10.1016/S0022-3115(97)00034-2 PG 10 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA XL458 UT WOS:A1997XL45800008 ER PT J AU Honda, T Bartels, HW Uckan, NA Okazaki, T Seki, Y AF Honda, T Bartels, HW Uckan, NA Okazaki, T Seki, Y TI Safety analyses for transient behavior of plasma and in-vessel components during plasma abnormal events in fusion reactor SO JOURNAL OF NUCLEAR SCIENCE AND TECHNOLOGY LA English DT Article DE ITER tokamak; plasma abnormal events; safety analysis; plasma physics; beta limit; density limit; disruption; first wall; divertor; blankets; heat transfer ID ANALYSIS CODE SYSTEM; THERMONUCLEAR EXPERIMENTAL REACTOR; PASSIVE SAFETY AB Safety analyses on plasma abnormal events have been performed using a hg-brid code of a plasma dynamics model. and a heat transfer model of in-vessel components. Several abnormal events, e.g., increase in fuelling rate, were selected for the international Thermonuclear Experimental Reactor (ITER) and transient behavior oi the plasma and the in-vessel components during the events was analysed. The physics model for safety analysis was conservatively prepared. In most cases, the plasma is terminated by a disruption or it returns to the original operation point. When the energy confinement improves by a factor of 2.0 in the steady state, which is a hypothetical assumption under the present plasma data, the maximum fusion power reaches about 3.3 GW at about 3.6 s and the plasma is terminated due to a disruption, However, the results obtained in this study show the confinement boundary of ITER can be kept almost intact during the abnormal plasma transients, as long as the cooling system works normally. Several parametric studies are needed to comprehend the overpower transient including structure behavior, since many uncertainties are connected to the filed of the plasma physics. iind, future work will need to discuss the burn control scenario considering confinement mode transition, system specifications, experimental plans and safety regulations, etc, to confirm the safety related to the plasma anomaly. C1 ITER JOINT CENT TEAM, LA JOLLA, CA 92037 USA. OAK RIDGE NATL LAB, OAK RIDGE, TN 37831 USA. JAPAN ATOM ENERGY RES INST, NAKA FUS RES ESTAB, NAKA, IBARAKI 31101, JAPAN. RP HITACHI LTD, HITACHI RES LAB, OMIKA CHO, HITACHI, IBARAKI 31912, JAPAN. NR 9 TC 3 Z9 3 U1 1 U2 2 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 2-4 PARK SQUARE, MILTON PARK, ABINGDON OR14 4RN, OXON, ENGLAND SN 0022-3131 EI 1881-1248 J9 J NUCL SCI TECHNOL JI J. Nucl. Sci. Technol. PD JUL PY 1997 VL 34 IS 7 BP 628 EP 637 DI 10.1080/18811248.1997.9733721 PG 10 WC Nuclear Science & Technology SC Nuclear Science & Technology GA XU223 UT WOS:A1997XU22300003 ER PT J AU Altschuler, EL Hud, NV Mazrimas, JA Rupp, B AF Altschuler, EL Hud, NV Mazrimas, JA Rupp, B TI Random coil conformation for extended polyglutamine stretches in aqueous soluble monomeric peptides SO JOURNAL OF PEPTIDE RESEARCH LA English DT Article DE polyglutamine; Huntington's disease; Huntington; trinucleotide repeats ID GLUTAMINE; REPEATS AB Several neurodegenerative diseases have been found to be strongly associated with proteins containing a polyglutamine stretch which is greatly expanded from approximately 20 glutamines in normal individuals to more than 40 in affected individuals. A conformational change in the expanded polyglutamine stretch has been suggested to form the molecular basis for disease onset. Model peptides containing polyglutamine tend to aggregate and become insoluble. We have synthesized readily water-soluble monomeric peptides by flanking polyglutamine stretches with sequences rich in alanine and lysine. Circular dichroism measurements show that polyglutamine stretches of length 9 or 17 adopt a random coil configuration in aqueous solution. We think that in the disease-associated peptides for normal individuals the stretches of similar to 20 glutamines are in a random coil conformation, whereas in affected individuals the polyglutamine stretch may be in some other conformation. Our method to design soluble monomeric peptides containing extended polyglutamine stretches may be generally useful in studying other highly aggregating peptides. (C) Munksgaard 1997. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA. NR 11 TC 83 Z9 85 U1 1 U2 10 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 1397-002X J9 J PEPT RES JI J. Pept. Res. PD JUL PY 1997 VL 50 IS 1 BP 73 EP 75 PG 3 WC Biochemical Research Methods; Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA XP922 UT WOS:A1997XP92200009 PM 9273890 ER PT J AU Taylor, P Butler, P Nerbun, W AF Taylor, P Butler, P Nerbun, W TI Lead/acid batteries in systems to improve power quality SO JOURNAL OF POWER SOURCES LA English DT Article; Proceedings Paper CT 5th European Lead Battery Conference CY OCT 02-04, 1996 CL BARCELONA, SPAIN SP Lead Dev Assoc Int DE lead/acid batteries; sub-cycle response; integrated energy storage systems; power disturbances; power quality; advanced battery management AB Increasing dependence on computer technology is driving needs for extremely high-quality power to prevent loss of information, material, and workers' time that represent billions of dollars annually. This cost has motivated commercial and Federal research and development of energy storage systems that detect and respond to power-quality failures in milliseconds. Electrochemical batteries are among the storage media under investigation for these systems, Battery energy storage systems that employ either flooded lead/acid or valve-regulated lead/acid battery technologies are becoming commercially available to capture a share of this emerging market. Cooperative research and development between the US Department of Energy and private industry have led to installations of lead/acid-based battery energy storage systems to improve power quality at utility and industrial sites and commercial development of fully integrated, modular battery energy storage system products for power quality. One such system by AC Battery Corporation, called the PQ2000, is installed at a test site at Pacific Gas and Electric Company (San Ramon, CA, USA) and at a customer site at Oglethorpe Power Corporation (Tucker, GA, USA). The PQ2000 employs off-the-shelf power electronics in an integrated methodology to control the factors that affect the performance and service life of production-model, low-maintenance, flooded lead/acid batteries. This system, and other members of this first generation of lead/acid-based energy storage systems, will need to compete vigorously for a share of an expanding, yet very aggressive, power quality market. (C) 1997 Elsevier Science S.A. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. AC BATTERY CORP,E TROY,WI 53120. RP Taylor, P (reprint author), ENERGET INC,7164 GATEWAY DR,COLUMBIA,MD 21046, USA. NR 16 TC 1 Z9 1 U1 0 U2 4 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0378-7753 J9 J POWER SOURCES JI J. Power Sources PD JUL-AUG PY 1997 VL 67 IS 1-2 BP 187 EP 191 DI 10.1016/S0378-7753(97)02548-2 PG 5 WC Chemistry, Physical; Electrochemistry; Energy & Fuels; Materials Science, Multidisciplinary SC Chemistry; Electrochemistry; Energy & Fuels; Materials Science GA YE033 UT WOS:A1997YE03300024 ER PT J AU Sakaguchi, K Sakamoto, H Xie, D Erickson, JW Lewis, MS Anderson, CW Appella, E AF Sakaguchi, K Sakamoto, H Xie, D Erickson, JW Lewis, MS Anderson, CW Appella, E TI Effect of phosphorylation on tetramerization of the tumor suppressor protein p53 SO JOURNAL OF PROTEIN CHEMISTRY LA English DT Article DE p53; tumor suppressor gene; tetramerization; phosphorylation ID DNA-BINDING FUNCTION; OLIGOMERIZATION DOMAIN AB Human tumor suppresses protein p53 is a 393-amino acid phosphoprotein that enhances transcription in response to DNA damage from several genes that regulate cell cycle progression. The tetrameric state of p53 is critical to wild-type function; the p53 tetramerization element is located in the C-terminal region of the protein. This region is phosphorylated at several evolutionarily conserved serines, suggesting that phosphorylation may be an important regulator of p53 function. In order to determine the effect of phosphorylation on tetramer formation, we synthesized phosphopeptides corresponding to p53(Ser303-Asp393) with phosphate incorporated at Ser315, Ser378, or Ser392, and at both Ser315 and Ser392. Equilibrium ultracentrifugation analysis showed that phosphorylation at Ser392 increased the association constant for tetramer formation nearly ten-fold. By itself, phosphorylation at Ser315 or Ser378 had little effect on tetramer formation, but Ser315 largely reversed the effect of phosphorylation at Ser392. Analysis by calorimetry suggests that phosphorylation may influence subunit affinity by an enthalpy driven process. C1 NCI,CELL BIOL LAB,NIH,BETHESDA,MD 20892. NCI,FREDERICK CANC RES & DEV CTR,DYNCORP,STRUCT BIOCHEM PROGRAM,PRI,FREDERICK,MD 21702. NATL CTR RES RESOURCES,BIOMED ENGN & INSTRUMENTAT PROGRAM,NIH,BETHESDA,MD 20892. BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 11973. RI Sakamoto, Hiroshi/A-3181-2011 NR 12 TC 28 Z9 28 U1 1 U2 5 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0277-8033 J9 J PROTEIN CHEM JI J. Protein Chem. PD JUL PY 1997 VL 16 IS 5 BP 553 EP 556 DI 10.1023/A:1026334116189 PG 4 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA XK873 UT WOS:A1997XK87300035 PM 9246643 ER PT J AU Iglesias, CA AF Iglesias, CA TI Broadening of the Raman resonance in photon scattering in plasmas - Comment SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Editorial Material ID SOLAR INTERIOR; OPACITIES AB A recent examination of photon scattering in the solar interior by Tsytovich et al. [JQSRT 55, 787 (1996)] is shown to interpret incorrectly past calculations of the Raman resonance and Doppler shift contributions. (C) 1997 Elsevier Science Ltd. RP Iglesias, CA (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,LIVERMORE,CA 94550, USA. NR 10 TC 2 Z9 2 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD JUL PY 1997 VL 58 IS 1 BP 141 EP 143 DI 10.1016/S0022-4073(97)00047-2 PG 3 WC Optics; Spectroscopy SC Optics; Spectroscopy GA XM932 UT WOS:A1997XM93200015 ER PT J AU Zykov, MP Romanovsky, VN Wester, DW Kodina, GE Bartenev, SA Malysheva, AO Dorontchenkova, TN Usatcheva, NT Antonjuk, AV Sviridov, BD AF Zykov, MP Romanovsky, VN Wester, DW Kodina, GE Bartenev, SA Malysheva, AO Dorontchenkova, TN Usatcheva, NT Antonjuk, AV Sviridov, BD TI Preparation of a ready-for-injection radiopharmaceutical based on MIBI using Tc-99m from a centralized extraction generator SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Letter AB A modified method for synthesizing MIBI is described. A ready-for-injection using the synthesized MIBI is prepared. The Tc-99m source is a centralized extraction generator. C1 PACIFIC NW LAB, RICHLAND, WA 99352 USA. MINIST PUBL HLTH RUSSIA, INST BIOPHYS, MOSCOW, RUSSIA. RP Zykov, MP (reprint author), VG KHLOPIN RADIUM INST, 2ND MURINSKY AV 28, ST PETERSBURG 194021, RUSSIA. NR 9 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD JUL PY 1997 VL 221 IS 1-2 BP 227 EP 229 DI 10.1007/BF02035274 PG 3 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA YA477 UT WOS:A1997YA47700041 ER PT J AU Ismunandar Kennedy, BJ Hunter, BA Vogt, T AF Ismunandar Kennedy, BJ Hunter, BA Vogt, T TI Bonding and structural variations in doped Bi2Sn2O7 SO JOURNAL OF SOLID STATE CHEMISTRY LA English DT Article ID POWDER DIFFRACTOMETER; BISMUTH PYROCHLORES; VALENCE PARAMETERS; CATALYSTS; DIFFRACTION; OXIDATION; OXIDES; SOLIDS AB The structural properties of Y-doped Bi2Sn2O7 have been determined by Rietveld analysis of powder neutron and synchrotron X-ray diffraction data, These materials form a series of cubic pyrochlore-type oxides with a distinct miscibility gap at low Bi contents and show lame deviations from Vegards law, Temperature-dependent structural studies of (BiY)Sn2O7 and (BiYb) Sn2O7 have been undertaken. The structure of the high temperature, pyrochlore phase of Bi2Sn2O7 has been refined using powder neutron diffraction data. The evolution of the charge density on the Bi site has been probed using a combination of bond valence sum calculations and electronic spectroscopy. (C) 1997 Academic Press. C1 AUSTRALIAN NUCL SCI & TECHNOL ORG, MENAI, NSW 2234, AUSTRALIA. BROOKHAVEN NATL LAB, DEPT PHYS, UPTON, NY 11973 USA. RP Ismunandar (reprint author), UNIV SYDNEY, SCH CHEM, SYDNEY, NSW 2006, AUSTRALIA. RI Vogt, Thomas /A-1562-2011; Ismunandar, -/D-6838-2011; OI Vogt, Thomas /0000-0002-4731-2787; Kennedy, Brendan/0000-0002-7187-4579 NR 44 TC 14 Z9 14 U1 1 U2 24 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0022-4596 J9 J SOLID STATE CHEM JI J. Solid State Chem. PD JUL PY 1997 VL 131 IS 2 BP 317 EP 325 DI 10.1006/jssc.1997.7387 PG 9 WC Chemistry, Inorganic & Nuclear; Chemistry, Physical SC Chemistry GA XQ330 UT WOS:A1997XQ33000016 ER PT J AU Kleinke, H Franzen, HF AF Kleinke, H Franzen, HF TI Structure and properties of the new phosphides M2M'P ((M=Zr, Hf; M'=Co, Ni) and their relations to ZrNi and HfNi SO JOURNAL OF SOLID STATE CHEMISTRY LA English DT Article ID CRYSTAL-STRUCTURE; FE2TA9S6; CO2TA9S6; CLUSTERS AB The isostructural title compounds can be obtained by arc-melting of cold-pressed mixtures of MP, M, and M' in the ratio 1:1:1 (M = Zr, Hf; M' = Co, Ni). Their crystal structure (space group P2(1)/m, No. 11, Z = 2) can be regarded as a new superstructure of the CrB structure type. Thus, the structure of M2NiP can be derived formally from ZrNi or HfNi (both CrB type) by replacing every second Ni atom by P in such a way that P-P contacts are minimized. Condensed channels formed by zirconium and hafnium, respectively, build up an extended early-transition-metal framework. The late-transition-metal atoms and P are situated in singly capped trigonal prisms of the M sublattice, forming -NiP- zigzag chains. The expectation of metallic properties is confirmed by Extended Huckel calculations and experimentally observed Pauli paramagnetism. The differences between Co and Ni on the one hand and between Zr and Hf on the other hand are discussed, as well as the changes from MNi to M2NiP. (C) 1997 Academic Press. RP Kleinke, H (reprint author), IOWA STATE UNIV,AMES LAB,US DOE,AMES,IA 50011, USA. NR 24 TC 8 Z9 8 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 JUL PY 1997 VL 131 IS 2 BP 379 EP 386 DI 10.1006/jssc.1997.7405 PG 8 WC Chemistry, Inorganic & Nuclear; Chemistry, Physical SC Chemistry GA XQ330 UT WOS:A1997XQ33000025 ER PT J AU Novak, CF AlMahamid, I Becraft, KA Carpenter, SA Hakem, N Prussin, T AF Novak, CF AlMahamid, I Becraft, KA Carpenter, SA Hakem, N Prussin, T TI Measurement and thermodynamic modeling of Np(V) solubility in aqueous K2CO3 solutions to high concentrations SO JOURNAL OF SOLUTION CHEMISTRY LA English DT Article DE neptunium (V); thermodynamics; solubility; concentrated electrolytes; Pitzer activity coefficient expressions AB The solubility of Np(V) solids was studied in 0.01 to 6.38 mol-kg(-1) K2CO3 solutions. Two series of experiments were conducted from undersaturation using NpO2OH(s) or KNpO2CO3(s) as the starting solid. The Np(V) solid phases observed at steady state are KNpO2CO3(s) and K3NpO2(CO3)(2)(s). The activity coefficient formalism of Fitter was used to obtain a thermodynamic interpretation of these data, including the solubility constants: KNpO2CO3(s) reversible arrow K+ + NpO2+ + CO32- log K-s = -13.6+/-0.1(2 sigma) K3NpO2(CO3)(2)(s) reversible arrow 3K(+) + NpO2+ + 2CO(3)(2-) log K-s = -15.9+/-0.1(2 sigma) To model these data, we propose values for several binary and ternary ion interaction parameters among the carbonate ion, potassium ion, and the neptunyl triscarbonato ion. With these new parameters, the thermodynamic data base for Np(V) solubility in concentrated aqueous solutions has been extended to the Na-K-Cl-ClO4-CO3-H-OH-H2O system. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. LAWRENCE BERKELEY NATL LAB,BERKELEY,CA. NR 17 TC 7 Z9 7 U1 0 U2 3 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0095-9782 J9 J SOLUTION CHEM JI J. Solut. Chem. PD JUL PY 1997 VL 26 IS 7 BP 681 EP 697 DI 10.1007/BF02767621 PG 17 WC Chemistry, Physical SC Chemistry GA YA786 UT WOS:A1997YA78600003 ER PT J AU Seegers, JC Lottering, ML Grobler, CJS vanPapendorp, DH Habbersett, RC Shou, YL Lehnert, BE AF Seegers, JC Lottering, ML Grobler, CJS vanPapendorp, DH Habbersett, RC Shou, YL Lehnert, BE TI The mammalian metabolite, 2-methoxyestradiol, affects p53 levels and apoptosis induction in transformed cells but not in normal cells SO JOURNAL OF STEROID BIOCHEMISTRY AND MOLECULAR BIOLOGY LA English DT Article ID INHIBITS TUBULIN POLYMERIZATION; HUMAN FIBROBLASTS; CYCLE SPECIFICITY; DNA-DAMAGE; T-ANTIGEN; RADIATION; LINES; CAMPTOTHECIN; ACTIVATION; GROWTH AB The endogenous metabolite, 2-methoxyestradiol (2ME), is an inhibitor of tubulin polymerization and is therefore toxic to dividing fast-growing tumor cells. Transformed cells are not equally susceptible to the effects of 2ME. In this study the effects of 1-2 mu M doses of 2ME on cell cycle progression, apoptosis induction and on p53 levels were evaluated using flow cytometry in cells with different p53 status. No effect of 2ME was seen in normal human skin fibroblast strain HSF43 with wild-type (wt) p53. However, in SV40 T antigen transformed HSF43 cells (line E8T4), 2ME caused a prominent G(2)/M arrest, with subsequent micronuclei formation followed by apoptosis. Increased p53 levels were present in the G(2)/M cells. Our results suggest that 2ME, being a microtubule poison, may release the bound p53 from T antigen, and that this p53 may enhance the apoptotic effects. Two lymphoblast cell lines derived from the same donor, TK6, expressing low levels of wt p53, and WTK1, expressing high levels of mutant p53, showed similar moderate responses to 2ME at 37 degrees C. The effects included enhanced apoptosis and a modest G(2)/M block. No increase in p53 levels was seen. However, at the permissive temperature of 30 degrees C marked increases in apoptosis and a prominent G(2)/M-phase block, similar to that seen in the E8T4 cells, were present in the WTK1 cells, indicating that the high levels of mutant p53 have now become functional, enhancing the apoptotic effects initiated by 2ME. (C) 1997 Elsevier Science Ltd. C1 LOS ALAMOS NATL LAB,CYTOMETRY & CELL GRP,LOS ALAMOS,NM. LOS ALAMOS NATL LAB,DIV LIFE SCI,MOL BIOL GRP,LOS ALAMOS,NM. RP Seegers, JC (reprint author), UNIV PRETORIA,DEPT PHYSIOL,ZA-0002 PRETORIA,SOUTH AFRICA. FU PHS HHS [P41-RK-01315-20] NR 43 TC 91 Z9 91 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0960-0760 J9 J STEROID BIOCHEM JI J. Steroid Biochem. Mol. Biol. PD JUL PY 1997 VL 62 IS 4 BP 253 EP 267 DI 10.1016/S0960-0760(97)00043-5 PG 15 WC Biochemistry & Molecular Biology; Endocrinology & Metabolism SC Biochemistry & Molecular Biology; Endocrinology & Metabolism GA YK980 UT WOS:A1997YK98000003 PM 9408079 ER PT J AU Wang, X Grush, MM Froeschner, AG Cramer, SP AF Wang, X Grush, MM Froeschner, AG Cramer, SP TI High-resolution X-ray fluorescence and excitation spectroscopy of metalloproteins SO JOURNAL OF SYNCHROTRON RADIATION LA English DT Article DE X-ray fluorescence; kappa beta emission; spin polarization; metalloproteins ID OXYGEN-EVOLVING COMPLEX; WIGGLER BEAM LINE; ABSORPTION-SPECTROSCOPY; PYROCOCCUS-FURIOSUS; MANGANESE CLUSTER; EDGE; PERFORMANCE; SCATTERING; EMISSION; STATE AB A spectrograph has been developed with sufficient efficiency to make high-resolution fluorescence experiments on metalloproteins possible. The resolution of this spectrometer can reach 0.45 eV at 7.1 keV emission energy. The focus images of this multiple curved-crystal array spectrometer are presented. The chemical sensitivity of K beta emission spectra can be used to identify chemical states, and the spin-polarized near-edge structure provides a new measure of the spin density. The high-resolution fluorescence metalloprotein studies should become routine with third-generation synchrotron facilities, and the strength of both site and spin selectivity should complement the structural information from other spectroscopies. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV ENERGY & ENVIRONM,BERKELEY,CA 94720. RP Wang, X (reprint author), UNIV CALIF DAVIS,DEPT APPL SCI,DAVIS,CA 95616, USA. NR 55 TC 29 Z9 30 U1 0 U2 6 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0909-0495 J9 J SYNCHROTRON RADIAT JI J. Synchrot. Radiat. PD JUL 1 PY 1997 VL 4 BP 236 EP 242 DI 10.1107/S0909049596015440 PN 4 PG 7 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA XL412 UT WOS:A1997XL41200008 PM 16699236 ER PT J AU Johnston, RG AF Johnston, RG TI Effective vulnerability assessment of tamper-indicating seals SO JOURNAL OF TESTING AND EVALUATION LA English DT Article DE security seals; tamper-indicating seals; tamper-indicating devices; tamper-evident devices; tamper detection; tags; antipilferage AB Security seals are widely used to detect tampering or unauthorized entry. In the author's view, existing standards for vulnerability assessment of security seals are incomplete. This paper discusses the critical attributes of effective vulnerability assessment. These include: a clear understanding of what seal vulnerability assessment is and why it is undertaken; use of appropriate assessment personnel; assessment at the earliest possible stage of seal development; analysis conducted with the proper emphasis and context; rejection of findings of zero vulnerabilities; avoidance of the term ''tamper-proof''; characterization of the degree of defeat; and thorough reporting of findings. RP Johnston, RG (reprint author), LOS ALAMOS NATL LAB,ADV CHEM DIAGNOST & INSTRUMENTAT GRP,CHEM SCI & TECHNOL DIV,LOS ALAMOS,NM 87545, USA. NR 12 TC 1 Z9 1 U1 0 U2 1 PU AMER SOC TESTING MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DR, W CONSHOHOCKEN, PA 19428-2959 SN 0090-3973 J9 J TEST EVAL JI J. Test. Eval. PD JUL PY 1997 VL 25 IS 4 BP 451 EP 455 PG 5 WC Materials Science, Characterization & Testing SC Materials Science GA XR787 UT WOS:A1997XR78700013 ER PT J AU Gu, BL Nihei, KT Myer, LR AF Gu, BL Nihei, KT Myer, LR TI Numerical investigation of fracture interface waves SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article AB Two-dimensional boundary element simulations are conducted to investigate the properties of Rayleigh-type fracture interface waves generated by a line source located near a single fracture The fracture is modeled as a displacement-discontinuity boundary condition between two elastic half-spaces with identical properties, Numerical simulations are performed for different fracture stiffnesses, source polarizations. and source depths. Symmetric and antisymmetric fracture interface waves are observed with amplitudes and velocities that are controlled by the ratio of the fracture impedance to the half-space shear wave impedance. as predicted bq plane-wave theory [Gu et al., J. Geophys. Res. 101, 827-835 (1996); Pyrak-Nolte and Cook, Geophys. Res. Lett. 14, 1107-1110 (1987)]. When the source is located off the fracture, these waves develop at incidence angles that decrease with source depth. RP Gu, BL (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV EARTH SCI,1 CYCLOTRON RD,MS 90-1116,BERKELEY,CA 94720, USA. RI Nihei, Kurt/K-1239-2016 NR 12 TC 4 Z9 4 U1 0 U2 1 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 JUL PY 1997 VL 102 IS 1 BP 120 EP 127 DI 10.1121/1.419769 PG 8 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA XL752 UT WOS:A1997XL75200012 ER PT J AU Mitchell, TE Lu, YC Griffin, AJ Nastasi, M Kung, H AF Mitchell, TE Lu, YC Griffin, AJ Nastasi, M Kung, H TI Structure and mechanical properties of copper/niobium multilayers SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article; Proceedings Paper CT Symposium on Microstructure/Properties Relations of Advanced Materials CY APR 29-30, 1996 CL MAX PLANCK INST METALFORSCH, STUTTGART, GERMANY SP Max Planck Gesell Forder Wissensch (Max Planck Soc Promot Sci), Max Planck Inst Metallforsch HO MAX PLANCK INST METALFORSCH ID COPPER; MICROSTRUCTURE; FILMS AB Copper/niobium multilayers prepared by sputtering onto Si substrates with layer thicknesses ranging from 11 to 5000 Angstrom have been characterized by transmission electron microscopy and nanoindentation. The films are strongly textured with {110} close-packed planes of the bcc Nb parallel to the {111} close-packed planes of the fcc Cu and close-packed directions tending to be parallel as well. For the 11 Angstrom layers, the Cu is found to grow pseudomorphically on Nb in the bcc structure. It is thought that, for thicker layers, the bcc Cu loses coherency and transforms martensitically to the fcc phase, thus resulting in the observed Kurdjumov-Sachs orientation relationship. As the layer thickness, d, decreases from 5000 to 500 Angstrom, the hardness increases as d(-1/2); i.e., it follows a Hall-Petch relationship so that hardening is due to grain boundaries and interfaces. The slope is the same as in pure Cu, but there is a large intercept which is ascribed to internal stresses and a large dislocation density. As the layer thickness decreases from 100 to 11 Angstrom, the hardness increases as (1/d) ln (0.69d), which is a line tension formulation such as would be expected for Orowan dislocation bowing between the layers. Again there is a large intercept which is ascribed to cutting through the Cu/Nb interfaces. The interfacial energy is calculated to be 0.46 J/m(2). RP Mitchell, TE (reprint author), LOS ALAMOS NATL LAB, CTR MAT SCI, LOS ALAMOS, NM 87545 USA. NR 18 TC 56 Z9 56 U1 3 U2 16 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD JUL PY 1997 VL 80 IS 7 BP 1673 EP 1676 PG 4 WC Materials Science, Ceramics SC Materials Science GA XK874 UT WOS:A1997XK87400008 ER PT J AU Danan, F Chen, LQ AF Danan, F Chen, LQ TI Computer simulation of grain growth and Ostwald ripening in alumina-zirconia two-phase composites SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article; Proceedings Paper CT 98th Annual Meeting of the American-Ceramic-Society CY APR 14-17, 1996 CL INDIANAPOLIS, IN SP Amer Ceram Soc ID MICROSTRUCTURAL EVOLUTION; CERAMICS; PARTICLES; KINETICS; AL2O3 AB The kinetics of grain growth and Ostwald ripening in Al2O3-ZrO2 two-phase composites was systematically investigated using two-dimensional (2-D) computer simulations, based on a diffuse-interface field model. Using average values for the experimentally measured ratios of the grain boundary energies to the interphase boundary energy as the input, the predicted 2-D microstructural features and their evolution are in excellent qualitative agreement with experimental observations on 2-D cross sections of 3-D Al2O3-ZrO2 two-phase composite microstructures. It was found that the coupled grain growth in Al2O3-ZrO2 composites is controlled by long-range diffusion and the average size (R-t) as a function of time (t) follows the power-growth law, R-t(m) - R-0(m) = kt with m = 3, which is independent of the initial microstructures and volume fractions of the two phases. The predicted variation of the kinetic coefficient (k) on the volume fraction follows a trend similar to that experimentally measured through the entire range of volume fractions. The scaling of grain size distributions is observed at a given volume fraction, i.e., they are time-invariant in the steady state, However, the characteristics of size distributions vary with the initial microstructures and the volume fractions. The relationship between matrix grain size and second-phase grain size is discussed. RP LOS ALAMOS NATL LAB, T-11, MS B262, LOS ALAMOS, NM 87545 USA. NR 27 TC 2 Z9 2 U1 3 U2 7 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 JUL PY 1997 VL 80 IS 7 BP 1773 EP 1780 PG 8 WC Materials Science, Ceramics SC Materials Science GA XK874 UT WOS:A1997XK87400022 ER PT J AU Drummond, JL Steinberg, AD Krauss, AR AF Drummond, JL Steinberg, AD Krauss, AR TI X-ray photoemission and energy dispersive spectroscopy of hydroxyapatite-coated titanium SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article; Proceedings Paper CT Annual Meeting of the American-Association-of-Dental-Research CY MAR 08-12, 1995 CL SAN ANTONIO, TX SP Amer Assoc Dent Res ID BONDING BEHAVIOR; SURFACE; GLASS; BONE AB The purpose of this study was to determine the chemical composition changes of hydroxyapatite (HA) coated titanium using surface analysis (X-ray photoemission) and bulk analysis (energy dispersive spectroscopy), The specimens examined were controls and specimens aged 30 min and 3 h at room temperature in distilled water and 0.2M sodium phosphate buffer (pH 7.2), Each X-ray photoemission cycle consisted of three scans followed by argon sputtering for 10 min for usually 20 cycles, corresponding to a sampling depth of similar to 1500 Angstrom. The energy dispersive spectroscopy analysis was on a 110 by 90 mu m area for 500 s. The X-ray photoemission results indicated the oxidation effect of water on the titanium (as TiO2) and the effect of the buffer to increase the surface concentration of phosphorus. No differences in the chemical composition were observed by energy dispersive spectroscopy analysis. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. RP Drummond, JL (reprint author), UNIV ILLINOIS,COLL DENT,CHICAGO,IL 60612, USA. NR 12 TC 4 Z9 4 U1 0 U2 3 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 JUL PY 1997 VL 80 IS 7 BP 1868 EP 1872 PG 5 WC Materials Science, Ceramics SC Materials Science GA XK874 UT WOS:A1997XK87400033 ER PT J AU Kim, HE Moorhead, AJ Kim, SH AF Kim, HE Moorhead, AJ Kim, SH TI Strengthening of alumina by formation of a mullite/glass layer on the surface SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID PARTICULATE COMPOSITES; SILICON-CARBIDE; STRESS PROFILES; INFILTRATION; OXIDATION; CORROSION; ATMOSPHERES; CERAMICS; H2-H2O AB A layer composed of mullite and silicate glass was caused to form on the surface of a high-purity alumina ceramic in order to enhance the strength of the material. The layer was formed by exposing the specimens above a bed of SiC platelets at 1400 degrees C to a flowing H-2 atmosphere containing similar to 0.1% H2O. A reaction between the SiC platelets and the H2O in the environment resulted in the generation of SiO gas, Some of the SiO gas subsequently reacted with ambient H2O in the atmosphere, forming SiO2 ''smoke'' which was deposited on, and reacted with, the alumina substrate, The strength of the ceramic was significantly improved by the reaction layer, which was found to be comprised of mullite and silicate glass. The increases in strength (about 60% above that of the material in the ''as-polished'' condition) was attributed to the blunting of surface cracks. A similar strengthening effect was observed in samples of the material which had been ground with a 220-grit diamond abrasive,wheel (as had all of the samples) but not polished. C1 OAK RIDGE NATL LAB,DIV MET & CERAM,OAK RIDGE,TN 37831. RP Kim, HE (reprint author), SEOUL NATL UNIV,DEPT INORGAN MAT ENGN,SEOUL 151742,SOUTH KOREA. NR 21 TC 12 Z9 13 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 JUL PY 1997 VL 80 IS 7 BP 1877 EP 1880 PG 4 WC Materials Science, Ceramics SC Materials Science GA XK874 UT WOS:A1997XK87400035 ER PT J AU Mason, JD AF Mason, JD TI SGML and related standards: New directions as the second decade begins SO JOURNAL OF THE AMERICAN SOCIETY FOR INFORMATION SCIENCE LA English DT Article; Proceedings Paper CT SGML 95 Meeting CY 1995 CL BOSTON, MA AB In 1995 and early 1996, the ISO standards process that includes SGML and related standards has seen a remarkable coalescence of efforts that should be beneficial to all of us. Most notably, DSSSL and HyTime are developing a shared approach to tree structures and query languages. A consequence of this may be the development of a set of general facilities that can be shared among all SGML-based standards and that, when incorporated into products, will make our documents easier to work with and more powerful in their ability to deliver information. RP Mason, JD (reprint author), OAK RIDGE NATL LAB,LOCKHEED MARTIN ENERGY SYST,BLDG 2506,MS 6302,OAK RIDGE,TN 37831, USA. NR 0 TC 0 Z9 0 U1 1 U2 2 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0002-8231 J9 J AM SOC INFORM SCI JI J. Am. Soc. Inf. Sci. PD JUL PY 1997 VL 48 IS 7 BP 593 EP 596 PG 4 WC Computer Science, Information Systems; Information Science & Library Science SC Computer Science; Information Science & Library Science GA XG194 UT WOS:A1997XG19400005 ER PT J AU Gill, CG Garrett, AW Earl, WL Nogar, NS Hemberger, PH AF Gill, CG Garrett, AW Earl, WL Nogar, NS Hemberger, PH TI Modified zeolites for mass spectral analysis of tributyl phosphate using in situ silver ion chemical ionization SO JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY LA English DT Article ID SOLID-PHASE MICROEXTRACTION; LASER; SPECTROMETRY; SPECTROSCOPY; CHEMISTRY AB The use of silver ion exchanged zeolites for the sampling al-id subsequent analysis of tributyl phosphate (TBP) by laser desorption-mass spectrometry is presented. This technique, which should be generally applicable to any organic molecule that undergoes facile reaction with metal cations, uses silver counter ions in the zeolites as chemical ionization reagent ions to form metal cationized pseudomolecular ions of tl-Le molecule sorbed by the zeolite. Resonant laser ablation was used to selectively generate Ag+ from the zeolite sample to reduce the number of unwanted ions injected into the ion trap, although conventional desorption ionization can be used to create metal cations. The experiment is simple to implement, and provides a strong ion signal fur the Ag(TBP)(+) adduct species. Mass spectrometry/mass spectrometry provides data necessary for compound identification. Adsorption of TBP based upon zeolite pore size was modeled for two zeolite structures and their ability to accept TRP into their pore volumes; these computational results are strongly supported by the experimental data presented here. (C) 1997 American Society for Mass Spectrometry. C1 LOS ALAMOS NATL LAB,CHEM SCI & TECHNOL DIV,LOS ALAMOS,NM 87545. NR 23 TC 5 Z9 5 U1 0 U2 2 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 1044-0305 J9 J AM SOC MASS SPECTR JI J. Am. Soc. Mass Spectrom. PD JUL PY 1997 VL 8 IS 7 BP 718 EP 723 DI 10.1016/S1044-0305(97)00030-5 PG 6 WC Chemistry, Analytical; Chemistry, Physical; Spectroscopy SC Chemistry; Spectroscopy GA XG350 UT WOS:A1997XG35000006 ER PT J AU Johnson, CS Mansuetto, MF Thackeray, MM Shao-Horn, Y Hackney, SA AF Johnson, CS Mansuetto, MF Thackeray, MM Shao-Horn, Y Hackney, SA TI Stabilized alpha-MnO2 electrodes for rechargeable 3 V lithium batteries SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID SYSTEM; CELLS AB Manganese dioxide electrodes that have x-ray diffraction patterns characteristic of alpha-MnO2 (hollandite-type structure) and ramsdellite-MnO2 have been evaluated in rechargeable 3 V lithium cells. Electrochemical data indicate that these electrodes (162 mAh/g, 10th cycle) provide superior performance to both single-phase pure alpha-MnO2 (136 mAh/g, 10th cycle) and ramsdellite-MnO2 electrodes (113 mAh/g, 10th cycle), and comparable performance to lithia-stabilized alpha-MnO2 (0.15Li(2)O . MnO2) electrodes (153 mAh/g, 10th cycle). Transmission electron microscopy images and convergent-beam electron diffraction patterns show that the MnO2 samples consist of grains of alpha-MnO2 grains of ramsdellite-MnO2, and grains of ''interconnected'' alpha-MnO2 and ramsdellite-MnO2 which exhibit a mutual crystallographic orientation. A search is underway to find other interconnected MnO2 materials with even better cycling performance. C1 MICHIGAN TECHNOL UNIV, DEPT MAT & MET ENGN, HOUGHTON, MI 49931 USA. RP Johnson, CS (reprint author), ARGONNE NATL LAB, DIV CHEM TECHNOL, ELECTROCHEM TECHNOL PROGRAM, 9700 S CASS AVE, ARGONNE, IL 60439 USA. NR 21 TC 53 Z9 53 U1 1 U2 17 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 JUL PY 1997 VL 144 IS 7 BP 2279 EP 2283 DI 10.1149/1.1837804 PG 5 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA XM567 UT WOS:A1997XM56700014 ER PT J AU Oblonsky, LJ Davenport, AJ Ryan, MP Isaacs, HS Newman, RC AF Oblonsky, LJ Davenport, AJ Ryan, MP Isaacs, HS Newman, RC TI In situ x-ray absorption near edge structure study of the potential dependence of the formation of the passive film on iron in borate buffer SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID REDUCTION; STABILITY; KINETICS; GROWTH; OXIDES; MODEL AB The passive film formed on iron in pH 8.4, 0.136 M borate buffer over a broad potential range was characterized by in situ x-ray absorption near edge structure. On stepping the potential to a value between -0.6 and +0.4 V relative to a mercurous sulfate reference electrode (MSE), a passive film forms without detectable dissolution. Formation of a passive film at potentials between -0.8 and -0.65 V is accompanied by dissolution during the early stages of passivation. At -0.9 V, the iron did not passivate, but continued to dissolve. The valence state of iron in the film Is predominantly Fe3+ with 4 to 10% Fe2+ at high potentials (+0.4 V), and 14 to 20% Fe2+ at the lower potentials. The behavior on changing the solution concentration (pH 8.4, 0.01 M) and pH (pH 7.4, 0.1 M) was compared with passivation in the ''classical'' borate buffer (pH 8.4, 0.136 M). Passivation at +0.4 V in the modified borate buffers is associated with dissolution during the early stages of passivation, but the films that form have average oxidation states similar to these observed in pH 8.4, 0.136 M borate buffer. This indicates that the susceptibility to dissolution during passivation does not influence the valence state of the final film. C1 UNIV MANCHESTER, INST SCI & TECHNOL, MANCHESTER MAT SCI CTR, MANCHESTER M1 7HS, LANCS, ENGLAND. UNIV MANCHESTER, INST SCI & TECHNOL, CTR CORROS & PROTECT, MANCHESTER M60 1QD, LANCS, ENGLAND. RP Oblonsky, LJ (reprint author), BROOKHAVEN NATL LAB, DEPT APPL SCI, UPTON, NY 11973 USA. RI Davenport, Alison/J-6089-2013 OI Davenport, Alison/0000-0003-0853-515X NR 28 TC 70 Z9 70 U1 0 U2 10 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 JUL PY 1997 VL 144 IS 7 BP 2398 EP 2404 DI 10.1149/1.1837826 PG 7 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA XM567 UT WOS:A1997XM56700036 ER PT J AU Johannes, J Bartel, T Hebner, GA Woodworth, J Economou, DJ AF Johannes, J Bartel, T Hebner, GA Woodworth, J Economou, DJ TI Direct simulation Monte Carlo of inductively coupled plasma and comparison with experiments SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID DISCHARGE; REACTOR; MODEL; DEPOSITION; CHLORINE; FLOW AB Direct simulation Monte Carlo was used to study ion and neutral transport and reaction in a low-gas-pressure high-plasma-density inductively coupled reactor with chlorine (electronegative) chemistry. Electron density and temperature were computed by a self-consistent continuum plasma code and were used as input to the direct simulation Monte Carlo code. Simulation results were compared with experimental data taken in a Gaseous Electronics Conference reference cell modified for inductive plasma operation. Data on the radial distribution of positive ion density (Cl-), negative ion density (Cl-), as well as the energy distribution of ions bombarding the substrate electrode compared favorably with simulation results. In addition, the measured atomic chlorine density variations with pressure and power were captured by the simulation. C1 UNIV HOUSTON, DEPT CHEM ENGN, PLASMA PROC LAB, HOUSTON, TX 77204 USA. RP Johannes, J (reprint author), SANDIA NATL LABS, POB 5800, ALBUQUERQUE, NM 87185 USA. NR 32 TC 18 Z9 19 U1 0 U2 0 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 65 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD JUL PY 1997 VL 144 IS 7 BP 2448 EP 2455 DI 10.1149/1.1837835 PG 8 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA XM567 UT WOS:A1997XM56700045 ER PT J AU Rothenberg, JE AF Rothenberg, JE TI Comparison of beam-smoothing methods for direct-drive inertial confinement fusion SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID GLASS LASER SYSTEM; INSTABILITY; INCOHERENCE; UNIFORMITY; LIGHT AB Analysis and numerical simulations of the smoothing of the speckled illumination of a direct-drive inertial confinement fusion target are presented. In particular, the spatial spectrum of the integrated target fluence is compared across smoothing methods. Two categories of smoothing methods are considered. In one method spatially incoherent light is amplified and directed onto the target, whereas in the other the light is phase modulated and spectrally dispersed before being amplified and then focused through a random phase plate onto the target. The dependence of the smoothed spatial spectrum on the characteristics of phase modulation and dispersion is examined for both sinusoidal and more general phase modulation. It is shown that smoothing with nonsinusoidal phase modulation can result in spatial spectra that are substantially identical to that obtained with the incoherent light method in which random phase plates are present in both methods and identical beam divergence is assumed. (C) 1997 Optical Society of America. RP Rothenberg, JE (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,L-439,LIVERMORE,CA 94551, USA. NR 20 TC 70 Z9 72 U1 2 U2 5 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 JUL PY 1997 VL 14 IS 7 BP 1664 EP 1671 DI 10.1364/JOSAB.14.001664 PG 8 WC Optics SC Optics GA XL999 UT WOS:A1997XL99900017 ER PT J AU Burtsev, S Camassa, R AF Burtsev, S Camassa, R TI Nonadiabatic dynamics of dark solitons SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID OPTICAL FIBERS; PERTURBATION-THEORY; TRANSMISSION; PROPAGATION; DISPERSION; GENERATION; PULSES; JITTER; MEDIA AB We show that under certain conditions the dark-soliton solutions of the defocusing nonlinear Schrodinger equation can be less stable than their bright counterparts. This is due to the tendency of a dark soliton under external perturbation to generate dispersive waves that organize themselves into a shelf around the pulse wings, as exemplified by the simple case of dark solitons under small linear damping or amplification. The shelf generation is a nonadiabatic process: The shelf area is of order unity after a propagation distance that scales as the inverse of the perturbation magnitude. This is in contrast with the bright-soliton dynamics under similar circumstances. We analyze the effect of this extra source of dispersive waves on possible dark-soliton-based long-distance communication systems. me find that the second-order (in the normalized amplifier spacing) perturbation that results from averaging does not lead to shelf formation, whereas a control device in general causes it, unless the controller parameters are chosen according to a simple criterion aimed at suppressing dispersive wave generation. We illustrate the effectiveness of this criterion with extensive numerical simulations. (C) 1997 Optical Society of America. C1 LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES,LOS ALAMOS,NM 87545. RP Burtsev, S (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. NR 30 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 JUL PY 1997 VL 14 IS 7 BP 1782 EP 1787 DI 10.1364/JOSAB.14.001782 PG 6 WC Optics SC Optics GA XL999 UT WOS:A1997XL99900034 ER PT J AU Gabitov, I Holm, DD Luce, BP AF Gabitov, I Holm, DD Luce, BP TI Low-noise picosecond soliton transmission by use of concatenated nonlinear amplifying loop mirrors SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article AB We compare two systems that are specially configured with loop mirrors to provide stable picosecond soliton transmission. One configuration, created by Smith and Doran [J. Opt. Sec. Am. B 12, 1117 (1995)], uses nonlinear optical loop mirrors. This configuration is compared with another that uses nonlinear amplifying loop mirrors, the configuration of which we systematically determine from the amplitude and the pulse-width switching characteristics of the nonlinear optical loop mirror. It is found that the nonlinear optical loop mirror configuration allows stable pulse transmission with much less dispersive background waves than does the nonlinear optical loop mirror configuration. This clean performance is obtained at the cost of slightly lessening the parameter region of global stability of pulses. A technique for accurately estimating the region of global stability for amplitude and pulse-width perturbations of the stable pulse is also given. (C) 1997 Optical Society of America. C1 LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES,LOS ALAMOS,NM 87545. LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. RP Gabitov, I (reprint author), LD LANDAU THEORET PHYS INST,KOSYGINA 2,MOSCOW 117940,RUSSIA. OI Holm, Darryl D/0000-0001-6362-9912 NR 6 TC 11 Z9 11 U1 0 U2 2 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 JUL PY 1997 VL 14 IS 7 BP 1850 EP 1855 DI 10.1364/JOSAB.14.001850 PG 6 WC Optics SC Optics GA XL999 UT WOS:A1997XL99900043 ER PT J AU Yamana, M Nishimori, H Kadowaki, T Sherrington, D AF Yamana, M Nishimori, H Kadowaki, T Sherrington, D TI High-temperature dynamics of spin glasses SO JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN LA English DT Article DE dynamics; SK model; +/-J model; dynamical probability distribution function; high-temperature expansion; CLS theory ID MODEL AB We develop a systematic expansion method of physical quantities for the SK model and the finite-dimensional +/-J model of spin glasses in non-equilibrium states. The dynamical probability distribution function is derived from the master equation using a high temperature expansion. We calculate the expectation values of physical quantities from the dynamical probability distribution function, The theoretical curves show satisfactory agreement with Monte Carlo simulation results in the appropriate temperature and time regions. A comparison is made with the results of a dynamics theory by Goolen, Laughton and Sherrington. C1 UNIV OXFORD, DEPT PHYS, OXFORD OX1 3NP, ENGLAND. LOS ALAMOS NATL LAB, CTR NONLINEAR STUDIES, LOS ALAMOS, NM 87545 USA. RP Yamana, M (reprint author), TOKYO INST TECHNOL, DEPT PHYS, MEGURO KU, TOKYO 152, JAPAN. NR 9 TC 2 Z9 2 U1 0 U2 0 PU PHYSICAL SOC JAPAN PI TOKYO PA YUSHIMA URBAN BUILDING 5F, 2-31-22 YUSHIMA, BUNKYO-KU, TOKYO, 113-0034, JAPAN SN 0031-9015 J9 J PHYS SOC JPN JI J. Phys. Soc. Jpn. PD JUL PY 1997 VL 66 IS 7 BP 1962 EP 1975 DI 10.1143/JPSJ.66.1962 PG 14 WC Physics, Multidisciplinary SC Physics GA XP094 UT WOS:A1997XP09400026 ER PT J AU DelplanckeOgletree, MP Monteiro, OR AF DelplanckeOgletree, MP Monteiro, OR TI Deposition of titanium carbide films from mixed carbon and titanium plasma streams SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A LA English DT Article ID VACUUM-ARC PLASMAS; FILTERS AB Dual source metal plasma immersion ion implantation and deposition was used to deposit TixCy films over a wide range of Ti:C composition. This technique is well adapted for this purpose and allows one to tailor the microstructure and properties of the films. We investigated the variation of the composition, bonding states, and structure as functions of the deposition conditions. Excess carbon and contamination oxygen are incorporated in the TiC lattice interstitially and substitutionally, respectively. The wear mechanism of a stoichiometric TiC film was investigated and compared to that of a diamondlike carbon film. TiC fails by wear and microcrack propagation. (C) 1997 American Vacuum Society. C1 UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA. FREE UNIV BRUSSELS, DEPT MET ELECTROCHIM, B-1050 BRUSSELS, BELGIUM. NR 22 TC 31 Z9 33 U1 0 U2 0 PU A V S AMER INST PHYSICS PI MELVILLE PA STE 1 NO 1, 2 HUNTINGTON QUADRANGLE, MELVILLE, NY 11747-4502 USA SN 0734-2101 EI 1520-8559 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A PD JUL-AUG PY 1997 VL 15 IS 4 BP 1943 EP 1950 DI 10.1116/1.580663 PG 8 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA XL335 UT WOS:A1997XL33500020 ER PT J AU Gibson, JK AF Gibson, JK TI Chemistry of actinide and lanthanide metal ions (M+) in laser ablation of dispersions of inorganic compounds in polyimide and polytetrafluoroethylene SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A LA English DT Article ID MASS-SPECTROMETRY; CLUSTER-IONS; CARBON CLUSTERS; POLYMERS; CARBIDES; FRAGMENTATION; OXIDE AB The positive ions produced during excimer laser ablation of a polyimide (PI) or polytetrafluoroethylene (PTFE) matrix containing a small concentration of a solid compound comprising an actinide (Th, U) and/or lanthanide (La, Ce, Pr, Eu, Tb, Ho, Tm, Yb, Lu) were determined by time-of-flight mass spectrometry. The polyatomic mass spectra were dominated by species of the general form, M+-L, where M+ is the actinide/lanthanide and L is some fragment ligand from the polymer. For PI, primary products were M+-CcHh with c=2 or 4 and h=0 or 1. For PTFE, the main products were generally M-f(+) with f=1 or 2. Although the studied metals are largely similar in their condensed phase chemistries, rational differences were evident in the compositions of the ablation products, which often corresponded to molecules identified in high-temperature vaporization of inorganic solids. For the M+-CcHh species, the degree of hydrogenation, i.e., h=0 or 1, consistently reflected the relative thermodynamic stabilities of the binary carbide molecules, MC2, which in turn closely correlate with those of the gaseous MO. Thus, U and Ce form especially robust monoxide and dicarbide molecules and, accordingly, produced primarily the bare dicarbide, MC2+. In contrast, the monoxides and dicarbides of Eu and Tm are relatively weakly bound and their PI ablation products incorporated hydrogen to produce more substantial yields of MC2H+. The compositions of the highly ionic metal fluorides produced from PTFE ablation reflected the relative stabilities of successive metal-ion oxidation states. For example, the yield of the difluoride ion, MF2+ (approximate to M3+F2-), relative to that of the monofluoride, MF+ (approximate to M2+F-), was found to decrease in the order, CeF2+>HoF2+>TmF2+, which is the inverse of the ordering of the +2 to +3 ionization energies: Ce0.3 mu m on the target, substrate, or in the plasma. Using this technique, we demonstrate that the mechanisms for particle generation, transport, and trapping during magnetron sputter deposition are different from the mechanisms reported in previously studied plasma etch processes, due to the inherent spatial nonuniformity of magnetically enhanced plasmas. During magnetron sputter deposition, one source of particle contamination is linked to portions of the sputtering target surface exposed to weaker plasma density. There, film redeposition induces filament or nodule growth, Sputter removal of these features is inhibited by the dependence of sputter yield on angle of incidence. These features enhance trapping of plasma particles, which then increases filament growth. Eventually the growths effectively ''short-circuit'' the sheath, causing high currents to flow through these features. This, in turn, causes mechanical failure of the growth resulting in fracture and ejection of the target contaminants into the plasma and onto the substrate. Evidence of this effect has been observed in semiconductor fabrication and storage disk manufacturing. Discovery of this mechanism in both technologies suggests it may be universal to many sputter processes. (C) 1997 American Vacuum Society. C1 MAT RES CORP,N CONGERS,NY 10920. SEAGATE PERIPHERALS DISK DIV,MILPITAS,CA 95035. RP Selwyn, GS (reprint author), LOS ALAMOS NATL LAB,DIV PHYS,M-S E526,LOS ALAMOS,NM 87545, USA. NR 19 TC 15 Z9 15 U1 0 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 JUL-AUG PY 1997 VL 15 IS 4 BP 2023 EP 2028 DI 10.1116/1.580674 PG 6 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA XL335 UT WOS:A1997XL33500031 ER PT J AU Nelson, AJ Schwerdtfeger, CR Herdt, GC King, D Contreras, M Ramanathan, K OBrien, WL AF Nelson, AJ Schwerdtfeger, CR Herdt, GC King, D Contreras, M Ramanathan, K OBrien, WL TI X-ray photoemission analysis of chemically treated I-III-VI semiconductor surfaces SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article ID CUINSE2 AB Device-grade thin-film CuInSe2 was subjected to various chemical treatments commonly used in photovoltaic device fabrication to determine the resulting microscopic surface composition/morphology and the effect on II-VI CuInSe2 heterojunction formation. HCl (38%), Br-MeOH (<1% Br), (NH4)(2)S, and NH4OH/thiourea solutions were used separately to modify the surface chemistry of the CuInSe? polycrystalline films. Scanning electron microscopy was used to evaluate the resultant surface morphology. Angle-resolved high-resolution photoemission measurements on the valence band electronic structure and Cu 2p, in 3d, Ga 2p, and Se 3d core lines were used to evaluate the chemistry of the chemically treated surfaces. CdS overlayers were then deposited on these chemically treated surfaces. Photoemission measurements were acquired to determine the resultant heterojunction valence-band discontinuity between the CdS and the chemically modified CuInSe2 surface. (C) 1997 American Vacuum Society. C1 NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401. UNIV WISCONSIN,CTR SYNCHROTRON RADIAT,STOUGHTON,WI 53589. RP Nelson, AJ (reprint author), COLORADO SCH MINES,DEPT PHYS,GOLDEN,CO 80401, USA. NR 9 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 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD JUL-AUG PY 1997 VL 15 IS 4 BP 2058 EP 2062 DI 10.1116/1.580608 PG 5 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA XL335 UT WOS:A1997XL33500036 ER PT J AU Wu, SZ Schumann, FO Willis, RF Goodman, KW Tobin, JG Carr, R AF Wu, SZ Schumann, FO Willis, RF Goodman, KW Tobin, JG Carr, R TI Magnetic dichroism effect of binary alloys using a circularly polarized x ray SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article; Proceedings Paper CT 43rd National Symposium of the American-Vacuum-Society CY OCT 12-18, 1996 CL PHILADELPHIA, PA SP Amer Vacuum Soc ID ABSORPTION-SPECTROSCOPY; BRANCHING RATIO; SUM-RULE; MULTILAYERS; FILMS AB We have studied the magnetic properties of CoNi binary alloy films with various atomic compositions using the soft x-ray magnetic circular dichroism technique. The alloy films were deposited on a single Cu(100) crystal in situ using our well established epitaxial growth technique to achieve a layer-by-layer growth and a metastable face-centered-cubic structure, with all the films exhibiting an in-plane magnetic anisotropy. The high density, circularly polarized x-ray beam was supplied by the elliptically polarizing undulator at the Stanford Synchrotron Radiation Laboratory. Utilizing the element-specific ability and nanostructure magnetization sensitivity of this technique, we were able to perform the absorption measurements at L-2 and L-3 edges of Co and Ni atoms and we observed large dichroism signals. The extraction of spin moment and orbital moment for varying elemental stoichiometry using magneo-optical sum rules is discussed. (C) 1997 American Vacuum Society. C1 LAWRENCE LIVERMORE NATL LAB,DEPT CHEM & MAT SCI,LIVERMORE,CA 94551. STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD SYNCHROTRON RADIAT LAB,STANFORD,CA 94309. RP Wu, SZ (reprint author), PENN STATE UNIV,DEPT PHYS,104 DAVEY LAB,UNIVERSITY PK,PA 16802, USA. RI Schumann, Frank /K-9364-2014; Tobin, James/O-6953-2015 NR 16 TC 7 Z9 7 U1 0 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 JUL-AUG PY 1997 VL 15 IS 4 BP 2287 EP 2290 DI 10.1116/1.580736 PG 4 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA XL335 UT WOS:A1997XL33500069 ER PT J AU Rosenwaks, Y Li, X Coutts, TJ AF Rosenwaks, Y Li, X Coutts, TJ TI Characterization of heat-treated ITO/InP solar cells SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article ID INDIUM TIN OXIDE AB The effects of heat treatments on the properties of InP/ITO junctions were studied using time resolved photoluminescence measurements, surface chemical analysis, and photo I-V characteristics. It was found that the surface recombination velocity (SRV) of etched InP increased from 600 to similar to 4 x 10(4) cm/s after a 350 degrees C heat treatment and to about 4 x 10(5) cm/s following annealing at 500 degrees C. On the other hand annealings performed on Ar plasma treated samples increased the substrate's SRV to similar values following 80 and 200 degrees C heat treatments, respectively. Surface chemical analysis showed that the increase in SRV is associated with phosphorus loss from the crystal surface which creates recombination centers at the interface. The effect of these recombination centers on the open circuit voltage of ITO/InP solar cells is demonstrated and discussed. (C) 1997 American Vacuum Society. C1 NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401. RP Rosenwaks, Y (reprint author), TEL AVIV UNIV,DEPT PHYS EDUC,FAC ENGN,IL-69978 RAMAT AVIV,ISRAEL. NR 17 TC 1 Z9 1 U1 1 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 JUL-AUG PY 1997 VL 15 IS 4 BP 2354 EP 2358 DI 10.1116/1.580747 PG 5 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA XL335 UT WOS:A1997XL33500080 ER PT J AU Pai, WW Zhang, JD Wendelken, JF Warmack, RJ AF Pai, WW Zhang, JD Wendelken, JF Warmack, RJ TI Magnetic nanostructures fabricated by scanning tunneling microscope-assisted chemical vapor deposition SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article ID NANOMETER-SCALE MAGNETS; NANOFABRICATION; SURFACE; GROWTH AB We have successfully used scanning tunneling microscope-assisted chemical vapor deposition to fabricate magnetic nanostructures as fine as 5 nm wide and <2 nm high using ferrocene [Fe(C5H5)(2)] as the metal-organic source gas. The physical properties of these nanostructures were qualitatively characterized and ex situ magnetic force microscopy measurements indicate these features are strongly magnetic. C1 OAK RIDGE NATL LAB,HLTH SCI RES DIV,OAK RIDGE,TN 37831. RP Pai, WW (reprint author), OAK RIDGE NATL LAB,DIV SOLID STATE,POB 2008,OAK RIDGE,TN 37831, USA. NR 16 TC 31 Z9 31 U1 1 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 JUL-AUG PY 1997 VL 15 IS 4 BP 785 EP 787 DI 10.1116/1.589409 PG 3 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA XT088 UT WOS:A1997XT08800003 ER PT J AU Duxstad, KJ Haller, EE Yu, KM Bourret, ED Lin, XW Ruvimov, S LilientalWeber, Z Washburn, J AF Duxstad, KJ Haller, EE Yu, KM Bourret, ED Lin, XW Ruvimov, S LilientalWeber, Z Washburn, J TI Interfacial reaction behavior of Pt, Pd, and Ni on ZnSe SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article ID LASER-DIODES; GROWTH; PHASE; GAAS AB The solid-state reactions of Pt, Pd, and Ni thin film contacts on ZnSe were studied. Pd has been observed to react at 200 degrees C to form a ternary, epitaxial phase, Pds(5+x)ZnSe. This phase is stable up to 450 degrees C, when Pd begins to diffuse through the ZnSe into the GaAs substrate. Pt begins to react at 575 degrees C and forms a layer of Pt5Se4 at the Pt/ZnSe interface. Above the interfacial layer there is a Pt-Zn solid solution, but no Pt-Zn phases were observed. After annealing at 675 degrees C, the Pt5Se4 phase is no longer observed and Pt-Zn phases form. A small amount of interdiffusion at the Ni/ZnSe interface has been observed by transmission electron microscopy after annealing at 300 degrees C. Annealing at 425 degrees C results in the formation of laterally separated grains of a metastable NixSe phase. After annealing at 450 degrees C, grains of NiSe are observed. The similarities between these reactions and the near-noble metal reactions on Si and GaAs are discussed as well as the possibility of using these reactions for forming electrical contacts to ZnSe. (C) 1997 American Vacuum Society. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP Duxstad, KJ (reprint author), UNIV CALIF BERKELEY,DEPT MAT SCI & MINERAL ENGN,BERKELEY,CA 94720, USA. RI Liliental-Weber, Zuzanna/H-8006-2012; Yu, Kin Man/J-1399-2012 OI Yu, Kin Man/0000-0003-1350-9642 NR 22 TC 4 Z9 4 U1 0 U2 4 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 JUL-AUG PY 1997 VL 15 IS 4 BP 891 EP 898 DI 10.1116/1.589504 PG 8 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA XT088 UT WOS:A1997XT08800023 ER PT J AU Zhang, S Franke, JE Niemczyk, TM Haaland, DM Cox, JN Banerjee, I AF Zhang, S Franke, JE Niemczyk, TM Haaland, DM Cox, JN Banerjee, I TI Testing of a rapid fault detection model for quality control: Borophosphosilicate glass thin films monitored by infrared absorption spectroscopy SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article ID PHOSPHOSILICATE GLASS; QUANTITATIVE-ANALYSIS; PATTERN-RECOGNITION; SILICON-WAFERS; CALIBRATION; SPECTRA AB Infrared absorption spectra of 108 borophosphosilicate glass (BPSG) thin films produced in a multiple-wafer low-pressure chemical vapor deposition (LPCVD) reactor were collected to enable the development and testing of a rapid and inexpensive method for determining if films are within the desired specifications. Classification of samples into good and bad product categories was made by applying principal component analysis to the spectra. Mahalanobis distances were used as the classification metric. The highest overall percentage of correct classification of samples based upon their spectra with two-step classification was 95%. The misclassified samples were, however, within the error of the reference methods that were used in making the original classification against which the infrared (IR) classification methods were tested. The classification errors are thus just as likely to be a result of misclassification by the reference method rather than errors by the IR classification. Although reference measurements were used in this article for the original classification of the samples, these expensive and time-consuming reference methods can be eliminated simply by building classification models on samples determined to produce a product within the correct device specifications. The IR classification methods presented here hold great promise as a tool for rapid quality control of BPSG deposition. (C) 1997 American Vacuum Society. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. INTEL CORP,SANTA CLARA,CA 95052. RP Zhang, S (reprint author), UNIV NEW MEXICO,DEPT CHEM,ALBUQUERQUE,NM 87131, USA. NR 20 TC 9 Z9 10 U1 0 U2 0 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 JUL-AUG PY 1997 VL 15 IS 4 BP 955 EP 960 DI 10.1116/1.589514 PG 6 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA XT088 UT WOS:A1997XT08800033 ER PT J AU Ren, F Lee, JW Abernathy, CR Pearton, SJ Constantine, C Barratt, C Shul, RJ AF Ren, F Lee, JW Abernathy, CR Pearton, SJ Constantine, C Barratt, C Shul, RJ TI Dry etch damage in GaAs metal-semiconductor field-effect transistors exposed to inductively coupled plasma and electron cyclotron resonance Ar plasmas SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article AB The effects of Ar plasma exposure on transconductance, channel sheet resistance, output resistance, and gate contact ideality factor of GaAs metal-semiconductor field-effect transistors (MESFETs) were investigated using two different high-density plasma sources, namely inductively coupled plasma and electron resonance plasma. Ion-induced damage is found to be reduced at moderate source powers (similar to 200 W) because of the reduction in cathode dc self-bias and hence ion energy, but at higher source powers the increase in ion flux produces significant deterioration of the device performance. Careful attention must be paid to both ion flux and ion energy in order to minimize ion-induced damage. Due to their relatively low channel doping levels, MESFETs are found to be more sensitive to plasma damage than devices with very heavily doped component layers such as heterojunction bipolar transistors. (C) 1997 American Vacuum Society. C1 UNIV FLORIDA,DEPT MAT SCI & ENGN,GAINESVILLE,FL 32611. PLASMA THERM IP,ST PETERSBURG,FL 33716. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP Ren, F (reprint author), AT&T BELL LABS,LUCENT TECHNOL,MURRAY HILL,NJ 07974, USA. NR 29 TC 11 Z9 11 U1 1 U2 3 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 JUL-AUG PY 1997 VL 15 IS 4 BP 983 EP 989 DI 10.1116/1.589518 PG 7 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA XT088 UT WOS:A1997XT08800037 ER PT J AU Inglefield, CE DeLong, MC Taylor, PC Geisz, JF Olson, JM AF Inglefield, CE DeLong, MC Taylor, PC Geisz, JF Olson, JM TI Microwave modulated photoluminescence as a contactless probe of interface states SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article; Proceedings Paper CT 24th Annual Conference on the Physics and Chemistry of Semiconductor Interfaces (PCSI-24) CY JAN 12-15, 1997 CL RES TRIANGLE PK, NC ID III-V-SEMICONDUCTORS; EPITAXIAL GAAS AB Microwave modulated photoluminescence (MMPL) is a developing spectroscopy in which the sample is subjected to continuous optical pumping and chopped microwave electric fields. The signal detected in an MMPL experiment is the change in the photoluminescence spectrum of the sample due to the presence of microwave electric fields, which increase the kinetic energy of the free carriers. In order to investigate the effects of interfaces on this measured quantity, two types of GaAs samples have been compared. The first type of sample was grown such that the GaAs epilayers are exposed, while in the second type the GaAs is ''capped'' by a layer of higher band gap material. Several pairs of such samples have been studied. The MMPL results are consistent with the following mechanism: an increase in the kinetic energy of the free carriers that results from the presence of the microwave fields allows more free carriers to reach the interface or surface of the GaAs layer before recombining. The presence of a greater number of nonradiative recombination paths in the samples with a bare GaAs surface than at the GaAs/capping-layer interface is therefore seen experimentally as an increase in the photoluminescence quenching by the microwave electric fields. The potential usefulness of MMPL as a probe of non-radiative recombination and as an indicator of interface quality is illustrated by a quantitative estimate of surface/interface non-radiative recombination. (C) 1997 American Vacuum Society. C1 NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401. RP Inglefield, CE (reprint author), UNIV UTAH,DEPT PHYS,SALT LAKE CITY,UT 84112, USA. NR 14 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 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD JUL-AUG PY 1997 VL 15 IS 4 BP 1201 EP 1204 DI 10.1116/1.589439 PG 4 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA XT088 UT WOS:A1997XT08800075 ER PT J AU Tiller, BL Dagle, GE Cadwell, LL AF Tiller, BL Dagle, GE Cadwell, LL TI Testicular atrophy in a mule deer population SO JOURNAL OF WILDLIFE DISEASES LA English DT Article DE antler deformity; androgens; contaminants; mule deer; Odocoileus hemionus; testicular atrophy ID WHITE-TAILED DEER; XYLAZINE HYDROCHLORIDE; KETAMINE-HYDROCHLORIDE; IMMOBILIZATION AB Monitoring mule deer (Odocoileus hemionus) on a former plutonium production site along the Columbia River at the Hanford Site, Washington (USA) revealed 27 (23%) of 116 adult males had unusually shaped, velvet-covered antlers and abnormally developed testicles. We captured 32 males to examine age-class differences and the ratio of affected to unaffected deer and determine whether affected testicles were atrophic or hypoplastic. We found testicular atrophy in most deer with velvet-covered antlers, primarily in animals older than 5 yr. Deer had marked to extreme stages of testicular atrophy, indicating permanent sterility. Decreased serum levels of testosterone and compensatory increased levels of luteininzing hormone and follicle stimulating hormone were detected in all affected males; thus, the gondopituitary hormonal pathway may have responded to abnormally low levels of testosterone in the affected animals. Brucella spp. antibodies in sera were not detected and 9 (90%) of 10 affected animals were seropositive for epizootic hemorrhagic disease virus (EHDV-2) and bluetongue virus (BTV-11) as compared to 12 (63%) of 19 unaffected animals; however, signs of other infectious diseases were not observed. Testicular degeneration generally exceeded that observed with nutritional disorders and poisons in domestic species. Also, severity of the atrophy and apparent lack of other affected tissues suggested that radiation may not be responsible. Testicular atrophy in mule deer has been reported elsewhere; however, neither prevalence has been as high nor or occurrence as well confined to a specific geographical area, as that observed at the Hanford Site. Furthermore, no physiological or age-related influences were described. Documenting the status of such variables and examining their relationships to this phenomenon is a crucial step in understanding the reproductive capacity of a wild deer population. C1 WASHINGTON STATE UNIV, US URANIUM & TRANSURANIUM REGISTRY, RICHLAND, WA 99352 USA. RP Tiller, BL (reprint author), PACIFIC NW LAB, POB 999, RICHLAND, WA 99352 USA. RI WSU, USTUR/I-1056-2013 NR 52 TC 11 Z9 13 U1 0 U2 2 PU WILDLIFE DISEASE ASSN, INC PI LAWRENCE PA 810 EAST 10TH ST, LAWRENCE, KS 66044-8897 SN 0090-3558 J9 J WILDLIFE DIS JI J. Wildl. Dis. PD JUL PY 1997 VL 33 IS 3 BP 420 EP 429 PG 10 WC Veterinary Sciences SC Veterinary Sciences GA XM004 UT WOS:A1997XM00400004 PM 9249686 ER PT J AU Fitzsimmons, NN Buskirk, SW Smith, MH AF Fitzsimmons, NN Buskirk, SW Smith, MH TI Genetic changes in reintroduced Rocky Mountain bighorn sheep populations SO JOURNAL OF WILDLIFE MANAGEMENT LA English DT Article DE allelic variability; allozyme; bighorn sheep; conservation genetics; drift; genetic variability; Ovis canadensis; population genetics; reintroduction; Rocky Mountains; translocation; Wyoming ID CONSERVATION; DIVERSITY; SIZE; ELECTROPHORESIS; VARIABILITY; WILD AB We compared allozyme variability in 4 reintroduced populations of bighorn sheep (Ovis canadensis) with their common source population in Wyoming to understand how reintroduction affects genetic variability. Founder size was low (8-69) and effective population size (N-e) remained low 10-20 years after release. Allele frequencies at 2 of 4 polymorphic loci differed between the reintroduced herds and the common source (P < 0.01), and the number of alleles per locus was reduced in reintroduced herds (P = 0.04). Multi-locus heterozygosity (at 29 loci) was lower (P = 0.03) in 3 of the reintroduced herds than in the common source population. Simulations of genetic drift in reintroduced herds indicated that allele frequencies were within expectations of model predictions, but that heterozygosity sometimes varied from predictions. Our results indicate the operation of founder effect and subsequent genetic drift within the small reintroduced herds, but also may be influenced by small sample sizes from herds that were difficult to sample. We suggest management practices that should minimize the loss of genetic variation from reintroduced populations of bighorn sheep. C1 UNIV WYOMING, DEPT ZOOL & PHYSIOL, LARAMIE, WY 82071 USA. SAVANNAH RIVER ECOL LAB, AIKEN, SC 29801 USA. RI Buskirk, Steven/K-2871-2016 OI Buskirk, Steven/0000-0003-0611-6648 NR 48 TC 27 Z9 28 U1 3 U2 15 PU WILDLIFE SOC PI BETHESDA PA 5410 GROSVENOR LANE, BETHESDA, MD 20814-2197 SN 0022-541X J9 J WILDLIFE MANAGE JI J. Wildl. Manage. PD JUL PY 1997 VL 61 IS 3 BP 863 EP 872 DI 10.2307/3802195 PG 10 WC Ecology; Zoology SC Environmental Sciences & Ecology; Zoology GA XR474 UT WOS:A1997XR47400029 ER PT J AU Dadoo, R Yan, C Zare, RN Anex, DS Rakestraw, DJ Hux, GA AF Dadoo, R Yan, C Zare, RN Anex, DS Rakestraw, DJ Hux, GA TI Advances toward the routine use of capillary electrochromatography SO LC GC-MAGAZINE OF SEPARATION SCIENCE LA English DT Article ID PERFORMANCE LIQUID-CHROMATOGRAPHY; REVERSED-PHASE; PACKED CAPILLARIES; MASS-SPECTROMETRY; COLUMNS; ELECTROPHORESIS C1 UNIMICRO TECHNOL INC,PLEASANTON,CA 94566. SANDIA NATL LABS,LIVERMORE,CA 94551. RP Dadoo, R (reprint author), STANFORD UNIV,DEPT CHEM,STANFORD,CA 94305, USA. RI Zare, Richard/A-8410-2009 NR 35 TC 23 Z9 25 U1 1 U2 6 PU ADVANSTAR COMMUNICATIONS PI DULUTH PA 131 W FIRST ST, DULUTH, MN 55802 SN 0888-9090 J9 LC GC-MAG SEP SCI JI LC GC-Mag. Sep. Sci. PD JUL PY 1997 VL 15 IS 7 BP 630 EP & PG 5 WC Chemistry, Analytical SC Chemistry GA XK066 UT WOS:A1997XK06600006 ER PT J AU Burton, H AF Burton, H TI ''Almost a man of genius'': Clemence Royer, feminism, and nineteenth-century science - Harvey,J SO LIBRARY JOURNAL LA English DT Book Review RP Burton, H (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU BOWKER MAGAZINE GROUP CAHNERS MAGAZINE DIVISION PI NEW YORK PA 249 W 17TH ST, NEW YORK, NY 10011 SN 0363-0277 J9 LIBR J JI Libr. J. PD JUL PY 1997 VL 122 IS 12 BP 118 EP 118 PG 1 WC Information Science & Library Science SC Information Science & Library Science GA XK069 UT WOS:A1997XK06900301 ER PT J AU Brzezinski, MA Phillips, DR AF Brzezinski, MA Phillips, DR TI Evaluation of Si-32 as a tracer for measuring silica production rates in marine waters SO LIMNOLOGY AND OCEANOGRAPHY LA English DT Article ID BIOGENIC SILICA; SARGASSO SEA; ACID UPTAKE; CYCLE; PHYTOPLANKTON; OCEAN AB The radioisotope Si-32 was evaluated as a tracer for measuring silica production rates in marine waters. Si-32 is a weak beta-emitter that decays to P-32 allowing the isotope to be used to determine simultaneously the production rate of biogenic silica and organic phosphorus. High specific activity Si-32, 42,000-52,000 Bq (mu g Si)(-1), was produced by the proton spallation of KCl. Reasonable tracer additions result in only nanomolar increases in the ambient silicic acid and orthophosphate concentrations during production rate experiments. Protocols for quantifying the amount of Si-32 and P-32 in samples by liquid scintillation counting (LSC) and gas-flow proportional counting (GFPC) are presented. Both protocols eliminate the 4-month wait for secular equilibrium between Si-32 and P-32 required by earlier methods. GFPC is especially useful as the instrumentation is lightweight and portable allowing real-time analysis of samples at sea. Real-time analysis by GFPC at sea and postcruise analysis by LSC gave results that agreed to within 17 and 7% for Si-32 and P-32, respectively. Subsequent intercalibrations of the LSC and GFPC methods indicated that agreement to within 0.1-4% for both isotopes can be achieved. Parallel incubations of samples from Monterey Bay, California, using the radioisotope Si-32 and the stable isotope Si-30 gave silica production rates that generally agreed to within 30%. No significant bias was observed between rates obtained with the two tracers. The greater sensitivity and ease of analysis of the radioisotope makes Si-32 the tracer of choice for future studies of silica production in the ocean. C1 LOS ALAMOS NATL LAB,RADIOISOTOPE PROGRAM,CST 11,LOS ALAMOS,NM 87545. RP Brzezinski, MA (reprint author), UNIV CALIF SANTA BARBARA,DEPT ECOL EVOLUT & MARINE BIOL,SANTA BARBARA,CA 93106, USA. NR 23 TC 60 Z9 60 U1 0 U2 8 PU AMER SOC LIMNOLOGY OCEANOGRAPHY PI WACO PA 5400 BOSQUE BLVD, STE 680, WACO, TX 76710-4446 SN 0024-3590 J9 LIMNOL OCEANOGR JI Limnol. Oceanogr. PD JUL PY 1997 VL 42 IS 5 BP 856 EP 865 PG 10 WC Limnology; Oceanography SC Marine & Freshwater Biology; Oceanography GA YK661 UT WOS:A1997YK66100006 ER PT J AU Schrum, DP Alugupalli, S Kelly, ST White, DC Fayer, R AF Schrum, DP Alugupalli, S Kelly, ST White, DC Fayer, R TI Structural characterization of a ''signature'' phosphatidylethanolamine as the major 10-hydroxy stearic acid-containing lipid of Cryptosporidium parvum oocysts SO LIPIDS LA English DT Article ID BOMBARDMENT MASS-SPECTROMETRY; FATTY-ACID; PHOSPHOLIPIDS AB A 10-hydroxy stearic acid-containing lipid from Cryptosporidium parvum was purified by thin-layer chromatography and analyzed by infrared spectroscopy, fast-atom bombardment mass spectrometry, H-1 and P-31 nuclear magnetic resonance spectroscopy, and was identified as phosphatidylethanolamine. C1 UNIV TENNESSEE,CTR ENVIRONM BIOTECHNOL,KNOXVILLE,TN 37932. OAK RIDGE NATL LAB,DIV ENVIRONM SCI,OAK RIDGE,TN 37831. USDA ARS,BELTSVILLE AGR RES CTR,LPSI,PARASITE IMMUNOL LAB,BELTSVILLE,MD 20705. RP Schrum, DP (reprint author), MICROBIAL INSIGHTS INC,2340 STOCK CREEK BLVD,ROCKFORD,TN 37853, USA. NR 15 TC 4 Z9 4 U1 0 U2 3 PU AMER OIL CHEMISTS SOC PI CHAMPAIGN PA 1608 BROADMOOR DRIVE, CHAMPAIGN, IL 61821-0489 SN 0024-4201 J9 LIPIDS JI Lipids PD JUL PY 1997 VL 32 IS 7 BP 789 EP 793 DI 10.1007/s11745-997-0102-4 PG 5 WC Biochemistry & Molecular Biology; Nutrition & Dietetics SC Biochemistry & Molecular Biology; Nutrition & Dietetics GA XM427 UT WOS:A1997XM42700015 PM 9252970 ER PT J AU Alam, TM Assink, RA AF Alam, TM Assink, RA TI Solid-state C-13 CP/MAS NMR investigations of EDTA-metal complexes SO MAGNETIC RESONANCE IN CHEMISTRY LA English DT Article DE C-13 CP/MAS NMR; EDTA; carboxyl CSA tensor ID ACID; ION AB Solid-state C-13 CP/MAS NMR spectra are reported for different EDTA-metal complexes. The effect of metal binding on the isotropic C-13 chemical shift and principal elements of the carboxyl C-13 chemical shift anisotropy (CSA) tensor are discussed. (C) 1997 by John Wiley & Sons, Ltd. RP Alam, TM (reprint author), SANDIA NATL LABS,BULK PROPERTIES DEPT,MS 1407,ALBUQUERQUE,NM 87185, USA. NR 13 TC 7 Z9 7 U1 0 U2 2 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0749-1581 J9 MAGN RESON CHEM JI Magn. Reson. Chem. PD JUL PY 1997 VL 35 IS 7 BP 427 EP 431 DI 10.1002/(SICI)1097-458X(199707)35:7<427::AID-OMR101>3.0.CO;2-J PG 5 WC Chemistry, Multidisciplinary; Chemistry, Physical; Spectroscopy SC Chemistry; Spectroscopy GA XJ763 UT WOS:A1997XJ76300001 ER PT J AU Neuhaus, IM Sommardahl, CS Johnson, DK Beier, DR AF Neuhaus, IM Sommardahl, CS Johnson, DK Beier, DR TI Microsatellite DNA variants between the FVB/N and C3HeB/FeJLe and C57BL/6J mouse strains SO MAMMALIAN GENOME LA English DT Article C1 HARVARD UNIV,BRIGHAM & WOMENS HOSP,SCH MED,DIV GENET,BOSTON,MA 02115. OAK RIDGE NATL LAB,DIV BIOL,OAK RIDGE,TN 37831. FU NIDDK NIH HHS [DK45639] NR 4 TC 10 Z9 10 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0938-8990 J9 MAMM GENOME JI Mamm. Genome PD JUL PY 1997 VL 8 IS 7 BP 506 EP 509 DI 10.1007/s003359900485 PG 4 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity GA XG180 UT WOS:A1997XG18000010 PM 9195996 ER PT J AU Timms, SJ Lynn, NM Mount, ME Sivintsev, Y Warden, JM AF Timms, SJ Lynn, NM Mount, ME Sivintsev, Y Warden, JM TI Modelling the release to the Kara Sea of radioactive waste from the icebreaker Lenin: Version II SO MARINE POLLUTION BULLETIN LA English DT Article AB In progressing its work for the International Arctic Seas Assessment Project (IASAP), under the auspices of the International Atomic Energy Agency (IAEA), the Source Term Working Group has developed a FORTRAN model to predict a radiation release profile into the Kara Sea from reactor fuel and activated components of the nuclear icebreaker Lenin. The model accounts for the degradation of containment materials through corrosion and other mechanisms, and predicts annual release rates to 4500 years into the future. Version I of the model was developed as a spreadsheet program from the original data gathered by the Working Group and the results were published by Timms ef al. (1994); revised information on the method of disposal necessitated a change to the program, which is presented in this paper as Version II. The model is being applied to other marine reactors dumped in the Kara Sea in a programme of work for the IASAP aimed at assessing the collective release profile from all significant dump sites in this region. (C) 1997 Published by Elsevier Science Ltd. All rights reserved. C1 Royal Naval Coll Greenwich, Dept Nucl Sci & Technol, London SE10 9NN, England. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Russia Res Ctr, Kurchatov Inst, Moscow 123182, Russia. RP Royal Naval Coll Greenwich, Dept Nucl Sci & Technol, London SE10 9NN, England. NR 14 TC 1 Z9 1 U1 0 U2 0 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 JUL-DEC PY 1997 VL 35 IS 7-12 BP 365 EP 373 DI 10.1016/S0025-326X(97)00153-7 PG 9 WC Environmental Sciences; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA 101PK UT WOS:000074877200020 ER PT J AU Templeton, WL AF Templeton, WL TI Research needed relative to radiological assessment of the dumping of radioactive wastes in the oceans SO MARINE POLLUTION BULLETIN LA English DT Article AB The purpose of this paper is twofold. First, the paper provides a historical review of international activities regarding radiation in the sea. Secondly, the paper provides some recommendations for future research needed for realistic dose assessment of the present and potential impact of ocean disposal and dumping operations. (C) 1997 Published by Elsevier Science Ltd. All rights reserved. C1 Pacific NW Lab, Off Hlth & Environm, Richland, WA 99352 USA. RP Pacific NW Lab, Off Hlth & Environm, Richland, WA 99352 USA. NR 17 TC 0 Z9 1 U1 0 U2 0 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 JUL-DEC PY 1997 VL 35 IS 7-12 BP 374 EP 380 DI 10.1016/S0025-326X(97)00154-9 PG 7 WC Environmental Sciences; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA 101PK UT WOS:000074877200021 ER PT J AU Buttrey, DJ Vogt, T Yap, GPA Rheingold, AL AF Buttrey, DJ Vogt, T Yap, GPA Rheingold, AL TI The structure of Bi26Mo10O69 SO MATERIALS RESEARCH BULLETIN LA English DT Article DE oxides; X-ray diffraction; neutron scattering; crystal structure ID CRYSTAL-STRUCTURE AB The structure of Bi26Mo10O69 was solved using a combination of X-ray and neutron diffraction. The final refinement was completed using high resolution neutron powder diffraction in a monoclinic cell [a = 1.17456(3) nm, b = 0.57988(1) nm, c = 2.47919(5) nm, beta = 102.903(1)degrees, P2/c], neglecting a very subtle triclinic distortion resolved only with synchrotron X-ray data. This phase exhibits a solid solubility range of approximately 2.6 less than or equal to Bi/Mo less than or equal to 2.8, with the ideal ratio at 2.6 and one of the Bi sites disordered. The structure is rationalized by comparison with other bismuth molybdates using valence bond sums and Madelung site potentials. As with several other bismuth molybdates, there is significant charge transfer between Bi-rich channels and surrounding molybdenum tetrahedra in this fluorite-related structure. (C) 1997 Elsevier Science Ltd. C1 BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. UNIV DELAWARE,DEPT CHEM & BIOCHEM,NEWARK,DE 19716. RP Buttrey, DJ (reprint author), UNIV DELAWARE,CTR CATALYT SCI & TECHNOL,DEPT CHEM ENGN,NEWARK,DE 19716, USA. RI Vogt, Thomas /A-1562-2011 OI Vogt, Thomas /0000-0002-4731-2787 NR 23 TC 33 Z9 33 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0025-5408 J9 MATER RES BULL JI Mater. Res. Bull. PD JUL PY 1997 VL 32 IS 7 BP 947 EP 963 DI 10.1016/S0025-5408(97)00063-9 PG 17 WC Materials Science, Multidisciplinary SC Materials Science GA XE056 UT WOS:A1997XE05600018 ER PT J AU Rawers, J Krabbe, R Duttlinger, N AF Rawers, J Krabbe, R Duttlinger, N TI Nanostructure characterization of mechanical alloyed and consolidated iron alloys SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE nanostructured material; iron alloys; stress ID NANOCRYSTALLINE AB High-energy ball milling (which is readily adoptable to commercial application) was used to develop sufficient quantities of nanostructured material to produce compacts capable of being measured for macroscopic properties. Characterization of the ball-milled powders show that grain boundary properties play a significant role in the overall properties of the milled powder. Nearly full-dense compacts were produced by hot-pressing. Characterization of the strength properties of these compacts show that there was little influence of hardness, density, or alloy composition on the failure properties. The range of failure stress was large and when fitted to a Weibull distribution suggest that failure was the result of flaws or cracks resulting from the hot-pressing. Hardness data, commonly used to evaluate the strength of nanostructured materials: showed no correlation to tensile strength, but correlated highly to compression maximum stress. (C) 1997 Elsevier Science S.A. RP Rawers, J (reprint author), US DOE,ALBANY RES CTR,1450 QUEEN AVE SW,ALBANY,OR 97321, USA. NR 15 TC 18 Z9 18 U1 0 U2 2 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD JUL 1 PY 1997 VL 230 IS 1-2 BP 139 EP 145 DI 10.1016/S0921-5093(97)00015-4 PG 7 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA XM776 UT WOS:A1997XM77600019 ER PT J AU Wright, JK Williamson, RL Cannon, RM AF Wright, JK Williamson, RL Cannon, RM TI Finite element analysis of the effects of corners on residual stresses in protective oxide scales SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE finite element analysis; protective oxide scales; residual stress ID METAL; INTERFACE; CRACKING; GROWTH; MECHANICS; JOINTS; ALLOYS; FILMS AB Finite element simulations are used to examine residual thermal stresses and strains in corner regions of protective Al2O3 scales on Fe3Al specimens, both during cooling from oxide formation temperatures and during subsequent thermal cycling. The effects of a corner's radius of curvature and oxide thickness, as well as the impact of aluminide plasticity, are considered. Localized plasticity is found to have a major influence on net deformation and on the magnitude and location of maximum stress. As the ratio of corner curvature to oxide thickness (r(s)/f) is reduced, stresses within the oxide corner shift from highly compressive to tensile and the location of the maximum principal stress moves from the substrate to the oxide scale. Based on these stress distributions prior to the development of any flaws, key implications about the tendencies for damage are addressed. The stress evolution during cooling and thermal cycling is presented; these results demonstrate the effects of temperature-dependent material properties. For the material behavior assumed in this study, thermal cycling does not cause significant stress relaxation. (C) 1997 Elsevier Science S.A. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP Wright, JK (reprint author), IDAHO NATL ENGN & ENVIRONM LAB,POB 1625,IDAHO FALLS,ID 83415, USA. OI Wright, Jill/0000-0001-8909-8144 NR 22 TC 9 Z9 10 U1 0 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD JUL 1 PY 1997 VL 230 IS 1-2 BP 202 EP 212 DI 10.1016/S0921-5093(97)00032-4 PG 11 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA XM776 UT WOS:A1997XM77600027 ER PT J AU Grossenbacher, K Karasaki, K Bahat, D AF Grossenbacher, K Karasaki, K Bahat, D TI Curved scanline theory SO MATHEMATICAL GEOLOGY LA English DT Article DE interval; scan line; fracture; statistics ID ROCK; RQD AB This work develops the theory of measuring fracture frequency with curved scanlines, as a direct development of work done by others on straight scanlines. Various possible shapes for curved scanlines range between triangular and rectangular, with circular as a reasonable preliminary selection. The discrepancy among different selections decreases with increasing roughness amplitude of the scanline. Analytic solutions for average fracture frequency are given for circular scanlines through single and multiple fracture sets. Results for single fracture sets are plotted. The analytic solution for the general situation of any shape scanline through multiple fracture sets is given. Analytic solutions are given and plotted for circular scanlines through a fracture fabric ellipsoid. A circular scanline spanning 180 degrees yields a global fracture frequency of statistical significance. C1 BEN GURION UNIV NEGEV,DEPT GEOL & MINERAL,IL-84105 BEER SHEVA,ISRAEL. RP Grossenbacher, K (reprint author), LAWRENCE BERKELEY LAB,DIV EARTH SCI,1 CYCLOTRON RD,BERKELEY,CA 94720, USA. NR 19 TC 1 Z9 1 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0882-8121 J9 MATH GEOL JI Math. Geol. PD JUL PY 1997 VL 29 IS 5 BP 629 EP 651 DI 10.1007/BF02769648 PG 23 WC Geosciences, Multidisciplinary; Mathematics, Interdisciplinary Applications SC Geology; Mathematics GA XL477 UT WOS:A1997XL47700002 ER PT J AU Davis, GJ Morris, MD AF Davis, GJ Morris, MD TI Six factors which affect the condition number of matrices associated with kriging SO MATHEMATICAL GEOLOGY LA English DT Article DE stability; conditioning; robustness ID COVARIANCE AB Determining kriging weights to estimate some variable of interest at a given point in the field involves solving a system of linear equations. The matrix of this linear system is subject to numerical instability, and this instability is measured by the matrix condition number. Six parameters in the kriging process have been identified which directly affect this condition number. Analysis of a series of 648 experiments gives some insight on these parameters, and how the condition number relates to kriging variance. C1 OAK RIDGE NATL LAB,CSM DIV,MATH SCI SECT,OAK RIDGE,TN 37830. RP Davis, GJ (reprint author), GEORGIA STATE UNIV,ATLANTA,GA 30303, USA. NR 12 TC 18 Z9 18 U1 0 U2 3 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0882-8121 J9 MATH GEOL JI Math. Geol. PD JUL PY 1997 VL 29 IS 5 BP 669 EP 683 DI 10.1007/BF02769650 PG 15 WC Geosciences, Multidisciplinary; Mathematics, Interdisciplinary Applications SC Geology; Mathematics GA XL477 UT WOS:A1997XL47700004 ER PT J AU Cockburn, B Jones, DA Titi, ES AF Cockburn, B Jones, DA Titi, ES TI Estimating the number of asymptotic degrees of freedom for nonlinear dissipative systems SO MATHEMATICS OF COMPUTATION LA English DT Article ID NAVIER-STOKES EQUATIONS; INERTIAL MANIFOLDS; DETERMINING NODES; VOLUME ELEMENTS; ATTRACTORS; DIMENSION; TIME; APPROXIMATIONS; CRITERION AB We show that the long-time behavior of the projection of the exact solutions to the Navier-Stokes equations and other dissipative evolution equations on the finite-dimensional space of interpolant polynomials determines the long-time behavior of the solution itself provided that the spatial mesh is fine enough. We also provide an explicit estimate on the size of the mesh. Moreover, we show that if the evolution equation has an inertial manifold, then the dynamics of the evolution equation is equivalent to the dynamics of the projection of the solutions on the finite-dimensional space spanned by the approximating polynomials. Our results suggest that certain numerical schemes may capture the essential dynamics of the underlying evolution equation. C1 LOS ALAMOS NATL LAB,IGPP,LOS ALAMOS,NM 87544. UNIV CALIF IRVINE,DEPT MATH,IRVINE,CA 92697. UNIV CALIF IRVINE,DEPT MECH & AEROSP ENGN,IRVINE,CA 92697. RP Cockburn, B (reprint author), UNIV MINNESOTA,SCH MATH,MINNEAPOLIS,MN 55455, USA. RI Cockburn, Bernardo/M-9617-2013 OI Cockburn, Bernardo/0000-0001-6085-3441 NR 35 TC 38 Z9 39 U1 0 U2 3 PU AMER MATHEMATICAL SOC PI PROVIDENCE PA 201 CHARLES ST, PROVIDENCE, RI 02940-2213 SN 0025-5718 J9 MATH COMPUT JI Math. Comput. PD JUL PY 1997 VL 66 IS 219 BP 1073 EP 1087 DI 10.1090/S0025-5718-97-00850-8 PG 15 WC Mathematics, Applied SC Mathematics GA XT788 UT WOS:A1997XT78800008 ER PT J AU Kahan, W Li, RC AF Kahan, W Li, RC TI Composition constants for raising the orders of unconventional schemes for ordinary differential equations SO MATHEMATICS OF COMPUTATION LA English DT Article DE ordinary differential equations; reflexive methods; composition schemes; palindromic schemes ID SYMPLECTIC INTEGRATORS; GENERAL-THEORY AB Many models of physical and chemical processes give rise to ordinary differential equations with special structural properties that go unexploited by general-purpose software designed to solve numerically a wide range of differential equations. If those properties are to be exploited fully for the sake of better numerical stability, accuracy and/or speed, the differential equations may have to be served by unconventional methods. This short paper is to publish composition constants obtained by the authors to increase efficiency of a family of mostly unconventional methods, called reflective. C1 UNIV CALIF BERKELEY,DEPT MATH,BERKELEY,CA 94720. OAK RIDGE NATL LAB,MATH SCI SECT,OAK RIDGE,TN 37831. RP Kahan, W (reprint author), UNIV CALIF BERKELEY,DIV COMP SCI,BERKELEY,CA 94720, USA. NR 13 TC 40 Z9 40 U1 0 U2 2 PU AMER MATHEMATICAL SOC PI PROVIDENCE PA 201 CHARLES ST, PROVIDENCE, RI 02940-2213 SN 0025-5718 J9 MATH COMPUT JI Math. Comput. PD JUL PY 1997 VL 66 IS 219 BP 1089 EP 1099 DI 10.1090/S0025-5718-97-00873-9 PG 11 WC Mathematics, Applied SC Mathematics GA XT788 UT WOS:A1997XT78800009 ER PT J AU Hoyt, PR Bartholomew, C Davis, AJ Yutzey, K Gamer, LW Potter, SS Ihle, JN Mucenski, ML AF Hoyt, PR Bartholomew, C Davis, AJ Yutzey, K Gamer, LW Potter, SS Ihle, JN Mucenski, ML TI The Evil proto-oncogene is required at midgestation for neural, heart, and paraxial mesenchyme development SO MECHANISMS OF DEVELOPMENT LA English DT Article DE Evil; homologous recombination; cell proliferation; mouse; embryogenesis ID MYELOID-TRANSFORMING GENE; RECEPTOR TYROSINE KINASE; ZINC FINGER GENE; TARGETED DISRUPTION; MICE LACKING; EMBRYONIC LETHALITY; MOUSE DEVELOPMENT; CELL-LINE; EXPRESSION; SEQUENCE AB The ecotropic viral integration site-1 (Evi1) locus was initially identified as a common site of retroviral integration in myeloid tumors of the AKXD-23 recombinant inbred mouse strain. The full-length Evi1 transcript encodes a putative transcription factor, containing ten zinc finger motifs found within two domains of the protein. To determine the biological function of the Evi1 proto-oncogene, the full-length, but not an alternately spliced, transcript was disrupted using targeted mutagenesis in embryonic stem cells. Evi1 homozygous mutant embryos die at approximately 10.5 days post coitum. Mutants were distinguished at 10.5 days post coitum by widespread hypocellularity, hemorrhaging, and disruption in the development of paraxial mesenchyme. In addition, defects in the heart, somites, and cranial ganglia were detected and the peripheral nervous system failed to develop, These results correlated with whole-mount in situ hybridization analyses of embryos which showed expression of the Evi1 proto-oncogene in embryonic mesoderm and neural crest-derived cells associated with the peripheral nervous system. These data suggest that Evi1 has important roles in general cell proliferation, vascularization, and cell-specific developmental signaling, at midgestation. (C) 1997 Elsevier Science Ireland Ltd. C1 UNIV TENNESSEE, OAK RIDGE NATL LAB, SCH BIOMED SCI, DIV BIOL, OAK RIDGE, TN 37831 USA. ST JUDE CHILDRENS RES HOSP, DEPT BIOCHEM, MEMPHIS, TN 38105 USA. PENN STATE UNIV, DEPT BIOL, STATE COLL, PA 16802 USA. CHILDRENS HOSP RES FDN, DIV BASIC SCI RES, CINCINNATI, OH 45229 USA. VANDERBILT UNIV, DEPT CELL BIOL, NASHVILLE, TN 37232 USA. FU NICHD NIH HHS [N01-HD-62915] NR 62 TC 100 Z9 103 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0925-4773 J9 MECH DEVELOP JI Mech. Dev. PD JUL PY 1997 VL 65 IS 1-2 BP 55 EP 70 DI 10.1016/S0925-4773(97)00057-9 PG 16 WC Developmental Biology SC Developmental Biology GA XM198 UT WOS:A1997XM19800005 PM 9256345 ER PT J AU Thakur, AM Thadhani, NN Schwarz, RB AF Thakur, AM Thadhani, NN Schwarz, RB TI Shock-induced martensitic transformations in near-equiatomic NiTi alloys SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article ID TENSILE-STRESS PULSE; INDUCED NUCLEATION; C ALLOY AB Shock-impact generated tensile-stress pulses were used to induce B2-to-monoclinic martensitic transformations in two near-equiatomic NiTi alloys having different martensite transformation start (M-3) temperatures. The NiTi-I alloy (M-s approximate to + 27 degrees C) impacted at room temperature at 2.0 and 2.7 GPa tensile stress-pulse magnitude, showed acicular martensite morphology. These martensite needles had a substructure containing microtwins, typical of ''stress-assisted'' martensite. The NiTi-II alloy (M-s approximate to -45 degrees C) showed no martensite formation when shocked with tensile-stress pulses of 2 GPa. For tensile stresses of 4.1 GPa, the alloy showed spall initiation near the region of maximum tensile-stress duration. In addition, monoclinic martensite needles, with a well-defined dislocation substructure, typical of ''strain-induced'' martensite, were seen clustering around the spall region. No stress-assisted martensite was formed in this alloy due to its very low M-s temperature. The present article documents results of the use of a metallurgical technique for generating large-amplitude tensile stress pulses of finite duration for studies of phase transformations involving changes from a high density to a low density state. C1 GEORGIA INST TECHNOL, SCH MAT SCI & ENGN, ATLANTA, GA 30332 USA. LOS ALAMOS NATL LAB, CTR MAT SCI, LOS ALAMOS, NM 87565 USA. RP UNIV CINCINNATI, DEPT MAT SCI & ENGN, CINCINNATI, OH 45221 USA. NR 26 TC 12 Z9 14 U1 1 U2 10 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1073-5623 EI 1543-1940 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD JUL PY 1997 VL 28 IS 7 BP 1445 EP 1455 DI 10.1007/s11661-997-0207-2 PG 11 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA XL481 UT WOS:A1997XL48100005 ER PT J AU ZeislerMashl, KL Lograsso, TA AF ZeislerMashl, KL Lograsso, TA TI The occurrence and periodicity of oscillating peritectic microstructures developed during directional solidification SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article AB The layered microstructures that can form during plane-front directional solidification in peritectic systems were characterized quantitatively as a function of growth velocity using a Sn-Cd alloy. Layers were formed for an alloy composition outside of the two-phase peritectic region in the absence of longitudinal macrosegregation. The layers did not extend over the entire sample cross sections, so that the layered regions had a different composition than the alloy. Each of the two solids was found to be interconnected and continuous in three dimensions. The layer lengths and individual layer compositions did not vary with solidification distance. The average layer compositions were not a function of growth velocity and were approximately those at the peritectic temperature. This research was compared to the current model by Trivedi, which is based upon cyclic accumulation and depletion of solute in the liquid ahead of the interface linked to repeated nucleation events. The dependence of layer length on growth velocity predicted by the model was not obtained experimentally. The differences between results and predictions are related to the continuity of the two solids and the nonuniform cross-sectional composition in the Sn-Cd samples, which contradict assumptions of the model. A formation mechanism involving competitive lateral growth between the two solids at the solid-liquid interface would be more consistent with the current research. C1 IOWA STATE UNIV,USDA,AMES LAB,AMES,IA 50011. RP ZeislerMashl, KL (reprint author), USN,RES LAB,PHYS MET BRANCH,WASHINGTON,DC 20375, USA. NR 17 TC 10 Z9 11 U1 0 U2 1 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 JUL PY 1997 VL 28 IS 7 BP 1543 EP 1552 DI 10.1007/s11661-997-0216-1 PG 10 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA XL481 UT WOS:A1997XL48100014 ER PT J AU Caffee, MW Nishiizumi, K AF Caffee, MW Nishiizumi, K TI Exposure ages of carbonaceous chondrites .2. SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract C1 LAWRENCE LIVERMORE NATL LAB,GEOSCI & ENVIRONM TECHNOL DIV,LIVERMORE,CA 94551. UNIV CALIF BERKELEY,SPACE SCI LAB,BERKELEY,CA 94720. NR 5 TC 7 Z9 7 U1 0 U2 0 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD JUL PY 1997 VL 32 IS 4 SU S BP A26 EP A26 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA XP024 UT WOS:A1997XP02400043 ER PT J AU Gibson, EK Romanek, CS McKay, DS ThomasKeprta, K Allen, CC Wentworth, S AF Gibson, EK Romanek, CS McKay, DS ThomasKeprta, K Allen, CC Wentworth, S TI Nature of carbon phases in Allan Hills 84001. SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract ID MARTIAN METEORITE ALH84001; MARS C1 NASA,LYNDON B JOHNSON SPACE CTR,PLANETARY SCI BRANCH,HOUSTON,TX 77058. UNIV GEORGIA,SAVANNAH RIVER ECOL LAB,AIKEN,SC 29802. NASA,LYNDON B JOHNSON SPACE CTR,LOCKHEED MARTIN,HOUSTON,TX 77058. NR 10 TC 0 Z9 0 U1 0 U2 0 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD JUL PY 1997 VL 32 IS 4 SU S BP A47 EP A47 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA XP024 UT WOS:A1997XP02400084 ER PT J AU Herzog, GF Aggrey, K Metzler, K Hildebrand, AR Bouchard, M Jull, AJT Andrews, HR Wang, MS Ferko, T Lipschutz, ME Wacker, JF Wieler, R AF Herzog, GF Aggrey, K Metzler, K Hildebrand, AR Bouchard, M Jull, AJT Andrews, HR Wang, MS Ferko, T Lipschutz, ME Wacker, JF Wieler, R TI Preatmospheric size of the St-Robert (H5) chondrite. SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract ID PRODUCTION-RATES; DEPTH C1 RUTGERS STATE UNIV, DEPT CHEM, NEW BRUNSWICK, NJ 08903 USA. RAMAPO COLL, SCH THEORET & APPL SCI, MAHWAH, NJ 07430 USA. INST PLANETOL, D-48149 MUNSTER, GERMANY. GEOL SURVEY CANADA, OTTAWA, ON K1A 0Y3, CANADA. UNIV MONTREAL, DEPT GEOL, MONTREAL, PQ H3C 3J7, CANADA. UNIV ARIZONA, NSF, ACCELATOR FACIL RADIOISOTOPE ANAL, TUCSON, AZ 85721 USA. AECL RES, CHALK RIVER LABS, CHALK RIVER, ON K0J 1J0, CANADA. PURDUE UNIV, DEPT CHEM, W LAFAYETTE, IN 47907 USA. PACIFIC NW LAB, RICHLAND, WA 99352 USA. ETH ZURICH, NO C61, CH-8092 ZURICH, SWITZERLAND. RI Wieler, Rainer/A-1355-2010 OI Wieler, Rainer/0000-0001-5666-7494 NR 10 TC 2 Z9 2 U1 0 U2 0 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD JUL PY 1997 VL 32 IS 4 SU S BP A59 EP A59 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA XP024 UT WOS:A1997XP02400108 ER PT J AU Hills, JG Goda, MP AF Hills, JG Goda, MP TI The largest mass of nickel-iron meteorites. SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM. NR 1 TC 0 Z9 0 U1 0 U2 0 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD JUL PY 1997 VL 32 IS 4 SU S BP A60 EP A60 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA XP024 UT WOS:A1997XP02400111 ER PT J AU Hutcheon, ID Phinney, DL Hutchison, R AF Hutcheon, ID Phinney, DL Hutchison, R TI Radiogenic chromium-53 in CI carbonates: New evidence of early aqueous activity. SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract C1 LAWRENCE LIVERMORE NATL LAB,ISOTOPE SCI DIV,LIVERMORE,CA 94551. NAT HIST MUSEUM,DEPT MINERAL,LONDON SW7 5BD,ENGLAND. NR 4 TC 5 Z9 5 U1 0 U2 0 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD JUL PY 1997 VL 32 IS 4 SU S BP A63 EP A64 PG 2 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA XP024 UT WOS:A1997XP02400117 ER PT J AU Marti, K Lavielle, B Jeannot, JP Mathew, KJ Palma, RL Nishiizumi, K Caffee, MW AF Marti, K Lavielle, B Jeannot, JP Mathew, KJ Palma, RL Nishiizumi, K Caffee, MW TI Search for genetic links in irons of groups IIE and IVA. SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract ID METEORITES C1 UNIV CALIF SAN DIEGO,DEPT CHEM,LA JOLLA,CA 92093. CEN BORDEAUX GRADIGNAN,URA 451 CNRS,F-33175 GRADIGNAN,FRANCE. SAM HOUSTON STATE UNIV,DEPT PHYS,HUNTSVILLE,TX 77341. UNIV CALIF BERKELEY,SPACE SCI LAB,BERKELEY,CA 94720. LAWRENCE LIVERMORE NATL LAB,INST GEOPHYS & PLANETARY PHYS,LIVERMORE,CA 94550. NR 8 TC 0 Z9 0 U1 0 U2 0 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD JUL PY 1997 VL 32 IS 4 SU S BP A84 EP A85 PG 2 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA XP024 UT WOS:A1997XP02400159 ER PT J AU Nicolussi, GK Davis, AM Pellin, MJ Lewis, RS Clayton, RN Amari, S AF Nicolussi, GK Davis, AM Pellin, MJ Lewis, RS Clayton, RN Amari, S TI The s-process in asymptotic giant branch (AGB) stars: Clues from zirconium and molybdenum isotopic compositions of individual presolar silicon carbide grains. SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract C1 UNIV CHICAGO,ENRICO FERMI INST,CHICAGO,IL 60637. UNIV CHICAGO,DEPT GEOPHYS SCI,CHICAGO,IL 60637. UNIV CHICAGO,DEPT CHEM,CHICAGO,IL 60637. ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. WASHINGTON UNIV,MCDONNELL CTR SPACE SCI,ST LOUIS,MO 63130. RI Pellin, Michael/B-5897-2008 OI Pellin, Michael/0000-0002-8149-9768 NR 4 TC 0 Z9 0 U1 0 U2 0 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD JUL PY 1997 VL 32 IS 4 SU S BP A99 EP A99 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA XP024 UT WOS:A1997XP02400188 ER PT J AU Nishiizumi, K Caffee, MW Jeannot, JP Lavielle, B Honda, M AF Nishiizumi, K Caffee, MW Jeannot, JP Lavielle, B Honda, M TI A systematic study of the cosmic-ray-exposure history of iron meteorites: Beryllium-10-chlorine-36/beryllium-10 terrestrial ages. SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract C1 UNIV CALIF BERKELEY,SPACE SCI LAB,BERKELEY,CA 94720. LAWRENCE LIVERMORE NATL LAB,GEOSCI & ENVIRONM TECHNOL DIV,LIVERMORE,CA 94551. UNIV BORDEAUX 1,CEN BORDEAUX GRADIGNAN,URA 451 CNRS,F-33175 GRADIGNAN,FRANCE. NIHON UNIV,DEPT CHEM,TOKYO,JAPAN. NR 2 TC 12 Z9 12 U1 0 U2 0 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD JUL PY 1997 VL 32 IS 4 SU S BP A100 EP A100 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA XP024 UT WOS:A1997XP02400189 ER PT J AU ThomasKeprta, KL Wentworth, SJ McKay, DS Taunton, AE Allen, CC Romanek, CS Gibson, EK AF ThomasKeprta, KL Wentworth, SJ McKay, DS Taunton, AE Allen, CC Romanek, CS Gibson, EK TI Subsurface terrestrial microfossils from Columbia river basalt samples: Analogs of features in Martian meteorite Allan Hills 84001? SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract ID CARBONATE C1 NASA,LYNDON B JOHNSON SPACE CTR,LOCKHEED MARTIN,HOUSTON,TX 77058. UNIV ARKANSAS,DEPT CHEM & BIOCHEM,FAYETTEVILLE,AR 72701. UNIV GEORGIA,SAVANNAH RIVER ECOL LAB,AIKEN,SC 29802. NR 5 TC 2 Z9 2 U1 0 U2 2 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD JUL PY 1997 VL 32 IS 4 SU S BP A128 EP A129 PG 2 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA XP024 UT WOS:A1997XP02400245 ER PT J AU Wacker, JF AF Wacker, JF TI Cosmogenic aluminum-26 and other radionuclides in meteorites. SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract ID NUCLIDES C1 PACIFIC NW LAB, RICHLAND, WA 99352 USA. NR 7 TC 1 Z9 1 U1 0 U2 0 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD JUL PY 1997 VL 32 IS 4 SU S BP A133 EP A134 PG 2 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA XP024 UT WOS:A1997XP02400255 ER PT J AU Wolf, SF Lipschutz, ME AF Wolf, SF Lipschutz, ME TI Volatile-trace-element content and petrographic type in equilibrated H chondrites. SO METEORITICS & PLANETARY SCIENCE LA English DT Meeting Abstract ID PARENT BODIES; METEORITES C1 ARGONNE NATL LAB, ARGONNE, IL 60439 USA. PURDUE UNIV, DEPT CHEM, W LAFAYETTE, IN 47907 USA. NR 10 TC 0 Z9 0 U1 0 U2 0 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 1086-9379 EI 1945-5100 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD JUL PY 1997 VL 32 IS 4 SU S BP A141 EP A142 PG 2 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA XP024 UT WOS:A1997XP02400270 ER PT J AU Pierce, DG Brusius, PG AF Pierce, DG Brusius, PG TI Electromigration: A review SO MICROELECTRONICS RELIABILITY LA English DT Review ID THIN-FILM CONDUCTORS; INTEGRATED-CIRCUITS; CURRENT-DENSITY; INDUCED FAILURE; ALUMINUM; AL; DEPENDENCE; STRESS; LINES; RELIABILITY AB The aggressive scaling planned for integrated circuits is placing more demands on the materials, processes and designs. The circuits must be reliable and electromigration is a key reliability issue. Because many of the factors that contribute to electromigration are not completely understood, manufacturers must proceed cautiously. In this article electromigration is reviewed from the prospective of the reliability engineer, focusing on those areas of greatest applicability to the manufacturing environment. First, the fundamental physics of electromigration are examined to provide a basis for understanding the factors that affect the lifetimes under the various test conditions. Then, empirical data concerning the impact on reliability of metal stripe geometry, structure and composition are reviewed. The care necessary to make fast, wafer-level tests an important process control tool is discussed. It is shown that pulsed-de and ac waveforms can provide longer lifetimes than predicted previously, providing some relaxation of current density requirements for higher circuit densities. An understanding of these phenomena is necessary for the reliability engineer to assess today's and tomorrow's integrated circuits. (C) 1997 Elsevier Science Ltd. C1 HONEYWELL SSEC, PLYMOUTH, MN 55441 USA. SANDIA NATL LABS, ALBUQUERQUE, NM 87185 USA. NR 126 TC 124 Z9 128 U1 8 U2 40 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0026-2714 J9 MICROELECTRON RELIAB JI Microelectron. Reliab. PD JUL PY 1997 VL 37 IS 7 BP 1053 EP 1072 DI 10.1016/S0026-2714(96)00268-5 PG 20 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA WY851 UT WOS:A1997WY85100009 ER PT J AU Thundat, T Oden, PI Warmack, RJ AF Thundat, T Oden, PI Warmack, RJ TI Microcantilever sensors SO MICROSCALE THERMOPHYSICAL ENGINEERING LA English DT Review ID FORCE MICROSCOPE CANTILEVERS; RESONATING MICROCANTILEVERS; MICROMECHANICAL SENSORS; STRESS AB The advent of inexpensive, mass-produced microcantilevers promises to bring about a revolution in the field of chemical, physical, and biological sensor development. The microcantilever resonance responses such as resonance frequency, deflection, amplitude, and Q-factor undergo variation due to external stimuli. The resonance response variation can be due to mass loading, surface stress, or damping. When molecules adsorb on surfaces they can also produce a surface stress due to forces involved in the adsorption process and can be observed as changes in deflections of a thin microcantilever, In this article we review the technology and present a series of highly sensitive sensors that are based on commercially available microcantilevers used in atomic force microscopy. RP Thundat, T (reprint author), OAK RIDGE NATL LAB,HLTH SCI RES DIV,MS-6123,OAK RIDGE,TN 37831, USA. NR 30 TC 162 Z9 164 U1 1 U2 30 PU TAYLOR & FRANCIS PI BRISTOL PA 1900 FROST ROAD, SUITE 101, BRISTOL, PA 19007-1598 SN 1089-3954 J9 MICROSCALE THERM ENG JI Microscale Thermophys. Eng. PD JUL-SEP PY 1997 VL 1 IS 3 BP 185 EP 199 PG 15 WC Thermodynamics; Engineering, Mechanical; Nanoscience & Nanotechnology; Materials Science, Characterization & Testing; Physics, Applied SC Thermodynamics; Engineering; Science & Technology - Other Topics; Materials Science; Physics GA XX594 UT WOS:A1997XX59400003 ER PT J AU Campbell, GH Cohen, D King, WE AF Campbell, GH Cohen, D King, WE TI Data preparation for quantitative high-resolution electron microscopy SO MICROSCOPY AND MICROANALYSIS LA English DT Article DE transmission electron microscopy; high resolution electron microscopy; quantitative high resolution electron microscopy; image processing ID IMAGES AB A method is described to prepare a high-resolution electron micrograph for quantitative comparison with a simulated high-resolution image. The experimental data are converted from the darkening of film used to acquire the image to units of electrons per incident electron, the same units used in the simulation. Also, distortions in the image arising from distortions in the image-forming lenses of the electron microscope are removed to improve the quality of the data. Finally, an alignment procedure is described which gives precise, pixel-by-pixel alignment of the experimental image with the simulated image. Examples of the procedure are shown to illustrate how actual data are prepared for quantitative analysis. RP Campbell, GH (reprint author), LAWRENCE LIVERMORE NATL LAB,CHEM & MAT SCI DIRECTORATE,MAIL STOP L-356,POB 808,LIVERMORE,CA 94551, USA. RI Campbell, Geoffrey/F-7681-2010 NR 11 TC 6 Z9 6 U1 0 U2 1 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 1431-9276 J9 MICROSC MICROANAL JI Microsc. microanal. PD JUL-AUG PY 1997 VL 3 IS 4 BP 299 EP 310 PG 12 WC Materials Science, Multidisciplinary; Microscopy SC Materials Science; Microscopy GA XK953 UT WOS:A1997XK95300001 ER PT J AU Benedek, R Seidman, DN Yang, LH AF Benedek, R Seidman, DN Yang, LH TI Atomistic simulation of ceramic/metal interfaces: {222}MgO/Cu SO MICROSCOPY AND MICROANALYSIS LA English DT Article; Proceedings Paper CT 1997 Arizona-State-University (ASU) Electron Microscopy Workshop on Atomic Structure and Chemistry of Boundaries/Interfaces CY JAN 08-11, 1997 CL ARIZONA STATE UNIV, TEMPE, AZ SP Arizona State Univ (ASU), Arizona State Univ, Ctr Solid State Sci, Facil High Resolut Microscopy HO ARIZONA STATE UNIV DE interface; simulation; molecular dynamics; dislocation; interatomic potential; electronic structure ID MISFIT DISLOCATIONS; METAL AB Atomistic simulations were performed for the {222}MgO/Cu interface by local density functional theory (LDFT) methods, within the plane-wave-pseudopotential representation, and by (classical) molecular dynamics and statics. The electronic spectra obtained with LDFT calculations showed a localized interface state within the bulk MgO gap, approximately 1 eV above the MgO valence band edge. LDFT adhesive energy calculations, as a function of interface spacing and translations parallel to the interface, were employed to devise an interatomic potential suitable for large-scale atomistic simulation. The interface structure, which was obtained with molecular dynamics (and statics) calculations based on the resultant potential, exhibited a misfit dislocation network with trigonal symmetry, and no standoff dislocations. C1 NORTHWESTERN UNIV, DEPT MAT SCI & ENGN, EVANSTON, IL 60208 USA. NORTHWESTERN UNIV, MAT RES CTR, EVANSTON, IL 60208 USA. LAWRENCE LIVERMORE NATL LAB, CONDENSED MATTER PHYS DIV, LIVERMORE, CA 94551 USA. RI Seidman, David/B-6697-2009 NR 17 TC 19 Z9 19 U1 0 U2 2 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 32 AVENUE OF THE AMERICAS, NEW YORK, NY 10013-2473 USA SN 1431-9276 J9 MICROSC MICROANAL JI Microsc. microanal. PD JUL-AUG PY 1997 VL 3 IS 4 BP 333 EP 338 PG 6 WC Materials Science, Multidisciplinary; Microscopy SC Materials Science; Microscopy GA XK953 UT WOS:A1997XK95300005 ER PT J AU Merkle, KL AF Merkle, KL TI Atomic-scale grain boundary relaxation modes in metals and ceramics SO MICROSCOPY AND MICROANALYSIS LA English DT Article; Proceedings Paper CT 1997 Arizona-State-University (ASU) Electron Microscopy Workshop on Atomic Structure and Chemistry of Boundaries/Interfaces CY JAN 08-11, 1997 CL ARIZONA STATE UNIV, TEMPE, AZ SP Arizona State Univ (ASU), Arizona State Univ, Ctr Solid State Sci, Facil High Resolut Microscopy HO ARIZONA STATE UNIV DE high-resolution electron microscopy; grain boundaries; excess volume; 3-fold astigmatism; oxides; metals; constraints ID TRANSMISSION ELECTRON-MICROSCOPY; COMPUTER-SIMULATION; 3-FOLD ASTIGMATISM; HREM; DISSOCIATION; SIGMA-9; ENERGY; NIO AB The atomic-scale structure of tilt grain boundaries has been studied by high-resolution electron microscopy (HREM) in several ceramics and metals such as NiO, yttria stabilized zirconia, Au, and Al. It is found that when grain boundaries are formed between two crystals a considerable variety of modes of relaxations, i.e., the rearrangements of atoms in and near the grain boundary core are possible, depending on grain boundary geometry and the interatomic interactions. Tile atomic relaxations within and near the grain boundary core often include relaxations that involve the formation of stacking faults in low-stacking-fault energy fee materials. Grain boundary dissociations are also observed for several grain boundary geometries. Computer simulations of grain boundary structures in metals have in general been able to reproduce the relaxation features at least on a qualitative level. In contrast, ceramic grain boundaries typically are more complex and not always tractable by simple computer relaxation procedures, since the formation of point defects and partial occupancy of atomic columns may be involved in the relaxation processes. It is found that when a boundary is not allowed to relax to its lowest energy state due to geometrical constraints, a multitude of grain boundary core structures can exist. Such conditions are expected to be characteristic for nanocrystalline materials. Because of its close connection to grain boundary properties, quantification of the volume expansion by HREM techniques is an important goal of grain boundary research. Image simulations of grain boundaries suggest that for most materials of interest the 3-fold astigmatism must be corrected to better than 100 nm to achieve the desired accuracies. RP Merkle, KL (reprint author), ARGONNE NATL LAB,DIV MAT SCI,BLDG 212,ARGONNE,IL 60439, USA. NR 38 TC 14 Z9 15 U1 1 U2 7 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 1431-9276 J9 MICROSC MICROANAL JI Microsc. microanal. PD JUL-AUG PY 1997 VL 3 IS 4 BP 339 EP 351 PG 13 WC Materials Science, Multidisciplinary; Microscopy SC Materials Science; Microscopy GA XK953 UT WOS:A1997XK95300006 ER PT J AU Karimi, M Stapay, G Kaplan, T Mostoller, M AF Karimi, M Stapay, G Kaplan, T Mostoller, M TI Temperature dependence of the elastic constants of Ni: reliability of EAM in predicting thermal properties SO MODELLING AND SIMULATION IN MATERIALS SCIENCE AND ENGINEERING LA English DT Article ID METALS; SIMULATIONS AB The temperature dependence of the elastic constants of Ni is calculated using molecular dynamics (MD) simulations in conjunction with the embedded atom method (EAM). The Parrinello-Rahman version of molecular dynamics is employed along with the fluctuation formulae in the H sigma N and EhN ensembles at various temperatures from 0 K to somewhat below the melting point (experimental value 1725 K). The calculated results for the elastic constants, compressibility, linear coefficient of thermal expansion, specific heat and the melting temperature compare reasonably well to experiment. C1 OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. RP Karimi, M (reprint author), INDIANA UNIV PENN,DEPT PHYS,INDIANA,PA 15705, USA. NR 21 TC 23 Z9 24 U1 1 U2 5 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL, ENGLAND BS1 6BE SN 0965-0393 J9 MODEL SIMUL MATER SC JI Model. Simul. Mater. Sci. Eng. PD JUL PY 1997 VL 5 IS 4 BP 337 EP 346 DI 10.1088/0965-0393/5/4/003 PG 10 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA XW773 UT WOS:A1997XW77300003 ER PT J AU Buchheit, TE Bourcier, RJ Wellman, GW Neilsen, MK AF Buchheit, TE Bourcier, RJ Wellman, GW Neilsen, MK TI Capturing the influence of surface constraints in small and thin samples using polycrystalline plasticity theory SO MODELLING AND SIMULATION IN MATERIALS SCIENCE AND ENGINEERING LA English DT Article ID DUCTILE SINGLE-CRYSTALS; CRYSTALLOGRAPHIC TEXTURE; RATE SENSITIVITY; FCC METALS; DEFORMATION; STRAIN; FORMULATION; EVOLUTION; MODELS AB A rate-dependent, single-crystal plasticity model for face-centred cubic crystal structures has been implemented into a large strain elastic-plastic, finite-element code to examine the mechanical influence of the reduced surface constraints of relatively small polycrystalline aggregates. The implemented model simulates deformation of a polycrystal composed of cubic grains where each grain is a single finite element. Mechanical constraint is varied by changing (a) specimen thickness and (b) specimen volume, relative to grain size. Numerical uniaxial tensile tests have been performed to a strain level of 0.01. Direct and statistical examination of the model results revealed the reduced flow stress of grains at specimen surfaces, edges and corners. The results of these simulations are in good agreement with previous experimental studies which suggest that 5-10 grains across the minimum dimension of a structure are necessary to approximate true continuum polycrystalline response. C1 SANDIA NATL LABS, DEPT MECH & MFG ENGN, ALBUQUERQUE, NM 87185 USA. RP Buchheit, TE (reprint author), SANDIA NATL LABS, THEORET & COMPUTAT MAT MODELLING DEPT, POB 5800, ALBUQUERQUE, NM 87185 USA. RI bourcier, romain/D-6896-2015 OI bourcier, romain/0000-0002-6506-4019 NR 38 TC 8 Z9 8 U1 0 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL, ENGLAND BS1 6BE SN 0965-0393 J9 MODEL SIMUL MATER SC JI Model. Simul. Mater. Sci. Eng. PD JUL PY 1997 VL 5 IS 4 BP 421 EP 437 DI 10.1088/0965-0393/5/4/009 PG 17 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA XW773 UT WOS:A1997XW77300009 ER PT J AU Jervis, T AF Jervis, T TI ''Packaging'' lessons should include energy and recycling issues SO MRS BULLETIN LA English DT Letter RP Jervis, T (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87544, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 SN 0883-7694 J9 MRS BULL JI MRS Bull. PD JUL PY 1997 VL 22 IS 7 BP 4 EP 4 PG 1 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA XK168 UT WOS:A1997XK16800002 ER PT J AU Li, LH Krantz, ID Deng, Y Genin, A Banta, AB Collins, CC Qi, M Trask, BJ Kuo, WL Cochran, J Costa, T Pierpont, MEM Rand, EB Piccoli, DA Hood, L Spinner, NB AF Li, LH Krantz, ID Deng, Y Genin, A Banta, AB Collins, CC Qi, M Trask, BJ Kuo, WL Cochran, J Costa, T Pierpont, MEM Rand, EB Piccoli, DA Hood, L Spinner, NB TI Alagille syndrome is caused by mutations in human Jagged1, which encodes a ligand for Notch1 SO NATURE GENETICS LA English DT Article ID INTERLOBULAR BILE-DUCTS; DROSOPHILA-NOTCH; CELL-FATE; ARTERIOHEPATIC DYSPLASIA; PHYSICAL MAP; HOMOLOG; EXPRESSION; GENE; DELETION; PAUCITY AB Alagille syndrome is an autosomal dominant disorder characterized by abnormal development of liver, heart, skeleton, eye, face and, less frequently, kidney. Analyses of many patients with cytogenetic deletions or rearrangements have mapped the gene to chromosome 20p12, although deletions are found in a relatively small proportion of patients (< 7%). We have mapped the human Jagged1 gene (JAG1), encoding a ligand for the developmentally important Notch transmembrane receptor, to the Alagille syndrome critical region within 20p12. The Notch intercellular signalling pathway has been shown to mediate cell fate decisions during development in invertebrates and vertebrates. We demonstrate four distinct coding mutations in JAG1 from four Alagille syndrome families, providing evidence that it is the causal gene for Alagille syndrome. All four mutations lie within conserved regions of the gene and cause translational frameshifts, resulting in gross alterations of the protein product. Patients with cytogenetically detectable deletions including JAG1 have Alagille syndrome, supporting the hypothesis that haploinsufficiency for this gene is one of the mechanisms causing the Alagille syndrome phenotype. C1 UNIV PENN,CHILDRENS HOSP,SCH MED,DIV HUMAN GENET,PHILADELPHIA,PA 19104. UNIV PENN,CHILDRENS HOSP,SCH MED,DIV GASTROENTEROL & NUTR,PHILADELPHIA,PA 19104. UNIV WASHINGTON,STOWERS INST MED RES,SEATTLE,WA 98195. UNIV WASHINGTON,DEPT MOL BIOTECHNOL,SEATTLE,WA 98195. FUDAN UNIV,INST GENET,SHANGHAI 200433,PEOPLES R CHINA. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV LIFE SCI,BERKELEY,CA 94720. UNIV WASHINGTON,DEPT MED,DIV MED GENET,SEATTLE,WA 98195. UNIV WASHINGTON,DEPT PATHOL,SEATTLE,WA 98195. UNIV CALIF SAN FRANCISCO,CTR CANC,CANC GENET PROGRAM,SAN FRANCISCO,CA 94141. HOSP SICK CHILDREN,DEPT GENET,TORONTO,ON M5G 1X8,CANADA. UNIV MINNESOTA,DEPT PEDIAT,MINNEAPOLIS,MN 55455. UNIV MINNESOTA,INST HUMAN GENET,MINNEAPOLIS,MN 55455. FU NICHD NIH HHS [5 P30 HD288215]; NIDDK NIH HHS [1R01DK53104-01, DK02338-03] NR 54 TC 674 Z9 695 U1 1 U2 12 PU NATURE PUBLISHING CO PI NEW YORK PA 345 PARK AVE SOUTH, NEW YORK, NY 10010-1707 SN 1061-4036 J9 NAT GENET JI Nature Genet. PD JUL PY 1997 VL 16 IS 3 BP 243 EP 251 DI 10.1038/ng0797-243 PG 9 WC Genetics & Heredity SC Genetics & Heredity GA XG609 UT WOS:A1997XG60900018 PM 9207788 ER PT J AU Tinoco, I Kieft, JS AF Tinoco, I Kieft, JS TI The ion core in RNA folding SO NATURE STRUCTURAL BIOLOGY LA English DT Article ID HAMMERHEAD RIBOZYME; HAIRPINS; HELIX; CLEAVAGE; INTRONS; LOOPS; MODEL AB Metal ions that link phosphates and guanine bases are necessary for the folding of an RNA enzyme. A magnesium ion cove may be a common feature of RNA structure. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,STRUCT BIOL DIV,BERKELEY,CA 94720. RP Tinoco, I (reprint author), UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720, USA. NR 32 TC 22 Z9 22 U1 0 U2 0 PU NATURE PUBLISHING CO PI NEW YORK PA 345 PARK AVE SOUTH, NEW YORK, NY 10010-1707 SN 1072-8368 J9 NAT STRUCT BIOL JI Nat. Struct. Biol. PD JUL PY 1997 VL 4 IS 7 BP 509 EP 512 DI 10.1038/nsb0797-509 PG 4 WC Biochemistry & Molecular Biology; Biophysics; Cell Biology SC Biochemistry & Molecular Biology; Biophysics; Cell Biology GA XH735 UT WOS:A1997XH73500002 PM 9228937 ER PT J AU Wang, ZM Luecke, H Yao, NH Quiocho, FA AF Wang, ZM Luecke, H Yao, NH Quiocho, FA TI A low energy short hydrogen bond in very high resolution structures of protein receptor phosphate complexes SO NATURE STRUCTURAL BIOLOGY LA English DT Letter ID SPECIFICITY AB A very short hydrogen bond between an Asp and a phosphate is established in two high resolution structures (0.98 and 1.05 Angstrom). A mutant complex that changes the Asp to an Asn,which forms a normal hydrogen bond, has a similar free energy of binding to the wild type complex, suggesting that the contribution of the short hydrogen bond is not extraordinarily strong. C1 BAYLOR COLL MED,STRUCT & COMPUTAT BIOL & MOL BIOPHYS PROGRAM,HOUSTON,TX 77030. BAYLOR COLL MED,HOWARD HUGHES MED INST,HOUSTON,TX 77030. BAYLOR COLL MED,DEPT BIOCHEM,HOUSTON,TX 77030. STANFORD SYNCHROTRON RADIAT LAB,STANFORD,CA 94305. RI Luecke, Hartmut "Hudel"/F-4712-2012 OI Luecke, Hartmut "Hudel"/0000-0002-4938-0775 NR 26 TC 73 Z9 74 U1 0 U2 8 PU NATURE PUBLISHING CO PI NEW YORK PA 345 PARK AVE SOUTH, NEW YORK, NY 10010-1707 SN 1072-8368 J9 NAT STRUCT BIOL JI Nat. Struct. Biol. PD JUL PY 1997 VL 4 IS 7 BP 519 EP 522 DI 10.1038/nsb0797-519 PG 4 WC Biochemistry & Molecular Biology; Biophysics; Cell Biology SC Biochemistry & Molecular Biology; Biophysics; Cell Biology GA XH735 UT WOS:A1997XH73500007 PM 9228942 ER PT J AU Goodwill, KE Sabatier, C Marks, C Raag, R Fitzpatrick, PF Stevens, RC AF Goodwill, KE Sabatier, C Marks, C Raag, R Fitzpatrick, PF Stevens, RC TI Crystal structure of tyrosine hydroxylase at 2.3 angstrom and its implications for inherited neurodegenerative diseases SO NATURE STRUCTURAL BIOLOGY LA English DT Article ID ELECTRON-DENSITY MAPS; PHENYLALANINE-HYDROXYLASE; PROTEIN STRUCTURES; POINT MUTATION; PROGRAM; GENE; IDENTIFICATION; MECHANISM; DATABASE; FAMILIES AB Tyrosine hydroxylase (TyrOH) catalyzes the conversion of tyrosine to L-DOPA, the rate-limiting step in the biosynthesis of the catecholamines dopamine, adrenaline, and noradrenaline, TyrOH is highly homologous in terms of both protein sequence and catalytic mechanism to phenylalanine hydroxylase (PheOH)and tryptophan hydroxylase (TrpOH). The crystal structure of the catalytic and tetramerization domains of TyrOH reveals a novel alpha-helical basket holding the catalytic iron and a 40 Angstrom long anti-parallel coiled coil which forms the core of the tetramer, The catalytic iron is located 10 Angstrom below the enzyme surface in a 17 Angstrom deep active site pocket and is coordinated by the conserved residues His 331, His 336 and Glu 376. The structure provides a rationale for the effect of point mutations in TyrOH that cause L-DOPA responsive parkinsonism and Segawa's syndrome. The location of 112 different point mutations in PheOH that lead to phenylketonuria (PKU) are predicted based on the TyrOH structure. C1 UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. UNIV CALIF BERKELEY,EARNEST ORLANDO LAWRENCE BERKELEY NATL LAB,BERKELEY,CA 94720. TEXAS A&M UNIV,DEPT BIOCHEM & BIOPHYS,COLLEGE STN,TX 77843. NR 44 TC 231 Z9 233 U1 3 U2 22 PU NATURE PUBLISHING CO PI NEW YORK PA 345 PARK AVE SOUTH, NEW YORK, NY 10010-1707 SN 1072-8368 J9 NAT STRUCT BIOL JI Nat. Struct. Biol. PD JUL PY 1997 VL 4 IS 7 BP 578 EP 585 DI 10.1038/nsb0797-578 PG 8 WC Biochemistry & Molecular Biology; Biophysics; Cell Biology SC Biochemistry & Molecular Biology; Biophysics; Cell Biology GA XH735 UT WOS:A1997XH73500016 PM 9228951 ER PT J AU Fowler, JS Volkow, ND Wang, GJ Logan, J Pappas, N Shea, C Macgregor, R AF Fowler, JS Volkow, ND Wang, GJ Logan, J Pappas, N Shea, C Macgregor, R TI Age-related increases in brain monoamine oxidase B in living healthy human subjects SO NEUROBIOLOGY OF AGING LA English DT Article DE human brain MAO B; aging; positron emission tomography (PET) ID POSITRON EMISSION TOMOGRAPHY; ALZHEIMERS-DISEASE; FRONTAL-CORTEX; DEMENTIA; BINDING; INHIBITION; PLASMA; PET AB Several studies of human brain postmortem report that monoamine oxidase B (MAO B) increases with age and it has been proposed that this increase reflects age-associated increases in glial cells. We measured brain MAO B in a group of normal healthy human subjects (n = 21; age range 23-86; 9 females and 12 males; nonsmokers) using [C-11]L-deprenyl-D2 and positron emission tomography. Brain glucose metabolism was also measured with (18)FDG in 15 of the subjects. MAO B increased (p < 0.004) in all brain regions examined except the cingulate gyrus. In contrast, subjects showed the expected regional age-related decreases in blood flow and metabolism. In the 15 subjects in whom both MAO B and LCMRglu was measured, there was a trend (p < 0.03) toward an inverse association between brain glucose metabolism and MAO B activity in the frontal and parietal cortices. Although the age-related increase in brain MAO B in living subjects is consistent with postmortem reports, the degree of increase is generally lower. (C) 1997 Elsevier Science Inc. C1 BROOKHAVEN NATL LAB, DEPT MED, UPTON, NY 11973 USA. SUNY STONY BROOK, DEPT PSYCHIAT, STONY BROOK, NY 11974 USA. RP Fowler, JS (reprint author), BROOKHAVEN NATL LAB, DEPT CHEM, UPTON, NY 11973 USA. FU NINDS NIH HHS [NS 15380] NR 34 TC 114 Z9 118 U1 0 U2 3 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0197-4580 J9 NEUROBIOL AGING JI Neurobiol. Aging PD JUL-AUG PY 1997 VL 18 IS 4 BP 431 EP 435 DI 10.1016/S0197-4580(97)00037-7 PG 5 WC Geriatrics & Gerontology; Neurosciences SC Geriatrics & Gerontology; Neurosciences & Neurology GA XZ921 UT WOS:A1997XZ92100017 PM 9330975 ER PT J AU Eberling, JL Roberts, JA Rapp, PR Tuszynski, MH Jagust, WJ AF Eberling, JL Roberts, JA Rapp, PR Tuszynski, MH Jagust, WJ TI Cerebral glucose metabolism and memory in aged rhesus macaques SO NEUROBIOLOGY OF AGING LA English DT Article DE PET; aging; rhesus macaques; glucose metabolism; hippocampus; orbitofrontal cortex; delayed response; memory; monkey ID MEDIAL THALAMIC LESIONS; PREFRONTAL CORTEX; SENILE PLAQUES; MACACA-MULATTA; COGNITIVE DECLINE; NONHUMAN-PRIMATES; SYNAPTIC DENSITY; REGIONAL CHANGES; WORKING-MEMORY; MONKEY BRAIN AB Positron emission tomography and the glucose metabolic tracer [F-18]fluorodeoxyglucose were used to evaluate the relationship between regional cerebral metabolic rates for glucose (rCMRglc), age, and performance on a delayed response (DR) test of memory in the aged monkey. Eleven aged animals, 21-26-years old, were included in the analysis. Regional CMRglc, normalized to values for the entire brain, were determined for the dorsal prefrontal cortex, orbitofrontal cortex, hippocampus, and temporal cortex. The aged animals exhibited significant DR deficits relative to a cohort of normal young monkeys. Variability in DR performance among the aged subjects was significantly correlated with relative hippocampal rCMRglc, and chronological age was a reliable predictor of orbitofrontal rCMRglc ratios. This pattern of results suggests that DR impairments in the aged monkey may partly reflect ape-related dysfunction distributed among multiple limbic system structures that participate in normal learning and memory. Overall, the findings support the use of positron emission tomography in efforts to define the relationship between cognitive performance, age, and brain physiology in nonhuman primates. (C) 1997 Elsevier Science Inc. C1 UNIV CALIF,CALIF REG PRIMATE RES CTR,DAVIS,CA 95616. SUNY STONY BROOK,CTR BEHAV NEUROSCI,STONY BROOK,NY 11794. UNIV CALIF SAN DIEGO,DEPT NEUROSCI,LA JOLLA,CA 92093. UNIV CALIF DAVIS,DEPT NEUROL,DAVIS,CA 95616. RP Eberling, JL (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,CTR FUNCT IMAGING,1 CYCLOTON RD,BERKELEY,CA 94720, USA. FU NCRR NIH HHS [RR00169]; NIA NIH HHS [AG07793, AG10606] NR 53 TC 24 Z9 24 U1 0 U2 0 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 0197-4580 J9 NEUROBIOL AGING JI Neurobiol. Aging PD JUL-AUG PY 1997 VL 18 IS 4 BP 437 EP 443 DI 10.1016/S0197-4580(97)00040-7 PG 7 WC Geriatrics & Gerontology; Neurosciences SC Geriatrics & Gerontology; Neurosciences & Neurology GA XZ921 UT WOS:A1997XZ92100018 PM 9330976 ER PT J AU Pennell, WE Malik, SNM AF Pennell, WE Malik, SNM TI Structural integrity assessment of aging nuclear reactor pressure vessels SO NUCLEAR ENGINEERING AND DESIGN LA English DT Article AB Irradiation embrittlement reduces both the cleavage fracture toughness and the ductile tearing toughness of reactor pressure vessel (RPV) steels. Extensive research programs have investigated the fracture behavior of heavy-section vessels containing flaws. Information obtained from that research has been used to develop regulatory guidance for evaluating the structural integrity of irradiated RPVs. Additional research programs have developed fracture analysis methods, and generated the data required for their implementation. Regulatory guidance employs fracture analysis technology to assure that adequate fracture-prevention margins for RPVs are maintained throughout the licensed operating period of nuclear power plants. (C) 1997 Published by Elsevier Science S.A. C1 US NUCL REGULATORY COMMISS,OFF NUCL REGULATORY RES,DIV ENGN TECHNOL,WASHINGTON,DC. RP Pennell, WE (reprint author), OAK RIDGE NATL LAB,ENGN TECHNOL DIV,POB 2009,OAK RIDGE,TN 37831, USA. NR 51 TC 3 Z9 8 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0029-5493 J9 NUCL ENG DES JI Nucl. Eng. Des. PD JUL PY 1997 VL 172 IS 1-2 BP 27 EP 47 DI 10.1016/S0029-5493(96)00006-4 PG 21 WC Nuclear Science & Technology SC Nuclear Science & Technology GA XV843 UT WOS:A1997XV84300004 ER PT J AU Darrow, DS Zweben, SJ Chang, Z Cheng, CZ Diesso, MD Fredrickson, ED Mazzucato, E Nazikian, R Phillips, CK Popovichev, S Redi, MH White, RB Wilson, JR Wong, KL AF Darrow, DS Zweben, SJ Chang, Z Cheng, CZ Diesso, MD Fredrickson, ED Mazzucato, E Nazikian, R Phillips, CK Popovichev, S Redi, MH White, RB Wilson, JR Wong, KL TI Observations neutral beam and ICRF tail ion losses due to Alfven modes in TFTR SO NUCLEAR FUSION LA English DT Article ID CHARGED FUSION PRODUCTS; TOROIDAL FIELD RIPPLE; ENERGETIC PARTICLES; TEST REACTOR; TAE MODES; DIII-D; EIGENMODES; INSTABILITIES; TOKAMAKS; CONFINEMENT AB Experimental observations from TFTR of fast ion losses resulting from the toroidicity induced Alfven eigenmode (TAE) and the Alfven frequency mode (AFM) are presented. The AFM was driven by neutral beam ions, at low B-T, and the TAE was excited by hydrogen minority ion cyclotron range of frequencies (ICRF) tail ions at higher B-T. The measurements indicate that the loss rate varies linearly with the mode amplitude for both modes, and that the fast ion losses during the mode activity can be significant, with tens of per cent of the input power lost in the worst cases. C1 IV KURCHATOV ATOM ENERGY INST, RUSSIAN RES CTR, MOSCOW 123182, RUSSIA. RP Darrow, DS (reprint author), PRINCETON UNIV, PRINCETON PLASMA PHYS LAB, POB 451, PRINCETON, NJ 08543 USA. RI White, Roscoe/D-1773-2013; Cheng, Chio/K-1005-2014 OI White, Roscoe/0000-0002-4239-2685; NR 46 TC 31 Z9 31 U1 0 U2 4 PU INT ATOMIC ENERGY AGENCY PI VIENNA PA WAGRAMERSTRASSE 5, PO BOX 100, A-1400 VIENNA, AUSTRIA SN 0029-5515 J9 NUCL FUSION JI Nucl. Fusion PD JUL PY 1997 VL 37 IS 7 BP 939 EP 954 DI 10.1088/0029-5515/37/7/I03 PG 16 WC Physics, Fluids & Plasmas SC Physics GA XT873 UT WOS:A1997XT87300003 ER PT J AU Hooper, EB AF Hooper, EB TI Plasma based neutron sources SO NUCLEAR FUSION LA English DT Editorial Material RP Hooper, EB (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 1 TC 2 Z9 2 U1 0 U2 0 PU INT ATOMIC ENERGY AGENCY PI VIENNA PA WAGRAMERSTRASSE 5, PO BOX 100, A-1400 VIENNA, AUSTRIA SN 0029-5515 J9 NUCL FUSION JI Nucl. Fusion PD JUL PY 1997 VL 37 IS 7 BP 1033 EP 1035 DI 10.1088/0029-5515/37/7/410 PG 3 WC Physics, Fluids & Plasmas SC Physics GA XT873 UT WOS:A1997XT87300010 ER PT J AU Lumpkin, AH Yang, BX Chae, YC AF Lumpkin, AH Yang, BX Chae, YC TI Observations of bunch-lengthening effects in the APS 7-GeV storage ring SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 18th International Free-Electron-Laser Conference CY AUG 26-30, 1996 CL ROME, ITALY SP Italian Natl Agcy New Technol Energy & Environm DE storage ring; bunch length; streak camera AB Measurements of the bunch length and horizontal beam size at a bending magnet source point in the lattice versus single-bunch current have been done on the Advanced Photon Source (APS) 7-GeV storage ring. These data are relevant to issues (limits) of obtaining higher volume charge densities for storage-ring-based FELs. Bunch lengths from sigma(tau) similar to 25 to 70 ps were measured using a Hamamatsu C5680 dual-sweep streak camera. Additional complementary data on energy spread deduced from horizontal beam size at a dispersive point in the lattice were also tracked versus single-bunch current. Both optical synchrotron radiation (OSR) and X-ray synchrotron radiation (XSR) techniques were used. The significant bunch lengthening observed without a comparable horizontal size change (AE growth) is consistent with the potential-well distortion model rather than the predictions of a microwave instability calculation, With higher RF gap voltage, peak currents up to 400 A were observed. RP Lumpkin, AH (reprint author), ARGONNE NATL LAB,ADV PHOTON SOURCE,ARGONNE,IL 60439, USA. NR 8 TC 6 Z9 6 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUL 1 PY 1997 VL 393 IS 1-3 BP 50 EP 54 DI 10.1016/S0168-9002(97)00426-9 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XV603 UT WOS:A1997XV60300012 ER PT J AU Yu, LH BenZvi, I AF Yu, LH BenZvi, I TI High-gain harmonic generation of soft X-rays with the ''fresh bunch'' technique SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 18th International Free-Electron-Laser Conference CY AUG 26-30, 1996 CL ROME, ITALY SP Italian Natl Agcy New Technol Energy & Environm ID FEL; LASER AB We report numerical simulations (using the TDA code) and analytical verification of the generation of 64 Angstrom high-power soft X-rays from an exponential regime single-pass seeded FEL. The seed is generated in the FEL using the High-Gain Harmonic Generation (HGHG) technique combined with the ''fresh bunch'' technique. A seed pulse at 2944 Angstrom is generated by conventional laser techniques. The seed pulse produces an intense energy modulation of the rear part of a 1 GeV, 1245 A electron beam in a ''modulator'' wiggler. In the ''radiator'' wiggler (resonant at 64 Angstrom), the energy modulation creates beam density modulation followed by radiation of the 46th harmonic of the seed. We use a magnetic delay to position the 64 Angstrom radiation at the undisturbed front of the bunch to serve as a seed for a single pass, exponential growth FEL. After a 9 m long exponential section followed by a 7 m long tapered section the radiation power reaches 3.3 GW. RP Yu, LH (reprint author), BROOKHAVEN NATL LAB,NATL SYNCHROTRON LIGHT SOURCE DEPT,UPTON,NY 11973, USA. NR 11 TC 47 Z9 49 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUL 1 PY 1997 VL 393 IS 1-3 BP 96 EP 99 DI 10.1016/S0168-9002(97)00435-X PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XV603 UT WOS:A1997XV60300021 ER PT J AU Tatchyn, R Cremer, T AF Tatchyn, R Cremer, T TI Design considerations for a dual-etalon seed-light pre-filter for high-energy LCLS applications SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 18th International Free-Electron-Laser Conference CY AUG 26-30, 1996 CL ROME, ITALY SP Italian Natl Agcy New Technol Energy & Environm ID ELECTRON AB A flexible seed-light generation and coherence filtering scheme is considered for a 1.5 Angstrom FEL operating at 15 GeV. For R&D applications the configuration allows the FEL to be operated in a combination of Self-Amplified Spontaneous Emission (SASE) and Coherent Amplifier (CA) modes. Selected design and performance parameters are discussed. RP Tatchyn, R (reprint author), STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD SYNCHROTRON RADIAT LAB,STANFORD,CA 94309, USA. NR 11 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUL 1 PY 1997 VL 393 IS 1-3 BP 110 EP 113 DI 10.1016/S0168-9002(97)00439-7 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XV603 UT WOS:A1997XV60300024 ER PT J AU Tatchyn, R Cremer, T AF Tatchyn, R Cremer, T TI A fast analytical undulator model for realistic high-energy FEL simulations SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 18th International Free-Electron-Laser Conference CY AUG 26-30, 1996 CL ROME, ITALY SP Italian Natl Agcy New Technol Energy & Environm AB A number of leading FEL simulation codes used for modeling gain in the ultralong undulators required for SASE saturation in the < 100 Angstrom range employ simplified analytical models both for field and error representations. Although it is recognized that both the practical and theoretical validity of such codes could be enhanced by incorporating realistic undulator held calculations, the computational cost of doing this can be prohibitive, especially for point-to-point integration of the equations of motion through each undulator period. In this paper we describe a simple analytical model suitable for modeling realistic permanent magnet (PM), hybrid/PM, and non-PM undulator structures, and discuss selected techniques for minimizing computation time. RP Tatchyn, R (reprint author), STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD SYNCHROTRON RADIAT LAB,STANFORD,CA 94309, USA. NR 11 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUL 1 PY 1997 VL 393 IS 1-3 BP 114 EP 118 DI 10.1016/S0168-9002(97)00440-3 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XV603 UT WOS:A1997XV60300025 ER PT J AU Freund, HP Tatchyn, R AF Freund, HP Tatchyn, R TI Non-linear simulation of X-ray free-electron lasers using realistic wiggler models SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 18th International Free-Electron-Laser Conference CY AUG 26-30, 1996 CL ROME, ITALY SP Italian Natl Agcy New Technol Energy & Environm AB The non-linear simulation of X-ray free-electron lasers is dealt with using the non-wiggler-averaged MEDUSA simulation code and a realistic wiggler model built up from the contributions of permanent magnets in a Halbach configuration in conjunction with a model for a FODO lattice for enhanced focusing. The specific parameters of interest are relevant to the Linac Coherent Light Source (LCLS) design at SLAG and deals with a 15 GeV/5 kA electron beam, and a wiggler with a 3.0 cm period and an on-axis amplitude of approximately 12.7 kG which results in X-ray emission at wavelengths in the vicinity of 1.3 Angstrom. C1 STANFORD UNIV,STANFORD SYNCHROTRON RADIAT LAB,STANFORD,CA 94309. RP Freund, HP (reprint author), SCI APPLICAT INT CORP,1710 GODRIDGE DR,MCLEAN,VA 22102, USA. NR 12 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUL 1 PY 1997 VL 393 IS 1-3 BP 125 EP 128 DI 10.1016/S0168-9002(97)00442-7 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XV603 UT WOS:A1997XV60300027 ER PT J AU Goldstein, JC Nguyen, DC Sheffield, RL AF Goldstein, JC Nguyen, DC Sheffield, RL TI Theoretical study of the design and performance of a high-gain, high-extraction-efficiency FEL oscillator SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 18th International Free-Electron-Laser Conference CY AUG 26-30, 1996 CL ROME, ITALY SP Italian Natl Agcy New Technol Energy & Environm ID CEBAF AB We present the results of theoretical and simulation studies of the design and performance of a new type of FEL oscillator. This device, known by the acronym RAFEL for Regenerative Amplifier Free-Electron Laser, will be constructed in the space presently occupied by the Advanced FEL (AFEL) at Los Alamos, and will be driven by an upgraded (to higher average power) version of the present AFEL linac. In order to achieve a long-time-averaged optical output power of similar to 1 kW using an electron beam with an average power of similar to 20 kW, a rather high extraction efficiency eta similar to 5% is required. We have designed a 2 m long undulator to attain this goal; the first meter is untapered and provides high gain while the second meter is linearly tapered in magnetic field amplitude to provide high extraction efficiency in the standard K-M-R manner. Two-plane focusing and linear polarization of the undulator are assumed. Electron-beam properties from PARMELA simulations of the AFEL accelerator were used in the design. A large saturated gain, similar to 500, requires a very small optical feedback to keep the device operating at steady state. However, the large gain leads to distorted optical modes which require two and three-dimensional simulations to adequately treat diffraction effects. This FEL will be driven by 17 MeV electrons and will operate in the 16 mu m spectral region. RP Goldstein, JC (reprint author), LOS ALAMOS NATL LAB, GRP XPA, MS B259, LOS ALAMOS, NM 87545 USA. NR 8 TC 15 Z9 15 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUL 1 PY 1997 VL 393 IS 1-3 BP 137 EP 141 DI 10.1016/S0168-9002(97)00445-2 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XV603 UT WOS:A1997XV60300030 ER PT J AU Kim, KJ AF Kim, KJ TI Critical review of high-gain X-ray-FEL experiments SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 18th International Free-Electron-Laser Conference CY AUG 26-30, 1996 CL ROME, ITALY SP Italian Natl Agcy New Technol Energy & Environm ID FREE-ELECTRON-LASER; SHORT-WAVELENGTH FELS; TESLA-TEST-FACILITY; SCALING FUNCTION; AMPLIFIERS; UNDULATOR; SLAC; PERFORMANCE; RADIATION; EMITTANCE AB Exerimental efforts towards achieving the intense, coherent X-rays via the self-amplified-spontaneous-emission are reviewed, with particular attention to the development of critical components. RP Kim, KJ (reprint author), ERNEST ORLANDO LAWRENCE BERKELEY NATL LAB,1 CYCLOTRON RD,MS 71-259,BERKELEY,CA 94720, USA. NR 45 TC 7 Z9 7 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUL 1 PY 1997 VL 393 IS 1-3 BP 147 EP 151 DI 10.1016/S0168-9002(97)00447-6 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XV603 UT WOS:A1997XV60300032 ER PT J AU Kim, KJ AF Kim, KJ TI Start-up noise in 3-D self-amplified spontaneous emission SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 18th International Free-Electron-Laser Conference CY AUG 26-30, 1996 CL ROME, ITALY SP Italian Natl Agcy New Technol Energy & Environm ID FREE-ELECTRON LASER AB We discuss the effective start-up noise in Self-Amplified Spontaneous Emission (SASE), taking into account the finite angular spread as well as the size of the electron beam. The results obtained here generalize those obtained previously in the case of parallel beams, and clarify the role of the electron phase space distribution in the SASE start-up. RP Kim, KJ (reprint author), ERNEST ORLANDO LAWRENCE BERKELEY NATL LAB,1 CYCLOTRON RD,MS 71-259,BERKELEY,CA 94720, USA. NR 12 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUL 1 PY 1997 VL 393 IS 1-3 BP 167 EP 169 DI 10.1016/S0168-9002(97)00452-X PG 3 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XV603 UT WOS:A1997XV60300036 ER PT J AU Lumpkin, AH AF Lumpkin, AH TI On the path to the next generation of light sources SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 18th International Free-Electron-Laser Conference CY AUG 26-30, 1996 CL ROME, ITALY SP Italian Natl Agcy New Technol Energy & Environm ID RADIATION AB At the Fourth Generation Light Source Workshop in January 1996, storage-ring-based FELs and linac-based FELs were considered for VUV/soft X-ray and hard X-ray (lambda similar to 1 Angstrom) photon production respectively. The general requirements of a diffraction-limited source - bunch lengths less than 1 ps (100 fs in case of the linac-based source), coherence, and a brightness at several orders of magnitude higher than the third-generation sources - were among the features discussed. Examples of progress in demonstrations, measurements, or calculations that support research towards these areas are cited. These range from the 50 fs bunch length measurement at low current in a linac to few-mu rad divergence measurements on a 7 GeV storage ring. The possible extension of transition radiation-beam characterization techniques to nonintercepting diffraction radiation is briefly addressed as well. RP Lumpkin, AH (reprint author), ARGONNE NATL LAB,ADV PHOTON SOURCE,ARGONNE,IL 60439, USA. NR 17 TC 6 Z9 6 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUL 1 PY 1997 VL 393 IS 1-3 BP 170 EP 177 DI 10.1016/S0168-9002(97)00453-1 PG 8 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XV603 UT WOS:A1997XV60300037 ER PT J AU Sheffield, RL AF Sheffield, RL TI Electron beamline design for the Los Alamos National Laboratory 1kW FEL SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 18th International Free-Electron-Laser Conference CY AUG 26-30, 1996 CL ROME, ITALY SP Italian Natl Agcy New Technol Energy & Environm AB This paper describes the electron beam simulations for a 1 kW average power FEL. The experiment utilizes the existing AFEL accelerator. An expected 6% total efficiency of electron beam power to optical power gives 17 kW of electron beam power for I kW of optical power. A constraint on the beamline design is that the FEL electron beamline and optical components must fit on the existing AFEL 6 ft long optical table. The components include electron beam diagnostics, a 2 m long wiggler, bending magnets, and optical feedback components. The electron beam design point is 300 A peak current. 17 MeV energy, 7.5 pi mm-mrad effective normalized rms emittance and 6 nC micropulse charge. The electron beamline will have greater than 99% transmission. The wiggler will have weak (natural) two-plane focusing to maintain the electron beam size in the long wiggler. The beamline after the wiggler has to transport a beam with a 14-18 MeV energy spread and an average energy of 16 MeV. RP Sheffield, RL (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87544, USA. NR 2 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUL 1 PY 1997 VL 393 IS 1-3 BP 204 EP 209 DI 10.1016/S0168-9002(97)00466-X PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XV603 UT WOS:A1997XV60300044 ER PT J AU Graves, WS AF Graves, WS TI Gain and startup conditions for the BNL visible FEL oscillator experiment SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 18th International Free-Electron-Laser Conference CY AUG 26-30, 1996 CL ROME, ITALY SP Italian Natl Agcy New Technol Energy & Environm ID FREE-ELECTRON LASER AB The Visible FEL oscillator experiment at BNL is designed to lase at 530 nm using the 50 MeV high-brightness ATF electron beam and a micro-undulator of 8.8 mm period. The relatively low energy and short wavelength of this FEL require a high-quality electron beam. In this paper, we study the necessary electron beam requirements via a one-dimensional first-order simulation method. This method takes into account the finite length of the micropulse and the bandwidth of the spontaneous emission. It assumes a long electron pulse, weak optical fields, and low gain. For our experiment, startup time is of particular concern because of the limited length of the macropulse, The simulation method is extended to include the effects of emittance and energy spread. The expected gain and startup conditions for different beam parameters are compared with measured parameters. Scaling of gain versus beam parameters is examined and an experiment is proposed to verify these results. RP Graves, WS (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUL 1 PY 1997 VL 393 IS 1-3 BP 210 EP 215 DI 10.1016/S0168-9002(97)00467-1 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XV603 UT WOS:A1997XV60300045 ER PT J AU Kim, KJ AF Kim, KJ TI Can a free-electron laser operate with a broad momentum spread? SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 18th International Free-Electron-Laser Conference CY AUG 26-30, 1996 CL ROME, ITALY SP Italian Natl Agcy New Technol Energy & Environm AB Recently, a method to operate a free-electron laser with electron beams having a broad energy spread was proposed in which a device for redistributing the electrons' phase according to their momenta is introduced in the middle of the undulator. By properly taking into account the contributions from electrons near the edge of the phase space, it is shown that the proposed scheme does not work. RP Kim, KJ (reprint author), ERNEST ORLANDO LAWRENCE BERKELEY NATL LAB,1 CYCLOTRON RD,MS 71-259,BERKELEY,CA 94720, USA. NR 3 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUL 1 PY 1997 VL 393 IS 1-3 BP 234 EP 236 DI 10.1016/S0168-9002(97)00481-6 PG 3 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XV603 UT WOS:A1997XV60300050 ER PT J AU Shvets, G Wurtele, JS AF Shvets, G Wurtele, JS TI Pulse-shaping in short-pulse FEL oscillators using multiple resonators SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 18th International Free-Electron-Laser Conference CY AUG 26-30, 1996 CL ROME, ITALY SP Italian Natl Agcy New Technol Energy & Environm ID FREE-ELECTRON LASER AB A novel method is proposed for the efficient production of optical pulses that are shorter than a slippage length. The concept uses short electron bunches and a multiple cavity FEL oscillator configuration. C1 UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. RP Shvets, G (reprint author), PRINCETON UNIV,PRINCETON PLASMA PHYS LAB,POB 451,PRINCETON,NJ 08543, USA. RI wurtele, Jonathan/J-6278-2016 OI wurtele, Jonathan/0000-0001-8401-0297 NR 7 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUL 1 PY 1997 VL 393 IS 1-3 BP 237 EP 241 DI 10.1016/S0168-9002(97)00483-X PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XV603 UT WOS:A1997XV60300051 ER PT J AU Nguyen, DC Fortgang, CM Goldstein, JC KinrossWright, JM Sheffield, RL AF Nguyen, DC Fortgang, CM Goldstein, JC KinrossWright, JM Sheffield, RL TI Synchronously injected amplifiers, a novel approach to high-average-power FEL SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 18th International Free-Electron-Laser Conference CY AUG 26-30, 1996 CL ROME, ITALY SP Italian Natl Agcy New Technol Energy & Environm ID FREE-ELECTRON LASER AB Two new FEL ideas based on synchronously injected amplifiers are described. Both of these rely on the synchronous injection of the optical signal into a high-gain, high-efficiency tapered wiggler. The first concept, called Regenerative Amplifier FEL (RAFEL), uses an optical feedback loop to provide a coherent signal at the wiggler entrance so that the optical power can reach saturation rapidly. The second idea requires the use of a uniform wiggler in the feedback loop to generate light that can be synchronously injected back into the first wiggler. The compact advanced FEL is being modified to implement the RAFEL concept. We describe future operation of the advanced FEL at high average current and discuss the possibility of generating 1 kW average power. RP Nguyen, DC (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 10 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUL 1 PY 1997 VL 393 IS 1-3 BP 252 EP 256 DI 10.1016/S0168-9002(97)00666-9 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XV603 UT WOS:A1997XV60300054 ER PT J AU Shvets, G Wurtele, JS AF Shvets, G Wurtele, JS TI Temporal and spectral structure of an FEL oscillator during start-up SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 18th International Free-Electron-Laser Conference CY AUG 26-30, 1996 CL ROME, ITALY SP Italian Natl Agcy New Technol Energy & Environm ID FREE-ELECTRON-LASER AB A previously developed Green's function technique for analyzing the time evolution of low-gain FEL oscillators is applied to the study of the start-up of oscillators from random beam noise. These calculations describe the evolution of the total radiation power and the spectral power as a function of pass number. The theory suggests that an estimate of the linear gain of an oscillator during start-up, as well as the noise level on the electron beam, can be inferred from a measurement of the position of the spectral peak of the FEL output. Analytical results are obtained for electron beams much longer than the slippage distance. A computationally efficient method for the spectral analysis of finite pulse FEL oscillators is described. C1 UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. RP Shvets, G (reprint author), PRINCETON PLASMA PHYS LAB,POB 451,PRINCETON,NJ 08543, USA. RI wurtele, Jonathan/J-6278-2016 OI wurtele, Jonathan/0000-0001-8401-0297 NR 7 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUL 1 PY 1997 VL 393 IS 1-3 BP 273 EP 276 DI 10.1016/S0168-9002(97)00491-9 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XV603 UT WOS:A1997XV60300059 ER PT J AU Faatz, B Fawley, W Pierini, P Reiche, S Travish, G Whittum, D Wurtele, J AF Faatz, B Fawley, W Pierini, P Reiche, S Travish, G Whittum, D Wurtele, J TI TDA3D: Updates and improvements to the widely used three-dimensional free electron laser simulation SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 18th International Free-Electron-Laser Conference CY AUG 26-30, 1996 CL ROME, ITALY SP Italian Natl Agcy New Technol Energy & Environm AB TDA3D is a widely distributed and often used Free Electron Laser (FEL) simulation code. While a number of versions of TDA exist, this paper describes the official version which is well tested and supported. We describe the capabilities of the code emphasizing recent improvements and revisions. TDA3D is a steady-state (time-independent) amplifier code. The code self-consistently solves, after averaging over a wiggler period, the paraxial wave equation for the radiation field and the Lorentz equations of motion for the electrons. The paraxial wave equation includes diffraction and optical guiding. The calculation of the electron beam motion takes into account longitudinal bunching and transverse betatron oscillations, so that emittance, energy spread, and external focusing can be properly modeled. Recent additions to the simulation include the ability to model natural wiggler focusing in one or both planes, alternating gradient quadrupoles or sextupoles, and ion channels. The initial loading of the electron distribution can be controlled to allow for matching into focusing channels, improved quiet starts (non-correlated phase-space distributions), and arbitrary energy spread. C1 UNIV CALIF LOS ANGELES,DEPT PHYS,LOS ANGELES,CA 90095. DESY,D-22607 HAMBURG,GERMANY. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. IST NAZL FIS NUCL,I-20133 MILAN,ITALY. STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94025. RI Travish, Gil/H-4937-2011; Pierini, Paolo/J-3555-2012; wurtele, Jonathan/J-6278-2016 OI Travish, Gil/0000-0002-4787-0949; Pierini, Paolo/0000-0002-3062-6181; wurtele, Jonathan/0000-0001-8401-0297 NR 7 TC 5 Z9 5 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUL 1 PY 1997 VL 393 IS 1-3 BP 277 EP 279 DI 10.1016/S0168-9002(97)00492-0 PG 3 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XV603 UT WOS:A1997XV60300060 ER PT J AU Caplan, M Valentini, M Verhoeven, A Urbanus, W Tulupov, A AF Caplan, M Valentini, M Verhoeven, A Urbanus, W Tulupov, A TI Extrapolation of the FOM 1 MW free-electron maser to a multi-megawatt millimeter microwave source SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 18th International Free-Electron-Laser Conference CY AUG 26-30, 1996 CL ROME, ITALY SP Italian Natl Agcy New Technol Energy & Environm ID 200-GHZ; 1-MW; FEM AB A Free-Electron Maser is now under test at the FOM Institute (Rijnhuizen, Netherlands) with the goal of producing 1 MW long pulse to CW microwave output in the range 130-250 GHz with wall plug efficiencies of 60%. An extrapolated version of this device is proposed, which by scaling up beam current and voltage, would produce microwave power levels of up to 5 MW CW, thus reducing the cost per kilowatt and increasing the power per module. This would allow for practical applications in such diverse areas such as space power beaming, heating effusion plasmas and heating of high Mach number wind tunnels. C1 FOM INST PLASMA PHYS RIJNHUIZEN,NIEUWEGEIN,NETHERLANDS. SOLITON NTT RES CTR,MOSCOW,RUSSIA. RP Caplan, M (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,LIVERMORE,CA 94551, USA. NR 5 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUL 1 PY 1997 VL 393 IS 1-3 BP 295 EP 299 DI 10.1016/S0168-9002(97)00496-8 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XV603 UT WOS:A1997XV60300064 ER PT J AU Freund, HP Yu, LH AF Freund, HP Yu, LH TI Comparison of wiggler-averaged and non-wiggler-averaged free-electron laser simulations SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 18th International Free-Electron-Laser Conference CY AUG 26-30, 1996 CL ROME, ITALY SP Italian Natl Agcy New Technol Energy & Environm AB Two distinct types of free-electron laser simulations are in general use. In ''wiggler-averaged'' simulation codes such as FRED and TDA, the Lorentz force equations are averaged over a wiggler period. A reduced orbit analysis is obtained requiring integration only of equations for the energy and ponderomotive phase for each electron. In contrast, ''non-wiggler-averaged'' such as MEDUSA use the complete three-dimensional Lorentz force equations. A direct comparison of the two techniques is discussed in this paper using the MEDUSA and TDA codes. C1 BROOKHAVEN NATL LAB,NATL SYNCHROTRON LIGHT SOURCE DEPT,UPTON,NY 11973. RP Freund, HP (reprint author), SCI APPLICAT INT CORP,MCLEAN,VA 22102, USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUL 1 PY 1997 VL 393 IS 1-3 BP 308 EP 311 DI 10.1016/S0168-9002(97)00499-3 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XV603 UT WOS:A1997XV60300067 ER PT J AU Brownell, JH Walsh, J Kirk, HG Fernow, RC Robertson, SH AF Brownell, JH Walsh, J Kirk, HG Fernow, RC Robertson, SH TI Smith-Purcell radiation from a 50 MeV beam SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 18th International Free-Electron-Laser Conference CY AUG 26-30, 1996 CL ROME, ITALY SP Italian Natl Agcy New Technol Energy & Environm AB A 50 MeV electron beam and a 1 mm period, 5 degrees blaze, echelle grating have been used to produce radiation in the mid-infrared spectral region. The emission is highly collimated and forward-directed. The intensity level in the few ps pulse (2 nJ/sr) indicates a degree of coherent enhancement. C1 BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. UNIV COLORADO,DEPT ASTROPHYS & GEOPHYS,BOULDER,CO 80309. RP Brownell, JH (reprint author), DARTMOUTH COLL,DEPT PHYS & ASTRON,HANOVER,NH 03755, USA. NR 4 TC 11 Z9 11 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUL 1 PY 1997 VL 393 IS 1-3 BP 323 EP 325 DI 10.1016/S0168-9002(97)00502-0 PG 3 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XV603 UT WOS:A1997XV60300070 ER PT J AU Shvets, G Wurtele, JS AF Shvets, G Wurtele, JS TI SASE in plasmas: Analysis and simulation of Raman backscatter from noise SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 18th International Free-Electron-Laser Conference CY AUG 26-30, 1996 CL ROME, ITALY SP Italian Natl Agcy New Technol Energy & Environm ID DRIVEN; FEL AB Theoretical techniques from free-electron laser research are modified for analytical and numerical investigations of Raman Backscatter (RES) in plasmas. The physical system consists of an intense short laser pulse propagating through an underdense plasma. The analogy with the free-electron laser is essentially a correspondence of the plasma electrons with the electron beam, the incident laser pulse with the wiggler and the backscatter pulse with the radiation. This approach has significant advantages over previous theoretical treatments, which were mostly linear fluid theories, and particle-in-cell simulations which are computationally expensive. The problem of backscatter from noise? which is the RES equivalent of SASE, is analyzed and compared to experimental observations. C1 UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94270. RP Shvets, G (reprint author), PRINCETON PLASMA PHYS LAB,POB 451,PRINCETON,NJ 08543, USA. RI wurtele, Jonathan/J-6278-2016 OI wurtele, Jonathan/0000-0001-8401-0297 NR 9 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUL 1 PY 1997 VL 393 IS 1-3 BP 371 EP 375 DI 10.1016/S0168-9002(97)00515-9 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XV603 UT WOS:A1997XV60300080 ER PT J AU Fortgang, CM AF Fortgang, CM TI A pure permanent magnet two plane focusing tapered wiggler for a high average power FEL SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 18th International Free-Electron-Laser Conference CY AUG 26-30, 1996 CL ROME, ITALY SP Italian Natl Agcy New Technol Energy & Environm ID UNDULATOR SCHEMES AB A high-average power FEL is under construction at Los Alamos. The FEL will have aspects of both an oscillator and a SASE (self-amplified spontaneous emission) device. That is, a high-gain and high-extraction efficiency wiggler will be used with a very low-Q optical resonator. FEL simulations reveal that a tapered wiggler with two-plane focusing is required to obtain desired performance. The wiggler is comprised of a 1 m long untapered section followed by a Im tapered section. The taper is achieved with the magnetic gap and not the wiggler period which is constant at 2 cm. The gap is tapered from 5.9 to 8.8 mm. The gap, rather than the period, is tapered to avoid vignetting of the 16 mu m optical beam. Two-plane focusing is necessary to maintain high current density and thus high gain through out the 2 m long wiggler. Several magnetic designs have been considered for the wiggler. The leading candidate approach is a pure permanent wiggler with pole faces that are cut to roughly approximate the classical parabolic pole face design. Focusing is provided by the sextupole component of the wiggler magnetic field and is often called ''natural'' or ''betatron'' focusing. Details of the design will be presented. RP Fortgang, CM (reprint author), LOS ALAMOS NATL LAB,MS H-851,LOS ALAMOS,NM 87545, USA. NR 10 TC 7 Z9 7 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUL 1 PY 1997 VL 393 IS 1-3 BP 385 EP 388 DI 10.1016/S0168-9002(97)00519-6 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XV603 UT WOS:A1997XV60300083 ER PT J AU Qiu, X Catravas, P Babzien, M BenZvi, I Fang, JM Graves, W Liu, Y Malone, R Mastovsky, I Segalov, Z Sheehan, J Stoner, R Wang, XJ Wurtele, JS AF Qiu, X Catravas, P Babzien, M BenZvi, I Fang, JM Graves, W Liu, Y Malone, R Mastovsky, I Segalov, Z Sheehan, J Stoner, R Wang, XJ Wurtele, JS TI Experiments in nonperturbative electron beam characterization with the MIT microwiggler at the accelerator test facility at BNL SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 18th International Free-Electron-Laser Conference CY AUG 26-30, 1996 CL ROME, ITALY SP Italian Natl Agcy New Technol Energy & Environm ID EMITTANCE MEASUREMENTS; UNDULATOR; RADIATION AB We report first measurements of a single-shot method through which the properties of an electron beam at linac energies may be studied using the spontaneous emission of a micro-wiggler, The setup is simple and the measurement efficient. A simple set of scaling laws describe the natural line width, energy spread and divergence broadening of spontaneous emission in a narrow bandwidth radiation cone. A systematic series of experiments were performed with the MIT Microwiggler at the Accelerator Test Facility at BNL which demonstrated the response of the cone to changes in the beam quality. Estimates of divergence were obtained from the measurements of the radiation cone. C1 MIT,ELECT RES LAB,CAMBRIDGE,MA 02139. BROOKHAVEN NATL LAB,UPTON,NY 11973. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. COLUMBIA UNIV,NEW YORK,NY 10027. RI wurtele, Jonathan/J-6278-2016 OI wurtele, Jonathan/0000-0001-8401-0297 NR 10 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUL 1 PY 1997 VL 393 IS 1-3 BP 484 EP 489 DI 10.1016/S0168-9002(97)00576-7 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XV603 UT WOS:A1997XV60300104 ER PT J AU Carlsten, BE Goldstein, JC AF Carlsten, BE Goldstein, JC TI Emittance growth of a short electron bunch in circular motion SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 18th International Free-Electron-Laser Conference CY AUG 26-30, 1996 CL ROME, ITALY SP Italian Natl Agcy New Technol Energy & Environm AB A short electron bunch undergoing circular motion produces space-charge forces that do not decrease with increasing bunch energy, unlike those induced by straight-line motion. These energy-independent forces can be separated into a noninertial space-charge force and a coherent synchrotron radiation force. These forces result in an energy spread in the bunch and can lead to a potentially large emittance growth. These effects can take place in both (1) bunch compression systems used to increase the peak current and (2) the wiggler itself. Numerical estimates of the emittance growth in a wiggler for a 1 ps long, 1 mm radius, 1 nC electron bunch can be as large as 0.1 pi mm mrad per wiggle period; the energy spread can grow as much as 30 keV per wiggle period. These types of beam quality degradation may become significant for future, short-wavelength free-electron lasers requiring high-brightness electron beams, especially for self-amplified spontaneous emission operation. RP Carlsten, BE (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 7 TC 8 Z9 8 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUL 1 PY 1997 VL 393 IS 1-3 BP 490 EP 493 DI 10.1016/S0168-9002(97)00551-2 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XV603 UT WOS:A1997XV60300105 ER PT J AU Dattoli, G Lumpkin, AH Voykov, GK Yang, BX AF Dattoli, G Lumpkin, AH Voykov, GK Yang, BX TI Criteria for derivation of e-beam emittances using undulator radiation SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 18th International Free-Electron-Laser Conference CY AUG 26-30, 1996 CL ROME, ITALY SP Italian Natl Agcy New Technol Energy & Environm AB We present general considerations on the possibility of extracting the e-beam emittance values from the undulator brightness data. The most important result of the present analysis is that it is not possible to obtain a one-to-one correspondence between the point values of the brightness and emittances. Nevertheless, it is shown that there exists an uncertainty region of emittance values which can be connected to give the interval of the perturbed brightness. The extension of this region depends on the accuracy of the brightness estimation. The paper is devoted to such an analysis and to a discussion of the intrinsic limitations of the method. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. RP Dattoli, G (reprint author), ENEA,DIPARTIMENTO INNOVAZ,DIV FIS APPLICATA,CTR RIC FRASCATI,CP 65,I-00044 FRASCATI,ROME,ITALY. NR 8 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUL 1 PY 1997 VL 393 IS 1-3 BP 500 EP 503 DI 10.1016/S0168-9002(97)00553-6 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XV603 UT WOS:A1997XV60300107 ER PT J AU Nguyen, DC AF Nguyen, DC TI Coherent Smith-Purcell radiation as a diagnostic for subpicosecond electron bunch length SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 18th International Free-Electron-Laser Conference CY AUG 26-30, 1996 CL ROME, ITALY SP Italian Natl Agcy New Technol Energy & Environm ID RELATIVISTIC ELECTRONS AB We suggest a novel technique of measuring subpicosecond electron bunch length based on coherent Smith-Purcell radiation (SPR). We predict an electron beam traversing near the surface of a grating will emit coherent SPR if the electron bunch length is less than the grating period. The coherent SPR will be emitted at large angles with respect to the beam propagation direction and its intensity will be greatly enhanced compared to incoherent SPR. By measuring the angular position of the coherent SPR peak or the ratio of its intensity relative to the incoherent SPR, we can determine the electron bunch length. This technique appears to be scaleable to femtosecond electron bunch measurements. RP Nguyen, DC (reprint author), LOS ALAMOS NATL LAB,MAIL STOP H851,LOS ALAMOS,NM 87545, USA. NR 10 TC 14 Z9 14 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUL 1 PY 1997 VL 393 IS 1-3 BP 514 EP 518 DI 10.1016/S0168-9002(97)00556-1 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XV603 UT WOS:A1997XV60300110 ER PT J AU Kim, KJ AF Kim, KJ TI Gamma-Gamma collider based on Compton backscattering SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 18th International Free-Electron-Laser Conference CY AUG 26-30, 1996 CL ROME, ITALY SP Italian Natl Agcy New Technol Energy & Environm AB We discuss the principles and issue for gamma gamma colliders based on Compton backscattering of high-power laser beams of TeV electron beams in future e(+)e(-) linear colliders. RP Kim, KJ (reprint author), UNIV CALIF BERKELEY,ERNEST ORLANDO LAWRENCE BERKELEY NATL LAB,1 CYCLOTRON RD,MS 71-259,BERKELEY,CA 94720, USA. NR 19 TC 1 Z9 1 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUL 1 PY 1997 VL 393 IS 1-3 BP 530 EP 535 DI 10.1016/S0168-9002(97)00558-5 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XV603 UT WOS:A1997XV60300113 ER PT J AU Antolak, AJ Morse, DH Heikkinen, DW Roberts, ML Bench, GS AF Antolak, AJ Morse, DH Heikkinen, DW Roberts, ML Bench, GS TI In situ characterization of micron-scale particles by nuclear microscopy SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 5th International Conference on Nuclear Microprobe Technology and Applications (ICNMTA) CY NOV 11-15, 1996 CL SANTA FE, NM SP Sandia Natl Labs, Los Alamos Natl Lab, Lawrence Livermore Natl lab ID FLY-ASH PARTICLES; PIXE ANALYSIS; ION AB Nuclear microscopy is well suited for analyzing large particle populations as well as individual particles of interest in various types of collection samples. Unlike some commonly used in situ techniques, nuclear microscopy can quantitatively characterize particles embedded within the sample or particles that are too small to be reliably removed from their collection media. Additional advantages include its capability for the detection of minor and trace elements, its capability to simultaneously analyze multiple elements with little or no prior sample preparation, and its potential for automated analyses. Preliminary data are presented of particle size and composition measurements conducted on air filters. The potential of applying nuclear microscopy to the cataloging of micron-scale cometary remnants captured in low density aerogel collectors is also explored. Because of its importance to a variety of collection programs, an innovative high-throughput ion beam imaging and analysis system is being jointly developed by Sandia and Lawrence Livermore national laboratories for rapid quantitative particle characterization. (C) 1997 Elsevier Science B.V. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP Antolak, AJ (reprint author), SANDIA NATL LABS,LIVERMORE,CA 94550, USA. NR 11 TC 3 Z9 3 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD JUL PY 1997 VL 130 IS 1-4 BP 211 EP 218 DI 10.1016/S0168-583X(97)00372-8 PG 8 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XZ017 UT WOS:A1997XZ01700039 ER PT J AU Formenti, P Breese, MBH Connell, SH Doyle, BP Drummond, ML Machi, IZ Maclear, RD Schaaff, P Sellschop, JPF Bench, G SiderasHaddad, E Antolak, A Morse, D AF Formenti, P Breese, MBH Connell, SH Doyle, BP Drummond, ML Machi, IZ Maclear, RD Schaaff, P Sellschop, JPF Bench, G SiderasHaddad, E Antolak, A Morse, D TI Heavy ion and proton beams in high resolution imaging of a fungi spore specimen using STIM tomography SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 5th International Conference on Nuclear Microprobe Technology and Applications (ICNMTA) CY NOV 11-15, 1996 CL SANTA FE, NM SP Sandia Natl Labs, Los Alamos Natl Lab, Lawrence Livermore Natl lab ID MICROTOMOGRAPHY; MICROSCOPY AB Scanning transmission ion microscopy (STIM) tomography as a 3-D imaging technique has been shown to have a range of applications. The energy of the transmitted ion is detected with nearly 100% efficiency as a function of position in the transverse plane. The parameters relating to transmitted ion energy loss in the sample are imaged with statistics given by the energy loss process rather than Poisson counting statistics. This enables very fast collection of a set of relatively noise-free 2-D images. Each image is collected after a small rotation of the sample, and a complete 3-D representation of the sample may be tomographically reconstructed. The small beam currents necessary mean that the technique is non-destructive. One of the fields where these non-destructive 3-D density structure maps are particularly useful is in the analysis of biological tissue. The variation of energy loss with projectile atomic number may be exploited to tune the energy loss contrast to the size and density of the sample (heavy ion STIM). This work develops this point, and applies it to the imaging of the microscopic structure of a 90 mu m diameter mycorrhiza fungi spore. This specimen has been imaged non-destructively in 3-D using both a 36 MeV C-12 beam and a 2.2 MeV proton beam, both with a spatial resolution of about 1 mu m. The gain in contrast in the carbon median energy loss maps was dramatic as expected. The corresponding improvement in the tomogram was found to be visible but less dramatic. The tomographic sections as well as the median energy loss maps of the vesicular-arbuscular mycorrhiza fungi spore clearly show the internal structure. Wall morphology data has relevance to germination behaviour of the spores. C1 UNIV WITWATERSRAND,SCHONLAND RES CTR NUCL SCI,ZA-2050 WITWATERSRAND,JOHANNESBURG,SOUTH AFRICA. LAWRENCE LIVERMORE NATL LAB,CTR ACCELERATOR MASS SPECTROMETRY,DEPT PHYS,LIVERMORE,CA 94550. SANDIA NATL LABS,LIVERMORE,CA 94551. RI Breese, Mark/G-2068-2012; Connell, Simon/F-2962-2015 OI Connell, Simon/0000-0001-6000-7245 NR 18 TC 5 Z9 5 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD JUL PY 1997 VL 130 IS 1-4 BP 230 EP 236 DI 10.1016/S0168-583X(97)00051-7 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XZ017 UT WOS:A1997XZ01700042 ER PT J AU SiderasHaddad, E Heikkinen, D Connell, SH Caffee, MW Roberts, ML Bench, GS Morse, D Meike, A Bourcier, W AF SiderasHaddad, E Heikkinen, D Connell, SH Caffee, MW Roberts, ML Bench, GS Morse, D Meike, A Bourcier, W TI Three-dimensional elastic recoil detection analysis of hydrogen in materials for use in the Yucca Mountain nuclear waste repository SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 5th International Conference on Nuclear Microprobe Technology and Applications (ICNMTA) CY NOV 11-15, 1996 CL SANTA FE, NM SP Sandia Natl Labs, Los Alamos Natl Lab, Lawrence Livermore Natl lab AB An original system has been developed capable of performing three-dimensional Energy Recoil Detection Analysis (ERDA) of hydrogen in materials with scanned and finely focused heavy-ion beams. The technique is being used at the Lawrence Livermore National Laborotory Multi-user Tandem Laboratory to measure the hydrogen content in materials under consideration for use in the Yucca Mountain nuclear waste repository. From the measurement of hydrogen concentration profiles we can extrapolate reaction rates. A critical problem is the rate of dissolution of the glass being used. The HI-ERDA (Heavy Ion-ERDA) technique can provide this information which is needed in order to predict the overall rate of nuclear waste glass degradation in a waste repository. The technique is calibrated using a silicon wafer implanted with a known concentration of hydrogen. The sample is illuminated by a Cl-35 ion beam that is micro-scanned across the sample. From these measurements we reconstruct three dimensional profiles of hydrogen content which can then be used to obtain spatially-resolved hydrogen depth profiles. (C) 1997 Elsevier Science B.V. C1 WITS UNIV,SCHONLAND CTR NUCL SCI,JOHANNESBURG,SOUTH AFRICA. SANDIA NATL LABS,LIVERMORE,CA. RP SiderasHaddad, E (reprint author), LAWRENCE LIVERMORE NATL LAB,CTR ACCELERATOR MASS SPECTROMETRY,POB 808,L-397,LIVERMORE,CA 94550, USA. RI Connell, Simon/F-2962-2015; Caffee, Marc/K-7025-2015 OI Connell, Simon/0000-0001-6000-7245; Caffee, Marc/0000-0002-6846-8967 NR 5 TC 3 Z9 3 U1 2 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD JUL PY 1997 VL 130 IS 1-4 BP 259 EP 263 DI 10.1016/S0168-583X(97)00301-7 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XZ017 UT WOS:A1997XZ01700047 ER PT J AU Bench, G Freeman, S Roberts, M SiderasHaddad, E AF Bench, G Freeman, S Roberts, M SiderasHaddad, E TI The bioscience nuclear microscopy program at LLNL SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 5th International Conference on Nuclear Microprobe Technology and Applications (ICNMTA) CY NOV 11-15, 1996 CL SANTA FE, NM SP Sandia Natl Labs, Los Alamos Natl Lab, Lawrence Livermore Natl lab ID SPERM; MICROPROBE; LIVERMORE; ZINC AB Since initiation in mid 1994, a bioscience nuclear microscopy program at Livermore has enabled collaboration with bio-scientists on a variety of projects requiring quantitative elemental microanalysis. For microprobe analysis a combination of PIXE and STIM are typically used, respectively generating element distribution maps with micron scale spatial resolution, and projected densities and histological information with sub-micron spatial resolution. Current studies demonstrate the applicability of nuclear microscopy (particularly when combined with other analysis techniques) in environmental tracing, toxicology, carcinogenesis, and structural biology. The program currently uses similar to 10 percent of the available time on a 10 MV tandem accelerator that is also applied to a variety of Accelerator Mass Spectrometry and other microprobe programs. The completion of a dedicated nuclear microprobe system, using a 5 SDH NEC 1.7 MV tandem accelerator and employing several energy dispersive X-ray detectors to improve X-ray counting rates, promises increased accelerator access, greater sample throughput and continued expansion of the program. RP Bench, G (reprint author), LAWRENCE LIVERMORE NATL LAB,CTR ACCELERATOR MASS SPECTROMETRY,LIVERMORE,CA 94550, USA. RI Freeman, Stewart/C-3290-2012 OI Freeman, Stewart/0000-0001-6148-3171 NR 18 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD JUL PY 1997 VL 130 IS 1-4 BP 419 EP 425 DI 10.1016/S0168-583X(97)00235-8 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XZ017 UT WOS:A1997XZ01700072 ER PT J AU Horn, KM Dodd, PE Breese, MBH Doyle, BL AF Horn, KM Dodd, PE Breese, MBH Doyle, BL TI Verification of three-dimensional charge transport simulations using ion microbeams SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 5th International Conference on Nuclear Microprobe Technology and Applications (ICNMTA) CY NOV 11-15, 1996 CL SANTA FE, NM SP Sandia Natl Labs, Los Alamos Natl Lab, Lawrence Livermore Natl lab AB Optically targeted, ion microbeams provide a useful means of exposing individual structures within an integrated circuit to ionizing radiation. With this tool, calibrated, low damage, charge collection spectra can be measured from specific circuit structures without preceding ion damage to the structure or surrounding circuitry. This paper presents comparisons of calibrated, low damage, ion microbeam-based charge collection measurements and three-dimensional, charge transport simulations of charge collection for isolated n- and p-channel field effect transistors under conducting and non-conducting bias conditions. C1 UNIV OXFORD,DEPT PHYS,OXFORD OX1 3RH,ENGLAND. RP Horn, KM (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. RI Breese, Mark/G-2068-2012 NR 5 TC 6 Z9 6 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD JUL PY 1997 VL 130 IS 1-4 BP 470 EP 477 DI 10.1016/S0168-583X(97)00342-X PG 8 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XZ017 UT WOS:A1997XZ01700081 ER PT J AU Paxton, AH Schone, H Taylor, EW McKinney, S Doyle, BL AF Paxton, AH Schone, H Taylor, EW McKinney, S Doyle, BL TI Performance of an acousto-optic Bragg cell under ion microbeam irradiation SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 5th International Conference on Nuclear Microprobe Technology and Applications (ICNMTA) CY NOV 11-15, 1996 CL SANTA FE, NM SP Sandia Natl Labs, Los Alamos Natl Lab, Lawrence Livermore Natl lab AB An acousto-optic (AO) deflector composed of PbMoO4 was exposed to 4 MeV protons while operating under Bragg angle conditions. An ion beam in air of 1 mm width was directed normal to the crystal face and laser beam. Between exposures, the approximately 13 mm x 8.5 mm AO deflector was mechanically translated in two dimensions in front of the fixed ion beam. The AO diffraction efficiency was mapped and was observed to change as a function of ion beam location and dose rate. These effects are attributed to the induced change in the temperature distribution of the crystal, which changed the sonic velocity and refractive index. Similar effects were observed when the ion beam was directed at the acoustic transducer. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP Paxton, AH (reprint author), USAF,PHILLIPS LAB,VTMC,KIRTLAND AFB,NM 87117, USA. NR 4 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD JUL PY 1997 VL 130 IS 1-4 BP 539 EP 542 DI 10.1016/S0168-583X(97)00246-2 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XZ017 UT WOS:A1997XZ01700093 ER PT J AU Schone, H Walsh, D McGrath, RT Burkhart, JH Doyle, BL AF Schone, H Walsh, D McGrath, RT Burkhart, JH Doyle, BL TI Microbeam RBS on flat panel displays SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 5th International Conference on Nuclear Microprobe Technology and Applications (ICNMTA) CY NOV 11-15, 1996 CL SANTA FE, NM SP Sandia Natl Labs, Los Alamos Natl Lab, Lawrence Livermore Natl lab AB We have demonstrated the utility of microbeam-Rutherford BackScattering (mu-RBS) in spatially resolved studies of operational plasma effects on the interior surfaces of plasma flat panel displays manufactured by Photonics Imaging. The experiments were performed at the Sandia Nuclear microprobe using a 2.8 MeV He beam with an average beam spot size of less than 8 mu m. The interior surface of the top panes of the flat panels is composed of approximately 800 nm of MgO on top of a 2000 nm thick PbO layer. mu-RBS of sample panels operated under varying conditions measured changes in the surface MgO film thickness due to plasma erosion and redeposition as accurately as +/-1.5 nm. The high accuracy in the MgO thickness measurement was achieved by inferring the MgO thickness from the shift of the Pb front edge in the RBS spectrum. An estimate for the thickness accuracy as a function of the acquired statistics is presented. The surface of the flat panels' bottom panes is also comprised of MgO on top of PbO. However, troughs similar to 100 mu m wide by 10 mu m deep were partially filled with phosphor and cover the entire width of the surface. This leaves only 100 mu m long sections of MgO within the trough exposed. Using mu-RBS, we were able to analyze the surface composition of these regions. (C) 1997 Elsevier Science B.V. RP Schone, H (reprint author), SANDIA NATL LABS,POB 5800,MS 1056,ALBUQUERQUE,NM 87185, USA. NR 2 TC 3 Z9 3 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD JUL PY 1997 VL 130 IS 1-4 BP 543 EP 550 DI 10.1016/S0168-583X(97)00247-4 PG 8 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XZ017 UT WOS:A1997XZ01700094 ER PT J AU Schone, H Breese, MBH Lee, SR Briggs, RD Casalnuovo, SA Doyle, BL Drummond, TJ Fritz, IJ Hafich, MJ Vawter, GA AF Schone, H Breese, MBH Lee, SR Briggs, RD Casalnuovo, SA Doyle, BL Drummond, TJ Fritz, IJ Hafich, MJ Vawter, GA TI Dislocation imaging of an InAlGaAs opto-electronic modulator using IBICC SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 5th International Conference on Nuclear Microprobe Technology and Applications (ICNMTA) CY NOV 11-15, 1996 CL SANTA FE, NM SP Sandia Natl Labs, Los Alamos Natl Lab, Lawrence Livermore Natl lab ID BEAM-INDUCED CHARGE AB This paper presents Ion Beam Induced Charge Collection (IBICC) contrast images showing regions of differing charge collection efficiency within optoelectronic modulator devices. The experiments were carried out at the Sandia Nuclear Microprobe using 18 MeV carbon and 2 MeV helium ions. Lines of varying densities are observed to run along the different {110} directions which correlate with misfit dislocations within the 392 nm thick strained-layer superlattice quantum well of the modulator structure. Independent cross-sectional TEM studies and the electrical properties of the devices under investigation suggest the presence of threading dislocations in the active device region at a density of less than or similar to 10(6) cm(-2). However, no clear evidence of threading dislocations was observed in the IBICC images as they are possibly masked by the strong contrast of the misfit dislocations. Charge carrier transport within the modulator is used to explain the observed contrast. The different signal to noise levels and rates of damage of the incident ions are assessed. (C) 1997 Elsevier Science B.V. C1 UNIV OXFORD,NUCL PHYS LAB,OXFORD OX1,ENGLAND. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP Schone, H (reprint author), PHILLIPS LAB,3550 ABERDEEN AVE,KIRTLAND AFB,ALBUQUERQUE,NM, USA. RI Breese, Mark/G-2068-2012 NR 4 TC 4 Z9 4 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD JUL PY 1997 VL 130 IS 1-4 BP 551 EP 556 DI 10.1016/S0168-583X(97)00248-6 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XZ017 UT WOS:A1997XZ01700095 ER PT J AU Hickmott, DD Herrin, JM Abell, R George, M Stimac, J Gauerke, ER Denniston, RF AF Hickmott, DD Herrin, JM Abell, R George, M Stimac, J Gauerke, ER Denniston, RF TI Environmental applications of the LANL nuclear microprobe SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 5th International Conference on Nuclear Microprobe Technology and Applications (ICNMTA) CY NOV 11-15, 1996 CL SANTA FE, NM SP Sandia Natl Labs, Los Alamos Natl Lab, Lawrence Livermore Natl lab ID FLY-ASH PARTICLES; PIXE ANALYSIS; TREE-RINGS; MICROANALYSIS; SHELLS; COAL; EFFICIENCY; MICROSCOPE; SCIENCES; ELEMENTS AB The LANL nuclear microprobe has been used to study the distributions of trace elements (TE) of environmental interest including: (1) metals in coal and fly ash, (2) Pb in the Bandelier Tuff (BT), (3) Ba in tree rings, (4) Mn, Fe, Sr and Y in Yucca Mountain calcites. These studies illustrate environmental problems that can be addressed using nuclear microprobes. Micro-PIXE (MP) analyses with 5-10 micrometer spatial resolution provide constraints on processes that redistribute contaminants in the environment, and hence may help answer environmental problems where fine-scale chemical records are important. MP analyses of particulates in coal and ash show that pyrite contains As, Se, Hg and Pb; macerals contain Cr, halogens and S; cenospheres contain As, Se and Ni; and hematite ash contains Ni and As. Understanding these elemental modes of occurrence allows prediction of metal behavior in boilers and may enhance compliance with the Clean Air Act Amendments. Fine-grained high-Pb minerals were identified using SEM and MP analyses of BT minerals. These minerals were from samples associated with deep-groundwater wells containing Pb at levels greater than regulatory limits. Pb is concentrated in Pb minerals (e.g. cerussite), smectite, and hematite formed during low-T alteration of tuff. Understanding mineralogic speciation of metals may provide insights into sources of groundwater pollution. Tree rings from ponderosa pines that grew in a Ba-contaminated drainage were analyzed using MP. Ba concentrations are typically higher in rings that formed after operations discharging Ba to the environment began. Such tree-ring analyses may ultimately provide information on rates of contaminant migration in the environment. TE in zoned calcites from Yucca Mountain were analyzed by MP. Calcites from the saturated zone (SZ) have distinct chemical signatures (high Fe, Mn and low Y). No calcites in the unsaturated zone with SZ chemical signatures were found using MP. MP analyses of vein minerals can provide insights into mineral sources and hydrogeologic processes. These examples show that TE microanalysis with nuclear microprobes can provide insights into a wide variety of environmental processes. Such information allows more informed, technically defensible negotiations with regulators, saving time and money in environmental cleanup projects. (C) 1997 Elsevier Science B.V. C1 UNIV MANITOBA, DEPT GEOL SCI, WINNIPEG, MB R3T 2N2, CANADA. UNIV NEW MEXICO, DEPT EARTH & PLANETARY SCI, ALBUQUERQUE, NM 87131 USA. RP LOS ALAMOS NATL LAB, EES1, MSD462, LOS ALAMOS, NM 87545 USA. RI Hickmott, Donald/C-2886-2011 NR 44 TC 6 Z9 7 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X EI 1872-9584 J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD JUL PY 1997 VL 130 IS 1-4 BP 564 EP 570 DI 10.1016/S0168-583X(97)00253-X PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XZ017 UT WOS:A1997XZ01700097 ER PT J AU Hickmott, DD Treves, BE Roselle, GT Baumgartner, LP AF Hickmott, DD Treves, BE Roselle, GT Baumgartner, LP TI Micro-PIXE analysis of carbonates and silicates: Tracking fluid flow in crustal environments SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 5th International Conference on Nuclear Microprobe Technology and Applications (ICNMTA) CY NOV 11-15, 1996 CL SANTA FE, NM SP Sandia Natl Labs, Los Alamos Natl Lab, Lawrence Livermore Natl lab ID OCEANIC-CRUST; HYDROTHERMAL ALTERATION; PARTITION-COEFFICIENTS; CALCITE; ISOTOPE; SYSTEMS; OXYGEN; GARNET; RIDGES; RATIOS AB Proton-induced X-ray (PIXE) analyses on a micro-scale of trace-element (TE) variations in metamorphic and hydrothermal minerals can provide insights into fluid-flow processes in lithospheric environments. The Los Alamos nuclear microprobe was used to determine in situ TE abundances in minerals from the Ubehebe Peak contact aureole and from Apennine ophicalcites. In these two crustal environments, known to have experienced significant fluid flow, TE variability in minerals zoning in grains, analyses of multiple mineral generations in single samples, and analyses of grains from spatially-resolved hand-samples provides information on the chemical evolution of fluid-flow systems during geologic processes. (C) 1997 Elsevier Science B.V. C1 UNIV FLORENCE, CNR, CS GEOL APPENNINO, I-50121 FLORENCE, ITALY. UNIV WISCONSIN, DEPT GEOL & GEOPHYS, MADISON, WI 53706 USA. RP Hickmott, DD (reprint author), LOS ALAMOS NATL LAB, EES-1, MS-D462, LOS ALAMOS, NM 87545 USA. RI Hickmott, Donald/C-2886-2011 NR 28 TC 8 Z9 8 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X EI 1872-9584 J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD JUL PY 1997 VL 130 IS 1-4 BP 660 EP 665 DI 10.1016/S0168-583X(97)00262-0 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XZ017 UT WOS:A1997XZ01700111 ER PT J AU Morse, DH Antolak, AJ Bench, GS Heikkinen, DW Roberts, ML SiderasHaddad, E AF Morse, DH Antolak, AJ Bench, GS Heikkinen, DW Roberts, ML SiderasHaddad, E TI Materials analysis at the SNL/LLNL nuclear microprobe SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 5th International Conference on Nuclear Microprobe Technology and Applications (ICNMTA) CY NOV 11-15, 1996 CL SANTA FE, NM SP Sandia Natl Labs, Los Alamos Natl Lab, Lawrence Livermore Natl lab ID LIVERMORE; PACKAGE AB A wide variety of materials have been analyzed using the nuclear microprobe in Livermore, including metals, low density foams, compound semiconductors for room temperature detectors, glasses and particulates. A brief overview of our recent work is given, in addition to a broader discussion of three specific applications. In the first application, Ion Microtomography (IMT) is used to produce three-dimensional mass density maps of low density foams being developed as targets for Z-pinch physics experiments. In the second application, we produce two-dimensional elemental maps of CdZnTe crystals being developed as room temperature radiation detectors. The maps help determine the effect of local variations in stoichiometry on detector performance. Finally, we discuss the measurement of trace elements and radial diffusion profiles in superconducting wire using micro-scale Particle-Induced X-ray Emission (PIXE). C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551. RP Morse, DH (reprint author), SANDIA NATL LABS,BOX 969,MS9402,LIVERMORE,CA 94551, USA. NR 12 TC 7 Z9 7 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD JUL PY 1997 VL 130 IS 1-4 BP 740 EP 745 DI 10.1016/S0168-583X(97)00180-8 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XZ017 UT WOS:A1997XZ01700124 ER PT J AU Aschieri, P AF Aschieri, P TI On the geometry of the quantum Poincare group SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT 30th International Symposium Ahrenshoop on the Theory of Elementary Particles CY AUG 27-31, 1996 CL BUCKOW, GERMANY SP DESY Inst High Energy Phys, Zeuthen, Humboldt Univ, Berlin, Inst Phys, Univ Hannover, Inst Theoret Phys, Univ Munich, Sect Phys, Deut Forschungsgemeinsch, Walter & Eva Andrejewski Fdn, Humboldt Univ, Berlin, IFH DESY, Zeuthen ID DIFFERENTIAL-CALCULUS; ALGEBRAS; GRAVITY AB We review the construction of the multiparametric inhomogeneous orthogonal quantum group ISOq,r(N) as a projection from SOq,r(N + 2), and recall the conjugation that for N = 4 leads to the quantum Poincare group. We study the properties of the universal enveloping algebra U-q,U-r(iso(N)), and give an R-matrix formulation. A quantum Lie algebra and a bicovariant differential calculus on twisted ISO(N) are found. RP Aschieri, P (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV PHYS,THEORET PHYS GRP,1 CYCLOTRON RD,BERKELEY,CA 94720, USA. RI Aschieri, Paolo/J-2965-2012 NR 30 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD JUL PY 1997 SU 56B BP 191 EP 198 DI 10.1016/S0920-5632(97)00326-5 PG 8 WC Physics, Particles & Fields SC Physics GA XM485 UT WOS:A1997XM48500025 ER PT J AU Kornreich, DE Ganapol, BD AF Kornreich, DE Ganapol, BD TI The Green's function method for nuclear engineering applications SO NUCLEAR SCIENCE AND ENGINEERING LA English DT Article ID NEUTRON-TRANSPORT THEORY; FN METHOD AB The Green's function method (GFM) is employed to obtain scalar and angular flux distributions in heterogeneous slab geometry with isotropic scattering. All solutions utilize the infinite-medium Green's function to obtain results in finite media. Past Green's function analyses that do not resort to expansions of the angular flux in basis functions have been performed for nonmultiplying media only; in this paper, results are provided, for the first time, for both multiplying and nonmultiplying media using the GFM. Several source configurations are considered, including a beam source on the leftmost face, isotropic incidence on any face, and constant inhomogeneous volume sources in internal materials. Scalar and angular flux distributions compare favorably with those obtained using the FN method as well as the ONEDANT discrete ordinates code. In addition, the single and heterogeneous critical slab problems are investigated and solved using the GFM. C1 UNIV ARIZONA,DEPT AEROSP & MECH ENGN,TUCSON,AZ 85721. RP Kornreich, DE (reprint author), LOS ALAMOS NATL LAB,TSA-7,MS F609,LOS ALAMOS,NM 87545, USA. NR 31 TC 10 Z9 10 U1 0 U2 0 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 JUL PY 1997 VL 126 IS 3 BP 293 EP 313 PG 21 WC Nuclear Science & Technology SC Nuclear Science & Technology GA XN257 UT WOS:A1997XN25700004 ER PT J AU Greenwood, RC Watts, KD AF Greenwood, RC Watts, KD TI Delayed neutron energy spectra of Br-87, Br-88, Br-89, Br-90, I-137, I-138, I-139, and Te-136 SO NUCLEAR SCIENCE AND ENGINEERING LA English DT Article AB Measurement of the energy spectra of delayed neutrons for the isotope-separated, fission product precursors Br-87, Br-88, Br-89, Br-90, I-137, I-138, I-139, and Te-136 are reported for an energy range up to 1213 keV and with lower cutoff energies of 11.1, 11.1, 29.9, 48.9, 14.2, 23.3, 29.9, and 48.9 keV respectively. These data were obtained at the TRISTAN Isotope Separation On-Line facility using H-2 and CH4 gas-filled proportional counters. The data for each of the bromine, iodine, and tellurium isotopes show good qualitative agreement with the published He-3 ionization chamber delta at energies above similar to 200 keV. In addition, they provide definitive spectral information down to their respective cut-off energies. C1 LOCKHEED IDAHO TECHNOL CO,IDAHO NATL ENGN LAB,IDAHO FALLS,ID 83415. NR 16 TC 10 Z9 10 U1 0 U2 0 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 JUL PY 1997 VL 126 IS 3 BP 324 EP 332 PG 9 WC Nuclear Science & Technology SC Nuclear Science & Technology GA XN257 UT WOS:A1997XN25700006 ER PT J AU Tzanos, CP AF Tzanos, CP TI Impact of wind velocity on the performance of the RVACS decay heat removal system SO NUCLEAR TECHNOLOGY LA English DT Article DE decay heat removal; passive safety systems; wind effects ID AUXILIARY COOLING SYSTEM; REACTOR AB The impact of wind velocity on the performance of the reactor vessel auxiliary cooling system (RVACS) of an advanced liquid-metal reader design is analyzed, and design modifications that mitigate adverse wind effects are investigated. Iri the reference design, the reactor is served by four communicating RVACS stacks, and each stack has two air inlets. In this two-inlet stack design, winds blowing in a direction 90 deg from the axis formed by the two stack inlets result in pressure distributions around the stacks that drastically change the desired airflow pattern in the RVACS. This leads to significantly elevated RVACS air temperatures and significant azimuthal guard vessel temperature variations. For example, a 27 m/s (60 mph) wind leads to an air temperature at the exit of the RVACS heated section that is similar to 115 degrees C higher than that under no-wind conditions. The addition of two more inlets per stack, one inlet per stack side, significantly improves RVACS performance. The air temperature at the exit of the heated RVACS section is significantly reduced below that of the two-inlet design, and this temperature decreases as the wind speed increases. An increase in wind speed from 3 to 27 m/s leads to an air temperature change from 186 to 165 degrees C. The azimuthal temperature variation is also improved. At the top of the guard vessel, this variation is reduced from 62.5 to 8.5 degrees C at the low wind speed of 3 m/s and from 85.0 to 30.5 degrees C at the high wind speed of 27 m/s. RP Tzanos, CP (reprint author), ARGONNE NATL LAB,REACTOR ENGN DIV,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 11 TC 0 Z9 0 U1 0 U2 0 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 SN 0029-5450 J9 NUCL TECHNOL JI Nucl. Technol. PD JUL PY 1997 VL 119 IS 1 BP 1 EP 10 PG 10 WC Nuclear Science & Technology SC Nuclear Science & Technology GA XH310 UT WOS:A1997XH31000001 ER PT J AU Tsoukalas, LH Uhrig, RE AF Tsoukalas, LH Uhrig, RE TI Hypermedia integration of information resources for nuclear plant operations SO NUCLEAR TECHNOLOGY LA English DT Article DE hypermedia; fuzzy sets; nuclear operations ID SYSTEM; RETRIEVAL AB Computer hypermedia technologies offer significant possibilities for integrating data, information, and multifaceted knowledge resources abounding in existing and next-generation nuclear plant operations. A hypermedia system may be viewed as a set of nodes and links allowing nonlinear access to plant information residing in computers regardless of format. The process of accessing information in hypermedia systems is known as navigation. After a review of the state of the art, quantitative criteria are presented for the development of hypermedia databases and a fuzzy graph-based methodology for navigating the large information spaces involved in nuclear plant operations. In the developed methodology, membership functions embodying context-dependent criteria provide application-specific tools for navigation. The methodology is illustrated through numerical examples and a Hyper-Card-based prototypical system for monitoring special material in a next-generation nuclear reactor. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. UNIV TENNESSEE,KNOXVILLE,TN 37996. RP Tsoukalas, LH (reprint author), PURDUE UNIV,SCH NUCL ENGN,W LAFAYETTE,IN 47907, USA. NR 28 TC 1 Z9 1 U1 0 U2 0 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 SN 0029-5450 J9 NUCL TECHNOL JI Nucl. Technol. PD JUL PY 1997 VL 119 IS 1 BP 48 EP 62 PG 15 WC Nuclear Science & Technology SC Nuclear Science & Technology GA XH310 UT WOS:A1997XH31000005 ER PT J AU Reifman, J AF Reifman, J TI Survey of artificial intelligence methods for detection and identification of component faults in nuclear power plants SO NUCLEAR TECHNOLOGY LA English DT Article DE artificial intelligence; nuclear power plants; diagnosis ID NEURAL NETWORKS; EXPERT-SYSTEM; FAILURE DIAGNOSIS; REAL-TIME AB A comprehensive survey of computer-based systems that apply artificial intelligence methods to detect and identify component faults in nuclear power plants is presented. Classification criteria are established that categorize artificial intelligence diagnostic systems according to the types of computing approaches used (e.g., computing tools, computer languages, and shell and simulation programs), the types of methodologies employed (e.g., types of knowledge, reasoning and inference mechanisms, and diagnostic approach), and the scope of the system. The major issues of process diagnostics and computer-based diagnostic systems are identified and cross-correlated with the various categories used for classification. Ninety-five publications are reviewed. RP Reifman, J (reprint author), ARGONNE NATL LAB,REACTOR ANAL DIV,ARGONNE,IL 60439, USA. NR 95 TC 49 Z9 50 U1 0 U2 3 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 SN 0029-5450 J9 NUCL TECHNOL JI Nucl. Technol. PD JUL PY 1997 VL 119 IS 1 BP 76 EP 97 PG 22 WC Nuclear Science & Technology SC Nuclear Science & Technology GA XH310 UT WOS:A1997XH31000007 ER PT J AU Bruck, HA AF Bruck, HA TI The effects of motion on dynamic moire interferometry SO OPTICS AND LASERS IN ENGINEERING LA English DT Article AB Experimental techniques (e.g laser interferometry, photoelasticity) that generate fringe data are currently being utilized for analyzing full-field surface deformations in a variety of dynamic problems in experimental mechanics. As opposed to static problems, the transience of surface deformations in dynamic problems poses a unique problem in accurately resolving the fringe data that is acquired. Neumann determined that for time-lapse, double-exposure holographic interferometry the fringe contrast depends on the data acquisition time, wavelength of the light source, and transience of the dynamic phenomena. Daily performed a similar analysis for dynamic photoelasticity, where the dependence was on the stress gradients instead of the wavelength of the light source. This paper attempts to extend the analysis of Neumann and Daily to the analysis of transient fringe intensity data obtained from using dynamic moire interferometry. It is found that the fringe contrast can depend on the frequency of the fringe field rather than the wavelength of the light source or stress gradients, and the fringe contrast will decay more rapidly for Gaussian light sources than constant intensity light sources. (C) 1997 Elsevier Science Ltd. RP Bruck, HA (reprint author), IDAHO NATL ENGN LAB, POB 1625, MAIL STOP 2218, IDAHO FALLS, ID 83415 USA. NR 13 TC 5 Z9 5 U1 0 U2 2 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0143-8166 J9 OPT LASER ENG JI Opt. Lasers Eng. PD JUL PY 1997 VL 27 IS 4 BP 343 EP 354 DI 10.1016/S0143-8166(96)00044-9 PG 12 WC Optics SC Optics GA WQ926 UT WOS:A1997WQ92600001 ER PT J AU Larsson, J Chang, Z Judd, E Schuck, PJ Falcone, RW Heimann, PA Padmore, HA Kapteyn, HC Bucksbaum, PH Murnane, MM Lee, RW Machacek, A Wark, JS Liu, X Shan, B AF Larsson, J Chang, Z Judd, E Schuck, PJ Falcone, RW Heimann, PA Padmore, HA Kapteyn, HC Bucksbaum, PH Murnane, MM Lee, RW Machacek, A Wark, JS Liu, X Shan, B TI Ultrafast x-ray diffraction using a streak-camera detector in averaging mode SO OPTICS LETTERS LA English DT Article AB We demonstrate an apparatus for measuring time-dependent x-ray diffraction. X-ray pulses from a synchrotron are diffracted by a pair of Si(111) crystals and detected with an x-ray streak camera that has single-shot resolution of better than 1 ps. The streak camera is driven by a photoconductive su itch, which is triggered by 100-fs laser pulses at a repetition rate of 1 kHz. The laser and the streak camera are synchronized with the synchrotron pulses. In the averaging mode, trigger jitter results in 2-ps temporal resolution. We measured the duration of 5-keV pulses from the Advanced Light Source synchrotron to be 70 ps. (C) 1997 Optical Society of America. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,ADV LIGHT SOURCE ACCELERATOR & FUS RES DIV,BERKELEY,CA 94720. UNIV MICHIGAN,CTR ULTRAFAST OPT SCI,ANN ARBOR,MI 48109. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551. UNIV OXFORD,DEPT PHYS,CLARENDON LAB,OXFORD OX1 3PU,ENGLAND. XIAN INST OPT & PRECIS MECH,XIAN 710000,PEOPLES R CHINA. RP Larsson, J (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. RI Chang, Zenghu/K-8143-2012; Kapteyn, Henry/H-6559-2011 OI Chang, Zenghu/0000-0001-9015-0747; Kapteyn, Henry/0000-0001-8386-6317 NR 9 TC 58 Z9 62 U1 2 U2 8 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD JUL 1 PY 1997 VL 22 IS 13 BP 1012 EP 1014 DI 10.1364/OL.22.001012 PG 3 WC Optics SC Optics GA XG253 UT WOS:A1997XG25300024 PM 18185736 ER PT J AU Sinclair, MB Butler, MA Kravitz, SH Zubrzycki, WJ Ricco, AJ AF Sinclair, MB Butler, MA Kravitz, SH Zubrzycki, WJ Ricco, AJ TI Synthetic infrared spectra SO OPTICS LETTERS LA English DT Article ID DIFFRACTIVE OPTICS AB We have designed, microfabricated, and characterized a diffractive optical element that reproduces the infrared spectrum of HF from 3600 to 4300 cm(-1). The reflection-mode diffractive optic consists of 4096 Lines, each 4.5 mu m wide, at 16 discrete depths relative to the substrate from 0 to 1.2 mu m and was fabricated upon a silicon wafer by anisotropic reactive ion-beam etching in a four-mask-level process. We envisage the use of diffractive optical elements of this type as the basis for a new class of miniaturized, remote chemical sensor systems based on correlation spectroscopy. (C) 1997 Optical Society of America. RP Sinclair, MB (reprint author), SANDIA NATL LABS, POB 5800, ALBUQUERQUE, NM 87185 USA. RI Ricco, Antonio/A-5273-2010 NR 9 TC 21 Z9 21 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 JUL 1 PY 1997 VL 22 IS 13 BP 1036 EP 1038 DI 10.1364/OL.22.001036 PG 3 WC Optics SC Optics GA XG253 UT WOS:A1997XG25300032 PM 18185744 ER PT J AU Meffe, GK AF Meffe, GK TI Challenges SO ORYX LA English DT Editorial Material RP Meffe, GK (reprint author), UNIV GEORGIA,SAVANNAH RIVER ECOL LAB,ATHENS,GA 30602, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0NE SN 0030-6053 J9 ORYX JI Oryx PD JUL PY 1997 VL 31 IS 3 BP 155 EP 157 PG 3 WC Ecology SC Environmental Sciences & Ecology GA XJ486 UT WOS:A1997XJ48600003 ER PT J AU Krogh, M Painter, J Hansen, C AF Krogh, M Painter, J Hansen, C TI Parallel sphere rendering SO PARALLEL COMPUTING LA English DT Article; Proceedings Paper CT 1st Eurographics Workshop on Parallel Graphics and Visualisation CY SEP, 1996 CL BRISTOL, ENGLAND DE parallel rendering; sphere rendering; visualization ID DRAW AB Sphere rendering is an important method for visualizing molecular dynamics data. This paper presents a parallel algorithm that is almost 90 times faster than current graphics workstations. To render extremely large data sets and large images, the algorithm uses the MIMD features of the supercomputers to divide up the data, render independent partial images, and then finally composite the multiple partial images using an optimal method. The algorithm and performance results are presented for the CM-5 and the T3D. C1 LOS ALAMOS NATL LAB,ADV COMP LAB,LOS ALAMOS,NM 87545. NR 21 TC 3 Z9 3 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-8191 J9 PARALLEL COMPUT JI Parallel Comput. PD JUL PY 1997 VL 23 IS 7 BP 961 EP 974 DI 10.1016/S0167-8191(97)00038-0 PG 14 WC Computer Science, Theory & Methods SC Computer Science GA XP704 UT WOS:A1997XP70400012 ER PT J AU Li, SP Eastman, JA Vetrone, JM Newnham, RE Cross, LE AF Li, SP Eastman, JA Vetrone, JM Newnham, RE Cross, LE TI Dielectric response in ferroelectric superlattices SO PHILOSOPHICAL MAGAZINE B-PHYSICS OF CONDENSED MATTER STATISTICAL MECHANICS ELECTRONIC OPTICAL AND MAGNETIC PROPERTIES LA English DT Article ID PHASE-TRANSITIONS; SOFT MODES; THIN-FILMS AB The dielectric response of a ferroelectric multilayer, having a designed heterogeneity, has been studied near its phase transition range by use of the Landau-Ginzburg theory. The coherent lattice coupling between ultrathin layers can be significantly strong, resulting in a broad phase transition of the superlattice system as a whole. The thickness of layers and their spatial distribution hold the keys for enhancing dielectric properties in a broad temperature range. C1 PENN STATE UNIV,MAT RES LAB,UNIVERSITY PK,PA 16802. RP Li, SP (reprint author), ARGONNE NATL LAB,DIV MAT SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Eastman, Jeffrey/E-4380-2011; OI Eastman, Jeff/0000-0002-0847-4265 NR 23 TC 33 Z9 33 U1 1 U2 2 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0141-8637 J9 PHILOS MAG B JI Philos. Mag. B-Phys. Condens. Matter Stat. Mech. Electron. Opt. Magn. Prop. PD JUL PY 1997 VL 76 IS 1 BP 47 EP 57 DI 10.1080/01418639708241077 PG 11 WC Materials Science, Multidisciplinary; Mechanics; Physics, Applied; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA XJ781 UT WOS:A1997XJ78100004 ER PT J AU Talbot, MFJ Sauer, K AF Talbot, MFJ Sauer, K TI Spectrofluorimetric method for the determination of large chlorophyll a/b ratios SO PHOTOSYNTHESIS RESEARCH LA English DT Article DE chlorophyll assay; chlorophyll b; chlorophyll extracts; chlorophyll fluorescence ID PROTEIN COMPLEX; PHOTOSYSTEM-I; CAROTENOIDS; SOLVENTS; MUTANTS AB A practical spectrofluorimetric calibration method at room temperature is described for determining large chlorophyll a/b ratios on direct extracts from plant material of pigments in 80% aqueous acetone, dimethyl sulfoxide, and N,N'-dimethylformamide. The method is based on the work of Boardman and Thorne [Boardman NK and Thorne SW (1971)Biochim Biophys Acta 253: 222-231] who used diethyl ether as solvent. We repeated the calibration in diethyl ether and find significantly different parameters for the calibration curve. The range of standards in this work included solutions with chlorophyll a/b ratios of 10-125 in dimethyl sulfoxide, and of 10-220 in the other solvents. Fluorescence emission spectra were found to be a highly sensitive method for assessing chlorophyll purity. We determined the limits of sensitivity for each solvent from the calibration data. The empirically determined slope of the calibration curve was shown to be related to intrinsic properties of the chlorophylls in solution; this allows predictions of the performance of the method in other solvents. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,STRUCT BIOL DIV,BERKELEY,CA 94720. RP Talbot, MFJ (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DEPT CHEM,BERKELEY,CA 94720, USA. NR 19 TC 5 Z9 6 U1 2 U2 11 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0166-8595 J9 PHOTOSYNTH RES JI Photosynth. Res. PD JUL PY 1997 VL 53 IS 1 BP 73 EP 79 DI 10.1023/A:1005809801266 PG 7 WC Plant Sciences SC Plant Sciences GA YD408 UT WOS:A1997YD40800009 ER PT J AU Behrenfeld, MJ AF Behrenfeld, Michael J. TI UV impacts on marine algae SO PHYCOLOGIA LA English DT Meeting Abstract C1 [Behrenfeld, Michael J.] Brookhaven Natl Lab, Div Oceanog & Atmospher Sci, Upton, NY 11973 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU INT PHYCOLOGICAL SOC PI LAWRENCE PA NEW BUSINESS OFFICE, PO BOX 1897, LAWRENCE, KS 66044-8897 USA SN 0031-8884 J9 PHYCOLOGIA JI Phycologia PD JUL PY 1997 VL 36 IS 4 SU S MA 24 BP 7 EP 7 PG 1 WC Plant Sciences; Marine & Freshwater Biology SC Plant Sciences; Marine & Freshwater Biology GA V43TS UT WOS:000202958000025 ER PT J AU Partensky, F van der Staay, GWM Garczarek, L Falkowski, P LaRoche, J AF Partensky, F. van der Staay, G. W. M. Garczarek, L. Falkowski, P. LaRoche, J. TI Characterization of chlorophyll A/B-protein complexes of Prochlorococcus suggests an original organization of its photosynthetic apparatus SO PHYCOLOGIA LA English DT Meeting Abstract C1 [Partensky, F.; van der Staay, G. W. M.; Garczarek, L.] Univ Paris 06, CNRS, Biol Stn, F-29682 Roscoff, France. [Falkowski, P.; LaRoche, J.] Brookhaven Natl Lab, Environm Biophys & Mol Biol Program, Upton, NY USA. RI LaRoche, Julie/A-1109-2010 NR 0 TC 0 Z9 0 U1 0 U2 0 PU INT PHYCOLOGICAL SOC PI LAWRENCE PA NEW BUSINESS OFFICE, PO BOX 1897, LAWRENCE, KS 66044-8897 USA SN 0031-8884 J9 PHYCOLOGIA JI Phycologia PD JUL PY 1997 VL 36 IS 4 SU S MA 317 BP 83 EP 83 PG 1 WC Plant Sciences; Marine & Freshwater Biology SC Plant Sciences; Marine & Freshwater Biology GA V43TS UT WOS:000202958000318 ER PT J AU Fuchs, R Mendoza, CI Barrera, RG Carrillo, JL AF Fuchs, R Mendoza, CI Barrera, RG Carrillo, JL TI Electron energy-loss spectroscopy of inhomogeneous systems SO PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS LA English DT Article; Proceedings Paper CT 4th International Conference on Electrical Transport and Optical Properties of Inhomogeneous Media (ETOPIM4) CY JUL 23-30, 1996 CL ST PETERSBURG, RUSSIA DE disordered systems; electron energy-loss spectroscopy; effective dielectric function; spectral representation; spherical inclusions; surface response function ID EXCITATION; SURFACES AB After beginning with a brief review of the theory of electron energy loss by an unbounded random system of spherical inclusions characterized by a local dielectric function, we examine several extensions of this theory. We first treat an inhomogeneous system of spherical particles confined to a half-space. A surface response function, which can be used to calculate the energy-loss spectrum for charged particles moving outside the system, is defined, and this response function is written in a spectral representation. We discuss different approaches to this problem: the semiclassical infinite barrier model, an exact formal theory, and a continuous effective medium theory. Finally, we develop a theory of electron energy loss for a mixture of two components with arbitrary geometry, unbounded in three dimensions. C1 IOWA STATE UNIV SCI & TECHNOL, DEPT PHYS & ASTRON, AMES, IA 50011 USA. UNIV NACL AUTONOMA MEXICO, INST FIS, MEXICO CITY 01000, DF, MEXICO. UNIV AUTONOMA PUEBLA, INST FIS LUIS RIVERA TERRAZAS, PUEBLA 72570, MEXICO. RP Fuchs, R (reprint author), IOWA STATE UNIV SCI & TECHNOL, AMES LAB, AMES, IA 50011 USA. NR 11 TC 7 Z9 7 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-4371 EI 1873-2119 J9 PHYSICA A JI Physica A PD JUL 1 PY 1997 VL 241 IS 1-2 BP 29 EP 44 DI 10.1016/S0378-4371(97)00056-3 PG 16 WC Physics, Multidisciplinary SC Physics GA XL610 UT WOS:A1997XL61000006 ER PT J AU Aeppli, G Broholm, C DiTusa, JF Hayden, SM Ito, T Lee, SH Mason, TE Mook, HA Oka, K Perring, TG Schroder, A Takagi, H Xu, G AF Aeppli, G Broholm, C DiTusa, JF Hayden, SM Ito, T Lee, SH Mason, TE Mook, HA Oka, K Perring, TG Schroder, A Takagi, H Xu, G TI Magnetic coherence in the transition metal oxides SO PHYSICA B LA English DT Article; Proceedings Paper CT 5th International Conference / 45th Yamada Conference on Physics of Transition Metals (ICPTM 96) CY SEP 24-27, 1996 CL OSAKA, JAPAN SP Yamada Sci Fdn DE Kagome lattice; spin liquid; transition metal oxide ID SUPERCONDUCTING LA1.85SR0.15CUO4; NEUTRON-SCATTERING; SPIN FLUCTUATIONS; KAGOME LATTICE; HALDANE-GAP; EXCITATIONS; DYNAMICS; YBA2CU3O6+X; CHAIN; LA1.86SR0.14CUO4 AB We review neutron scattering experiments which address the coherence of the ground states of four transition metal oxides. The states considered include some which, at the qualitative level, can be described classically and others which require a quantum mechanical understanding. In the former category are the antiferromagnetism of YBa2Cu3O6.15, and the peculiar ground stale of the Kagome compound SrCr9pGa12-9pO19, which is neither an antiferromagnet nor a spin glass. The latter category contains the Haldane quantum spin liquid, seen very clearly in the linear-chain compound Y2BaNiO5, and the superconducting slate of La1.86Sr0.14CuO4. C1 JOHNS HOPKINS UNIV,DEPT PHYS & ASTRON,BALTIMORE,MD 21218. LOUISIANA STATE UNIV,DEPT PHYS & ASTRON,BATON ROUGE,LA 70803. UNIV BRISTOL,HH WILLS PHYS LAB,BRISTOL BS8 1TL,AVON,ENGLAND. ELECTROTECH LAB,TSUKUBA,IBARAKI 305,JAPAN. OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. UNIV TORONTO,DEPT PHYS,TORONTO,ON M5S 1A7,CANADA. RUTHERFORD APPLETON LAB,ISIS FACIL,DIDCOT OX11 0QX,OXON,ENGLAND. RISO NATL LAB,DEPT SOLID STATE PHYS,DK-4000 ROSKILDE,DENMARK. UNIV TOKYO,ISSP,TOKYO 106,JAPAN. NIST,GAITHERSBURG,MD 20899. RP Aeppli, G (reprint author), NEC RES INST,4 INDEPENDENCE WAY,PRINCETON,NJ 08540, USA. RI Broholm, Collin/E-8228-2011; Hayden, Stephen/F-4162-2011; Xu, Guangyong/A-8707-2010; Takagi, Hidenori/B-2935-2010; Mason, Thomas/M-5809-2014 OI Broholm, Collin/0000-0002-1569-9892; Hayden, Stephen/0000-0002-3209-027X; Xu, Guangyong/0000-0003-1441-8275; Mason, Thomas/0000-0003-1880-3971 NR 28 TC 0 Z9 0 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD JUL PY 1997 VL 237 BP 30 EP 35 DI 10.1016/S0921-4526(97)00035-5 PG 6 WC Physics, Condensed Matter SC Physics GA XM233 UT WOS:A1997XM23300013 ER PT J AU Hirota, K Kaneko, N Nishizawa, A Endoh, Y Martin, MC Shirane, G AF Hirota, K Kaneko, N Nishizawa, A Endoh, Y Martin, MC Shirane, G TI Neutron-scattering studies of magnetic excitations in La1-xSrxMnO3: A dimensional crossover SO PHYSICA B LA English DT Article; Proceedings Paper CT 5th International Conference / 45th Yamada Conference on Physics of Transition Metals (ICPTM 96) CY SEP 24-27, 1996 CL OSAKA, JAPAN SP Yamada Sci Fdn DE magnetoresistance; spin waves; La1-xSrxMnO3 AB We have found a strong planar ferromagnetic and a weak antiferromagnetic interplane couplings in the spin waves of LaMnO3. Upon doping holes, the anisotropic character initially becomes enhanced. However, it is taken over by the isotropic ferromagnetic spin waves when the Sr concentration x reaches similar to 0.1, much lower than the compositional metal-insulator transition range (x similar to 0.17). C1 BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. RP Hirota, K (reprint author), TOHOKU UNIV,DEPT PHYS,SENDAI,MIYAGI 98077,JAPAN. RI Hirota, Kazuma/C-6797-2008 NR 5 TC 25 Z9 25 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 JUL PY 1997 VL 237 BP 36 EP 38 DI 10.1016/S0921-4526(97)00039-2 PG 3 WC Physics, Condensed Matter SC Physics GA XM233 UT WOS:A1997XM23300014 ER PT J AU Birgeneau, RJ Christianson, RJ Endoh, Y Kastner, MA Lee, YS Shirane, G Wells, BO Yamada, K AF Birgeneau, RJ Christianson, RJ Endoh, Y Kastner, MA Lee, YS Shirane, G Wells, BO Yamada, K TI Structures and incommensurate spin excitations in excess oxygen-doped La2CuO4+y SO PHYSICA B LA English DT Article; Proceedings Paper CT 5th International Conference / 45th Yamada Conference on Physics of Transition Metals (ICPTM 96) CY SEP 24-27, 1996 CL OSAKA, JAPAN SP Yamada Sci Fdn DE superconductivity; magnetism; staging; high-temperature ID SUPERCONDUCTING LA1.85SR0.15CUO4; NEUTRON-SCATTERING; FLUCTUATIONS; LA2-XSRXCUO4 AB Over the past decade, we have studied in detail the low-energy spin fluctuations in La2-xSrxCuO4 for x between 0 and 0.18. Our experiments, as well as those by others, have revealed a fascinating interplay between the hole doping, the static and dynamic spin fluctuations and superconductivity. Recently, using electrochemical techniques, we have learned how to produce large single crystals of La2CuO4+y which are relatively homogenous. In this latter system, the dopants are characterized by annealed rather than quenched disorder. Furthermore, we have demonstrated staging behavior of the excess oxygen analogous to staging in intercalated graphite. We have now succeeded in carrying out measurements of the low-energy spin fluctuations in stage-6 La2CuO4+y. Specifically, we find that in this system which has T-c = 31 K, the spin fluctuations are incommensurate with energy and temperature dependencies very much like those in La1.85Sr0.15CuO4 with T-c = 33 K. In addition, we find that T-c/delta is a constant for high-quality materials in both La2-xSrxCuO4 and La2CuO4+y, here delta Is the incommensurability. C1 TOHOKU UNIV,DEPT PHYS,SENDAI,MIYAGI 98077,JAPAN. BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. RP Birgeneau, RJ (reprint author), MIT,DEPT PHYS,CAMBRIDGE,MA 02139, USA. RI Yamada, Kazuyoshi/C-2728-2009 NR 23 TC 2 Z9 2 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD JUL PY 1997 VL 237 BP 84 EP 90 DI 10.1016/S0921-4526(97)00058-6 PG 7 WC Physics, Condensed Matter SC Physics GA XM233 UT WOS:A1997XM23300033 ER PT J AU Tohyama, T Mizuno, Y Maekawa, S Kim, C Shen, ZX AF Tohyama, T Mizuno, Y Maekawa, S Kim, C Shen, ZX TI Electronic states and effective Hamiltonian of CuGeO3 SO PHYSICA B LA English DT Article; Proceedings Paper CT 5th International Conference / 45th Yamada Conference on Physics of Transition Metals (ICPTM 96) CY SEP 24-27, 1996 CL OSAKA, JAPAN SP Yamada Sci Fdn DE CuGeO3; charge-transfer gap; superexchange interaction; optical transmission spectra ID SPIN-PEIERLS TRANSITION AB The electronic states of CuGeO3 are investigated by the ionic and cluster model approaches. The charge transfer gap is found to be more than 3 eV. A 't-J'-like effective Hamiltonian is derived from examining the superexchange interactions between coppers and the hopping energies of the Zhang-Rice singlet. The results of the optical transmission measurements are presented. We find good agreement between the theory and the experiment. C1 NAGOYA UNIV,DEPT APPL PHYS,NAGOYA,AICHI 46401,JAPAN. TOHOKU UNIV,INST MAT RES,SENDAI,MIYAGI 98077,JAPAN. STANFORD UNIV,DEPT APPL PHYS,STANFORD,CA 94305. STANFORD UNIV,STANFORD SYNCHROTRON RADIAT LAB,STANFORD,CA 94305. RP Tohyama, T (reprint author), MIE UNIV,FAC EDUC,DEPT PHYS,TSU,MIE 514,JAPAN. NR 9 TC 2 Z9 2 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 JUL PY 1997 VL 237 BP 135 EP 136 DI 10.1016/S0921-4526(97)00074-4 PG 2 WC Physics, Condensed Matter SC Physics GA XM233 UT WOS:A1997XM23300049 ER PT J AU Uwatoko, Y Ishii, T Oomi, G Takahashi, H Mori, N Nimori, S Kido, G Sarrao, JL Mandrus, D Fisk, Z Thompson, JD AF Uwatoko, Y Ishii, T Oomi, G Takahashi, H Mori, N Nimori, S Kido, G Sarrao, JL Mandrus, D Fisk, Z Thompson, JD TI Effect of pressure on the electrical resistivity and magnetization of CeScGe SO PHYSICA B LA English DT Article; Proceedings Paper CT 5th International Conference / 45th Yamada Conference on Physics of Transition Metals (ICPTM 96) CY SEP 24-27, 1996 CL OSAKA, JAPAN SP Yamada Sci Fdn DE CeScGe; pressure effect; magnetization; electrical resistivity AB Measurement of the magnetization up to H = 30 T at 4.2 K, temperature dependence of magnetic susceptibility and effect of pressure on the electrical resistivity on CeScGe are presented. These results indicate that CeScGe is antiferromagnetic with T-N = 46 K. The Neel temperature T-N decreases with increasing pressure with the rate of dT(N)/dP = -0.56 K/kbar. C1 KUMAMOTO UNIV,FAC ENGN,KUMAMOTO 860,JAPAN. UNIV TOKYO,INST SOLID STATE PHYS,TOKYO 106,JAPAN. NATL RES INST MET,TML,TSUKUBA,IBARAKI 305,JAPAN. FLORIDA STATE UNIV,TALLAHASSEE,FL 32306. NATL HIGH MAGNET FIELD LAB,TALLAHASSEE,FL 32306. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP Uwatoko, Y (reprint author), SAITAMA UNIV,FAC SCI,DEPT PHYS,URAWA,SAITAMA 338,JAPAN. RI Nimori, Shigeki/H-2643-2011; Mandrus, David/H-3090-2014 NR 5 TC 13 Z9 13 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD JUL PY 1997 VL 237 BP 207 EP 209 PG 3 WC Physics, Condensed Matter SC Physics GA XM233 UT WOS:A1997XM23300074 ER PT J AU Kawanaka, H Nakotte, H Bruck, E Prokes, K KimNgan, NH Takabatake, T Fujii, H Sakurai, J AF Kawanaka, H Nakotte, H Bruck, E Prokes, K KimNgan, NH Takabatake, T Fujii, H Sakurai, J TI Thermal properties of UPdSn and UCuSn SO PHYSICA B LA English DT Article; Proceedings Paper CT 5th International Conference / 45th Yamada Conference on Physics of Transition Metals (ICPTM 96) CY SEP 24-27, 1996 CL OSAKA, JAPAN SP Yamada Sci Fdn DE specific heat; thermoelectric power; UPdSn; UCuSn; 5f-electron AB We report on the specific heat and the thermopower of UPdSn and UCuSn, both of which order antiferromagnetically at low temperatures. The compounds show similar behaviour in the specific heat, and the large magnetic-entropy changes around T-N are evidence for a large degree of 5f-electron localization. For both compounds, we find that thermopower results are consistent with the findings for the electrical resistance. While for UCuSn very abrupt changes at 25 and 60 K are observed for both quantities, more continuous changes at the magnetic transitions (25 and 40 K) are found for UPdSn. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. UNIV AMSTERDAM,NL-1018 XE AMSTERDAM,NETHERLANDS. HIROSHIMA UNIV,HIGASHIHIROSHIMA 739,JAPAN. TOYAMA UNIV,TOYAMA 930,JAPAN. RP Kawanaka, H (reprint author), ELECTROTECH LAB,1-1-4 UMEZONO,TSUKUBA,IBARAKI 305,JAPAN. RI Bruck, Ekkes/E-3365-2014; Takabatake, Toshiro/L-2882-2014 OI Takabatake, Toshiro/0000-0002-3293-8592 NR 9 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD JUL PY 1997 VL 237 BP 226 EP 228 DI 10.1016/S0921-4526(97)00111-7 PG 3 WC Physics, Condensed Matter SC Physics GA XM233 UT WOS:A1997XM23300081 ER PT J AU Fullerton, EE Bader, SD Robertson, JL AF Fullerton, EE Bader, SD Robertson, JL TI Spin-density-wave antiferromagnetism of Cr in Fe/Cr(001) superlattices SO PHYSICA B LA English DT Article; Proceedings Paper CT 5th International Conference / 45th Yamada Conference on Physics of Transition Metals (ICPTM 96) CY SEP 24-27, 1996 CL OSAKA, JAPAN SP Yamada Sci Fdn DE Fe/Cr superlattices; antiferromagnetism; spin density waves; neutron scattering; multilayers ID MAGNETORESISTANCE; CHROMIUM; FILMS AB The antiferromagnetic spin-density-wave (SDW) order of Cr layers in Fe/Cr(0 0 1) superlattices was investigated by neutron scattering. For Cr thicknesses from 51 to 190 Angstrom, a transverse SDW is formed for all temperatures below the Neel temperature with a single wave vector Q normal to the layers. A coherent magnetic structure forms with the nodes of the SDW near the Fe-Cr interfaces. For thinner Cr layers, the magnetic scattering can be described by commensurate antiferromagnetic order. C1 OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. RP Fullerton, EE (reprint author), ARGONNE NATL LAB,DIV MAT SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Bader, Samuel/A-2995-2013; Fullerton, Eric/H-8445-2013 OI Fullerton, Eric/0000-0002-4725-9509 NR 14 TC 1 Z9 1 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD JUL PY 1997 VL 237 BP 234 EP 238 DI 10.1016/S0921-4526(97)00115-4 PG 5 WC Physics, Condensed Matter SC Physics GA XM233 UT WOS:A1997XM23300084 ER PT J AU Ishii, T Oomi, G Uwatoko, Y Canfield, PC Cho, BK AF Ishii, T Oomi, G Uwatoko, Y Canfield, PC Cho, BK TI Magnetoresistance of ErNi2B2C under high pressure SO PHYSICA B LA English DT Article; Proceedings Paper CT 5th International Conference / 45th Yamada Conference on Physics of Transition Metals (ICPTM 96) CY SEP 24-27, 1996 CL OSAKA, JAPAN SP Yamada Sci Fdn DE ErNi2B2C; magnetoresistance; high pressure; borocarbide ID SUPERCONDUCTIVITY; MAGNETISM AB The transverse magnetoresistance (MR) of ErNi2B2C at 4.2K has been measured in the field direction parallel and perpendicular to the c-axis (H parallel to c and H perpendicular to c) under high pressure up to 2.2 GPa. It is found that the upper critical field H-c2 is anisotropic and decreases with increasing pressure having a rate of dH(c2)/dP = -0.02 T/GPa and -0.01 T/GPa for H parallel to c and H perpendicular to c, respectively. For H perpendicular to c, metamagnetic transition occurs at H' = 2T and H' increase with pressure with +0.1T/GPa. C1 KUMAMOTO UNIV,DEPT MECH ENGN & MAT SCI,KUMAMOTO 860,JAPAN. KUMAMOTO UNIV,GRAD SCH SCI & TECHNOL,KUMAMOTO 860,JAPAN. SAITAMA UNIV,DEPT PHYS,URAWA,SAITAMA 338,JAPAN. IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS & ASTRON,AMES,IA 50011. RI Canfield, Paul/H-2698-2014 NR 7 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD JUL PY 1997 VL 237 BP 299 EP 301 DI 10.1016/S0921-4526(97)00180-4 PG 3 WC Physics, Condensed Matter SC Physics GA XM233 UT WOS:A1997XM23300104 ER PT J AU Antropov, VP Katsnelson, MI Liechtenstein, AI AF Antropov, VP Katsnelson, MI Liechtenstein, AI TI Exchange interactions in magnets SO PHYSICA B LA English DT Article; Proceedings Paper CT 5th International Conference / 45th Yamada Conference on Physics of Transition Metals (ICPTM 96) CY SEP 24-27, 1996 CL OSAKA, JAPAN SP Yamada Sci Fdn DE density functional; exchange interaction ID IRON AB We present results of a general approach for the calculation of different magnetic interaction parameters for arbitrary systems of magnetic moments. The method is implemented within the density functional approach and some illustrative examples are presented to demonstrate the flexibility and usefulness of the proposed method. RP Antropov, VP (reprint author), IOWA STATE UNIV,DEPT PHYS & ASTRON,AMES LAB,AMES,IA 50011, USA. RI Katsnelson, Mikhail/D-4359-2012; Lichtenstein, Alexander/K-8730-2012 OI Lichtenstein, Alexander/0000-0003-0152-7122 NR 8 TC 25 Z9 25 U1 0 U2 10 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD JUL PY 1997 VL 237 BP 336 EP 340 DI 10.1016/S0921-4526(97)00203-2 PG 5 WC Physics, Condensed Matter SC Physics GA XM233 UT WOS:A1997XM23300116 ER PT J AU Yokoya, T Chainani, A Takahashi, T Ding, H Campuzano, JC Kasai, M Tokura, Y AF Yokoya, T Chainani, A Takahashi, T Ding, H Campuzano, JC Kasai, M Tokura, Y TI Angle-resolved photoemission spectroscopy of non-cuprate two-dimensional perovskite superconductor Sr2RuO4 SO PHYSICA B LA English DT Article; Proceedings Paper CT 5th International Conference / 45th Yamada Conference on Physics of Transition Metals (ICPTM 96) CY SEP 24-27, 1996 CL OSAKA, JAPAN SP Yamada Sci Fdn DE angle-resolved photoemission spectroscopy; Sr2RuO4; extended van Hove singularity; Fermi surface topology ID SINGULARITY AB We have performed high-resolution angle-resolved photoemission spectroscopy on single crystal Sr2RuO4 at low temperature. We observed that the dispersion of energy bands near the Fermi level (E-F) is about two times smaller than the band calculation. One band forms an extended van-Hove singularity (vHs) near E-F around the midpoint between Gamma and Z point like in cuprate superconductors, regardless of the character of electronic states near E-F. The observed Fermi surface topology (one electron-like Fermi surface sheet centered at Gamma point and two hole-like ones centered at X point) is qualitatively different from the calculated Fermi surface topology (two electron-like fermi sheets centered at Gamma point and one hole-like one centered at X point), though the observed total electron count seems to be conserved, These results suggest that the extended vHs may be a general electronic structure of correlated two-dimensional metals and the correlation effect may change the Fermi surface topology as well as the band dispersion. C1 UNIV ILLINOIS,DEPT PHYS,CHICAGO,IL 60607. ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. JOINT RES CTR ATOM TECHNOL,TSUKUBA,IBARAKI 305,JAPAN. UNIV TOKYO,DEPT APPL PHYS,TOKYO 113,JAPAN. RP Yokoya, T (reprint author), TOHOKU UNIV,DEPT PHYS,SENDAI,MIYAGI 98077,JAPAN. RI Chainani, Ashish/B-3071-2011; Tohoku, Arpes/A-4890-2010; Takahashi, Takashi/E-5080-2010; Campuzano, Juan Carlos/G-4358-2012; Tokura, Yoshinori/C-7352-2009; YOKOYA, Takayoshi/B-1478-2011 OI Chainani, Ashish/0000-0002-5639-5393; Ding, Hong/0000-0003-4422-9248; NR 8 TC 0 Z9 0 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD JUL PY 1997 VL 237 BP 377 EP 379 DI 10.1016/S0921-4526(97)00237-8 PG 3 WC Physics, Condensed Matter SC Physics GA XM233 UT WOS:A1997XM23300131 ER PT J AU Fishman, RS Viswanath, VS Liu, SH AF Fishman, RS Viswanath, VS Liu, SH TI Spin and charge dynamics of chromium alloys SO PHYSICA B LA English DT Article; Proceedings Paper CT 5th International Conference / 45th Yamada Conference on Physics of Transition Metals (ICPTM 96) CY SEP 24-27, 1996 CL OSAKA, JAPAN SP Yamada Sci Fdn DE spin density wave; charge density wave; spin waves; phasons; Cr alloys ID MAGNETIC EXCITATIONS; WAVE AB Both the spin- and charge-density waves of Cr alloys are produced by the Coulomb attraction between electrons and holes on nearly nested Fermi surfaces. Driven by quasiparticle transitions, transverse spin-wave and longitudinal phason modes are associated with the rotational and translational symmetries of pure Cr and its dilute alloys. At low frequencies, both spin and charge phasons have a nearly linear dispersion with a mode velocity which approaches the spin-wave velocity as T approaches T-N or as the mismatch between the Fermi surfaces increases. C1 UNIV CALIF SAN DIEGO,DEPT PHYS,LA JOLLA,CA 92093. RP Fishman, RS (reprint author), OAK RIDGE NATL LAB,DIV SOLID STATE,POB 2008,OAK RIDGE,TN 37831, USA. RI Fishman, Randy/C-8639-2013 NR 16 TC 0 Z9 0 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 JUL PY 1997 VL 237 BP 432 EP 435 DI 10.1016/S0921-4526(97)00118-X PG 4 WC Physics, Condensed Matter SC Physics GA XM233 UT WOS:A1997XM23300150 ER PT J AU Kessler, DA Kupferman, R AF Kessler, DA Kupferman, R TI Spirals in excitable media .2. Meandering transition in the diffusive free-boundary limit SO PHYSICA D LA English DT Article ID CARDIAC TISSUE; CYCLIC-AMP; WAVES; MODEL; DYNAMICS; CORE; EQUATIONS AB In this paper we present a numerical stability calculation for steadily rotating spirals in an excitable medium. While experiments, as well as numerical simulations of two-field reaction-diffusion models have shown the existence of a Hopf bifurcation from steady rotations to a meandering state, all the analytical approaches so far have failed to predict this transition. This mismatch between analysis and simulations raises the question whether meandering critically depends on the finite diffusivity of the interface separating between the excited and the refractory phases. Our calculations show that this is not the case. The meandering transition takes place even in the limit of an infinitely sharp interface. The boundaries of the meandering transition as function of the model parameters are traced. We discuss possible explanations fbr the failure of previous analytical approaches. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. BAR ILAN UNIV,MINERVA CTR,IL-52900 RAMAT GAN,ISRAEL. BAR ILAN UNIV,DEPT PHYS,IL-52900 RAMAT GAN,ISRAEL. RI Kessler, David/B-1391-2008 OI Kessler, David/0000-0002-5279-1655 NR 31 TC 7 Z9 7 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 JUL 1 PY 1997 VL 105 IS 4 BP 207 EP 225 DI 10.1016/S0167-2789(96)00298-9 PG 19 WC Mathematics, Applied; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA XJ505 UT WOS:A1997XJ50500001 ER PT J AU Bliek, FW Hoekstra, R Bannister, ME Havener, CC AF Bliek, FW Hoekstra, R Bannister, ME Havener, CC TI Low-energy electron capture by C4+ ions from atomic hydrogen SO PHYSICAL REVIEW A LA English DT Article ID MULTIPLY-CHARGED ION; SLOW COLLISIONS; CROSS-SECTIONS; MERGED-BEAMS; H-ATOMS; H-2; C-4+ AB The total-electron-capture cross section for collisions of C4+ with ground-state hydrogen (deuterium) is measured in the energy range 6-1000 eV/u using the merged-beam technique. The fraction of C4+ metastable ions present in the ion beam is measured to be 5%, which results in a correction to the cross section of only a few percent. The independently absolute measurements are generally in good agreement with previous measurements for total electron capture; however, the reduced uncertainties of these measurements allow a more detailed comparison with theory. Our observations show that existing fully quantal molecular-orbital calculations that include rotational coupling overestimate the cross section by approximately 25%. Better agreement is found with a recent semiclassical impact-parameter coupled-channel calculation. While all available theoretical data predict that the cross section varies smoothly with energy around the maximum, a sharp structure is observed around 400 eV/u. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP Bliek, FW (reprint author), UNIV GRONINGEN,KVI,ZERNIKELAAN 25,NL-9747 AA GRONINGEN,NETHERLANDS. RI Hoekstra, Ronnie/E-9279-2012; OI Bannister, Mark E./0000-0002-9572-8154 NR 36 TC 30 Z9 30 U1 0 U2 0 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 JUL PY 1997 VL 56 IS 1 BP 426 EP 431 DI 10.1103/PhysRevA.56.426 PG 6 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA XL645 UT WOS:A1997XL64500051 ER PT J AU McGuire, EJ AF McGuire, EJ TI Ion-atom inelastic scattering cross sections and energy loss in the plane-wave Born approximation SO PHYSICAL REVIEW A LA English DT Article ID STOPPING POWERS AB A procedure discussed by Bates for calculating ion-atom excitation and ionization cross sections and energy loss in the plane-wave Born approximation has been programmed. The procedure involves integration over the product of elastic scattering factors or generalized oscillator strengths for excitation or ionization from both projectile and target, The calculations are done in the center-of-mass system where the distinction between projectile and target is lost. Thus the cross sections and energy loss in the laboratory frames of both target and projectile emerge from a center-of-mass calculation symmetrical in nuclear and net charges. The traditional simple modeling of energy loss, using scaled proton stopping power (SP) and an effective projectile charge, is unsymmetrical, and therefore dubious as a guide for extrapolating to ion-ion energy loss. Because the energy loss includes processes that cannot be uniquely allocated to one ion or the other, e.g., mutual ionization, one does not expect, in general, a simple SP picture to suffice. However, it is found at intermediate and high center-of-mass energies that the energy loss is dominated by elastic scattering of one ion and ionization of the other. From this observation, and the requirement that hydrogenic ion results be recovered in the appropriate limit, a simple extension of the Bethe formula is obtained. Explicit subshell and total ionization cross sections are presented for Li ions interacting with neutral Zn and Au, and the calculated energy loss is compared with experiment. It is found that the simple extension of the Bethe formula is in surprisingly good agreement with the explicit calculations, suggesting that an improved extension of the Bethe formula may exist. RP McGuire, EJ (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 18 TC 8 Z9 8 U1 0 U2 0 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 JUL PY 1997 VL 56 IS 1 BP 488 EP 500 DI 10.1103/PhysRevA.56.488 PG 13 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA XL645 UT WOS:A1997XL64500058 ER PT J AU Farhat, A Humphrey, M Langer, B Berrah, N Bozek, JD Cubaynes, D AF Farhat, A Humphrey, M Langer, B Berrah, N Bozek, JD Cubaynes, D TI Angle-resolved study of Ar 2p(1/2,3/2)(1-)ns,d resonant Auger decay SO PHYSICAL REVIEW A LA English DT Article ID ANGULAR-DISTRIBUTION; SHAKE-OFF; ELECTRONS; XE; AUTOIONIZATION; SPECTRA; ARGON; KR; TRANSITIONS; EXCITATION AB Angle-resolved measurements of the Ar 2p(1/2)(-1)4s,3d,4d and 2p(3/2)(-1)4s,3d,4d resonant Auger transitions have been carried out using photons from an undulator beamline at the Advanced Light Source. The intensity distributions and angular distribution anisotropy (beta) parameters have been reported for nearly all of the possible 3p(4)nl final ionic states. Our results further verify the predictions of the spectator model for the 2p(1/2,3/2)(-1)4s resonances and the subsequent breakdown of this model for the 2p(1/2,3/2)(-1)3d and 2p(1/2,3/2)(-1)4d relative intensities. No prior measurement of the resonant Auger beta parameters of the 2p(1/2,3/2)(-1)3d and 2p(1/2,3/2)(-1)4d resonances, and the intensity distribution for the 2p(1/2)(-1)4d resonance has been reported, to the best of our knowledge. Our results have been compared with previous experimental and theoretical results wherever possible. C1 LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. UNIV PARIS 11,URA 775 CNRS,LAB SPECT ATOM & ION,F-91405 ORSAY,FRANCE. RP Farhat, A (reprint author), WESTERN MICHIGAN UNIV,DEPT PHYS,KALAMAZOO,MI 49008, USA. RI Bozek, John/E-4689-2010; Langer, Burkhard/A-6504-2013; Bozek, John/E-9260-2010 OI Bozek, John/0000-0001-7486-7238 NR 29 TC 13 Z9 13 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 JUL PY 1997 VL 56 IS 1 BP 501 EP 513 DI 10.1103/PhysRevA.56.501 PG 13 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA XL645 UT WOS:A1997XL64500059 ER PT J AU Hino, K Igarashi, A Macek, JH AF Hino, K Igarashi, A Macek, JH TI Criteria for the validity of the diabatic-by-sector expansion in the hyperspherical coordinate method SO PHYSICAL REVIEW A LA English DT Article AB It is mathematically indicated that the widely used diabatic-by-sector recipe for solving coupled radial equations in the hyperspherical coordinate method causes non-negligible errors and these are revealed especially for extremely low-energy scattering. The intrinsic defects due to this method are illustrated for both bound state and the scattering states of dt mu. The calculated results are also compared with those obtained by the adiabatic expansion method. C1 RIKEN,INST PHYS & CHEM RES,ATOM PHYS LAB,WAKO,SAITAMA 35101,JAPAN. UNIV TENNESSEE,DEPT PHYS & ASTRON,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP Hino, K (reprint author), UNIV ELECTROCOMMUN,DEPT APPL PHYS & CHEM,1-5-1 CHOFUGAOKA,CHOFU,TOKYO 182,JAPAN. NR 10 TC 9 Z9 9 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 JUL PY 1997 VL 56 IS 1 BP 1038 EP 1041 DI 10.1103/PhysRevA.56.1038 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA XL645 UT WOS:A1997XL64500122 ER PT J AU Lawrence, JM Chen, YC Kwei, GH Hundley, MF Thompson, JD AF Lawrence, JM Chen, YC Kwei, GH Hundley, MF Thompson, JD TI Structure and magnetism in CePt2+x SO PHYSICAL REVIEW B LA English DT Article AB Neutron diffraction results for CePt2+x alloys with 0 less than or equal to x less than or equal to 1, combined with low resolution room temperature x-ray diffraction and electron microscopy, confirm that the alloys are single phase. The data dan be fit for all x with nearly equal agreement factors by structural refinements in either the C15 (MgCu2) phase br the C15b (AuBe5) structure. Observation of small peaks in the diffraction pattern for CePt, that are forbidden in C15 suggest that C15b is the correct structure for this composition (and possibly for the other alloy compositions); and application of Hamilton's test indicates that the C15b structure is preferred over the C15 to the 95% confidence level. Magnetic susceptibility and specific heat measurements indicate that the cerium is essentially localized and trivalent for all x. The antiferromagnetism observed for CePt, may be absent in the alloys, which behave as typical nonmagnetic cerium heavy fermion compounds with Kondo temperature T-K approximate to 2 K. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP Lawrence, JM (reprint author), UNIV CALIF IRVINE,IRVINE,CA 92697, USA. NR 9 TC 9 Z9 9 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 JUL 1 PY 1997 VL 56 IS 1 BP 5 EP 8 DI 10.1103/PhysRevB.56.5 PG 4 WC Physics, Condensed Matter SC Physics GA XJ272 UT WOS:A1997XJ27200002 ER PT J AU Immer, CD Sarrao, JL Fisk, Z Lacerda, A Mielke, C Thompson, JD AF Immer, CD Sarrao, JL Fisk, Z Lacerda, A Mielke, C Thompson, JD TI Magnetic-field, pressure, and temperature scaling of the first-order valence transition in pure and doped YbInCu4 SO PHYSICAL REVIEW B LA English DT Article ID KONDO VOLUME-COLLAPSE; PHASE-TRANSITION; YBXIN1-XCU2; MODEL AB We report measurements of the high-field (H less than or equal to 30 T) magnetoresistance R(H,T) of pure and doped YbInCu4. A hysteretic transition is observed which we take to be the field-induced variant of the first-order valence transition observed;at 42 K in YbInCu4 for H=0 T. Applied pressure suppresses the:valence transition to lower temperature. By properly scaling the (H-v,T-v) data extracted from the resistance measurements, we can collapse all of the pressure-dependent data, as well as that from doped variants of YbInCu4 at ambient pressure, onto a universal H-T phase diagram. This suggests that a single energy scale is associated with the valence transition. C1 LOS ALAMOS NATL LAB,DIV MAT SCI & TECHNOL,LOS ALAMOS,NM 87545. RP Immer, CD (reprint author), FLORIDA STATE UNIV,NATL HIGH MAGNET FIELD LAB,1800 E PAUL DIRAC DR,TALLAHASSEE,FL 32306, USA. RI Mielke, Charles/S-6827-2016 OI Mielke, Charles/0000-0002-2096-5411 NR 32 TC 50 Z9 50 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 JUL 1 PY 1997 VL 56 IS 1 BP 71 EP 74 DI 10.1103/PhysRevB.56.71 PG 4 WC Physics, Condensed Matter SC Physics GA XJ272 UT WOS:A1997XJ27200019 ER PT J AU Kresin, VZ Bill, A Wolf, SA Ovchinnikov, YN AF Kresin, VZ Bill, A Wolf, SA Ovchinnikov, YN TI Unconventional isotope effects in superconductors SO PHYSICAL REVIEW B LA English DT Article ID CRITICAL MAGNETIC-FIELD; NORMAL-STATE; APEX-OXYGEN; CU-O; YBA2CU3O6+X; BA AB The value of the isotope coefficient could be greatly affected by a number of factors not related to the lattice dynamics. Among them are magnetic scattering, the presence Of a normal film (proximity effect), End nonadiabaticity (dynamic Jahn-Teller effect). The results are in good agreement with existing experimental data for oxygen isotope substitution (O-16-->O-18) in the YBa2Cu3O7-delta, Y1-xPrxBa2Cu3O7-delta, YBa2(Cu1-xZnx)(3)O7-delta compounds. In addition, we make several predictions related to conventional as well as to high-T-c materials. C1 USN, RES LAB, WASHINGTON, DC 20375 USA. LD LANDAU THEORET PHYS INST, MOSCOW 11733V, RUSSIA. RP Kresin, VZ (reprint author), UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA. RI Wolf, Stuart/A-7513-2009 NR 36 TC 41 Z9 41 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 JUL 1 PY 1997 VL 56 IS 1 BP 107 EP 110 DI 10.1103/PhysRevB.56.107 PG 4 WC Physics, Condensed Matter SC Physics GA XJ272 UT WOS:A1997XJ27200028 ER PT J AU Parks, B Spielman, S Orenstein, J AF Parks, B Spielman, S Orenstein, J TI High-frequency Hall effect in the normal state of YBa2Cu3O7 SO PHYSICAL REVIEW B LA English DT Article ID THIN-FILMS; ANGLE AB The ac Hall effect of YBa2Cu3O7 was measured in the normal state using time-domain spectroscopy. In contrast to some theories that explain the anomalous de Hall effect by postulating a much slower quasiparticle scattering rate for Hall conduction than for normal conduction, we report a Hall scattering rate that is consistent with the normal scattering rate. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV SCI MAT,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. RI Orenstein, Joseph/I-3451-2015 NR 12 TC 14 Z9 14 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 JUL 1 PY 1997 VL 56 IS 1 BP 115 EP 117 DI 10.1103/PhysRevB.56.115 PG 3 WC Physics, Condensed Matter SC Physics GA XJ272 UT WOS:A1997XJ27200030 ER PT J AU Yoo, CS Akella, J Cynn, H Nicol, M AF Yoo, CS Akella, J Cynn, H Nicol, M TI Direct elementary reactions of boron and nitrogen at high pressures and temperatures SO PHYSICAL REVIEW B LA English DT Article ID X-RAY-DIFFRACTION; PHASE-DIAGRAM; LOWER MANTLE; NITRIDE; CARBON; COMPRESSION; METALLIZATION; TRANSITION; CYANOGEN; DIAMOND AB Highly exothermic direct reactions between elements boron and nitrogen at high pressures and temperatures yield technologically important forms of hexagonal and cubic boron nitride (BN). The crystal structures of the reaction products vary with pressure. Below 10 GPa, hexagonal BN is the product; cubic or wurzite BN form at higher pressures. Under nitrogen-rich conditions, another hexagonal allotrope occurs; this seems to be a highly transparent, low density h'-BN. No direct reactions occur at ambient temperature even at pressures as high as 50 GPa, implying that a large activation barrier limits the kinetics of these exothermic processes. Direct reactions between boron and oxygen are also discussed. C1 UNIV CALIF LOS ANGELES,LOS ANGELES,CA 90095. RP Yoo, CS (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551, USA. NR 45 TC 51 Z9 52 U1 1 U2 8 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 JUL 1 PY 1997 VL 56 IS 1 BP 140 EP 146 DI 10.1103/PhysRevB.56.140 PG 7 WC Physics, Condensed Matter SC Physics GA XJ272 UT WOS:A1997XJ27200036 ER PT J AU Sidebottom, DL Green, PF Brow, RK AF Sidebottom, DL Green, PF Brow, RK TI Scaling parallels in the non-Debye dielectric relaxation of ionic glasses and dipolar supercooled liquids SO PHYSICAL REVIEW B LA English DT Article ID AC CONDUCTIVITY DATA; ELECTRICAL RELAXATION; OXIDE GLASSES; CONDUCTORS; MODEL; SUSCEPTIBILITY; TRANSITION; DIFFUSION; TRANSPORT AB We compare the dielectric response of ionic glasses and dipolar liquids near the glass transition. Our work is divided into two parts. In the first section we examine ionic glasses and the two prominent approaches to analyzing the dielectric response. The conductivity of ion-conducting glasses displays a power law dispersion sigma(omega)proportional to omega(n), where n approximate to 0.67, but frequently the dielectric response is analyzed using the electrical modulus M*(omega)=1/epsilon*(omega), where epsilon*(omega)=epsilon(omega)-i sigma(omega)/omega is the complex permittivity. We reexamine two specific examples where the shape of M*(omega) changes in response to changes in (a) temperature and (b) ion concentration, to suggest fundamental changes in ion dynamics are occurring. We show, however, that these changes in the shape of M*(omega) occur in the absence of changes in the scaling properties of ate), for which rt remains constant. in the second part, we examine the dielectric relaxation found in dipolar liquids, for which epsilon*(omega) likewise exhibits changes in shape on approach to the glass transition. Guided by similarities of M*(omega) in ionic glasses and epsilon*(omega) in dipolar liquids, we demonstrate that a recent scaling approach proposed by Dixon and co-workers for epsilon*(omega) Of dipolar relaxation also appears valid for M*(omega) in the ionic case. While this suggests that the Dixon scaling approach is more universal than previously recognized, we demonstrate how the dielectric response can be scaled in a linear manner using an alternative data representation.. RP Sidebottom, DL (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 39 TC 58 Z9 58 U1 1 U2 8 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 JUL 1 PY 1997 VL 56 IS 1 BP 170 EP 177 DI 10.1103/PhysRevB.56.170 PG 8 WC Physics, Condensed Matter SC Physics GA XJ272 UT WOS:A1997XJ27200041 ER PT J AU Bhatnagar, AK Rathnayaka, KDD Naugle, DG Canfield, PC AF Bhatnagar, AK Rathnayaka, KDD Naugle, DG Canfield, PC TI Electrical resistivity and thermopower of single-crystal RNi2B2C (R=Dy, Ho, Er, Tm) magnetic superconductors SO PHYSICAL REVIEW B LA English DT Article ID HIGH-TC SUPERCONDUCTORS; ELECTRONIC-STRUCTURE; LUNI2B2C; ERNI2B2C; TMNI2B2C; HEAT; COMPETITION; DYNI2B2C; HONI2B2C; YNI2B2C AB The in-plane resistivity rho and thermopower S of single crystal RNi2B2C (R=Dy, Ho, Er, Tm) has been measured from 4 to 300 K. The resistivity is linear in temperature from about 100 to 300 K, but the low-temperature dependence goes as T-p With p = 3.0, 2.6, 2.0, and 1.4, respectively, from Dy to Tm, in comparison to the T-2 behavior previously reported for LuNi2B2C. The thermopower exhibits a region linear in T from about 100 to 300 K where the coefficient b scales by the de Gennes factor (g-1)(2)J(J+1) for different R = Lu, Tm-Dy. The quantity S-b T is surprisingly similar in temperature dependence and magnitude for samples with R = Y, Lu, Dy-Tm, suggesting a common, nonmagnetic contribution to the thermopower of these compounds. C1 UNIV HYDERABAD, DEPT PHYS, HYDERABAD 500046, ANDHRA PRADESH, INDIA. IOWA STATE UNIV SCI & TECHNOL, AMES, IA 50011 USA. AMES LAB, DEPT PHYS, AMES, IA 50011 USA. RP TEXAS A&M UNIV, DEPT PHYS, COLLEGE STN, TX 77843 USA. RI Canfield, Paul/H-2698-2014; OI Bhatnagar, Anil/0000-0002-7998-2793 NR 55 TC 21 Z9 21 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9950 EI 2469-9969 J9 PHYS REV B JI Phys. Rev. B PD JUL 1 PY 1997 VL 56 IS 1 BP 437 EP 445 DI 10.1103/PhysRevB.56.437 PG 9 WC Physics, Condensed Matter SC Physics GA XJ272 UT WOS:A1997XJ27200073 ER PT J AU Abrikosov, AA AF Abrikosov, AA TI Ginzburg-Landau equations for the extended saddle-point model SO PHYSICAL REVIEW B LA English DT Article ID UPPER CRITICAL-FIELD; SR-CU-O; SINGLE-CRYSTAL; THIN-FILMS; SUPERCONDUCTIVITY; TEMPERATURE; TL2BA2CUO6; TRANSPORT; ORDER AB Ginzburg-Landau-type equations are derived describing the model of tetragonal high-temperature superconducting cuprates based on the dominant role of extended saddle-point singularities in the electron spectrum and the assumption that the interaction between electrons consists of a strong long-range phonon-mediated attraction and a weak short-range repulsion. The connection between CuO2 layers is assumed to be established by resonant tunneling. As an example, the temperature dependence of the upper critical field along the c axis is calculated, which appears to have a positive curvature, as observed in many experiments. This is explained by the fact that with departure from T-c the connection between different singular points becomes increasingly less important, and the electrons become more one-dimensional. Other explanations an briefly discussed. RP Abrikosov, AA (reprint author), ARGONNE NATL LAB,DIV MAT SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 32 TC 29 Z9 29 U1 1 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 JUL 1 PY 1997 VL 56 IS 1 BP 446 EP 452 DI 10.1103/PhysRevB.56.446 PG 7 WC Physics, Condensed Matter SC Physics GA XJ272 UT WOS:A1997XJ27200074 ER PT J AU Lorenzana, HE Klepeis, JE Lipp, MJ Evans, WJ Radousky, HB vanSchilfgaarde, M AF Lorenzana, HE Klepeis, JE Lipp, MJ Evans, WJ Radousky, HB vanSchilfgaarde, M TI High-pressure phases of PbF2: A joint experimental and theoretical study SO PHYSICAL REVIEW B LA English DT Article ID DIAMOND-ANVIL CELL; ORTHORHOMBIC LEAD FLUORIDE; ALKALINE-EARTH FLUORIDES; SUPERIONIC CRYSTALS; IONIC-CONDUCTIVITY; RAMAN-SCATTERING; AX(2) COMPOUNDS; TEMPERATURE; CALORIMETRY; DEPENDENCES AB We report a joint experimental and theoretical study of the dynamical and structural properties of lead fluoride (PbF2). Specifically, we have performed detailed measurements of the room-temperature Raman-active phonon modes to 310 kbar. We verify the transition at about 4 kbar from the cubic (beta) to the orthorhombic (alpha) phase and the recovery of the alpha phase at ambient conditions. At approximately 147 kbar, we observe a transformation from the alpha phase to a modification that we label gamma. The data indicate that the gamma phase is structurally similar to the orthorhombic alpha phase. Moreover, we have carried out first-principles calculations which support the existence of a transition in this pressure range, although the crystal structure of the new phase remains undetermined. We have also calculated the equations of state for the two low-pressure phases, beta and alpha. In the case of the alpha phase, we have made a complete structural determination by calculating the pressure-dependent values of all six internal structural parameters as well as the axial ratios, c/a and b/a, for pressures ranging from zero up to 2 Mbar. Using the calculated alpha-phase equation of state, we also extract Gruneisen parameters from the data for several optical phonon modes. C1 SRI INT, MENLO PK, CA 94025 USA. RP Lorenzana, HE (reprint author), LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94551 USA. NR 45 TC 23 Z9 24 U1 1 U2 5 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 JUL 1 PY 1997 VL 56 IS 2 BP 543 EP 551 DI 10.1103/PhysRevB.56.543 PG 9 WC Physics, Condensed Matter SC Physics GA XL827 UT WOS:A1997XL82700017 ER PT J AU Feyerherm, R Amato, A Geibel, C Gygax, FN Hellmann, P Heffner, RH MacLaughlin, DE MullerReisener, R AF Feyerherm, R Amato, A Geibel, C Gygax, FN Hellmann, P Heffner, RH MacLaughlin, DE MullerReisener, R TI Competition between magnetism and superconductivity in CeCu2Si2 SO PHYSICAL REVIEW B LA English DT Article ID HEAVY-FERMION SUPERCONDUCTIVITY; MUON SPIN RELAXATION; KONDO LATTICE; PHASE-DIAGRAM; FIELD; SYSTEMS; ANTIFERROMAGNETISM; COEXISTENCE; PRESSURE; UPD2AL3 AB The interplay between superconductivity and magnetism in CeCu2Si2 has been investigated by means of microprobe, muon spin rotation and relaxation (mu SR), and specific-heat measurements on four slightly off-stoichiometric polycrystalline samples Ce1+xCu2+ySi2. Microprobe analysis reveals that within the errors (+/-3%) the main phases of all four samples exhibit the ideal stoichiometry 1:2:2 and their relative composition varies by less than 2%. Muon spin rotation and relaxation measurements, however, reveal pronounced differences in their ground states. The nonsuperconducting sample Ce0.99Cu2.02Si2 exhibits a phase transition at T-m=0.67 K to a magnetically ordered ground state of unknown structure, with a lower limit on the size of the frozen moments mu approximate to 0.2 mu(B). For Tmu(nu)over-bar(mu)gamma and B->e(nu)over-bar(e)gamma SO PHYSICAL REVIEW D LA English DT Article ID B-MESONS; HEAVY MESONS; DECAYS AB We have searched for the decays B-->mu (v) over bar(mu)gamma and B-->e (v) over bar(e) gamma in a sample of 2.7 x 10(6) charged B decays collected with the CLEO II detector. In the muon channel, we observe no candidates in the signal region and set an upper limit on the branching fraction of B(B-->mu (v) over bar(mu)gamma) < 5.2 x 10(-5) at the 90% confidence level. In the electron channel. we observe five candidates in the signal region and set an upper limit on the branching fraction of B(B-->e (v) over bar(e) gamma) < 2.0 x 10(-4) at the 90% confidence level. C1 UNIV ILLINOIS,CHAMPAIGN,IL 61801. CARLETON UNIV,OTTAWA,ON K1S 5B6,CANADA. MCGILL UNIV,INST PARTICLE PHYS,MONTREAL,PQ H3A 2T8,CANADA. ITHACA COLL,ITHACA,NY 14850. UNIV KANSAS,LAWRENCE,KS 66045. UNIV MINNESOTA,MINNEAPOLIS,MN 55455. SUNY ALBANY,ALBANY,NY 12222. OHIO STATE UNIV,COLUMBUS,OH 43210. UNIV OKLAHOMA,NORMAN,OK 73019. PURDUE UNIV,W LAFAYETTE,IN 47907. UNIV ROCHESTER,ROCHESTER,NY 14627. STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309. SO METHODIST UNIV,DALLAS,TX 75275. SYRACUSE UNIV,SYRACUSE,NY 13244. VANDERBILT UNIV,NASHVILLE,TN 37235. VIRGINIA POLYTECH INST & STATE UNIV,BLACKSBURG,VA 24061. WAYNE STATE UNIV,DETROIT,MI 48202. CALTECH,PASADENA,CA 91125. UNIV CALIF SAN DIEGO,LA JOLLA,CA 92093. UNIV CALIF SANTA BARBARA,SANTA BARBARA,CA 93106. UNIV COLORADO,BOULDER,CO 80309. CORNELL UNIV,ITHACA,NY 14853. UNIV FLORIDA,GAINESVILLE,FL 32611. HARVARD UNIV,CAMBRIDGE,MA 02138. BINP,RU-630090 NOVOSIBIRSK,RUSSIA. UNIV TEXAS,AUSTIN,TX 78712. RP Browder, TE (reprint author), UNIV HAWAII MANOA,HONOLULU,HI 96822, USA. RI Schaffner, Stephen/D-1189-2011; Briere, Roy/N-7819-2014; Frasconi, Franco/K-1068-2016 OI Briere, Roy/0000-0001-5229-1039; Frasconi, Franco/0000-0003-4204-6587 NR 22 TC 11 Z9 11 U1 1 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD JUL 1 PY 1997 VL 56 IS 1 BP 11 EP 16 DI 10.1103/PhysRevD.56.11 PG 6 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA XH857 UT WOS:A1997XH85700003 ER PT J AU Alam, MS Athar, SB Ling, Z Mahmood, AH Severini, H Timm, S Wappler, F Anastassov, A Blinov, S Duboscq, JE Fujino, D Fulton, R Gan, KK Hart, T Honscheid, K Kagan, H Kass, R Lee, J Spencer, MB Sung, M Undrus, A Wanke, R Wolf, A Zoeller, MM Nemati, B Richichi, SJ Ross, WR Skubic, P Wood, M Bishai, M Fast, J Gerndt, E Hinson, JW Menon, N Miller, DH Shibata, EI Shipsey, IPJ Yurko, M Gibbons, L Johnson, SD Kwon, Y Roberts, S Thorndike, EH Jessop, CP Lingel, K Marsiske, H Perl, ML Schaffner, SF Ugolini, D Wang, R Zhou, X Coan, TE Fadeyev, V Korolkov, I Maravin, Y Narsky, I Shelkov, V Staeck, J Stroynowski, R Volobouev, I Ye, J Artuso, M Efimov, A Frasconi, F Gao, M Goldberg, M He, D Kopp, S Moneti, GC Mountain, R Mukhin, Y Schuh, S Skwarnicki, T Stone, S Viehhauser, G Xing, X Bartelt, J Csorna, SE Jain, V Marka, S Freyberger, A Gibaut, D Godang, R Kinoshita, K Lai, IC Pomianowski, P Schrenk, S Bonvicini, G Cinabro, D Greene, R Perera, LP Barish, B Chadha, M Chan, S Eigen, G Miller, JS OGrady, C Schmidtler, M Urheim, J Weinstein, AJ Wurthwein, F Asner, DM Bliss, DW Brower, WS Masek, G Paar, HP Sivertz, M Gronberg, J Kutschke, R Lange, DJ Menary, S Morrison, RJ Nakanishi, S Nelson, HN Nelson, TK Qiao, C Richman, JS Roberts, D Ryd, A Tajima, H Witherell, MS Balest, R Behrens, BH Cho, K Ford, WT Park, H Rankin, P Roy, J Smith, JG Alexander, JP Bebek, C Berger, BE Berkelman, K Bloom, K Cassel, DG Cho, HA Coffman, DM Crowcroft, DS Dickson, M Drell, PS Ecklund, KM Ehrlich, R Elia, R Foland, AD Gaidarev, P Galik, RS Gittelman, B Gray, SW Hartill, DL Heltsley, BK Hopman, PI Jones, SL Kandaswamy, J Katayama, N Kim, PC Kreinick, DL Lee, T Liu, Y Ludwig, GS Masui, J Mevissen, J Mistry, NB Ng, CR Nordberg, E Ogg, M Patterson, JR Peterson, D Riley, D Soffer, A Ward, C Athanas, M Avery, P Jones, CD Lohner, M Prescott, C Yang, S Yelton, J Zheng, J Brandenburg, G Briere, RA Gao, YS Kim, DYJ Wilson, R Yamamoto, H Browder, TE Li, F Li, Y Rodriguez, JL Bergfeld, T Eisenstein, BI Ernst, J Gladding, GE Gollin, GD Hans, RM Johnson, E Karliner, I Marsh, MA Palmer, M Selen, M Thaler, JJ Edwards, KW Bellerive, A Janicek, R MacFarlane, DB McLean, KW Patel, PM Sadoff, AJ Ammar, R Baringer, P Bean, A Besson, D Coppage, D Darling, C Davis, R Hancock, N Kotov, S Kravchenko, I Kwak, N Anderson, S Kubota, Y Lattery, M ONeill, JJ Patton, S Poling, R Riehle, T Savinov, V Smith, A AF Alam, MS Athar, SB Ling, Z Mahmood, AH Severini, H Timm, S Wappler, F Anastassov, A Blinov, S Duboscq, JE Fujino, D Fulton, R Gan, KK Hart, T Honscheid, K Kagan, H Kass, R Lee, J Spencer, MB Sung, M Undrus, A Wanke, R Wolf, A Zoeller, MM Nemati, B Richichi, SJ Ross, WR Skubic, P Wood, M Bishai, M Fast, J Gerndt, E Hinson, JW Menon, N Miller, DH Shibata, EI Shipsey, IPJ Yurko, M Gibbons, L Johnson, SD Kwon, Y Roberts, S Thorndike, EH Jessop, CP Lingel, K Marsiske, H Perl, ML Schaffner, SF Ugolini, D Wang, R Zhou, X Coan, TE Fadeyev, V Korolkov, I Maravin, Y Narsky, I Shelkov, V Staeck, J Stroynowski, R Volobouev, I Ye, J Artuso, M Efimov, A Frasconi, F Gao, M Goldberg, M He, D Kopp, S Moneti, GC Mountain, R Mukhin, Y Schuh, S Skwarnicki, T Stone, S Viehhauser, G Xing, X Bartelt, J Csorna, SE Jain, V Marka, S Freyberger, A Gibaut, D Godang, R Kinoshita, K Lai, IC Pomianowski, P Schrenk, S Bonvicini, G Cinabro, D Greene, R Perera, LP Barish, B Chadha, M Chan, S Eigen, G Miller, JS OGrady, C Schmidtler, M Urheim, J Weinstein, AJ Wurthwein, F Asner, DM Bliss, DW Brower, WS Masek, G Paar, HP Sivertz, M Gronberg, J Kutschke, R Lange, DJ Menary, S Morrison, RJ Nakanishi, S Nelson, HN Nelson, TK Qiao, C Richman, JS Roberts, D Ryd, A Tajima, H Witherell, MS Balest, R Behrens, BH Cho, K Ford, WT Park, H Rankin, P Roy, J Smith, JG Alexander, JP Bebek, C Berger, BE Berkelman, K Bloom, K Cassel, DG Cho, HA Coffman, DM Crowcroft, DS Dickson, M Drell, PS Ecklund, KM Ehrlich, R Elia, R Foland, AD Gaidarev, P Galik, RS Gittelman, B Gray, SW Hartill, DL Heltsley, BK Hopman, PI Jones, SL Kandaswamy, J Katayama, N Kim, PC Kreinick, DL Lee, T Liu, Y Ludwig, GS Masui, J Mevissen, J Mistry, NB Ng, CR Nordberg, E Ogg, M Patterson, JR Peterson, D Riley, D Soffer, A Ward, C Athanas, M Avery, P Jones, CD Lohner, M Prescott, C Yang, S Yelton, J Zheng, J Brandenburg, G Briere, RA Gao, YS Kim, DYJ Wilson, R Yamamoto, H Browder, TE Li, F Li, Y Rodriguez, JL Bergfeld, T Eisenstein, BI Ernst, J Gladding, GE Gollin, GD Hans, RM Johnson, E Karliner, I Marsh, MA Palmer, M Selen, M Thaler, JJ Edwards, KW Bellerive, A Janicek, R MacFarlane, DB McLean, KW Patel, PM Sadoff, AJ Ammar, R Baringer, P Bean, A Besson, D Coppage, D Darling, C Davis, R Hancock, N Kotov, S Kravchenko, I Kwak, N Anderson, S Kubota, Y Lattery, M ONeill, JJ Patton, S Poling, R Riehle, T Savinov, V Smith, A TI Study of gluon versus quark fragmentation in Y->gg gamma and e(+)e(-)->q(q)over-bar gamma events at root s=10 GeV SO PHYSICAL REVIEW D LA English DT Article ID MULTIPLICITY DISTRIBUTIONS; AVERAGE MULTIPLICITIES; JETS; LEP; QCD AB Using data collected with the CLEO II detector at the Cornell Electron Storage Ring, we determine the ratio R-chrg for the mean charged multiplicity observed in Y(1S)-->gg gamma events, [n(gluon)(+/1)], to the mean charged multiplicity observed in e(+)e(-)-->q (q) over bar gamma events, [n(quark)(+/-)]. We find R-charg = [n(gluon)(+/-)]/[n(quark)(+/-)] = 1.04 +/- 0.02(stat) +/- 0.05(syst) for jet-jet masses less than 7 GeV. C1 OHIO STATE UNIV,COLUMBUS,OH 43210. UNIV OKLAHOMA,NORMAN,OK 73019. PURDUE UNIV,W LAFAYETTE,IN 47907. UNIV ROCHESTER,ROCHESTER,NY 14627. STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309. SO METHODIST UNIV,DALLAS,TX 75275. SYRACUSE UNIV,SYRACUSE,NY 13244. VANDERBILT UNIV,NASHVILLE,TN 37235. VIRGINIA POLYTECH INST & STATE UNIV,BLACKSBURG,VA 24061. WAYNE STATE UNIV,DETROIT,MI 48202. CALTECH,PASADENA,CA 91125. UNIV CALIF SAN DIEGO,LA JOLLA,CA 92093. UNIV CALIF SANTA BARBARA,SANTA BARBARA,CA 93106. UNIV COLORADO,BOULDER,CO 80309. CORNELL UNIV,ITHACA,NY 14853. UNIV FLORIDA,GAINESVILLE,FL 32611. HARVARD UNIV,CAMBRIDGE,MA 02138. UNIV HAWAII MANOA,HONOLULU,HI 96822. UNIV ILLINOIS,CHAMPAIGN,IL 61801. CARLETON UNIV,OTTAWA,ON K1S 5B6,CANADA. INST PARTICLE PHYS,OTTAWA,ON K1S 5B6,CANADA. INST PARTICLE PHYS,MONTREAL,PQ H3A 2T8,CANADA. BINP,RU-630090 NOVOSIBIRSK,RUSSIA. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551. UNIV TEXAS,AUSTIN,TX 78712. ITHACA COLL,ITHACA,NY 14850. UNIV KANSAS,LAWRENCE,KS 66045. UNIV MINNESOTA,MINNEAPOLIS,MN 55455. RP Alam, MS (reprint author), SUNY ALBANY,ALBANY,NY 12222, USA. RI Schaffner, Stephen/D-1189-2011; Briere, Roy/N-7819-2014; Frasconi, Franco/K-1068-2016 OI Briere, Roy/0000-0001-5229-1039; Frasconi, Franco/0000-0003-4204-6587 NR 30 TC 31 Z9 31 U1 1 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD JUL 1 PY 1997 VL 56 IS 1 BP 17 EP 22 DI 10.1103/PhysRevD.56.17 PG 6 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA XH857 UT WOS:A1997XH85700004 ER PT J AU Herczeg, P Khriplovich, IB AF Herczeg, P Khriplovich, IB TI Time-reversal violation in beta decay in the standard model SO PHYSICAL REVIEW D LA English DT Article ID ELECTRIC-DIPOLE MOMENT; KOBAYASHI-MASKAWA MODEL; CP-VIOLATION; NONLEPTONIC DECAYS; STRANGE PARTICLES; DELTA-I=1-2 RULE; WEAK DECAYS; T-ODD; NEUTRON; INVARIANCE AB We estimate the size of time-reversal violation in beta decay due to the Kobayashi-Maskawa phase delta, and the theta term L(t)heta. We find that the contribution of delta to the D and R correlations is not likely to be larger than of thp older of 10(-12)\a\(\s(2)s(3)s(delta)\/10(-3)) and 10(-14)\a\(\s(2)s(3)s(delta)\/10(-3)), respectively, where \a\ similar or equal to 1 fur neutron and Ne-19 decay. For the contribution of L theta to D and R we conclude that it is not likely to be larger than of the order of 10(-14)\a\(\theta\/3 x 10(-10))Q/(m(n) - m(p)) and 10(-12)\a\(\theta\/3 x 10(-10)), respectively (the present experimental limits on s(2)s(3)s(delta) and theta are \s(2)s(3)s(delta)\ less than or similar to 10(-3) and \theta\ less than or similar to 3 x 10(-10)), where Q is the energy release in the decay. For both delta and L-theta the D and R coefficients ate dominated by long-distance contributions. The small values of D and R in the standard model compared to the best experimental limit on T-odd correlations (10(-1) for D in Ne-19 decay) give potentially a wide window in which T-violating interactions beyond the standard model can be searched for. However, the range in this window that one will be able to exploit depends on the level at which the contributions of the final-state interactions can be kept under control. C1 BUDKER INST NUCL PHYS, NOVOSIBIRSK 630090, RUSSIA. RP LOS ALAMOS NATL LAB, DIV THEORET, LOS ALAMOS, NM 87545 USA. RI Khriplovich, Iosif/N-5679-2015 OI Khriplovich, Iosif/0000-0001-8088-6363 NR 58 TC 31 Z9 31 U1 0 U2 4 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0010 EI 2470-0029 J9 PHYS REV D JI Phys. Rev. D PD JUL 1 PY 1997 VL 56 IS 1 BP 80 EP 89 DI 10.1103/PhysRevD.56.80 PG 10 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA XH857 UT WOS:A1997XH85700011 ER PT J AU Blum, T Soni, A AF Blum, T Soni, A TI QCD with domain wall quarks SO PHYSICAL REVIEW D LA English DT Article ID CHIRAL GAUGE-THEORIES; KAON B-PARAMETER; LATTICE QCD; 4-FERMION OPERATORS; WILSON FERMIONS; WAVE-GUIDE; BREAKING; SYMMETRY; OVERLAP AB We present lattice calculations in QCD using Shamir's variant of Kaplan fermions which retain the continuum SU(N)(L) x SU(N)(R) chiral symmetry on the lattice in the limit of an infinite extra dimension. In particular, we show that the pion mass and the four quark matrix element related to K-0-K-0 mixing have the expected behavior in the chiral limit, even on lattices with modest extent in the extra dimension. e.g. N-3 = 10. RP BROOKHAVEN NATL LAB, DEPT PHYS, UPTON, NY 11973 USA. NR 33 TC 86 Z9 86 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0010 EI 2470-0029 J9 PHYS REV D JI Phys. Rev. D PD JUL 1 PY 1997 VL 56 IS 1 BP 174 EP 178 DI 10.1103/PhysRevD.56.174 PG 5 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA XH857 UT WOS:A1997XH85700020 ER PT J AU Blumenfeld, R Mandelbrot, BB AF Blumenfeld, R Mandelbrot, BB TI Levy dusts, Mittag-Leffler statistics, mass fractal lacunarity, and perceived dimension SO PHYSICAL REVIEW E LA English DT Article ID SELF-SIMILARITY; PLANE DLA; FLUCTUATIONS; NETWORKS; FIELD AB We study the Livy dusts on the Line on two accounts: the fluctuations around the average power law that characterizes the mass-radius relation for self-similar fractals, and the statistics of the intervals between strides alone the logarithmic axis (their tail distribution is related to the dust's fractal dimension). The Levy dusts are suggested as a yardstick of neutral lacunarity, against which non-neutral lacunarity can be measured objectively. A notion of perceived dimension is introduced. We conclude with an application of the Mittag-Leffler statistics to a nonlinear electrical network. C1 YALE UNIV,DEPT MATH,NEW HAVEN,CT 06520. RP Blumenfeld, R (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,MAIL STOP B262,LOS ALAMOS,NM 87545, USA. NR 20 TC 27 Z9 27 U1 1 U2 9 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 JUL PY 1997 VL 56 IS 1 BP 112 EP 118 DI 10.1103/PhysRevE.56.112 PN A PG 7 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA XM375 UT WOS:A1997XM37500025 ER PT J AU Aiba, H Mizutori, S Suzuki, T AF Aiba, H Mizutori, S Suzuki, T TI Fluctuation properties of strength function phenomena: A model study SO PHYSICAL REVIEW E LA English DT Article ID HAMILTONIAN-SYSTEMS; QUANTUM-MECHANICS; CLASSICAL MOTION; LEVEL STATISTICS; TRANSITION; CHAOS; MANIFESTATIONS; SPECTRA AB We study fluctuation properties of strength function phenomena by employing a quantum mechanical model where a single parent state couples with a large number of background states. The background system is devised in such a way that the classical dynamics of the system may show a regular, an irregular, or a chaotic character as a function of a single parameter. The coupling of the parent state to the background states produces a fragmentation of the parent state, giving rise to a strength function phenomenon. We study various measures of the strength function that characterize its bulk structure or fluctuation properties. They include energy moments, strength distribution, fractal dimensions of the strength function, and Fourier transform of the autocorrelation function. Some of these measures, such as strength distribution or Fourier transform of the autocorrelation function, reflect characteristic aspects of the dynamics of the background system, i.e., if they have a regular or a chaotic character, while measures such as energy moments or fractal dimensions are rather insensitive to the dynamics. C1 OAK RIDGE NATL LAB,JOINT INST HEAVY ION RES,OAK RIDGE,TN 37831. UNIV TENNESSEE,DEPT PHYS & ASTRON,KNOXVILLE,TN 37831. TOKYO METROPOLITAN UNIV,DEPT PHYS,HACHIOJI,TOKYO 19203,JAPAN. KOKA WOMENS COLL,UKYO KU,KYOTO 615,JAPAN. RP Aiba, H (reprint author), KYOTO UNIV,YUKAWA INST THEORET PHYS,KYOTO 60601,JAPAN. NR 27 TC 7 Z9 7 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 JUL PY 1997 VL 56 IS 1 BP 119 EP 130 DI 10.1103/PhysRevE.56.119 PN A PG 12 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA XM375 UT WOS:A1997XM37500026 ER PT J AU Reynolds, WN PonceDawson, S Pearson, JE AF Reynolds, WN PonceDawson, S Pearson, JE TI Self-replicating spots in reaction-diffusion systems SO PHYSICAL REVIEW E LA English DT Article ID BIOLOGICAL PATTERN-FORMATION AB In a recent article [Phys. Rev. Lett. 72, 2797 (1994)] we analyzed the phenomena of self-replicating spots in the Gray-Scott model. In this article we present those results in detail and generalize them to a class of models that derives from our heuristic explanation of spot replication. C1 UNIV BUENOS AIRES, FAC CIENCIAS EXACTAS & NAT, DEPT FIS, RA-1428 BUENOS AIRES, DF, ARGENTINA. UNIV BUENOS AIRES, FAC CIENCIAS EXACTAS & NAT, IAFE, RA-1428 BUENOS AIRES, DF, ARGENTINA. LOS ALAMOS NATL LAB, DIV APPL THEORET PHYS, LOS ALAMOS, NM 87545 USA. RP LOS ALAMOS NATL LAB, DIV THEORET, COMPLEX SYST GRP, LOS ALAMOS, NM 87545 USA. OI Ponce Dawson, Silvina/0000-0001-6550-4267 NR 25 TC 82 Z9 82 U1 0 U2 1 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 JUL PY 1997 VL 56 IS 1 BP 185 EP 198 DI 10.1103/PhysRevE.56.185 PN A PG 14 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA XM375 UT WOS:A1997XM37500032 ER PT J AU Kennel, MB AF Kennel, MB TI Statistical test for dynamical nonstationarity in observed time-series data SO PHYSICAL REVIEW E LA English DT Article ID DIMENSION; SYSTEMS AB Information in the time distribution of points in a state space reconstructed from observed data yields a test for ''nonstationarity.'' Framed in terms of a statistical hypothesis test, this numerical algorithm can discern whether some underlying slow changes in parameters have taken place. The method examines a fundamental object in nonlinear dynamics; the geometry of orbits in state space, with corrections to overcome difficulties in real dynamical data which cause naive statistics to fail. RP Kennel, MB (reprint author), OAK RIDGE NATL LAB,ENGN TECHNOL DIV,MS 8088,OAK RIDGE,TN 37831, USA. NR 16 TC 55 Z9 59 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 JUL PY 1997 VL 56 IS 1 BP 316 EP 321 DI 10.1103/PhysRevE.56.316 PN A PG 6 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA XM375 UT WOS:A1997XM37500051 ER PT J AU He, XY Doolen, GD AF He, XY Doolen, GD TI Lattice Boltzmann method on a curvilinear coordinate system: Vortex shedding behind a circular cylinder SO PHYSICAL REVIEW E LA English DT Article ID NAVIER-STOKES EQUATION; LOW REYNOLDS NUMBERS; GAS AUTOMATA; FLOW; SIMULATIONS; DRAG; PRESSURE; WAKE AB The interpolatino-supplemented lattice Boltzmann equation (ISLBE) method is used to simulate the two-dimensianal vortex shedding behind a circular cylinder at low Reynolds numbers. Simulations are carried out on a polar-coordinate grid system with a dense grid distributed near the cylinder surface. The Strouhal number, the drag,and the lift coefficients obtained from the simulations agree well with previous experimental measurements and classical computational fluid dynamics simulations. Comparisons of detailed flow; patterns with other studies via streamlines and streaklines are also satisfactory. The ability of the ISLBE scheme to simulate complicated long-term periodic flow phenomena is demonstrated. C1 LOS ALAMOS NATL LAB,DIV THEORET,GRP T13,LOS ALAMOS,NM 87545. RP He, XY (reprint author), LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES,MS-B258,LOS ALAMOS,NM 87545, USA. NR 32 TC 71 Z9 75 U1 2 U2 9 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 JUL PY 1997 VL 56 IS 1 BP 434 EP 440 DI 10.1103/PhysRevE.56.434 PN A PG 7 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA XM375 UT WOS:A1997XM37500064 ER PT J AU Kum, O Hoover, WG Hoover, CG AF Kum, O Hoover, WG Hoover, CG TI Temperature maxima in stable two-dimensional shock waves SO PHYSICAL REVIEW E LA English DT Article ID PARTICLE APPLIED MECHANICS; MOLECULAR-DYNAMICS; CONTINUUM-MECHANICS; VISCOSITY; FLOWS; FLUID AB We use molecular dynamics to study the structure oi moderately strong shock waves in dense two-dimensional fluids, using Lucy's pair potential, The stationary profiles show relatively broad temperature maxima, for both the longitudinal land the average kinetic temperatures, just as does Mott-Smith's model for strong shock waves In dilute three-dimensional gases. C1 UNIV CALIF DAVIS,DEPT APPL SCI,LIVERMORE,CA 94551. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551. RP Kum, O (reprint author), AGCY DEF DEV,POB 35,TAEJON 300600,SOUTH KOREA. RI Kum, Oyeon/A-4962-2008 NR 16 TC 15 Z9 15 U1 0 U2 1 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 JUL PY 1997 VL 56 IS 1 BP 462 EP 465 DI 10.1103/PhysRevE.56.462 PN A PG 4 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA XM375 UT WOS:A1997XM37500067 ER PT J AU Heading, DJ Wark, JS Lee, RW Stamm, R Talin, B AF Heading, DJ Wark, JS Lee, RW Stamm, R Talin, B TI Comparison of the semiclassical and modified semiempirical method of spectral calculation SO PHYSICAL REVIEW E LA English DT Article ID STARK WIDTHS; PLASMA; LINES AB In recent experiments the capacity has been developed to generate plasmas at high densities. Standard methods used to diagnose plasmas are difficult to apply at these conditions, since it is necessary to calculate the entire spectrum as there is significant overlap of spectral lines. However, for most elements, the number of individual spectral line profiles calculated using the semiclassical method is very small. We present a method to use an approximate line width formula, coupled with an accurate database to generate a large number of line profiles. We evaluate the accuracy and utility of such an approach by comparison with semiclassical calculations. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551. UNIV AIX MARSEILLE 1,CTR ST JEROME,PIIM,URA 773,F-13397 MARSEILLE 20,FRANCE. RP Heading, DJ (reprint author), UNIV OXFORD,DEPT PHYS,CLARENDON LAB,PARKS RD,OXFORD OX1 3PU,ENGLAND. NR 25 TC 6 Z9 7 U1 0 U2 1 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 JUL PY 1997 VL 56 IS 1 BP 936 EP 946 DI 10.1103/PhysRevE.56.936 PN B PG 11 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA XM377 UT WOS:A1997XM37700050 ER PT J AU Holian, BL Thomson, R AF Holian, BL Thomson, R TI Crack limiting velocity SO PHYSICAL REVIEW E LA English DT Article ID FRACTURE; DYNAMICS AB We address the question of how a dynamic crack can approach zero velocity. Continuum theories usually do not explicitly include the radiation of energy away from the crack tip. We show that its inclusion leads to the prediction of crack velocity that increases smoothly (though sharply) from zero. We then connect an older, simple model of crack propagation (''atoms on rails'') to a recently proposed single-particle model and show how the disappearance of lattice trapping leads to a smooth low-velocity limit. C1 NATL INST STAND & TECHNOL,MAT SCI & ENGN LAB,GAITHERSBURG,MD 20899. RP Holian, BL (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. NR 16 TC 4 Z9 4 U1 0 U2 2 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 JUL PY 1997 VL 56 IS 1 BP 1071 EP 1079 DI 10.1103/PhysRevE.56.1071 PN B PG 9 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA XM377 UT WOS:A1997XM37700065 ER PT J AU Zhang, DS Wei, GW Kouri, DJ Hoffman, DK AF Zhang, DS Wei, GW Kouri, DJ Hoffman, DK TI Numerical method for the nonlinear Fokker-Planck equation SO PHYSICAL REVIEW E LA English DT Article ID MEAN-FIELD MODEL; FLUCTUATIONS; DIFFUSION; BEHAVIOR; INTEGRATION; DYNAMICS AB A practical method based on distributed approximating functionals (DAFs) is proposed for numerically solving a general class of nonlinear time-dependent Fokker-Planck equations. The method relies on a numerical scheme that couples the usual path-integral concept to the DAF idea. The high accuracy and reliability of the method are illustrated by applying it to an exactly solvable nonlinear Fokker-Planck equation, and the method is compared with the accurate K-point Stirling interpolation formula finite-difference method. The approach is also used successfully to solve a nonlinear self-consistent dynamic mean-field problem for which both the cumulant expansion and scaling theory have been found by Drozdov and Morillo [Phys. Rev. E 54, 931 (1996)] to be inadequate to describe the occurrence of a long-lived transient bimodality. The standard interpretation of the transient bimodality in terms of the ''flat'' region in the kinetic potential fails for the present case. An alternative analysis based on the effective potential of the Schrodinger-like Fokker-Planck equation is suggested. Our analysis of the transient bimodality is strongly supported by two examples that are numerically much more challenging than other examples that have been previously reported for this problem. C1 UNIV HOUSTON,DEPT PHYS,HOUSTON,TX 77204. IOWA STATE UNIV,DEPT CHEM,AMES,IA 50011. IOWA STATE UNIV,AMES LAB,AMES,IA 50011. RP Zhang, DS (reprint author), UNIV HOUSTON,DEPT CHEM,UNIV PK,HOUSTON,TX 77204, USA. RI Wei, Guowei /E-1852-2011 NR 28 TC 48 Z9 50 U1 0 U2 2 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 JUL PY 1997 VL 56 IS 1 BP 1197 EP 1206 DI 10.1103/PhysRevE.56.1197 PN B PG 10 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA XM377 UT WOS:A1997XM37700080 ER PT J AU Constable, S Roberts, JJ AF Constable, S Roberts, JJ TI Simultaneous modeling of thermopower and electrical conduction in olivine SO PHYSICS AND CHEMISTRY OF MINERALS LA English DT Article ID OXYGEN FUGACITY; TEMPERATURE; DUNITE AB Measurements of conductivity and thermopower as a function of oxygen fugacity (f(O2)) are used to derive a model for conduction in olivine. Thermopower at 1000-1200 degrees C is between 50 and 400 mu V/K and has a positive f(O2) dependence, and electrical conductivity exhibits approximately a 1/11 power dependence on f(O2). However, small polarons, considered to be the conducting defect in olivine at these temperatures, would produce a larger thermopower than observed, with a negative f(O2) dependence, as well as 1/6 power dependence of conductivity on f(O2) At least one other conducting defect species must be invoked to explain the observed magnitude and f(O2) dependence of thermopower. An electron/polaron model cannot be made to fit the conductivity and thermopower data well, but a polaron/magnesium vacancy model fits the data if a constant polaron or magnesium vacancy term is included. Concentrations from our fits are consistent with predictions from theoretical models, and our analysis predicts a transition from polaron dominance in conduction to magnesium vacancy dominance at around 1300 degrees C, as has been previously inferred from other data. C1 LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94551 USA. RP Constable, S (reprint author), UNIV CALIF SAN DIEGO, DEPT GEOPHYS & PLANETARY PHYS, LA JOLLA, CA 92093 USA. RI Constable, Steven/B-8959-2008 NR 25 TC 25 Z9 26 U1 1 U2 9 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0342-1791 J9 PHYS CHEM MINER JI Phys. Chem. Miner. PD JUL PY 1997 VL 24 IS 5 BP 319 EP 325 DI 10.1007/s002690050044 PG 7 WC Materials Science, Multidisciplinary; Mineralogy SC Materials Science; Mineralogy GA XP341 UT WOS:A1997XP34100001 ER PT J AU Ghosal, S Rose, HA AF Ghosal, S Rose, HA TI Two-dimensional plasma flow past a laser beam SO PHYSICS OF PLASMAS LA English DT Article ID FILAMENTATION AB Analytical results are presented for laser beam deflection rate due to plasma flow when the ponderomotive force (PMF) is static and given. Explicit expressions are obtained in various parameter regimes including that of weak PMF for the case of a coherent (diffraction limited) beam and a beam whose fluctuations are spatially homogeneous, as in the case of a model random phase plate beam. When the Landau damping coefficient, gamma(0), is negligible and the beam is either coherent and cylindrically symmetric, or random with isotropic fluctuations, the deflection rate is obtained as a closed form function of plasma flow Mach number, M. For finite damping, results are expressed in terms of a universal, one dimensional integral parameterized by M and gamma(0). For arbitrary PMF and M small, the problem is identified with one in the theory of random dielectric media. (C) 1997 American Institute of Physics. C1 LOS ALAMOS NATL LAB,DIV THEORY,LOS ALAMOS,NM 87545. RP Ghosal, S (reprint author), LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES,LOS ALAMOS,NM 87545, USA. RI Ghosal, Sandip/A-3534-2009; Ghosal, Sandip/B-7595-2009 OI Ghosal, Sandip/0000-0001-6587-3716; NR 21 TC 13 Z9 13 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD JUL PY 1997 VL 4 IS 7 BP 2376 EP 2396 DI 10.1063/1.872219 PG 21 WC Physics, Fluids & Plasmas SC Physics GA XH863 UT WOS:A1997XH86300010 ER PT J AU Winske, D AF Winske, D TI The magnetized Rayleigh-Taylor instability with a temporally variable gravity SO PHYSICS OF PLASMAS LA English DT Article ID SIMULATIONS; MAGNETOPAUSE AB Hybrid simulations with kinetic ions and massless fluid electrons are used to investigate the linear and nonlinear behavior of the Rayleigh-Taylor instability in a collisionless, magnetized plasma in slab geometry with the plasma subject to a time varying gravity. In particular, cases where the sign of gravity is reversed for some time interval are compared with the corresponding case with constant gravity. Consistent with simple theory, the effect of the gravity reversal is to stop the growth of the instability. And when the gravity is restored to its initial direction, the instability resumes at a rate that is commensurate with its earlier value. Several ways to estimate the rate of growth of the thickness of the mixing layer when (g) over right arrow is not constant are suggested and compared with the simulations. (C) 1997 American Institute of Physics. RP Winske, D (reprint author), LOS ALAMOS NATL LAB,PLASMA PHYS APPLICAT GRP,APPL THEORET & COMPUTAT PHYS DIV,LOS ALAMOS,NM 87545, USA. NR 23 TC 6 Z9 6 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD JUL PY 1997 VL 4 IS 7 BP 2454 EP 2463 DI 10.1063/1.872226 PG 10 WC Physics, Fluids & Plasmas SC Physics GA XH863 UT WOS:A1997XH86300017 ER PT J AU Waltz, RE Staebler, GM Dorland, W Hammett, GW Kotschenreuther, M Konings, JA AF Waltz, RE Staebler, GM Dorland, W Hammett, GW Kotschenreuther, M Konings, JA TI A gyro-Landau-fluid transport model SO PHYSICS OF PLASMAS LA English DT Article ID ENERGY CONFINEMENT; SIMULATIONS; TURBULENCE; TOKAMAKS AB A physically comprehensive and theoretically based transport model tuned to three-dimensional (3-D) ballooning mode gyrokinetic instabilities and gyrofluid nonlinear turbulence simulations is formulated with global and local magnetic shear stabilization and E x B rotational shear stabilization. Taking no fit coefficients from experiment, the model is tested against a large transport profile database with good agreement. This model is capable of describing enhanced core confinement transport barriers in negative central shear discharges based on rotational shear stabilization. The model is used to make ignition projections from relative gyroradius scaling discharges. (C) 1997 American Institute of Physics. C1 PRINCETON PLASMA PHYS LAB,PRINCETON,NJ 08543. FOM,AMSTERDAM,NETHERLANDS. RP Waltz, RE (reprint author), GEN ATOM CO,POB 85608,SAN DIEGO,CA 92186, USA. RI Hammett, Gregory/D-1365-2011; Dorland, William/B-4403-2009 OI Hammett, Gregory/0000-0003-1495-6647; Dorland, William/0000-0003-2915-724X NR 31 TC 383 Z9 384 U1 2 U2 28 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD JUL PY 1997 VL 4 IS 7 BP 2482 EP 2496 DI 10.1063/1.872228 PG 15 WC Physics, Fluids & Plasmas SC Physics GA XH863 UT WOS:A1997XH86300019 ER PT J AU Uhm, HS Hendricks, KJ Arman, MJ Bowers, L Hackett, KE Spencer, TA Coleman, PD Lemke, RW AF Uhm, HS Hendricks, KJ Arman, MJ Bowers, L Hackett, KE Spencer, TA Coleman, PD Lemke, RW TI A nonlinear theory of relativistic klystrons connected to a coaxial waveguide SO PHYSICS OF PLASMAS LA English DT Article ID ELECTRON-BEAM AB A self-consistent nonlinear theory of current modulation in an electron beam propagating through relativistic klystrons connected to a coaxial waveguide is developed. A theoretical model of the beam-energy increase Delta gamma near the extraction cavity is also developed, based on the self-potential depression. The potential depression kappa can be significantly reduced in the vicinity of the extraction cavity from its value at the injection point. In appropriate system parameters, the kinetic-energy increase can easily be more than 50 keV, thereby eliminating the possibility of virtual cathode in the extraction cavity. Properties of the current modulation in a klystron are also investigated, assuming that a regular cylindrical waveguide is connected to a coaxial waveguide at the propagation distance z = z(1). Due to proximity of a grounded conductor, the beam's potential depression kappa in the coaxial region is considerably less than that in the regular region. It is shown in the present analysis that amplitude of the current modulation increases drastically as the coaxial inner-conductor approaches the driving cavity. Moreover, the-amplitude of the current modulation in the coaxial region changes slowly in comparison with that in the regular region. C1 USAF,PHILLIPS LAB,KIRTLAND AFB,NM 87117. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP Uhm, HS (reprint author), USN,CTR SURFACE WARFARE,CARDEROCK DIV,9500 MACARTHUR BLVD,BETHESDA,MD 20817, USA. NR 5 TC 1 Z9 1 U1 1 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD JUL PY 1997 VL 4 IS 7 BP 2691 EP 2696 DI 10.1063/1.872355 PG 6 WC Physics, Fluids & Plasmas SC Physics GA XH863 UT WOS:A1997XH86300039 ER PT J AU Murillo, MS AF Murillo, MS TI Dynamic plasma screening effects on semiclassical inelastic electron-ion collisions in dense plasmas - Comment SO PHYSICS OF PLASMAS LA English DT Article ID NONIDEAL HYDROGEN PLASMA; RECOMBINATION; IONIZATION; COEFFICIENTS RP LOS ALAMOS NATL LAB, DIV THEORET, LOS ALAMOS, NM 87545 USA. NR 18 TC 1 Z9 1 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 1070-664X EI 1089-7674 J9 PHYS PLASMAS JI Phys. Plasmas PD JUL PY 1997 VL 4 IS 7 BP 2770 EP 2771 DI 10.1063/1.872400 PG 2 WC Physics, Fluids & Plasmas SC Physics GA XH863 UT WOS:A1997XH86300053 ER PT J AU Butler, J Quarrie, D AF Butler, J Quarrie, D TI CESR should be praised, not buried - Reply SO PHYSICS TODAY LA English DT Letter C1 LAWRENCE BERKELEY LAB,BERKELEY,CA. RP Butler, J (reprint author), FERMILAB NATL ACCELERATOR LAB,POB 500,BATAVIA,IL 60510, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 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 JUL PY 1997 VL 50 IS 7 BP 13 EP 13 PG 1 WC Physics, Multidisciplinary SC Physics GA XG698 UT WOS:A1997XG69800004 ER PT J AU Windsor, ML Zeevaart, JAD AF Windsor, ML Zeevaart, JAD TI Induction of ABA 8'-hydroxylase by (+)-S-,(-)-R- and 8',8',8'-trifluoro-S-abscisic acid in suspension cultures of potato and Arabidopsis SO PHYTOCHEMISTRY LA English DT Article DE Arabidopsis thaliana; Solanum tuberosum; potato; ABA 8'-hydroxylase; abscisic acid; phaseic acid ID ABSCISIC-ACID; MOLECULAR-OXYGEN; PHASEIC ACID; METHYL-ESTER; METABOLISM; CELLS; FRAGMENTATION; IONIZATION AB Suspension cultures of potato and Arabidopsis were incubated with 50 mu M of (+)-ABA and (-)-ABA for 3 hr. These pretreatments were found to increase the rate, by two- to seven-fold, of formation of [H-2(6)] phaseic acid (PA) from [H-2(6)] ABA, applied in a subsequent incubation. Pretreatment with trifluoro-ABA had a higher efficacy, increasing the rate of conversion 15-fold. Suspension culture cells that had been dehydrated and then rehydrated in the presence of [H-2(6)] ABA displayed a much lower enhancement of PA formation. We conclude that ABA induces its own oxidative catabolism in suspension cultures. (C) 1997 Elsevier Science Ltd. All rights reserved. C1 MICHIGAN STATE UNIV,DOE,PLANT RES LAB,E LANSING,MI 48824. FU NCRR NIH HHS [RR-00480] NR 20 TC 19 Z9 21 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0031-9422 J9 PHYTOCHEMISTRY JI Phytochemistry PD JUL PY 1997 VL 45 IS 5 BP 931 EP 934 DI 10.1016/S0031-9422(97)00022-8 PG 4 WC Biochemistry & Molecular Biology; Plant Sciences SC Biochemistry & Molecular Biology; Plant Sciences GA XG658 UT WOS:A1997XG65800012 PM 9214776 ER PT J AU Ladha, JK deBruijn, FJ Malik, KA AF Ladha, JK deBruijn, FJ Malik, KA TI Introduction: Assessing opportunities for nitrogen fixation in rice - a frontier project SO PLANT AND SOIL LA English DT Editorial Material DE endophyte; legume-Rhizobium; nif gene; nitrogen fixation; rice AB Recent advances in understanding symbiotic Rhizobium-legume interactions at the molecular level, the discovery of endophytic interactions of nitrogen-fixing organisms with non-legumes, and the ability to introduce genes into rice by transformation have stimulated researchers world wide to harness opportunities for nitrogen fixation and improved N nutrition in rice. In a think-tank workshop organized by IRRT in 1992, the participants reaffirmed that such opportunities do exist for cereals and recommended that rice be used as a model system. Subsequently, IRRI developed a New Frontier Project to coordinate the worldwide collaborative efforts among research centers committed to reducing dependency of rice on mineral N resources. An international Biological Nitrogen Fixation (BNF) working group was established to review, share research results/materials and to catalyze research. The strategies-of enabling rice to fix its own N are complex and of a long-term nature. However, if achieved, they could enhance rice productivity, resource conservation, and environmental security. The rate of obtaining success would, of course, benefit tremendously from concerted efforts from a critical mass of committed scientists around the world, as well as a constant and continued funding support from the ''donor'' community. C1 MICHIGAN STATE UNIV, DOE, PLANT RES LAB, E LANSING, MI USA. NATL INST BIOTECHNOL & GENET ENGN, FAISALABAD, PAKISTAN. RP Ladha, JK (reprint author), INT RICE RES INST, POB 933, MANILA 1099, PHILIPPINES. NR 24 TC 54 Z9 62 U1 1 U2 4 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0032-079X J9 PLANT SOIL JI Plant Soil PD JUL PY 1997 VL 194 IS 1-2 BP 1 EP 10 DI 10.1023/A:1004264423436 PG 10 WC Agronomy; Plant Sciences; Soil Science SC Agriculture; Plant Sciences GA YE296 UT WOS:A1997YE29600002 ER PT J AU Stoltzfus, JR So, R Malarvithi, PP Ladha, JK deBruijn, FJ AF Stoltzfus, JR So, R Malarvithi, PP Ladha, JK deBruijn, FJ TI Isolation of endophytic bacteria from rice and assessment of their potential for supplying rice with biologically fixed nitrogen SO PLANT AND SOIL LA English DT Article; Proceedings Paper CT Meeting on Opportunities for Biological Nitrogen Fixation in Rice and Other Non-Legumes CY OCT 13-15, 1996 CL NATL INST BIOTECHNOL & GENET ENGN, FALSALABAD, PAKISTAN SP Frontier Project Nitrogen Fixat Rice, 2nd Working Grp HO NATL INST BIOTECHNOL & GENET ENGN DE endophytic microbes; endo-symbiosis; genomic fingerprinting; infection; marker genes; nitrogen fixation; PCR; rep-PCR; rice ID MOLECULAR EVOLUTIONARY ANALYSIS; SUSTAINABLE AGRICULTURE; N-2-FIXING BACTERIA; NIFH GENE; FIXATION; ROOTS; RHIZOSPHERE; EXPRESSION; RHIZOBIUM; ORGANISMS AB The extension of nitrogen-fixing symbioses to important crop plants such as the cereals has been a long-standing goal in the field of biological nitrogen fixation. One of the approaches that has been used to try to achieve this goal involves the isolation and characterization of stable endophytic bacteria from a variety of wild and cultivated rice species that either have a natural ability. to fix nitrogen or can be engineered to do so. Here we present the results of our first screening effort for rice endophytes and their characterization using acetylene reduction assays (ARA), genomic fingerprinting with primers corresponding to naturally occurring repetitive DNA elements (rep-PCR), partial 16S rDNA sequence analysis and PCR mediated detection of nitrogen fixation (nif) genes with universal nif primers developed in our laboratory. We also describe our efforts to inoculate rice plants with the isolates obtained from the screening, in order to examine their invasiveness and persistence (stable endophytic maintenance). Lastly, we review our attempts to tag selected isolates with reporter genes/proteins, such as beta-glucuronidase (gus) or green fluorescent protein (gfp), in order to be able to track putative endophytes during colonization of rice tissues. C1 MICHIGAN STATE UNIV,DOE,PLANT RES LAB,E LANSING,MI 48824. MICHIGAN STATE UNIV,DEPT MICROBIOL,E LANSING,MI 48824. MICHIGAN STATE UNIV,NSF CTR MICROBIAL ECOL,E LANSING,MI 48824. INT RICE RES INST,LOS BANOS,PHILIPPINES. NR 48 TC 114 Z9 130 U1 4 U2 33 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0032-079X J9 PLANT SOIL JI Plant Soil PD JUL PY 1997 VL 194 IS 1-2 BP 25 EP 36 DI 10.1023/A:1004298921641 PG 12 WC Agronomy; Plant Sciences; Soil Science SC Agriculture; Plant Sciences GA YE296 UT WOS:A1997YE29600005 ER PT J AU Reddy, PM Ladha, JK So, RB Hernandez, RJ Ramos, MC Angeles, OR Dazzo, FB deBruijn, FJ AF Reddy, PM Ladha, JK So, RB Hernandez, RJ Ramos, MC Angeles, OR Dazzo, FB deBruijn, FJ TI Rhizobial communication with rice roots: Induction of phenotypic changes, mode of invasion and extent of colonization SO PLANT AND SOIL LA English DT Article; Proceedings Paper CT Meeting on Opportunities for Biological Nitrogen Fixation in Rice and Other Non-Legumes CY OCT 13-15, 1996 CL NATL INST BIOTECHNOL & GENET ENGN, FALSALABAD, PAKISTAN SP Frontier Project Nitrogen Fixat Rice, 2nd Working Grp HO NATL INST BIOTECHNOL & GENET ENGN DE colonization; indole-3-acetic acid; invasion; Nod factors; nod gene induction; rhizobia,; rhizobial attachment; rice; thick short lateral roots; trans-zeatin ID LEGUMINOSARUM BIOVAR TRIFOLII; ARBUSCULAR MYCORRHIZAL FUNGI; NODULIN GENE SRENOD2; SESBANIA-ROSTRATA; NODULATION GENES; AZORHIZOBIUM-CAULINODANS; BRADYRHIZOBIUM-ELKANII; DEVELOPMENTAL BIOLOGY; WHITE CLOVER; MELILOTI AB Legume-rhizobial interactions culminate in the formation of structures known as nodules. In this specialized niche, rhizobia are insulated from microbial competition and fix nitrogen which becomes directly available to the legume plant. It has been a long-standing goal in the field of biological nitrogen fixation to extend the nitrogen-fixing symbiosis to non-nodulated cereal plants, such as rice. To achieve this goal, extensive knowledge of the legume-rhizobia symbioses should help in formulating strategies for developing potential rice-rhizobia symbioses or endophytic interactions. As a first step to assess opportunities for developing a rice-rhizobia symbiosis, we evaluated certain aspects of rice-rhizobia associations to determine the extent of predisposition of rice roots for forming an intimate association with rhizobia. Our studies indicate that: a. Rice root exudates do not activate the expression of nodulation genes such as nodY of Bradyrhizobium japonicum USDA110, nodA of R. leguminosarum by. trifolii, or nodSU of Rhizobium. sp. NGR234; b. Neither viable wild-type rhizobia, nor purified chitolipooligosaccharide (CLOS) Nod factors elicit root hair deformation or true nodule formation in rice; c. Rhizobia-produced indole-3-acetic acid, but neither trans-zeatin nor CLOS Nod factors, seem to promote the formation of thick, short lateral roots in rice; d. Rhizobia develop neither the symbiont-specific pattern of root hair attachment nor extensive cellulose microfibril production on the rice root epidermis; e. A primary mode of rhizobial invasion of rice roots is through cracks in the epidermis and fissures created during emergence of lateral roots; f. This infection process is nod-gene independent, nonspecific, and does not involve the formation of infection threads; g. Endophytic colonization observed so far is restricted to intercellular spaces or within host cells undergoing lysis. h. The cortical sclerenchymatous layer containing tightly packed, thick wailed fibers appears to be a significant barrier that restricts rhizobial invasion into deeper layers of the root cortex. Therefore, we conclude that the molecular and cell biology of the Rhizobium-rice association differs in many respects from the biology underlying the development of root nodules in the Rhizobium-legume symbiosis. C1 INT RICE RES INST,MANILA 1099,PHILIPPINES. MICHIGAN STATE UNIV,DOE,PLANT RES LAB,E LANSING,MI 48824. NR 70 TC 63 Z9 66 U1 0 U2 23 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0032-079X J9 PLANT SOIL JI Plant Soil PD JUL PY 1997 VL 194 IS 1-2 BP 81 EP 98 DI 10.1023/A:1004243915997 PG 18 WC Agronomy; Plant Sciences; Soil Science SC Agriculture; Plant Sciences GA YE296 UT WOS:A1997YE29600010 ER PT J AU Fischer, BU Frehner, M Hebeisen, T Zanetti, S Stadelmann, F Luscher, A Hartwig, UA Hendrey, GR Blum, H Nosberger, J AF Fischer, BU Frehner, M Hebeisen, T Zanetti, S Stadelmann, F Luscher, A Hartwig, UA Hendrey, GR Blum, H Nosberger, J TI Source-sink relations in Lolium perenne L. as reflected by carbohydrate concentrations in leaves and pseudo-stems during regrowth in a free air carbon dioxide enrichment (FACE) experiment SO PLANT CELL AND ENVIRONMENT LA English DT Article DE Lolium perenne L; Poaceae; defoliation; elevated carbon dioxide; perennial ryegrass; regrowth; sink limitation; source-sink relations; starch; water-soluble carbohydrates ID SIMULATED SEASONAL-CHANGES; ELEVATED CO2; TRIFOLIUM-REPENS; PASTURE TURVES; GROWTH; TEMPERATURE; PLANTS; LEAF; RESPIRATION; RYEGRASS AB The effect of an elevated partial pressure of CO2 (P-CO2) on carbohydrate concentrations in source leaves and pseudostems (stubble) of Lolium perenne L., (perennial ryegrass) during regrowth was studied in a regularly defoliated grass sward in the field, The free air carbon dioxide enrichment (FACE) technology enabled natural environmental conditions to be provided, Two levels of nitrogen (N) supply were used to modulate potential plant growth. Carbohydrate concentrations in source leaves were increased at elevated P-CO2, particularly at low N supply, Elevated leaf carbohydrate concentrations were related to an increased structural carbon (C) to N ratio and thus reflected an increased C availability together with a N-dependent sink limitation, Immediately after defoliation, apparent assimilate export rates (differences in the carbohydrate concentrations of young source leaves measured in the evening and on the following morning) showed a greater increase at elevated p(CO2) than at ambient p(CO2); however, replenishment of carbohydrate reserves was not accelerated Distinct, treatment-dependent carbohydrate concentrations in pseudo-stems suggested an increasing degree of C-sink limitation from the treatment at ambient p(CO2) with high N supply to that at elevated P-CO2 With low N supply. During two growing seasons, no evidence of a substantial change in the response of the carbohydrate source in L. perenne to elevated p(CO2) was found, Our results support the view that the response of L. perenne to elevated p(CO2) is restricted by a C-sink limitation, which is particularly severe at low N supply. C1 ETH ZURICH,INST PLANT SCI,CH-8092 ZURICH,SWITZERLAND. BROOKHAVEN NATL LAB,DEPT APPL SCI,UPTON,NY 11973. NR 35 TC 60 Z9 63 U1 0 U2 19 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0NE SN 0140-7791 J9 PLANT CELL ENVIRON JI Plant Cell Environ. PD JUL PY 1997 VL 20 IS 7 BP 945 EP 952 DI 10.1046/j.1365-3040.1997.d01-131.x PG 8 WC Plant Sciences SC Plant Sciences GA XK285 UT WOS:A1997XK28500009 ER PT J AU Pinder, JE Kroh, GC White, JD May, AMB AF Pinder, JE Kroh, GC White, JD May, AMB TI The relationships between vegetation type and topography in Lassen volcanic national park SO PLANT ECOLOGY LA English DT Article DE aspect; chaparral; conifer; elevation; slope; TRMI ID FOREST ENVIRONMENT RELATIONSHIPS; CALIFORNIA AB The relationships between topographic features and the relative abundances of vegetation types were analyzed for the mid-montane conifer forests, the upper montane conifer forests and the alpine areas of Lassen Volcanic National Park in the Cascade Range of northern California using Landsat Thematic Mapper data. Vegetation types were identified from Landsat Thematic Mapper data and included pine, fir, montane chaparral, willow/alder and herbaceous communities. Topographic features including aspect, slope steepness, slope configuration (i.e., convex, straight or concave) and slope position (i.e., ridge top to valley bottom) were computed from USGS Digital Elevation Models. The distribution of montane chaparral was consistent with its dependency on fire with chaparral communities being more abundant on more xeric aspects and on steeper and more xeric slope configurations. Slope position was important in determining the distribution of willow/alder communities which were more abundant in valley bottom locations. Both slope steepness and slope position affected the abundance of herbaceous communities. Herbaceous communities were: (1) more prevalent on steeper slopes due to the distribution of dicotyledonous forb species; and (2) more abundant in valley bottoms due to the distribution of monocotyledonous species in wet meadows. Pines and firs were separated along a gradient of slope steepness with the firs being more abundant on steep slopes and the pines being more abundant on shallow slopes. In the alpine areas above 2350 m, the abundance of most vegetation types declined with increasingly mesic aspects. This decline may be related to the prolonged persistence of snow in areas of less intense solar radiation. C1 SAVANNAH RIVER ECOL LAB,AIKEN,SC 29802. TEXAS CHRISTIAN UNIV,DEPT BIOL,FT WORTH,TX 76129. NR 29 TC 29 Z9 60 U1 4 U2 15 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 1385-0237 J9 PLANT ECOL JI Plant Ecol. PD JUL PY 1997 VL 131 IS 1 BP 17 EP 29 DI 10.1023/A:1009792123571 PG 13 WC Plant Sciences; Ecology; Forestry SC Plant Sciences; Environmental Sciences & Ecology; Forestry GA XL830 UT WOS:A1997XL83000003 ER PT J AU Gil, P Green, PJ AF Gil, P Green, PJ TI Regulatory activity exerted by the SAUR-AC1 promoter region in transgenic plants SO PLANT MOLECULAR BIOLOGY LA English DT Article ID PROTEIN-SYNTHESIS INHIBITORS; ARABIDOPSIS-THALIANA; MESSENGER-RNAS; AUXIN; EXPRESSION; TISSUE; TRANSCRIPTS; INDUCTION AB SAUR-ACl is a small-auxin-up-RNA (SAUR) gene of Arabidopsis. Here we demonstrate that the SAUR-ACl promoter region induces accumulation of a reporter transcript upon treatment with auxin and is preferentially active in elongating hypocotyls and certain other organs and tissues of transgenic Arabidopsis and tobacco plants. This study extends the utility of the SAUR-ACl gene by providing a foundation for comparative analyses of SAUR promoter activity in auxin-responsive mutants of Arabidopsis. C1 MICHIGAN STATE UNIV,US DOE,PLANT RES LAB,E LANSING,MI 48824. NR 20 TC 23 Z9 27 U1 0 U2 2 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0167-4412 J9 PLANT MOL BIOL JI Plant Mol.Biol. PD JUL PY 1997 VL 34 IS 5 BP 803 EP 808 DI 10.1023/A:1005875300606 PG 6 WC Biochemistry & Molecular Biology; Plant Sciences SC Biochemistry & Molecular Biology; Plant Sciences GA XR962 UT WOS:A1997XR96200009 PM 9278170 ER PT J AU Morgan, RM Ivanov, AG Priscu, JC Maxwell, DP Huner, NPA AF Morgan, RM Ivanov, AG Priscu, JC Maxwell, DP Huner, NPA TI Chlorophyll a/b proteins of photosystem I in the psychrophyllic alga, Chlamydomonas subcaudata SO PLANT PHYSIOLOGY LA English DT Meeting Abstract C1 UNIV WESTERN ONTARIO,DEPT PLANT SCI,LONDON,ON N6A 5B7,CANADA. MONTANA STATE UNIV,DEPT BIOL,BOZEMAN,MT 59717. MICHIGAN STATE UNIV,MSU DOE,PLANT RES LAB,E LANSING,MI 48824. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC PLANT PHYSIOLOGISTS PI ROCKVILLE PA 15501 MONONA DRIVE, ROCKVILLE, MD 20855 SN 0032-0889 J9 PLANT PHYSIOL JI Plant Physiol. PD JUL PY 1997 VL 114 IS 3 SU S BP 91 EP 91 PG 1 WC Plant Sciences SC Plant Sciences GA XL119 UT WOS:A1997XL11900135 ER PT J AU Yu, JP Jung, YS Vassiliev, I Golbeck, J McIntosh, L AF Yu, JP Jung, YS Vassiliev, I Golbeck, J McIntosh, L TI Mutations affecting both assembly and function of photosystem I SO PLANT PHYSIOLOGY LA English DT Meeting Abstract C1 MICHIGAN STATE UNIV,MSU DOE,PLANT RES LAB,E LANSING,MI 48824. PENN STATE UNIV,DEPT BIOCHEM & MOL BIOL,STATE COLL,PA 16802. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC PLANT PHYSIOLOGISTS PI ROCKVILLE PA 15501 MONONA DRIVE, ROCKVILLE, MD 20855 SN 0032-0889 J9 PLANT PHYSIOL JI Plant Physiol. PD JUL PY 1997 VL 114 IS 3 SU S BP 96 EP 96 PG 1 WC Plant Sciences SC Plant Sciences GA XL119 UT WOS:A1997XL11900140 ER PT J AU Anderson, LE Li, AD Lateef, SS Stevens, FJ AF Anderson, LE Li, AD Lateef, SS Stevens, FJ TI Potential inter-domain disulfides in three higher plant mitochondrial citrate synthases. SO PLANT PHYSIOLOGY LA English DT Meeting Abstract C1 UNIV ILLINOIS,CHICAGO,IL. ARGONNE NATL LAB,ARGONNE,IL 60439. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC PLANT PHYSIOLOGISTS PI ROCKVILLE PA 15501 MONONA DRIVE, ROCKVILLE, MD 20855 SN 0032-0889 J9 PLANT PHYSIOL JI Plant Physiol. PD JUL PY 1997 VL 114 IS 3 SU S BP 152 EP 152 PG 1 WC Plant Sciences SC Plant Sciences GA XL119 UT WOS:A1997XL11900196 ER PT J AU Takahashi, K Kim, CY Webster, C AF Takahashi, K Kim, CY Webster, C TI Binding specificity of initiation factor eIFiso4F for oligonucleotides. SO PLANT PHYSIOLOGY LA English DT Meeting Abstract C1 UNIV CALIF RIVERSIDE,DEPT BIOCHEM,RIVERSIDE,CA 92521. LOS ALAMOS NATL LAB,MSM888,LOS ALAMOS,NM 87545. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER SOC PLANT PHYSIOLOGISTS PI ROCKVILLE PA 15501 MONONA DRIVE, ROCKVILLE, MD 20855 SN 0032-0889 J9 PLANT PHYSIOL JI Plant Physiol. PD JUL PY 1997 VL 114 IS 3 SU S BP 237 EP 237 PG 1 WC Plant Sciences SC Plant Sciences GA XL119 UT WOS:A1997XL11900281 ER PT J AU HeesePeck, A Raikhel, NV AF HeesePeck, A Raikhel, NV TI Nuclear pore complex proteins in higher plants. SO PLANT PHYSIOLOGY LA English DT Meeting Abstract C1 MICHIGAN STATE UNIV,US DOE,PLANT RES LAB,E LANSING,MI 48824. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC PLANT PHYSIOLOGISTS PI ROCKVILLE PA 15501 MONONA DRIVE, ROCKVILLE, MD 20855 SN 0032-0889 J9 PLANT PHYSIOL JI Plant Physiol. PD JUL PY 1997 VL 114 IS 3 SU S BP 260 EP 260 PG 2 WC Plant Sciences SC Plant Sciences GA XL119 UT WOS:A1997XL11900304 ER PT J AU Gebre, GM Tschaplinski, TJ Shirshac, TL AF Gebre, GM Tschaplinski, TJ Shirshac, TL TI Species and treatment differences in osmotic potential and solute accumulation of several hardwoods in a throughfall manipulation of an upland oak forest. SO PLANT PHYSIOLOGY LA English DT Meeting Abstract C1 OAK RIDGE NATL LAB,OAK RIDGE,TN. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC PLANT PHYSIOLOGISTS PI ROCKVILLE PA 15501 MONONA DRIVE, ROCKVILLE, MD 20855 SN 0032-0889 J9 PLANT PHYSIOL JI Plant Physiol. PD JUL PY 1997 VL 114 IS 3 SU S BP 367 EP 367 PG 1 WC Plant Sciences SC Plant Sciences GA XL119 UT WOS:A1997XL11900409 ER PT J AU Edwards, NT Wang, YC Tschaplinski, TJ Hanson, PJ AF Edwards, NT Wang, YC Tschaplinski, TJ Hanson, PJ TI Stem respiration, water relations and leaf phenology responses in Acer rubrum L to soil moisture status in a mature upland oak forest in Tennessee. SO PLANT PHYSIOLOGY LA English DT Meeting Abstract C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RI Hanson, Paul J./D-8069-2011 OI Hanson, Paul J./0000-0001-7293-3561 NR 0 TC 0 Z9 0 U1 1 U2 4 PU AMER SOC PLANT PHYSIOLOGISTS PI ROCKVILLE PA 15501 MONONA DRIVE, ROCKVILLE, MD 20855 SN 0032-0889 J9 PLANT PHYSIOL JI Plant Physiol. PD JUL PY 1997 VL 114 IS 3 SU S BP 468 EP 468 PG 2 WC Plant Sciences SC Plant Sciences GA XL119 UT WOS:A1997XL11900508 ER PT J AU Geck, MK Hartman, FC AF Geck, MK Hartman, FC TI Interactions of chloroplastic thioredoxins with target enzymes. SO PLANT PHYSIOLOGY LA English DT Meeting Abstract C1 UNIV TENNESSEE,GRAD SCH BIOMED SCI,OAK RIDGE,TN 37831. OAK RIDGE NATL LAB,DIV LIFE SCI,PROT ENGN PROGRAM,OAK RIDGE,TN 37831. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC PLANT PHYSIOLOGISTS PI ROCKVILLE PA 15501 MONONA DRIVE, ROCKVILLE, MD 20855 SN 0032-0889 J9 PLANT PHYSIOL JI Plant Physiol. PD JUL PY 1997 VL 114 IS 3 SU S BP 655 EP 655 PG 1 WC Plant Sciences SC Plant Sciences GA XL119 UT WOS:A1997XL11900692 ER PT J AU vanderKnapp, E Jagoueix, S Kende, H AF vanderKnapp, E Jagoueix, S Kende, H TI Expression of a DNA replication factor is induced by gibberellin in deepwater rice. SO PLANT PHYSIOLOGY LA English DT Meeting Abstract C1 MICHIGAN STATE UNIV,DOE PLANT RES LAB,E LANSING,MI 48824. INRA,CTR RECH BORDEAUX,VILLENAVE DORNON,FRANCE. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER SOC PLANT PHYSIOLOGISTS PI ROCKVILLE PA 15501 MONONA DRIVE, ROCKVILLE, MD 20855 SN 0032-0889 J9 PLANT PHYSIOL JI Plant Physiol. PD JUL PY 1997 VL 114 IS 3 SU S BP 774 EP 774 PG 1 WC Plant Sciences SC Plant Sciences GA XL119 UT WOS:A1997XL11900809 ER PT J AU Xu, YL Zeevaart, JAD AF Xu, YL Zeevaart, JAD TI Negative feedback loop of GA5 expression constitutes part of the mechanism of stem height regulation in Arabidopsis thaliana. SO PLANT PHYSIOLOGY LA English DT Meeting Abstract C1 MICHIGAN STATE UNIV,DOE PLANT RES LAB,E LANSING,MI 48824. NR 0 TC 0 Z9 0 U1 1 U2 3 PU AMER SOC PLANT PHYSIOLOGISTS PI ROCKVILLE PA 15501 MONONA DRIVE, ROCKVILLE, MD 20855 SN 0032-0889 J9 PLANT PHYSIOL JI Plant Physiol. PD JUL PY 1997 VL 114 IS 3 SU S BP 789 EP 789 PG 1 WC Plant Sciences SC Plant Sciences GA XL119 UT WOS:A1997XL11900824 ER PT J AU Schwartz, SH Tan, BC Gage, DA Zeevaart, JAD McCarty, DR AF Schwartz, SH Tan, BC Gage, DA Zeevaart, JAD McCarty, DR TI VP14 of maize catalyzes the carotenoid cleavage reaction of abscisic acid biosynthesis. SO PLANT PHYSIOLOGY LA English DT Meeting Abstract C1 MICHIGAN STATE UNIV,DOE PLANT RES LAB,E LANSING,MI 48824. UNIV FLORIDA,PMCB GRAD PROGRAM,GAINESVILLE,FL 32611. MICHIGAN STATE UNIV,DEPT BIOCHEM,E LANSING,MI 48824. NR 0 TC 1 Z9 1 U1 0 U2 5 PU AMER SOC PLANT PHYSIOLOGISTS PI ROCKVILLE PA 15501 MONONA DRIVE, ROCKVILLE, MD 20855 SN 0032-0889 J9 PLANT PHYSIOL JI Plant Physiol. PD JUL PY 1997 VL 114 IS 3 SU S BP 798 EP 798 PG 2 WC Plant Sciences SC Plant Sciences GA XL119 UT WOS:A1997XL11900833 ER PT J AU Cho, HT Kende, H AF Cho, HT Kende, H TI Expression of expansin genes in rice is correlated with growth. SO PLANT PHYSIOLOGY LA English DT Meeting Abstract C1 MICHIGAN STATE UNIV,MSU DOE PLANT RES LAB,E LANSING,MI 48824. NR 0 TC 3 Z9 3 U1 0 U2 1 PU AMER SOC PLANT PHYSIOLOGISTS PI ROCKVILLE PA 15501 MONONA DRIVE, ROCKVILLE, MD 20855 SN 0032-0889 J9 PLANT PHYSIOL JI Plant Physiol. PD JUL PY 1997 VL 114 IS 3 SU S BP 810 EP 810 PG 1 WC Plant Sciences SC Plant Sciences GA XL119 UT WOS:A1997XL11900845 ER PT J AU Guy, RD Vanlerberghe, GC McIntosh, L AF Guy, RD Vanlerberghe, GC McIntosh, L TI Partitioning of electron transport during respiration in transgenic tobacco with modified levels of alternative oxidase protein. SO PLANT PHYSIOLOGY LA English DT Meeting Abstract C1 UNIV BRITISH COLUMBIA,DEPT FOREST SCI,VANCOUVER,BC V6T 1Z4,CANADA. UNIV TORONTO,DIV LIFE SCI,SCARBOROUGH,ON M1C 1A4,CANADA. MICHIGAN STATE UNIV,MSU DOE PLANT RES LAB,E LANSING,MI 48824. MICHIGAN STATE UNIV,DEPT BIOCHEM,E LANSING,MI 48824. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER SOC PLANT PHYSIOLOGISTS PI ROCKVILLE PA 15501 MONONA DRIVE, ROCKVILLE, MD 20855 SN 0032-0889 J9 PLANT PHYSIOL JI Plant Physiol. PD JUL PY 1997 VL 114 IS 3 SU S BP 1013 EP 1013 PG 1 WC Plant Sciences SC Plant Sciences GA XL119 UT WOS:A1997XL11901045 ER PT J AU Ghirardi, ML Seibert, M AF Ghirardi, ML Seibert, M TI Techniques for isolation of oxygen-tolerant mutants of hydrogen-producing Chlamydomonas reinhardtii. SO PLANT PHYSIOLOGY LA English DT Meeting Abstract C1 NREL,GOLDEN,CO 80401. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC PLANT PHYSIOLOGISTS PI ROCKVILLE PA 15501 MONONA DRIVE, ROCKVILLE, MD 20855 SN 0032-0889 J9 PLANT PHYSIOL JI Plant Physiol. PD JUL PY 1997 VL 114 IS 3 SU S BP 1027 EP 1027 PG 1 WC Plant Sciences SC Plant Sciences GA XL119 UT WOS:A1997XL11901059 ER PT J AU Savitch, LV Gray, GG Massacci, A Huner, NPA AF Savitch, LV Gray, GG Massacci, A Huner, NPA TI Mechanisms of cultivar dependent photosynthetic adjustment of Triticum aestivum L to high irradiance, cold stress and cold hardening. SO PLANT PHYSIOLOGY LA English DT Meeting Abstract C1 UNIV WESTERN ONTARIO,DEPT PLANT SCI,LONDON,ON N6A 5B7,CANADA. MICHIGAN STATE UNIV,DOE,PLANT RES LAB,E LANSING,MI. CNR,IST BIOCHIM & ECOFISIOL VEGETALI,ROME,ITALY. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC PLANT PHYSIOLOGISTS PI ROCKVILLE PA 15501 MONONA DRIVE, ROCKVILLE, MD 20855 SN 0032-0889 J9 PLANT PHYSIOL JI Plant Physiol. PD JUL PY 1997 VL 114 IS 3 SU S BP 1097 EP 1097 PG 2 WC Plant Sciences SC Plant Sciences GA XL119 UT WOS:A1997XL11901129 ER PT J AU Harnett, JP Durnford, DG RoobalBoza, M Green, BR AF Harnett, JP Durnford, DG RoobalBoza, M Green, BR TI Molecular organization of the Heterosigma fucoxanthin-Chl a/c light-harvesting apparatus: Is it as complex as the Chl a/b antenna system of higher plants? SO PLANT PHYSIOLOGY LA English DT Meeting Abstract C1 UNIV BRITISH COLUMBIA,DEPT BOT,VANCOUVER,BC,CANADA. BROOKHAVEN NATL LAB,UPTON,NY 11973. UNIV STOCKHOLM,DEPT BIOCHEM,S-10691 STOCKHOLM,SWEDEN. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER SOC PLANT PHYSIOLOGISTS PI ROCKVILLE PA 15501 MONONA DRIVE, ROCKVILLE, MD 20855 SN 0032-0889 J9 PLANT PHYSIOL JI Plant Physiol. PD JUL PY 1997 VL 114 IS 3 SU S BP 1110 EP 1110 PG 1 WC Plant Sciences SC Plant Sciences GA XL119 UT WOS:A1997XL11901142 ER PT J AU Venkataraman, S Raikhel, NV AF Venkataraman, S Raikhel, NV TI Isolation of Arabidopsis mutants with an altered vacuolar protein sorting machinery. SO PLANT PHYSIOLOGY LA English DT Meeting Abstract C1 MICHIGAN STATE UNIV,US DOE,PLANT RES LAB,E LANSING,MI 48824. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC PLANT PHYSIOLOGISTS PI ROCKVILLE PA 15501 MONONA DRIVE, ROCKVILLE, MD 20855 SN 0032-0889 J9 PLANT PHYSIOL JI Plant Physiol. PD JUL PY 1997 VL 114 IS 3 SU S BP 1208 EP 1208 PG 2 WC Plant Sciences SC Plant Sciences GA XL119 UT WOS:A1997XL11901239 ER PT J AU Dai, ZY Gao, JW Hooker, BS AF Dai, ZY Gao, JW Hooker, BS TI Expression of human coagulation factor VIII gene in tobacco. SO PLANT PHYSIOLOGY LA English DT Meeting Abstract C1 PACIFIC NW LAB, BIOPROC GRP, RICHLAND, WA 99352 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC PLANT PHYSIOLOGISTS PI ROCKVILLE PA 15501 MONONA DRIVE, ROCKVILLE, MD 20855 SN 0032-0889 J9 PLANT PHYSIOL JI Plant Physiol. PD JUL PY 1997 VL 114 IS 3 SU S BP 1584 EP 1584 PG 1 WC Plant Sciences SC Plant Sciences GA XL119 UT WOS:A1997XL11901611 ER PT J AU Peck, SC Pawlowski, K Kende, H AF Peck, SC Pawlowski, K Kende, H TI ACC oxidase mRNA is asymmetrically distributed in the apical hooks of etiolated pea seedlings. SO PLANT PHYSIOLOGY LA English DT Meeting Abstract C1 MICHIGAN STATE UNIV,MSU DOE PLANT RES LAB,E LANSING,MI 48824. AGR UNIV WAGENINGEN,DEPT MOL BIOL,NL-6703 HA WAGENINGEN,NETHERLANDS. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC PLANT PHYSIOLOGISTS PI ROCKVILLE PA 15501 MONONA DRIVE, ROCKVILLE, MD 20855 SN 0032-0889 J9 PLANT PHYSIOL JI Plant Physiol. PD JUL PY 1997 VL 114 IS 3 SU S BP 1623 EP 1623 PG 1 WC Plant Sciences SC Plant Sciences GA XL119 UT WOS:A1997XL11901650 ER PT J AU Mynick, HE AF Mynick, HE TI Neoclassical transport in quasi-axially symmetric stellarators SO PLASMA PHYSICS REPORTS LA English DT Article ID ELECTRIC-FIELD; CONFINEMENT AB We present a numerical and analytic assessment of the transport in two quasi-axially symmetric stellarators including one variant of the MHH2 class [1] of such devices, and a configuration we refer to as NHH2, closely related to MHH2. Monte Carlo simulation results are compared with expectations from established stellarator neoclassical theory and with some empirical stellarator scalings used as an estimate of the turbulent transport that might be expected. From the standpoint of transport, these may be viewed as either tokamaks with large (delta similar to 1%)but low-Il ripple, or as stellarators with small ripple. For NHH2, numerical results are reasonably well explained by analytic neoclassical theory. MHH2 adheres less to assumptions made in most analytic theory, and its numerical results agree less well with theory than those for NHH2. However, for both, the non-axisymmetric contribution to the heat flux is comparable with the symmetric neoclassical contribution, and also falls into the range of the experimental anomalous (turbulent) contribution. Thus, it appears, that effort to further optimize the thermal transport beyond the particular incarnation studied here would be of at most modest utility. However, the favorable thermal confinement relies heavily on the radial electric field. Thus, the present configuration will have a loss cone for trapped energetic ions, so that further optimization may be indicated for a large device of this type. RP Mynick, HE (reprint author), PRINCETON UNIV, PLASMA PHYS LAB, POB 451, PRINCETON, NJ 08543 USA. NR 16 TC 4 Z9 4 U1 0 U2 0 PU MAIK NAUKA/INTERPERIODICA PUBL PI WOODBURY PA C/O AMERICAN INST PHYSICS, 500 SUNNYSIDE BLVD, MEMBER SUBSCRIBER SERVICES, WOODBURY, NY 11797-2999 SN 1063-780X J9 PLASMA PHYS REP JI Plasma Phys. Rep. PD JUL PY 1997 VL 23 IS 7 BP 547 EP 554 PG 8 WC Physics, Fluids & Plasmas SC Physics GA XP020 UT WOS:A1997XP02000003 ER PT J AU Bonivert, WD Cushnie, G AF Bonivert, WD Cushnie, G TI NMFRC adds list serve SO PLATING AND SURFACE FINISHING LA English DT Editorial Material C1 CAI ENGN,OAKTON,VA 22124. RP Bonivert, WD (reprint author), SANDIA NATL LABS,M-S 9404,BOX 969,LIVERMORE,CA 94551, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER ELECTROPLATERS SOC INC PI ORLANDO PA 12644 RESEARCH PKWY, ORLANDO, FL 32826-3298 SN 0360-3164 J9 PLAT SURF FINISH JI Plat. Surf. Finish. PD JUL PY 1997 VL 84 IS 7 BP 46 EP 47 PG 2 WC Metallurgy & Metallurgical Engineering; Materials Science, Coatings & Films SC Metallurgy & Metallurgical Engineering; Materials Science GA XH818 UT WOS:A1997XH81800015 ER PT J AU Albalak, RJ Thomas, EL Capel, MS AF Albalak, RJ Thomas, EL Capel, MS TI Thermal annealing of roll-cast triblock copolymer films SO POLYMER LA English DT Article DE block copolymers; roll-casting; annealing ID BLOCK COPOLYMER; SHEAR; MORPHOLOGY; PHASES AB Polystyrene-polybutadiene-polystyrene triblock copolymers were roll-cast from toluene solutions to form globally oriented films. Microstructural changes following thermal annealing of films with cylindrical and lamellar morphology were monitored using two-dimensional small angle X-ray scattering, transmission electron microscopy and thermomechanical analysis. The microdomains in the unannealed films of cylindrical morphology were found to be assembled on a distorted hexagonal lattice, due to the roll-casting flow field. Thermal annealing significantly improved the alignment and packing of the cylinders, increased grain size, reduced the number of morphological defects and resulted in a 12% decrease in the area per junction. The microstructure of the unannealed films of lamellar morphology was observed to be composed of many small grains with low-angle helicoid surface twist boundaries. Annealing significantly reduced the number of grains and twist boundaries and resulted in a 7% decrease in the area per junction. Molecular models are presented for the relaxation of the chains during the annealing process in both cylindrical and lamellar morphologies based upon 2-D SAXS data and thermomechanical analysis. (C) 1997 Elsevier Science Ltd. C1 MIT,DEPT MAT SCI & ENGN,CAMBRIDGE,MA 02139. BROOKHAVEN NATL LAB,NATL SYNCHROTRON LIGHT SOURCE DEPT,UPTON,NY 11973. NR 15 TC 58 Z9 59 U1 0 U2 18 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0032-3861 J9 POLYMER JI Polymer PD JUL PY 1997 VL 38 IS 15 BP 3819 EP 3825 DI 10.1016/S0032-3861(96)00938-X PG 7 WC Polymer Science SC Polymer Science GA XH536 UT WOS:A1997XH53600012 ER PT J AU Campbell, IH Ferraris, JP Hagler, TW Joswick, MD Parker, ID Smith, DL AF Campbell, IH Ferraris, JP Hagler, TW Joswick, MD Parker, ID Smith, DL TI Measuring internal electric fields in organic light-emitting diodes using electroabsorption spectroscopy SO POLYMERS FOR ADVANCED TECHNOLOGIES LA English DT Article DE electroabsorption; organic light-emitting diode; device physics ID ELECTROLUMINESCENT DEVICES; CONFINEMENT; TRANSPORT; POLYMERS AB A widely applicable electroabsorption technique to measure internal electric fields in organic light-emitting diodes is presented. The technique exploits the change in the a.c. electroabsorption response in the presence of a d.c. electric field. The electroabsorption signal is modulated at the fundamental frequency of the a.c. test signal, in addition to the usual modulation at the second harmonic frequency, when a d.c. bias is present. In metal/organic film/metal devices employing different metal contacts there is a built-in electric field in the organic film caused by the difference in work function between the two contacts. The electroabsorption response at the fundamental frequency of the applied a.c, bias is measured as a function of an external d.c. bias. The electroabsorption signal is nulled when the applied d.c. bias cancels the built-in electric field established by the different metals. We apply this technique to measure changes in metal-polymer Schottky barrier heights as a function of the contact metal. In metal/multiple organic films/metal structures the electroabsorption signals from the constituent organic films are identified spectroscopically and measured at both the fundamental and second harmonic frequency of the a.c. test signal. The amplitudes of the electroabsorption responses are then used to determine the a.c. and d.c. electric fields present in the organic layers. We apply this technique to determine the d.c. electric field distribution within a multi-layer organic light-emitting diode. These results highlight the general applicability of electroabsorption methods to probe internal electric fields in organic light-emitting diodes (C) 1997 by John Wiley & Sons, Ltd. C1 UNIAX CORP,SANTA BARBARA,CA 93117. UNIV TEXAS,RICHARDSON,TX 75083. RP Campbell, IH (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 22 TC 22 Z9 22 U1 1 U2 12 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 1042-7147 J9 POLYM ADVAN TECHNOL JI Polym. Adv. Technol. PD JUL PY 1997 VL 8 IS 7 BP 417 EP 423 DI 10.1002/(SICI)1099-1581(199707)8:7<417::AID-PAT665>3.0.CO;2-5 PG 7 WC Polymer Science SC Polymer Science GA XQ225 UT WOS:A1997XQ22500007 ER PT J AU Olshansky, SJ Carnes, B Rogers, RG Smith, L AF Olshansky, SJ Carnes, B Rogers, RG Smith, L TI Infectious diseases - New and ancient threats to world health SO POPULATION BULLETIN LA English DT Article ID EDUCATIONAL DIFFERENTIALS; UNITED-STATES; MORTALITY; TRANSITION; EVOLUTION; VIRUSES AB Infectious and parasitic diseases (IPDs) are leading cause of death and disability in low-income countries, and are re-emerging as a serious health problem in developed countries. The recent rise in IPDs runs counter to the long-term decline made possible by advances in medicine-especially antibiotics and immunization-wide-scale improvements in sanitation and other living conditions, and growing public awareness of health and nutritional practices. After the eradication of smallpox in 1977, many health experts were optimistic that humans would soon conquer IPDs, which have caused untold suffering and death throughout history. But the HIV/AIDS epidemic opened the eyes of both health workers and the general public to the fact that IPDs had been on the resurgence for the past quarter-century. Since 1973, scientists have identified more than 28 new disease-causing microbes. Outbreaks of Ebola, dengue hemorrhagic fever, cholera, bubonic plague, and other serious diseases have been reported in many low-income countries, and multidrug-resistant organisms have surfaced throughout the world. This Population Bulletin examines the phenomenon of ''new'' and re-emerging IPDs from an international perspective. The authors discuss the factors that have influenced the re-emergence of these diseases, including urbanization, migration and travel, and agricultural practices that have increased exposure to diseases once confined to other animals and small geographic areas. They also review the changes in medical practice and treatment that have helped breed bacterial strains resistant to standard drug treatment. These diseases have led to some of this century's most rapid and dramatic demographic changes. HIV/AIDS, for example, has slowed sub-Saharan Africa's population growth and may halve the average life expectancy in some African countries. The authors explore strategies for slowing the rise of IPDs. These include efforts to stem poverty, improve immunization programs, and conduct educational campaigns. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. UNIV COLORADO,DEPT SOCIOL,BOULDER,CO. UNIV CHICAGO,DEPT MED,CHICAGO,IL 60637. UNIV CHICAGO,CTR AGING,CHICAGO,IL 60637. UNIV COLORADO,POPULAT PROGRAM,BOULDER,CO 80309. AUSTRALIAN NATL UNIV,NATL CTR EPIDEMIOL & POPULAT HLTH,CANBERRA,ACT,AUSTRALIA. NR 75 TC 9 Z9 9 U1 1 U2 13 PU POPULATION REFERENCE BUREAU INC PI WASHINGTON PA 1875 CONNECTICUT AVE, NW, STE 520, CIRCULATION DEPT, WASHINGTON, DC 20009-5728 SN 0032-468X J9 POPUL BULL JI Popul. Bull. PD JUL PY 1997 VL 52 IS 2 BP 2 EP & PG 52 WC Demography SC Demography GA XQ367 UT WOS:A1997XQ36700001 ER PT J AU Green, MA Emery, K Bucher, K King, DL Igari, S AF Green, MA Emery, K Bucher, K King, DL Igari, S TI Solar cell efficiency tables (version 10) SO PROGRESS IN PHOTOVOLTAICS LA English DT Article AB Updated tables showing an extensive listing of the highest independently confirmed efficiencies for solar cells and modules are presented. Guidelines for inclusion of results into these tables are outlined and several new entries since January 1997 are briefly described. (C) 1997 John Wiley & Sons, Ltd. C1 NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401. FRAUNHOFER INST SOLAR ENERGY SYST,D-79100 FREIBURG,GERMANY. SANDIA NATL LABS,DIV 6224,ALBUQUERQUE,NM 87123. JAPAN QUAL ASSURANCE ORG,SOLAR TECHNO CTR,SOLAR CELL TEST RES DIV,HAMAMATSU,SHIZUOKA 43112,JAPAN. RP Green, MA (reprint author), UNIV NEW S WALES,PHOTOVOLTAICS SPECIAL RES CTR,SYDNEY,NSW 2052,AUSTRALIA. NR 9 TC 17 Z9 17 U1 2 U2 13 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 1062-7995 J9 PROG PHOTOVOLTAICS JI Prog. Photovoltaics PD JUL-AUG PY 1997 VL 5 IS 4 BP 265 EP 268 DI 10.1002/(SICI)1099-159X(199707/08)5:4<265::AID-PIP177>3.0.CO;2-4 PG 4 WC Energy & Fuels; Materials Science, Multidisciplinary; Physics, Applied SC Energy & Fuels; Materials Science; Physics GA XU729 UT WOS:A1997XU72900005 ER PT J AU Lee, JC Fthenakis, VM Morris, SC Goldstein, GA Moskowitz, PD AF Lee, JC Fthenakis, VM Morris, SC Goldstein, GA Moskowitz, PD TI Projected photovoltaic energy impacts on US CO2 emissions: An integrated energy environment economic analysis SO PROGRESS IN PHOTOVOLTAICS LA English DT Article AB The potential role of photovoltaic technologies in reducing carbon dioxide (CO2) emissions in the USA was evaluated using an energy-environment-economic systems model. With a range of assumptions about future scenarios up to 2030, the model results pr or!ide an objective quantitative assessment of the prospects for photovoltaics in a competitive market. With the projected improvements in cost and efficiency, photovoltaics will compete favorably as a general source of electricity supply to the grid by, about 2010 in southwestern USA, This analysis indicates that photovoltaics has the potential to reach a total installed capacity of 140 GW by the year 2030, and to displace a cumulative 450 million metric tons of carbon emissions from 1995 to 2030. At the projected 2030 capacity, photovoltaics could displace over 64 million metric tons of carbon emissions a year, Under constraints an carbon emissions, photovoltaics becomes more cost effective and would further reduce carbon emissions from the US energy system. (C) 1997 John Wiley & Sons, Ltd. C1 BROOKHAVEN NATL LAB,BIOMED & ENVIRONM ASSESSMENT GRP,UPTON,NY 11973. NR 9 TC 1 Z9 1 U1 0 U2 1 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 1062-7995 J9 PROG PHOTOVOLTAICS JI Prog. Photovoltaics PD JUL-AUG PY 1997 VL 5 IS 4 BP 277 EP 285 PG 9 WC Energy & Fuels; Materials Science, Multidisciplinary; Physics, Applied SC Energy & Fuels; Materials Science; Physics GA XU729 UT WOS:A1997XU72900007 ER PT J AU Geisler, D Claria, JJ Minniti, D AF Geisler, D Claria, JJ Minniti, D TI Washington photometry of globular-cluster giants: Ten intermediate-metallicity clusters SO PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC LA English DT Article ID EFFECTIVE TEMPERATURES; METAL ABUNDANCE; SYSTEM; STARS; SPECTROSCOPY; NGC-3201; GALAXY AB One hundred and ten stars associated with ten intermediate-metallicity Galactic globular clusters have been investigated with the Washington photometric system. The data yield a luminosity class, temperature, and metal abundance for each star. The luminosity classification is used to separate field stars from cluster giants. Mean metal abundances for an average of ten member giants per cluster are determined to similar to 0.1 dex (internal error). These mean abundances are in good general agreement with existing metallicity scales. C1 ASTRON OBSERV,RA-5000 CORDOBA,ARGENTINA. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP Geisler, D (reprint author), KITT PEAK NATL OBSERV,NATL OPT ASTRON OBSERV,950 N CHERRY AVE,TUCSON,AZ 85719, USA. NR 37 TC 13 Z9 13 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 SN 0004-6280 J9 PUBL ASTRON SOC PAC JI Publ. Astron. Soc. Pac. PD JUL PY 1997 VL 109 IS 737 BP 799 EP 806 DI 10.1086/133947 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA XK769 UT WOS:A1997XK76900007 ER PT J AU VoDinh, T Velthorst, NH Moore, DS Schrader, B AF VoDinh, T Velthorst, NH Moore, DS Schrader, B TI Nomenclature, symbols, units, and their usage in spectrochemical analysis .16. Laser-based molecular spectroscopy for chemical analysis - Luminescence SO PURE AND APPLIED CHEMISTRY LA English DT Article AB This report is the 16th in a series on Spectrochemical Methods of Analysis issued by IUPAC Commission V-4. It is concerned with the use of lasers in molecular spectroscopy dealing with luminescence. C1 FREE UNIV AMSTERDAM,DEPT ANALYT CHEM,NL-1081 HV AMSTERDAM,NETHERLANDS. LOS ALAMOS NATL LAB,DIV CHEM & LASER SCI,LOS ALAMOS,NM 87544. UNIV ESSEN GESAMTHSCH,INST PHYS & THEORET CHEM,D-45117 ESSEN,GERMANY. RP VoDinh, T (reprint author), OAK RIDGE NATL LAB,DIV HLTH SCI RES,OAK RIDGE,TN 37831, USA. RI Moore, David/C-8692-2013 NR 3 TC 4 Z9 4 U1 0 U2 2 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0NE SN 0033-4545 J9 PURE APPL CHEM JI Pure Appl. Chem. PD JUL PY 1997 VL 69 IS 7 BP 1435 EP 1449 DI 10.1351/pac199769071435 PG 15 WC Chemistry, Multidisciplinary SC Chemistry GA XP126 UT WOS:A1997XP12600002 ER PT J AU Schrader, B Moore, DS AF Schrader, B Moore, DS TI Nomenclature, symbols, units, and their usage in spectrochemical analysis .18. Laser-based molecular spectroscopy for chemical analysis - Raman scattering processes SO PURE AND APPLIED CHEMISTRY LA English DT Article AB This report is 18th in a series on Spectrochemical Methods of Analysis issued by IUPAC Commission V.4. It is concerned with Raman scattering processes, usually induced by lasers, covering the UV, visible, and near infrared spectral regions, Raman scattering can be divided into linear and non linear processes. Due to their importance for chemical analysis, mainly the linear Raman effects are treated. C1 LOS ALAMOS NATL LAB,CHEM SCI & TECHNOL DIV,LOS ALAMOS,NM 87544. RP Schrader, B (reprint author), UNIV ESSEN GESAMTHSCH,INST PHYS & THEORET CHEM,D-45117 ESSEN,GERMANY. RI Moore, David/C-8692-2013 NR 10 TC 25 Z9 25 U1 0 U2 4 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0NE SN 0033-4545 J9 PURE APPL CHEM JI Pure Appl. Chem. PD JUL PY 1997 VL 69 IS 7 BP 1451 EP 1468 DI 10.1351/pac199769071451 PG 18 WC Chemistry, Multidisciplinary SC Chemistry GA XP126 UT WOS:A1997XP12600003 ER PT J AU Sultan, M Sturchio, N Hassan, FA Hamdan, MAR Mahmood, AM ElAlfy, Z Stein, T AF Sultan, M Sturchio, N Hassan, FA Hamdan, MAR Mahmood, AM ElAlfy, Z Stein, T TI Precipitation source inferred from stable isotopic composition of Pleistocene groundwater and carbonate deposits in the Western Desert of Egypt SO QUATERNARY RESEARCH LA English DT Article ID EASTERN SAHARA; WATER; PALEOCLIMATES; MONSOONS; HOLOCENE; CLIMATE; ZONE AB An Atlantic source of precipitation can be inferred from stable isotopic data (H and O) for fossil groundwaters and uraniumseries-dated carbonate spring deposits from eases in the Western Desert of Egypt, In the context of available stable isotopic data for fossil groundwaters throughout North Africa, the observed isotopic depletions (delta D -72 to -81 parts per thousand; delta(18)O -10.6 to -11.5 parts per thousand) of fossil (greater than or equal to 32,000 yr B.P.) groundwaters from the Nubian aquifer are best explained by progressive condensation of water vapor from paleowesterly wet oceanic air masses that traveled across North Africa and operated at least as far back as 450,000 yr before the present, The values of delta(18)O (17.1 to 25.9 parts per thousand) for 45,000- to >450,000-yr-old tufas and vein-filling calcite deposits from the Kharga and Farafra Gases are consistent with deposition from groundwaters having oxygen isotopic compositions similar to those of fossil groundwaters sampled recently at these locations. (C) 1997 University of Washington. C1 UCL, INST ARCHAEOL, LONDON WC1H 0PY, ENGLAND. CAIRO UNIV, FAC SCI, DEPT GEOL, CAIRO, EGYPT. AIN SHAMS UNIV, CAIRO, EGYPT. EGYPTIAN GEOL SURVEY & MIN AUTHOR, CAIRO, EGYPT. WASHINGTON UNIV, DEPT EARTH & PLANETARY SCI, ST LOUIS, MO 63130 USA. RP Sultan, M (reprint author), ARGONNE NATL LAB, DIV ENVIRONM RES, 9700 S CASS AVE, ARGONNE, IL 60439 USA. OI Hassan, Fekri/0000-0002-1687-0049 NR 41 TC 58 Z9 60 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 0033-5894 J9 QUATERNARY RES JI Quat. Res. PD JUL PY 1997 VL 48 IS 1 BP 29 EP 37 DI 10.1006/qres.1997.1907 PG 9 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA XQ623 UT WOS:A1997XQ62300003 ER PT J AU Albergo, S Caccia, Z Chen, CX Costa, S Crawford, HJ Cronqvist, M Engelage, J Flores, I Fonte, R Greiner, L Guzik, TG Insolia, A Knott, CN Ko, S Kuo, C Lindstrom, PJ Mazotta, J McMahon, M Mitchell, JW Potenza, R Romanski, J Russo, GV Soutoul, A Testard, O Tull, CE Tuve, C Waddington, CJ Webber, WR Wefel, JP AF Albergo, S Caccia, Z Chen, CX Costa, S Crawford, HJ Cronqvist, M Engelage, J Flores, I Fonte, R Greiner, L Guzik, TG Insolia, A Knott, CN Ko, S Kuo, C Lindstrom, PJ Mazotta, J McMahon, M Mitchell, JW Potenza, R Romanski, J Russo, GV Soutoul, A Testard, O Tull, CE Tuve, C Waddington, CJ Webber, WR Wefel, JP TI A heavy ion spectrometer system for the measurement of projectile fragmentation of relativistic heavy ions SO RADIATION MEASUREMENTS LA English DT Article ID CROSS-SECTIONS; NUCLEI; C-12 AB The Heavy Ion Spectrometer System (HISS) at the LBL Bevalac provided a unique facility for measuring projectile fragmentation cross-sections important in deconvolving the Galactic Cosmic Ray (GCR) source composition. The general characteristics of the apparatus specific to this application are described and the main features of the event reconstruction and analysis used in the TRANSPORT experiment are discussed. (C) 1997 Elsevier Science Ltd. C1 UNIV CATANIA,CSFNSM,CATANIA,ITALY. LOUISIANA STATE UNIV,BATON ROUGE,LA 70803. UNIV CALIF BERKELEY,SPACE SCI LAB,BERKELEY,CA 94720. LAWRENCE BERKELEY LAB,BERKELEY,CA. UNIV MINNESOTA,MINNEAPOLIS,MN. NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. CEN,SERV ASTROPHYS,SACLAY,FRANCE. UNIV NEW MEXICO,LAS CRUCES,NM. RP Albergo, S (reprint author), UNIV CATANIA,IST NAZL FIS NUCL,SEZ CATANIA,CATANIA,ITALY. RI Insolia, Antonio/M-3447-2015; TUVE', Cristina/P-3933-2015; Kuo, Chaincy/H-9475-2016 OI Insolia, Antonio/0000-0002-9040-1566; TUVE', Cristina/0000-0003-0739-3153; Kuo, Chaincy/0000-0001-7958-8764 NR 18 TC 8 Z9 8 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1350-4487 J9 RADIAT MEAS JI Radiat. Meas. PD JUL PY 1997 VL 27 IS 4 BP 549 EP 567 DI 10.1016/S1350-4487(97)00020-6 PG 19 WC Nuclear Science & Technology SC Nuclear Science & Technology GA YF771 UT WOS:A1997YF77100002 ER PT J AU Bergstrom, PM Pratt, RH AF Bergstrom, PM Pratt, RH TI An overview of the theories used in Compton scattering calculations SO RADIATION PHYSICS AND CHEMISTRY LA English DT Article ID K-SHELL ELECTRONS; X-RAY-SCATTERING; TO-SINGLE PHOTOIONIZATION; GAMMA-RAYS; DOUBLE-IONIZATION; BOUND ELECTRONS; INFRARED DIVERGENCE; CROSS-SECTION; SYNCHROTRON-RADIATION; EXCITATION-IONIZATION AB This paper discusses theoretical approaches for investigating Compton scattering from bound atomic electrons. It particularly emphasizes the understanding of methods currently used to obtain the scattered photon energy distribution at fixed scattering angle. This distribution is dominated by three features: the Compton line or peak, the resonant-Raman-Compton scattering and the infrared divergence at soft scattered photon energies. No single common approximation accesses all three regions, though they are all exhibited analytically in the nonrelativistic hydrogenic case. S-matrix calculations describe all of these features. The usual approximations utilized for Compton scattering are discussed and assessed in comparison with the more exact, relativistic S-matrix calculations. Finally, some recent developments in the theory of Compton scattering from bound electrons are noted. These include the effort to describe the double ionization of helium by Compton scattering and the theoretical analysis of the more completely differential Compton scattering experiment in which the ejected electron is also observed. Published by Elsevier Science Ltd. C1 UNIV PITTSBURGH,DEPT PHYS & ASTRON,PITTSBURGH,PA 15260. RP Bergstrom, PM (reprint author), LAWRENCE LIVERMORE NATL LAB,N DIV,LIVERMORE,CA 94551, USA. NR 116 TC 51 Z9 51 U1 2 U2 10 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 JUL PY 1997 VL 50 IS 1 BP 3 EP 29 DI 10.1016/S0969-806X(97)00022-4 PG 27 WC Chemistry, Physical; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical SC Chemistry; Nuclear Science & Technology; Physics GA XG714 UT WOS:A1997XG71400002 ER PT J AU Frome, EL Cragle, DL Watkins, JP Wing, S Shy, CM Tankersley, WG West, CM AF Frome, EL Cragle, DL Watkins, JP Wing, S Shy, CM Tankersley, WG West, CM TI A mortality study of employees of the nuclear industry in Oak Ridge, Tennessee SO RADIATION RESEARCH LA English DT Article ID ATOMIC-ENERGY-AUTHORITY; REGRESSION-MODELS; CANCER MORTALITY; RADIATION; WORKERS; RATES; EXPOSURES AB An analysis was conducted of 27,982 deaths among 106,020 persons employed at four Federal nuclear plants in Oak Ridge, Tennessee, between 1943 and 1985. The main objectives were to extend the evaluation of the health effects of employment in the nuclear industry in Oak Ridge to include most workers who were omitted from earlier studies, to compare the mortality experience of workers among the facilities, to address methodological problems that occur when individuals employed at more than one facility are included in the analysis, and to conduct dose-response analyses for those individuals with potential exposure to external radiation. All-cause mortality and all-cancer mortality were in close agreement with national rates. The only notable excesses occurred for white males for lung cancer [standardized mortality ratio (SMR) = 1.18, 1,849 deaths] and non-malignant respiratory disease (SMR = 1.12, 1,568 deaths). A more detailed analysis revealed substantial differences in death rates among workers at the Oak Ridge plants. Evaluation of internally adjusted log SMRs using Poisson regression showed that workers employed only at Tennessee Eastman Corporation or K-25 and at multiple facilities had higher death rates than similar workers employed only at X-10 or Y-12, and that the differences were primarily due to non-cancer causes. Analysis of selected cancer causes for white males indicated large differences among the workers at the different facilities for lung cancer, leukemia and other lymphatic cancer. Dose-response analyses for external penetrating radiation were limited to a subcohort of 28,347 white males employed at X-10 or Y-12. Their collective recorded dose equivalent was 376 Sv. There was a strong ''healthy worker effect'' in this subcohort - all-cause SMR = 0.80 (4,786 deaths) and all-cancer SR IR = 0.87 (1,134 deaths). Variables included in the analyses were age, birth cohort, a measure of socioeconomic status, length of employment, internal radiation exposure potential and facility. For external radiation dose with a 10-year lag, the excess relative risk was 0.31 per Sv (95% CI = -0.16, 1.01) for all causes and 1.45 per Sv (95% CI = 0.15, 3.48) for all cancer. The estimated excess relative risk for leukemia was negative but imprecisely determined. A preliminary dose adjustment procedure was developed to compensate for missing dose but not other dosimetry errors. Results of the analyses using the adjusted doses suggest that the effect of missing dose is an upward bias in dose-response coefficients and test statistics. (C) 1997 by Radiation Research Society. C1 OAK RIDGE INST SCI & EDUC,CTR EPIDEMIOL RES,OAK RIDGE,TN 37831. UNIV N CAROLINA,DEPT EPIDEMIOL,CHAPEL HILL,NC 27599. RP Frome, EL (reprint author), OAK RIDGE NATL LAB,MATH SCI SECT,POB 2008,OAK RIDGE,TN 37831, USA. NR 42 TC 46 Z9 46 U1 0 U2 3 PU RADIATION RESEARCH SOC PI OAK BROOK PA 2021 SPRING RD, STE 600, OAK BROOK, IL 60521 SN 0033-7587 J9 RADIAT RES JI Radiat. Res. PD JUL PY 1997 VL 148 IS 1 BP 64 EP 80 DI 10.2307/3579540 PG 17 WC Biology; Biophysics; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Biophysics; Radiology, Nuclear Medicine & Medical Imaging GA XJ309 UT WOS:A1997XJ30900009 PM 9216620 ER PT J AU Zhang, YR Woloschak, GE AF Zhang, YR Woloschak, GE TI Rb and p53 gene deletions in lung adenocarcinomas from irradiated and control mice SO RADIATION RESEARCH LA English DT Article ID RETINOBLASTOMA GENE; DOSE-RATE; ONCOGENIC TRANSFORMATION; MAMMALIAN-CELLS; TUMOR; EXPRESSION; RADIATION; MUTATION; CANCER; CARCINOGENESIS AB This study was conducted on mouse lung adenocarcinoma tissues that were treated with formalin and embedded in paraffin 25 years ago to investigate the large gene deletions of Rb and p53 in B6CF(1) male mice. A total of 80 lung tissue samples from irradiated mice and 40 lung samples from nonirradiated controls were selected randomly and examined in the Rb portion of this study. The results showed a significantly (P < 0.05) higher percentage of Rb deletions in lung adenocarcinomas from mice exposed to 60 once-weekly gamma-ray doses than those from mice receiving 24 once-weekly gamma-ray doses at low doses and low dose rates; however, the percentage was not significantly different (P > 0.05) from that for spontaneous lung adenocarcinomas or lung adenocarcinomas from mice exposed to single-dose gamma irradiation at a similar total dose. Rb fragments 3 (71%) and 5 (67%), the parts of the gene that encoded the pocket binding region of Rb protein to adenovirus E1A and SV40 T-antigen, were the most frequently deleted fragments. Analysis of p53 gene deletion was carried out on normal lungs and lung adenocarcinomas that were initially found to bear Rb deletions. Exons 1, 4, 5, 6 and 9 were chosen to be analyzed. The data showed that 30 (97%) of 31 normal lungs and lung adenocarcinomas had p53 deletions. Exons 4 (83%) and 5 (90%) were the most frequently deleted among tested exons. Mice exposed to neutrons 60 times on a once-weekly schedule had a higher percentage of complete p53 deletions (5/8; 63%) than those exposed to gamma rays 60 times on a once-weekly schedule (2/8; 25%). We conclude that p53 deletions may be one of the major mutational events in the tumorigenesis of lung adenocarcinomas in the irradiated B6CF(1) mice. (C) 1997 by Radiation Research Society. C1 ARGONNE NATL LAB,CTR MECHANIST BIOL & BIOTECHNOL,ARGONNE,IL 60439. RI Woloschak, Gayle/A-3799-2017 OI Woloschak, Gayle/0000-0001-9209-8954 FU NIEHS NIH HHS [ES 07141-02] NR 44 TC 11 Z9 12 U1 0 U2 1 PU RADIATION RESEARCH SOC PI OAK BROOK PA 2021 SPRING RD, STE 600, OAK BROOK, IL 60521 SN 0033-7587 J9 RADIAT RES JI Radiat. Res. PD JUL PY 1997 VL 148 IS 1 BP 81 EP 89 DI 10.2307/3579541 PG 9 WC Biology; Biophysics; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Biophysics; Radiology, Nuclear Medicine & Medical Imaging GA XJ309 UT WOS:A1997XJ30900010 PM 9216621 ER PT J AU Bao, SP Harwood, PW Wood, BH Chrisler, WB Groch, KM Brooks, AL AF Bao, SP Harwood, PW Wood, BH Chrisler, WB Groch, KM Brooks, AL TI Comparative clastogenic sensitivity of respiratory tract cells to gamma rays SO RADIATION RESEARCH LA English DT Article ID TRACHEAL EPITHELIAL-CELLS; DEEP-LUNG FIBROBLASTS; IN-VIVO; II CELLS; PULMONARY CARCINOGENESIS; CHROMOSOME-ABERRATIONS; MAMMALIAN-CELLS; RISK ASSESSMENT; WISTAR RAT; DNA-DAMAGE AB To understand the relationships between exposure and damage to different cell populations in the respiratory tract, methods were developed to culture deep-lung fibroblasts and epithelial cells from the nose, trachea and deep lungs. Female F-344 Fischer and male Wistar rats were exposed to 1-5 Gy of Co-60 gamma rays at a dose rate of 0.4 Gy/min. Cells were isolated for short-term culture, and the incidences of binucleated cells and micronuclei were determined. The incidences of micronuclei were determined in cytochalasin-B-induced binucleated cells at 72 h for nasal and tracheal tissue and 96 h for deep-lung fibroblasts and epithelial cells. Maximum frequencies of binucleated cells were found in the control nonirradiated cells at these harvest times, and the frequencies were not significantly affected at these harvest times by radiation exposure. No significant differences were found in the frequencies of micronuclei induced in the nasal epithelial cells isolated from female F-344 Fischer or male Wistar rats. Fibroblasts cultured in different media and isolated from either female F-344 Fischer or male Wistar rats also showed a similar frequency of micronuclei. Over the doses tested, the frequency of micronuclei in the respiratory tract cells increased linearly with the dose. The slopes were 92.2 +/- 9.2, 76.2 +/- 7.9, 32.8 +/- 2.4 and 28.7 +/- 3.4 micronuclei/1000 binucleated cells/Gy for deep-lung epithelial cells, deep-lung fibroblasts, tracheal epithelial cells and nasal epithelial cells, respectively. Deep-lung epithelial or fibroblast cells were about two to three times as sensitive for clastogenic damage as nasal and tracheal epithelial cells. The measurement of micronuclei in isolated respiratory tract cells is very useful in assessing cytogenetic damage induced in different cell types by radiation. (C) 1997 by Radiation Research Society. C1 PACIFIC NW LAB, RICHLAND, WA 99352 USA. RP Bao, SP (reprint author), WASHINGTON STATE UNIV, US TRANSURANIUM & URANIUM REGISTRIES, 100 SPROUT RD, RICHLAND, WA 99352 USA. RI WSU, USTUR/I-1056-2013 NR 47 TC 10 Z9 10 U1 0 U2 2 PU RADIATION RESEARCH SOC PI OAK BROOK PA 2021 SPRING RD, STE 600, OAK BROOK, IL 60521 SN 0033-7587 J9 RADIAT RES JI Radiat. Res. PD JUL PY 1997 VL 148 IS 1 BP 90 EP 97 DI 10.2307/3579542 PG 8 WC Biology; Biophysics; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Biophysics; Radiology, Nuclear Medicine & Medical Imaging GA XJ309 UT WOS:A1997XJ30900011 PM 9216622 ER PT J AU Allison, SW Gillies, GT AF Allison, SW Gillies, GT TI Remote thermometry with thermographic phosphors: Instrumentation and applications SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Review ID LASER-INDUCED FLUORESCENCE; ACTIVATED GARNET PHOSPHORS; OPTIC TEMPERATURE SENSOR; DIGITAL PARALLEL ACQUISITION; THERMAL IMAGING-SYSTEM; DECAY-TIME; THIN-FILMS; FIBEROPTIC THERMOMETRY; LIFETIME MEASUREMENTS; PRECISION LIMITS AB The temperature-dependent characteristics of fluorescence of several rare-earth-doped ceramic phosphors has made these materials the focus of a major effort in the field of noncontact thermometry over the past few decades. These ''thermographic phosphors,'' e.g., Y2O3:Eu, have been used for remote measurements of the temperatures of both static and moving surfaces, and have performed many other tasks that standard sensors (thermocouples, thermistors, etc.) cannot. The range of usefulness of this class of materials extends from cryogenic temperatures to those approaching 2000 degrees C. The instrumentation needed for this type of thermometry has followed many different lines of development, and this evolution has produced a wide variety of both field- and laboratory-grade systems that are now described in the literature. In general, the technique offers high sensitivity (approximate to 0.05 degrees C), robustness (e.g., stability of the sensor sample in harsh environments), and NIST traceability. In addition, such systems have been successfully adapted to make remotely sensed measurements of pressure, heat flux, shear stress, and strain. In this review, we summarize the physical mechanisms that form the basis for the technique, and then catalog and discuss the instrumentation-related aspects of several different remote thermometry systems that employ thermographic phosphors as the sensors. (C) 1997 American Institute of Physics. C1 UNIV VIRGINIA, HLTH SCI CTR, DEPT BIOMED ENGN, CHARLOTTESVILLE, VA 22908 USA. VIRGINIA COMMONWEALTH UNIV, MED COLL VIRGINIA, DIV NEUROSURG, RICHMOND, VA 23298 USA. OAK RIDGE NATL LAB, ENGN TECHNOL DIV, OAK RIDGE, TN 37831 USA. UNIV VIRGINIA, DEPT MECH AEROSP & NUCL ENGN, CHARLOTTESVILLE, VA 22901 USA. OI Allison, Stephen/0000-0002-5887-5403 NR 280 TC 342 Z9 346 U1 16 U2 123 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD JUL PY 1997 VL 68 IS 7 BP 2615 EP 2650 DI 10.1063/1.1148174 PG 36 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA XL851 UT WOS:A1997XL85100001 ER PT J AU Reister, DB AF Reister, DB TI The least squares fit of a hyperplane to uncertain data SO ROBOTICA LA English DT Article DE hyperplane; least squares fit; sensors; robotic systems AB Sensor based robotic systems are an important emerging technology. When robots are working in unknown or partially known environments, they need range sensors that will measure the Cartesian coordinates of surfaces of objects in their environment. Like any sensor, range sensors must be calibrated. The range sensors can be calibrated by comparing a measured surface shape to a known surface shape. The most simple surface is a plane and many physical objects have planar surfaces. Thus, an important problem in the calibration of range sensors is to find the best (least squares) fit of a plane to a set of 3D points. We have formulated a constrained optimization problem to determine the least squares fit of a hyperplane to uncertain data. The first order necessary conditions require the solution of an eigenvalue problem. We have shown that the solution satisfies the second order conditions (the Hessian matrix is positive definite). Thus, our solution satisfies the sufficient conditions for a local minimum. We have performed numerical experiments that demonstrate that our solution is superior to alternative methods. RP Reister, DB (reprint author), OAK RIDGE NATL LAB,CTR ENGN SYST ADV RES,POB 2008,BLDG 6025,MS-6364,OAK RIDGE,TN 37831, USA. NR 4 TC 0 Z9 0 U1 0 U2 3 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 SN 0263-5747 J9 ROBOTICA JI Robotica PD JUL-AUG PY 1997 VL 15 BP 461 EP 464 DI 10.1017/S0263574797000556 PN 4 PG 4 WC Robotics SC Robotics GA XK794 UT WOS:A1997XK79400014 ER PT J AU Bhansali, S Sood, DK Evans, PJ Brown, IG AF Bhansali, S Sood, DK Evans, PJ Brown, IG TI Ion implantation for nucleation of electroless Ni films on <100> Si SO SENSORS AND ACTUATORS A-PHYSICAL LA English DT Article; Proceedings Paper CT EUROSENSORS X Meeting CY SEP 08-11, 1996 CL LOUVAIN, BELGIUM DE electroless nickel films; ion implantation; silicon ID POLYIMIDE; GROWTH AB Our previous work has recently established ion implantation as a viable technique to seed electroless Cu films on several substrates. In this work we employ this technique for selective nucleation of electroless Ni films on Si substrates. Pd ions are implanted into [100] Si using a metal vapour vacuum are (MEVVA) ion implanter. The implantation dose is varied between 7E14 and 3.6E16 ions cm(-2). The substrates and plated films are studied with Rutherford backscattering spectroscopy and channelling (RBS-C), SEM, EDX, profilometery and the scorch tape test (STT). A threshold dose required for nucleation of electroless Ni plating has been determined. Plated films, several microns thick, with good adhesion have been made using this technique. The effect of implantation parameters such as ion energy, ion dose and of plating conditions on the growth kinetics and morphology of the plated films has been investigated. A test structure in the shape of a coil has been fabricated using this technique. (C) 1997 Elsevier Science S.A. C1 ROYAL MELBOURNE INST TECHNOL,DEPT ELECT ENGN,MELBOURNE,VIC 3000,AUSTRALIA. ANSTO,LUCAS HTS LABS,LUCAS HEIGHTS,NSW 2234,AUSTRALIA. LAWRENCE BERKELEY LAB,BERKELEY,CA 92720. RI Bhansali, Shekhar/E-4705-2010 NR 8 TC 5 Z9 6 U1 0 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0924-4247 J9 SENSOR ACTUAT A-PHYS JI Sens. Actuator A-Phys. PD JUL PY 1997 VL 62 IS 1-3 BP 705 EP 710 DI 10.1016/S0924-4247(97)01622-1 PG 6 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA YD906 UT WOS:A1997YD90600042 ER PT J AU Katsevich, AI AF Katsevich, AI TI Range of the radon transform on functions which do not decay fast at infinity SO SIAM JOURNAL ON MATHEMATICAL ANALYSIS LA English DT Article DE range; Radon transform; moment conditions; asymptotic expansion ID SPACE AB Let an integer m greater than or equal to 0 be fixed. Let chi(m) be the space of functions f is an element of C-infinity(R-n) that admit an asymptotic expansion f(r beta) similar to Sigma(k=m)(infinity) psi(k)(beta)/r(n+k), r --> infinity, psi(k) is an element of C-infinity(Sn-1), and the expansion can be differentiated with respect to x = r beta any number of times. In this paper, pre derive a precise characterization of the range of the Radon transform R acting on chi(m); that is, we explicitly describe the space Z(m) = R chi(m). The conditions which describe the space Z(m) are easily verifiable. C1 LOS ALAMOS NATL LAB,CIC3 DIV,LOS ALAMOS,NM 87545. NR 15 TC 6 Z9 6 U1 0 U2 0 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 SN 0036-1410 J9 SIAM J MATH ANAL JI SIAM J. Math. Anal. PD JUL PY 1997 VL 28 IS 4 BP 852 EP 866 DI 10.1137/S0036141095289518 PG 15 WC Mathematics, Applied SC Mathematics GA XG760 UT WOS:A1997XG76000004 ER PT J AU Day, D AF Day, D TI An efficient implementation of the nonsymmetric Lanczos algorithm SO SIAM JOURNAL ON MATRIX ANALYSIS AND APPLICATIONS LA English DT Article DE Lanczos algorithm; breakdown; sparse eigenvalue problems; biorthogonalization methods ID PERTURBATION BOUNDS; UNSYMMETRIC MATRICES; QR FACTORIZATIONS; ARNOLDI METHOD; REORTHOGONALIZATION; ORTHOGONALIZATION; DECOMPOSITIONS; CHOLESKY; LU AB Lanczos vectors computed in finite precision arithmetic by the three-term recurrence tend to lose their mutual biorthogonality One either accepts this loss and takes more steps or re-biorthogonalizes the Lanczos vectors at each step. Far the symmetric case, there is a compromise approach. This compromise, known as maintaining semiorthogonality, minimizes the cost of reorthogonalization. This paper extends the compromise to the true-sided Lanczos algorithm and justifies the new algorithm. The compromise is called maintaining semiduality. An advantage of maintaining semiduality is that the computed tridiagonal is a perturbation of a matrix that is exactly similar to the appropriate projection of the given matrix onto the computed subspaces. Another benefit is that the simple two-sided Gram-Schmidt procedure is a viable way to correct for loss of duality. A numerical experiment is included in which our Lanczos code is significantly more efficient than Arnoldi's method. RP Day, D (reprint author), SANDIA NATL LABS, POB 5800, ALBUQUERQUE, NM 87185 USA. NR 38 TC 14 Z9 15 U1 0 U2 0 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 SN 0895-4798 J9 SIAM J MATRIX ANAL A JI SIAM J. Matrix Anal. Appl. PD JUL PY 1997 VL 18 IS 3 BP 566 EP 589 DI 10.1137/S0895479895292503 PG 24 WC Mathematics, Applied SC Mathematics GA XG759 UT WOS:A1997XG75900004 ER PT J AU Howell, LH Bell, JB AF Howell, LH Bell, JB TI An adaptive mesh projection method for viscous incompressible flow SO SIAM JOURNAL ON SCIENTIFIC COMPUTING LA English DT Article DE projection method; incompressible flow; adaptive mesh refinement ID NAVIER-STOKES EQUATIONS; REFINEMENT AB Many fluid flow problems of practical interest-particularly at high Reynolds number-are characterized by small regions of complex and rapidly varying fluid motion surrounded by larger regions of relatively smooth Bow. Efficient solution of such problems requires an adaptive mesh refinement capability to concentrate computational effort where it is most needed. We present in this paper a fractional step version of Chorin's projection method for incompressible flow, with adaptive mesh refinement, which is second-order accurate in both space and time. Convection terms are handled by a high-resolution upwind method which provides excellent resolution of small-scale features of the Bow, while a multilevel iterative scheme efficiently solves the parabolic and elliptic equations associated with viscosity and the projection. Numerical examples demonstrate the performance of the method on two-dimensional problems involving vortex spindown with viscosity and inviscid vortex merger. RP Howell, LH (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY NATL LAB,MAIL STOP 50D,BERKELEY,CA 94720, USA. NR 21 TC 30 Z9 33 U1 3 U2 8 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 SN 1064-8275 J9 SIAM J SCI COMPUT JI SIAM J. Sci. Comput. PD JUL PY 1997 VL 18 IS 4 BP 996 EP 1013 DI 10.1137/S1064827594270555 PG 18 WC Mathematics, Applied SC Mathematics GA XG742 UT WOS:A1997XG74200003 ER PT J AU Hovland, P Bischof, C Spiegelman, D Casella, M AF Hovland, P Bischof, C Spiegelman, D Casella, M TI Efficient derivative codes through automatic differentiation and interface contraction: An application in biostatistics SO SIAM JOURNAL ON SCIENTIFIC COMPUTING LA English DT Article DE automatic differentiation; computational differentiation; interface contraction; log-likelihood functions; derivatives; ADIFOR AB Developing code for computing the first- and higher-order derivatives of a function by hand can be very time consuming and is prone to errors. Automatic differentiation has proven capable of producing derivative codes with very little effort on the part of the user. Automatic differentiation avoids the truncation errors characteristic of divided difference approximations. However, the derivative code produced by automatic differentiation can be significantly less efficient than one produced by hand. This shortcoming may be overcome by utilizing insight into the high-level structure of a computation. This paper focuses on how to take advantage of the fact that the number of variables passed between subroutines frequently is small compared with the number of variables with respect to which one wishes to differentiate. Such an ''interface contraction,'' coupled with the associativity of the chain rule for differentiation, allows one to apply automatic differentiation in a more judicious fashion, resulting in much more efficient code for the computation of derivatives, A case study involving the ADIFOR (Automatic Differentiation of Fortran) tool and a program for maximizing a logistic-normal likelihood function developed from a problem in nutritional epidemiology is examined, and performance figures are presented. C1 ARGONNE NATL LAB, DIV MATH & COMP SCI, ARGONNE, IL 60439 USA. HARVARD UNIV, SCH PUBL HLTH, DEPT EPIDEMIOL, BOSTON, MA 02115 USA. HARVARD UNIV, SCH PUBL HLTH, DEPT BIOSTAT, BOSTON, MA 02115 USA. RP Hovland, P (reprint author), UNIV ILLINOIS, DEPT COMP SCI, 1304 W SPRINGFIELD AVE, URBANA, IL 61801 USA. RI Bischof, Christian/D-2897-2009 NR 29 TC 16 Z9 17 U1 0 U2 1 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 1064-8275 J9 SIAM J SCI COMPUT JI SIAM J. Sci. Comput. PD JUL PY 1997 VL 18 IS 4 BP 1056 EP 1066 DI 10.1137/S1064827595281800 PG 11 WC Mathematics, Applied SC Mathematics GA XG742 UT WOS:A1997XG74200007 ER PT J AU Mahmoudjafari, M Kluitenberg, GJ Havlin, JL Sisson, JB Schwab, AP AF Mahmoudjafari, M Kluitenberg, GJ Havlin, JL Sisson, JB Schwab, AP TI Spatial variability of nitrogen mineralization at the field scale SO SOIL SCIENCE SOCIETY OF AMERICA JOURNAL LA English DT Article ID SOIL PROPERTIES; PATTERNS AB Spatial variability of N mineralization represents a potential problem in predicting the quantity of N mineralized under field conditions, An understanding of mineralization variability is needed if prediction of potential mineralization is to be incorporated into fertilizer recommendation models, The objective of this study was to characterize spatial variability of N mineralization in a Kansas agricultural field, intact undisturbed soil cores were collected at 108 locations within a 1.7-ha field following wheat (Triticum aestivum L.) harvest, The undisturbed cores were incubated aerobically, and NO3- was leached periodically as a measure of mineralization. Variability was characterized by examining the spatially distributed values of mineralization potential, N-0, and mineralization rate constant, k, parameters of the classical first-order mineralization rate model, Values of N-0 were distributed normally with low variability (coefficient of variation [CV] = 15%) and weak autocorrelation, Values of k also followed a normal distribution with low variability (CV = 14%) but were spatially independent, Both N-0 and k determined the spatial pattern of N-m, the quantity of N mineralized at a particular time, Variability in k controlled the spatial pattern of N-m earlier in the incubation period, and variability in N-0 controlled the spatial pattern late in the incubation period, The incubation approach used in this study allowed characterization of the spatial patterns in N-0, but the spatial variability of k observed in this study may not adequately represent field conditions because conditions of constant temperature and water content were used. C1 KANSAS STATE UNIV,DEPT AGRON,MANHATTAN,KS 66506. EG&G IDAHO INC,IDAHO NATL ENGN LAB,IDAHO FALLS,ID 83415. OI Schwab, Arthur/0000-0002-0702-6823 NR 22 TC 22 Z9 25 U1 1 U2 6 PU SOIL SCI SOC AMER PI MADISON PA 677 SOUTH SEGOE ROAD, MADISON, WI 53711 SN 0361-5995 J9 SOIL SCI SOC AM J JI Soil Sci. Soc. Am. J. PD JUL-AUG PY 1997 VL 61 IS 4 BP 1214 EP 1221 PG 8 WC Soil Science SC Agriculture GA XN241 UT WOS:A1997XN24100029 ER PT J AU Menchero, JG Fadley, CS Panaccione, G Sirotti, F Rossi, G AF Menchero, JG Fadley, CS Panaccione, G Sirotti, F Rossi, G TI Linear magnetic dichroism in the angular distribution of Ni 3p photoelectrons SO SOLID STATE COMMUNICATIONS LA English DT Article ID CORE-LEVEL PHOTOEMISSION; RAY CIRCULAR-DICHROISM; FERROMAGNETIC NICKEL; RESOLVED PHOTOEMISSION; FE; IRON; SPECTRA; LIGHT AB The magnetic dichroism of the Ni3p photoemission signal has been measured by means of chiral experiments with linearly polarized synchrotron radiation and calculated by means of a many-body small-cluster model. The high energy/angular resolution of the experiment and an improved statistics with respect to previous measurements with circularly polarized light, show that the experimentally measured effect is comparable to, but smaller than, the calculated effect. Thus previous conclusions on a large enhancement of the surface magnetic orbital moment in Ni are not confirmed. (C) 1997 Published by Elsevier Science Ltd. All rights reserved. C1 UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. UNIV CALIF DAVIS,DEPT PHYS,DAVIS,CA 95616. MESR,CEA,CNRS,LAB UTILISAT RAYONNEMENT ELECTROMAGNET,F-91405 ORSAY,FRANCE. UNIV NEUCHATEL,INST PHYS,CH-2000 NEUCHATEL,SWITZERLAND. ETH ZURICH,FESTKORPERPHYS LAB,CH-8093 ZURICH,SWITZERLAND. UNIV MODENA,INFM,DIPARTIMENTO FIS,I-41100 MODENA,ITALY. RP Menchero, JG (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720, USA. RI Sirotti, Fausto/F-3052-2017 OI Sirotti, Fausto/0000-0001-8753-8425 NR 32 TC 6 Z9 6 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0038-1098 J9 SOLID STATE COMMUN JI Solid State Commun. PD JUL PY 1997 VL 103 IS 3 BP 197 EP 201 DI 10.1016/S0038-1098(97)00163-4 PG 5 WC Physics, Condensed Matter SC Physics GA XF840 UT WOS:A1997XF84000014 ER PT J AU Pillep, B Froba, M Phillips, MLF Wong, J Stucky, GD Behrens, P AF Pillep, B Froba, M Phillips, MLF Wong, J Stucky, GD Behrens, P TI Xanes spectroscopic study of the electronic structure of Ti in KTiOPO4 and some of its isomorphous compounds SO SOLID STATE COMMUNICATIONS LA English DT Article DE XANES; optical properties; synchrotron radiation; X-ray spectroscopies ID K-EDGE ABSORPTION; DEPENDENCE; QUICK AB Ti K-edge XANES spectra of KTiOPO4, an important material for second harmonic generation (SHG) and several of its isomorphs including MTiOPO4 (M = Na, Ag) and KTi1-xSnxOPO4 (x = 0.1, 0.4, 0.5, 0.6) have been recorded. The pre-edge regions of these spectra exhibit characteristic features that are assigned to electronic transitions from the Ti Is to the unoccupied Ti 3d and 4p levels. The intensities of these pre-edge features are very sensitive to slight changes in the asymmetry of the octahedral Ti coordination sphere. Thus, in the series KTi1-xSnxOPO4 the successive substitution of Ti by Sn causes a substantial decrease of the Ti coordination asymmetry. This decrease is correlated with a loss in SHG intensity. (C) 1997 Elsevier Science Ltd. C1 UNIV MUNICH,INST ANORGAN CHEM,D-80333 MUNICH,GERMANY. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551. UNIV CALIF SANTA BARBARA,DEPT CHEM,SANTA BARBARA,CA 93106. RI Froba, Michael/B-2888-2010 NR 16 TC 6 Z9 6 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0038-1098 J9 SOLID STATE COMMUN JI Solid State Commun. PD JUL PY 1997 VL 103 IS 3 BP 203 EP 207 DI 10.1016/S0038-1098(97)00173-7 PG 5 WC Physics, Condensed Matter SC Physics GA XF840 UT WOS:A1997XF84000015 ER PT J AU Price, EA Bourne, SL Radbourne, R Lawton, PA Lamerdin, J Thompson, LH Arrand, JE AF Price, EA Bourne, SL Radbourne, R Lawton, PA Lamerdin, J Thompson, LH Arrand, JE TI Rare microsatellite polymorphisms in the DNA repair genes XRCC1, XRCC3 and XRCC5 associated with cancer in patients of varying radiosensitivity SO SOMATIC CELL AND MOLECULAR GENETICS LA English DT Article ID STRAND-BREAK-REPAIR; NONPOLYPOSIS COLORECTAL-CANCER; SISTER-CHROMATID EXCHANGE; V(D)J RECOMBINATION; MAMMALIAN-CELLS; PROTEIN-KINASE; FIBROBLASTS; INSTABILITY; MUTATIONS; MUTAGENS AB DNA repair defects might contribute both to cancer progression and to the extreme reactions to radiotherapy observed in similar to 5% of patients. Polymorphic microsatellites in three DNA repair genes, XRCC1, XRCC3 and XRCC5, were analyzed for possible linkage to cancer status or clinical radiosensitivity, XRCC1, 3 and 5 proteins are involved in single-strand DNA break rejoining, recombinational repair and double-strand DNA break rejoining respectively. Mendelianly inherited microsatellite polymorphisms in these genes were analyzed in three groups: volunteers with no cancer history; radiosensitive cancer patients; cancer patients with acceptable reactions to radiotherapy. Rare heterozygous alterations in all three gene regions were found solely in the cancer subpopulation. Association testing between these rare polymorphisms and cancer status revealed a significant association for XRCC1 (P = 0.005), and XRCC3 (P = 0.004). There was also an association between these polymorphisms and clinical radiosensitivity for XRCC1 (P = 0.03), and XRCC3 (P = 0.005). C1 Brunel Univ, Dept Biol & Biochem, Human Mol Genet Grp, Uxbridge UB8 3PH, Middx, England. Mt Vernon Hosp, NHS Trust, Mt Vernon Ctr Canc Treatment, Northwood HA6 2JR, Middx, England. Watford Hosp, NHS Trust, Mt Vernon Ctr Canc Treatment, Northwood HA6 2JR, Middx, England. Univ Calif Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94551 USA. RP Price, EA (reprint author), Brunel Univ, Dept Biol & Biochem, Human Mol Genet Grp, Uxbridge UB8 3PH, Middx, England. NR 28 TC 71 Z9 73 U1 0 U2 2 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0740-7750 J9 SOMAT CELL MOLEC GEN JI Somat.Cell Mol.Genet. PD JUL PY 1997 VL 23 IS 4 BP 237 EP 247 DI 10.1007/BF02674415 PG 11 WC Biochemistry & Molecular Biology; Cell Biology; Genetics & Heredity SC Biochemistry & Molecular Biology; Cell Biology; Genetics & Heredity GA ZE440 UT WOS:000072792800001 PM 9542526 ER PT J AU Crandall, DH AF Crandall, DH TI The value of a national ignition facility SO TECHNOLOGY REVIEW LA English DT Letter C1 US DOE,NIF,WASHINGTON,DC 20585. RP Crandall, DH (reprint author), US DOE,OFF INERTIAL FUS,WASHINGTON,DC 20585, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MASS INST TECHNOL PI CAMBRIDGE PA BUILDING W59, CAMBRIDGE, MA 02139 SN 0040-1692 J9 TECHNOL REV JI Technol. Rev. PD JUL PY 1997 VL 100 IS 5 BP 6 EP 6 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA XR139 UT WOS:A1997XR13900002 ER PT J AU Reis, VH AF Reis, VH TI The value of a national ignition facility SO TECHNOLOGY REVIEW LA English DT Letter RP Reis, VH (reprint author), US DOE,DEF PROGRAMS,WASHINGTON,DC 20585, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU MASS INST TECHNOL PI CAMBRIDGE PA BUILDING W59, CAMBRIDGE, MA 02139 SN 0040-1692 J9 TECHNOL REV JI Technol. Rev. PD JUL PY 1997 VL 100 IS 5 BP 6 EP 7 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA XR139 UT WOS:A1997XR13900003 ER PT J AU Tarter, CB AF Tarter, CB TI The value of a national ignition facility SO TECHNOLOGY REVIEW LA English DT Letter RP Tarter, CB (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MASS INST TECHNOL PI CAMBRIDGE PA BUILDING W59, CAMBRIDGE, MA 02139 SN 0040-1692 J9 TECHNOL REV JI Technol. Rev. PD JUL PY 1997 VL 100 IS 5 BP 7 EP 7 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA XR139 UT WOS:A1997XR13900004 ER PT J AU Atchity, GJ Ruedenberg, K AF Atchity, GJ Ruedenberg, K TI Global potential energy surfaces for the lowest two (1)A' states of ozone SO THEORETICAL CHEMISTRY ACCOUNTS LA English DT Article DE ozone; potential energy surfaces; conical intersections ID EXCITED-STATES; SCATTERED DATA; PHOTO-DISSOCIATION; PHOTODISSOCIATION; INTERPOLATION; DYNAMICS; INTERSECTIONS; SPECTROSCOPY; BAND; O-3 AB The global features of the potential energy surfaces of the lowest two 'A' states of ozone are established and detailed information is determined for the critical regions. Contour maps are generated on a variety of planes and curved surfaces cutting through the two energy surfaces in various directions to obtain a full understanding of the three-dimensional characteristics of both surfaces. Perimetric internal coordinates are used so that the three atoms are treated on an equal footing. The 1(1)A' state, the ground state, has a ring minimum and three equivalent open minima, all lying in C-2v-restricted coordinate spaces. Direct dissociation to O-2 + O is only possible from the open minima. The lowest energy path from the ring minimum first leads to an open minimum before going to dissociation. The transition states between the ring minimum and the open minima also have C-2v symmetry. Close to these transition states lie the three open minima of the 2(1)A' state, which has no ring minimum. Isomerization between the open minima is highly unlikely in the ground state, but not excluded in the excited state. Both states dissociate into the same state of O-2 + O, namely the ground state O(P-3)+ O-2((3) Sigma(g)(-)) whose energy lies between that of the 1(1)A' End 2(1) A' open minima. There exists an extended. interestingly shaped region in coordinate space in which the two states come very close to each other. It contains an intersection seam between the two states consisting of four branches connected by three knots. Radiationless transitions between the two states can be expected. C1 IOWA STATE UNIV, AMES LAB, US DOE, AMES, IA 50011 USA. IOWA STATE UNIV, DEPT CHEM, AMES, IA 50011 USA. NR 37 TC 39 Z9 39 U1 1 U2 5 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1432-881X J9 THEOR CHEM ACC JI Theor. Chem. Acc. PD JUL PY 1997 VL 96 IS 3 BP 176 EP 194 DI 10.1007/s002140050220 PG 19 WC Chemistry, Physical SC Chemistry GA XR421 UT WOS:A1997XR42100006 ER PT J AU Atchity, GJ Ruedenberg, K Nanayakkara, A AF Atchity, GJ Ruedenberg, K Nanayakkara, A TI The intersection seam between the 1(1)A' and 2(1)A' states of ozone SO THEORETICAL CHEMISTRY ACCOUNTS LA English DT Article DE conical intersection; intersection seam; diabatic states; ozone ID POTENTIAL-ENERGY SURFACES; CONICAL INTERSECTIONS; NONCROSSING RULE; SYMMETRY; POINT AB The intersection seam between the two lowest (1)A' states of ozone has been determined. The potential energy surfaces and the seam are calculated and discussed in perimetric coordinates which exhibit the full three-dimensional symmetry. The seam is shown to form a closed curve which crosses the C-2v-restricted coordinate planes at six points. Three of these correspond to the previously determined intersection, the starting point of the present search. The other three correspond to highly repulsive regions on the potential energy surface where two atoms approach each other to within two-thirds of the O-2 bond length. At the former three points both states have (1)A(1) symmetry, but at the latter three points one state has (1)A(1) symmetry whereas the other has B-1(2) symmetry. Consequently, there exist three additional branches of the intersection seam between these two states. Each of these branches lies entirely in one C-2v-restricted coordinate plane and connects to the previously discussed C-s-seam at one point. The existence of a further intersection seam is established. A novel method for determining intersection points is described. C1 IOWA STATE UNIV,AMES LAB,US DOE,AMES,IA 50011. IOWA STATE UNIV,DEPT CHEM,AMES,IA 50011. NR 20 TC 50 Z9 50 U1 0 U2 5 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 1432-881X J9 THEOR CHEM ACC JI Theor. Chem. Acc. PD JUL PY 1997 VL 96 IS 3 BP 195 EP 204 DI 10.1007/s002140050221 PG 10 WC Chemistry, Physical SC Chemistry GA XR421 UT WOS:A1997XR42100007 ER PT J AU Atchity, GJ Ruedenberg, K AF Atchity, GJ Ruedenberg, K TI Perimetric scale-shape coordinates for triatomic molecules SO THEORETICAL CHEMISTRY ACCOUNTS LA English DT Article DE internal coordinates; triatomic molecules ID SURFACES AB Perimetric nuclear coordinates of a triatomic molecule treat all three nuclei equivalently and are not subject to the triangle conditions. Through an appropriate orthogonal transformation they can be separated into one scale coordinate, viz., the circumference, and two shape coordinates, which are determined by the angles. The parameter space of the shape coordinates is an equilateral triangle. The basic formulas are given and the relationship between points in coordinate space and molecular shapes are elucidated. C1 IOWA STATE UNIV,AMES LAB,US DOE,AMES,IA 50011. IOWA STATE UNIV,DEPT CHEM,AMES,IA 50011. NR 9 TC 9 Z9 9 U1 0 U2 3 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 1432-881X J9 THEOR CHEM ACC JI Theor. Chem. Acc. PD JUL PY 1997 VL 96 IS 3 BP 205 EP 211 DI 10.1007/s002140050222 PG 7 WC Chemistry, Physical SC Chemistry GA XR421 UT WOS:A1997XR42100008 ER PT J AU Wilson, AK Bhattacharyya, MH AF Wilson, AK Bhattacharyya, MH TI Effects of cadmium on bone: An in vivo model for the early response SO TOXICOLOGY AND APPLIED PHARMACOLOGY LA English DT Article ID CALCIUM-DEFICIENT DIET; OCCUPATIONAL EXPOSURE; RESORPTION; MICE; RAT; OSTEOPETROSIS; MACROPHAGE; METABOLISM; CULTURE; WORKERS AB Cadmium (Cd) exposure induces bone resorption in vitro and in vivo that can lead to low bone mass and increased incidence of fracture. We have developed an animal model for following the early skeletal response to Cd. A low-calcium (but not calcium-deficient) diet is used to increase gastrointestinal absorption of calcium so that the endogenous fecal calcium excretion is essentially the total fecal calcium excretion. The bone response is followed by quantitation of stable fecal calcium and does not require a radioactive label. After mice were adjusted to a low-calcium diet, Cd was administered by a single gavage and fecal calcium was monitored to determine the magnitude of the calcium release from bone. Fecal calcium excretion (mu g Ca/hr; mean +/- SE) remained at the background level for 8 hr (13.6 +/- 1.8, n = 18) but increased during the 8- to 24-hr and 24- to 56-hr collection periods (43.8 +/- 6.8, n = 12; 50.75 +/- 3.7, n = 6, respectively). The bone response was transient and dropped to nearly background levels during the 56- to 104-hr collection period. Blood calcium levels were normal throughout the time course. Bone resorption occurred at Cd levels of 7.9 +/- 0.7 mu g/liter blood (mean +/- SE, n = 6), which is in the range of occupational exposure levels. The transient nature of the bone response contrasted to the slow but continuing rise observed in blood Cd levels. These results suggest that a threshold level of Cd is required for a bone response but that chronic levels of Cd in blood do not necessarily indicate the occurrence of continuous active bone resorption. This model can be used to probe early gene changes (prior to the bone response) that may be occurring in response to Cd exposure. (C) 1997 Academic Press. RP Wilson, AK (reprint author), ARGONNE NATL LAB,CTR MECHANIST BIOL & BIOTECHNOL,9700 S CASS AVE,ARGONNE,IL 60439, USA. FU NIEHS NIH HHS [ES04816, ES07398] NR 43 TC 32 Z9 33 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 0041-008X J9 TOXICOL APPL PHARM JI Toxicol. Appl. Pharmacol. PD JUL PY 1997 VL 145 IS 1 BP 68 EP 73 DI 10.1006/taap.1997.8164 PG 6 WC Pharmacology & Pharmacy; Toxicology SC Pharmacology & Pharmacy; Toxicology GA XL859 UT WOS:A1997XL85900008 PM 9221825 ER PT J AU Blau, PJ Oliver, WC Snead, L AF Blau, PJ Oliver, WC Snead, L TI The scanning micro-sclerometer: A new method for scratch hardness mapping SO TRIBOLOGY INTERNATIONAL LA English DT Article; Proceedings Paper CT Meeting on Scratch Testing CY JUN, 1995 CL LONDON, ENGLAND SP Inst Phys, Tribol Grp DE scratch testing; nanoindentation; microscratch; silicon carbide composite; micro-machining AB A new surface engineering research tool, called a scanning micro-sclerometer (SMS), has been developed. It uses nano-indentation technology and a piezoelectric transducer positioning system to generate high-precision scratch patterns on the surfaces of metals and, by monitoring the instantaneous displacement of the stylus tip, can generate scratch hardness and scratching force maps of the surface. A dual-stroke process is used, The first stroke at low load profiles the surface to establish a reference datum and the second pass, in the opposite direction and at higher load, produces the indentation scratch, Examples of micro-scratch hardness mapping experiments, using scratch spacings of 1.0 mu m, on a silicon carbide-based ceramic composite are used to illustrate the capabilities of the SMS. Using end-on fibers in the rectangular stylus scanning area, the difference in scratch hardnesses of the fibers, the matrix, and even the thin carbon coatings in the fiber-matrix interface could be detected. The SMS was originally developed to produce scratch hardness maps, but it is also useful for conducting accurately controlled, single-point micro-machining patterns and in studies of differential material abrasion. (C) 1997 Elsevier Science Ltd. C1 NANO INSTRUMENTS INC,KNOXVILLE,TN 37914. RENSSELAER POLYTECH INST,TROY,NY 12181. RP Blau, PJ (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,POB 2008,OAK RIDGE,TN 37831, USA. NR 12 TC 2 Z9 2 U1 1 U2 2 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0301-679X J9 TRIBOL INT JI Tribol. Int. PD JUL PY 1997 VL 30 IS 7 BP 483 EP 490 DI 10.1016/S0301-679X(97)00011-X PG 8 WC Engineering, Mechanical SC Engineering GA XK297 UT WOS:A1997XK29700004 ER PT J AU Oliver, J Putnam, C AF Oliver, J Putnam, C TI Energy efficiency: Learning how to avoid taking a bath on energy costs SO WATER-ENGINEERING & MANAGEMENT LA English DT Article C1 MACRO INT INC,CALVERTON,MD 20705. RP Oliver, J (reprint author), US DOE,MOTOR CHALLENGE PROGRAM,WASHINGTON,DC 20585, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU SCRANTON GILLETTE COMMUNICATIONS INC PI DES PLAINES PA 380 NORTHWEST HIGHWAY, DES PLAINES, IL 60016 SN 0273-2238 J9 WATER ENG MANAG JI Water Eng. Manage. PD JUL PY 1997 VL 144 IS 7 BP 22 EP 25 PG 4 WC Engineering, Environmental; Water Resources SC Engineering; Water Resources GA XJ735 UT WOS:A1997XJ73500009 ER PT J AU Gray, RH AF Gray, RH TI A description of long-term environmental monitoring and assessment programs at two US Department of Energy sites SO WATER ENVIRONMENT RESEARCH LA English DT Article DE assessment; environment; monitoring; radionuclides; wildlife ID COLUMBIA RIVER; HANFORD AB The U.S. Department of Energy's Hanford Site was established in southeastern Washington during the 1940s to produce plutonium, and the Pantex plant in Texas (used to load conventional ammunition shells and bombs) was rehabilitated in the 1950s to assemble nuclear weapons using the plutonium produced at Hanford. Current concentrations of airborne radionuclides around the perimeters of both sites are below applicable guidelines. Concentrations of radionuclides and nonradiological water quality in the Columbia River at Hanford and radiological and nonradiological water quality in the Ogallala Aquifer beneath the Pantex plant are also in compliance with applicable standards. Foodstuffs irrigated with river water downstream from Hanford show levels of radionuclides similar to those in foodstuffs from control areas. Levels of Cs-137 and Sr-90 in some on-site Hanford wildlife samples and concentrations of radionuclides in soils and vegetation on and off site at both locations are typical of naturally occurring radioactivity and worldwide fallout. The potential dose received by a maximally exposed individual at both sites in 1994 was less than or equal to 0.05 mrem; the average per capita dose was less than or equal to 0.002 mrem. By virtue of its size, restricted access, and conservative use of undeveloped land, the Hanford Site has become a sanctuary for plant and animal populations that have been eliminated from, or greatly reduced on, surrounding agricultural and range lands. The Hanford Reach of the Columbia River and its islands and the Pantex Plant with its playas serve as refuges for raptorial birds and migratory waterfowl. In addition, the Hanford Reach serves as a migration route for several species of salmon, and chinook salmon and steelhead trout spawn there. Bald eagles congregate along the Hanford Reach in the fall and winter to feed on the spawned-out carcasses of salmon and wintering waterfowl. C1 US DOE,OFF HLTH & ENVIRONM,HANFORD SITE,RICHLAND,WA. US DOE,ENVIRONM PROTECT DEPT,PANTEX,TX. NR 36 TC 1 Z9 1 U1 1 U2 8 PU WATER ENVIRONMENT FEDERATION PI ALEXANDRIA PA 601 WYTHE ST, ALEXANDRIA, VA 22314-1994 SN 1061-4303 J9 WATER ENVIRON RES JI Water Environ. Res. PD JUL-AUG PY 1997 VL 69 IS 5 BP 1015 EP 1021 DI 10.2175/106143097X125713 PG 7 WC Engineering, Environmental; Environmental Sciences; Limnology; Water Resources SC Engineering; Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA XM631 UT WOS:A1997XM63100011 ER PT J AU Hemming, CH Bunde, RL Liszewski, MJ Rosentreter, JJ Welhan, J AF Hemming, CH Bunde, RL Liszewski, MJ Rosentreter, JJ Welhan, J TI Effect of experimental technique on the determination of strontium distribution coefficients of a surficial sediment from the Idaho National Engineering Laboratory, Idaho SO WATER RESEARCH LA English DT Article DE strontium; distribution coefficient; Kd; Idaho National Engineering Laboratory; experimental technique ID SORPTION; AQUIFER; SR-90 AB The effect of experimental technique on strontium distribution coefficients (K-d's) was determined as part of an investigation of strontium geochemical transport properties of surficial sediment from the Idaho National Engineering Laboratory, Idaho. The investigation was conducted by the U.S. Geological Survey and Idaho State University, in cooperation with the U.S. Department of Energy. Batch experiments were conducted to quantify the effect of different experimental techniques on experimentally derived strontium K-d's at a fixed pH of 8.0. Combinations of three variables were investigated: method of sample agitation (rotating-mixer and shaker table), ratio of the mass-of-sediment to the volume-of-reaction-solution (1:2 and 1:20), and method of sediment preparation (crushed and non-crushed). Strontium K-d's ranged from 11 to 23 mlg(-1) among all three experimental variables examined. Strontium K-d's were bimodally grouped around 12 and 21 mlg(-1). Among the three experimental variables examined, the mass-to-volume ratio appeared to be the only one that could account for this bimodal distribution. The bimodal distribution of the derived strontium K-d's may. occur because the two different mass-to-volume ratios represent different natural systems. The high mass-to-volume ratio of 1:2 models a natural system, such as an aquifer, in which there is an abundance of favorable sorption sites relative to the amount of strontium in solution. The low mass-to-volume ratio of 1:20 models a natural system, such as a stream, in which the relative amount of strontium in Solution exceeds the favorable surface sorption site concentration. Except for low mass-to-volume ratios of non-crushed sediment using a rotating mixer, the method of agitation and sediment preparation appears to have little influence on derived strontium K-d's. (C) 1997 Elsevier Science Ltd. C1 US GEOL SURVEY,IDAHO FALLS,ID 83403. IDAHO STATE UNIV,DEPT CHEM,POCATELLO,ID 83209. IDAHO STATE UNIV,DEPT GEOL,IDAHO GEOL SURVEY,POCATELLO,ID 83209. NR 17 TC 18 Z9 18 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0043-1354 J9 WATER RES JI Water Res. PD JUL PY 1997 VL 31 IS 7 BP 1629 EP 1636 DI 10.1016/S0043-1354(96)00408-3 PG 8 WC Engineering, Environmental; Environmental Sciences; Water Resources SC Engineering; Environmental Sciences & Ecology; Water Resources GA XE042 UT WOS:A1997XE04200012 ER PT J AU Tidwell, VC Wilson, JL AF Tidwell, VC Wilson, JL TI Laboratory method for investigating permeability upscaling SO WATER RESOURCES RESEARCH LA English DT Article ID HYDRAULIC CONDUCTIVITY; MINIPERMEAMETER; AQUIFERS; ROCKS; SCALE; FLOW AB The purpose of this work is to describe, evaluate, and demonstrate a laboratory-based method for physically investigating permeability upscaling. The method makes use of a simple instrument, the gas permeameter, to acquire rapid, precise, and nondestructive permeability measurements from heterogeneous blocks of dry rock. Critical to investigating permeability upscaling is the ability to acquire data at multiple sample supports subject to consistent boundary conditions and flow geometry. Such measurements, spanning almost 4 orders of magnitude on a per volume basis, are made with the gas permeameter by simply varying the size of the permeameter tip seal. The precision and consistency of measurements made in this way were evaluated using a suite of data collected from blocks of three relatively homogeneous materials: Berea Sandstone and two synthetic rocks. Results suggest that measurement error is small (approximately +/-1% of the measured permeability) and consistent, and measurements made at different sample supports are free from systematic bias. To demonstrate the ability of this method to measure and quantify upscaling processes, limited data sets were collected with four different-sized tip seals from the Berea Sandstone block. Analysis reveals distinct and consistent trends diagnostic of permeability upscaling relating the sample mean (increased), variance (decreased), and semivariogram to increasing sample support. C1 NEW MEXICO INST MIN & TECHNOL,DIV EARTH & ENVIRONM SCI,SOCORRO,NM 87801. RP Tidwell, VC (reprint author), SANDIA NATL LABS,GEOHYDROL DEPT,POB 5800,MS 1324,ALBUQUERQUE,NM 87185, USA. NR 32 TC 50 Z9 51 U1 0 U2 6 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD JUL PY 1997 VL 33 IS 7 BP 1607 EP 1616 DI 10.1029/97WR00804 PG 10 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA XG958 UT WOS:A1997XG95800008 ER PT J AU Veloso, JFCA dosSantos, JMF Conde, CAN Morgado, RE AF Veloso, JFCA dosSantos, JMF Conde, CAN Morgado, RE TI Application of a microstrip gas counter in energy-dispersive x-ray fluorescence analysis SO X-RAY SPECTROMETRY LA English DT Article; Proceedings Paper CT European Conference on Energy Dispersive X-Ray Spectrometry CY JUN 23-29, 1996 CL LISBON, PORTUGAL ID DETECTORS; CHAMBERS AB Performance characteristics of a microstrip gas counter operated as an x-ray fluorescence spectrometer are reported, Gas amplification as a function of microstrip anode-cathode voltage was measured, and the breakdown threshold voltage was determined in pure xenon. The detector temporal stability and the effect of gas purity were assessed, Energy resolution and linearity, detection efficiency and uniformity of spatial response in the 2-60 keV x-ray energy range were determined from the pulse-height distributions of the fluorescence x-ray spectra induced in a variety of single- and multi-element sample materials, Energy resolution similar to that of conventional proportional counters was achieved at 6 keV. (C) 1997 by John Wiley & Sons, Ltd. C1 UNIV COIMBRA,DEPT FIS,P-3000 COIMBRA,PORTUGAL. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RI veloso, joao/J-4478-2013; dos Santos, Joaquim/B-3058-2015; OI Conde, Carlos/0000-0002-1387-2161; Veloso, Joao/0000-0002-7107-7203; dos Santos, Joaquim Marques Ferreira/0000-0002-8841-6523 NR 11 TC 15 Z9 15 U1 0 U2 0 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0049-8246 J9 X-RAY SPECTROM JI X-Ray Spectrom. PD JUL-AUG PY 1997 VL 26 IS 4 BP 237 EP 243 DI 10.1002/(SICI)1097-4539(199707)26:4<237::AID-XRS251>3.3.CO;2-T PG 7 WC Spectroscopy SC Spectroscopy GA XM145 UT WOS:A1997XM14500018 ER PT J AU Kaper, HG Takac, P AF Kaper, HG Takac, P TI An equivalence relation for the Ginzburg-Landau equations of superconductivity SO ZEITSCHRIFT FUR ANGEWANDTE MATHEMATIK UND PHYSIK LA English DT Article DE superconductivity; Ginzburg-Landau equations; gauge invariance; large-time asymptotic behavior ID MODEL AB Gauge invariance is used to establish an equivalence relation between solutions of the time-independent and time-dependent Ginzburg-Landau equations that describe the same physical state of a superconductor. The equivalence relation shows how equilibrium configurations are obtained as large-time asymptotic limits of solutions of the time-dependent Ginzburg-Landau equations. C1 UNIV ROSTOCK,FACHBEREICH MATH,D-18055 ROSTOCK,GERMANY. RP Kaper, HG (reprint author), ARGONNE NATL LAB,DIV MATH & COMP SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 14 TC 5 Z9 5 U1 0 U2 1 PU BIRKHAUSER VERLAG AG PI BASEL PA PO BOX 133 KLOSTERBERG 23, CH-4010 BASEL, SWITZERLAND SN 0044-2275 J9 Z ANGEW MATH PHYS JI Z. Angew. Math. Phys. PD JUL PY 1997 VL 48 IS 4 BP 665 EP 675 DI 10.1007/s000330050054 PG 11 WC Mathematics, Applied SC Mathematics GA XT027 UT WOS:A1997XT02700009 ER PT J AU Breitweg, J Derrick, M Krakauer, D Magill, S Mikunas, D Musgrave, B Repond, J Stanek, R Talaga, RL Yoshida, R Zhang, H Mattingly, MCK Anselmo, F Antonioli, P Bari, G Basile, M Bellagamba, L Boscherini, D Bruni, A Bruni, G Romeo, GC Castellini, G Cifarelli, L Cindolo, F Contin, A Corradi, M DePasquale, S Gialas, I Giusti, P Iacobucci, G Laurenti, G Levi, G Margotti, A Massam, T Nania, R Palmonari, F Pesci, A Polini, A Sartorelli, G Garcia, YZ Zichichi, A Amelung, C Bornheim, A Brock, I Coboken, K Crittenden, J Deffner, R Eckert, M Feld, L Grothe, M Hartmann, H Heinloth, K Heinz, L Hilger, E Jakob, HP Katz, UF Paul, E Pfeiffer, M Rembser, C Stamm, J Wedemeyer, R Bailey, DS CampbellRobson, S Cottingham, WN Foster, B HallWilton, R Hayes, ME Heath, GP Heath, HF Piccioni, D Roff, DG Tapper, RJ Arneodo, M Ayad, R Capua, M Garfagnini, A Iannotti, L Schioppa, M Susinno, G Kim, JY Lee, JH Lim, IT Pac, MY Caldwell, A Cartiglia, N Jing, Z Liu, W Parsons, JA Ritz, S Sampson, S Sciulli, F Straub, PB Zhu, Q Borzemski, P Chwastowski, J Eskreys, A Jakubowski, Z Przybycien, MB Zachara, M Zawiejski, L Adamczyk, L Bednarek, B Jelen, K Kisielewska, D Kowalski, T Przybycien, M RulikowskaZarebska, E Suszycki, L Zajac, J Dulinski, Z Kotanski, A Abbiendi, G Bauerdick, LAT Behrens, U Beier, H Bienlein, JK Cases, G Deppe, O Desler, K Drews, G Fricke, U Gilkinson, DJ Glasman, C Gottlicher, P GrosseKnetter, J Haas, T Hain, W Hasell, D Hessling, H Johnson, KF Kasemann, M Koch, W Kotz, U Kowalski, H Labs, J Lindemann, L Lohr, B Lowe, M Mainusch, J Manczak, O Milewski, J Monteiro, T Ng, JST Notz, D Ohrenberg, K Park, IH Pellegrino, A Pelucchi, F Piotrzkowski, K Roco, M Rohde, M Roldan, J Ryan, JJ Savin, AA Schneekloth, U Schulz, W Selonke, F Surrow, B Tassi, E Voss, T Westphal, D Wolf, G Wollmer, U Youngman, C Zarnecki, AF Zeuner, W Burow, BD Grabosch, HJ Meyer, A Schlenstedt, S Barbagli, G Gallo, E Pelfer, P Maccarrone, G Votano, L Bamberger, A Eisenhardt, S Markun, P Trefzger, T Wolfle, S Bromley, JT Brook, NH Bussey, PJ Doyle, AT Saxon, DH Sinclair, LE Strickland, E Utley, ML Waugh, R Wilson, AS Bohnet, I Gendner, N Holm, U MeyerLarsen, A Salehi, H Wick, K Gladilin, LK Klanner, R Lohrmann, E Poelz, G Schott, W Zetsche, F Bacon, TC Butterworth, I Cole, JE Harris, VL Howell, G Hung, BHY Lamberti, L Long, KR Miller, DB Pavel, N Prinias, A Sedgbeer, JK Sideris, D Whitfield, AF Mallik, U Wang, SM Wu, JT Cloth, P Filges, D Fleck, JI Ishii, T Kuze, M Nakao, M Tokushuku, K Yamada, S Yamazaki, Y An, SH Lee, SB Nam, SW Park, HS Park, SK Barreiro, F Fernandez, JP Graciani, R Hernandez, JM Hervas, L Labarga, L Martinez, M delPeso, J Puga, J Terron, J deTroconiz, JF Corriveau, F Hanna, DS Hartmann, J Hung, LW Lim, JN Murray, WN Ochs, A Riveline, M Stairs, DG StLaurent, M Ullmann, R Tsurugai, T Bashkirov, V Dolgoshein, BA Stifutkin, A Bashindzhagyan, GL Ermolov, PF Golubkov, YA Khein, LA Korotkova, NA Korzhavina, LA Kuzmin, VA Lukina, OY Proskuryakov, AS Shcheglova, LM Shumilin, AV Solomin, AN Zotkin, SA Bokel, C Botje, M Brummer, N Chlebana, F Engelen, J Kooijman, P Kruse, A vanSighem, A Tiecke, H Verkerke, W Vossebeld, J Vreeswijk, M Wiggers, L deWolf, E Acosta, D Bylsma, B Durkin, LS Gilmore, J Ginsburg, CM Kim, CL Ling, TY Nylander, P Romanowski, TA Blaikley, HE Cashmore, RJ CooperSarkar, AM Devenish, RCE Edmonds, JK Harnew, N Lancaster, M McFall, JD Nath, C Noyes, VA Quadt, A Tickner, JR Uijterwaal, H Walczak, R Waters, DS Yip, T Bertolin, A Brugnera, R Carlin, R DalCorso, F Dosselli, U Limentani, S Morandin, M Posocco, M Stanco, L Stroili, R Voci, C Bulmahn, J Feild, RG Oh, BY Okrasinski, JR Whitmore, JJ Iga, Y DAgostini, G Marini, G Nigro, A Raso, M Hart, JC McCubbin, NA Shah, TP Barberis, E Dubbs, T Heusch, C VanHook, M Lockman, W Rahn, JT Sadrozinski, HFW Seiden, A Williams, DC Schwarzer, O Walenta, AH Abramowicz, H Briskin, G Dagan, S Doeker, T Kananov, S Levy, A Abe, T Inuzuka, M Nagano, K Suzuki, I Umemori, K Hamatsu, R Hirose, T Homma, K Kitamura, S Matsushita, T Yamauchi, K Cirio, R Costa, M Ferrero, MI Maselli, S Monaco, V Peroni, C Petrucci, MC Sacchi, R Solano, A Staiano, A Dardo, M Bailey, DC Brkic, M Fagerstroem, CP Hartner, GF Joo, KK Levman, GM Martin, JF Orr, RS Polenz, S Sampson, CR Simmons, D Teuscher, RJ Butterworth, JM Catterall, CD Jones, TW Kaziewicz, PB Lane, JB Saunders, RL Shulman, J Sutton, MR Lu, B Mo, LW Ciborowski, J Grzelak, G Kasprzak, M Muchorowski, K Nowak, RJ Pawlak, JM Pawlak, R Tymieniecka, T Wroblewski, AK Zakrzewski, JA Adamus, M Coldewey, C Eisenberg, Y Hochman, D Karshon, U Revel, D Badgett, WF Chapin, D Cross, R Dasu, S Foudas, C Loveless, RJ Mattingly, S Reeder, DD Smith, WH Vaiciulis, A Wodarczyk, M Bhadra, S Frisken, WR Khakzad, M Schmidke, WB AF Breitweg, J Derrick, M Krakauer, D Magill, S Mikunas, D Musgrave, B Repond, J Stanek, R Talaga, RL Yoshida, R Zhang, H Mattingly, MCK Anselmo, F Antonioli, P Bari, G Basile, M Bellagamba, L Boscherini, D Bruni, A Bruni, G Romeo, GC Castellini, G Cifarelli, L Cindolo, F Contin, A Corradi, M DePasquale, S Gialas, I Giusti, P Iacobucci, G Laurenti, G Levi, G Margotti, A Massam, T Nania, R Palmonari, F Pesci, A Polini, A Sartorelli, G Garcia, YZ Zichichi, A Amelung, C Bornheim, A Brock, I Coboken, K Crittenden, J Deffner, R Eckert, M Feld, L Grothe, M Hartmann, H Heinloth, K Heinz, L Hilger, E Jakob, HP Katz, UF Paul, E Pfeiffer, M Rembser, C Stamm, J Wedemeyer, R Bailey, DS CampbellRobson, S Cottingham, WN Foster, B HallWilton, R Hayes, ME Heath, GP Heath, HF Piccioni, D Roff, DG Tapper, RJ Arneodo, M Ayad, R Capua, M Garfagnini, A Iannotti, L Schioppa, M Susinno, G Kim, JY Lee, JH Lim, IT Pac, MY Caldwell, A Cartiglia, N Jing, Z Liu, W Parsons, JA Ritz, S Sampson, S Sciulli, F Straub, PB Zhu, Q Borzemski, P Chwastowski, J Eskreys, A Jakubowski, Z Przybycien, MB Zachara, M Zawiejski, L Adamczyk, L Bednarek, B Jelen, K Kisielewska, D Kowalski, T Przybycien, M RulikowskaZarebska, E Suszycki, L Zajac, J Dulinski, Z Kotanski, A Abbiendi, G Bauerdick, LAT Behrens, U Beier, H Bienlein, JK Cases, G Deppe, O Desler, K Drews, G Fricke, U Gilkinson, DJ Glasman, C Gottlicher, P GrosseKnetter, J Haas, T Hain, W Hasell, D Hessling, H Johnson, KF Kasemann, M Koch, W Kotz, U Kowalski, H Labs, J Lindemann, L Lohr, B Lowe, M Mainusch, J Manczak, O Milewski, J Monteiro, T Ng, JST Notz, D Ohrenberg, K Park, IH Pellegrino, A Pelucchi, F Piotrzkowski, K Roco, M Rohde, M Roldan, J Ryan, JJ Savin, AA Schneekloth, U Schulz, W Selonke, F Surrow, B Tassi, E Voss, T Westphal, D Wolf, G Wollmer, U Youngman, C Zarnecki, AF Zeuner, W Burow, BD Grabosch, HJ Meyer, A Schlenstedt, S Barbagli, G Gallo, E Pelfer, P Maccarrone, G Votano, L Bamberger, A Eisenhardt, S Markun, P Trefzger, T Wolfle, S Bromley, JT Brook, NH Bussey, PJ Doyle, AT Saxon, DH Sinclair, LE Strickland, E Utley, ML Waugh, R Wilson, AS Bohnet, I Gendner, N Holm, U MeyerLarsen, A Salehi, H Wick, K Gladilin, LK Klanner, R Lohrmann, E Poelz, G Schott, W Zetsche, F Bacon, TC Butterworth, I Cole, JE Harris, VL Howell, G Hung, BHY Lamberti, L Long, KR Miller, DB Pavel, N Prinias, A Sedgbeer, JK Sideris, D Whitfield, AF Mallik, U Wang, SM Wu, JT Cloth, P Filges, D Fleck, JI Ishii, T Kuze, M Nakao, M Tokushuku, K Yamada, S Yamazaki, Y An, SH Lee, SB Nam, SW Park, HS Park, SK Barreiro, F Fernandez, JP Graciani, R Hernandez, JM Hervas, L Labarga, L Martinez, M delPeso, J Puga, J Terron, J deTroconiz, JF Corriveau, F Hanna, DS Hartmann, J Hung, LW Lim, JN Murray, WN Ochs, A Riveline, M Stairs, DG StLaurent, M Ullmann, R Tsurugai, T Bashkirov, V Dolgoshein, BA Stifutkin, A Bashindzhagyan, GL Ermolov, PF Golubkov, YA Khein, LA Korotkova, NA Korzhavina, LA Kuzmin, VA Lukina, OY Proskuryakov, AS Shcheglova, LM Shumilin, AV Solomin, AN Zotkin, SA Bokel, C Botje, M Brummer, N Chlebana, F Engelen, J Kooijman, P Kruse, A vanSighem, A Tiecke, H Verkerke, W Vossebeld, J Vreeswijk, M Wiggers, L deWolf, E Acosta, D Bylsma, B Durkin, LS Gilmore, J Ginsburg, CM Kim, CL Ling, TY Nylander, P Romanowski, TA Blaikley, HE Cashmore, RJ CooperSarkar, AM Devenish, RCE Edmonds, JK Harnew, N Lancaster, M McFall, JD Nath, C Noyes, VA Quadt, A Tickner, JR Uijterwaal, H Walczak, R Waters, DS Yip, T Bertolin, A Brugnera, R Carlin, R DalCorso, F Dosselli, U Limentani, S Morandin, M Posocco, M Stanco, L Stroili, R Voci, C Bulmahn, J Feild, RG Oh, BY Okrasinski, JR Whitmore, JJ Iga, Y DAgostini, G Marini, G Nigro, A Raso, M Hart, JC McCubbin, NA Shah, TP Barberis, E Dubbs, T Heusch, C VanHook, M Lockman, W Rahn, JT Sadrozinski, HFW Seiden, A Williams, DC Schwarzer, O Walenta, AH Abramowicz, H Briskin, G Dagan, S Doeker, T Kananov, S Levy, A Abe, T Inuzuka, M Nagano, K Suzuki, I Umemori, K Hamatsu, R Hirose, T Homma, K Kitamura, S Matsushita, T Yamauchi, K Cirio, R Costa, M Ferrero, MI Maselli, S Monaco, V Peroni, C Petrucci, MC Sacchi, R Solano, A Staiano, A Dardo, M Bailey, DC Brkic, M Fagerstroem, CP Hartner, GF Joo, KK Levman, GM Martin, JF Orr, RS Polenz, S Sampson, CR Simmons, D Teuscher, RJ Butterworth, JM Catterall, CD Jones, TW Kaziewicz, PB Lane, JB Saunders, RL Shulman, J Sutton, MR Lu, B Mo, LW Ciborowski, J Grzelak, G Kasprzak, M Muchorowski, K Nowak, RJ Pawlak, JM Pawlak, R Tymieniecka, T Wroblewski, AK Zakrzewski, JA Adamus, M Coldewey, C Eisenberg, Y Hochman, D Karshon, U Revel, D Badgett, WF Chapin, D Cross, R Dasu, S Foudas, C Loveless, RJ Mattingly, S Reeder, DD Smith, WH Vaiciulis, A Wodarczyk, M Bhadra, S Frisken, WR Khakzad, M Schmidke, WB TI Study of photon dissociation in diffractive photoproduction at HERA SO ZEITSCHRIFT FUR PHYSIK C-PARTICLES AND FIELDS LA English DT Article ID ZEUS BARREL CALORIMETER; OF-MASS ENERGY; MONTE-CARLO; HADRONIC PROCESSES; CROSS-SECTION; DISTRIBUTIONS; CONSTRUCTION; ROOT-S=546 AB Diffractive dissociation of quasi-real photons at a photon-proton centre of mass energy of W approximate to 200 GeV is studied with the ZEUS detector at HERA. The process under consideration is gamma p --> XN, where X is the diffractively dissociated photon system of mass M-X and N is either a proton or a nucleonic system with mass M-N < 2 GeV. The cross section for this process in the interval 3 < M-X < 24 GeV relative to the total photoproduction cross section was measured to be sigma(D)(partial)/sigma(tot) = 6.2 +/- 0.2(stat) +/- 1.4(syst)%. After extrapolating this result to the mass interval of m(phi)(2) < M-X(2) < 0.05W(2) and correcting it for proton dissociation, the fraction of the total cross section attributed to single diffractive photon dissociation, gamma p --> Xp, is found to be sigma(SD)/sigma(tot) = 13.3 +/- 0.5(stat) +/- 3.6(syst)%. The mass spectrum of the dissociated photon system in the interval 8 < M-X < 24 GeV can be described by the triple pomeron (IP IP IP) diagram with an effective pomeron intercept of alpha(IP)(0) = 1.12 +/- 0.04(stat) +/- 0.08(syst). The cross section for photon dissociation in the range 3 < Mr < 8 GeV is significantly higher than that expected from the triple pomeron amplitude describing the region 8 < Mr < 24 GeV. Assuming that this discrepancy is due to a pomeron-pomeron-reggeon (IP IP IR term, its contribution to the diffractive cross section in the interval 3 < Mr < 24 GeV is estimated to be f(IP IP IR) = 26 +/- 3(stat) +/- 12(syst)%. C1 ANDREWS UNIV, BERRIEN SPRINGS, MI 49104 USA. UNIV BOLOGNA, BOLOGNA, ITALY. IST NAZL FIS NUCL, I-40126 BOLOGNA, ITALY. UNIV BONN, INST PHYS, D-5300 BONN, GERMANY. UNIV BRISTOL, HH WILLS PHYS LAB, BRISTOL BS8 1TL, AVON, ENGLAND. UNIV CALABRIA, DEPT PHYS, I-87036 COSENZA, ITALY. IST NAZL FIS NUCL, COSENZA, ITALY. CHONNAM NATL UNIV, KWANGJU, SOUTH KOREA. COLUMBIA UNIV, NEVIS LABS, IRVINGTON, NY USA. INST NUCL PHYS, KRAKOW, POLAND. ACAD MIN & MET, FAC PHYS & NUCL TECHNIQUES, KRAKOW, POLAND. JAGIELLONIAN UNIV, DEPT PHYS, KRAKOW, POLAND. DESY, HAMBURG, GERMANY. IFH ZEUTHEN, DESY, ZEUTHEN, GERMANY. UNIV FLORENCE, FLORENCE, ITALY. IST NAZL FIS NUCL, I-50125 FLORENCE, ITALY. IST NAZL FIS NUCL, LAB NAZL FRASCATI, I-00044 FRASCATI, ITALY. UNIV FREIBURG, FAK PHYS, D-7800 FREIBURG, GERMANY. UNIV GLASGOW, DEPT PHYS & ASTRON, GLASGOW, LANARK, SCOTLAND. UNIV HAMBURG, INST EXPT PHYS 1, HAMBURG, GERMANY. UNIV HAMBURG, INST EXPT PHYS 2, D-2000 HAMBURG, GERMANY. UNIV LONDON IMPERIAL COLL SCI TECHNOL & MED, HIGH ENERGY NUCL PHYS GRP, LONDON, ENGLAND. UNIV IOWA, DEPT PHYS & ASTRON, IOWA CITY, IA 52242 USA. FORSCHUNGSZENTRUM JULICH, FORSCHUNGSZENTRUM, INST KERNPHYS, D-5170 JULICH, GERMANY. NATL LAB HIGH ENERGY PHYS, KEK, INST PARTICLE & NUCL STUDIES, TSUKUBA, IBARAKI 305, JAPAN. KOREA UNIV, SEOUL 136701, SOUTH KOREA. UNIV AUTONOMA MADRID, DEPT FIS TEOR, MADRID, SPAIN. MCGILL UNIV, DEPT PHYS, MONTREAL, PQ, CANADA. MOSCOW ENGN PHYS INST, Moscow, RUSSIA. MOSCOW MV LOMONOSOV STATE UNIV, INST NUCL PHYS, MOSCOW, RUSSIA. NIKHEF, AMSTERDAM, NETHERLANDS. UNIV AMSTERDAM, AMSTERDAM, NETHERLANDS. OHIO STATE UNIV, DEPT PHYS, COLUMBUS, OH 43210 USA. UNIV OXFORD, DEPT PHYS, OXFORD, ENGLAND. UNIV PADUA, DIPARTIMENTO FIS, PADUA, ITALY. IST NAZL FIS NUCL, PADUA, ITALY. PENN STATE UNIV, DEPT PHYS, UNIVERSITY PK, PA 16802 USA. POLYTECH UNIV, SAGAMIHARA, KANAGAWA, JAPAN. UNIV ROMA LA SAPIENZA, DIPARTIMENTO FIS, I-00185 ROME, ITALY. IST NAZL FIS NUCL, ROME, ITALY. RUTHERFORD APPLETON LAB, DIDCOT OX11 0QX, OXON, ENGLAND. UNIV CALIF SANTA CRUZ, SANTA CRUZ, CA 95064 USA. UNIV GESAMTHSCH SIEGEN, FACHBEREICH PHYS, D-5900 SIEGEN, GERMANY. TEL AVIV UNIV, SCH PHYS, RAYMOND & BEVERLY SACKLER FAC EXACT SCI, IL-69978 TEL AVIV, ISRAEL. UNIV TOKYO, DEPT PHYS, TOKYO 113, JAPAN. TOKYO METROPOLITAN UNIV, DEPT PHYS, TOKYO, JAPAN. UNIV TURIN, DIPARTIMENTO FIS SPERIMENTALE, TURIN, ITALY. IST NAZL FIS NUCL, I-10125 TURIN, ITALY. UNIV TURIN, FAC SCI 2, TURIN, ITALY. UNIV TORONTO, DEPT PHYS, TORONTO, ON, CANADA. UCL, DEPT PHYS & ASTRON, LONDON, ENGLAND. VIRGINIA POLYTECH INST & STATE UNIV, DEPT PHYS, BLACKSBURG, VA 24061 USA. WARSAW UNIV, INST EXPT PHYS, WARSAW, POLAND. INST NUCL STUDIES, PL-00681 WARSAW, POLAND. WEIZMANN INST SCI, DEPT NUCL PHYS, IL-76100 REHOVOT, ISRAEL. UNIV WISCONSIN, DEPT PHYS, MADISON, WI 53706 USA. YORK UNIV, DEPT PHYS, N YORK, ON M3J 1P3, CANADA. CNR, IROE, I-50127 FLORENCE, ITALY. RP Breitweg, J (reprint author), ARGONNE NATL LAB, 9700 S CASS AVE, ARGONNE, IL 60439 USA. RI Solomin, Anatoly/C-3072-2016; Graciani Diaz, Ricardo/I-5152-2016; Capua, Marcella/A-8549-2015; Gladilin, Leonid/B-5226-2011; Bashkirov, Vladimir/A-4818-2008; De Pasquale, Salvatore/B-9165-2008; Lancaster, Mark/C-1693-2008; Doyle, Anthony/C-5889-2009; Golubkov, Yury/E-1643-2012; Proskuryakov, Alexander/J-6166-2012; Katz, Uli/E-1925-2013; Wiggers, Leo/B-5218-2015; Hernandez Calama, Jose Maria/H-9127-2015; Tassi, Enrico/K-3958-2015; Morandin, Mauro/A-3308-2016 OI Graciani Diaz, Ricardo/0000-0001-7166-5198; Castellini, Guido/0000-0002-0177-0643; Kasemann, Matthias/0000-0002-0429-2448; Capua, Marcella/0000-0002-2443-6525; Arneodo, Michele/0000-0002-7790-7132; Lancaster, Mark/0000-0002-8872-7292; Abbiendi, Giovanni/0000-0003-4499-7562; Utley, Martin/0000-0001-9928-1516; Gladilin, Leonid/0000-0001-9422-8636; De Pasquale, Salvatore/0000-0001-9236-0748; Doyle, Anthony/0000-0001-6322-6195; Katz, Uli/0000-0002-7063-4418; Wiggers, Leo/0000-0003-1060-0520; Hernandez Calama, Jose Maria/0000-0001-6436-7547; Morandin, Mauro/0000-0003-4708-4240 NR 44 TC 41 Z9 41 U1 0 U2 4 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0170-9739 J9 Z PHYS C PART FIELDS JI Z. Phys. C-Part. Fields PD JUL PY 1997 VL 75 IS 3 BP 421 EP 435 DI 10.1007/s002880050485 PG 15 WC Physics, Particles & Fields SC Physics GA XP365 UT WOS:A1997XP36500004 ER PT J AU Wong, CY Chatterjee, L AF Wong, CY Chatterjee, L TI Effects of screening on quark-antiquark cross sections in quark-gluon plasma SO ZEITSCHRIFT FUR PHYSIK C-PARTICLES AND FIELDS LA English DT Article ID FINITE TEMPERATURE; NUCLEAR COLLISIONS; CHARM PRODUCTION; QCD; DILEPTON; QUARK-MATTER-95; DISTRIBUTIONS; SUPPRESSION AB Lowest-order cross sections for q (q) over bar production and annihilation can be approximately corrected for higher-order QCD effects by using a corrective K-factor. For energies where quark masses cannot be ignored, the K-factor is dominated by the wave function distortion arising from the initial- or final-state interaction between the quark and the antiquark. We evaluate this K-factor for q (q) over bar production and annihilation in a quark-gluon plasma by taking into account the effects of Debye screening through a color-Yukawa potential. We present the corrective K-factor as a function of dimensionless parameters which may find applications in other systems involving attractive or repulsive Yukawa interactions. Prominent peaks of the K-factor occur for an attractive q-(q) over bar, color-Yukawa interaction with Debye screening lengths of 0.835 and 3.23 times the Bohr radius, corresponding to two lowest s-wave q (q) over bar bound states moving into the continuum to become q (q) over bar resonances as the Debye screening length decreases. These resonances, especially the c (c) over bar and the b (b) over bar resonances, may be utilized to study the quark-gluon plasma by examining the systematics of the temperature dependence of heavy-quark pair production just above the threshold. C1 UNIV TENNESSEE,DEPT PHYS,KNOXVILLE,TN 37996. RP Wong, CY (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. OI Wong, Cheuk-Yin/0000-0001-8223-0659 NR 71 TC 9 Z9 9 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0170-9739 J9 Z PHYS C PART FIELDS JI Z. Phys. C-Part. Fields PD JUL PY 1997 VL 75 IS 3 BP 523 EP 534 DI 10.1007/s002880050496 PG 12 WC Physics, Particles & Fields SC Physics GA XP365 UT WOS:A1997XP36500015 ER PT J AU Bellaiche, L Wei, SH Zunger, A AF Bellaiche, L Wei, SH Zunger, A TI Band gaps of GaPN and GaAsN alloys SO APPLIED PHYSICS LETTERS LA English DT Article ID SPECIAL QUASIRANDOM STRUCTURES; GAAS1-XNX; STABILITY; NITROGEN AB The importance of atomic relaxations, chemical disorder, and epitaxial constraints on the band gap of random, anion-mixed nitride alloys GaPN and GaAsN have been investigated, via pseudopotentials calculation. It has been demonstrated that simple approximations such as the virtual crystal approximation, or the use of high-symmetry ordered structure to mimic a random alloy, or the neglect of atomic displacements, are inadequate. It is found that a fully relaxed, large supercell calculation reproduces well the experimental band gaps of GaPN and GaAsN films. (C) 1997 American Institute of Physics. RP NATL RENEWABLE ENERGY LAB, GOLDEN, CO 80401 USA. RI Zunger, Alex/A-6733-2013 NR 21 TC 144 Z9 150 U1 1 U2 20 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 JUN 30 PY 1997 VL 70 IS 26 BP 3558 EP 3560 DI 10.1063/1.119232 PG 3 WC Physics, Applied SC Physics GA XG499 UT WOS:A1997XG49900024 ER PT J AU Cooke, DW Bennett, BL Farnum, EH Hults, WL Muenchausen, RE Smith, JL AF Cooke, DW Bennett, BL Farnum, EH Hults, WL Muenchausen, RE Smith, JL TI Thermally stimulated luminescence from x-irradiated porous silicon SO APPLIED PHYSICS LETTERS LA English DT Article AB We have measured thermally stimulated luminescence from light-emitting porous silicon that has been x irradiated at room temperature and heated to 400 degrees C. The glow curve exhibits peaks at 103, 155, 219, and 271 degrees C, with additional maxima occurring above 400 degrees C. Each of the peaks emits similar emission spectra characterized by a band with a maximum near 720 nm and 0.39 eV full width at half-maximum. Following x irradiation at room temperature, the sample exhibits well-known photoluminescence, but after heating to 400 degrees C, the loss of hydrogen renders the sample nonphotoluminescent. However, thermally stimulated luminescence can be repeatedly induced. Observation of thermally stimulated luminescence is unambiguous evidence for the existence of an insulating surface layer on porous silicon. (C) 1997 American Institute of Physics. RP Cooke, DW (reprint author), LOS ALAMOS NATL LAB,DIV MAT SCI & TECHNOL,LOS ALAMOS,NM 87545, USA. NR 12 TC 55 Z9 58 U1 1 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 JUN 30 PY 1997 VL 70 IS 26 BP 3594 EP 3596 DI 10.1063/1.119243 PG 3 WC Physics, Applied SC Physics GA XG499 UT WOS:A1997XG49900036 ER PT J AU Hou, HQ Hammons, BE Chui, HC AF Hou, HQ Hammons, BE Chui, HC TI Carbon doping and etching of AlxGa1-xAs (0<=x<=1) with carbon tetrachloride in metalorganic vapor phase epitaxy SO APPLIED PHYSICS LETTERS LA English DT Article ID GAAS; DEPOSITION; PRECURSORS; CCL4 AB Carbon doping and the parasitic growth-rate reduction with carbon-tetrachloride (CCl4) in AlxGa1-xAs was studied in the entire Al composition range for metalorganic vapor phase epitaxial growth. The doping efficiency in AlGaAs was found to increase by two orders of magnitude when the Al composition in AlxGa1-xAs changed from 0 to 1. The parasitic growth rate reduction, however, decreased by a factor of 15 when x changed from 0 to 1. This reduction of growth rate was confirmed to be caused by the etching of the material from the surface by Cl radicals cracked from CCl4. This strong compositional selectivity of the doping and etching has potential implications for lateral definition of growth on patterned surfaces. The doping and etching behaviors were also studied as a function of the growth temperature. (C) 1997 American Institute of Physics. RP Hou, HQ (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 10 TC 11 Z9 11 U1 0 U2 3 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 JUN 30 PY 1997 VL 70 IS 26 BP 3600 EP 3602 DI 10.1063/1.119245 PG 3 WC Physics, Applied SC Physics GA XG499 UT WOS:A1997XG49900038 ER PT J AU Jaworska, JS Rose, KA Brenkert, AL AF Jaworska, JS Rose, KA Brenkert, AL TI Individual-based modeling of PCBs effects on young-of-the-year largemouth bass in southeastern USA reservoirs SO ECOLOGICAL MODELLING LA English DT Article DE largemouth bass; individual-based model; population dynamics; polychlorinated biphenyls; contaminant effects ID POLYCHLORINATED-BIPHENYLS PCBS; TOXIC EQUIVALENCY FACTORS; STRIPED BASS; SMALLMOUTH BASS; RAINBOW-TROUT; FISH EGGS; GROWTH; POPULATION; SURVIVAL; TEMPERATURE AB Effects of polychlorinated biphenyls (PCBs) on young-of-the-year (YOY) largemouth bass (Micropterus salmoides) are simulated using an individual-based population model. The model simulates the daily development, growth, and survival of largemouth bass from eggs to the end of their first growing season (October 15) in a single, well-mixed box. The model was configured for southeastern USA reservoirs, mostly using data from two Tennessee River impoundments. PCBs exposure levels are expressed as tetrachlorodibenzo-p-dioxin (TCDD) concentrations in largemouth bass tissue. PCBs effects of increased mortality and reduced growth (via decreased feeding and increased metabolic rate) are imposed on modelled individuals dependent on specified exposure concentrations. Monte Carlo simulation is used to reflect variation in model inputs and express model predictions as probability distributions. The following five model predictions of largemouth bass were analyzed: number density (number/ha), biomass density (kg/ha), mean length (cm), and mean condition factor (K): all on October 15, and survivorship (fraction of eggs surviving to October 15). PCBs concentrations between 0 and 20 ppm were simulated. Predicted bass number density and biomass density increased with increasing spawner density and for each spawner density, decreased with increasing PCBs levels. Both number density and biomass density show a leveling off with increasing spawner density, implying density-dependence (due to bass consumption reducing prey densities) was operating. PCBs effects were apparent but small relative to natural variation in model predictions. Number density, biomass density, mean condition factor K, and survivorship all decreased, and mean length slightly increased, with increasing PCBs levels. Predicted PCBs effects for a chronically-exposed population (fewer spawners) were less at low exposure levels and greater at high exposure levels than those for an initially-healthy population. Field-based comparisons of YOY densities have a low power for distinguishing PCBs effects from natural interannual variability. While the direct effects of PCBs were relatively small, PCBs exposure may increase the risk of populations to natural and other anthropogenic stresses. Some caution should be used when short-term predictions are used to assess long-term consequences of contaminant exposure. Accurate prediction of PCBs effects require realistic representation of YOY largemouth bass growth rates and better methods for estimating exposure in nature. (C) 1997 Elsevier Science B.V. C1 OAK RIDGE NATL LAB,DIV ENVIRONM SCI,OAK RIDGE,TN 37831. NR 96 TC 16 Z9 17 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3800 J9 ECOL MODEL JI Ecol. Model. PD JUN 30 PY 1997 VL 99 IS 2-3 BP 113 EP 135 DI 10.1016/S0304-3800(96)01943-6 PG 23 WC Ecology SC Environmental Sciences & Ecology GA XC437 UT WOS:A1997XC43700002 ER PT J AU Mulholland, PJ Best, GR Coutant, CC Hornberger, GM Meyer, JL Robinson, PJ Stenberg, JR Turner, RE VeraHerrera, F Wetzel, RG AF Mulholland, PJ Best, GR Coutant, CC Hornberger, GM Meyer, JL Robinson, PJ Stenberg, JR Turner, RE VeraHerrera, F Wetzel, RG TI Effects of climate change on freshwater ecosystems of the south-eastern United States and the Gulf Coast of Mexico SO HYDROLOGICAL PROCESSES LA English DT Article; Proceedings Paper CT Symposium on Regional Assessment of Freshwater Ecosystems and Climate Change in North America CY OCT 24-26, 1994 CL LEESBURG, VA SP Amer Soc Limnol & Oceanog, N Amer Benthol Soc, US EPA, US Geol Survey DE climate change; freshwater ecosystems; south-eastern USA; Eastern Mexico; climate models; anthropogenic stress ID CARBON-DIOXIDE; WATER; FLORIDA; TEMPERATURE; NITROGEN; FOREST; IMPACT; TRENDS; FISH; USA AB The south-eastern United States and Gulf Coast of Mexico is physiographically diverse, although dominated by a broad coastal plain. Much of the region has a humid, warm temperate climate with little seasonality in precipitation but strong seasonality in runoff owing to high rates of summer evapotranspiration. The climate of southern Florida and eastern Mexico is subtropical with a distinct summer wet season and winter dry season. Regional climate models suggest that climate change resulting from a doubling of the pre-industrial levels of atmospheric CO2 may increase annual air temperatures by 3-4 degrees C. Changes in precipitation are highly uncertain, but the most probable scenario shows higher levels over all but the northern, interior portions of the region, with increases primarily occurring in summer and occurring as more intense or clustered storms. Despite the increases in precipitation, runoff is likely to decline over much of the region owing to increases in evapotranspiration exceeding increases in precipitation. Only in Florida and the Gulf Coast areas of the US and Mexico are precipitation increases likely to exceed evapotranspiration increases, producing an increase in runoff. However, increases in storm intensity and clustering are likely to result in more extreme hydrographs, with larger peaks in flow but lower baseflows and longer periods of drought. The ecological effects of climate change on freshwaters of the region include: (1) a general increase in rates of primary production, organic matter decomposition and nutrient cycling as a result of higher temperatures and longer growing seasons: (2) reduction in habitat for cool water species, particularly fish and macroinvertebrates in Appalachian streams; (3) reduction in water quality and in suitable habitat in summer owing to lower baseflows and intensification of the temperature-dissolved oxygen squeeze in many rivers and reservoirs; (4) reduction in organic matter storage and loss of organisms during more intense flushing events in some streams and wetlands; (5) shorter periods of inundation of riparian wetlands and greater drying of wetland soils, particularly in northern and inland areas; (6) expansion of subtropical species northwards, including several non-native nuisance species currently confined to southern Florida; (7) expansion of wetlands in Florida and coastal Mexico, but increase in eutrophication of Florida lakes as a result of greater runoff from urban and agricultural areas; and (8) changes in the flushing rate of estuaries that would alter their salinity regimes, stratification and water quality as well as influence productivity in the Gulf of Mexico. Many of the expected climate change effects will exacerbate current anthropogenic stresses on the region's freshwater systems, including increasing demands for water, increasing waste heat loadings and land use changes that alter the quantity and quality of runoff to streams and reservoirs. Research is needed especially in several critical areas: long-term monitoring of key hydrological, chemical and biological properties (particularly water balances in small, forested catchments and temperature-sensitive species); experimental studies of the effects of warming on organisms and ecosystem processes under realistic conditions (e.g. in situ heating experiments): studies of the effects of natural hydrological variation on biological communities; and assessment of the effects of water management activities on organisms and ecosystem processes, including development and testing of management and restoration strategies designed to counteract changes in climate. (C) 1997 by John Wiley & Sons, Ltd. RP Mulholland, PJ (reprint author), OAK RIDGE NATL LAB,DIV ENVIRONM SCI,POB 2008,OAK RIDGE,TN 37831, USA. RI Mulholland, Patrick/C-3142-2012 NR 79 TC 128 Z9 133 U1 20 U2 165 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0885-6087 J9 HYDROL PROCESS JI Hydrol. Process. PD JUN 30 PY 1997 VL 11 IS 8 BP 949 EP 970 PG 22 WC Water Resources SC Water Resources GA XL947 UT WOS:A1997XL94700007 ER PT J AU Zocher, MA Groves, SE Allen, DH AF Zocher, MA Groves, SE Allen, DH TI A three-dimensional finite element formulation for thermoviscoelastic orthotropic media SO INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING LA English DT Article DE finite element method; viscoelasticity; incremental constitutive law ID VISCOELASTIC ANALYSIS; LAMINATED COMPOSITES; BEHAVIOR; STRESS AB This paper is concerned with the development of a numerical algorithm for the solution of the uncoupled, quasistatic initial/boundary value problem involving orthotropic linear viscoelastic media undergoing thermal and/or mechanical deformation. The constitutive equations, expressed in integral form involving the relaxation moduli, are transformed into an incremental algebraic form prior to development of the finite element formulation. This incrementalization is accomplished inclosed form and results in a recursive relationship which leads to the need of solving a simple set of linear algebraic equations only for the extraction of the finite element solution. Use is made of a Dirichlet-Prony series representation of the relaxation moduli in order to derive the recursive relationship and thereby eliminate the storage problem that arises when dealing with materials possessing memory. Three illustrative example problems are included to demonstrate the method. (C) 1997 by John Wiley & Sons, Ltd. C1 TEXAS A&M UNIV, CTR MECH COMPOSITES, COLLEGE STN, TX 77840 USA. RP LAWRENCE LIVERMORE NATL LAB, POB 808, L-342, LIVERMORE, CA 94551 USA. NR 48 TC 99 Z9 100 U1 0 U2 14 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0029-5981 EI 1097-0207 J9 INT J NUMER METH ENG JI Int. J. Numer. Methods Eng. PD JUN 30 PY 1997 VL 40 IS 12 BP 2267 EP 2288 DI 10.1002/(SICI)1097-0207(19970630)40:12<2267::AID-NME156>3.0.CO;2-P PG 22 WC Engineering, Multidisciplinary; Mathematics, Interdisciplinary Applications SC Engineering; Mathematics GA XE111 UT WOS:A1997XE11100008 ER PT J AU Gartling, DK Sackinger, PA AF Gartling, DK Sackinger, PA TI Finite element simulation of vacuum arc remelting SO INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS LA English DT Article; Proceedings Paper CT 3rd US/Japan Symposium on Finite Element Methods in Large-Scale Computational Fluid Dynamics CY APR 01-03, 1996 CL UNIV MINNESOTA, MINNEAPOLIS, MN SP Univ Minnesota, Army High Performance Comp Res Ctr, Dept Aerosp Engn & Mech, Univ Minnesota, Supercomp Inst HO UNIV MINNESOTA DE viscous flow; solidification; electromagnetics; finite element ID DENDRITIC SOLIDIFICATION; CONVECTION; SYSTEMS; METAL; FLOW AB Vacuum are remelting is a process for producing homogeneous ingots of reactive and macrosegregation-sensitive alloys. A mathematical model of the transport phenomena in the ingot melt is presented together with a discussion of the various simplifying assumptions and approximations that make the problem tractable, with particular attention on transport in the interdendritic mushy zone and on the magnetohydrodynamics. The finite element method is used to discretize the equations for the non-isothermal how problem and the quasi-static electromagnetic problem. Coupling of the finite element solutions for the two field problems is accomplished using the Parallel Virtual Machine software. An analysis of the fluid flow and heat transport in the melt pool of the solidifying ingot shows some of the factors that influence ingot quality during quasi-steady growth conditions. (C) 1997 by John Wiley & Sons, Ltd. RP Gartling, DK (reprint author), SANDIA NATL LABS,ENGN SCI CTR,MS 08276,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 30 TC 3 Z9 3 U1 1 U2 4 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0271-2091 J9 INT J NUMER METH FL JI Int. J. Numer. Methods Fluids PD JUN 30 PY 1997 VL 24 IS 12 BP 1271 EP 1289 DI 10.1002/(SICI)1097-0363(199706)24:12<1271::AID-FLD559>3.0.CO;2-# PG 23 WC Computer Science, Interdisciplinary Applications; Mathematics, Interdisciplinary Applications; Mechanics; Physics, Fluids & Plasmas SC Computer Science; Mathematics; Mechanics; Physics GA XH170 UT WOS:A1997XH17000003 ER PT J AU Londono, JD Wignall, GD AF Londono, JD Wignall, GD TI The Flory-Huggins interaction parameter in blends of polystyrene and poly(p-methylstyrene) by small-angle neutron scattering SO MACROMOLECULES LA English DT Article ID MOLECULAR-WEIGHT POLYSTYRENE; DILUTE POLYMER-SOLUTIONS; PHASE-BEHAVIOR; THERMODYNAMICS; DEPENDENCE; MIXTURES; CHAIN AB Blends of polystyrene and poly(p-methylstyrene) (PPMS) were studied by small-angle neutron scattering. Doubling the molecular weight of the PPMS component had no effect on the Flory-Huggins interaction parameter, chi, as determined from the scattering measurements. The temperature dependence of chi is presented also. RP Londono, JD (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. OI Wignall, George/0000-0002-3876-3244 NR 26 TC 15 Z9 15 U1 1 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD JUN 30 PY 1997 VL 30 IS 13 BP 3821 EP 3824 DI 10.1021/ma970070z PG 4 WC Polymer Science SC Polymer Science GA XH723 UT WOS:A1997XH72300015 ER PT J AU Kent, MS Saunders, RS Nelson, GC Small, JH Wong, APY Smith, GS Majewski, J AF Kent, MS Saunders, RS Nelson, GC Small, JH Wong, APY Smith, GS Majewski, J TI Adsorbed monolayers based on functionalized diblock copolymers SO MACROMOLECULES LA English DT Article ID LANGMUIR-BLODGETT MULTILAYERS; BLOCK-COPOLYMERS; INFRARED-SPECTROSCOPY; ADSORPTION; BEHAVIOR; SURFACES; TOLUENE; CHAINS C1 ARGONNE NATL LAB, ARGONNE, IL 60439 USA. LOS ALAMOS NATL LAB, LOS ALAMOS, NM 87544 USA. RP Kent, MS (reprint author), SANDIA NATL LABS, POB 5800, ALBUQUERQUE, NM 87185 USA. RI Lujan Center, LANL/G-4896-2012 NR 28 TC 5 Z9 6 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD JUN 30 PY 1997 VL 30 IS 13 BP 3942 EP 3945 DI 10.1021/ma961648s PG 4 WC Polymer Science SC Polymer Science GA XH723 UT WOS:A1997XH72300035 ER PT J AU Osman, TM Lewandowski, JJ Lesuer, DR AF Osman, TM Lewandowski, JJ Lesuer, DR TI The fracture resistance of layered DRA materials: influence of laminae thickness SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE aluminum; fracture resistance; laminae thickness ID DISCONTINUOUSLY REINFORCED ALUMINUM; SUPERIMPOSED HYDROSTATIC-PRESSURE; METAL MATRIX COMPOSITE; DEFORMATION; TOUGHNESS; MICROSTRUCTURE; BEHAVIOR; AL AB The effect of changes in laminae thickness on the fracture toughness of layered discontinuously reinforced aluminum (DRA) materials tested in the crack divider orientation was studied. Toughness was measured on monolithic DRA materials and layered DRA materials consisting of two layers of DRA material and one layer of monolithic aluminum. The fracture toughness of the individual DRA laminae was not significantly affected by changes in thickness over the thickness regime presently used in the layered DRA materials, consisting of alternating layers of DRA and a monolithic aluminum alloy. The initiation toughness of the layered DRA materials was found to be independent of both the DRA layer thickness and the aluminum ligament thickness, but greater than that of a monolithic DRA material. The crack growth resistance of the layered DRA materials was evaluated and was found to increase proportionally with the aluminum ligament thickness. The toughness improvements possible in layered DRA materials are summarized while the effects of changes in laminae thickness on the subsequent toughness are discussed via a consideration of the effects of constrained plasticity on the flow and fracture of the constituents. (C) 1997 Elsevier Science S.A. C1 CASE WESTERN RESERVE UNIV,CASE SCH ENGN,DEPT MAT SCI & ENGN,CLEVELAND,OH 44106. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551. NR 54 TC 20 Z9 20 U1 0 U2 2 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD JUN 30 PY 1997 VL 229 IS 1-2 BP 1 EP 9 DI 10.1016/S0921-5093(97)00001-4 PG 9 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA XM411 UT WOS:A1997XM41100001 ER PT J AU Kameda, J Bloomer, TE Sugita, Y Ito, A Sakurai, S AF Kameda, J Bloomer, TE Sugita, Y Ito, A Sakurai, S TI High temperature environmental attack and mechanical degradation of coatings in gas turbine blades SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE mechanical degradation; small punch testing method; sulfidation; oxidation ID SMALL-PUNCH; SUPERALLOY; SUBSTRATE AB This paper examines how in-service and thermal environmental attack influence the mechanical properties (22-950 degrees C) of CoNiCrAlY coatings over Rene 80 substrates in gas turbine blades using a small punch (SP) testing technique in conjunction with scanning Auger microprobe analysis. SP tests have clearly demonstrated strong dependence of mechanical degradation of near surface coatings on the elevated temperature environmental condition. The room temperature (RT) ductility in blade coatings decreased with increasing operating time under combined fuels of kerosene and liquefied natural gas (LNG) despite softening in used coatings. All the coatings depicted lower ductility at 825 degrees C in air than at RT but not in vacuum so that the oxidizing environment would produce deleterious effects. In-service operation under the combined fuels led to a two-fold increase in the ductile-brittle transition temperature (DBTT) over coatings observed under mainly LNG because of more extensive oxidation and grain boundary sulfidation. However, the DBTT of coatings did not change during thermal ageing at 870 degrees C in air that produced only oxidation. These findings imply that the grain boundary sulfidation would exert a stronger embrittling effect on the CoNiCrAlY coatings than the oxidation. (C) 1997 Elsevier Science S.A. C1 IOWA STATE UNIV, CTR ADV TECHNOL DEV, AMES, IA 50011 USA. CHUBU ELECT POWER CO INC, ELECT POWER R&D CTR, NAGOYA, AICHI 458, JAPAN. HITACHI LTD, MECH ENGN RES LAB, HITACHI, IBARAKI 317, JAPAN. RP Kameda, J (reprint author), IOWA STATE UNIV, AMES LAB, AMES, IA 50011 USA. NR 22 TC 22 Z9 23 U1 0 U2 8 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD JUN 30 PY 1997 VL 229 IS 1-2 BP 42 EP 54 DI 10.1016/S0921-5093(97)00003-8 PG 13 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA XM411 UT WOS:A1997XM41100004 ER PT J AU Eberhardt, AW Pandey, R Williams, JM Weimer, JJ Ila, D Zimmerman, RL AF Eberhardt, AW Pandey, R Williams, JM Weimer, JJ Ila, D Zimmerman, RL TI The roles of residual stress and surface topography on hardness of Ti implanted Ti-6Al-4V SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE ion implantation; Ti-6Al-4V; residual stress; nanohardness; atomic force microscopy; sputtering ID ION-IMPLANTATION; METALS; MICROSTRUCTURE; WEAR AB Titanium ions were implanted into Ti-6Al-4V to investigate the effects of implantation-induced residual stresses on hardness. Fluences ranged from 0 to 4.0 x 10(17) cm(-2), at 0.5 x 10(17) cm(-2) increments. Hardness values were obtained on unimplanted specimens, under various levels of bending stress, for estimation of ion-induced residual stresses in implanted specimens. The results showed that hardness increased with increasing ion fluence, up to 3.5 x 10(17) cm(-2), to a value that correlated with a bending stress of around 400 MPa. At the 4.0 x 10(17) cm(-2) fluence, the hardness dropped significantly. AFM images showed 'nodules' at this fluence, suggestive of buckling of the over-compressed surface layer. Surface texturing due to Ti implantation was evident at all fluences, suggestive of sputtering through the native oxide layer. (C) 1997 Elsevier Science S.A. C1 UNIV ALABAMA,DEPT BIOMED ENGN,BIRMINGHAM,AL 35294. OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. UNIV ALABAMA,DEPT CHEM,HUNTSVILLE,AL 35899. UNIV ALABAMA,DEPT CHEM & MAT ENGN,HUNTSVILLE,AL 35899. ALABAMA A&M UNIV,CTR IRRADIAT MAT,NORMAL,AL 35762. RP Eberhardt, AW (reprint author), UNIV ALABAMA,DEPT MECH & MAT ENGN,BIRMINGHAM,AL 35294, USA. NR 25 TC 16 Z9 16 U1 0 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD JUN 30 PY 1997 VL 229 IS 1-2 BP 147 EP 155 DI 10.1016/S0921-5093(97)00004-X PG 9 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA XM411 UT WOS:A1997XM41100014 ER PT J AU Blundell, SA Cheng, KT Sapirstein, J AF Blundell, SA Cheng, KT Sapirstein, J TI All-order binding corrections to muonium hyperfine splitting SO PHYSICAL REVIEW LETTERS LA English DT Article ID LAMB-SHIFT; ATOMS AB The use of exact Dirac-Coulomb propagators allows the evaluation of binding corrections to the Schwinger correction in ground state muonium hyperfine splitting to all orders. The calculational method is described and the results are used firstly to verify recent perturbative calculations of higher-order binding corrections and secondly to evaluate the residual terms of still higher order. Implications for muonium hyperfine splitting are discussed. C1 LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. UNIV NOTRE DAME, DEPT PHYS, NOTRE DAME, IN 46556 USA. RP Blundell, SA (reprint author), CEA GRENOBLE, DEPT RECH FONDAMENTALE MAT CONDENSEE, SI2A, 17 RUE MARTYRS, F-38054 GRENOBLE 9, FRANCE. NR 22 TC 36 Z9 36 U1 0 U2 0 PU AMER 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 JUN 30 PY 1997 VL 78 IS 26 BP 4914 EP 4917 DI 10.1103/PhysRevLett.78.4914 PG 4 WC Physics, Multidisciplinary SC Physics GA XH038 UT WOS:A1997XH03800006 ER PT J AU Sandell, A Hjortstam, O Nilsson, A Bruhwiler, PA Eriksson, O Bennich, P Rudolf, P Wills, JM Johansson, B Martensson, N AF Sandell, A Hjortstam, O Nilsson, A Bruhwiler, PA Eriksson, O Bennich, P Rudolf, P Wills, JM Johansson, B Martensson, N TI Bonding of an isolated K atom to a surface: Experiment and theory SO PHYSICAL REVIEW LETTERS LA English DT Article ID SUBMONOLAYER POTASSIUM; PHASE-TRANSITIONS; GRAPHITE; ADSORPTION; METALS; STATES; AUGER; CHEMISORPTION; ADSORBATES; MOLECULES AB We present a new and general technique with which the local properties of the unoccupied states of an adsorbed alkali atom in the low coverage limit can be studied. The method, based on a combination of experimental core level spectroscopy data and calculations, is demonstrated for the K/graphite system. We show that con excitation and decay spectra of adsorbed Ar combined with the calculations form a most powerful tool in order to determine the unoccupied density of states for an isolated K adatom. We iind that the 4s level of an isolated K atom on graphite is placed 2.7 eV above E-F, With a hybridization width of the order of only 0.1 eV. C1 FAC UNIV NOTRE DAME PAIX,LISE,B-5000 NAMUR,BELGIUM. LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87544. RP Sandell, A (reprint author), UNIV UPPSALA,DEPT PHYS,BOX 530,S-75121 UPPSALA,SWEDEN. RI Nilsson, Anders/E-1943-2011; Eriksson, Olle/E-3265-2014; Rudolf, Petra/E-6434-2014 OI Nilsson, Anders/0000-0003-1968-8696; Eriksson, Olle/0000-0001-5111-1374; Rudolf, Petra/0000-0002-4418-1769 NR 28 TC 52 Z9 52 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 JUN 30 PY 1997 VL 78 IS 26 BP 4994 EP 4997 DI 10.1103/PhysRevLett.78.4994 PG 4 WC Physics, Multidisciplinary SC Physics GA XH038 UT WOS:A1997XH03800026 ER PT J AU Tennant, DA Nagler, SE Garrett, AW Barnes, T Torardi, CC AF Tennant, DA Nagler, SE Garrett, AW Barnes, T Torardi, CC TI Excitation Spectrum and Superexchange Pathways in the Spin Dimer VODPO4 center dot 1/2D(2)O SO PHYSICAL REVIEW LETTERS LA English DT Article ID INELASTIC-NEUTRON-SCATTERING; CRYSTAL-STRUCTURE; (VO)2P2O7; LADDER; ANTIFERROMAGNET; VO(HPO4).0.5H2O; SUSCEPTIBILITY AB Magnetic excitations have been investigated in the spin dimer material VODPO4 . 1/2D(2)O using inelastic neutron scattering. A dispersionless magnetic mode was observed at an energy of 7:81(4) meV. The wave vector dependence of the scattering intensity from this mode is consistent with the excitation of isolated V4+ spin dimers with a V-V separation of 4.43(7) Angstrom. This result is unexpected since the V-V pair previously thought to constitute the magnetic dimer has a separation of 3.09 Angstrom. We identify an alternative V-V pair as the likely magnetic dimer, which involves superexchange pathways through a covalently bonded PO4 group. This surprising result casts doubt on the interpretation of (VO)(2)P2O7 as a spin ladder. C1 UNIV FLORIDA, DEPT PHYS, GAINESVILLE, FL 32611 USA. OAK RIDGE NATL LAB, THEORET & COMPUTAT PHYS SECT, OAK RIDGE, TN 37831 USA. UNIV TENNESSEE, DEPT PHYS & ASTRON, KNOXVILLE, TN 37996 USA. DUPONT CO INC, CENT RES & DEV, WILMINGTON, DE 19880 USA. RP Tennant, DA (reprint author), OAK RIDGE NATL LAB, DIV SOLID STATE, OAK RIDGE, TN 37831 USA. RI Nagler, Stephen/B-9403-2010; Nagler, Stephen/E-4908-2010; Tennant, David/Q-2497-2015 OI Nagler, Stephen/0000-0002-7234-2339; Tennant, David/0000-0002-9575-3368 NR 19 TC 52 Z9 52 U1 2 U2 5 PU AMER 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 JUN 30 PY 1997 VL 78 IS 26 BP 4998 EP 5001 DI 10.1103/PhysRevLett.78.4998 PG 4 WC Physics, Multidisciplinary SC Physics GA XH038 UT WOS:A1997XH03800027 ER PT J AU Cole, DH Shull, KR Rehn, LE Baldo, P AF Cole, DH Shull, KR Rehn, LE Baldo, P TI Metal-polymer interactions in a polymer/metal nanocomposite SO PHYSICAL REVIEW LETTERS LA English DT Article ID GOLD; DIFFUSION; DIBLOCK; FILMS AB A poly(t-butyl acrylate)/gold nanocomposite sandwich was annealed to induce diffusion of the gold particles, which was monitored using Rutherford backscattering spectrometry. Marker motion experiments were also performed to probe particle and polymer mobilities independently. The experiments revealed that particle mobility was decreased by 2 to 3 orders of magnitude compared with the predictions by Stokes-Einstein theory, Diffusion of polymer molecules through a gold particle layer is decreased by a much smaller extent. These results are attributed to bridging between particles arising, from slow exchange kinetics of polymer se,aments at the polymer/metal interface. C1 NORTHWESTERN UNIV,DEPT MAT SCI & ENGN,EVANSTON,IL 60208. RP Cole, DH (reprint author), ARGONNE NATL LAB,DIV MAT SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Shull, Kenneth/B-7536-2009 NR 16 TC 55 Z9 55 U1 0 U2 8 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 JUN 30 PY 1997 VL 78 IS 26 BP 5006 EP 5009 DI 10.1103/PhysRevLett.78.5006 PG 4 WC Physics, Multidisciplinary SC Physics GA XH038 UT WOS:A1997XH03800029 ER PT J AU Nellis, WJ Weir, ST AF Nellis, WJ Weir, ST TI Metallization of fluid molecular hydrogen at 140 GPa (1.4 Mbar) - Reply SO PHYSICAL REVIEW LETTERS LA English DT Article RP Nellis, WJ (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. RI Weir, Samuel/H-5046-2012 NR 2 TC 1 Z9 1 U1 1 U2 4 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 JUN 30 PY 1997 VL 78 IS 26 BP 5027 EP 5027 DI 10.1103/PhysRevLett.78.5027 PG 1 WC Physics, Multidisciplinary SC Physics GA XH038 UT WOS:A1997XH03800035 ER PT J AU Streli, C Wobrauschek, P Bauer, V Kregsamer, P Gorgl, R Pianetta, P Ryon, R Pahlke, S Fabry, L AF Streli, C Wobrauschek, P Bauer, V Kregsamer, P Gorgl, R Pianetta, P Ryon, R Pahlke, S Fabry, L TI Total reflection X-ray fluorescence analysis of light elements with synchrotron radiation and special X-ray tubes SO SPECTROCHIMICA ACTA PART B-ATOMIC SPECTROSCOPY LA English DT Article; Proceedings Paper CT 6th Conference on Total Reflection X-Ray Fluorescence Analysis and Related Methods (TXRF 96) CY JUN 10-14, 1996 CL EINDHOVEN, NETHERLANDS SP Philips Res Lab, Eindhoven, Inst Spektrochem Angewandte Spektroscop (ISAS), Royal Dutch Chem Soc (KNCV), Gesell Deutsch Chem (GDCh) DE total reflection X-ray fluorescence analysis; energy dispersive X-ray fluorescence analysis; synchrotron radiation; light elements ID SPECTROMETER; EXCITATION AB Total reflection X-ray fluorescence analysis (TXRF) of light elements, such as C, O and Al (atomic numbers 5-13) generally has poor sensitivity and detection limits due to poor excitation and low fluorescent yields. Special excitation sources are necessary to compensate for these physical limitations. Synchrotron radiation is the ideal source for TXRF due to its high intensity and wide spectral range extending into the low energy region required for light elements. For more routine use, special X-ray tubes can be constructed. Experiments have been performed at the Stanford Synchrotron Radiation Laboratory (SSRL) using beamline III-4, which is specially designed for the use of low energy photons. Light elements on Si wafers have been analyzed, leading to detection limits below 100 fg for Na, Mg and Al, which corresponds to about 10(9) atoms. A new vacuum chamber is introduced meeting the requirements of wafer handling without the risk of contamination and offering the possibility of scanning a certain area of the wafer, Boron was detected on a wafer with 10(14) atoms cm(-2) implanted in the surface layer. A special windowless X-ray tube with Mo, Al and Si as anode materials was also tested. With the optimization of anode geometry, beam path and excitation conditions, a detection limit of 5 pg (corresponds to 10(11) atoms) for Al was achieved. (C) 1997 Elsevier Science B.V. C1 STANFORD SYNCHROTRON RADIAT LAB,STANFORD,CA 94309. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. WACKER SILTRON AG,D-84479 BURGHAUSEN,GERMANY. RP Streli, C (reprint author), UNIV VIENNA,INST ATOM,SCHUTTELSTR 115,A-1020 VIENNA,AUSTRIA. RI Streli, Christina/K-6941-2015 OI Streli, Christina/0000-0002-5141-3177 NR 17 TC 31 Z9 31 U1 0 U2 3 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 JUN 30 PY 1997 VL 52 IS 7 BP 861 EP 872 DI 10.1016/S0584-8547(96)01663-1 PG 12 WC Spectroscopy SC Spectroscopy GA XH535 UT WOS:A1997XH53500010 ER PT J AU Werho, D Gregory, R Schauer, S Liu, X Carney, G Banks, J Knapp, J Doyle, B Diebold, AC AF Werho, D Gregory, R Schauer, S Liu, X Carney, G Banks, J Knapp, J Doyle, B Diebold, AC TI Calibration of reference materials for total-reflection X-ray fluorescence analysis by heavy ion backscattering spectrometry SO SPECTROCHIMICA ACTA PART B-ATOMIC SPECTROSCOPY LA English DT Article; Proceedings Paper CT 6th Conference on Total Reflection X-Ray Fluorescence Analysis and Related Methods (TXRF 96) CY JUN 10-14, 1996 CL EINDHOVEN, NETHERLANDS SP Philips Res Lab, Eindhoven, Inst Spektrochem Angewandte Spektroscop (ISAS), Royal Dutch Chem Soc (KNCV), Gesell Deutsch Chem (GDCh) DE ion backscattering spectrometry (IBS); reference material; TXRF; total-reflection x-ray fluorescence ID W-L-BETA AB Total-reflection X-ray fluorescence (TXRF) is widely used for the control of metallic contamination caused by surface preparation processes and silicon materials. At least three companies supply a variety of TXRF systems to the silicon integrated circuit (IC) community, and local calibration of these systems is required for their day to day operation. Differences in local calibration methods have become an issue in the exchange of information between IC manufacturers' different FABs (Fabrication Facility) and also between silicon suppliers and IC FABs. The question arises whether a universal set of fluorescence yield curves can be used by these different systems to scale system sensitivity from a single element calibration for calculation of elemental concentrations. This is emphasized by the variety of experimental conditions that are reported for TXRF data (e.g. different angles of incidence for the same X-ray source, different X-ray sources, etc.). It appears that an instrumental factor is required. We believe that heavy ion backscattering spectrometry (HIBS) provides a fundamental method of calibrating TXRF reference materials, and can be used in calculating this instrumental factor. In this paper we briefly describe the HIBS system at the Sandia National Laboratories HIBS User Facility and its application to the calibration of TXRF reference materials. We will compare HIBS and TXRF mapping capabilities and discuss the issues associated with the restrictions of some older TXRF sample stages. We will also discuss Motorola's cross-calibration of several TXRF systems using different elements as references. (C) 1997 Elsevier Science B.V. C1 SEMATECH,AUSTIN,TX 78741. MOTOROLA INC,MESA,AZ 85202. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. NR 16 TC 4 Z9 4 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 JUN 30 PY 1997 VL 52 IS 7 BP 881 EP 886 DI 10.1016/S0584-8547(96)01641-2 PG 6 WC Spectroscopy SC Spectroscopy GA XH535 UT WOS:A1997XH53500012 ER PT J AU Poole, TL Stevens, A AF Poole, TL Stevens, A TI Structural modifications of RNA influence the 5' exoribonucleolytic hydrolysis by XRN1 and HKE1 of Saccharomyces cerevisiae SO BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS LA English DT Article ID STRAND EXCHANGE PROTEIN-1; LACKING 5'->3' EXORIBONUCLEASE-1; MESSENGER-RNA; QUARTET STRUCTURES; RIBOSOMAL-RNA; YEAST-CELLS; GENE; DNA; PURIFICATION; EXONUCLEASE AB Two 5' exoribonucleases, XRN1 and HKE1, of Saccharomyces cerevisiae have been found to have very important cellular roles, XRN1 playing a key role in mRNA turnover and HKE1 in pre-rRNA processing. Here, an analysis of strong secondary structures in RNA that cause blocks or stalls (accumulation of RNA fragments that are shortened from the 5' end to the site of the secondary structure insertion) in the processive exoribonucleolytic hydrolysis reactions is reported. With both enzymes, oligo(G) tracts of lengths 18, 16, and 9 stall quite effectively, and the stalls are close to the start of the oligo(G) stretch. Two strong stem-loop structures cause measurable but low-level stalls with both enzymes. If the stem-loop structure is placed close to the 5' end of the RNA, substantial inhibition of overall RNA hydrolysis occurs with HKE1 and less, but measurable, inhibition with XRN1. RNA structural modification caused by protein complexing has been investigated by using poly(A) binding protein. The hydrolysis of poly(A) by XRN1 is inhibited by poly(A) binding protein, while HKE1 activity is not affected. (C) 1997 Academic Press. C1 OAK RIDGE NATL LAB,DIV LIFE SCI,OAK RIDGE,TN 37831. FU NCI NIH HHS [CA09336] NR 31 TC 26 Z9 28 U1 1 U2 2 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0006-291X J9 BIOCHEM BIOPH RES CO JI Biochem. Biophys. Res. Commun. PD JUN 27 PY 1997 VL 235 IS 3 BP 799 EP 805 DI 10.1006/bbrc.1997.6877 PG 7 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA XJ205 UT WOS:A1997XJ20500070 PM 9207242 ER PT J AU TonThat, DM Ziegeweid, M Song, YQ Munson, EJ Appelt, S Pines, A Clarke, J AF TonThat, DM Ziegeweid, M Song, YQ Munson, EJ Appelt, S Pines, A Clarke, J TI SQUID detected NMR of laser-polarized xenon at 4.2 K and at frequencies down to 200 Hz SO CHEMICAL PHYSICS LETTERS LA English DT Article ID ZERO-FIELD NMR; NUCLEAR-QUADRUPOLE RESONANCE; MAGNETIC-RESONANCE; CROSS-POLARIZATION; NQR; XE-129; GAS; SPECTROMETER; RELAXATION AB A spectrometer based on a dc SQUID (superconducting quantum interference device) was used to record nuclear magnetic resonance signals from laser-polarized Xe-129 at 4.2 K and at frequencies ranging from about 200 Hz to 110 kHz in magnetic fields varying from about 0.02 to 9 mT. The Xe-129 resonance linewidths were found to increase with increasing magnetic field, and, at a given field, to increase with higher Xe-129 concentration. The spin-lattice relaxation times were observed to decrease from similar to 8000 s at 5 mT to similar to 2000 s at fields below 0.05 mT. Such long relaxation times make possible a variety of spin polarization transfer experiments. (C) 1997 Published by Elsevier Science B.V. C1 UNIV CALIF BERKELEY, DEPT PHYS, BERKELEY, CA 94720 USA. UNIV CALIF BERKELEY, DEPT CHEM, BERKELEY, CA 94720 USA. RP TonThat, DM (reprint author), UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, DIV MAT SCI, BERKELEY, CA 94720 USA. RI Appelt, Stephan/I-3168-2012; Appelt, Stefan/C-1541-2017 OI Appelt, Stefan/0000-0001-6036-2167 NR 32 TC 20 Z9 21 U1 1 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 JUN 27 PY 1997 VL 272 IS 3-4 BP 245 EP 249 DI 10.1016/S0009-2614(97)88016-5 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA XH440 UT WOS:A1997XH44000017 ER PT J AU Krissinel, EB Jellinek, J AF Krissinel, EB Jellinek, J TI 13-atom Ni-Al alloy clusters: Correlation between structural and dynamical properties SO CHEMICAL PHYSICS LETTERS LA English DT Article ID DENSITY-FUNCTIONAL THEORY; BIMETALLIC CLUSTERS; IONIZATION-POTENTIALS; ELECTRONIC-STRUCTURE; TRANSITION-METALS; REACTIVITY; ALUMINUM; COBALT; SPECTROSCOPY; EXCITATIONS AB Further analysis of structural and dynamical properties of mixed Ni-Al 13-atom clusters is presented. A model explaining the dependence of the principal structural and energy characteristics of the clusters on their composition is described. Homotop-specific features of the dynamics are derived and analyzed. Published by Elsevier Science B.V. C1 RUSSIAN ACAD SCI,INST WATER & ENVIRONM PROBLEMS,SIBERIAN BRANCH,BARNAUL 656099,RUSSIA. RP Krissinel, EB (reprint author), ARGONNE NATL LAB,DIV CHEM,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 27 TC 41 Z9 41 U1 0 U2 1 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 JUN 27 PY 1997 VL 272 IS 3-4 BP 301 EP 312 DI 10.1016/S0009-2614(97)88024-4 PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA XH440 UT WOS:A1997XH44000025 ER PT J AU GuanSajonz, H Guiochon, G Davis, E Gulakowski, K Smith, DW AF GuanSajonz, H Guiochon, G Davis, E Gulakowski, K Smith, DW TI Study of the physico-chemical properties of some packing materials .3. Pore size and surface area distribution SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article DE stationary phases, LC; pore size distribution; surface area distribution ID EXCLUSION CHROMATOGRAPHY AB The pore structures of four conventional stationary phases for reversed-phase liquid chromatography have been studied and compared. Helium pycnometry was used to determine the total porosity of the packing. Nitrogen sorptometry, inverse size-exclusion chromatography and mercury intrusion porosimetry have been applied to Kromasil, Vydac, YMC and Zorbax 10 mu m particles of C-18 chemically bonded silica. The agreement between the results derived from the three methods used for the determination of the volume pore size and the surface area distributions is excellent. C1 UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831. MICROMERIT,NORCROSS,GA 30093. NR 22 TC 24 Z9 25 U1 1 U2 7 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 JUN 27 PY 1997 VL 773 IS 1-2 BP 33 EP 51 DI 10.1016/S0021-9673(97)00201-X PG 19 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA XJ881 UT WOS:A1997XJ88100004 ER PT J AU Joachimiak, A QuaiteRandall, E Tollaksen, S Mai, XH Adams, MWW Josephs, R Giometti, C AF Joachimiak, A QuaiteRandall, E Tollaksen, S Mai, XH Adams, MWW Josephs, R Giometti, C TI Purification of chaperonins from thermophilic bacteria and archaea SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article DE chaperonins; proteins ID ESCHERICHIA-COLI; HYPERTHERMOPHILIC ARCHAEON; SULFOLOBUS-SHIBATAE; HEAT-SHOCK; PYROCOCCUS-FURIOSUS; GROEL; GENE; SOLFATARICUS; EXPRESSION; PROTEINS AB Chaperonins are among the most abundant proteins in thermophilic and hyperthermophilic microorganisms. A fast and efficient protocol has been designed to purify chaperonins from natural microbial sources on a milligram scale. The procedure takes advantage of the low isoelectric point and high molecular mass of chaperonins. A strong anion-exchange matrix in combination with gel permeation chromatography and separation on a high-resolution MonoQ column were used to purify four chaperonins from bacteria and archaea. We also show how the procedure for one of the hyperthermophilic chaperones can be easily scaled up. Pure chaperonins were characterized by two-dimensional polyacrylamide gel electrophoresis and high-performance liquid chromatography to establish heterogeneity. Pure chaperonins retain the characteristic double ring structure in electron microscopy and they bind unfolded proteins. C1 UNIV GEORGIA,ATHENS,GA 30602. UNIV CHICAGO,CHICAGO,IL 60637. RP Joachimiak, A (reprint author), ARGONNE NATL LAB,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 30 TC 6 Z9 6 U1 0 U2 0 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 JUN 27 PY 1997 VL 773 IS 1-2 BP 131 EP 138 DI 10.1016/S0021-9673(97)00230-6 PG 8 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA XJ881 UT WOS:A1997XJ88100013 ER PT J AU Mayer, DL Fritz, JS AF Mayer, DL Fritz, JS TI Semi-micro solid-phase extraction of organic compounds from aqueous and biological samples SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article DE solid-phase micro extraction ID WATER; MICROEXTRACTION AB A technique is described for performing solid-phase extractions on a semi-micro scale. Thin membrane disks 4 mm in diameter containing lightly sulfonated polystyrene or Silicalite particles are placed in the hub of a syringe needle. Aqueous samples (1-6 mi) are passed through the membrane disks and the extracted compounds are subsequently eluted with 20-50 mu l of an organic solvent. Unlike solid-phase micro extraction (SPME) which uses a coated fiber, the present method is essentially a total extraction technique. Recoveries >90% were generally obtained for a wide variety of test compounds. The same test compounds in human urine, albumin and human serum samples can be extracted without any pretreatment other than addition of a suitable surfactant. A ''double-pass'' technique was developed for convenient field sampling. C1 IOWA STATE UNIV,DEPT CHEM,AMES,IA 50011. US DOE,AMES LAB,AMES,IA 50011. NR 19 TC 10 Z9 10 U1 0 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 JUN 27 PY 1997 VL 773 IS 1-2 BP 189 EP 197 DI 10.1016/S0021-9673(97)00244-6 PG 9 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA XJ881 UT WOS:A1997XJ88100020 PM 9228797 ER PT J AU Katul, G Hsieh, CI Kuhn, G Ellsworth, D Nie, DL AF Katul, G Hsieh, CI Kuhn, G Ellsworth, D Nie, DL TI Turbulent eddy motion at the forest-atmosphere interface SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SENSIBLE HEAT-FLUX; DECIDUOUS FOREST; BOUNDARY-LAYER; REYNOLDS STRESS; SURFACE-LAYER; PINE FOREST; SMOOTH-WALL; CANOPY; SCALAR; STATISTICS AB Ejection and sweep eddy motions in the atmospheric surface layer (ASL) are widely accepted as being responsible for much of land surface evaporation, sensible heat flux, and momentum flux; however, less is known about this type of eddy motion within the canopy sublayer (CSL) of forested systems. The present study analyzed the ejection-sweep properties at the canopy-atmosphere interface of a 13 m tall, uniformly aged southern loblolly pine stand and a 33 m tall, unevenly aged hardwood stand using velocity and scalar (temperature, water vapor, and carbon dioxide) fluctuation measurements at the canopy-atmosphere interface. It was found that the measured sweeps and ejections time fractions for scalars and momentum are comparable and are in good agreement with other laboratory and field experiments. This investigation demonstrates that the third-order cumulant expansion method (GEM) reproduces the measured relative flux contribution of ejections and sweeps (Delta S-0) and the difference between sweep and ejection time fractions for both momentum and scalars at the canopy-atmosphere interface in contrast to findings from a previous ASL experiment. A linkage between Delta S-0 and the scalar flux budget is derived and tested via the third-order CEM at the canopy-atmosphere interface for the pine and the hardwood stands. It is shown that Delta S-0 can be related to the dimensionless scalar flux transport term whose gradient is central to the scalar variance budget. Also, the derived relationship is independent of canopy roughness or scalar sources and sinks. Hence this investigation establishes an analytical linkage between second-order closure models, the ejection-sweep cycle,and third-order CEM at the canopy-atmosphere interface. Dissimilarity between the ejection-sweep cycle for scalar and momentum transport is considered via conditional probability distributions at both forest stands. In contrast to a laboratory heat dispersion experiment, it is shown that while the ejection-sweep cycles for scalar and momentum transport are intimately linked, they are not identical. Therefore the results from momentum ejection-sweeps investigations cannot be extrapolated to scalar transport. Comparisons with other laboratory experiments are also discussed, especially in relation to the scalar ejection and sweep time fractions. C1 MANTECH ENVIRONM TECHNOL INC, RES TRIANGLE PK, NC 27709 USA. BROOKHAVEN NATL LAB, DEPT APPL SCI, BIOSYST & PROC SCI DIV, UPTON, NY 11973 USA. RP DUKE UNIV, SCH ENVIRONM, CTR HYDROL SCI, BOX 90328, DURHAM, NC 27708 USA. RI Katul, Gabriel/A-7210-2008; OI Katul, Gabriel/0000-0001-9768-3693; Ellsworth, David/0000-0002-9699-2272 NR 78 TC 68 Z9 70 U1 1 U2 8 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 JUN 27 PY 1997 VL 102 IS D12 BP 13409 EP 13421 DI 10.1029/97JD00777 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA XH196 UT WOS:A1997XH19600001 ER PT J AU Allen, DR Reck, RA AF Allen, DR Reck, RA TI Daily variations in TOMS total ozone data SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID WAVES; STRATOSPHERE; TRANSPORT; BREAKING; TRENDS AB The spatial and seasonal distributions of daily fluctuations in total ozone from 60 degrees N to 60 degrees S are analyzed by using 14.5 years of total ozone mapping spectrometer (TOMS) data on a 5 degrees latitude by 15 degrees longitude grid. Root mean square day to day differences maximize near 30 Dobson units (DU) in the midlatitudes of both hemispheres from late fall to early spring. The contributions of these fluctuations due to planetary- and medium-scale waves are analyzed using sinusoidal zonal wave filtering. Daily midlatitude variations from planetary-scale waves are smaller than those from medium-scale waves and mainly occur from late fall to early spring, while strong medium-scale variations persist throughout fall, winter, and spring. An exception is the southern hemisphere high latitudes, where contortions and breakup of the polar vortex cause large daily variations on planetary scales during September and October. Tropical total ozone fluctuations due to planetary-scale waves are slightly larger than those due to medium-scale waves in all seasons. A climatological table of monthly RMS day to day total ozone changes is provided as a reference. RP Allen, DR (reprint author), ARGONNE NATL LAB, GLOBAL CLIMATE CHANGE PROGRAM, 9700 S CASS AVE, ER-203, ARGONNE, IL 60439 USA. NR 27 TC 17 Z9 18 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 JUN 27 PY 1997 VL 102 IS D12 BP 13603 EP 13608 DI 10.1029/97JD00632 PG 6 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA XH196 UT WOS:A1997XH19600019 ER PT J AU Grossman, AS Grant, KE Blass, WE Wuebbles, DJ AF Grossman, AS Grant, KE Blass, WE Wuebbles, DJ TI Radiative forcing calculations for CH3Cl and CH3Br SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID METHYL-CHLORIDE; BAND; ATMOSPHERES AB Methyl chloride, CH3Cl, and methyl bromide, CH3Br, are particularly important in the global atmosphere as major natural sources of chlorine and bromine to the stratosphere. The production of these gases is dominated by natural sources, but smaller, important anthropogenic sources, such as agricultural fumigation and/or biomass burning, also exist. As absorbers of infrared radiation these gases are of interest for their potential effect on the tropospheric energy balance as well as for chemical interactions. In this study we estimate the radiative forcing and Global Warming Potentials (GWPs) of CH3Cl and CH3Br. Our calculations use an infrared radiative transfer model based on the correlated k-distribution algorithm for band absorption. Radiative forcing values of 0.0047 W/m(2) per part per billion by volume (ppbv) for CH3Cl in the troposphere and 0.0049 W/m(2) per ppbv for CH3Br in the troposphere were obtained. On a per molecule basis the radiative forcing values are about 2% of the forcing of CFC II and about 270 times the forcing of CO2. GWPs for these gases are about 8 for CH3Cl and about 4 for CH3Br (100 year time integration, CO2 = 1). These results indicate that while CH3Cl and CH3Br have direct GWPs similar to that of CH4, the current emission rates are too low to contribute meaningfully to atmospheric greenhouse heating effects. C1 UNIV ILLINOIS, DEPT ATMOSPHER SCI, URBANA, IL 61801 USA. UNIV TENNESSEE, DEPT PHYS & ASTRON, KNOXVILLE, TN 37996 USA. RP Grossman, AS (reprint author), LAWRENCE LIVERMORE NATL LAB, DIV ATMOSPHER SCI, 7000 EAST AVE, L-103, LIVERMORE, CA 94550 USA. RI Blass, William/A-2792-2008 NR 38 TC 3 Z9 3 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 JUN 27 PY 1997 VL 102 IS D12 BP 13651 EP 13656 DI 10.1029/97JD00611 PG 6 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA XH196 UT WOS:A1997XH19600023 ER PT J AU Brand, HV Redondo, A Hay, PJ AF Brand, HV Redondo, A Hay, PJ TI Theoretical studies of CO adsorption on H-ZSM-5 and hydrothermally treated H-ZSM-5 SO JOURNAL OF MOLECULAR CATALYSIS A-CHEMICAL LA English DT Article DE zeolite; bronsted acidity; CO adsorption; dealumination; IR spectra; DFT; theory; hydroxyl frequencies; scaling factors ID SCALING FACTORS; FORCE-FIELDS; ZEOLITES; ACID; SITES; ABINITIO; HYDROXYL; ENERGIES; EXCHANGE; SILANOL AB The adsorption of CO on H-ZSM-5 and hydrothermally treated H-ZSM-5 is studied by means of quantum mechanical calculations. Good agreement with experimental FTIR data is established. The Al(OH)(3) dimer is found to account for the new bands that appear in the hydroxyl region of the FTIR spectra of H-ZSM-5 as a result of hydrothermal treatment. Effects of electron correlation (investigated through second-order Moller-Plesset perturbation and density-functional theory) are compared with Hartree-Fock results. Red shifts in the stretching frequency of bridging OH groups due to the CO interaction are best described by the density-functional approach. Frequency shifts are found to correlate with changes in local geometry. C1 LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. NR 28 TC 23 Z9 23 U1 0 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1381-1169 J9 J MOL CATAL A-CHEM JI J. Mol. Catal. A-Chem. PD JUN 27 PY 1997 VL 121 IS 1 BP 45 EP 62 DI 10.1016/S1381-1169(96)00456-6 PG 18 WC Chemistry, Physical SC Chemistry GA XG413 UT WOS:A1997XG41300006 ER PT J AU Lu, YL Wei, T Duewer, F Lu, YQ Ming, NB Schultz, PG Xiang, XD AF Lu, YL Wei, T Duewer, F Lu, YQ Ming, NB Schultz, PG Xiang, XD TI Nondestructive imaging of dielectric-constant profiles and ferroelectric domains with a scanning-tip microwave near-field microscope SO SCIENCE LA English DT Article ID 2ND-HARMONIC GENERATION; GROWTH STRIATIONS; BLUE-LIGHT; LINBO3; CRYSTALS; WALLS AB Variations in dielectric constant and patterns of microwave loss have been imaged in a yttrium-doped LiNbO3 crystal with periodic ferroelectric domains with the use of a scanning-tip near-field microwave microscope. Periodic profiles of dielectric constant and images of ferroelectric domain boundaries were observed at submicrometer resolution, The combination of these images showed a growth-instability-induced defect of periodic domain structure. Evidence of a lattice-edge dislocation has also been observed through a stress-induced variation in dielectric constant. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,INST MOL DESIGN,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,HOWARD HUGHES MED INST,BERKELEY,CA 94720. NANJING UNIV,NATL LAB SOLID STATE MICROSTRUCT,NANJING 210093,PEOPLES R CHINA. RI Xiang, Xiaodong/A-9445-2012; Lu, Yan-qing/A-5314-2009; Xiang, Xiaodong/A-5936-2017 OI Lu, Yan-qing/0000-0001-6151-8557; NR 18 TC 91 Z9 93 U1 5 U2 42 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD JUN 27 PY 1997 VL 276 IS 5321 BP 2004 EP 2006 DI 10.1126/science.276.5321.2004 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA XG748 UT WOS:A1997XG74800052 ER PT J AU Guarnera, A Chomaz, P Colonna, M Randrup, J AF Guarnera, A Chomaz, P Colonna, M Randrup, J TI Multifragmentation with Brownian one-body dynamics SO PHYSICS LETTERS B LA English DT Article DE multifragmentation; Boltzmann-Langevin theory; Brownian motion; kinetic equation; fluctuations; instabilities ID NUCLEAR COLLISIONS; FLUCTUATIONS; INSTABILITY AB A first application is made of Brownian One-Body Dynamics to nuclear multifragmentation. A gold nucleus is compressed to double density and then let free to evolve under the combined influence of the effective one-body field and the residual two-body collision processes, with the effects of the fluctuations included whenever local spinodal instability occurs. The system quickly expands into a hollow and unstable configuration which transforms into several intermediate-mass fragments. The analysis of the resulting fragment pattern suggests that the model provides a physically reasonable description of nuclear multifragmentation processes. (C) 1997 Published by Elsevier Science B.V. C1 LAB NAZL SUD, I-95129 CATANIA, ITALY. CTR ETUD SACLAY, CEA, DAPNIA, F-91191 GIF SUR YVETTE, FRANCE. UNIV CALIF BERKELEY, LAWRENCE BERKELEY NATL LAB, DIV NUCL SCI, BERKELEY, CA 94720 USA. RP GANIL, BP 5027, F-14021 CAEN, FRANCE. NR 15 TC 30 Z9 30 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 EI 1873-2445 J9 PHYS LETT B JI Phys. Lett. B PD JUN 26 PY 1997 VL 403 IS 3-4 BP 191 EP 196 DI 10.1016/S0370-2693(97)00515-7 PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA XJ270 UT WOS:A1997XJ27000001 ER PT J AU Chang, SH Coriano, C Field, RD Gordon, LE AF Chang, SH Coriano, C Field, RD Gordon, LE TI Spin dependent Drell-Yan beyond leading order: Non-singlet corrections to O(alpha(2)(s)) SO PHYSICS LETTERS B LA English DT Article ID CROSS-SECTION; QCD AB We present parton-level analytical results for the next-to-leading order non-singlet virtual and real corrections to the Drell-Yan differential cross-section. The dependence of the differential cross section on the helicity of the initial state partons is shown explicitly (the spins of the final state partons are summed). The calculation is implemented in dimensional regularization within the <(MS)over bar> scheme and with the 't Hooft-Veltman prescriptions for the n-dimensional gamma(5). Both the polarized initial state and the unpolarized cross sections can be obtained from our result. Our unpolarized cross section agrees with the previous result of Ellis, Martinelli and Petronzio in the non-singlet sector. (C) 1997 Published by Elsevier Science B.V. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. RP Chang, SH (reprint author), UNIV FLORIDA,DEPT PHYS,INST FUNDAMENTAL THEORY,GAINESVILLE,FL 32611, USA. NR 16 TC 8 Z9 8 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD JUN 26 PY 1997 VL 403 IS 3-4 BP 344 EP 352 DI 10.1016/S0370-2693(97)00542-X PG 9 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA XJ270 UT WOS:A1997XJ27000025 ER PT J AU Aitala, EM Amato, S Anjos, JC Appel, JA Ashery, D Banerjee, S Bediaga, I Blaylock, G Bracker, SB Burchat, PR Burnstein, RA Carter, T Carvalho, HS Copty, NK Cremaldi, LM Darling, C Denisenko, K Fernandez, A Gagnon, P Gobel, C Gounder, K Halling, AM Herrera, G Hurvits, G James, C Kasper, PA Kwan, S Langs, DC Leslie, J Lundberg, B MayTalBeck, S Meadows, B Neto, JRTD Milburn, RH deMiranda, JM Napier, A Nguyen, A dOliveira, AB OShaughnessy, K Peng, KC Perera, LP Purohit, MV Quinn, B Radeztsky, S Rafatian, A Reay, NW Reidy, JJ dosReis, AC Rubin, HA Santha, AKS Santoro, AS Schwartz, AJ Sheaff, M Sidwell, RA Slaughter, AJ Sokoloff, MD Stanton, NR Stenson, K Summers, DJ Takach, S Thorne, K Tripathi, AK Watanabe, S WeissBabai, R Wiener, J Witchey, N Wolin, E Yi, D Yoshida, S Zaliznyak, R Zhang, C AF Aitala, EM Amato, S Anjos, JC Appel, JA Ashery, D Banerjee, S Bediaga, I Blaylock, G Bracker, SB Burchat, PR Burnstein, RA Carter, T Carvalho, HS Copty, NK Cremaldi, LM Darling, C Denisenko, K Fernandez, A Gagnon, P Gobel, C Gounder, K Halling, AM Herrera, G Hurvits, G James, C Kasper, PA Kwan, S Langs, DC Leslie, J Lundberg, B MayTalBeck, S Meadows, B Neto, JRTD Milburn, RH deMiranda, JM Napier, A Nguyen, A dOliveira, AB OShaughnessy, K Peng, KC Perera, LP Purohit, MV Quinn, B Radeztsky, S Rafatian, A Reay, NW Reidy, JJ dosReis, AC Rubin, HA Santha, AKS Santoro, AS Schwartz, AJ Sheaff, M Sidwell, RA Slaughter, AJ Sokoloff, MD Stanton, NR Stenson, K Summers, DJ Takach, S Thorne, K Tripathi, AK Watanabe, S WeissBabai, R Wiener, J Witchey, N Wolin, E Yi, D Yoshida, S Zaliznyak, R Zhang, C TI Search for CP violation in charged D meson decays SO PHYSICS LETTERS B LA English DT Article AB We report results of a search for CP violation in the singly Cabibbo-suppressed decays D+ --> K(-)K(+)pi(+), phi pi(+), (K) over bar(892)K-0(+), and pi(-)pi(+)pi(+) based on data from the charm hadroproduction experiment E791 at Fermilab. We search for a difference in the D+ and D- decay rates for each of the final states. No evidence for a difference is seen. The decay rate asymmetry parameters (ACP), defined as the difference in the D+ and D- decay rates divided by the sum of the decay rates, are measured to be: A(CP)(KK pi) = -0.014+/-0.029, A(CP) (phi pi) = -0.028+/-0.036, A(CP) (K*(892)K) = -0.010+/-0.050, and A(CP)(7 pi pi pi) = -0.017+/-0.042. (C) 1997 Published by Elsevier Science B.V. C1 CTR BRASILEIRO PESQUISAS FIS,RIO JANEIRO,BRAZIL. UNIV CALIF SANTA CRUZ,SANTA CRUZ,CA 95064. UNIV CINCINNATI,CINCINNATI,OH 45221. CINVESTAV IPN,MEXICO CITY 14000,DF,MEXICO. FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. IIT,CHICAGO,IL 60616. KANSAS STATE UNIV,MANHATTAN,KS 66506. UNIV MASSACHUSETTS,AMHERST,MA 01003. OHIO STATE UNIV,COLUMBUS,OH 43210. PRINCETON UNIV,PRINCETON,NJ 08544. UNIV AUTONOMA PUEBLA,MEXICO CITY,DF,MEXICO. UNIV S CAROLINA,COLUMBIA,SC 29208. STANFORD UNIV,STANFORD,CA 94305. TEL AVIV UNIV,IL-69978 TEL AVIV,ISRAEL. TUFTS UNIV,MEDFORD,MA 02155. UNIV WISCONSIN,MADISON,WI 53706. YALE UNIV,NEW HAVEN,CT 06511. RP Aitala, EM (reprint author), UNIV MISSISSIPPI,UNIVERSITY,MS 38677, USA. RI Gobel Burlamaqui de Mello, Carla /H-4721-2016; de Mello Neto, Joao/C-5822-2013; Anjos, Joao/C-8335-2013 OI Gobel Burlamaqui de Mello, Carla /0000-0003-0523-495X; de Mello Neto, Joao/0000-0002-3234-6634; NR 19 TC 27 Z9 27 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD JUN 26 PY 1997 VL 403 IS 3-4 BP 377 EP 382 DI 10.1016/S0370-2693(97)00565-0 PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA XJ270 UT WOS:A1997XJ27000030 ER PT J AU Aggarwal, MM Angelis, ALS Antonenko, V Awes, TC Badyal, SK Barlag, C Bhalla, KB Bhatia, VS Blume, C Bock, D Bohne, EM Bucher, D Buijs, A Chattopadhyay, S Claussen, A Clewing, G Das, AC Devanand Donni, P Durieux, E Majumdar, MRD Foka, P Fokin, S Ganti, MS Garpman, S Geurts, F Ghosh, TK Glasow, R Gupta, SK Gustafsson, HA Gutbrod, HH Hartig, M He, XC Holker, G Ippolitov, M Izycki, M Kachroo, S Kalechofsky, H Kamermans, R Kampert, KH Karadjev, K Kolb, BW Langbein, I Langheinrich, J Lebedev, A Lohner, H Loknathan, S Manko, V Martin, M Mittra, IS Mookerjee, S Naef, H Nayak, SK Nayak, TK Nikolaev, S Nystrand, J Obenshain, FE Oskarsson, A Otterlund, I Peitzmann, T Plasil, F Purschke, M Raniwala, S Rao, NK Rosselet, L Roters, B Rubio, JM Saini, S Sambyal, S Santo, R Schmidt, HR Siemiarczuk, T Siemssen, RH Sinha, BC Slegt, S Soderstrom, K Solomey, N Sorensen, SP Stefanek, G Steinhaeuser, P Stenlund, E Ster, A Stuken, D Trivedi, MD Twenhoefel, C VanEijndhoven, N VanHeeringen, WH Vinogradov, A Viyogi, YP Weber, S Young, GR AF Aggarwal, MM Angelis, ALS Antonenko, V Awes, TC Badyal, SK Barlag, C Bhalla, KB Bhatia, VS Blume, C Bock, D Bohne, EM Bucher, D Buijs, A Chattopadhyay, S Claussen, A Clewing, G Das, AC Devanand Donni, P Durieux, E Majumdar, MRD Foka, P Fokin, S Ganti, MS Garpman, S Geurts, F Ghosh, TK Glasow, R Gupta, SK Gustafsson, HA Gutbrod, HH Hartig, M He, XC Holker, G Ippolitov, M Izycki, M Kachroo, S Kalechofsky, H Kamermans, R Kampert, KH Karadjev, K Kolb, BW Langbein, I Langheinrich, J Lebedev, A Lohner, H Loknathan, S Manko, V Martin, M Mittra, IS Mookerjee, S Naef, H Nayak, SK Nayak, TK Nikolaev, S Nystrand, J Obenshain, FE Oskarsson, A Otterlund, I Peitzmann, T Plasil, F Purschke, M Raniwala, S Rao, NK Rosselet, L Roters, B Rubio, JM Saini, S Sambyal, S Santo, R Schmidt, HR Siemiarczuk, T Siemssen, RH Sinha, BC Slegt, S Soderstrom, K Solomey, N Sorensen, SP Stefanek, G Steinhaeuser, P Stenlund, E Ster, A Stuken, D Trivedi, MD Twenhoefel, C VanEijndhoven, N VanHeeringen, WH Vinogradov, A Viyogi, YP Weber, S Young, GR TI Azimuthal anisotropy in S+Au reactions at 200 A GeV SO PHYSICS LETTERS B LA English DT Article ID HEAVY-ION COLLISIONS; COLLECTIVE FLOW; NUCLEUS COLLISIONS; ENERGY AB Azimuthal correlations of photons produced at mid-rapidity in 200 A GeV S + Au collisions have been studied using a preshower photon multiplicity detector in the WA93 experiment. The Fourier expansion method has been employed to estimate the event plane via the anisotropy of the event as a function of centrality. The event plane correlation technique has been used to determine the true event anisotropy, beyond the anisotropy which arises due to finite multiplicity. The VENUS event generator with rescattering and proper simulation of the detector response can explain only a portion of the observed anisotropy. The residual anisotropy is found to be of the order of 5% for semi-central collisions. This suggests that directed collective flow of the produced particles is present at SPS energies. (C) 1997 Published by Elsevier Science B.V. C1 UNIV GENEVA,CH-1211 GENEVA 4,SWITZERLAND. IV KURCHATOV ATOM ENERGY INST,RU-123182 MOSCOW,RUSSIA. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. UNIV JAMMU,JAMMU 180001,INDIA. UNIV MUNSTER,D-48149 MUNSTER,GERMANY. UNIV RAJASTHAN,JAIPUR 302004,RAJASTHAN,INDIA. UNIV UTRECHT,NIKHEF H,NL-3508 TA UTRECHT,NETHERLANDS. BHABHA ATOM RES CTR,CTR VARIABLE ENERGY CYCLOTRON,CALCUTTA 700064,W BENGAL,INDIA. LUND UNIV,SE-22100 LUND,SWEDEN. GSI DARMSTADT,D-64220 DARMSTADT,GERMANY. UNIV TENNESSEE,KNOXVILLE,TN 37996. UNIV GRONINGEN,KVI,NL-9747 AA GRONINGEN,NETHERLANDS. INST NUCL STUDIES,PL-00681 WARSAW,POLAND. RP Aggarwal, MM (reprint author), PANJAB UNIV,CHANDIGARH 160014,UT,INDIA. RI Peitzmann, Thomas/K-2206-2012; Lohner, Herbert/B-2397-2014; OI Peitzmann, Thomas/0000-0002-7116-899X; Lohner, Herbert/0000-0002-7441-739X; Kampert, Karl-Heinz/0000-0002-2805-0195 NR 20 TC 34 Z9 34 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD JUN 26 PY 1997 VL 403 IS 3-4 BP 390 EP 396 DI 10.1016/S0370-2693(97)00566-2 PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA XJ270 UT WOS:A1997XJ27000032 ER PT J AU Sussman, M Smereka, P AF Sussman, M Smereka, P TI Axisymmetric free boundary problems SO JOURNAL OF FLUID MECHANICS LA English DT Article ID BUOYANCY-DRIVEN MOTION; TRANSIENT CAVITIES; NUMERICAL-SOLUTION; QUIESCENT LIQUID; FLUID-MECHANICS; BUBBLES; CURVATURE; COLLAPSE; SURFACE AB We present a number of three-dimensional axisymmetric free boundary problems for two immiscible fluids, such as air and water. A level set method is used where the interface is the zero level set of a continuous function while the two fluids are solutions of the incompressible Navier-Stokes equation. We examine the rise and distortion of an initially spherical bubble into cap bubbles and toroidal bubbles. Steady solutions for gas bubbles rising in a liquid are computed, with favourable comparisons to experimental data. We also study the inviscid limit and compare our results with a boundary integral method. The problems of an air bubble bursting at a free surface and a liquid drop hitting a free surface are also computed. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,CTR COMPUTAT SCI & ENGN,BERKELEY,CA 94720. UNIV MICHIGAN,DEPT MATH,ANN ARBOR,MI 48109. RI Smereka, Peter/F-9974-2013 NR 37 TC 151 Z9 156 U1 3 U2 20 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 SN 0022-1120 J9 J FLUID MECH JI J. Fluid Mech. PD JUN 25 PY 1997 VL 341 BP 269 EP 294 DI 10.1017/S0022112097005570 PG 26 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA XK666 UT WOS:A1997XK66600011 ER PT J AU Agarwal, A Haynes, TE Eaglesham, DJ Gossmann, HJ Jacobson, DC Poate, JM Erokhin, YE AF Agarwal, A Haynes, TE Eaglesham, DJ Gossmann, HJ Jacobson, DC Poate, JM Erokhin, YE TI Interstitial defects in silicon from 1-5 keV Si+ ion implantation SO APPLIED PHYSICS LETTERS LA English DT Article ID ANOMALOUS TRANSIENT DIFFUSION; ENHANCED DIFFUSION; BORON; MODEL AB Extended defects from 5-, 2-, and 1-keV Si+ ion implantation are investigated by transmission electron microscopy using implantation doses of 1 and 3 x 10(14) cm(-2) and annealing temperatures from 750 to 900 degrees C. Despite the proximity of the surface, {311}-type defects are observed even for 1 keV., Samples with a peak concentration of excess interstitials exceeding similar to 1% of the atomic density also contain some {311} defects which are corrugated across their width. These so-called zig-zag {311} defects are more stable than the ordinary {311} defects, having a dissolution rate at 750 degrees C which is ten times smaller. Due to their enhanced stability, the zig-zag {311} defects grow to lengths that are many times longer than their distance from the surface. It is proposed that zig-zag {311} defects form during the early stages of annealing by coalescence the high volume density of {311} defects confined within a very narrow implanted layer. These findings indicate that defect formation and dissolution will continue to control the interstitial supersaturation from ion implantation down to very low energies, (C) 1997 American Institute of Physics. C1 AT&T BELL LABS,LUCENT TECHNOL,MURRAY HILL,NJ 07974. EATON CORP,BEVERLY,MA 01915. RP Agarwal, A (reprint author), OAK RIDGE NATL LAB,MS-6048,OAK RIDGE,TN 37831, USA. RI Haynes, Tony/P-8932-2015 OI Haynes, Tony/0000-0003-2871-4745 NR 18 TC 54 Z9 54 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 JUN 23 PY 1997 VL 70 IS 25 BP 3332 EP 3334 DI 10.1063/1.119161 PG 3 WC Physics, Applied SC Physics GA XH231 UT WOS:A1997XH23100002 ER PT J AU Sun, XD Gao, C Wang, JS Xiang, XD AF Sun, XD Gao, C Wang, JS Xiang, XD TI Identification and optimization of advanced phosphors using combinatorial libraries SO APPLIED PHYSICS LETTERS LA English DT Article ID LUMINESCENCE AB A combination of thin-film deposition and physical masking steps were used to generate libraries of the rare earth activated refractory metal oxides, Gd(La,Sr)AlOx. Systematic variation of composition and processing conditions afforded tricolor phosphors with the following nominal compositions, (Gd0.46Sr0.31)Al1.23OxF1.38:Eu-0.06(2+) (green), La0.5Al1.5Ox:Eu-0.04(2+) (blue), and Gd0.77Al1.23Ox:Eu-0.06(2+) (red), which had quantum efficiencies of greater than or equal to 94%, similar or equal to 60%, and greater than or equal to 93%, respectively at lambda(max)(ex). The high quenching temperatures (250-350 degrees C), good chromaticities and refractory nature of these phosphors are desirable features for display applications. (C) 1997 American Institute of Physics. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,INST MOL DESIGN,BERKELEY,CA 94720. RI Xiang, Xiaodong/A-9445-2012; Xiang, Xiaodong/A-5936-2017 NR 14 TC 71 Z9 80 U1 2 U2 8 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 JUN 23 PY 1997 VL 70 IS 25 BP 3353 EP 3355 DI 10.1063/1.119168 PG 3 WC Physics, Applied SC Physics GA XH231 UT WOS:A1997XH23100009 ER PT J AU Grant, PM Haas, JS Whipple, RE Andresen, BD AF Grant, PM Haas, JS Whipple, RE Andresen, BD TI A possible chemical explanation for the events associated with the death of Gloria Ramirez at Riverside General Hospital SO FORENSIC SCIENCE INTERNATIONAL LA English DT Article DE toxic incident; chemical scenario; Riverside General Hospital; Emergency Room 'mystery fumes' ID FREE-RADICAL FORMATION; TUMOR-NECROSIS-FACTOR; METHANESULFONIC-ACID; DIMETHYL-SULFOXIDE; HYDROXYL; GLUTATHIONE; INVITRO; CELLS AB The events associated with the death of Gloria Ramirez at Riverside General Hospital on 19 February 1994 have been portrayed as a major medical mystery. A potential chemical explanation for this incident has been developed. The hypothetical scenario depends upon the oxidation of a common solvent, dimethyl sulfoxide, through dimethyl sulfone to dimethyl sulfate. The latter compound is a volatile and highly toxic agent that can be quite hazardous to humans in small amounts. It is also environmentally nonpersistent. Much of the mystery surrounding the circumstances at the hospital may be explainable if this postulated metabolic pathway took place at the time of the emergency room incident. Although dimethyl sulfate was not detected in any analyses pertinent to this event, there are plausible scientific explanations to account for that fact. The sulfate anion, a hydrolysis product of dimethyl sulfate, was measured at an appreciably elevated concentration in Ramirez' blood. The descriptions of the symptoms of the hospital-staff victims appear quite consistent with dimethyl sulfate exposures. This paper attempts to make some sense of the reported data and eyewitness accounts, and perhaps provide new insight for any future research that could further explain this reported occurrence of toxic exposure. (C) 1997 Elsevier Science Ireland Ltd. RP Grant, PM (reprint author), LAWRENCE LIVERMORE NATL LAB,FORENS SCI CTR,L371,LIVERMORE,CA 94550, USA. NR 51 TC 7 Z9 7 U1 0 U2 1 PU ELSEVIER SCI IRELAND LTD PI CLARE PA CUSTOMER RELATIONS MANAGER, BAY 15, SHANNON INDUSTRIAL ESTATE CO, CLARE, IRELAND SN 0379-0738 J9 FORENSIC SCI INT JI Forensic Sci.Int. PD JUN 23 PY 1997 VL 87 IS 3 BP 219 EP 237 DI 10.1016/S0379-0738(97)00076-5 PG 19 WC Medicine, Legal SC Legal Medicine GA XL678 UT WOS:A1997XL67800006 PM 9248041 ER PT J AU Brodsky, SJ Karliner, M AF Brodsky, SJ Karliner, M TI Intrinsic charm of vector mesons: A possible solution of the ''rho pi puzzle'' SO PHYSICAL REVIEW LETTERS LA English DT Article ID DECAYS; NUCLEON; PROTON AB An outstanding mystery of charmonium physics is why the J/psi decays prominently to pseudoscalar plus vector meson channels, such as J/psi --> rho pi and J/psi --> K*K, whereas the psi'(2S) does not. We show that such decays of J/psi and their suppression for psi'(2S) follow naturally from the existence of intrinsic charm \(q) over bar q (c) over bar c] Fock components of the light vector mesons. C1 TEL AVIV UNIV,RAYMOND & BEVERLY SACKLER FAC EXACT SCI,SCH PHYS & ASTRON,IL-69978 TEL AVIV,ISRAEL. RP Brodsky, SJ (reprint author), STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309, USA. NR 28 TC 84 Z9 84 U1 0 U2 2 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 JUN 23 PY 1997 VL 78 IS 25 BP 4682 EP 4685 DI 10.1103/PhysRevLett.78.4682 PG 4 WC Physics, Multidisciplinary SC Physics GA XJ269 UT WOS:A1997XJ26900004 ER PT J AU Ammar, R Baringer, P Bean, A Besson, D Coppage, D Darling, C Davis, R Hancock, N Kotov, S Kravchenko, I Kwak, N Anderson, S Kubota, Y Lattery, M ONeill, JJ Patton, S Poling, R Riehle, T Savinov, V Smith, A Alam, MS Athar, SB Ling, Z Mahmood, AH Severini, H Timm, S Wappler, F Anastassov, A Blinov, S Duboscq, JE Fujino, D Fulton, R Gan, KK Hart, T Honscheid, K Kagan, H Kass, R Lee, J Spencer, MB Sung, M Undrus, A Wanke, R Wolf, A Zoeller, MM Nemati, B Richichi, SJ Ross, WR Skubic, P Wood, M Bishai, M Fast, J Gerndt, E Hinson, JW Menon, N Miller, DH Shibata, EI Shipsey, IPJ Yurko, M Gibbons, L Johnson, SD Kwon, Y Roberts, S Thorndike, EH Jessop, CP Lingel, K Marsiske, H Perl, ML Schaffner, SF Ugolini, D Wang, R Zhou, X Coan, TE Fadeyev, V Korolkov, I Maravin, Y Narsky, I Shelkov, V Staeck, J Stroynowski, R Volobouev, I Ye, J Artuso, M Efimov, A Frasconi, F Gao, M Goldberg, M He, D Kopp, S Moneti, GC Mountain, R Mukhin, Y Schuh, S Skwarnicki, T Stone, S Viehhauser, G Xing, X Bartelt, J Csorna, SE Jain, V Marka, S Freyberger, A Gibaut, D Godang, R Kinoshita, K Lai, IC Pomianowski, P Schrenk, S Bonvicini, G Cinabro, D Greene, R Perera, LP Barish, B Chadha, M Chan, S Eigen, G Miller, JS OGrady, C Schmidtler, M Urheim, J Weinstein, AJ Wurthwein, F Asner, DM Bliss, DW Brower, WS Masek, G Paar, HP Gronberg, J Kutschke, R Lange, DJ Menary, S Morrison, RJ Nakanishi, S Nelson, HN Nelson, TK Qiao, C Richman, JD Roberts, D Ryd, A Tajima, H Witherell, MS Balest, R Behrens, BH Cho, K Ford, WT Park, H Rankin, P Roy, J Smith, JG Alexander, JP Bebek, C Berger, BE Berkelman, K Bloom, K Cassel, DG Cho, HA Coffman, DM Crowcroft, DS Dickson, M Drell, PS Ecklund, KM Ehrlich, R Elia, R Foland, AD Gaidarev, P Galik, RS Gittelman, B Gray, SW Hartill, DL Heltsley, BK Hopman, PI Jones, SL Kandaswamy, J Katayama, N Kim, PC Kreinick, DL Lee, T Liu, Y Ludwig, GS Masui, J Mevissen, J Mistry, NB Ng, CR Nordberg, E Ogg, M Patterson, JR Peterson, D Riley, D Soffer, A Ward, C Athanas, M Avery, P Jones, CD Lohner, M Prescott, C Yang, S Yelton, J Zheng, J Brandenburg, G Briere, RA Gao, YS Kim, DYJ Wilson, R Yamamoto, H Browder, TE Li, F Li, Y Rodriguez, JL Bergfeld, T Eisenstein, BI Ernst, J Gladding, GE Gollin, GD Hans, RM Johnson, E Karliner, I Marsh, MA Palmer, M Selen, M Thaler, JJ Edwards, KW Bellerive, A Janicek, R MacFarlane, DB McLean, KW Patel, PM Sadoff, AJ AF Ammar, R Baringer, P Bean, A Besson, D Coppage, D Darling, C Davis, R Hancock, N Kotov, S Kravchenko, I Kwak, N Anderson, S Kubota, Y Lattery, M ONeill, JJ Patton, S Poling, R Riehle, T Savinov, V Smith, A Alam, MS Athar, SB Ling, Z Mahmood, AH Severini, H Timm, S Wappler, F Anastassov, A Blinov, S Duboscq, JE Fujino, D Fulton, R Gan, KK Hart, T Honscheid, K Kagan, H Kass, R Lee, J Spencer, MB Sung, M Undrus, A Wanke, R Wolf, A Zoeller, MM Nemati, B Richichi, SJ Ross, WR Skubic, P Wood, M Bishai, M Fast, J Gerndt, E Hinson, JW Menon, N Miller, DH Shibata, EI Shipsey, IPJ Yurko, M Gibbons, L Johnson, SD Kwon, Y Roberts, S Thorndike, EH Jessop, CP Lingel, K Marsiske, H Perl, ML Schaffner, SF Ugolini, D Wang, R Zhou, X Coan, TE Fadeyev, V Korolkov, I Maravin, Y Narsky, I Shelkov, V Staeck, J Stroynowski, R Volobouev, I Ye, J Artuso, M Efimov, A Frasconi, F Gao, M Goldberg, M He, D Kopp, S Moneti, GC Mountain, R Mukhin, Y Schuh, S Skwarnicki, T Stone, S Viehhauser, G Xing, X Bartelt, J Csorna, SE Jain, V Marka, S Freyberger, A Gibaut, D Godang, R Kinoshita, K Lai, IC Pomianowski, P Schrenk, S Bonvicini, G Cinabro, D Greene, R Perera, LP Barish, B Chadha, M Chan, S Eigen, G Miller, JS OGrady, C Schmidtler, M Urheim, J Weinstein, AJ Wurthwein, F Asner, DM Bliss, DW Brower, WS Masek, G Paar, HP Gronberg, J Kutschke, R Lange, DJ Menary, S Morrison, RJ Nakanishi, S Nelson, HN Nelson, TK Qiao, C Richman, JD Roberts, D Ryd, A Tajima, H Witherell, MS Balest, R Behrens, BH Cho, K Ford, WT Park, H Rankin, P Roy, J Smith, JG Alexander, JP Bebek, C Berger, BE Berkelman, K Bloom, K Cassel, DG Cho, HA Coffman, DM Crowcroft, DS Dickson, M Drell, PS Ecklund, KM Ehrlich, R Elia, R Foland, AD Gaidarev, P Galik, RS Gittelman, B Gray, SW Hartill, DL Heltsley, BK Hopman, PI Jones, SL Kandaswamy, J Katayama, N Kim, PC Kreinick, DL Lee, T Liu, Y Ludwig, GS Masui, J Mevissen, J Mistry, NB Ng, CR Nordberg, E Ogg, M Patterson, JR Peterson, D Riley, D Soffer, A Ward, C Athanas, M Avery, P Jones, CD Lohner, M Prescott, C Yang, S Yelton, J Zheng, J Brandenburg, G Briere, RA Gao, YS Kim, DYJ Wilson, R Yamamoto, H Browder, TE Li, F Li, Y Rodriguez, JL Bergfeld, T Eisenstein, BI Ernst, J Gladding, GE Gollin, GD Hans, RM Johnson, E Karliner, I Marsh, MA Palmer, M Selen, M Thaler, JJ Edwards, KW Bellerive, A Janicek, R MacFarlane, DB McLean, KW Patel, PM Sadoff, AJ TI A measurement of the Michel parameters in leptonic decays of the tau SO PHYSICAL REVIEW LETTERS LA English DT Article ID ETA AB We have measured the spectral shape Michel parameters rho and eta using leptonic decays of the tau, recorded by the CLEO II detector. Assuming e-mu universality in the vectorlike couplings, we find rho(e mu) = 0.735 +/- 0.013 +/- 0.008 and eta(e mu) = -0.015 +/- 0.061 +/- 0.062, where the first error is statistical and the second systematic. We also present measurements for the parameters for e and mu final states separately. C1 UNIV MINNESOTA,MINNEAPOLIS,MN 55455. SUNY ALBANY,ALBANY,NY 12222. OHIO STATE UNIV,COLUMBUS,OH 43210. UNIV OKLAHOMA,NORMAN,OK 73019. PURDUE UNIV,W LAFAYETTE,IN 47907. UNIV ROCHESTER,ROCHESTER,NY 14627. STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309. SO METHODIST UNIV,DALLAS,TX 75275. VANDERBILT UNIV,NASHVILLE,TN 37235. SYRACUSE UNIV,SYRACUSE,NY 13244. VIRGINIA POLYTECH INST & STATE UNIV,BLACKSBURG,VA 24061. WAYNE STATE UNIV,DETROIT,MI 48202. CALTECH,PASADENA,CA 91125. UNIV CALIF SAN DIEGO,LA JOLLA,CA 92093. UNIV CALIF SANTA BARBARA,SANTA BARBARA,CA 93106. UNIV COLORADO,BOULDER,CO 80309. CORNELL UNIV,ITHACA,NY 14853. UNIV FLORIDA,GAINESVILLE,FL 32611. HARVARD UNIV,CAMBRIDGE,MA 02138. UNIV HAWAII MANOA,HONOLULU,HI 96822. UNIV ILLINOIS,CHAMPAIGN,IL 61801. CARLETON UNIV,OTTAWA,ON K1S 5B6,CANADA. INST PARTICLE PHYS,MONTREAL,PQ,CANADA. MCGILL UNIV,MONTREAL,PQ H3A 2T8,CANADA. ITHACA COLL,ITHACA,NY 14850. BINP,RU-630090 NOVOSIBIRSK,RUSSIA. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551. UNIV TEXAS,AUSTIN,TX 78712. RP Ammar, R (reprint author), UNIV KANSAS,LAWRENCE,KS 66045, USA. RI Schaffner, Stephen/D-1189-2011; Briere, Roy/N-7819-2014; Frasconi, Franco/K-1068-2016; OI Briere, Roy/0000-0001-5229-1039; Frasconi, Franco/0000-0003-4204-6587; Bean, Alice/0000-0001-5967-8674 NR 14 TC 12 Z9 12 U1 1 U2 2 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 JUN 23 PY 1997 VL 78 IS 25 BP 4686 EP 4690 DI 10.1103/PhysRevLett.78.4686 PG 5 WC Physics, Multidisciplinary SC Physics GA XJ269 UT WOS:A1997XJ26900005 ER PT J AU Abe, K Abe, K Akagi, T Allen, NJ Ash, WW Aston, D Baird, KG Baltay, C Band, HR Barakat, MB Baranko, G Bardon, O Barklow, TL Bashindzhagyan, GL Bazarko, AO BenDavid, R Benvenuti, AC Bilei, GM Bisello, D Blaylock, G Bogart, JR Bolen, B Bolton, T Bower, GR Brau, JE Breidenbach, M Bugg, WM Burke, D Burnett, TH Burrows, PN Busza, W Calcaterra, A Caldwell, DO Calloway, D Camanzi, B Carpinelli, M Cassell, R Castaldi, R Castro, A CavalliSforza, M Chou, A Church, E Cohn, HO Coller, JA Cook, V Cotton, R Cowan, RF Coyne, DG Crawford, G DOliveira, A Damerell, CJS Daoudi, M DeSangro, R DellOrso, R Dervan, PJ Dima, M Dong, DN Du, PYC Dubois, R Eisenstein, BI Elia, R Etzion, E Fahey, S Falciai, D Fan, C Fernandez, JP Fero, MJ Frey, R Furuno, K Gillman, T Gladding, G Gonzalez, S Hart, EL Harton, JL Hasan, A Hasegawa, Y Hasuko, K Hedges, SJ Hertzbach, SS Hildreth, MD Huber, J Huffer, ME Hughes, EW Hwang, H Iwasaki, Y Jackson, DJ Jacques, P Jaros, JA Johnson, AS Johnson, JR Johnson, RA Junk, T Kajikawa, R Kalelkar, M Kang, HJ Karliner, I Kawahara, H Kendall, HW Kim, YD King, ME King, R Kofler, RR Krishna, NM Kroeger, RS Labs, JF Langston, M Lath, A Lauber, JA Leith, DWGS Lia, V Liu, MX Liu, X Loreti, M Lu, A Lynch, HL Ma, J Mancinelli, G Manly, S Mantovani, G Markiewicz, TW Maruyama, T Masuda, H Mazzucato, E McKemey, AK Meadows, BT Messner, R Mockett, PM Moffeit, KC Moore, TB Muller, D Nagamine, T Narita, S Nauenberg, U Neal, H Nussbaum, M Ohnishi, Y Osborne, LS Panvini, RS Park, CH Park, H Pavel, TJ Peruzzi, I Piccolo, M Piemontese, L Pieroni, E Pitts, KT Plano, RJ Prepost, R Prescott, CY Punkar, GD Quigley, J Ratcliff, BN Reeves, TW Reidy, J Reinertsen, PL Rensing, PE Rochester, LS Rowson, PC Russell, JJ Saxton, OH Schalk, T Schindler, RH Schumm, BA Sen, S Serbo, VV Shaevitz, MH Shank, JT Shapiro, G Sherden, DJ Shmakov, KD Simopoulos, C Sinev, NB Smith, SR Smy, MB Snyder, JA Stamer, P Steiner, H Steiner, R Strauss, MG Su, D Suekane, F Sugiyama, A Suzuki, S Swartz, M Szumilo, A Takahashi, T Taylor, FE Torrence, E Trandafir, AI Turk, JD Usher, T Vavra, J Vannini, C Vella, E Venuti, JP Verdier, R Verdini, PG Wagner, DL Wagner, SR Waite, AP Watts, SJ Weidemann, AW Weiss, ER Whitaker, JS White, SL Wickens, FJ Williams, DA Williams, DC Williams, SH Willocq, S Wilson, RJ Wisniewski, WJ Woods, M Word, GB Wyss, J Yamamoto, RK Yamartino, JM Yang, X Yashima, J Yellin, SJ Young, CC Yuta, H Zapalac, G Zdarko, RW Zhou, J AF Abe, K Abe, K Akagi, T Allen, NJ Ash, WW Aston, D Baird, KG Baltay, C Band, HR Barakat, MB Baranko, G Bardon, O Barklow, TL Bashindzhagyan, GL Bazarko, AO BenDavid, R Benvenuti, AC Bilei, GM Bisello, D Blaylock, G Bogart, JR Bolen, B Bolton, T Bower, GR Brau, JE Breidenbach, M Bugg, WM Burke, D Burnett, TH Burrows, PN Busza, W Calcaterra, A Caldwell, DO Calloway, D Camanzi, B Carpinelli, M Cassell, R Castaldi, R Castro, A CavalliSforza, M Chou, A Church, E Cohn, HO Coller, JA Cook, V Cotton, R Cowan, RF Coyne, DG Crawford, G DOliveira, A Damerell, CJS Daoudi, M DeSangro, R DellOrso, R Dervan, PJ Dima, M Dong, DN Du, PYC Dubois, R Eisenstein, BI Elia, R Etzion, E Fahey, S Falciai, D Fan, C Fernandez, JP Fero, MJ Frey, R Furuno, K Gillman, T Gladding, G Gonzalez, S Hart, EL Harton, JL Hasan, A Hasegawa, Y Hasuko, K Hedges, SJ Hertzbach, SS Hildreth, MD Huber, J Huffer, ME Hughes, EW Hwang, H Iwasaki, Y Jackson, DJ Jacques, P Jaros, JA Johnson, AS Johnson, JR Johnson, RA Junk, T Kajikawa, R Kalelkar, M Kang, HJ Karliner, I Kawahara, H Kendall, HW Kim, YD King, ME King, R Kofler, RR Krishna, NM Kroeger, RS Labs, JF Langston, M Lath, A Lauber, JA Leith, DWGS Lia, V Liu, MX Liu, X Loreti, M Lu, A Lynch, HL Ma, J Mancinelli, G Manly, S Mantovani, G Markiewicz, TW Maruyama, T Masuda, H Mazzucato, E McKemey, AK Meadows, BT Messner, R Mockett, PM Moffeit, KC Moore, TB Muller, D Nagamine, T Narita, S Nauenberg, U Neal, H Nussbaum, M Ohnishi, Y Osborne, LS Panvini, RS Park, CH Park, H Pavel, TJ Peruzzi, I Piccolo, M Piemontese, L Pieroni, E Pitts, KT Plano, RJ Prepost, R Prescott, CY Punkar, GD Quigley, J Ratcliff, BN Reeves, TW Reidy, J Reinertsen, PL Rensing, PE Rochester, LS Rowson, PC Russell, JJ Saxton, OH Schalk, T Schindler, RH Schumm, BA Sen, S Serbo, VV Shaevitz, MH Shank, JT Shapiro, G Sherden, DJ Shmakov, KD Simopoulos, C Sinev, NB Smith, SR Smy, MB Snyder, JA Stamer, P Steiner, H Steiner, R Strauss, MG Su, D Suekane, F Sugiyama, A Suzuki, S Swartz, M Szumilo, A Takahashi, T Taylor, FE Torrence, E Trandafir, AI Turk, JD Usher, T Vavra, J Vannini, C Vella, E Venuti, JP Verdier, R Verdini, PG Wagner, DL Wagner, SR Waite, AP Watts, SJ Weidemann, AW Weiss, ER Whitaker, JS White, SL Wickens, FJ Williams, DA Williams, DC Williams, SH Willocq, S Wilson, RJ Wisniewski, WJ Woods, M Word, GB Wyss, J Yamamoto, RK Yamartino, JM Yang, X Yashima, J Yellin, SJ Young, CC Yuta, H Zapalac, G Zdarko, RW Zhou, J TI Measurement of the tau neutrino helicity and Michel parameters in polarized e(+)e(-) collisions SO PHYSICAL REVIEW LETTERS LA English DT Article ID DECAY CORRELATIONS; Z->TAU(+)TAU(-); SLD AB We present a new measurement of the tau neutrino helicity h(nu tau) and the tau Michel parameters rho, eta, xi, and the product delta xi. The analysis exploits the highly polarized SLC electron beam to extract these quantities directly from a measurement of the tau decay spectra, using the 1993-1995 SLD data sample of 4328 e(+)e(-) --> Z(0) --> tau(+)tau(-) events. From the decays tau --> pi nu(tau) and tau --> rho nu(tau) we obtain a combined value h(nu tau) = -0.93 +/- 0.10 +/- 0.04. The leptonic decay channels yield combined values of rho = 0.72 +/- 0.09 +/- 0.03, xi = 1.05 +/- 0.35 +/- 0.04, and delta xi = 0.88 +/- 0.27 +/- 0.04. C1 ADELPHI UNIV, GARDEN CITY, NY 11530 USA. IST NAZL FIS NUCL, SEZIONE BOLOGNA, I-40126 BOLOGNA, ITALY. BOSTON UNIV, BOSTON, MA 02215 USA. BRUNEL UNIV, UXBRIDGE UB8 3PH, MIDDX, ENGLAND. UNIV CALIF SANTA BARBARA, SANTA BARBARA, CA 93106 USA. UNIV CALIF SANTA CRUZ, SANTA CRUZ, CA 95064 USA. UNIV CINCINNATI, CINCINNATI, OH 45221 USA. COLORADO STATE UNIV, FT COLLINS, CO 80523 USA. UNIV COLORADO, BOULDER, CO 80309 USA. COLUMBIA UNIV, NEW YORK, NY 10027 USA. IST NAZL FIS NUCL, SEZIONE FERRARA, I-44100 FERRARA, ITALY. UNIV FERRARA, I-44100 FERRARA, ITALY. IST NAZL FIS NUCL, LAB NAZL FRASCATI, I-00044 FRASCATI, ITALY. UNIV ILLINOIS, URBANA, IL 61801 USA. UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA. MIT, CAMBRIDGE, MA 02139 USA. UNIV MASSACHUSETTS, AMHERST, MA 01003 USA. UNIV MISSISSIPPI, UNIVERSITY, MS 38677 USA. MOSCOW MV LOMONOSOV STATE UNIV, INST NUCL PHYS, MOSCOW 119899, RUSSIA. NAGOYA UNIV, CHIKUSA KU, NAGOYA, AICHI 464, JAPAN. UNIV OREGON, EUGENE, OR 97403 USA. IST NAZL FIS NUCL, SEZIONE PADOVA, I-35100 PADUA, ITALY. UNIV PADUA, I-35100 PADUA, ITALY. IST NAZL FIS NUCL, SEZIONE PERUGIA, I-06100 PERUGIA, ITALY. UNIV PERUGIA, I-06100 PERUGIA, ITALY. IST NAZL FIS NUCL, SEZIONE PISA, I-56100 PISA, ITALY. UNIV PISA, I-56100 PISA, ITALY. RUTGERS STATE UNIV, PISCATAWAY, NJ 08855 USA. RUTHERFORD APPLETON LAB, DIDCOT OX11 0QX, OXON, ENGLAND. SOGANG UNIV, SEOUL, SOUTH KOREA. SOONGSIL UNIV, SEOUL 156743, SOUTH KOREA. STANFORD UNIV, STANFORD LINEAR ACCELERATOR CTR, STANFORD, CA 94309 USA. UNIV TENNESSEE, KNOXVILLE, TN 37996 USA. TOHOKU UNIV, SENDAI, MIYAGI 980, JAPAN. VANDERBILT UNIV, NASHVILLE, TN 37235 USA. UNIV WASHINGTON, SEATTLE, WA 98195 USA. UNIV WISCONSIN, MADISON, WI 53706 USA. YALE UNIV, NEW HAVEN, CT 06511 USA. UNIV GENOA, I-16146 GENOA, ITALY. RP Abe, K (reprint author), NAGOYA UNIV, CHIKUSA KU, NAGOYA, AICHI 464, JAPAN. RI de Sangro, Riccardo/J-2901-2012; Cavalli-Sforza, Matteo/H-7102-2015; Calcaterra, Alessandro/P-5260-2015; Frey, Raymond/E-2830-2016 OI de Sangro, Riccardo/0000-0002-3808-5455; Calcaterra, Alessandro/0000-0003-2670-4826; Frey, Raymond/0000-0003-0341-2636 NR 25 TC 19 Z9 19 U1 0 U2 2 PU AMER 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 JUN 23 PY 1997 VL 78 IS 25 BP 4691 EP 4696 DI 10.1103/PhysRevLett.78.4691 PG 6 WC Physics, Multidisciplinary SC Physics GA XJ269 UT WOS:A1997XJ26900006 ER PT J AU Zolotorev, M Budker, D AF Zolotorev, M Budker, D TI Parity nonconservation in relativistic hydrogenic ions SO PHYSICAL REVIEW LETTERS LA English DT Article ID ATOMS AB Possibilities of precision weak-interaction measurements in relativistic hydrogenic ions are considered. It is shown that using high-energy ion storage rings (RHIC, SPS, and LHC), and utilizing relativistic Doppler tuning and laser cooling, it is possible to achieve sensitivity necessary for testing physics beyond the standard model. C1 UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. RP Zolotorev, M (reprint author), UNIV CALIF BERKELEY,EO LAWRENCE BERKELEY NATL LAB,BERKELEY,CA 94720, USA. RI Budker, Dmitry/F-7580-2016 OI Budker, Dmitry/0000-0002-7356-4814 NR 12 TC 23 Z9 24 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 JUN 23 PY 1997 VL 78 IS 25 BP 4717 EP 4720 DI 10.1103/PhysRevLett.78.4717 PG 4 WC Physics, Multidisciplinary SC Physics GA XJ269 UT WOS:A1997XJ26900012 ER PT J AU Leonard, AW Mahdavi, MA Allen, SL Brooks, NH Fenstermacher, ME Hill, DN Lasnier, CJ Maingi, R Porter, GD Petrie, TW Watkins, JG West, WP AF Leonard, AW Mahdavi, MA Allen, SL Brooks, NH Fenstermacher, ME Hill, DN Lasnier, CJ Maingi, R Porter, GD Petrie, TW Watkins, JG West, WP TI Distributed divertor radiation through convection in DIII-D SO PHYSICAL REVIEW LETTERS LA English DT Article ID BOUNDARY AB The radiative dissipation of divertor target heat flux on DIII-D is shown to greatly exceed the limitations of energy transport dominated by electron thermal conduction parallel to the magnetic field. More than 80% of the power flowing into the outboard divertor is dissipated through radiation with a broad poloidal profile. It is shown that energy transport dominated by-convection over a large region of the divertor is consistent with the data. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551. OAK RIDGE ASSOCIATED UNIV,OAK RIDGE,TN 37831. SANDIA NATL LABS,LIVERMORE,CA 94551. RP Leonard, AW (reprint author), GEN ATOM CO,POB 85608,SAN DIEGO,CA 92186, USA. NR 21 TC 45 Z9 45 U1 0 U2 0 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 JUN 23 PY 1997 VL 78 IS 25 BP 4769 EP 4772 DI 10.1103/PhysRevLett.78.4769 PG 4 WC Physics, Multidisciplinary SC Physics GA XJ269 UT WOS:A1997XJ26900025 ER PT J AU Schilling, A Fisher, RA Phillips, NE Welp, U Kwok, WK Crabtree, GW AF Schilling, A Fisher, RA Phillips, NE Welp, U Kwok, WK Crabtree, GW TI Anisotropic latent heat of vortex-lattice melting in untwinned YBa2Cu3O7-delta SO PHYSICAL REVIEW LETTERS LA English DT Article ID HIGH-TEMPERATURE SUPERCONDUCTORS; LAYERED SUPERCONDUCTORS; TRANSITION; VORTICES; ORDER AB We report a distinct thermal signature of the first-order vortex-lattice melting for the external magnetic field H both parallel and perpendicular to the c axis of an untwinned YBa2Cu3O7-delta single crystal. Latent heats and discontinuities in specific heat were observed for each configuration. The entropies of melting and the melting lines H-m(T) both scale with an anisotropy parameter gamma approximate to 8. The specific heat of the vortex fluid is considerably larger than that of the vortex solid (by up to 2 mJ/mole K-2), which is not explained by simple arguments based on counting the numbers of thermodynamic degrees of freedom. C1 UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. ARGONNE NATL LAB,SCI & TECHNOL CTR SUPERCONDUCTIV,ARGONNE,IL 60439. RP Schilling, A (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 28 TC 143 Z9 143 U1 0 U2 5 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 JUN 23 PY 1997 VL 78 IS 25 BP 4833 EP 4836 DI 10.1103/PhysRevLett.78.4833 PG 4 WC Physics, Multidisciplinary SC Physics GA XJ269 UT WOS:A1997XJ26900041 ER PT J AU Yethiraj, M Paul, DM Tomy, CV Forgan, EM AF Yethiraj, M Paul, DM Tomy, CV Forgan, EM TI Neutron scattering study of the flux lattice in YNi2B2C SO PHYSICAL REVIEW LETTERS LA English DT Article ID SUPERCONDUCTIVITY; DIFFRACTION AB We observe a flux lattice with square symmetry in the superconductor YNi2B2C when the applied field is parallel to the c axis of the crystal. A square lattice observed previously by Yaron et al. in the isostructural magnetic analog ErNi2B2C was attributed to the interaction between magnetism in that system and the flux lattice. Since the Y-based compound does not order magnetically, it is clear that the structure of the flux lattice is unrelated to magnetic order. We do not observe any change in the mosaic or direction of the flux lines with applied field; these phenomena may be related to magnetism. In YNi2B2C, the strength of the flux lattice signal was seen to fall off rapidly with applied field; the results imply considerable disorder in the arrangement of the flux lines at 2.5 T, but are not consistent with melting. We see a markedly anisotropic flux lattice when the applied held is at 60 degrees to the c axis. In this case, the flux lattice is observed to be a distorted hexagon. C1 UNIV WARWICK,DEPT PHYS,COVENTRY CV4 7AL,W MIDLANDS,ENGLAND. UNIV BIRMINGHAM,SCH PHYS & SPACE RES,BIRMINGHAM B15 2TT,W MIDLANDS,ENGLAND. RP Yethiraj, M (reprint author), OAK RIDGE NATL LAB,DIV SOLID STATE,POB 2008,OAK RIDGE,TN 37831, USA. NR 17 TC 77 Z9 77 U1 0 U2 5 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 JUN 23 PY 1997 VL 78 IS 25 BP 4849 EP 4852 DI 10.1103/PhysRevLett.78.4849 PG 4 WC Physics, Multidisciplinary SC Physics GA XJ269 UT WOS:A1997XJ26900045 ER PT J AU Zheludev, A Maslov, S Shirane, G Sasago, Y Koide, N Uchinokura, K AF Zheludev, A Maslov, S Shirane, G Sasago, Y Koide, N Uchinokura, K TI Field-induced commensurate-incommensurate phase transition in a Dzyaloshinskii-Moriya spiral antiferromagnet SO PHYSICAL REVIEW LETTERS LA English DT Article ID NEUTRON-SCATTERING AB We report an observation of a commensurate-incommensurate phase transition in a Dzyaloshinskii-Moriya spiral magnet Ba2CuGe2O7. The transition is induced by applying a magnetic field in the plane of spin rotation. In this experiment we have direct control over the strength of the commensurate potential, while the preferred incommensurate period of the spin system remains unchanged. Experimental results for the period of the soliton lattice and bulk magnetization as a function of external magnetic field are in quantitative agreement with theory. C1 UNIV TOKYO,DEPT APPL PHYS,BUNKYO KU,TOKYO 113,JAPAN. RP Zheludev, A (reprint author), BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973, USA. RI Maslov, Sergei/C-2397-2009 OI Maslov, Sergei/0000-0002-3701-492X NR 23 TC 47 Z9 47 U1 2 U2 21 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 JUN 23 PY 1997 VL 78 IS 25 BP 4857 EP 4860 DI 10.1103/PhysRevLett.78.4857 PG 4 WC Physics, Multidisciplinary SC Physics GA XJ269 UT WOS:A1997XJ26900047 ER PT J AU Lee, WWL Qian, Q Davidson, RC AF Lee, WWL Qian, Q Davidson, RC TI Stability and transport properties of an intense ion beam propagating through an alternating-gradient focusing lattice SO PHYSICS LETTERS A LA English DT Article DE ion beam; space charge; particle simulation; stability; transport ID SIMULATION; FIELD AB Stability and transport properties of an intense ion beam propagating through an alternating-gradient focusing lattice with initial Kapchinskij-Vladimirskij (KV) distribution are studied using newly-developed perturbative (delta f) particle simulation techniques. Stability properties are investigated over a wide range of beam current and focusing field strength. In the unstable region, large-amplitude density perturbations with low azimuthal harmonic numbers, concentrated near the beam surface, are observed. Their nonlinear consequences are discussed. (C) 1997 Published by Elsevier Science B.V. RP Lee, WWL (reprint author), PRINCETON UNIV,PRINCETON PLASMA PHYS LAB,POB 451,PRINCETON,NJ 08543, USA. NR 16 TC 27 Z9 26 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9601 J9 PHYS LETT A JI Phys. Lett. A PD JUN 23 PY 1997 VL 230 IS 5-6 BP 347 EP 352 DI 10.1016/S0375-9601(97)00275-2 PG 6 WC Physics, Multidisciplinary SC Physics GA XG328 UT WOS:A1997XG32800015 ER PT J AU Brock, LR Rohlfing, EA AF Brock, LR Rohlfing, EA TI Spectroscopic studies of the (B)over-tilde(2)A''-(X)over-tilde(2)A'' system of the jet-cooled vinoxy radical SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID LASER-INDUCED GRATINGS; GAS-PHASE REACTIONS; SUPERSONIC FREE JET; UNIMOLECULAR DISSOCIATION; FLUORESCENCE; SPECTRUM; O-2; PHOTOLYSIS; TRANSITION; CONSTANTS AB We apply several techniques to the study of the (B) over tilde(2)A ''-(X) over tilde-(2)A '' band system of the jet-cooled vinery radical, CH2CHO. Vibronically resolved excitation spectra are obtained using both laser-induced fluorescence (LIF) and a two-color resonant four-wave mixing (TC-RFWM) scheme that provides the nonlinear equivalent of hole-burning spectra. Rotationally resolved LIF spectra recorded at low temperatures (less than or equal to 3 K) provide rotational constants for 9 (B) over tilde-state levels. We also measure the fluorescence lifetimes of 19 (B) over tilde-state levels and obtain high-quality dispersed fluorescence (DF) spectra from seven of the most strongly fluorescing levels in the (B) over tilde state. The excitation and DF spectra reveal far more vibrational levels in the two electronic states than have been previously observed. In total, we provide assignments for 54 levels observed in the first 3650 cm(-1) of the (B) over tilde state and for 57 levels in the first 3100 cm(-1) of the (X) over tilde state. These assignments include the identification of the alpha' fundamentals for nu(4) through nu(9) and all three alpha '' overtones, 2 nu(10) through 2 nu(12) in both states. The differences between the TC-RFWM and LIF spectra and the measured lifetimes indicate a dramatic increase in the predissociation rate of the (B) over tilde state beginning at 1190 cm(-1) above the origin. The predissociation rate is markedly mode-specific and is enhanced by out-of-plane excitation, possibly due to vibronic coupling with either the (A) over tilde(2)A' or (C) over tilde(2)A' electronic states, The congestion and complexity of the DF spectra at high energies provides direct evidence of extensive intramolecular vibrational redistribution on the ground-state potential surface. (C) 1997 American Institute of Physics. RP Brock, LR (reprint author), SANDIA NATL LABS,COMBUST RES FACIL,LIVERMORE,CA 94551, USA. NR 52 TC 47 Z9 48 U1 0 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 JUN 22 PY 1997 VL 106 IS 24 BP 10048 EP 10065 DI 10.1063/1.474091 PG 18 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA XE593 UT WOS:A1997XE59300007 ER PT J AU Osborn, DL Mordaunt, DH Choi, H Bise, RT Neumark, DM Rohlfing, CM AF Osborn, DL Mordaunt, DH Choi, H Bise, RT Neumark, DM Rohlfing, CM TI Photodissociation spectroscopy and dynamics of the HCCO free radical SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID FLASH KINETIC SPECTROSCOPY; LASER-INDUCED FLUORESCENCE; FLIGHT MASS-SPECTROMETER; KETENYL RADICALS; ATOMIC OXYGEN; O+C2H2(C2D2) REACTION; BRANCHING RATIO; AND/OR X(2)PI); MOLECULAR-BEAM; RATE-CONSTANT AB The photodissociation spectroscopy and dynamics of the HCCO radical have been investigated using fast radical beam photofragment translational spectroscopy. An electronic band with origin at 33 424 cm(-1) has been identified. This band exhibits rotational resolution near the band origin, but the well-defined rovibronic structure is homogeneously broadened at higher photon energies. Based on the rotational structure this band is assigned to the (B) over tilde(2) Pi <-- (2)A '' transition. Photofragment translational energy and angular distributions were obtained at several excitation energies. At excitation energies close to the origin, the excited, spin-forbidden CH(alpha (4) Sigma(-))+CO channel dominates, while the ground state CH(X-2 Pi)+CO channel is the major channel at higher photon energies, The translational energy distributions provide evidence of competition between intersystem crossing and internal conversion dissociation mechanisms, with some evidence for nonstatistical dynamics in the CH(X-2 Pi)+CO channel. This work yields an improved heat of formation for HCCO, Delta H-f,298(0) = 1.83+/-0.03 eV. (C) 1997 American Institute of Physics. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. SANDIA NATL LABS,COMBUST RES FACIL,LIVERMORE,CA 94551. RP Osborn, DL (reprint author), UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720, USA. RI Osborn, David/A-2627-2009; Neumark, Daniel/B-9551-2009 OI Neumark, Daniel/0000-0002-3762-9473 NR 79 TC 62 Z9 63 U1 2 U2 9 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 JUN 22 PY 1997 VL 106 IS 24 BP 10087 EP 10098 DI 10.1063/1.474064 PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA XE593 UT WOS:A1997XE59300010 ER PT J AU Field, RW Gittins, CM AF Field, RW Gittins, CM TI Realistic representation of the induced electric dipole moment of a polarizable ligand: The missing factor in the Rittner polarization model SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ALKALINE-EARTH MONOHALIDES; ENERGIES; CALCIUM AB We present a simple modification of the Rittner polarization model(1) to better represent the dipole moment of a negative ion induced by the electric field of its counterion. At high fields the traditional second-order perturbation theory treatment of ion polarization is not appropriate. The internuclear separation dependence of the induced dipole moment is better described by explicitly modeling the mixing of free ion basis states, The dipole moment function of the ion is evaluated using the ab initio value of the free ion polarizability and its experimentally determined electron affinity, We present a simple and quantitative resolution of the mysterious difference between ab initio polarizabilities and Rittner model-derived values, which previously had been optimized separately for every different counterion. (C) 1997 American Institute of Physics. C1 SANDIA NATL LABS,COMBUST RES FACIL,LIVERMORE,CA 94551. RP Field, RW (reprint author), MIT,DEPT CHEM,CAMBRIDGE,MA 02139, USA. NR 14 TC 9 Z9 9 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 JUN 22 PY 1997 VL 106 IS 24 BP 10379 EP 10382 DI 10.1063/1.474107 PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA XE593 UT WOS:A1997XE59300040 ER PT J AU Skinner, CJ Meixner, M Bode, MF Davis, RJ Dougherty, SM Drake, SA Arens, JF Jernigan, JG AF Skinner, CJ Meixner, M Bode, MF Davis, RJ Dougherty, SM Drake, SA Arens, JF Jernigan, JG TI Circumstellar environments .5. The asymmetric chromosphere and dust shell of alpha Orionis SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE stars, chromospheres; circumstellar matter; stars, individual, alpha Ori; supergiants; infrared, stars ID EVOLVED STARS; MASS-LOSS; EMISSION; RESOLUTION; INTERFEROMETRY; SUPERGIANTS; ENVELOPES; GRAINS; MIRA AB We report new mid-infrared and radio images of the M supergiant alpha Orionis. The radio images, taken with MERLIN1 and the Very Large Array, resolve the chromosphere of the star at a wavelength of 6 cm, showing that the radio-emitting region has between two and three times the diameter of the optical photosphere. The infrared images, taken at the UK Infrared Telescope (UKIRT) using the Berkeley Infrared Camera, show that the dust shell is resolved, Images taken one year apart show great changes in morphology, which suggests that the dust shell is being asymmetrically illuminated by a stellar radiation field that is strongly affected by the presence and evolution of spots on the stellar surface. We present a new model of the circumstellar environment of the star, which fits the infrared and radio images and the spectral energy distribution (SED), and is consistent with recently reported Hubble Space Telescope observations. The chromospheric structure is determined quantitatively and the inner dust shell structure qualitatively with this model. We find that the inner radius of the dust shell is approximately 0.5 arcsec, which disagrees with a number of interferometric measurements that have resulted in an inner radius close to 1.0 arcsec, We are unable to explain this differenc. C1 LAWRENCE LIVERMORE NATL LAB,INST GEOPHYS & PLANETARY PHYS,LIVERMORE,CA 94551. UNIV CALGARY,CALGARY,AB T2N 1N4,CANADA. LIVERPOOL JOHN MOORES UNIV,SCH ENGN ELECT & PHYS,ASTROPHYS GRP,LIVERPOOL L3 3AF,MERSEYSIDE,ENGLAND. UNIV ILLINOIS,DEPT AGRON,URBANA,IL 61801. NUFFIELD RADIO ASTRON OBSERV LABS,MACCLESFIELD SK11 9DL,CHESHIRE,ENGLAND. NASA,GODDARD SPACE FLIGHT CTR,HEASARC,GREENBELT,MD 20771. UNIV CALIF BERKELEY,SPACE SCI LAB,BERKELEY,CA 94720. NR 35 TC 25 Z9 25 U1 0 U2 0 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0NE SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD JUN 21 PY 1997 VL 288 IS 2 BP 295 EP 306 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA XH567 UT WOS:A1997XH56700006 ER PT J AU Knott, RB Smith, GC Watt, G Boldeman, JW AF Knott, RB Smith, GC Watt, G Boldeman, JW TI A large 2D PSD for thermal neutron detection SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 4th International Conference on Position-Sensitive Detectors CY SEP 09-13, 1996 CL MANCHESTER, ENGLAND ID WIRE AB A 2D PSD based on a MWPC has been constructed for a small angle neutron scattering instrument. The active area of the detector was 640 x 640 mm(2). To meet the specifications for neutron detection efficiency and spatial resolution, and to minimise parallax, the gas mixture was 190 kPa He-3 plus 100 kPa CF4, and the active volume had a thickness of 30 mm. The design maximum neutron count rate of the detector was 10(5) events per second. The (calculated) neutron detection efficiency was 60% for 2 Angstrom neutrons and the (measured) neutron energy resolution on the anode grid war typically 20% (fwhm). The location of a neutron detection event within the active area was determined using the wire-by-wire method: the spatial resolution (5 x 5 mm(2)) was thereby defined by the wire geometry. A 16-channel charge-sensitive preamplifier/amplifier/comparator module has been developed with a channel sensitivity of 0.1 V/fC, noise line width of 0.4 fC (fwhm) and channel-to-channel cross-talk of less than 5%. The Proportional Counter Operating System (PCOS III) (LeCroy Corp, USA) was used for event encoding. The ECL signals produced by the 16 channel modules were latched in PCOS III by a trigger pulse from the anode and the fast encoders produce a position and width for each event. The information was transferred to a UNIX workstation for accumulation and online display. C1 BROOKHAVEN NATL LAB,INSTRUMENTAT DIV,UPTON,NY 11973. RP Knott, RB (reprint author), AUSTRALIAN NUCL SCI & TECHNOL ORG,DIV PHYS,PRIVATE MAIL BAG,MENAI,NSW 2234,AUSTRALIA. NR 13 TC 8 Z9 9 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 21 PY 1997 VL 392 IS 1-3 BP 62 EP 67 DI 10.1016/S0168-9002(97)00270-2 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XU981 UT WOS:A1997XU98100012 ER PT J AU Kapustinsky, J Boissevain, J Bosze, E Britton, C Chang, J Clark, D Emery, M Ericson, N Fung, SY Jacak, B Jaffe, D Marek, L Seto, R SimonGillo, J Simpson, M Smith, R Sullivan, J Takahashi, Y vanHecke, H Walker, J Xu, N AF Kapustinsky, J Boissevain, J Bosze, E Britton, C Chang, J Clark, D Emery, M Ericson, N Fung, SY Jacak, B Jaffe, D Marek, L Seto, R SimonGillo, J Simpson, M Smith, R Sullivan, J Takahashi, Y vanHecke, H Walker, J Xu, N TI A multiplicity-vertex detector for the PHENIX experiment at RHIC SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 4th International Conference on Position-Sensitive Detectors CY SEP 09-13, 1996 CL MANCHESTER, ENGLAND AB A Multiplicity-Vertex Detector (MVD) has been designed, and is in construction for the PHENIX Experiment at the Relativistic Heavy Ion Collider (RHIC). The 35 000 channel silicon detector is a two-layer barrel comprised of 112 strip detectors, and two disk-shaped endcaps comprised of 24 wedge-shaped pad detectors. The support structure of the MVD is very low mass, only 0.4% of a radiation length in the central barrel. The detector front-end electronics are a custom CMOS chip set containing preamplifier, discriminator, analog memory unit, and analog-to-digital converter. The system has pipelined acquisition, performs in simultaneous read/write mode, and is clocked by the 10 MHz beam crossing rate at RHIC. These die, together with a pair of commercial FPGAs that are used for control logic, are packaged in a mutlichip-module (MCM). The MCM will be fabricated in the High-Density-Interconnect (HDI) process. The prototype MCM design layout is described. C1 UNIV CALIF RIVERSIDE,RIVERSIDE,CA 92521. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. UNIV ALABAMA,HUNTSVILLE,AL 35899. RP Kapustinsky, J (reprint author), LOS ALAMOS NATL LAB,POB 1663,MAIL STOP H846,LOS ALAMOS,NM 87545, USA. RI Simpson, Michael/A-8410-2011 OI Simpson, Michael/0000-0002-3933-3457 NR 5 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 21 PY 1997 VL 392 IS 1-3 BP 192 EP 196 DI 10.1016/S0168-9002(97)00289-1 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XU981 UT WOS:A1997XU98100039 ER PT J AU Hoffberg, M Laird, R Lenkzsus, F Liu, CD Rodricks, B Gelbart, A AF Hoffberg, M Laird, R Lenkzsus, F Liu, CD Rodricks, B Gelbart, A TI The development of high-speed 100 fps CCD camera SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 4th International Conference on Position-Sensitive Detectors CY SEP 09-13, 1996 CL MANCHESTER, ENGLAND AB This paper describes the development of a high-speed CCD digital camera system. The system has been designed to use CCDs from various manufacturers with minimal modifications. The first camera built on this design utilizes a Thomson 512 x 512 pixel CCD as its sensor, which is read out from two parallel outputs at a speed of 15 MHz/pixel/output. The data undergo correlated double sampling after which it is digitized into 12 bits. The throughput of the system translates into 60 MB/second, which is either stored directly in a PC or transferred to a custom-designed VXI module. The PC data acquisition version of the camera can collect sustained data in real time that is limited to the memory installed in the PC. The VXI version of the camera, also controlled by a PC, stores 512 MB of real-time data before it must be read out to the PC disk storage. The uncooled CCD can be used either with lenses for visible light imaging or with a phosphor screen for X-ray imaging. This camera has been tested with a phosphor screen coupled to a fiber-optic face plate for high-resolution, high-speed X-ray imaging. The camera is controlled through a custom event-driven user-friendly Windows package. The pixel clock speed can be changed from 1 to 15 MHz. The noise was measured to be 1.05 bits at a 13.3 MHz pixel clock. This paper will describe the electronics, software, and characterizations that have been performed using both visible and X-ray photons. C1 ROCHESTER INST TECHNOL,ROCHESTER,NY 14623. RP Hoffberg, M (reprint author), ARGONNE NATL LAB,ADV PHOTON SOURCE,ARGONNE,IL 60439, USA. NR 11 TC 2 Z9 2 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 21 PY 1997 VL 392 IS 1-3 BP 214 EP 219 DI 10.1016/S0168-9002(97)00229-5 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XU981 UT WOS:A1997XU98100044 ER PT J AU Weisenberger, AG Majewski, S Saha, M Bradley, E AF Weisenberger, AG Majewski, S Saha, M Bradley, E TI Coincident radiation imaging of iodine 125 for in vivo gene imaging in small animals SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 4th International Conference on Position-Sensitive Detectors CY SEP 09-13, 1996 CL MANCHESTER, ENGLAND ID ANTISENSE OLIGODEOXYNUCLEOTIDES; IN-VIVO; EXPRESSION; PROBES; BRAIN AB Progress has been made towards a novel in vivo gene imaging technology which takes advantage of the emission properties of I-125 as the label for a gene specific probe. The radioisotope I-125 decays via electron capture emitting a 35 keV gamma-ray with the prompt emission of several 27-32 keV K alpha and K beta shell X-rays. Hence, a coincidence detection condition can be implemented to detect the I-125 decays, thus reducing the background contribution and enhancing the possibility of detecting minute amounts of the isotope. The detector system utilizes crystal scintillators and a position-sensitive photomultiplier tube. Currently, studies in molecular biology and gene regulation follow the expression of a particular gene at a given instant in time. Presently, in situ hybridization and immunochemical assays are available to observe the spatial patterning of gene expression in an organism at any one instant in time for one organism but one must sacrifice the organism to make a measurement, essentially taking a single snap-shot of the state of expression of the gene of interest. It is hoped that this detection scheme will make possible gene imaging in live animals for extended periods of time. C1 COLL WILLIAM & MARY,DEPT BIOL,WILLIAMSBURG,VA 23185. RP Weisenberger, AG (reprint author), THOMAS JEFFERSON NATL ACCELERATOR FACIL,DIV PHYS,MS12H,12000 JEFFERSON AVE,NEWPORT NEWS,VA 23606, USA. NR 11 TC 11 Z9 11 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 21 PY 1997 VL 392 IS 1-3 BP 299 EP 303 DI 10.1016/S0168-9002(97)00243-X PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XU981 UT WOS:A1997XU98100060 ER PT J AU GarciaSciveres, M AF GarciaSciveres, M TI Readout electronics architecture and packaging for the CDF silicon upgrade SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 4th International Conference on Position-Sensitive Detectors CY SEP 09-13, 1996 CL MANCHESTER, ENGLAND AB The CDF Collaboration is replacing its silicon vertex detector (SVX') with an enhanced, completely new detector (SVXII). The SVXII design seeks to improve upon SVX' in many aspects simultaneously. Unlike SVX', SVXII information will be used for a second level trigger, demanding the ability to read out the detector at a very high rate. Additionally, the interaction period will now be significantly shorter than the lowest level trigger latency, which requires the use of a data pipeline in the front end. A desire for greater acceptance than SVX' confines the SVXII readout electronics to be directly on active sensor area. This demands small size (high interconnection density) and low mass, while at the same time the faster electronics call for improved thermal performance. New ''deadtimeless'' readout electronics and packaging to meet the above needs are discussed in this article. Preliminary results on performance of prototypes are presented. RP GarciaSciveres, M (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,MS 50B-5239,1 CYCLOTRON RD,BERKELEY,CA 94720, USA. NR 6 TC 8 Z9 8 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 21 PY 1997 VL 392 IS 1-3 BP 375 EP 379 DI 10.1016/S0168-9002(97)00248-9 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XU981 UT WOS:A1997XU98100075 ER PT J AU Wojcik, R Majewski, S AF Wojcik, R Majewski, S TI Single shot dual energy reverse geometry X-radiography SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 4th International Conference on Position-Sensitive Detectors CY SEP 09-13, 1996 CL MANCHESTER, ENGLAND ID DIGITAL RADIOGRAPHY AB Reverse Geometry X-radiography (RGX)(1) imaging uses a unique configuration of X-ray source, object, and X-ray detector to produce nearly scatter-free high-resolution digital images. With the system produced by Digiray, one can obtain a resolution of over 7 1p/mm with an acquisition lime of 1 s for a 1024 x 1024 resolution scan covering a 25 cm diameter area. The simplicity of the detector required for imaging allows more advanced radiographic imaging techniques to be easily and inexpensively employed such as dual energy imaging. RP Wojcik, R (reprint author), THOMAS JEFFERSON NATL ACCELERATOR FACIL,JEFFERSON LAB,DETECTOR GRP,12000 JEFFERSON AV,NEWPORT NEWS,VA 23606, USA. NR 11 TC 0 Z9 0 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 21 PY 1997 VL 392 IS 1-3 BP 475 EP 478 DI 10.1016/S0168-9002(97)00282-9 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XU981 UT WOS:A1997XU98100092 ER PT J AU Dodelson, S AF Dodelson, S TI Determining cosmic microwave background anisotropies in the presence of foregrounds SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmic microwave background; cosmology, observations; methods, statistical ID DEGREE ANGULAR SCALES; RADIATION AB Separating foregrounds from the signal is one of the major challenges in cosmic microwave background (CMB) experiments. A simple way to estimate the CMB temperature in a given pixel is to fit for the amplitudes of the CMB and the various foreground components. The variance squared of this estimator is shown to be equal to (FDF)(2) sigma(theta)((0)2) + sigma(shape)(2)s where sigma(theta)((0)) is the variance in the absence of foregrounds, sigma(shape) is the variance due to the uncertainty in the shapes of the foreground components, and FDF is the foreground degradation factor. This one number, the FDF, gives a good indication of the ability of a given experiment to disentangle the CMB from foreground sources. A variety of applications relating to the planning and analyzing of experiments is presented. This approach, viz., analyzing the variance, can be used to assess the usefulness of any estimator. RP Dodelson, S (reprint author), FERMILAB NATL ACCELERATOR LAB,NASA FERMILAB ASTROPHYS CTR,POB 500,BATAVIA,IL 60510, USA. NR 17 TC 20 Z9 20 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 20 PY 1997 VL 482 IS 2 BP 577 EP 587 DI 10.1086/304157 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA XF541 UT WOS:A1997XF54100002 ER PT J AU Hunter, JH Whitaker, RW Lovelace, RVE AF Hunter, JH Whitaker, RW Lovelace, RVE TI Kelvin-Helmholtz and thermal-dynamic instabilities with self-gravity: A new gravitational interface instability SO ASTROPHYSICAL JOURNAL LA English DT Article DE hydrodynamics; instabilities; ISM, clouds; stars, formation ID INTERSTELLAR-MEDIUM; CLOUDS; GAS AB In the vortex sheet limit, we generalize our previous work on compressible, anisentropic Kelvin-Helmholtz, and related instabilities by including self-gravity in the calculations. In addition to significantly modifying the Kelvin-Helmholtz modes, if the background media are of unequal density, self-gravity gives rise to a new instability that persists in the static limit. If the media have significant density contrast (rho(1)/rho(2)=1/2, say), the growth rate of this new gravitational interface instability is of the order of the free-fall time in the denser medium, and, unlike a Jeans instability, it depends only weakly on the perturbation wavelength. Such instabilities may initiate star formation near the boundaries of molecular clouds in the ISM on timescales of similar to 10(6)-10(7) yr. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. CORNELL UNIV,DEPT APPL PHYS,ITHACA,NY 14853. CORNELL UNIV,DEPT ASTRON,ITHACA,NY 14853. RP Hunter, JH (reprint author), UNIV FLORIDA,DEPT ASTRON,POB 112005,GAINESVILLE,FL 32611, USA. NR 17 TC 9 Z9 9 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 20 PY 1997 VL 482 IS 2 BP 852 EP 865 PN 1 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA XF541 UT WOS:A1997XF54100023 ER PT J AU Meixner, M Skinner, CJ Graham, JR Keto, E Jernigan, JG Arens, JF AF Meixner, M Skinner, CJ Graham, JR Keto, E Jernigan, JG Arens, JF TI Axially symmetric superwinds of proto-planetary nebulae with 21 micron dust features SO ASTROPHYSICAL JOURNAL LA English DT Article DE circumstellar matter; infrared, ISM, continuum; stars, AGB and post-AGB; stars, mass loss ID POST-AGB STARS; EMISSION FEATURES; INFRARED-SPECTRA; IRAS 21282+5050; CO OBSERVATIONS; RED-RECTANGLE; CARBON; EVOLUTION; IRAS-21282+5050; 10-MU-M AB We present narrowband images at selected wavelengths in the 8-13 mu m window of four carbon-rich, proto-planetary nebulae that have an unusual 21 mu m dust feature: IRAS 04296+3429, IRAS 22272+5435, IRAS 07134+1005, and IRAS 19500-1709. We observe axially symmetric dust emission structures in IRAS 22272+5435 and IRAS 07134+1005, and tentatively in IRAS 19500-1709, while IRAS 04296+3429 is unresolved with our similar to 1'' angular resolution. The well-resolved morphology of IRAS 07134+1005 shows an elliptical outer shell surrounding two aligned peaks that we interpret as limb-brightened peaks of an optically thin, elliptical shell with an equatorial density enhancement. This mid-IR morphology contrasts with that observed in the better studied carbon-rich proto-planetary nebulae, AFGL 2688, AFGL 915, and AFGL 618, which show bright, unresolved cores, probably created by optically thick inner regions, and bipolar extensions that align with their optical reflection nebulosities. Using an axially symmetric dust code and assuming that the dust is composed of 0.01 mu m amorphous carbon grains, we model the dust emission images and the spectral energy distributions of these four proto-planetary nebulae and of the young, carbon-rich planetary nebula IRAS 21282+5050, which also has an axially symmetric dust shell and other similarities with the proto-planetary nebulae that have the 21 mu m dust feature. Marginally resolved mid-infrared images constrain the dust shell's inner radius, while well-resolved mid-infrared images additionally constrain other geometric parameters of the model (e.g., inclination angles and pole-to-equator mass-loss rate ratios). The modeling reveals that the observed axial symmetry in the dust shells of these objects coincides with an enhanced mass-loss phase (similar to 3 x 10(-5) M. yr(-1)) during which the equatorial mass-loss rate was a factor of 18-90 higher than the polar mass-loss rate, i.e., an axially symmetric superwind. Our dynamical age estimates indicate that these stars left the asymptotic giant branch approximately 300-1400 years ago, just after the superwind phase. For each object, the size and structure of the dust shell is the same for the sampled wavelengths, with the exception of IRAS 22272+5435 for which the 11.8 mu m emission is larger than either the 8.2 or the 9.7 mu m emission. IRAS 22272+5435's spectrum has a larger dust feature-to-dust continuum ratio than found in the other objects, and hence its 11.8 mu m image is probably dominated by the 11.8 mu m feature emission that has different optical properties than the underlying continuum. C1 LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA USA. UNIV ILLINOIS, DEPT ASTRON, MC 221, URBANA, IL 61801 USA. SPACE TELESCOPE SCI INST, BALTIMORE, MD 21218 USA. SMITHSONIAN ASTROPHYS OBSERV, CAMBRIDGE, MA 02138 USA. UNIV CALIF BERKELEY, SPACE SCI LAB, BERKELEY, CA 94720 USA. RP UNIV CALIF BERKELEY, DEPT ASTRON, BERKELEY, CA 94720 USA. NR 61 TC 82 Z9 82 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD JUN 20 PY 1997 VL 482 IS 2 BP 897 EP 912 DI 10.1086/304174 PN 1 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA XF541 UT WOS:A1997XF54100029 ER PT J AU Mathews, GJ Wilson, JR AF Mathews, GJ Wilson, JR TI Binary-induced neutron star compression, heating, and collapse SO ASTROPHYSICAL JOURNAL LA English DT Article DE binaries, close; gamma rays, theory; stars, evolution; stars, interiors; stars, neutron ID OBSERVATIONAL CONSTRAINTS; GRAVITATIONAL-RADIATION; SUPERNOVAE; BURST; MASS AB We analyze several aspects of the recently noted neutron star collapse instability in close binary systems. We utilize (3 + 1) dimensional and spherical numerical general relativistic hydrodynamics to study the origin, evolution, and parametric sensitivity of this instability. We derive the modified conditions of hydrostatic equilibrium for the stars in the curved space of quasi-static orbits. We examine the sensitivity of the instability to the neutron star mass and equation of state. We also estimate limits to the possible interior heating and associated neutrino luminosity that could be generated as the stars gradually compress prior to collapse. We show that the radiative loss in neutrinos from this heating could exceed the power radiated in gravity waves for several hours prior to collapse. The possibility that the radiation neutrinos could produce gamma-ray (or other electromagnetic) burst phenomena is also discussed. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP Mathews, GJ (reprint author), UNIV NOTRE DAME,DEPT PHYS,NOTRE DAME,IN 46556, USA. NR 29 TC 29 Z9 29 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 20 PY 1997 VL 482 IS 2 BP 929 EP 941 DI 10.1086/304166 PN 1 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA XF541 UT WOS:A1997XF54100032 ER PT J AU Decaux, V Beiersdorfer, P Kahn, SM Jacobs, VL AF Decaux, V Beiersdorfer, P Kahn, SM Jacobs, VL TI High resolution measurement of the K alpha spectrum of Fe xxv-xviii: New spectral diagnostics of nonequilibrium astrophysical plasmas SO ASTROPHYSICAL JOURNAL LA English DT Article DE atomic data; atomic processes; methods, laboratory; plasmas ID SUPER-NOVA REMNANTS; BEAM ION-TRAP; LABORATORY PLASMAS; CROSS-SECTIONS; IRON; TEMPERATURE AB We present laboratory measurements of high-resolution spectra of iron I(a emission under transient ionization conditions similar to those that are believed to exist in stellar flares and young supernova remnants. Taking advantage of our high spectral resolution (lambda/Delta lambda greater than or equal to 2000, we identify a number of transitions that can serve as diagnostics of ionizing plasmas. By varying the excitation energy in the experiments, we constrain the effects of the electron distribution on these diagnostic lines. Using our measured line ratios, we deduce values for the ionization time, eta= N(e)t, in the plasma, which agree with the actual values to similar to 20% accuracy. This result gives us confidence to our ability to derive similar constraints on astrophysical plasmas from remote X-ray spectroscopic observations. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551. UNIV CALIF BERKELEY,DEPT PHYS & ASTRON,BERKELEY,CA 94720. UNIV CALIF BERKELEY,SPACE SCI LAB,BERKELEY,CA 94720. USN,RES LAB,COMPLEX SYST THEORY BRANCH,DIV CONDENSED MATTER & RADIAT SCI,WASHINGTON,DC 20375. NR 25 TC 53 Z9 54 U1 0 U2 4 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 20 PY 1997 VL 482 IS 2 BP 1076 EP 1084 DI 10.1086/304169 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA XF541 UT WOS:A1997XF54100044 ER PT J AU Smirnov, AV Bratkovsky, AM AF Smirnov, AV Bratkovsky, AM TI ''Switching''' and re-entrant behaviour of magnetisation in ultrathin films of fcc Co upon deposition of Cu SO EUROPHYSICS LETTERS LA English DT Article ID COBALT FILMS; ANISOTROPY; INTERFACE; TRANSITION; CR AB We analyse the easy magnetisation axis ''switching'' recently discovered in experiments on Co ultrathin films with a deposited submonolayer of Cu by ab initio methods. The present large-scale calculations show that the nanomagnetic pattern of a stepped Co(001) surface 2-3 monolayers thick with submonolayer quantities of Cu has a complex three-dimensional character. We show that the maximum non-collinearity of spin-directions is about 30 degrees, and the ''switching'' has a re-entrant character as a function of Cu coverage. C1 HEWLETT PACKARD LABS,PALO ALTO,CA 94304. RP Smirnov, AV (reprint author), IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011, USA. NR 26 TC 0 Z9 0 U1 0 U2 0 PU EDITIONS PHYSIQUE PI LES ULIS CEDEX PA Z I DE COURTABOEUF AVE 7 AV DU HOGGAR, BP 112, 91944 LES ULIS CEDEX, FRANCE SN 0295-5075 J9 EUROPHYS LETT JI Europhys. Lett. PD JUN 20 PY 1997 VL 38 IS 9 BP 693 EP 698 DI 10.1209/epl/i1997-00304-5 PG 6 WC Physics, Multidisciplinary SC Physics GA XG260 UT WOS:A1997XG26000009 ER PT J AU Kleinke, H Franzen, HF AF Kleinke, H Franzen, HF TI The Co/P exchange in Hf5Co1+xP3-x and its consequences for the electronic structure and magnetic properties SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article DE Co/P substitution; electronic structure; magnetic properties; phosphides ID FE2TA9S6; CO2TA9S6; CLUSTERS AB The Co/P exchange observed in Hf5Co1+xP3-x is the first example for a statistical disordered Co/P occupancy on one position. In its crystal structure both different kinds of atoms, the late-transition metal atom Co and the nonmetal P, are located in trigonal prismatic voids of the Hf sublattice. The purely Co site has two P neighbours located in neighbouring trigonal prisms, each of which shares a rectangular face with the central Co prism, forming an infinite -Co-P- zigzag chain. The two other P sites have no contact to a Co atom. As a consequence of this, a partial substitution of P by Co on the sites which have shorter distances to the surrounding Hf atoms can take place. This P position can be occupied by up to 50% Co, leading to a significant phase range (0 less than or equal to x less than or equal to 0.5 in Hf5Co1+xP3-x). However, increasing the Co to P ratio brings a higher density of states at the Fermi level, corresponding to higher magnetic susceptibilities as determined experimentally. The consequences of the Co/P exchange for the electronic structure are discussed. C1 IOWA STATE UNIV,US DOE,AMES LAB,AMES,IA 50011. NR 19 TC 10 Z9 10 U1 0 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD JUN 20 PY 1997 VL 255 IS 1-2 BP 110 EP 116 DI 10.1016/S0925-8388(96)02840-X PG 7 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA XJ449 UT WOS:A1997XJ44900018 ER PT J AU Ng, DS Francone, OL Forte, TM Zhang, JL Haghpassand, M Rubin, EM AF Ng, DS Francone, OL Forte, TM Zhang, JL Haghpassand, M Rubin, EM TI Disruption of the murine lecithin:cholesterol acyltransferase gene causes impairment of adrenal lipid delivery and up-regulation of scavenger receptor class B type I SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID HIGH-DENSITY LIPOPROTEIN; APOPROTEIN-A-I; RAT; METABOLISM; DEFICIENCY; ESTERS; MICE AB Lecithin:cholesterol acyltransferase (LCAT) is the major determinant of the cholesteryl ester (CE) content of high density lipoprotein (HDL) in plasma, The selective uptake of HDL-CE is postulated to participate in delivery of tissue-derived cholesterol both to the liver and steroidogenic tissues. Recent studies comparing mice with similarly low levels of HDL, due to the absence of either of the two major HDL-associated apolipoproteins apoA-I and apoA-II, suggest that apoA-I is crucial in modulating this process, possibly through interaction with scavenger receptor class B type I (SR-BI), Because of the central role of LCAT in determining the size, lipid composition, and plasma concentration of HDL, we have created LCAT-deficient mice by gene targeting to examine the effect of:LCAT deficiency on HDL structure and composition and adrenal cholesterol delivery, The HDL in the LCAT-deficient mice was reduced in its plasma concentration (92%) and CE content (96%), The HDL particles were heterogeneous in size and morphology and included numerous discoidal particles, mimicking those observed in LCAT-deficient humans. The adrenals of the male Lcat (-/-) mice were severely depleted of lipid stores, which was associated with a 2-fold up-regulation of the adrenal SR-BI mRNA. These studies demonstrate that LCAT deficiency, similar to apoA-I deficiency, is associated with a. marked decrease in adrenal cholesterol delivery and supports the hypothesis that adrenal SR-BI expression is regulated by the adrenal cholesterol. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,CTR HUMAN GENOME,DIV LIFE SCI,BERKELEY,CA 94720. DEPT CARDIOVASC & METAB DIS,DIV CENT RES,GROTON,CT 06340. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,MOL MED RES PROGRAM,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DONNER LAB,BERKELEY,CA 94720. FU NHLBI NIH HHS [PPG HL 18574] NR 24 TC 109 Z9 111 U1 0 U2 4 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 JUN 20 PY 1997 VL 272 IS 25 BP 15777 EP 15781 DI 10.1074/jbc.272.25.15777 PG 5 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA XF329 UT WOS:A1997XF32900034 PM 9188474 ER PT J AU Berkowitz, CM Shaw, WJ AF Berkowitz, CM Shaw, WJ TI Airborne measurements of boundary layer chemistry during the southern oxidant study: A case study SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SOUTHEASTERN UNITED-STATES; OZONE FORMATION; RURAL SITE; MODELS; HYDROCARBONS; TROPOSPHERE; TRANSPORT; ATLANTA; IMPACT; NOY AB Measurements of chemical and meteorological variables were made at several altitudes over a surface chemistry site near Nashville, Tennessee, during the 1995 Southern Oxidants Study. The measurements were designed to reveal the effects of turbulent mixing on atmospheric chemistry. They were made under conditions of clear skies and light winds during the morning transition from nocturnal stable stratification to the afternoon convective mixed layer. Early morning ozone mixing ratios measured by the aircraft were similar to 70 parts per billion (ppb), while those measured by surface instrumentation were similar to 25 ppb. Corresponding to growth of the morning turbulent layer, surface ozone values steadily increased with time until they matched the 70 ppb values aloft by midmorning. The mixing ratios of isoprene at altitudes above the surface increased by several orders of magnitude with the onset of turbulence at each measurement altitude. The slope of O-3 as a function of NOy for each of the flight legs was also sensitive to the presence of turbulence. Measurements from nonturbulent flight legs yielded slopes that were considerably steeper than those from measurements made in turbulence. This study shows that the concentration of ozone precursors aloft is clearly dependent on the presence of turbulence, and turbulent mixing could explain the evolution of ozone concentrations at the surface. In general, conclusions regarding pollutant concentrations must account for both chemical and local dynamic processes. RP Berkowitz, CM (reprint author), PACIFIC NW LAB, POB 999,BATTELLE BLVD,MSIN K9-30, RICHLAND, WA 99352 USA. NR 31 TC 13 Z9 13 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 JUN 20 PY 1997 VL 102 IS 11D BP 12795 EP 12804 DI 10.1029/97JD00417 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA XG179 UT WOS:A1997XG17900002 ER PT J AU Taleb, DE McGraw, R Mirabel, P AF Taleb, DE McGraw, R Mirabel, P TI Time lag effects on the binary homogeneous nucleation of aerosols in the wake of an aircraft SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID ACID-WATER VAPOR; SULFURIC-ACID; CONTRAIL FORMATION; MIXTURES; KINETICS AB Steady state rates and time lags for binary homogeneous nucleation of sulfuric acid-water aerosols in aircraft wakes are calculated for relative humidities lower than 100%, i.e., for the case in which no visible contrails form. Formation of the sulfuric acid-water aerosol is shown to depend sensitively on the concentration of sulfuric acid derived from engine exhaust. Nucleation of the sulfuric acid-water aerosol is found to be controlled both by the steady state rate and by the time lag on the timescales relevant to contrail formation. Only for the highest gas-phase acid concentrations are the nucleation time lags sufficiently short that steady state conditions pertain. C1 BROOKHAVEN NATL LAB, ENVIRONM CHEM DIV, UPTON, NY 11973 USA. RP Taleb, DE (reprint author), UNIV STRASBOURG 1, CTR GEOCHIM SURFACE, 28 RUE GOETHE, F-67000 STRASBOURG, FRANCE. NR 32 TC 12 Z9 12 U1 1 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 JUN 20 PY 1997 VL 102 IS 11D BP 12885 EP 12890 DI 10.1029/97JD00608 PG 6 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA XG179 UT WOS:A1997XG17900010 ER PT J AU Sigalas, MM Biswas, R Li, Q Crouch, D Leung, W JacobsWoodbury, R Lough, B Nielsen, S McCalmont, S Tuttle, G Ho, KM AF Sigalas, MM Biswas, R Li, Q Crouch, D Leung, W JacobsWoodbury, R Lough, B Nielsen, S McCalmont, S Tuttle, G Ho, KM TI Dipole antennas on photonic band-gap crystals - Experiment and simulation SO MICROWAVE AND OPTICAL TECHNOLOGY LETTERS LA English DT Article DE photonic band-gap materials; dipole antennas; finite-difference time-domain calculations AB The radiation patterns of dipole antennas on three-dimensional photonic crystal substrates have been measured and calculated with the finite-difference-time-domain method. The photonic band-gap crystal behaves as a perfectly reflecting substrate, and all the dipole power is radiated into the air side when driven at frequencies in the stop band. The radiation pattern is found for different positions and orientations of the dipole antenna. Antenna configurations with desirable patterns are identified. (C) 1997 John Wiley & Sons, Inc. RP Sigalas, MM (reprint author), IOWA STATE UNIV,AMES LAB,MICROELECT RES CTR,DEPT PHYS & ASTRON,AMES,IA 50011, USA. NR 12 TC 53 Z9 53 U1 0 U2 2 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0895-2477 J9 MICROW OPT TECHN LET JI Microw. Opt. Technol. Lett. PD JUN 20 PY 1997 VL 15 IS 3 BP 153 EP 158 DI 10.1002/(SICI)1098-2760(19970620)15:3<153::AID-MOP10>3.3.CO;2-0 PG 6 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA XA515 UT WOS:A1997XA51500010 ER PT J AU Ma, NL Cheung, YS Ng, CY Li, WK AF Ma, NL Cheung, YS Ng, CY Li, WK TI Application of Gaussian-2 theory for the energetics of XO/XO+/XO- and XOH/XOH+ (X=F, Cl, Br, I) SO MOLECULAR PHYSICS LA English DT Article ID IONIZATION-ENERGY; BASIS-SETS; PHOTOELECTRON-SPECTROSCOPY; CONTAINING MOLECULES; 3RD-ROW ATOMS; G2 THEORY; GA-KR; POTENTIALS; EXTENSION; SPECTRUM AB The Gaussian-2 (G2) procedure, with spin-orbit coupling correction estimated by the Breit-Pauli approach, is applied to study the energetics of XO/XO+/XO- and XOH/XOH+ (X = F, Cl, Br, I). Accurate thermochemical data for these environmentally important species, in particular for the anions and iodine containing species, have not been accurately determined experimentally. For example, for IO the reported experimental heat of formation varies from 109 kJ mol(-1) to 177 kJ mol(-1). Using the G2 results it is now possible to recommend a set of self-consistent thermochemical data of heats of formation, ionization energies, electron affinities, proton affinities and bond dissociation energies for XO and related species. In general, among the disparate experimental data, the more recently reported heats of formation for FO-, BrO+, BrO-, BrOH, BrOH+, IO, IO+, IO-, IOH, IOH+ are found to be in good agreement with the G2 results. C1 IOWA STATE UNIV,US DOE,AMES LAB,AMES,IA 50011. IOWA STATE UNIV,DEPT CHEM,AMES,IA 50011. CHINESE UNIV HONG KONG,DEPT CHEM,SHATIN,NT,HONG KONG. RP Ma, NL (reprint author), HONG KONG POLYTECH UNIV,DEPT APPL BIOL & CHEM TECHNOL,HONG KONG,HONG KONG. NR 36 TC 11 Z9 11 U1 0 U2 2 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0026-8976 J9 MOL PHYS JI Mol. Phys. PD JUN 20 PY 1997 VL 91 IS 3 BP 495 EP 501 DI 10.1080/002689797171382 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA XF713 UT WOS:A1997XF71300012 ER PT J AU Raghavachari, K Stefanov, BB Curtiss, LA AF Raghavachari, K Stefanov, BB Curtiss, LA TI Accurate density functional thermochemistry for larger molecules SO MOLECULAR PHYSICS LA English DT Article ID SET MODEL CHEMISTRY; CORRELATION-ENERGY; GAUSSIAN-2 THEORY; ELECTRON-GAS; APPROXIMATION; EXCHANGE; 1ST-ROW AB Density functional methods are combined with isodesmic bond separation reaction energies to yield accurate thermochemistry for larger molecules. Seven different density functionals are assessed for the evaluation of heats of formation, Delta H-f(0) (298 K), for a test set of 40 molecules composed of H, C, O and N. The use of bond separation energies results in a dramatic improvement in the accuracy of all the density functionals. The B3-LYP functional has the smallest mean absolute deviation from experiment (1.5 kcal mol(-1)). C1 ARGONNE NATL LAB,DIV CHEM TECHNOL,DIV MAT SCI,ARGONNE,IL 60439. RP Raghavachari, K (reprint author), AT&T BELL LABS,LUCENT TECHNOL,MURRAY HILL,NJ 07974, USA. RI Stefanov, Boris/E-8905-2012 NR 32 TC 87 Z9 88 U1 1 U2 2 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0026-8976 J9 MOL PHYS JI Mol. Phys. PD JUN 20 PY 1997 VL 91 IS 3 BP 555 EP 559 DI 10.1080/002689797171445 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA XF713 UT WOS:A1997XF71300018 ER PT J AU Rohlfing, CM Cahill, PA AF Rohlfing, CM Cahill, PA TI A quantum chemical study of the isomers of bis(methano)fullerene, C-60(CH2)(2) SO MOLECULAR PHYSICS LA English DT Article ID C60H2; DERIVATIVES; C70H2 AB Building on past success using quantum chemical predictions of relative isomer stabilities in guiding the synthesis of the hydrofullerenes C60H2, C60H4 and C70H2, semiempirical and ab initio methods are used to examine the eight isomers of bis(methano)fullerene, C-60(CH2)(2). The calculated lowest energy structure has two -CH2- units bridging adjacent junctions between six-membered rings. Structural and energetic comparisons are made between the C-60(CH2)(2) isomers and the analogous forms of C60H4. From a thermodynamic point of view, it is predicted that reactions of C-60 that product C-60(CH2)(2) (and C-60(CR2)(2)) Will yield mixtures of isomers, and not a few discrete products as found for the hydrofullerenes. C1 SANDIA NATL LABS,ELECT & OPT MAT DEPT,ALBUQUERQUE,NM 87185. RP Rohlfing, CM (reprint author), SANDIA NATL LABS,COMBUST CHEM DEPT,MS 9055,LIVERMORE,CA 94551, USA. NR 22 TC 3 Z9 3 U1 0 U2 1 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0026-8976 J9 MOL PHYS JI Mol. Phys. PD JUN 20 PY 1997 VL 91 IS 3 BP 561 EP 565 DI 10.1080/002689797171454 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA XF713 UT WOS:A1997XF71300019 ER PT J AU Conrad, S Mullins, DR Xin, QS Zhu, XY AF Conrad, S Mullins, DR Xin, QS Zhu, XY TI Thermal and photochemical pathways of H2S on GaAs(100) SO SURFACE SCIENCE LA English DT Article DE chemisorption; gallium arsenide; hydrogen sulphide; low index single crystal surfaces; photochemistry; soft X-ray photoelectron spectroscopy; sulfur; surface photochemistry ID GAAS(001) SURFACE; HYDROGEN-SULFIDE; GAAS; ADSORPTION; PHOTOEMISSION; DECOMPOSITION; ORIENTATION; ENHANCEMENT; PASSIVATION; SULFUR AB The thermal and photo-induced dissociation of H2S on the Ga-rich GaAs(100) surface has been studied by synchrotron radiation soft X-ray photoelectron spectroscopy (SXPS), in conjunction with thermal desorption spectroscopy (TDS) and low-energy electron diffraction (LEED). H2S adsorbs in both molecular and dissociative forms at a surface temperature of 90 K, with a saturation coverage of 0.57 ML. The molecularly adsorbed H2S is unstable and desorbs/dissociates below 200 K; above 200 K, only SH and atomic S species are left on the surface. The dissociation of surface SH species is accompanied by the recombinative desorption of H2S and H-2. This process is completed by similar to 450 K, above which temperature surface sulfur atoms in two different chemical environments are observed. These sulfur atoms are attributed to Ga-S monomer and dimer surface species, respectively. The former is converted to the latter upon annealing al 700-750 K. The annealed and dimerized GaAs(100)/S surface shows a (2 x 1) LEED pattern in a broad sulfur coverage region. Both surface H2S and SH species dissociate readily upon UV laser or white light synchrotron radiation. At 193 nm, the initial photodissociation cross-sections for adsorbed H2S and SH species were estimated to be 6 x 10(-18) and 6 x 10(-19) cm(2), respectively. As a result of photodissociation, the amount of sulfur deposition can be significantly increased. At sulfur coverages above 0.5 ML, annealing at 750 K results in two distinctively different sulfur states, which are attributed to surface and subsurface S, respectively. (C) 1997 Elsevier Science B.V. C1 SO ILLINOIS UNIV,DEPT CHEM,CARBONDALE,IL 62901. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RI Schaff, William/B-5839-2009 NR 25 TC 9 Z9 9 U1 1 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD JUN 20 PY 1997 VL 382 IS 1-3 BP 79 EP 92 DI 10.1016/S0039-6028(97)00100-3 PG 14 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA XQ141 UT WOS:A1997XQ14100020 ER PT J AU Eriksson, O Trygg, J Hjortstam, O Johansson, B Wills, JM AF Eriksson, O Trygg, J Hjortstam, O Johansson, B Wills, JM TI Theoretical aspects of the 4f-localization at the surface of alpha-Ce SO SURFACE SCIENCE LA English DT Article DE density functional calculations; magnetic phenomena; surface electronic phenomena ID ELECTRONIC-STRUCTURE; GAMMA->ALPHA TRANSITION; ORBITAL POLARIZATION; GAMMA TRANSITION; PHASE TRANSITION; A-PU; CERIUM; DENSITY; SPECTROSCOPY; SYSTEMS AB Electronic structure calculations, based on density functional theory, demonstrate that the surface of alpha-Ce is spin and orbitally polarized and very similar to that obtained from a calculation for bulk gamma-Ce. In contrast, the lower lying layers do not deviate from characteristics associated with bulk alpha-Ce. These results imply that the surface of alpha-Ce is gamma-like. This is consistent with photoemission experiments and the calculations provide a theoretical complement to the these data. In addition to confirming the picture given by the photoemission data, we demonstrate that it is only the topmost layer of Ce atoms which have electronic properties which deviate from the bulk. This in turn shows that the chemical bonding of the surface atoms is very different compared to the bulk atoms. Our finding that it is only the topmost layer of alpha-Ce which deviates from bulk behaviour can probably be verified experimentally. (C) 1997 Elsevier Science B.V. C1 UNIV UPPSALA,DEPT PHYS,S-75121 UPPSALA,SWEDEN. LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87544. LOS ALAMOS NATL LAB,CTR MAT SCI,LOS ALAMOS,NM 87544. RI Eriksson, Olle/E-3265-2014 OI Eriksson, Olle/0000-0001-5111-1374 NR 34 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD JUN 20 PY 1997 VL 382 IS 1-3 BP 93 EP 99 DI 10.1016/S0039-6028(97)00101-5 PG 7 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA XQ141 UT WOS:A1997XQ14100021 ER PT J AU Cheng, LW Lyman, PF Sturchio, NC Bedzyk, MJ AF Cheng, LW Lyman, PF Sturchio, NC Bedzyk, MJ TI X-ray standing wave investigation of the surface structure of selenite anions adsorbed on calcite SO SURFACE SCIENCE LA English DT Letter DE adsorption; CaCO3; calcite; low-index single crystal surfaces; selenite; SeO3; surface structure; X-ray standing waves (XSW) ID HYDROUS FERRIC-OXIDE; MECHANISM; SORPTION AB The adsorption of selenite ions (SeO32-) From a dilute aqueous solution onto a freshly-cleaved calcite (10 (1) over bar 4 surface was studied with the X-ray standing wave (XSW) technique. The complex ion SeO32- is found to selectively adsorb at the CO32- site via ionic exchange, forming a two-dimensional solid-solution of the form Ca(SeO3)(x)(CO3)(1-x) at the interface. The calcite (10 (1) over bar 4), (0006) and (11 (2) over bar 0) Bragg reflections were used to triangulate the Se position with respect to the calcite lattice. The local surface structure al the SeO32- adsorbate site, derived From the XSW results, is consistent with a model in which the base of the SeO3(2-) trigonal pyramid aligns with (and replaces) the CO32- equilateral triangular group. The SeO32- adsorption saturated at a coverage of 0.02 monolayers. Under identical chemical conditions, selenate (SeO42-) adsorption was inhibited. (C) 1997 Elsevier Science B.V. C1 NORTHWESTERN UNIV,DEPT MAT SCI,EVANSTON,IL 60208. NORTHWESTERN UNIV,MAT RES CTR,EVANSTON,IL 60208. ARGONNE NATL LAB,DIV ENVIRONM RES,ARGONNE,IL 60439. ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. RI Bedzyk, Michael/B-7503-2009; Cheng, Likwan/C-1436-2013; Bedzyk, Michael/K-6903-2013 NR 23 TC 32 Z9 32 U1 2 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD JUN 20 PY 1997 VL 382 IS 1-3 BP L690 EP L695 DI 10.1016/S0039-6028(97)00167-2 PG 6 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA XQ141 UT WOS:A1997XQ14100008 ER PT J AU Dutta, NK Tayahi, M Choquette, KD AF Dutta, NK Tayahi, M Choquette, KD TI Transmission experiments using oxide confined vertical cavity surface emitting lasers SO ELECTRONICS LETTERS LA English DT Article DE vertical cavity surface emitting lasers; optical fibre communication AB The high speed modulation characteristics and performance in optical fibre transmission links of oxide confined vertical cavity surface emitting lasers are reported. The lasers have bandwidths of 13 GHz. Error-free transmission is obtained for both subcarrier modulated multichannel transmission and directly modulated digital transmission at 8 Gbit/s. C1 Univ Connecticut, Dept Phys, Storrs, CT 06269 USA. Univ Connecticut, Photon Res Ctr, Storrs, CT 06269 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Dutta, NK (reprint author), Univ Connecticut, Dept Phys, Storrs, CT 06269 USA. NR 6 TC 10 Z9 10 U1 0 U2 0 PU IEE-INST ELEC ENG PI HERTFORD PA MICHAEL FARADAY HOUSE SIX HILLS WAY STEVENAGE, HERTFORD SG1 2AY, ENGLAND SN 0013-5194 J9 ELECTRON LETT JI Electron. Lett. PD JUN 19 PY 1997 VL 33 IS 13 BP 1147 EP 1148 DI 10.1049/el:19970765 PG 2 WC Engineering, Electrical & Electronic SC Engineering GA YX447 UT WOS:000072040900032 ER PT J AU Bililign, S Liu, L Feigerle, CS Miller, JC AF Bililign, S Liu, L Feigerle, CS Miller, JC TI Metal ion chemistry in clusters initiated by ionization/dissociation of organometallic precursors SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID MULTI-PHOTON DISSOCIATION; GAS-PHASE; MULTIPHOTON IONIZATION; HOMOGENEOUS NUCLEATION; MOLECULAR CLUSTERS; IRON PENTACARBONYL; EXCITED-STATE; PHOTOCHEMISTRY; SPECTROSCOPY; DEPENDENCE AB A novel method is described for the initiation and observation of metal ion-molecule reactions in dusters. A heterocluster composed of organometallic molecules and reactant species is formed by coexpansion in a supersonic jet. Photoionization of the precursor molecules by a picosecond, 266 nm laser pulse efficiently strips away the ligands, leaving metal ions and metal cluster ions in close proximity to reactant molecules. Subsequent ion-molecule reactions take place which are followed by monitoring the products by time-of-flight mass spectrometry. Using iron pentacarbonyl as an example, the formation of metal ions and cluster ions is demonstrated, and their reaction with nitric oxide and nitrous oxide is described. C1 OAK RIDGE NATL LAB,CHEM & BIOL PHYS SECT,OAK RIDGE,TN 37831. UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996. N CAROLINA AGR & TECH STATE UNIV,DEPT PHYS,GREENSBORO,NC 27411. NR 48 TC 7 Z9 7 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD JUN 19 PY 1997 VL 101 IS 25 BP 4569 EP 4573 DI 10.1021/jp970476d PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA XF421 UT WOS:A1997XF42100014 ER PT J AU Micic, OI Cheong, HM Fu, H Zunger, A Sprague, JR Mascarenhas, A Nozik, AJ AF Micic, OI Cheong, HM Fu, H Zunger, A Sprague, JR Mascarenhas, A Nozik, AJ TI Size-dependent spectroscopy of InP quantum dots SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID ELECTRON; EXCITON; STATES; TRAPS; CDS AB The spectroscopic behavior of colloidal InP quantum dots (QDs) has been investigated as a function of the mean QD diameter (which ranged from 26 to 60 Angstrom). Absorption spectra show up to three peaks or shoulders which reflect excited state transitions in the QDs. Global photoluminescence (PL) spectra (excitation well to the blue of the absorption onset and which consequently excites most of the QDs in the size distribution) show broad PL emission. The emission and absorption features shift to higher energy with decreasing QD size. Resonant PL spectra (size-selective excitation into the tail of the absorption onset) show increasing fluorescence line narrowing with increasing excitation wavelength PL and photoluminescence excitation spectroscopy were used to derive the PL red shift as a function of QD size. The resonant red shifts for QDs of a single size were extracted from PL data that reflect the emission from an ensemble of QD diameters. An analysis of the single-dot resonant red shift (difference between PL peak and the first absorption peak) as a function of the single QD diameter indicate that the results are consistent with a model in which the emission occurs from an intrinsic, spin-forbidden state, split from its singlet counterpart, due to screened electron-hole exchange. RP Micic, OI (reprint author), NATL RENEWABLE ENERGY LAB,1617 COLE BLVD,GOLDEN,CO 80401, USA. RI Cheong, Hyeonsik/D-7424-2012; Zunger, Alex/A-6733-2013 OI Cheong, Hyeonsik/0000-0002-2347-4044; NR 32 TC 215 Z9 219 U1 7 U2 63 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD JUN 19 PY 1997 VL 101 IS 25 BP 4904 EP 4912 DI 10.1021/jp9704731 PG 9 WC Chemistry, Physical SC Chemistry GA XF418 UT WOS:A1997XF41800007 ER PT J AU Binetruy, P Irges, N Lavignac, S Ramond, P AF Binetruy, P Irges, N Lavignac, S Ramond, P TI Anomalous U(1) and low-energy physics: The power of D-flatness and holomorphy SO PHYSICS LETTERS B LA English DT Article ID MASS MATRIX MODELS; GAUGE SYMMETRIES; STRING THEORY; MU-PROBLEM; TERMS; SUPERGRAVITY; HIERARCHY AB In models with an anomalous abelian symmetry broken at a very large scale, we study which requirements to impose on the anomalous charges in order to prevent standard model fields from acquiring large vacuum expectation values. The use of holomorphic invariants to study D-flat directions for the anomalous symmetry, proves to be a very powerful tool. We find that in order to forbid unphysical configurations at that scale, the superpotential must contain many interaction terms, including the usual Yukawa terms. Our analysis suggests that the anomalous charge of the mu-term is zero. It is remarkable that, together with the seesaw mechanism, and mass hierarchies, this implies a natural conservation of R-parity. (C) 1997 Elsevier Science B.V. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DEPT PHYS,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,THEORET PHYS GRP,BERKELEY,CA 94720. UNIV FLORIDA,INST FUNDAMENTAL THEORY,DEPT PHYS,GAINESVILLE,FL 32611. RP Binetruy, P (reprint author), UNIV PARIS 11,PHYS THEOR & HAUTES ENERGIES LAB,BAT 210,F-91405 ORSAY,FRANCE. NR 38 TC 36 Z9 36 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD JUN 19 PY 1997 VL 403 IS 1-2 BP 38 EP 46 DI 10.1016/S0370-2693(97)00408-5 PG 9 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA XH295 UT WOS:A1997XH29500007 ER PT J AU Esumi, S Heinz, U Xu, N AF Esumi, S Heinz, U Xu, N TI Collective flow or random walk? SO PHYSICS LETTERS B LA English DT Article ID HEAVY-ION COLLISIONS; NUCLEUS-NUCLEUS COLLISIONS; SPECTRA AB Using recently measured transverse momentum spectra from 158 AGeV/c Pb+Pb and 200 AGeV/c S+S collisions at the CERN SPS, we address the question whether the transverse motion of hadrons produced in ultra-relativistic heavy-ion collisions is due to random walk initial state collisions or due to multi-scattering induced collective flow. (C) 1997 Published by Elsevier Science B.V. C1 UNIV REGENSBURG,INST THEORET PHYS,D-93040 REGENSBURG,GERMANY. LOS ALAMOS NATL LAB,P25,LOS ALAMOS,NM 87545. RP Esumi, S (reprint author), UNIV HEIDELBERG,INST PHYS,PHILOSOPHENWEG 12,D-69120 HEIDELBERG,GERMANY. NR 24 TC 6 Z9 6 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD JUN 19 PY 1997 VL 403 IS 1-2 BP 145 EP 148 DI 10.1016/S0370-2693(97)00509-1 PG 4 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA XH295 UT WOS:A1997XH29500024 ER PT J AU Acciarri, M Adriani, O AguilarBenitez, M Ahlen, S Alcaraz, J Alemanni, G Allaby, J Aloisio, A Alverson, G Alviggi, MG Ambrosi, G Anderhub, H Andreev, VP Angelescu, T Anselmo, F Arefiev, A Azemoon, T Aziz, T Bagnaia, P Baksay, L Banerjee, S Banicz, K Barczyk, A Barillere, R Barone, L Bartalini, P Baschirotto, A Basile, M Battiston, R Bay, A Becattini, F Becker, U Behner, F Berdugo, J Berges, P Bertucci, B Betev, BL Bhattacharya, S Biasini, M Biland, A Bilei, GM Blaising, JJ Blyth, SC Bobbink, GJ Bock, R Bohm, A Borgia, B Bourilkov, D Bourquin, M Braccini, S Branson, JG Brigljevic, V Brock, IC Buffini, A Buijs, A Burger, JD Burger, WJ Busenitz, J Button, A Cai, XD Campanelli, M Capell, M Romeo, GC Carlino, G Cartacci, AM Casaus, J Castellini, G Cavallari, F Cavallo, N Cecchi, C Cerrada, M Cesaroni, F Chamizo, M Chang, YH Chaturvedi, UK Chekanov, SV Chemarin, M Chen, A Chen, G Chen, GM Chen, HF Chen, HS Chereau, X Chiefari, G Chien, CY Cifarelli, L Cindolo, F Civinini, C Clare, I Clare, R Cohn, HO Coignet, G Colijn, AP Colino, N Commichau, V Costantini, S Cotorobai, F delaCruz, B Csilling, A Dai, TS DAlessandro, R deAsmundis, R Degre, A Deiters, K dellaVolpe, D Denes, P DeNotaristefani, F DiBitonto, D Diemoz, M vanDierendonck, D DiLodovico, F Dionisi, C Dittmar, M Dominguez, A Doria, A Dova, MT Duchesneau, D Duinker, P Duran, I Dutta, S Easo, S Efremenko, Y ElMamouni, H Engler, A Eppling, FJ Erne, FC Ernenwein, JP Extermann, P Fabre, M Faccini, R Falciano, S Favara, A Fay, J Fedin, O Felcini, M Fenyi, B Ferguson, T Ferroni, F Fesefeldt, H Fiandrini, E Field, JH Filthaut, F Fisher, PP Fisk, I Forconi, G Fredj, L Freudenreich, K Furetta, C Galaktionov, Y Ganguli, SN GarciaAbia, P Gau, SS Gentile, S Gheordanescu, N Giagu, S Goldfarb, S Goldstein, J Gong, ZE Gougas, A Gratta, G Gruenewald, MW Gupta, VK Gutay, LJ Hartmann, B Hasan, A Hatzifotiadou, D Hebbeker, T Herve, A vanHoek, WC Hofer, H Hong, SJ Hoorani, H Hou, SR Hu, G Innocente, V Jenkes, K Jin, BN Jones, LW deJong, P JosaMutuberria, I Kasser, A Khan, RA Kamrad, D Kamyshkov, Y Kapustinsky, JS Karyotakis, Y Kaur, M KienzleFocacci, MN Kim, D Kim, DH Kim, JK Kim, SC Kim, YG Kinnison, WW Kirkby, A Kirkby, D Kirkby, J Kiss, D Kittel, W Klimentov, A Konig, AC Korolko, I Koutsenko, V Kraemer, RW Krenz, W Kunin, A deGuevara, PL Laktineh, I Landi, G Lapoint, C LassilaPerini, K Laurikainen, P Lebeau, M Lebedev, A Lebrun, P Lecomte, P Lecoq, P LeCoultre, P LeGoff, JM Leiste, R Leonardi, E Levtchenko, P Li, C Lieb, E Lin, CH Lin, WT Linde, FL Lista, L Liu, ZA Lohmann, W Longo, E Lu, W Lu, YS Lubelsmeyer, K Luci, C Luckey, D Luminari, L Lustermann, W Ma, WG Maity, M Majumder, G Malgeri, L Malinin, A Mana, C Mangeol, D Mangla, S Marchesini, P Marin, A Martin, JP Marzano, F Massaro, GGG McNally, D McNeil, RR Mele, S Merola, L Meschini, M Metzger, WJ vonderMey, M Mi, Y Mihul, A vanMil, AJW Mirabelli, G Mnich, J Molnar, P Monteleoni, B Moore, R Morganti, S Moulik, T Mount, R Muller, S Muheim, F Muijs, AJM Nagy, E Nahn, S Napolitano, M NessiTedaldi, E Newman, H Niessen, T Nippe, A Nisati, A Nowak, H Oh, YD Opitz, H Organtini, G Ostonen, R Palomares, C Pandoulas, D Paoletti, S Paolucci, P Park, HK Park, IH Pascale, G Passaleva, G Patricelli, S Paul, T Pauluzzi, M Paus, C Pauss, F Peach, D Pei, YJ Pensotti, S PerretGallix, D Petersen, B Petrak, S Pevsner, A Piccolo, D Pieri, H Pinto, JC Piroue, PA Pistolesi, E Plyaskin, V Pohl, M Pojidaev, V Postema, H Produit, N Prokofiev, D RahalCallot, G Rancoita, PG Rattaggi, M Raven, G Razis, P Read, K Ren, D Rescigno, M Reucroft, S vanRhee, T Riemann, S Riles, K Robohm, A Rodin, J Roe, BP Romero, L RosierLees, S Rosselet, P vanRossum, W Roth, S Rubio, JA Ruschmeier, D Rykaczewski, H Salicio, J Sanchez, E Sanders, MP Sarakinos, ME Sarkar, S Sassowsky, M Schafer, C Schegelsky, V SchmidtKaerst, S Schmitz, D Schmitz, P Scholz, N Schopper, H Schotanus, DJ Schwenke, J Schwering, G Sciacca, C Sciarrino, D Servoli, L Shevchenko, S Shivarov, N Shoutko, V Shumilov, E Shvorob, A Siedenburg, T Son, D Sopczak, A Smith, B Spillantini, P Steuer, M Stickland, DP Stone, H Stoyanov, B Straessner, A Strauch, K Sudhakar, K Sultanov, G Sun, LZ Susinno, GF Suter, H Swain, JD Tang, XW Tauscher, L Taylor, L Ting, SCC Ting, SM Tonutti, M Tonwar, SC Toth, J Tully, C Tuchsherer, H Tung, KL Uchida, Y Ulbricht, J Uwer, U Valente, E VandeWalle, RT Vesztergombi, G Vetlitsky, I Viertel, G Vivargent, M Volkert, R Vogel, H Vogt, H Vorobiev, I Vorobyov, AA Vorvolakos, A Wadhwa, M Wallraff, W Wang, JC Wang, XL Wang, ZM Weber, A Wittgenstein, F Wu, SX Wynhoff, S Xu, J Xu, ZZ Yang, BZ Yang, CG Yao, XY Ye, JB Yeh, SC You, JM Zalite, A Zalite, Y Zemp, P Zeng, Y Zhang, Z Zhang, ZP Zhou, B Zhu, GY Zhu, RY Zichichi, A Ziegler, F AF Acciarri, M Adriani, O AguilarBenitez, M Ahlen, S Alcaraz, J Alemanni, G Allaby, J Aloisio, A Alverson, G Alviggi, MG Ambrosi, G Anderhub, H Andreev, VP Angelescu, T Anselmo, F Arefiev, A Azemoon, T Aziz, T Bagnaia, P Baksay, L Banerjee, S Banicz, K Barczyk, A Barillere, R Barone, L Bartalini, P Baschirotto, A Basile, M Battiston, R Bay, A Becattini, F Becker, U Behner, F Berdugo, J Berges, P Bertucci, B Betev, BL Bhattacharya, S Biasini, M Biland, A Bilei, GM Blaising, JJ Blyth, SC Bobbink, GJ Bock, R Bohm, A Borgia, B Bourilkov, D Bourquin, M Braccini, S Branson, JG Brigljevic, V Brock, IC Buffini, A Buijs, A Burger, JD Burger, WJ Busenitz, J Button, A Cai, XD Campanelli, M Capell, M Romeo, GC Carlino, G Cartacci, AM Casaus, J Castellini, G Cavallari, F Cavallo, N Cecchi, C Cerrada, M Cesaroni, F Chamizo, M Chang, YH Chaturvedi, UK Chekanov, SV Chemarin, M Chen, A Chen, G Chen, GM Chen, HF Chen, HS Chereau, X Chiefari, G Chien, CY Cifarelli, L Cindolo, F Civinini, C Clare, I Clare, R Cohn, HO Coignet, G Colijn, AP Colino, N Commichau, V Costantini, S Cotorobai, F delaCruz, B Csilling, A Dai, TS DAlessandro, R deAsmundis, R Degre, A Deiters, K dellaVolpe, D Denes, P DeNotaristefani, F DiBitonto, D Diemoz, M vanDierendonck, D DiLodovico, F Dionisi, C Dittmar, M Dominguez, A Doria, A Dova, MT Duchesneau, D Duinker, P Duran, I Dutta, S Easo, S Efremenko, Y ElMamouni, H Engler, A Eppling, FJ Erne, FC Ernenwein, JP Extermann, P Fabre, M Faccini, R Falciano, S Favara, A Fay, J Fedin, O Felcini, M Fenyi, B Ferguson, T Ferroni, F Fesefeldt, H Fiandrini, E Field, JH Filthaut, F Fisher, PP Fisk, I Forconi, G Fredj, L Freudenreich, K Furetta, C Galaktionov, Y Ganguli, SN GarciaAbia, P Gau, SS Gentile, S Gheordanescu, N Giagu, S Goldfarb, S Goldstein, J Gong, ZE Gougas, A Gratta, G Gruenewald, MW Gupta, VK Gutay, LJ Hartmann, B Hasan, A Hatzifotiadou, D Hebbeker, T Herve, A vanHoek, WC Hofer, H Hong, SJ Hoorani, H Hou, SR Hu, G Innocente, V Jenkes, K Jin, BN Jones, LW deJong, P JosaMutuberria, I Kasser, A Khan, RA Kamrad, D Kamyshkov, Y Kapustinsky, JS Karyotakis, Y Kaur, M KienzleFocacci, MN Kim, D Kim, DH Kim, JK Kim, SC Kim, YG Kinnison, WW Kirkby, A Kirkby, D Kirkby, J Kiss, D Kittel, W Klimentov, A Konig, AC Korolko, I Koutsenko, V Kraemer, RW Krenz, W Kunin, A deGuevara, PL Laktineh, I Landi, G Lapoint, C LassilaPerini, K Laurikainen, P Lebeau, M Lebedev, A Lebrun, P Lecomte, P Lecoq, P LeCoultre, P LeGoff, JM Leiste, R Leonardi, E Levtchenko, P Li, C Lieb, E Lin, CH Lin, WT Linde, FL Lista, L Liu, ZA Lohmann, W Longo, E Lu, W Lu, YS Lubelsmeyer, K Luci, C Luckey, D Luminari, L Lustermann, W Ma, WG Maity, M Majumder, G Malgeri, L Malinin, A Mana, C Mangeol, D Mangla, S Marchesini, P Marin, A Martin, JP Marzano, F Massaro, GGG McNally, D McNeil, RR Mele, S Merola, L Meschini, M Metzger, WJ vonderMey, M Mi, Y Mihul, A vanMil, AJW Mirabelli, G Mnich, J Molnar, P Monteleoni, B Moore, R Morganti, S Moulik, T Mount, R Muller, S Muheim, F Muijs, AJM Nagy, E Nahn, S Napolitano, M NessiTedaldi, E Newman, H Niessen, T Nippe, A Nisati, A Nowak, H Oh, YD Opitz, H Organtini, G Ostonen, R Palomares, C Pandoulas, D Paoletti, S Paolucci, P Park, HK Park, IH Pascale, G Passaleva, G Patricelli, S Paul, T Pauluzzi, M Paus, C Pauss, F Peach, D Pei, YJ Pensotti, S PerretGallix, D Petersen, B Petrak, S Pevsner, A Piccolo, D Pieri, H Pinto, JC Piroue, PA Pistolesi, E Plyaskin, V Pohl, M Pojidaev, V Postema, H Produit, N Prokofiev, D RahalCallot, G Rancoita, PG Rattaggi, M Raven, G Razis, P Read, K Ren, D Rescigno, M Reucroft, S vanRhee, T Riemann, S Riles, K Robohm, A Rodin, J Roe, BP Romero, L RosierLees, S Rosselet, P vanRossum, W Roth, S Rubio, JA Ruschmeier, D Rykaczewski, H Salicio, J Sanchez, E Sanders, MP Sarakinos, ME Sarkar, S Sassowsky, M Schafer, C Schegelsky, V SchmidtKaerst, S Schmitz, D Schmitz, P Scholz, N Schopper, H Schotanus, DJ Schwenke, J Schwering, G Sciacca, C Sciarrino, D Servoli, L Shevchenko, S Shivarov, N Shoutko, V Shumilov, E Shvorob, A Siedenburg, T Son, D Sopczak, A Smith, B Spillantini, P Steuer, M Stickland, DP Stone, H Stoyanov, B Straessner, A Strauch, K Sudhakar, K Sultanov, G Sun, LZ Susinno, GF Suter, H Swain, JD Tang, XW Tauscher, L Taylor, L Ting, SCC Ting, SM Tonutti, M Tonwar, SC Toth, J Tully, C Tuchsherer, H Tung, KL Uchida, Y Ulbricht, J Uwer, U Valente, E VandeWalle, RT Vesztergombi, G Vetlitsky, I Viertel, G Vivargent, M Volkert, R Vogel, H Vogt, H Vorobiev, I Vorobyov, AA Vorvolakos, A Wadhwa, M Wallraff, W Wang, JC Wang, XL Wang, ZM Weber, A Wittgenstein, F Wu, SX Wynhoff, S Xu, J Xu, ZZ Yang, BZ Yang, CG Yao, XY Ye, JB Yeh, SC You, JM Zalite, A Zalite, Y Zemp, P Zeng, Y Zhang, Z Zhang, ZP Zhou, B Zhu, GY Zhu, RY Zichichi, A Ziegler, F TI Production of single W bosons at LEP SO PHYSICS LETTERS B LA English DT Article ID PAIR PRODUCTION; ROOT-S=1.8 TEV; P(P)OVER-BAR COLLISIONS; BHABHA SCATTERING; CROSS-SECTIONS; E+E COLLISIONS; COUPLINGS; DETECTOR; CONSTRUCTION; ASYMMETRIES AB We report on the observation of single W boson production in a data sample collected by the L3 detector at LEP2. The signal consists of large missing energy final states with a single energetic lepton or two hadronic jets. The cross-section is measured to be 0.61(-0.33)(+0.43) +/- 0.05 pb at the centre of mass energy root s = 172 GeV, consistent with the Standard Model expectation. From this measurement the following limits on the anomalous gamma WW gauge couplings are derived at 95% CL: -3.6 < Delta kappa gamma < 1.5 and -3.6 < lambda gamma < 3.6. (C) 1997 Published by Elsevier Science B.V. C1 RHEIN WESTFAL TH AACHEN, INST PHYS 3, D-52056 AACHEN, GERMANY. NIKHEF H, NATL INST HIGH ENERGY PHYS, NL-1009 DB AMSTERDAM, NETHERLANDS. UNIV AMSTERDAM, NL-1009 DB AMSTERDAM, NETHERLANDS. UNIV MICHIGAN, ANN ARBOR, MI 48109 USA. LAB ANNECY LE VIEUX PHYS PARTICULES, LAPP, IN2P3, CNRS, F-74941 ANNECY LE VIEUX, FRANCE. JOHNS HOPKINS UNIV, BALTIMORE, MD 21218 USA. UNIV BASEL, INST PHYS, CH-4056 BASEL, SWITZERLAND. LOUISIANA STATE UNIV, BATON ROUGE, LA 70803 USA. INST HIGH ENERGY PHYS, BEIJING 100039, PEOPLES R CHINA. HUMBOLDT UNIV BERLIN, D-10099 BERLIN, GERMANY. UNIV BOLOGNA, I-40126 BOLOGNA, ITALY. IST NAZL FIS NUCL, SEZIONE BOLOGNA, I-40126 BOLOGNA, ITALY. TATA INST FUNDAMENTAL RES, BOMBAY 400005, MAHARASHTRA, INDIA. BOSTON UNIV, BOSTON, MA 02215 USA. NORTHEASTERN UNIV, BOSTON, MA 02115 USA. INST ATOM PHYS, R-76900 BUCHAREST, ROMANIA. UNIV BUCHAREST, R-76900 BUCHAREST, ROMANIA. HUNGARIAN ACAD SCI, CENT RES INST PHYS, H-1525 BUDAPEST 114, HUNGARY. HARVARD UNIV, CAMBRIDGE, MA 02139 USA. MIT, CAMBRIDGE, MA 02139 USA. IST NAZL FIS NUCL, SEZIONE FIRENZE, I-50125 FLORENCE, ITALY. UNIV FLORENCE, I-50125 FLORENCE, ITALY. CERN, EUROPEAN LAB PARTICLE PHYS, CH-1211 GENEVA 23, SWITZERLAND. WORLD LAB, FBLJA PROJECT, CH-1211 GENEVA 23, SWITZERLAND. UNIV GENEVA, CH-1211 GENEVA 4, SWITZERLAND. SEFT, RES INST HIGH ENERGY PHYS, SF-00014 HELSINKI, FINLAND. UNIV LAUSANNE, CH-1015 LAUSANNE, SWITZERLAND. IST NAZL FIS NUCL, SEZIONE LECCE, I-73100 LECCE, ITALY. UNIV LECCE, I-73100 LECCE, ITALY. LOS ALAMOS NATL LAB, LOS ALAMOS, NM 87544 USA. UNIV LYON 1, INST NUCL PHYS, IN2P3, CNRS, F-69622 VILLEURBANNE, FRANCE. IST NAZL FIS NUCL, SEZIONE MILANO, I-20133 MILAN, ITALY. INST THEORET & EXPT PHYS, MOSCOW 117259, RUSSIA. IST NAZL FIS NUCL, SEZIONE NAPOLI, I-80125 NAPLES, ITALY. UNIV NAPLES, I-80125 NAPLES, ITALY. UNIV CYPRUS, DEPT NAT SCI, NICOSIA, CYPRUS. UNIV NIJMEGEN, NL-6525 ED NIJMEGEN, NETHERLANDS. NATL INST NUCL PHYS & HIGH ENERGY PHYS, NL-6525 ED NIJMEGEN, NETHERLANDS. OAK RIDGE NATL LAB, OAK RIDGE, TN 37831 USA. CALTECH, PASADENA, CA 91125 USA. IST NAZL FIS NUCL, SEZIONE PERUGIA, I-06100 PERUGIA, ITALY. UNIV PERUGIA, I-06100 PERUGIA, ITALY. CARNEGIE MELLON UNIV, PITTSBURGH, PA 15213 USA. PRINCETON UNIV, PRINCETON, NJ 08544 USA. IST NAZL FIS NUCL, SEZIONE ROMA, I-00185 ROME, ITALY. UNIV ROMA LA SAPIENZA, I-00185 ROME, ITALY. RUSSIAN ACAD SCI, INST NUCL PHYS, ST PETERSBURG, RUSSIA. UNIV SALERNO, I-84100 SALERNO, ITALY. IST NAZL FIS NUCL, I-84100 SALERNO, ITALY. UNIV CALIF SAN DIEGO, SAN DIEGO, CA 92093 USA. UNIV SANTIAGO, DEPT FIS PARTICULAS ELEMENTALES, E-15706 SANTIAGO DE COMPOSTELA, SPAIN. BULGARIAN ACAD SCI, CENT LAB MECHATRON & INSTRUMENTAT, BU-1113 SOFIA, BULGARIA. KOREA ADV INST SCI & TECHNOL, CTR HIGH ENERGY PHYS, TAEJON 305701, SOUTH KOREA. UNIV ALABAMA, TUSCALOOSA, AL 35486 USA. UNIV UTRECHT, NL-3584 CB UTRECHT, NETHERLANDS. NIKHEF H, NL-3584 CB UTRECHT, NETHERLANDS. PURDUE UNIV, W LAFAYETTE, IN 47907 USA. PAUL SCHERRER INST, CH-5232 VILLIGEN, SWITZERLAND. DESY, INST HOCHENERGIEPHYS, D-15738 ZEUTHEN, GERMANY. ETH ZURICH, CH-8093 ZURICH, SWITZERLAND. UNIV HAMBURG, D-22761 HAMBURG, GERMANY. HIGH ENERGY PHYS GRP, TAIPEI, TAIWAN. UNIV SCI & TECHNOL CHINA, HEFEI 230009, ANHUI, PEOPLES R CHINA. CIEMAT, E-28040 MADRID, SPAIN. RP Acciarri, M (reprint author), RHEIN WESTFAL TH AACHEN, INST PHYS 1, D-52056 AACHEN, GERMANY. RI Berdugo, Javier/A-2858-2015; Fiandrini, Emanuele/C-4549-2008; D'Alessandro, Raffaello/F-5897-2015; Lista, Luca/C-5719-2008; Kirkby, Jasper/A-4973-2012; Servoli, Leonello/E-6766-2012; bertucci, bruna/J-5237-2012; Cavallo, Nicola/F-8913-2012; Cerrada, Marcos/J-6934-2014; de la Cruz, Begona/K-7552-2014; Josa, Isabel/K-5184-2014; Vogel, Helmut/N-8882-2014; Ferguson, Thomas/O-3444-2014; Sanchez, Eusebio/H-5228-2015; Duran, Ignacio/H-7254-2015; Rancoita, Pier Giorgio/J-9896-2015; Hoorani, Hafeez/D-1791-2013; Palomares, Carmen/H-7783-2015; Fedin, Oleg/H-6753-2016; Roth, Stefan/J-2757-2016; Kamyshkov, Yuri/J-7999-2016; Di Lodovico, Francesca/L-9109-2016; OI Berdugo, Javier/0000-0002-7911-8532; D'Alessandro, Raffaello/0000-0001-7997-0306; Kirkby, Jasper/0000-0003-2341-9069; Servoli, Leonello/0000-0003-1725-9185; Cerrada, Marcos/0000-0003-0112-1691; Vogel, Helmut/0000-0002-6109-3023; Ferguson, Thomas/0000-0001-5822-3731; Sanchez, Eusebio/0000-0002-9646-8198; Rancoita, Pier Giorgio/0000-0002-1990-4283; Palomares, Carmen/0000-0003-4374-9065; Roth, Stefan/0000-0003-3616-2223; Kamyshkov, Yuri/0000-0002-3789-7152; Di Lodovico, Francesca/0000-0003-3952-2175; Longo, Egidio/0000-0001-6238-6787; Ambrosi, Giovanni/0000-0001-6977-9559; Castellini, Guido/0000-0002-0177-0643; Read, Kenneth/0000-0002-3358-7667; Diemoz, Marcella/0000-0002-3810-8530; Doria, Alessandra/0000-0002-5381-2649; Sciacca, Crisostomo/0000-0002-8412-4072; Faccini, Riccardo/0000-0003-2613-5141; Della Volpe, Domenico/0000-0001-8530-7447; Bertucci, Bruna/0000-0001-7584-293X; Filthaut, Frank/0000-0003-3338-2247; Goldstein, Joel/0000-0003-1591-6014 NR 45 TC 27 Z9 27 U1 2 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 EI 1873-2445 J9 PHYS LETT B JI Phys. Lett. B PD JUN 19 PY 1997 VL 403 IS 1-2 BP 168 EP 176 DI 10.1016/S0370-2693(97)00527-3 PG 9 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA XH295 UT WOS:A1997XH29500028 ER PT J AU Aitala, EM Amato, S Anjos, JC Appel, JA Ashery, D Banerjee, S Bediaga, I Blaylock, G Bracker, SB Burchat, PR Burnstein, RA Carter, T Carvalho, HS Copty, NK Costa, I Cremaldi, LM Darling, C Denisenko, K Fernandez, A Gagnon, P Gerzon, S Gounder, K Halling, AM Herrera, G Hurvits, G James, C Kasper, PA Kwan, S Langs, DC Leslie, J Lundberg, B MayTalBeck, S Meadows, BT Neto, JRTD Milburn, RH deMiranda, JM Napier, A Nguyen, A dOliveira, AB OShaughnessy, K Peng, KC Perera, LP Purohit, MV Quinn, B Radeztsky, S Rafatian, A Reay, MW Reidy, JJ dosReis, AC Rubin, HA Santha, AKS Santoro, AFS Schwartz, AJ Sheaff, M Sidwell, RA Slaughter, AJ Sokoloff, MD Stanton, NR Stenson, K Summers, DJ Takach, S Thorne, K Tripathi, AK Watanabe, S WeissBabai, R Wiener, J Witchey, N Wolin, E Yi, D Yoshida, S Zaliznyak, R Zhang, C AF Aitala, EM Amato, S Anjos, JC Appel, JA Ashery, D Banerjee, S Bediaga, I Blaylock, G Bracker, SB Burchat, PR Burnstein, RA Carter, T Carvalho, HS Copty, NK Costa, I Cremaldi, LM Darling, C Denisenko, K Fernandez, A Gagnon, P Gerzon, S Gounder, K Halling, AM Herrera, G Hurvits, G James, C Kasper, PA Kwan, S Langs, DC Leslie, J Lundberg, B MayTalBeck, S Meadows, BT Neto, JRTD Milburn, RH deMiranda, JM Napier, A Nguyen, A dOliveira, AB OShaughnessy, K Peng, KC Perera, LP Purohit, MV Quinn, B Radeztsky, S Rafatian, A Reay, MW Reidy, JJ dosReis, AC Rubin, HA Santha, AKS Santoro, AFS Schwartz, AJ Sheaff, M Sidwell, RA Slaughter, AJ Sokoloff, MD Stanton, NR Stenson, K Summers, DJ Takach, S Thorne, K Tripathi, AK Watanabe, S WeissBabai, R Wiener, J Witchey, N Wolin, E Yi, D Yoshida, S Zaliznyak, R Zhang, C TI Observation of D-pi production correlations in 500 GeV pi(-)-N interactions SO PHYSICS LETTERS B LA English DT Article ID PHYSICS AB We study the charge correlations between charm mesons produced in 500 GeV pi(-) -N interactions and the charged pions produced closest to them in phase space. With 110,000 fully reconstructed D mesons from experiment E791 at Fermilab, the correlations are studied as functions of the D pi - D mass difference and of Feynman x. We observe significant correlations which appear to originate from a combination of sources including fragmentation dynamics, resonant decays, and charge of the beam. (C) 1997 Published by Elsevier Science B.V. C1 CTR BRASILEIRO PESQUISAS FIS,RIO JANEIRO,BRAZIL. UNIV CALIF SANTA CRUZ,SANTA CRUZ,CA 95064. UNIV CINCINNATI,CINCINNATI,OH 45221. CINVESTAV IPN,MEXICO CITY 14000,DF,MEXICO. IIT,CHICAGO,IL 60616. KANSAS STATE UNIV,MANHATTAN,KS 66506. OHIO STATE UNIV,COLUMBUS,OH 43210. PRINCETON UNIV,PRINCETON,NJ 08544. UNIV AUTONOMA PUEBLA,MEXICO CITY,DF,MEXICO. UNIV S CAROLINA,COLUMBIA,SC 29208. STANFORD UNIV,STANFORD,CA 94305. TEL AVIV UNIV,TEL AVIV,ISRAEL. TUFTS UNIV,MEDFORD,MA 02155. UNIV WISCONSIN,MADISON,WI 53706. YALE UNIV,NEW HAVEN,CT 06511. FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. RP Aitala, EM (reprint author), UNIV MISSISSIPPI,UNIVERSITY,MS 38677, USA. RI Anjos, Joao/C-8335-2013; Santoro, Alberto/E-7932-2014; de Mello Neto, Joao/C-5822-2013 OI de Mello Neto, Joao/0000-0002-3234-6634 NR 9 TC 11 Z9 11 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD JUN 19 PY 1997 VL 403 IS 1-2 BP 185 EP 190 DI 10.1016/S0370-2693(97)00492-9 PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA XH295 UT WOS:A1997XH29500030 ER PT J AU Hampton, PD Daitch, CE Alam, TM Pruss, EA AF Hampton, PD Daitch, CE Alam, TM Pruss, EA TI Linear chain formation by an oxovanadium(V) complex of p-methylhexahomotrioxacalix[3]arene SO INORGANIC CHEMISTRY LA English DT Article ID MOLYBDENUM-NITRIDE-TRICHLORIDE; CRYSTAL-STRUCTURE; TRIPLE BONDS; V-51 NMR; MOLECULAR-STRUCTURES; IR-SPECTRUM; SOLID-STATE; POLYMERS; METALLOMACROCYCLES; PHTHALOCYANINES AB The oxovanadium(V) complex 4 can be readily synthesized by the reaction of the lithium salt of p-methylhexahomotrioxacalix[3]arene trianion 3 with VOCl3. Infrared spectra indicate a terminal V=O for complex 4 in solution and V=O ... V dative interactions in the solid state consistent with the formation of a mu-oxo-bridged linear chain polymer 1 (M = V, Y = O, X-3 = trianion of macrocycle 2a). Vanadium-51 NMR spectra indicate increased shielding for the linear chain polymer in the solid state compared to complex 4 in solution. Complex 4 and its linear chain polymer are proposed to have the oxovanadium group contained within the cup of the macrocycle ligand as shown in structures 5 and 7, respectively, where the cone represents macrocycle 2a. C1 UNIV NEW MEXICO,CTR MICROENGINEERED CERAM,ALBUQUERQUE,NM 87131. SANDIA NATL LABS,BULK PROPERTIES DEPT,ALBUQUERQUE,NM 87185. RP Hampton, PD (reprint author), UNIV NEW MEXICO,DEPT CHEM,ALBUQUERQUE,NM 87131, USA. NR 59 TC 25 Z9 25 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD JUN 18 PY 1997 VL 36 IS 13 BP 2879 EP 2883 DI 10.1021/ic9611195 PG 5 WC Chemistry, Inorganic & Nuclear SC Chemistry GA XF309 UT WOS:A1997XF30900030 ER PT J AU Cook, AR Curtiss, LA Miller, JR AF Cook, AR Curtiss, LA Miller, JR TI Fluorescence of the 1,4-benzoquinone radical anion SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID PHOTOINDUCED ELECTRON-TRANSFER; PORPHYRIN QUINONE CYCLOPHANES; PHOTOSYNTHETIC MODEL SYSTEMS; REACTION CENTER PROTEIN; FREE-ENERGY; RHODOPSEUDOMONAS-SPHAEROIDES; BACTERIAL PHOTOSYNTHESIS; CHARGE SEPARATION; NONPOLAR LIQUIDS; TRANSFER RATES AB Information about excited states of radical ions can enable their use as powerful oxidizing and reducing agents capable of driving chemical reactions. This article presents the first measurements of fluorescence from an excited state of the radical anion of 1,4-benzoquinone (BQ(-)), and the first report of a fluorescence quantum yield from any radical anion. BQ(-) was observed in both a 77 K 2-methyltetrahydrofuran matrix and a room temperature isooctane solution. The low fluorescence quantum yield, phi(f) = 0.003, and the presence of a 0.5 eV red shift of the emission band edge (593 nm) from the absorption band edge (475 nm) imply that the lowest energy transition in BQ(-), which is the source of the weak fluorescence, is formally forbidden. This conclusion is supported by both semiempirical and ab initio molecular orbital calculations. In addition, we determined the excited state lifetime of BQ(-) at 77 K to be 63 ns, with an excited state absorption spectrum peaking at 415 nm. RP ARGONNE NATL LAB, DIV CHEM, 9700 S CASS AVE, ARGONNE, IL 60439 USA. OI Cook, Andrew/0000-0001-6633-3447 NR 66 TC 37 Z9 37 U1 1 U2 16 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD JUN 18 PY 1997 VL 119 IS 24 BP 5729 EP 5734 DI 10.1021/ja970270q PG 6 WC Chemistry, Multidisciplinary SC Chemistry GA XF139 UT WOS:A1997XF13900029 ER PT J AU Kurtz, SR Allerman, AA Biefeld, RM AF Kurtz, SR Allerman, AA Biefeld, RM TI Midinfrared lasers and light-emitting diodes with InAsSb/InAsP strained-layer superlattice active regions SO APPLIED PHYSICS LETTERS LA English DT Article ID CONTINUOUS-WAVE OPERATION; MU-M AB The properties of InAsSb/InAsP strained-layer superlattice (SLS), midwave infrared materials, and devices are reported. SLSs were grown by metal-organic chemical vapor deposition and characterized by magnetophotoluminescence and x-ray diffraction. Excellent performance was observed for an SLS light emitting diode (LED) and an optically pumped SLS laser. The semimetal injected, broadband LED emitted at 4 mu m with 80 mu W of power at 300 K and 200 mA average current. The laser displayed 3.86 mu m emission at 240 K, the maximum operating temperature of the laser, and a characteristic temperature of 33 K. (C) 1997 American Institute of Physics. RP Kurtz, SR (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 16 TC 31 Z9 31 U1 1 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 JUN 16 PY 1997 VL 70 IS 24 BP 3188 EP 3190 DI 10.1063/1.119154 PG 3 WC Physics, Applied SC Physics GA XE543 UT WOS:A1997XE54300002 ER PT J AU Fischer, A Feng, Z Bykov, E ContrerasPuente, G Compaan, A CastilloAlvarado, FD Avendano, J Mason, A AF Fischer, A Feng, Z Bykov, E ContrerasPuente, G Compaan, A CastilloAlvarado, FD Avendano, J Mason, A TI Optical phonons in laser-deposited CdSxTe1-x films SO APPLIED PHYSICS LETTERS LA English DT Article ID RAMAN-SCATTERING; SEMICONDUCTORS; SYSTEM; ALLOYS; MODEL AB We report the longitudinal optical (LO) phonon frequencies for thin films of the ternary alloy CdSxTe1-x and their composition dependence for the full range of x values from pure CdTe to pure CdS. Pulsed laser deposition was used to prepare the polycrystalline thin films including compositions well inside the miscibility gap. We find that this ternary system exhibits a ''two-mode'' behavior with CdS- and CdTe-like longitudinal optic phonon modes. The modified random-element isodisplacement model yields a good description of the composition dependence of the LO phonon frequencies. (C) 1997 American Institute of Physics. C1 IPN,ESFM,MEXICO CITY 07738,DF,MEXICO. NREL,GOLDEN,CO 80401. RP Fischer, A (reprint author), UNIV TOLEDO,2801 W BANCROFT ST,TOLEDO,OH 43606, USA. NR 23 TC 19 Z9 20 U1 0 U2 5 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 JUN 16 PY 1997 VL 70 IS 24 BP 3239 EP 3241 DI 10.1063/1.119136 PG 3 WC Physics, Applied SC Physics GA XE543 UT WOS:A1997XE54300019 ER PT J AU Eaglesham, DJ Haynes, TE Gossmann, HJ Jacobson, DC Stolk, PA Poate, JM AF Eaglesham, DJ Haynes, TE Gossmann, HJ Jacobson, DC Stolk, PA Poate, JM TI Transient enhanced diffusion of Sb and B due to MeV silicon implants SO APPLIED PHYSICS LETTERS LA English DT Article ID POINT-DEFECTS; SI AB We measure the transient enhanced diffusion of shallow molecular-beam-epitaxy grown marker layers of Sb and B due to deep MeV Si+ ion implants at very high doses (approximate to 10(16) cm(-2)). We expect the near-surface region of these implants to be vacancy rich, and we observe transient enhanced diffusion of Sb (the classic vacancy diffuser). The large enhancements imply a significant vacancy supersaturation (approximate to 700 at 740 degrees C). Double implantation of the high-dose MeV Si followed by a shallow (40 keV) Si implant and annealing produces a greatly reduced number of {311} defects compared to a 40 keV implant into virgin Si, again consistent with a vacancy-rich region in the near-surface region of an MeV implant. However the shallow B marker layers also show transient enhanced diffusion for the same MeV implant under similar annealing conditions, implying that an interstitial supersaturation is present at the same time. We discuss possible mechanisms for a simultaneous supersaturation of both types of point defects. (C) 1997 American Institute of Physics. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP Eaglesham, DJ (reprint author), LUCENT TECHNOL,BELL LABS,MURRAY HILL,NJ 07974, USA. RI Haynes, Tony/P-8932-2015 OI Haynes, Tony/0000-0003-2871-4745 NR 12 TC 44 Z9 44 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 JUN 16 PY 1997 VL 70 IS 24 BP 3281 EP 3283 DI 10.1063/1.119150 PG 3 WC Physics, Applied SC Physics GA XE543 UT WOS:A1997XE54300033 ER PT J AU Findikoglu, AT Arendt, PN Foltyn, SR Groves, JR Jia, QX Peterson, EJ Bulaevskii, L Maley, MP Reagor, DW AF Findikoglu, AT Arendt, PN Foltyn, SR Groves, JR Jia, QX Peterson, EJ Bulaevskii, L Maley, MP Reagor, DW TI Power-dependent microwave properties of superconducting YBa2Cu3O7-x films on buffered polycrystalline substrates SO APPLIED PHYSICS LETTERS LA English DT Article ID YTTRIA-STABILIZED-ZIRCONIA; THIN-FILMS; SAPPHIRE; LAYERS AB We have studied the microwave properties of 0.4 mu m thick YBa2Cu3O7-x (YBCO) films on polycrystalline substrates with ion-beam-assisted-deposited yttria-stabilized zirconia buffer layers using a parallel-plate resonator technique at 10 GHz. The YBCO films with similar in-plane texture grown on both forsterite and Ni-based alloy substrates show similar microwave properties. We measure low-power surface resistance R-s values of about 0.5 m Omega at 76 K and 0.15 m Omega at 4 K for films with an in-plane mosaic spread of about 7 degrees. Single-tone power-dependence measurements show that the surface resistance and the surface reactance increase linearly and by the same amount with increasing microwave field level. At intermediate power levels, the intermodulation measurements show odd-order intermodulation products that increase quadratically with two-tone input power. These results indicate a hysteretic vortex penetration mechanism in the weak links as the most plausible source of the observed nonlinearities in these films. (C) 1997 American Institute of Physics. RP Findikoglu, AT (reprint author), LOS ALAMOS NATL LAB,DIV MAT SCI & TECHNOL,LOS ALAMOS,NM 87545, USA. RI Jia, Q. X./C-5194-2008 NR 21 TC 15 Z9 15 U1 2 U2 4 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 JUN 16 PY 1997 VL 70 IS 24 BP 3293 EP 3295 DI 10.1063/1.118431 PG 3 WC Physics, Applied SC Physics GA XE543 UT WOS:A1997XE54300037 ER PT J AU Pecharsky, VK Gschneidner, KA AF Pecharsky, VK Gschneidner, KA TI Tunable magnetic regenerator alloys with a giant magnetocaloric effect for magnetic refrigeration from similar to 20 to similar to 290 K SO APPLIED PHYSICS LETTERS LA English DT Article ID GADOLINIUM AB A giant magnetocaloric effect (Delta S-mag) has been discovered in the GD(5)(SixGe1-x)(4) pseudobinary alloys, where x less than or equal to 0.5. For the temperature range between similar to 50 and similar to 280 K it exceeds the reversible (with respect to alternating magnetic field) Delta S-mag for any known magnetic refrigerant material at the corresponding Curie temperature by a factor of 2-10. The two most striking features of this alloy system are: (1) the first order phase transformation, which brings about the large Delta S-mag in Gd-5(SixGe1-x)4, is reversible with respect to alternating magnetic field, i.e., the giant magnetocaloric effect can be utilized in an active magnetic regenerator magnetic refrigerator; and (2) the ordering temperature is tunable from similar to 30 to similar to 276 K by adjusting the Si:Ge ratio without losing the giant magnetic entropy change. (C) 1997 American Institute of Physics. C1 IOWA STATE UNIV,DEPT MAT SCI & ENGN,AMES,IA 50011. RP Pecharsky, VK (reprint author), IOWA STATE UNIV,AMES LAB,AMES,IA 50011, USA. NR 9 TC 554 Z9 593 U1 11 U2 72 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 JUN 16 PY 1997 VL 70 IS 24 BP 3299 EP 3301 DI 10.1063/1.119206 PG 3 WC Physics, Applied SC Physics GA XE543 UT WOS:A1997XE54300039 ER PT J AU Wang, QH Corrigan, TD Dai, JY Chang, RPH Krauss, AR AF Wang, QH Corrigan, TD Dai, JY Chang, RPH Krauss, AR TI Field emission from nanotube bundle emitters at low fields SO APPLIED PHYSICS LETTERS LA English DT Article ID CARBON AB The fabrication of nanotube field emitters with an onset field as low as 0.8 V/mu m is described and the low-field electron emission mechanism is discussed. These emitters are made using nanotube cathode deposit with the addition of epoxy resin. The preferred orientation of nanotubes in nanotube bundles of the deposit is preserved. The nanotube tips are sharpened by exposing the nanotube bundle surface to a microwave oxygen plasma. The local-field enhancement factor is estimated to be 8000 by using the Fowler-Nordheim equation. The low onset field is attributed to the well-distributed, highly orientated sharp tips at the sample surface. (C) 1997 American Institute of Physics. C1 ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. RP Wang, QH (reprint author), NORTHWESTERN UNIV,DEPT MAT SCI & ENGN,EVANSTON,IL 60208, USA. RI Chang, R.P.H/B-7505-2009; Dai, Jiyan/I-7098-2013 OI Dai, Jiyan/0000-0002-7720-8032 NR 8 TC 385 Z9 419 U1 2 U2 36 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 JUN 16 PY 1997 VL 70 IS 24 BP 3308 EP 3310 DI 10.1063/1.119146 PG 3 WC Physics, Applied SC Physics GA XE543 UT WOS:A1997XE54300042 ER PT J AU Erickson, MD AF Erickson, MD TI Future instrumentation SO CHEMICAL & ENGINEERING NEWS LA English DT Letter RP Erickson, MD (reprint author), US DOE,NEW YORK,NY 10014, USA. 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 0009-2347 J9 CHEM ENG NEWS JI Chem. Eng. News PD JUN 16 PY 1997 VL 75 IS 24 BP 7 EP 7 PG 1 WC Chemistry, Multidisciplinary; Engineering, Chemical SC Chemistry; Engineering GA XE363 UT WOS:A1997XE36300005 ER PT J AU Aronov, IE Berman, GP Campbell, DK Dudiy, SV AF Aronov, IE Berman, GP Campbell, DK Dudiy, SV TI Wigner function description of ac transport through a two-dimensional quantum point contact SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article ID QUANTIZED CONDUCTANCE; BALLISTIC-RESISTANCE; CONSTRICTION; CAPACITANCE; ADMITTANCE; ELECTRONS; SYSTEMS; FIELD; PUMP AB We have calculated the admittance of a two-dimensional quantum point contact (QPC) using a novel variant of the Wigner distribution function (WDF) formalism. In the semiclassical approximation, a Boltzmann-like equation is derived for the partial WDF describing both propagating and non-propagating electron modes in an effective potential generated by the adiabatic QPC. We show that this quantum kinetic approach leads to the well known stepwise behaviour of the real part of the admittance (the conductance), and of the imaginary part of the admittance (the emittance), in agreement with the latest results derived by Christen and Buttiker, which is determined by the number of propagating electron modes. It is shown that the emittance is sensitive to the geometry of the QPC, and can be controlled by the gate voltage. We have established that the emittance has contributions corresponding to both quantum inductance and quantum capacitance. Stepwise oscillations in the quantum inductance are determined by the harmonic mean of the velocities for the propagating modes, whereas the quantum capacitance is a significant mesoscopic manifestation of the nonpropagating (reflecting) modes. C1 LOS ALAMOS NATL LAB, CNLS, LOS ALAMOS, NM 87545 USA. UKRAINIAN ACAD SCI, INST RADIOPHYS & ELECT, UA-310085 KHARKOV, UKRAINE. LV KIRENSKII INST PHYS, KRASNOYARSK 660036, RUSSIA. UNIV ILLINOIS, DEPT PHYS, URBANA, IL 61801 USA. RP LOS ALAMOS NATL LAB, DIV THEORET, LOS ALAMOS, NM 87545 USA. NR 45 TC 8 Z9 8 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0953-8984 EI 1361-648X J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD JUN 16 PY 1997 VL 9 IS 24 BP 5089 EP 5103 DI 10.1088/0953-8984/9/24/009 PG 15 WC Physics, Condensed Matter SC Physics GA XF697 UT WOS:A1997XF69700009 ER PT J AU Rodriguez, JP AF Rodriguez, JP TI Decoupling of layered superconducting films in parallel magnetic field SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article ID HIGH-TEMPERATURE SUPERCONDUCTORS; PHASE-TRANSITIONS; XY-MODEL; QUARK CONFINEMENT; LATTICE MODELS; VORTEX-LATTICE; FLUX-LATTICE; 2 DIMENSIONS; VORTICES; BI2SR2CACU2O8-Y AB The issue of the decoupling of extreme type-IT superconducting thin films (lambda(L)-->infinity) with weakly Josephson-coupled layers in magnetic field parallel to the layers is considered via the corresponding frustrated XY model used to describe the mixed phase in the critical regime. For the general case of arbitrary field orientations such that the perpendicular magnetic field component is larger than the decoupling crossover scale characteristic of layered superconductors, we obtain independent parallel and perpendicular vortex lattices. Specializing to the double-layer case, we compute the parallel lower-critical field with entropic effects included, and find that it vanishes exponentially as the temperature approaches the layer decoupling transition in zero field. The parallel reversible magnetization is also calculated in this case, where we find that it shows a crossover phenomenon as a function of parallel field in the intermediate regime of the mixed phase in lieu of a true layer-decoupling transition. It is argued that such is the case for any finite number of layers, since the isolated double layer represents the weakest link. C1 CALIF STATE UNIV LOS ANGELES, DEPT PHYS & ASTRON, LOS ANGELES, CA 90032 USA. RP Rodriguez, JP (reprint author), LOS ALAMOS NATL LAB, DIV THEORET, LOS ALAMOS, NM 87545 USA. NR 54 TC 12 Z9 12 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL, ENGLAND BS1 6BE SN 0953-8984 J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD JUN 16 PY 1997 VL 9 IS 24 BP 5117 EP 5135 DI 10.1088/0953-8984/9/24/011 PG 19 WC Physics, Condensed Matter SC Physics GA XF697 UT WOS:A1997XF69700011 ER PT J AU Weimann, PA Jones, TD Hillmyer, MA Bates, FS Londono, JD Melnichenko, Y Wignall, GD Almdal, K AF Weimann, PA Jones, TD Hillmyer, MA Bates, FS Londono, JD Melnichenko, Y Wignall, GD Almdal, K TI Phase behavior of isotactic polypropylene-poly(ethylene/ethylethylene) random copolymer blends SO MACROMOLECULES LA English DT Article ID ANGLE NEUTRON-SCATTERING; SATURATED-HYDROCARBON POLYMERS; THERMODYNAMIC INTERACTIONS; TEMPERATURE-DEPENDENCE; POLY(1-BUTENE) BLENDS; MECHANICAL-PROPERTIES; MONOMER STRUCTURE; POLYPROPYLENE; MORPHOLOGY; MIXTURES AB The melt-state phase behavior of isotactic polypropylene (i-PP) blended with a series of poly(ethylene/ethylethylene) random copolymers has been investigated using small-angle neutron scattering (SANS). These PEExx copolymers, where xx is the percentage of ethylethylene (EE) units, were prepared by hydrogenation of anionically polymerized polybutadienes with controlled amounts of 1,2 addition. Random phase approximation (RPA) fits to the scattering data for blends of i-PP with a deuterated, low molecular weight PEE90 at 180 degrees C indicate a statistical segment length for i-PP that is 10% less than that reported previously. Scattering from blends of i-PP with higher molecular weight PEE90 and PEE73 at 180 degrees C can be quantitatively fit using the RPA theory with chi as the only adjustable parameter, indicating melt miscibility. PEE46 and PEE62 are strongly and marginally immiscible, respectively, with i-PP at 180 degrees C. These results establish a ''window'' in EE content in which these random copolymers can form single phase mixtures with i-PP. C1 UNIV MINNESOTA,DEPT CHEM ENGN & MAT SCI,MINNEAPOLIS,MN 55455. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RISO NATL LAB,DK-4000 ROSKILDE,DENMARK. OI Wignall, George/0000-0002-3876-3244; Bates, Frank/0000-0003-3977-1278; Almdal, Kristoffer/0000-0002-5490-9303 NR 60 TC 43 Z9 44 U1 1 U2 16 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD JUN 16 PY 1997 VL 30 IS 12 BP 3650 EP 3657 DI 10.1021/ma961383h PG 8 WC Polymer Science SC Polymer Science GA XE760 UT WOS:A1997XE76000030 ER PT J AU Abe, F Akimoto, H Akopian, A Albrow, MG Amendolia, SR Amidei, D Antos, J Aota, S Apollinari, G Asakawa, T Ashmanskas, W Atac, M Azfar, F AzziBacchetta, P Bacchetta, N Badgett, W Bagdasarov, S Bailey, MW Bao, J deBarbaro, P BarbaroGaltieri, A Barnes, VE Barnett, BA Barone, M Barzi, E Bauer, G Baumann, T Bedeschi, F Behrends, S Belforte, S Bellettini, G Bellinger, J Benjamin, D Benlloch, J Bensinger, J Benton, D Beretvas, A Berge, JP Berryhill, J Bertolucci, S Bevensee, B Bhatti, A Biery, K Binkley, M Bisello, D Blair, RE Blocker, C Bodek, A Bokhari, W Bolognesi, V Bolla, G Bortoletto, D Bourdeau, J Breccia, L Bromber, C Bruner, N BuckleyGeer, E Budd, HS Burkett, K Busetto, G ByonWagner, A Byrum, KL Cammerata, J Campagnari, C Campbell, M Caner, A Carithers, W Carlsmith, D Castro, A Cauz, D Cen, Y Cervelli, F Chang, PS Chang, PT Chao, HY Chapman, J Cheng, MT Chiarelli, G Chikamatsu, T Chiou, CN Christofek, L Cihangir, S Clark, AG Cobal, M Cocca, E Contreras, M Conway, J Cooper, J Cordelli, M Couyoumtzelis, C Crane, D CroninHennessy, D Culbertson, R Daniels, T DeJongh, F Delchamps, S DellAgnello, S DellOrso, M Demina, R Demortier, L Deninno, M Derwent, PF Devlin, T Dittmann, JR Donati, S Done, J Dorigo, T Dunn, A Eddy, N Einsweiler, K Elias, JE Ely, R Engels, E Errede, D Errede, S Fan, Q Feild, G Ferretti, C Fiori, I Flaugher, B Foster, GW Franklin, M Frautschi, M Freeman, J Friedman, J Frisch, H Fukui, Y Funaki, S Galeotti, S Gallinaro, M Ganel, O GarciaSciveres, M Garfinkel, AF Gay, C Geer, S Gerdes, DW Giannetti, P Giokaris, N Giromini, P Giusti, G Gladney, L Glenzinski, D Gold, M Gonzalez, J Gordon, A Goshaw, AT Gotra, Y Goulianos, K Grassmann, H Groer, L GrossoPilcher, C Guillian, G Guo, RS Haber, C Hafen, E Hahn, SR Hamilton, R Handler, R Hans, RM Happacher, F Hara, K Hardman, AD Harral, B Harris, RM Hauger, SA Hauser, J Hawk, C Hayashi, E Heinrich, J Hoffman, KD Hohlmann, M Holck, C Hollebeek, R Holloway, L Holscher, A Hong, S Houk, G Hu, P Huffman, BT Hughes, R Huston, J Huth, J Hylen, J Ikeda, H Incagli, M Incandela, J Introzzi, G Iwai, J Iwata, Y Jensen, H Joshi, U Kadel, RW Kajfasz, E Kambara, H Kamon, T Kaneko, T Karr, K Kasha, H Kato, Y Keaffaber, TA Keeble, L Kelley, K Kennedy, RD Kephart, R Kesten, P Kestenbaum, D Keup, RM Keutelian, H Keyvan, F Kharadia, B Kim, BJ Kim, DH Kim, HS Kim, SB Kim, SH Kim, YK Kirsch, L Koehn, P Kondo, K Konigsberg, J Kopp, S Kordas, K Korytov, A Koska, W Kovacs, E Kowald, W Krasberg, M Kroll, J Kruse, M Kuwabara, T Kuhlmann, SE Kuns, E Laasanen, AT Lami, S Lammel, S Lamoureux, JI LeCompte, T Leone, S Lewis, JD Limon, P Lindgren, M Liss, TM Lockyer, N Long, O Loomis, C Loreti, M Lu, J Lucchesi, D Lukens, P Lusin, S Lys, J Maeshima, K Maghakian, A Maksimovic, P Mangano, M Mansour, J Mariotti, M Marriner, JP Martin, A Matthews, JAJ Mattingly, R McIntyre, P Melese, P Menzione, A Meschi, E Metzler, S Miao, C Miao, T Michail, G Miller, R Minato, H Miscetti, S Mishina, M Mitsushio, H Miyamoto, T Miyashita, S Moggi, N Morita, Y Mueller, J Mukherjee, A Muller, T Murat, P Nakada, H Nakano, I Nelson, C Neuberger, D NewmanHolmes, C Ngan, CY Ninomiya, M Nodulman, L Oh, SH Ohl, KE Ohmoto, T Ohsugi, T Oishi, R Okabe, M Okusawa, T Oliveira, R Olsen, J Pagliarone, C Paoletti, R Papadimitriou, V Pappas, SP Parashar, N Park, S Parri, A Patrick, J Pauletta, G Paulini, M Perazzo, A Pescara, L Peters, MD Phillips, TJ Piacentino, G Pillai, M Pitts, KT Plunkett, R Pondrom, L Proudfoot, J Ptohos, F Punzi, G Ragan, K Reher, D Ribon, A Rimondi, F Ristori, L Robertson, WJ Rodrigo, T Rolli, S Romano, J Rosenson, L Roser, R Sakumoto, WK Saltzberg, D Sansoni, A Santi, L Sato, H Schlabach, P Schmidt, EE Schmidt, MP Scribano, A Segler, S Seidel, S Seiya, Y Sganos, G Shapiro, MD Shaw, NM Shen, Q Shepard, PF Shimojima, M Shochet, M Siegrist, J Sill, A Sinervo, P Singh, P Skarha, J Sliwa, K Snider, FD Song, T Spalding, J Speer, T Sphicas, P Spinella, F Spiropulu, M Spiegel, L Stanco, L Steele, J Stefanini, A Strahl, K Strait, J Strohmer, R Stuart, D Sullivan, G Soumarokov, A Sumorok, K Suzuki, J Takada, T Takahashi, T Takano, T Takikawa, K Tamura, N Tannenbaum, B Tartarelli, F Taylor, W Teng, PK Teramoto, Y Tether, S Theriot, D Thomas, TL Thun, R Timko, M Tipton, P Titov, A Tkaczyk, S Toback, D Tollefson, K Tollestrup, A Toyoda, H Trischuk, W deTroconiz, JF Truitt, S Tseng, J Turini, N Uchida, T Uemura, N Ukegawa, F Unal, G Valls, J vandenBrink, SC Vejcik, S Velev, G Vidal, R Vondracek, M Vucinic, D Wagner, RG Wagner, RL Wahl, J Wallace, NB Walsh, AM Wang, C Wang, CH Wang, J Wang, MJ Wang, QF Warburton, A Watts, T Webb, R Wei, C Wendt, C Wenzel, H Wester, WC Wicklund, AB Wicklund, E Wilkinson, R Williams, HH Wilson, P Winer, BL Winn, D Wolinski, D Wolinski, J Worm, S Wu, X Wyss, J Yagil, A Yao, W Yasuoka, K Ye, Y Yeh, GP Yeh, P Yin, M Yoh, J Yosef, C Yoshida, T Yovanovitch, D Yu, I Yu, L Yun, JC Zanetti, A Zetti, F Zhang, L Zhang, W Zucchelli, S AF Abe, F Akimoto, H Akopian, A Albrow, MG Amendolia, SR Amidei, D Antos, J Aota, S Apollinari, G Asakawa, T Ashmanskas, W Atac, M Azfar, F AzziBacchetta, P Bacchetta, N Badgett, W Bagdasarov, S Bailey, MW Bao, J deBarbaro, P BarbaroGaltieri, A Barnes, VE Barnett, BA Barone, M Barzi, E Bauer, G Baumann, T Bedeschi, F Behrends, S Belforte, S Bellettini, G Bellinger, J Benjamin, D Benlloch, J Bensinger, J Benton, D Beretvas, A Berge, JP Berryhill, J Bertolucci, S Bevensee, B Bhatti, A Biery, K Binkley, M Bisello, D Blair, RE Blocker, C Bodek, A Bokhari, W Bolognesi, V Bolla, G Bortoletto, D Bourdeau, J Breccia, L Bromber, C Bruner, N BuckleyGeer, E Budd, HS Burkett, K Busetto, G ByonWagner, A Byrum, KL Cammerata, J Campagnari, C Campbell, M Caner, A Carithers, W Carlsmith, D Castro, A Cauz, D Cen, Y Cervelli, F Chang, PS Chang, PT Chao, HY Chapman, J Cheng, MT Chiarelli, G Chikamatsu, T Chiou, CN Christofek, L Cihangir, S Clark, AG Cobal, M Cocca, E Contreras, M Conway, J Cooper, J Cordelli, M Couyoumtzelis, C Crane, D CroninHennessy, D Culbertson, R Daniels, T DeJongh, F Delchamps, S DellAgnello, S DellOrso, M Demina, R Demortier, L Deninno, M Derwent, PF Devlin, T Dittmann, JR Donati, S Done, J Dorigo, T Dunn, A Eddy, N Einsweiler, K Elias, JE Ely, R Engels, E Errede, D Errede, S Fan, Q Feild, G Ferretti, C Fiori, I Flaugher, B Foster, GW Franklin, M Frautschi, M Freeman, J Friedman, J Frisch, H Fukui, Y Funaki, S Galeotti, S Gallinaro, M Ganel, O GarciaSciveres, M Garfinkel, AF Gay, C Geer, S Gerdes, DW Giannetti, P Giokaris, N Giromini, P Giusti, G Gladney, L Glenzinski, D Gold, M Gonzalez, J Gordon, A Goshaw, AT Gotra, Y Goulianos, K Grassmann, H Groer, L GrossoPilcher, C Guillian, G Guo, RS Haber, C Hafen, E Hahn, SR Hamilton, R Handler, R Hans, RM Happacher, F Hara, K Hardman, AD Harral, B Harris, RM Hauger, SA Hauser, J Hawk, C Hayashi, E Heinrich, J Hoffman, KD Hohlmann, M Holck, C Hollebeek, R Holloway, L Holscher, A Hong, S Houk, G Hu, P Huffman, BT Hughes, R Huston, J Huth, J Hylen, J Ikeda, H Incagli, M Incandela, J Introzzi, G Iwai, J Iwata, Y Jensen, H Joshi, U Kadel, RW Kajfasz, E Kambara, H Kamon, T Kaneko, T Karr, K Kasha, H Kato, Y Keaffaber, TA Keeble, L Kelley, K Kennedy, RD Kephart, R Kesten, P Kestenbaum, D Keup, RM Keutelian, H Keyvan, F Kharadia, B Kim, BJ Kim, DH Kim, HS Kim, SB Kim, SH Kim, YK Kirsch, L Koehn, P Kondo, K Konigsberg, J Kopp, S Kordas, K Korytov, A Koska, W Kovacs, E Kowald, W Krasberg, M Kroll, J Kruse, M Kuwabara, T Kuhlmann, SE Kuns, E Laasanen, AT Lami, S Lammel, S Lamoureux, JI LeCompte, T Leone, S Lewis, JD Limon, P Lindgren, M Liss, TM Lockyer, N Long, O Loomis, C Loreti, M Lu, J Lucchesi, D Lukens, P Lusin, S Lys, J Maeshima, K Maghakian, A Maksimovic, P Mangano, M Mansour, J Mariotti, M Marriner, JP Martin, A Matthews, JAJ Mattingly, R McIntyre, P Melese, P Menzione, A Meschi, E Metzler, S Miao, C Miao, T Michail, G Miller, R Minato, H Miscetti, S Mishina, M Mitsushio, H Miyamoto, T Miyashita, S Moggi, N Morita, Y Mueller, J Mukherjee, A Muller, T Murat, P Nakada, H Nakano, I Nelson, C Neuberger, D NewmanHolmes, C Ngan, CY Ninomiya, M Nodulman, L Oh, SH Ohl, KE Ohmoto, T Ohsugi, T Oishi, R Okabe, M Okusawa, T Oliveira, R Olsen, J Pagliarone, C Paoletti, R Papadimitriou, V Pappas, SP Parashar, N Park, S Parri, A Patrick, J Pauletta, G Paulini, M Perazzo, A Pescara, L Peters, MD Phillips, TJ Piacentino, G Pillai, M Pitts, KT Plunkett, R Pondrom, L Proudfoot, J Ptohos, F Punzi, G Ragan, K Reher, D Ribon, A Rimondi, F Ristori, L Robertson, WJ Rodrigo, T Rolli, S Romano, J Rosenson, L Roser, R Sakumoto, WK Saltzberg, D Sansoni, A Santi, L Sato, H Schlabach, P Schmidt, EE Schmidt, MP Scribano, A Segler, S Seidel, S Seiya, Y Sganos, G Shapiro, MD Shaw, NM Shen, Q Shepard, PF Shimojima, M Shochet, M Siegrist, J Sill, A Sinervo, P Singh, P Skarha, J Sliwa, K Snider, FD Song, T Spalding, J Speer, T Sphicas, P Spinella, F Spiropulu, M Spiegel, L Stanco, L Steele, J Stefanini, A Strahl, K Strait, J Strohmer, R Stuart, D Sullivan, G Soumarokov, A Sumorok, K Suzuki, J Takada, T Takahashi, T Takano, T Takikawa, K Tamura, N Tannenbaum, B Tartarelli, F Taylor, W Teng, PK Teramoto, Y Tether, S Theriot, D Thomas, TL Thun, R Timko, M Tipton, P Titov, A Tkaczyk, S Toback, D Tollefson, K Tollestrup, A Toyoda, H Trischuk, W deTroconiz, JF Truitt, S Tseng, J Turini, N Uchida, T Uemura, N Ukegawa, F Unal, G Valls, J vandenBrink, SC Vejcik, S Velev, G Vidal, R Vondracek, M Vucinic, D Wagner, RG Wagner, RL Wahl, J Wallace, NB Walsh, AM Wang, C Wang, CH Wang, J Wang, MJ Wang, QF Warburton, A Watts, T Webb, R Wei, C Wendt, C Wenzel, H Wester, WC Wicklund, AB Wicklund, E Wilkinson, R Williams, HH Wilson, P Winer, BL Winn, D Wolinski, D Wolinski, J Worm, S Wu, X Wyss, J Yagil, A Yao, W Yasuoka, K Ye, Y Yeh, GP Yeh, P Yin, M Yoh, J Yosef, C Yoshida, T Yovanovitch, D Yu, I Yu, L Yun, JC Zanetti, A Zetti, F Zhang, L Zhang, W Zucchelli, S TI Evidence for W+W- production in (p)over-bar-p collisions at root s=1.8 TeV SO PHYSICAL REVIEW LETTERS LA English DT Article ID TOP-QUARK PRODUCTION; P(P)OVER-BAR COLLISIONS; PAIR PRODUCTION; FERMILAB; DETECTOR; GAMMA; WWZ AB We present results of a search for W+W- production through the leptonic decay channel W+W- --> l(+)l(-) in <(p)over bar p> collision at root s = 1.8 TeV. In a 108 pb(-1) data sample recorded with the Collider Detector at Fermilab, five W+W- candidates are found with an expected standard model background of 1.2 +/- 0.3 events. The W+W- production cross section is measured to be sigma(<(p)over bar p> --> W+W-) = 10.2(-5.1)(+6.3)(stat) +/- 1.6(syst) pb, in agreement with the standard model prediction. Limits on WW gamma and WWZ anomalous couplings are presented. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. UNIV BOLOGNA,IST NAZL FIS NUCL,I-40127 BOLOGNA,ITALY. BRANDEIS UNIV,WALTHAM,MA 02264. UNIV CALIF LOS ANGELES,LOS ANGELES,CA 90024. UNIV CHICAGO,CHICAGO,IL 60638. DUKE UNIV,DURHAM,NC 28708. FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. UNIV FLORIDA,GAINESVILLE,FL 33611. IST NAZL FIS NUCL,LAB NAZL FRASCATI,I-00044 FRASCATI,ITALY. UNIV GENEVA,CH-1211 GENEVA 4,SWITZERLAND. HARVARD UNIV,CAMBRIDGE,MA 02138. HIROSHIMA UNIV,HIGASHIHIROSHIMA 724,JAPAN. UNIV ILLINOIS,URBANA,IL 61801. MCGILL UNIV,INST PARTICLE PHYS,MONTREAL,PQ H3A 2T8,CANADA. UNIV TORONTO,TORONTO,ON M5S 1A7,CANADA. JOHNS HOPKINS UNIV,BALTIMORE,MD 21218. ERNEST ORLANDO LAWRENCE BERKELEY NALT LAB,BERKELEY,CA 94720. MIT,CAMBRIDGE,MA 02139. UNIV MICHIGAN,ANN ARBOR,MI 48109. MICHIGAN STATE UNIV,E LANSING,MI 48824. UNIV NEW MEXICO,ALBUQUERQUE,NM 87132. OHIO STATE UNIV,COLUMBUS,OH 43320. OSAKA CITY UNIV,OSAKA 558,JAPAN. UNIV PADUA,IST NAZL FIS NUCL,I-36132 PADUA,ITALY. UNIV PENN,PHILADELPHIA,PA 19104. UNIV PISA,IST NAZL FIS NUCL,I-56100 PISA,ITALY. SCUOLA NORMALE SUPER PISA,I-56100 PISA,ITALY. UNIV PITTSBURGH,PITTSBURGH,PA 15270. PURDUE UNIV,W LAFAYETTE,IN 47907. UNIV ROCHESTER,ROCHESTER,NY 14628. ROCKEFELLER UNIV,NEW YORK,NY 10021. RUTGERS STATE UNIV,PISCATAWAY,NJ 08854. ACAD SINICA,TAIPEI 11530,TAIWAN. TEXAS A&M UNIV,COLLEGE STN,TX 77843. TEXAS TECH UNIV,LUBBOCK,TX 79409. UNIV TSUKUBA,TSUKUBA,IBARAKI 315,JAPAN. UNIV WISCONSIN,MADISON,WI 53806. YALE UNIV,NEW HAVEN,CT 06511. TUFTS UNIV,MEDFORD,MA 02155. RP Abe, F (reprint author), NATL LAB HIGH ENERGY PHYS,TSUKUBA,IBARAKI 315,JAPAN. RI Vucinic, Dejan/C-2406-2008; Azzi, Patrizia/H-5404-2012; Punzi, Giovanni/J-4947-2012; Chiarelli, Giorgio/E-8953-2012; Warburton, Andreas/N-8028-2013; Kim, Soo-Bong/B-7061-2014; Paulini, Manfred/N-7794-2014; Introzzi, Gianluca/K-2497-2015 OI Azzi, Patrizia/0000-0002-3129-828X; Punzi, Giovanni/0000-0002-8346-9052; Chiarelli, Giorgio/0000-0001-9851-4816; Warburton, Andreas/0000-0002-2298-7315; Paulini, Manfred/0000-0002-6714-5787; Introzzi, Gianluca/0000-0002-1314-2580 NR 20 TC 52 Z9 52 U1 0 U2 3 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 JUN 16 PY 1997 VL 78 IS 24 BP 4536 EP 4540 DI 10.1103/PhysRevLett.78.4536 PG 5 WC Physics, Multidisciplinary SC Physics GA XE571 UT WOS:A1997XE57100002 ER PT J AU Dias, EWB Chakraborty, HS Deshmukh, PC Manson, ST Hemmers, O Glans, P Hansen, DL Wang, H Whitfield, SB Lindle, DW Wehlitz, R Levin, JC Sellin, IA Perera, RCC AF Dias, EWB Chakraborty, HS Deshmukh, PC Manson, ST Hemmers, O Glans, P Hansen, DL Wang, H Whitfield, SB Lindle, DW Wehlitz, R Levin, JC Sellin, IA Perera, RCC TI Breakdown of the independent particle approximation in high-energy photoionization SO PHYSICAL REVIEW LETTERS LA English DT Article ID RANDOM-PHASE APPROXIMATION; ATOMS AB The independent particle approximation is shown to break down for the photoionization of both inner and outer nl (l > 0) electrons of all atoms, at high enough energy, owing to interchannel interactions with the nearby ns photoionization channels. The effect is illustrated for Ne 2p in the 1 keV photon energy range through a comparison of theory and experiment. The implications for x-ray photoelectron spectroscopy of molecules and condensed matter are discussed. C1 GEORGIA STATE UNIV, DEPT PHYS & ASTRON, ATLANTA, GA 30303 USA. UNIV NEVADA, DEPT CHEM, LAS VEGAS, NV 89154 USA. UNIV TENNESSEE, DEPT PHYS & ASTRON, KNOXVILLE, TN 37996 USA. UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA. RP Dias, EWB (reprint author), INDIAN INST TECHNOL, DEPT PHYS, MADRAS 600036, TAMIL NADU, INDIA. NR 21 TC 82 Z9 82 U1 0 U2 6 PU AMER 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 JUN 16 PY 1997 VL 78 IS 24 BP 4553 EP 4556 DI 10.1103/PhysRevLett.78.4553 PG 4 WC Physics, Multidisciplinary SC Physics GA XE571 UT WOS:A1997XE57100006 ER PT J AU Cheng, WH Sessler, AM Wurtele, JS AF Cheng, WH Sessler, AM Wurtele, JS TI Damping of the transverse head-tail instability by periodic modulation of the chromaticity SO PHYSICAL REVIEW LETTERS LA English DT Article AB An analytical and numerical study of the suppression of the transverse head-tail instability by modulating the chromaticity,over a synchrotron period is presented. We find that a threshold can be developed, and it can be increased to a value larger than the strong head-tail instability threshold. The stability criterion derived agrees very well with the simulations. The underlying physical mechanisms of the damping scheme are rotation of the head-tail phase such that the instability does not occur, and Landau damping due to the incoherent betatron tune spread generated by the varying chromaticity. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP Cheng, WH (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. RI wurtele, Jonathan/J-6278-2016 OI wurtele, Jonathan/0000-0001-8401-0297 NR 19 TC 3 Z9 3 U1 0 U2 0 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 JUN 16 PY 1997 VL 78 IS 24 BP 4565 EP 4568 DI 10.1103/PhysRevLett.78.4565 PG 4 WC Physics, Multidisciplinary SC Physics GA XE571 UT WOS:A1997XE57100009 ER PT J AU Litvinenko, VN Burnham, B Emamian, M Hower, N Madey, JMJ Morcombe, P OShea, PG Park, SH Sachtschale, R Straub, KD Swift, G Wang, P Wu, Y Canon, RS Howell, CR Roberson, NR Schreiber, EC Spraker, M Tornow, W Weller, HR Pinayev, IV Gavrilov, NG Fedotov, MG Kulipanov, GN Kurkin, GY Mikhailov, SF Popik, VM Skrinsky, AN Vinokurov, NA Norum, BE Lumpkin, A Yang, B AF Litvinenko, VN Burnham, B Emamian, M Hower, N Madey, JMJ Morcombe, P OShea, PG Park, SH Sachtschale, R Straub, KD Swift, G Wang, P Wu, Y Canon, RS Howell, CR Roberson, NR Schreiber, EC Spraker, M Tornow, W Weller, HR Pinayev, IV Gavrilov, NG Fedotov, MG Kulipanov, GN Kurkin, GY Mikhailov, SF Popik, VM Skrinsky, AN Vinokurov, NA Norum, BE Lumpkin, A Yang, B TI Gamma-ray production in a storage ring free-electron laser SO PHYSICAL REVIEW LETTERS LA English DT Article ID COMPTON AB A nearly monochromatic beam of 100% linearly polarized gamma rays has been produced via Compton backscattering inside a free electron laser optical cavity. The beam of 12.2 MeV gamma rays was obtained by backscattering 379.4 nm free-electron laser photons from 500 MeV electron's circulating in a storage ring. A detailed description of the gamma-ray beam and the outlook for future improvements are presented. C1 TRIANGLE UNIV NUCL LAB,DURHAM,NC 27708. BUDKER INST NUCL PHYS,NOVOSIBIRSK 630090,RUSSIA. UNIV VIRGINIA,CHARLOTTESVILLE,VA 22901. ARGONNE NATL LAB,ADV PHOTON SOURCE,ARGONNE,IL 60439. RP Litvinenko, VN (reprint author), DUKE UNIV,DEPT PHYS,FREE ELECTRON LASER LAB,DURHAM,NC 27708, USA. NR 18 TC 163 Z9 165 U1 1 U2 5 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 JUN 16 PY 1997 VL 78 IS 24 BP 4569 EP 4572 DI 10.1103/PhysRevLett.78.4569 PG 4 WC Physics, Multidisciplinary SC Physics GA XE571 UT WOS:A1997XE57100010 ER PT J AU Douglas, MR Deeney, C Roderick, NF AF Douglas, MR Deeney, C Roderick, NF TI Effect of sheath curvature on Rayleigh-Taylor mitigation in high-velocity uniform-fill, Z-pinch implosions SO PHYSICAL REVIEW LETTERS LA English DT Article ID LINERS AB Recent gas puff experiments on the 7-MA Saturn machine identified a curved surface at the plasma-vacuum interface during the run-in phase of the implosion. Incorporating this topology into a corresponding two-dimensional magnetohydrodynamic calculation revealed that this curvature plays a surprisingly dominant role in mitigating Rayleigh-Taylor (RT) growth prior to stagnation. Calculations with both Saturn and representative PBFA-Z parameters show that sheath curvature contributes to the reduction in RT growth by convecting the instability to the edges of the pinch faster than it can grow. C1 UNIV NEW MEXICO,ALBUQUERQUE,NM 87102. RP Douglas, MR (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 27 TC 41 Z9 43 U1 1 U2 2 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 JUN 16 PY 1997 VL 78 IS 24 BP 4577 EP 4580 DI 10.1103/PhysRevLett.78.4577 PG 4 WC Physics, Multidisciplinary SC Physics GA XE571 UT WOS:A1997XE57100012 ER PT J AU Boehler, R Ross, M Boercker, DB AF Boehler, R Ross, M Boercker, DB TI Melting of LiF and NaCl to 1 Mbar: Systematics of ionic solids at extreme conditions SO PHYSICAL REVIEW LETTERS LA English DT Article ID HIGH-PRESSURES; EARTHS CORE; IRON; TEMPERATURES; MGO AB We report the first diamond cell data for the melting curves of LIF and NaCl up to 1 Mbar (100 GPa). The melting curve of NaCl is in agreement with shock data and shows a break in slope at 290 kbar due to the B1(NaCl)-B2(CsCl) transition. LiF remains B1 to the highest pressure, and molecular dynamic simulations predict that molten LIF retains a simple-cubic B1-like structure. A plot of the recent Mainz diamond anvil melting curves for MgO, LiF, KBr, KCI, CsI, and NaCl shows that at very high pressure all the melting curves have very similar slopes approaching a value of order 1-2 K/kbar. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551. RP Boehler, R (reprint author), MAX PLANCK INST CHEM,POSTFACH 3060,D-55020 MAINZ,GERMANY. NR 27 TC 103 Z9 104 U1 1 U2 21 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 JUN 16 PY 1997 VL 78 IS 24 BP 4589 EP 4592 DI 10.1103/PhysRevLett.78.4589 PG 4 WC Physics, Multidisciplinary SC Physics GA XE571 UT WOS:A1997XE57100015 ER PT J AU Sawicki, M Arnold, E Ebrahimi, S Duell, T Jin, S Wood, T Chakrabarti, R Peters, J Wan, Y Samara, G Weier, HUG Udar, N Passaro, E Srivatsan, ES AF Sawicki, M Arnold, E Ebrahimi, S Duell, T Jin, S Wood, T Chakrabarti, R Peters, J Wan, Y Samara, G Weier, HUG Udar, N Passaro, E Srivatsan, ES TI A transcript map encompassing the multiple endocrine neoplasia type-1 (MEN1) locus on chromosome 11q13 SO GENOMICS LA English DT Article ID HUMAN Y-CHROMOSOME; CDNA SELECTION; PARATHYROID TUMORS; LINKAGE ANALYSIS; SMALL REGION; GENE; MARKERS; PROTEIN; DNA; IDENTIFICATION AB A transcription map of a 1200-kb region encompassing the MEN1 locus was constructed by direct cDNA selection and mapping ESTs. A total of 29 genes were mapped. Ten transcripts were identified by cDNA selection of a focused 300-kb genomic region telomeric to the MEN1 consensus region. Since many of the sequences cloned by cDNA selection also identified ESTs from the region, 19 additional RH-mapped ESTs were mapped to the entire contig region by CR amplification of genomic clones. Nine known genes, 2 putative human homologues to mouse genes, and is novel transcripts map to the region. Transcripts that map to the MEN1 interval PYGM-D11S449 include SGC35223, IB1256, AA147620, ZFM1, FAU, and CAPN1. The latter 3 known genes have already been excluded as candidate MEN1 genes. The 2 putative human homologues of mouse genes Ltbp2 and Spa-1 may be candidate tumor suppressor genes, but they map telomeric to D11S449. Although both of these genes map outside the MEN1 consensus region they may play a role in sporadic endocrine tumors independent of the MEN1 gene or in other tumors, such as breast cancer, that have loss of heterozygosity within this region. (C) 1997 Academic Press. C1 UNIV CALIF LOS ANGELES,DEPT PATHOL,LOS ANGELES,CA 90073. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV LIFE SCI,BERKELEY,CA 94720. UNIV MUNICH,MED KLIN 3,D-80539 MUNICH,GERMANY. CHILDRENS HOSP LOS ANGELES,DEPT PATHOL,LOS ANGELES,CA 90027. HARBOR UCLA MED CTR,DEPT PATHOL,TORRANCE,CA 90509. RP Sawicki, M (reprint author), W LOS ANGELES VET AFFAIRS MED CTR,DEPT SURG W112,MOL BIOL CORE UNIT,LOS ANGELES,CA 90073, USA. NR 46 TC 11 Z9 11 U1 0 U2 1 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0888-7543 J9 GENOMICS JI Genomics PD JUN 15 PY 1997 VL 42 IS 3 BP 405 EP 412 DI 10.1006/geno.1997.4773 PG 8 WC Biotechnology & Applied Microbiology; Genetics & Heredity SC Biotechnology & Applied Microbiology; Genetics & Heredity GA XG519 UT WOS:A1997XG51900006 PM 9205112 ER PT J AU Hwang, S Kuo, WL Cochran, JF Guzman, RC Tsukamoto, T Bandyopadhyay, G Myambo, K Collins, CC AF Hwang, S Kuo, WL Cochran, JF Guzman, RC Tsukamoto, T Bandyopadhyay, G Myambo, K Collins, CC TI Assignment of HMAT1, the human homolog of the murine mammary transforming gene (MAT1) associated with tumorigenesis, to 1q21.1, a region frequently gained in human breast cancers SO GENOMICS LA English DT Article ID MOUSE C1 UNIV CALIF SAN FRANCISCO,SAN FRANCISCO,CA 94143. UNIV CALIF BERKELEY,DEPT CELL & MOL BIOL,CANC RES LAB,BERKELEY,CA 94720. RP Hwang, S (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,MS74-157,BERKELEY,CA 94720, USA. FU NCI NIH HHS [CA63369]; PHS HHS [49374A] NR 9 TC 16 Z9 17 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 0888-7543 J9 GENOMICS JI Genomics PD JUN 15 PY 1997 VL 42 IS 3 BP 540 EP 542 DI 10.1006/geno.1997.4768 PG 3 WC Biotechnology & Applied Microbiology; Genetics & Heredity SC Biotechnology & Applied Microbiology; Genetics & Heredity GA XG519 UT WOS:A1997XG51900027 PM 9205133 ER PT J AU Stockman, HW Li, CH Wilson, JL AF Stockman, HW Li, CH Wilson, JL TI A lattice-gas and lattice Boltzmann study of mixing at continuous fracture junctions: Importance of boundary conditions SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID NAVIER-STOKES EQUATION; AUTOMATA; MODELS; SIMULATION; TRANSPORT; FLUIDS AB The lattice-gas automata and lattice Boltzmann (BGK) methods were used to estimate the mixing of fluid streams at a continuous fracture junction, for Peclet number (Pe) from 0 to 1547. Agreement with experimental results is good, particularly at Pe less than or equal to 25. At low Pe, a large fracture length/width is needed to obtain accurate mixing ratios (M-r). For a 90 degrees intersection of two fractures with equal widths and flow rates, M-r approaches 0.5 (complete mixing) at Pe approximate to 1. At the highest Pe studied, M-r = 0.022, in contrast with the streamline routing prediction M-r = 0. C1 INTERA,ALBUQUERQUE,NM 87102. NEW MEXICO INST MIN & TECHNOL,DEPT GEOSCI,SOCORRO,NM 87801. RP Stockman, HW (reprint author), SANDIA NATL LABS,GEOCHEM DEPT 6118,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 19 TC 39 Z9 40 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 JUN 15 PY 1997 VL 24 IS 12 BP 1515 EP 1518 DI 10.1029/97GL51471 PG 4 WC Geosciences, Multidisciplinary SC Geology GA XF904 UT WOS:A1997XF90400020 ER PT J AU Williams, PT Baker, AJ AF Williams, PT Baker, AJ TI Numerical simulations of laminar flow over a 3D backward-facing step SO INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS LA English DT Article DE backward-facing step; laminar flow; Navier-Stokes; finite elements; 3D ID NAVIER-STOKES EQUATIONS; INCOMPRESSIBLE FLOWS; BOUNDARY-CONDITIONS; ALGORITHM; PREDICTIONS; SYSTEMS; STEADY; SCHEME AB A numerical investigation of laminar flow over a three-dimensional backward-facing step is presented with comparisons with detailed experimental data, available in the literature, serving to validate the numerical results. The continuity constraint method, implemented via a finite element weak statement, was employed to solve the unsteady three-dimensional Navier-Stokes equations for incompressible laminar isothermal flow. Two-dimensional numerical simulations of this step geometry underestimate the experimentally determined extent of the primary separation region for Reynolds numbers Re greater than 400. It has been postulated that this disagreement between physical and computational experiments is due to the onset of three-dimensional flow near Re approximate to 400. This paper presents a full three-dimensional simulation of the step geometry for 100 less than or equal to Re less than or equal to 800 and correctly predicts the primary reattachment lengths, thus confirming the influence of three-dimensionality. Previous numerical studies have discussed possible instability modes which could induce a sudden onset of three-dimensional flow at certain critical Reynolds numbers. The current study explores the influence of the sidewall on the development of three-dimensional flow for Re>400. Of particular interest is the characterization of three-dimensional vortices in the primary separation region immediately downstream of the step. The complex interaction of a wall jet, located at the step plane near the sidewall, with the mainstream flow reveals a mechanism for the increasing penetration (with increasing Reynolds number) of three-dimensional how structures into a region of essentially two-dimensional flow near the midplane of the channel. The character and extent of the sidewall-induced flow are investigated for 100 less than or equal to Re less than or equal to 800. (C) 1997 by John Wiley & Sons, Ltd. C1 UNIV TENNESSEE,DEPT ENGN SCI & MECH,KNOXVILLE,TN 37996. RP Williams, PT (reprint author), OAK RIDGE NATL LAB,COMPUTAT PHYS & ENGN DIV,OAK RIDGE,TN 37831, USA. NR 42 TC 84 Z9 88 U1 0 U2 9 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0271-2091 J9 INT J NUMER METH FL JI Int. J. Numer. Methods Fluids PD JUN 15 PY 1997 VL 24 IS 11 BP 1159 EP 1183 DI 10.1002/(SICI)1097-0363(19970615)24:11<1159::AID-FLD534>3.0.CO;2-R PG 25 WC Computer Science, Interdisciplinary Applications; Mathematics, Interdisciplinary Applications; Mechanics; Physics, Fluids & Plasmas SC Computer Science; Mathematics; Mechanics; Physics GA XB303 UT WOS:A1997XB30300005 ER PT J AU Pinnaduwage, LA Datskos, PG AF Pinnaduwage, LA Datskos, PG TI Electron attachment to excited states of silane: Implications for plasma processing discharges SO JOURNAL OF APPLIED PHYSICS LA English DT Review ID NEGATIVE-ION DENSITIES; RADIO-FREQUENCY PLASMAS; SILICON THIN-FILMS; DISSOCIATIVE ATTACHMENT; RF DISCHARGES; METHYLATED DERIVATIVES; SUPEREXCITED STATES; POSITIVE-IONS; NITRIC-OXIDE; H FORMATION AB Observation of enhanced negative-ion formation in ArF-excimer-laser irradiated silane was reported in a recent paper [L. A. Pinnaduwage, M. Z. Martin, and L. G. Christophorou, Appl. Phys. Lett. 65, 2571 (1994)]. In that paper, preliminary evidence was presented to show that highly excited electronic states of silane or its photofragments could be responsible for the observed enhanced negative-ion formation. In the present paper, we report evidence, obtained using a new experimental technique, that the electron attaching species are high-Rydberg (HR) states of silane indirectly populated via laser irradiation and show that an absolute lower bound for the corresponding electron attachment rate constant is similar to 4 X 10(-7) cm(3) s(-1). The initial capture of the electron by the HR states is likely to be a diabatic process and the large polarizabilities associated with the HR states appear to be responsible for the observed large electron attachment rate constants, We also measured electron attachment to thermally excited vibrational states of the ground electronic state of silane, which showed no measurable electron attachment up to 750 K. Implications of these observations in modeling of silane discharges used for plasma processing of amorphous silicon are discussed. It is also pointed out that large negative ion formation observed in many ''weakly electronegative'' plasma processing gas discharges could be due to enhanced electron attachment to HR states: such states could be populated via direct electron impact and/or via excitation transfer from the metastable states of rare gases that are commonly used in these processing discharges. (C) 1997 American Institute of Physics. C1 UNIV TENNESSEE, DEPT PHYS, KNOXVILLE, TN 37996 USA. RP OAK RIDGE NATL LAB, DIV LIFE SCI, POB 2008, OAK RIDGE, TN 37831 USA. NR 117 TC 27 Z9 27 U1 1 U2 5 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-8979 EI 1089-7550 J9 J APPL PHYS JI J. Appl. Phys. PD JUN 15 PY 1997 VL 81 IS 12 BP 7715 EP 7727 DI 10.1063/1.365381 PG 13 WC Physics, Applied SC Physics GA XF588 UT WOS:A1997XF58800002 ER PT J AU Yang, FQ He, XY Dembo, M Li, JCM AF Yang, FQ He, XY Dembo, M Li, JCM TI Impression creep of a viscous fluid SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID SUBMERGED CIRCULAR-CYLINDER; FREE-SURFACE FLOW; DEFORMABLE INTERFACE; THIN-FILMS; MOTION; HARDNESS; FATIGUE AB The impression test of a Newtonian fluid under a constant load and for a small Reynolds number flow was simulated by using the finite element method. It is found that the penetration velocity is a constant if the surface tension/viscosity ratio is less than 0.1 cm/s, the product of surface tension and indenter radius is less than 0.05 of the applied load, and the penetration depth is less than 1/3 of the indenter radius. Such constant penetration velocity is proportional to the applied load and inversely proportional to the viscosity and the indenter radius. The stick or slip boundary condition at the interface between the indenter and the fluid has no effect on the penetration velocity under these conditions. (C) 1997 American Institute of Physics. C1 LOS ALAMOS NATL LAB, THEORET BIOL & BIOPHYS GRP T 10, LOS ALAMOS, NM 87545 USA. RP Yang, FQ (reprint author), UNIV ROCHESTER, DEPT MECH ENGN, ROCHESTER, NY 14627 USA. RI Dembo, Micah/C-2755-2013 NR 31 TC 2 Z9 2 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JUN 15 PY 1997 VL 81 IS 12 BP 7751 EP 7756 DI 10.1063/1.365384 PG 6 WC Physics, Applied SC Physics GA XF588 UT WOS:A1997XF58800007 ER PT J AU Noh, M Shin, HJ Jeong, K Spear, J Johnson, DC Kevan, SD Warwick, T AF Noh, M Shin, HJ Jeong, K Spear, J Johnson, DC Kevan, SD Warwick, T TI Lateral structure of (TiSe2)(n)(NbSe2)(m) superlattices SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID X-RAY-ABSORPTION; TRANSITION-METALS AB The structures of a series of (TiSe2)(n)(NbSe2)(m) superlattices grown through controlled crystallization of designed multilayer reactants have been studied. X-ray diffraction of the data of the superlattices after crystallization show considerable preferred orientation, with the basal plane of the dichalcogenide structure parallel to the substrate to within 0.1 degrees. Lattice refinement using the observed (00l) diffraction maxima yields lattice parameters along the c axis that are consistent with those expected based on the target superlattices and lattice parameters of the binary constituents, These (00l) diffraction data, however, contain no information about the crystalline structure in the ab plane of the superlattice associated with the preferred c-axis orientation. Off-specular x-ray diffraction (XRD), scanning electron microscopy, and scanning transmission x-ray microscopy (STXM) were used to explore the structure and homogeneity of the superlattices in the ab plane. XRD results rule out preferred long-range orientational order of the ab plane. Between grains, both the backscattered electron images and STXM images show grain domain structure in the ab plane with a characteristic grain domain size of approximately 50 mu m. X-ray absorption microscopy in the STXM mode obtained at the Ti L-2,L-3 edge shows that the titanium in the superlattices is present as both octahedral Ti consistent with the TiSe2 structure and metallic Ti. A comparison of the data obtained from these techniques highlights chemical information, which can be deduced on a submicrometer range from the space resolved spectra obtained using STXM. (C) 1997 American Institute of Physics. C1 ADV LIGHT SOURCE,BERKELEY,CA 94710. YONSEI UNIV,DEPT PHYS,SEOUL 120749,SOUTH KOREA. PHILIPS ANALYT XRAY,TEMPE,AZ 85283. RP Noh, M (reprint author), UNIV OREGON,INST MAT SCI,EUGENE,OR 97403, USA. RI Kevan, Stephen/F-6415-2010 OI Kevan, Stephen/0000-0002-4621-9142 NR 14 TC 5 Z9 5 U1 2 U2 6 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 JUN 15 PY 1997 VL 81 IS 12 BP 7787 EP 7792 DI 10.1063/1.365388 PG 6 WC Physics, Applied SC Physics GA XF588 UT WOS:A1997XF58800012 ER PT J AU Wilcoxon, JP Newcomer, PP Samara, GA AF Wilcoxon, JP Newcomer, PP Samara, GA TI Synthesis and optical properties of MoS2 and isomorphous nanoclusters in the quantum confinement regime SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID ELECTRONIC-STRUCTURE; SEMICONDUCTOR; WSE2 AB Highly crystalline nanoclusters of hexagonal (2H polytype) MoS2 and several of its isomorphous Mo and W chalcogenides have been synthesized with excellent control over cluster size down to similar to 2 nm. These clusters exhibit highly structured, bandlike optical absorption and photoluminescence spectra which can be understood in terms of the band-structures for the bulk crystals. Key results of this work include: (1) strong quantum confinement effects with blue shifts in some of the absorption features relative to bulk crystals as large as 4 eV for clusters similar to 2.5 nm in size, thereby allowing great tailorability of the optical properties; (2) the quasiparticle (or excitonic) nature of the optical response is preserved down to clusters less than or similar to 2.5 nm in size which are only two unit cells thick; (3) the demonstration of the strong influence of dimensionality on the magnitude of the quantum confinement. Specifically, three-dimensional confinement of the carriers produces energy shifts which are over an order of magnitude larger than those due to one-dimensional (perpendicular to the layer planes) confinement emphasizing the two-dimensional nature of the structure and bonding; (4) the observation of large increases in the spin-orbit splittings at the top of the valence band at the K and M points of the Brillouin zone with decreasing cluster size, a feature that reflects quantum confinement as well as possible changes in the degree of hybridization of the electronic orbitals which make up the states at these points; and (5) the observation of photoluminescence due to both direct and surface recombination. Several of these features bode well for the potential of these materials for solar photocatalysis. (C) 1997 American Institute of Physics. RP Wilcoxon, JP (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 17 TC 138 Z9 142 U1 5 U2 112 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 JUN 15 PY 1997 VL 81 IS 12 BP 7934 EP 7944 DI 10.1063/1.365367 PG 11 WC Physics, Applied SC Physics GA XF588 UT WOS:A1997XF58800033 ER PT J AU Seager, CH Warren, WL Tallant, DR AF Seager, CH Warren, WL Tallant, DR TI Electron-beam-induced charging of phosphors for low voltage display applications SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID INSULATORS; BOMBARDMENT AB Shifts of the surface potential were measured for several commercial phosphors by monitoring secondary and Auger electron spectra during electron beam irradiation at energies between 0.5 and 5 keV. The insulating phosphors charge strongly negative above 2 keV, whereas the conductive ones do not. This charging behavior is exaggerated after prolonged beam exposure. Measurements using two coincident electron beams to control the surface potential demonstrate that aging-enhanced surface charging decreases the phosphor cathodoluminescence. The dependence of the phosphor surface potential on the voltage applied to the metal plate on which they are deposited was also determined. These data suggest the presence of substantial space charge in the phosphors, even at low electron beam energies where no beam-induced shifts of the surface potentials are seen. We suggest that the electric fields due to these near-surface space charge regions are crucial in altering secondary emission and in establishing a steady state charge balance in the case where no currents can flow from the irradiated phosphor surface to the conductive backplane. (C) 1997 American Institute of Physics. RP Seager, CH (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 16 TC 28 Z9 28 U1 0 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 JUN 15 PY 1997 VL 81 IS 12 BP 7994 EP 8001 DI 10.1063/1.365403 PG 8 WC Physics, Applied SC Physics GA XF588 UT WOS:A1997XF58800043 ER PT J AU Jungen, C Pratt, ST AF Jungen, C Pratt, ST TI Vibrational autoionization in polyatomic molecules SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID QUANTUM-DEFECT THEORY; TRIPLE-RESONANCE SPECTROSCOPY; ANGULAR-MOMENTUM STATES; EXCITED RYDBERG STATES; JET-COOLED ANILINE; THRESHOLD PHOTOIONIZATION; BRANCHING RATIOS; DIATOMIC-MOLECULES; HIGH-RESOLUTION; DIPOLE-MOMENT AB A general framework for vibrational autoionization in polyatomic molecules with nondegenerate ion cores is presented in terms of a nondiagonal quantum defect matrix. The expressions for the vibrational autoionization rate depend on two vibrational-mode-dependent factors; (1) a vibrational ''zero-point amplitude'' that describes the displacement along a given normal coordinate and (2) a quantum defect derivative that describes the effect of the vibration on the electronic degrees of freedom. The latter is closely related to the dipole moment derivative and thus to the infrared intensity of that mode. This connection provides insight into the recently observed mode dependence of the vibrational autoionization rates for NO2 and other small molecules. (C) 1997 American Institute of Physics. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. RP Jungen, C (reprint author), UNIV PARIS 11,CNRS,AIME COTTON LAB,F-91405 ORSAY,FRANCE. NR 66 TC 32 Z9 33 U1 0 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 JUN 15 PY 1997 VL 106 IS 23 BP 9529 EP 9538 DI 10.1063/1.473844 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA XE026 UT WOS:A1997XE02600013 ER PT J AU Schwegler, E Challacombe, M HeadGordon, M AF Schwegler, E Challacombe, M HeadGordon, M TI Linear scaling computation of the fock matrix .2. Rigorous bounds on exchange integrals and incremental Fock build SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ELECTRONIC-STRUCTURE CALCULATIONS; FAST MULTIPOLE METHOD; DENSITY-MATRIX; SYSTEM-SIZE; CRYSTALLINE SYSTEMS; PERIODIC-SYSTEMS; LARGE MOLECULES; SCF METHOD; ASYMPTOTICS; ALGORITHM AB A new linear scaling method for computation of the Cartesian Gaussian-based Hartree-Fock exchange matrix is described, which employs a method numerically equivalent to standard direct SCF, and which does not enforce locality of the density matrix. With a previously described method for computing the Coulomb matrix [J. Chem. Phys. 106, 5526 (1997)], linear scaling incremental Fock builds are demonstrated for the first time, Microhartree accuracy and linear scaling are achieved for restricted Hartree-Fock calculations on sequences of water clusters and polyglycine alpha-helices with the 3-21G and 6-31G basis sets. Eightfold speedups are found relative to our previous method. For systems with a small ionization potential, such as graphitic sheets, the method naturally reverts to the expected quadratic behavior. Also, benchmark 3-21G calculations attaining microhartree accuracy are reported for the P53 tetramerization monomer involving 698 atoms and 3836 basis functions. (C) 1997 American Institute of Physics. C1 UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. UNIV MINNESOTA,MINNESOTA SUPERCOMP INST,MINNEAPOLIS,MN 55415. RP Schwegler, E (reprint author), UNIV MINNESOTA,DEPT CHEM,MINNEAPOLIS,MN 55455, USA. RI Schwegler, Eric/F-7294-2010; Schwegler, Eric/A-2436-2016 OI Schwegler, Eric/0000-0003-3635-7418 NR 55 TC 154 Z9 154 U1 2 U2 22 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 JUN 15 PY 1997 VL 106 IS 23 BP 9708 EP 9717 DI 10.1063/1.473833 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA XE026 UT WOS:A1997XE02600032 ER PT J AU Wasserman, E Rustad, JR Xantheas, SS AF Wasserman, E Rustad, JR Xantheas, SS TI Interaction potential of Al3+ in water from first principles calculations SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID CORRELATED MOLECULAR CALCULATIONS; GAUSSIAN-BASIS SETS; N = 1-4; AQUEOUS-SOLUTION; ALUMINUM SPECIATION; ELECTRONEGATIVITY EQUALIZATION; GIBBSITE SOLUBILITY; DYNAMICS SIMULATION; POLARIZABLE WATER; BINDING-ENERGIES AB We present a parametrization of the interaction potential for Al3+ in water from first principles calculations. We have performed a critical study of the Al3+-water interaction using sequences of correlation consistent basis sets that approach the complete basis set limit and include core-valence correlation effects. We suggest as minimum theoretical requirements treatment of the electron correlation at the MP2 level of theory using a triple zeta quality basis set that accounts for the effect of core-valence correlation. The latter amounts for an increase of similar to 5 kcal/mol (3%) to the stabilization energy, a shortening of 0.015 Angstrom in the Al-O distance, and an increase of 22 cm(-1) in the harmonic frequency of the Al-O vibration. This is the first time that core-valence effects were investigated for this system. The stabilization energy of the Al3+(H2O) cluster is 201 kcal/mol and the corresponding Al-O bond length is 1.719 Angstrom at the MP2 level of theory with the cc-pwCVQZ basis set. This minimum is metastable with respect to the Al2+ + H2O+ asymptote since even the second ionization potential (IF) of Al is larger than the first IP of water. The hexa-aqua cluster Al3+(H2O)(6) is, however, stable upon dissociation to Al3+(H2O)(5) + H2O by 64.8 kcal/mol, demonstrating the capacity of ''effective'' solvation in stabilizing the charge on the cation. The optimal structures of the n = 5 and 6 clusters (having C-2v and T-h symmetries, respectively) and their harmonic vibrational frequencies are the first ones reported at the MP2 level with basis sets of this size. Core-valence correlation effects for the n = 6 cluster are found to be of similar magnitude with those observed for the n = 1 cluster. The stabilization energy of the n = 6 cluster with respect to its fragments is 723.7 kcal/mol and the corresponding Al-O distance is 1.911 Angstrom. These results were used in order to parametrize a pairwise-additive interaction potential for aluminum-water interaction that was grafted onto the Toukan-Rahman interaction potential for water. The potential model reproduces the nb initio results for Al3+(H2O)6 within 2.0 kcal/mol for the stabilization energy and 0.003 Angstrom for R(Al-O) distance. Using this potential we estimated the enthalpy of solvation of Al3+ to be -1106i6 kcal/mol, therefore favoring the lower value of the experimentally obtained data (-1115 and -1140 kcal/mol, respectively). In addition, we calculate the first peak of the Al-O radial distribution function at 1.885 Angstrom, in excellent agreement with x-ray diffraction studies that suggest a peak at 1.882-0.004 Angstrom. We compute the first peak of the Al-H radial distribution function at 2.473 Angstrom and the average angle between the plane of a water molecule and the Al-O vector at -28.27 degrees. (C) 1997 American Institute of Physics. RP Wasserman, E (reprint author), PACIFIC NW LAB, ENVIRONM MOL SCI LAB, POB 999, RICHLAND, WA 99352 USA. RI Xantheas, Sotiris/L-1239-2015 NR 88 TC 69 Z9 70 U1 3 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 JUN 15 PY 1997 VL 106 IS 23 BP 9769 EP 9780 DI 10.1063/1.473866 PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA XE026 UT WOS:A1997XE02600038 ER PT J AU Koretsky, GM Knickelbein, MB AF Koretsky, GM Knickelbein, MB TI Photoionization studies of manganese clusters: Ionization potentials for Mn-7 to Mn-64 SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID TRANSITION-METAL CLUSTERS; PHOTOELECTRON-SPECTROSCOPY; NIOBIUM CLUSTERS; ELECTRONIC-STRUCTURE; IRON CLUSTERS; REACTIVITY; DEPENDENCE; PARTICLES; ENERGIES; BINDING AB The photoionization spectra of manganese clusters consisting of between seven and sixty-four atoms have been measured near threshold. As for other transition metal clusters previously investigated, the ionization potentials (IPs) decrease rapidly but nonmonotonically up to n congruent to 20 and more slowly and smoothly beyond that. No correlation is observed between Mn, IPs and their reactivity toward molecular hydrogen, reported previously by Parks et al. [J. Chem. Phys. 104, 3531 (1996)]. In particular, the absence of any discontinuity in IP at Mn-16 suggests that the onset of reactivity toward hydrogen noted at that size is not due to a sudden change in electronic structure (e.g., a nonmetal-to-metal transition), but rather to a change in cluster geometry. (C) 1997 American Institute of Physics. C1 ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. NR 41 TC 37 Z9 37 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 JUN 15 PY 1997 VL 106 IS 23 BP 9810 EP 9814 DI 10.1063/1.473870 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA XE026 UT WOS:A1997XE02600042 ER PT J AU Eng, J Raghavachari, K Struck, LM Chabal, YJ Bent, BE Flynn, GW Christman, SB Chaban, EE Williams, GP Radermacher, K Manti, S AF Eng, J Raghavachari, K Struck, LM Chabal, YJ Bent, BE Flynn, GW Christman, SB Chaban, EE Williams, GP Radermacher, K Manti, S TI A vibrational study of ethanol adsorption on Si(100) SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID CHEMICAL VAPOR-DEPOSITION; LOW-PRESSURE DEPOSITION; THIN-FILM GROWTH; BOROPHOSPHOSILICATE GLASS; SURFACE; SIO2; SILICON; TETRAETHYLORTHOSILICATE; TETRAETHOXYSILANE; DECOMPOSITION AB The adsorption of ethanol-d(0), -d(3), and -d(6) on Si(100) has been studied in the mid- to far-infrared region using surface infrared absorption spectroscopy. The acquisition of infrared spectra in this frequency range ( < 1450 cm(-1)) is made possible by using specially prepared Si(100) wafers which have a buried metallic CoSi2 layer that acts as an internal mirror. We find that ethanol dissociatively adsorbs across the Si(100) dimers near room temperature to form surface bound hydrogen and ethoxy groups. Furthermore, the ethoxy groups are oriented such that the C-3 upsilon axis of the methyl group is nearly perpendicular to the surface, unlike the case for ethoxy groups bound to metal surfaces. This adsorption geometry is deduced on the basis of the surface dipole selection rule, which applies to these Si(100) samples with a buried CoSi2 layer. Ab initio cluster calculations using gradient-corrected density functional methods confirm the proposed adsorption geometry for ethoxy on Si(100) and accurately reproduce the observed normal mode frequencies; (C) 1997 American Institute of Physics. C1 AT&T BELL LABS, LUCENT TECHNOL, MURRAY HILL, NJ 07974 USA. COLUMBIA UNIV, DEPT CHEM, NEW YORK, NY 10027 USA. COLUMBIA UNIV, COLUMBIA RADIAT LAB, NEW YORK, NY 10027 USA. BROOKHAVEN NATL LAB, UPTON, NY 11973 USA. FORSCHUNGSZENTRUM JULICH, FORSCHUNGSZENTRUM, INST SCHICHT & IONENTECH, D-5170 JULICH, GERMANY. RI Chabal, Yves/A-5998-2011 OI Chabal, Yves/0000-0002-6435-0347 NR 31 TC 69 Z9 69 U1 1 U2 10 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 JUN 15 PY 1997 VL 106 IS 23 BP 9889 EP 9898 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA XE026 UT WOS:A1997XE02600050 ER PT J AU Moore, MD Schrag, DP Kashgarian, M AF Moore, MD Schrag, DP Kashgarian, M TI Coral radiocarbon constraints on the source of the Indonesian throughflow SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID BOMB RADIOCARBON; INDIAN-OCEAN; PACIFIC; C-14; VARIABILITY; CIRCULATION; THERMOCLINE; MODEL; FLOW; AMS AB Radiocarbon variability in Porites spp. corals from Guam and the Makassar Strait (Indonesian Seaway) was used to identify the source waters contributing to the Indonesian throughflow. Time series with bimonthly resolution were constructed using accelerator mass spectrometry. The seasonal variability ranges from 15 to 60 parts per thousand, with large interannual variability. Delta(14)C values from Indonesia and Guam have a nearly identical range. Annual mean Delta(14)C values from Indonesia are 50 to 60 parts per thousand higher than in corals from Canton in the South Equatorial Current [Druffel, 1987]. These observations support a year-round North Pacific source for the Indonesian throughflow and imply negligible contribution by South Equatorial Current water. The large seasonality in Delta(14)C values from both sites emphasizes the dynamic behavior of radiocarbon in the surface ocean and suggests that Delta(14)C time series of similar resolution can help constrain seasonal and interannual changes in ocean circulation in the Pacific over the last several decades. C1 LAWRENCE LIVERMORE NATL LAB,CTR ACCELERATOR MASS SPECTROMETRY,LIVERMORE,CA 94551. PRINCETON UNIV,DEPT GEOL & GEOPHYS SCI,PRINCETON,NJ 08544. RP Moore, MD (reprint author), UNIV CALIF SAN DIEGO,SCRIPPS INST OCEANOG,GEOSCI RES DIV,LA JOLLA,CA 92093, USA. RI Kashgarian, Michaele/E-1665-2011 OI Kashgarian, Michaele/0000-0001-7824-8418 NR 38 TC 26 Z9 26 U1 0 U2 11 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD JUN 15 PY 1997 VL 102 IS C6 BP 12359 EP 12365 DI 10.1029/97JC00590 PG 7 WC Oceanography SC Oceanography GA XF422 UT WOS:A1997XF42200002 ER PT J AU Cooper, LW Whitledge, TE Grebmeier, JM Weingartner, T AF Cooper, LW Whitledge, TE Grebmeier, JM Weingartner, T TI The nutrient, salinity, and stable oxygen isotope composition of Bering and Chukchi Seas waters in and near the Bering Strait SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID ARCTIC-OCEAN; FRESH-WATER; SHELF; ICE; HALOCLINE; NITROGEN; CIRCULATION; TRANSPORT; POLYNYA; MASSES AB Seawater nutrient, salinity, and oxygen 18 data collected from 1990 to 1993 in the Bering and Chukchi Seas were used to identify potential sources of nutrients and water masses that result in formation of the Arctic Ocean upper halocline and its associated nutrient maximum. Water matching the delta(18)O values of the Arctic Ocean upper halocline and containing sufficient, or a nearly sufficient, nutrient and salinity concentration was collected in subsurface waters in the summer in portions of the Bering Sea, particularly the Gulf of Anadyr. However, nutrient concentrations significantly declined in this north flowing water over the shallow continental shelf before it reached the Bering Strait, as a consequence of biological utilization, and dilution with nutrient-poor and oxygen 18-depleted fresh water. Therefore it does not appear likely that the flow of unaltered water through the Bering Strait in the summer plays a critical role in the formation of the Arctic Ocean upper halocline. The role of other mechanisms for contributing Pacific-derived waters to the Arctic Ocean nutrient maximum is considered. C1 UNIV TENNESSEE,DEPT ECOL & EVOLUTIONARY BIOL,KNOXVILLE,TN 37996. UNIV ALASKA,INST MARINE SCI,FAIRBANKS,AK 99775. UNIV TEXAS,INST MARINE SCI,AUSTIN,TX 78712. RP Cooper, LW (reprint author), OAK RIDGE NATL LAB,DIV ENVIRONM SCI,POB 2008,MS6038,OAK RIDGE,TN 37831, USA. RI Cooper, Lee/E-5251-2012; Grebmeier, Jacqueline/L-9805-2013 OI Cooper, Lee/0000-0001-7734-8388; Grebmeier, Jacqueline/0000-0001-7624-3568 NR 44 TC 100 Z9 117 U1 3 U2 18 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD JUN 15 PY 1997 VL 102 IS C6 BP 12563 EP 12573 DI 10.1029/97JC00015 PG 11 WC Oceanography SC Oceanography GA XF422 UT WOS:A1997XF42200015 ER PT J AU Wang, H Singh, RN Lowden, RA AF Wang, H Singh, RN Lowden, RA TI Thermal shock behaviour of unidirectional, 0 degrees/90 degrees, and 2-D woven fibre-reinforced CVI SiC matrix composites SO JOURNAL OF MATERIALS SCIENCE LA English DT Article ID CHEMICAL-VAPOR INFILTRATION; MECHANICAL-PROPERTIES; CERAMIC COMPOSITES; SILICON-CARBIDE; FAILURE MECHANISMS; FIBER COMPOSITES; CRACKING; DAMAGE AB The thermal shock behaviour of Nicalon(TM) fibre-reinforced chemical vapour infiltrated SiC matrix composites with three different types of fibre architecture, unidirectional, 0 degrees/90 degrees, and 2-D woven, has been studied using the water quench technique. Thermal shock induced damage was characterized by the destructive four-point flexure technique and the nondestructive technique of Young's modulus measurement by the dynamic resonance method. It was shown that the unidirectional and 0 degrees/90 degrees composites did not possess satisfactory mechanical properties or resistance to thermal shock because these fibre architectures prevented the composites from attaining high density during infiltration. Excess carbon coating was also found in the unidirectional and 0 degrees/90 degrees composites. Oxidation of this carbon coating contributed to the property degradation at high quench temperature difference. By contrast, the composite with 2-D woven fibre architecture created using the 0 degrees/30 degrees/60 degrees cloth lay-up showed superior mechanical properties and thermal shock resistance. The nondestructive technique of Young's modulus measurement by the dynamic resonance method was successfully used in detecting the thermal shock damage. C1 OAK RIDGE NATL LAB,DIV MET & CERAM,OAK RIDGE,TN 37831. RP Wang, H (reprint author), UNIV CINCINNATI,DEPT MAT SCI & ENGN,POB 210012,CINCINNATI,OH 45221, USA. NR 33 TC 15 Z9 15 U1 1 U2 4 PU CHAPMAN HALL LTD PI LONDON PA 2-6 BOUNDARY ROW, LONDON, ENGLAND SE1 8HN SN 0022-2461 J9 J MATER SCI JI J. Mater. Sci. PD JUN 15 PY 1997 VL 32 IS 12 BP 3305 EP 3313 DI 10.1023/A:1018639809971 PG 9 WC Materials Science, Multidisciplinary SC Materials Science GA XG480 UT WOS:A1997XG48000030 ER PT J AU Deevi, SC Sikka, VK Swindeman, CJ Seals, RD AF Deevi, SC Sikka, VK Swindeman, CJ Seals, RD TI Application of reaction synthesis principles to thermal spray coatings SO JOURNAL OF MATERIALS SCIENCE LA English DT Article ID COMBUSTION SYNTHESIS; TENSILE PROPERTIES; ALLOYS; MICROSTRUCTURE; COMPOSITE AB Reaction synthesis principles have been extended to plasma spraying to obtain coatings consisting of mixed oxide phases and iron aluminides. Elemental powders of iron and aluminium were fed through a d.c. plasma torch to deposit intermetallic coatings on carbon steel substrate. Carbon steel substrates were also pre-heated with a plasma flame to create an iron oxide surface on the substrate such that an exothermic thermite reaction takes place when molten splats of aluminium impinge the pre-heated substrate at sub- or supersonic velocities. A thermite reaction between iron oxide and aluminium allowed the formation of alumina, FeAl2O4, iron, and iron aluminide phases. The presence of FeAl2O4 and Al2O3 increased the surface hardnesses of the coating, and the hardnesses of the coatings are significantly higher than the hardnesses of steel substrate, and aluminium particles. X-ray analysis of the coatings, microstructural observations, and microhardness measurements suggest that plasma spraying conditions can be tailored to obtain coatings with high hardness values with in situ synthesized reinforcements (spinel and alumina) or iron aluminide phases. Aluminium-rich phases were observed in the as-deposited coatings when a mixture of aluminium and iron or aluminium and nickel were fed through the plasma gun in ratios equivalent to Fe3Al, FeAl, Ni3Al, and NiAl. In some cases, annealing allowed the formation of iron-rich or nickel-rich aluminide phases. High solidification rates of molten splats allowed very limited diffusional reactions between the splats of aluminium and iron, or aluminium and nickel because the available diffusional time for exothermic interfacial reactions is limited to a fraction of a second at best. Oxidation of part of the aluminium led to the formation of alumina in the as-deposited coatings, and therefore, a vacuum plasma spraying technique is desirable to obtain intermetallic phases. The results suggest that reactive spraying will allow deposition of coatings by utilizing the heats of reaction between the constituents, and reactive spraying will broaden the engineering applications of reaction synthesis techniques. C1 OAK RIDGE CTR MFG TECHNOL, THERMAL SPRAY TECHNOL CTR, OAK RIDGE, TN USA. PHILIP MORRIS USA, CTR RES & DEV, RICHMOND, VA 23234 USA. RP Deevi, SC (reprint author), OAK RIDGE NATL LAB, DIV MET & CERAM, OAK RIDGE, TN 37831 USA. NR 26 TC 24 Z9 25 U1 1 U2 7 PU CHAPMAN HALL LTD PI LONDON PA 2-6 BOUNDARY ROW, LONDON, ENGLAND SE1 8HN SN 0022-2461 J9 J MATER SCI JI J. Mater. Sci. PD JUN 15 PY 1997 VL 32 IS 12 BP 3315 EP 3325 DI 10.1023/A:1018691826809 PG 11 WC Materials Science, Multidisciplinary SC Materials Science GA XG480 UT WOS:A1997XG48000031 ER PT J AU Chen, JH Besser, MF Trivedi, RK Kramer, MJ Sordelet, DJ AF Chen, JH Besser, MF Trivedi, RK Kramer, MJ Sordelet, DJ TI Partial melting during formation of YBa2Cu3O7-x SO JOURNAL OF MATERIALS SCIENCE LETTERS LA English DT Article ID COMPOSITE RP Chen, JH (reprint author), IOWA STATE UNIV,US DOE,AMES LAB,AMES,IA 50011, USA. NR 5 TC 2 Z9 2 U1 0 U2 1 PU CHAPMAN HALL LTD PI LONDON PA 2-6 BOUNDARY ROW, LONDON, ENGLAND SE1 8HN SN 0261-8028 J9 J MATER SCI LETT JI J. Mater. Sci. Lett. PD JUN 15 PY 1997 VL 16 IS 12 BP 988 EP 990 DI 10.1023/A:1018537516176 PG 3 WC Materials Science, Multidisciplinary SC Materials Science GA XG479 UT WOS:A1997XG47900008 ER PT J AU Plank, JS Kim, Y Dongarra, JJ AF Plank, JS Kim, Y Dongarra, JJ TI Fault-tolerant matrix operations for networks of workstations using diskless checkpointing SO JOURNAL OF PARALLEL AND DISTRIBUTED COMPUTING LA English DT Article ID DISTRIBUTED SYSTEMS; RECOVERY AB Networks of workstations (NOWs) offer a cost-effective platform for high-performance, long-running parallel computations, However, these computations must be able to tolerate the changing and often faulty nature of NOW environments, We present high-performance implementations of several fault-tolerant algorithms for distributed scientific computing, The fault-tolerance is based on diskless checkpointing, a paradigm that uses processor redundancy rather than stable storage as the fault-tolerant medium, These algorithms are able to run on clusters of workstations that change over time due to failure, load, or availability. As long as there are at least n processors in the cluster, and failures occur singly, the computation will complete in an efficient manner, We discuss the details of how the algorithms are tuned for fault-tolerance and present the performance results on a PVM network of Sun workstations connected by a fast, switched ethernet. (C) 1997 Academic Press. C1 UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, NATL ENERGY RES SCI COMP CTR, BERKELEY, CA 94720 USA. OAK RIDGE NATL LAB, MATH SCI SECT, OAK RIDGE, TN 37821 USA. RP UNIV TENNESSEE, DEPT COMP SCI, KNOXVILLE, TN 37996 USA. RI Dongarra, Jack/E-3987-2014 NR 45 TC 27 Z9 28 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 EI 1096-0848 J9 J PARALLEL DISTR COM JI J. Parallel Distrib. Comput. PD JUN 15 PY 1997 VL 43 IS 2 BP 125 EP 138 DI 10.1006/jpdc.1997.1336 PG 14 WC Computer Science, Theory & Methods SC Computer Science GA XY108 UT WOS:A1997XY10800006 ER PT J AU Gaumann, M Trivedi, R Kurz, W AF Gaumann, M Trivedi, R Kurz, W TI Nucleation ahead of the advancing interface in directional solidification SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article; Proceedings Paper CT 9th International Conference on Rapidly Quenched and Metastable Materials CY AUG 25-30, 1996 CL BRATISLAVA, SLOVAKIA SP Off Strategy & Dev Soc Sci & Technol, European Commiss, Directorate Gen XII, AlliedSignal Inc, US, Deut Phys Gesell, Int Union Pure & Appl Phys, JOEL Ltd, Japan, Alps Elect Co Ltd, Japan, Perkin Elmer GmbH DE solidification; interface velocities; non-equilibrium effects ID RAPID SOLIDIFICATION; MICROSTRUCTURAL DEVELOPMENT; DENDRITIC GROWTH; ALLOYS; SELECTION AB During directional solidification of an alloy, it is possible to nucleate the growing phase or a new phase at or ahead of the interface. This is critical in the phase selection, in the columnar to equiaxed transition under casting, welding or rapid solidification conditions and the formation of bands in peritectic systems. Following Hunt, an appropriate theoretical model is developed to determine the conditions under which nucleation can occur in the liquid close to a moving solid-liquid interface for both, low and high interface velocities. At high growth rates, non-equilibrium effects are shown to play an important role in predicting such transitions. (C) 1997 Elsevier Science S.A. C1 IOWA STATE UNIV,US DOE,AMES LAB,AMES,IA 50011. IOWA STATE UNIV,DEPT MAT SCI & ENGN,AMES,IA 50011. RP Gaumann, M (reprint author), SWISS FED INST TECHNOL,DEPT MAT ENGN,LAUSANNE,SWITZERLAND. NR 23 TC 125 Z9 132 U1 8 U2 42 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD JUN 15 PY 1997 VL 226 BP 763 EP 769 DI 10.1016/S0921-5093(97)80081-0 PG 7 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA XJ847 UT WOS:A1997XJ84700150 ER PT J AU Dubiley, S Kirillov, E Lysov, Y Mirzabekov, A AF Dubiley, S Kirillov, E Lysov, Y Mirzabekov, A TI Fractionation, phosphorylation and ligation on oligonucleotide microchips to enhance sequencing by hybridization SO NUCLEIC ACIDS RESEARCH LA English DT Article ID DNA; ARRAYS AB Oligonucleotide microchips are manufactured by immobilizing presynthesized oligonucleotides within 0.1 x 0.1 x 0.02 mm or 1 x 1 x 0.02 mm polyacrylamide gel pads arranged on the surface of a microscope slide. The gel pads are separated from each other by hydrophobic glass spacers and serve as a kind of 'microtest tube' of 200 pl or 20 nl volume, respectively. Fractionation of single-stranded DNAs is carried out by their hybridization with chip pads containing immobilized 10mers. DNA extracted separately from each pad is transferred onto a sequencing chip and analyzed thereon. The chip, containing a set of 10mers, was enzymatically phosphorylated, then hybridized with DNA and ligated in a site-directed manner with a contiguously stacked 5mer. Several cycles of successive hybridization-ligation of the chip-bound 10mers with different contiguously stacked 5mers and hybridized with DNA were carried out to sequence DNA containing tetranucleotide repeats. Combined use of these techniques show significant promise for sequence comparison of homologous regions in different genomes and for sequence analysis of comparatively long DNA fragments or DNA containing internal repeats. C1 ARGONNE NATL LAB,CTR MECHANIST BIOL & BIOTECHNOL,ARGONNE,IL 60439. VA ENGELHARDT MOL BIOL INST,JOINT HUMAN GENOME PROGRAM,MOSCOW 117984,RUSSIA. NR 25 TC 48 Z9 49 U1 0 U2 4 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD, ENGLAND OX2 6DP SN 0305-1048 J9 NUCLEIC ACIDS RES JI Nucleic Acids Res. PD JUN 15 PY 1997 VL 25 IS 12 BP 2259 EP 2265 DI 10.1093/nar/25.12.2259 PG 7 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA XF705 UT WOS:A1997XF70500003 PM 9171075 ER PT J AU Unanyan, RG Yatsenko, LP Bergmann, K Shore, BW AF Unanyan, RG Yatsenko, LP Bergmann, K Shore, BW TI Population inversion using laser and quasistatic magnetic field pulses SO OPTICS COMMUNICATIONS LA English DT Article AB We show how, using a combination of a radiative pulse and a pulsed quasistatic magnetic field, it is possible to obtain complete population inversion between two states in a multistate system. The population transfer occurs between states of opposite parity, and does not require either careful control of pulse area nor frequency chirp. When the pulses are applied in counter-intuitive order the method is dynamically equivalent to stimulated Raman adiabatic passage (STIRAP). Complete inversion is also possible for intuitively ordered pulses, with robustness equivalent to that of STIRAP. C1 ARMENIAN NATL ACAD SCI,INST PHYS RES,ASHTARAK 378410 2,ARMENIA. UKRAINIAN ACAD SCI,INST PHYS,UA-252650 KIEV,UKRAINE. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP Unanyan, RG (reprint author), UNIV KAISERSLAUTERN,FACHBEREICH PHYS,POSTFACH 3049,D-67653 KAISERSLAUTERN,GERMANY. RI BERGMANN, KLAAS/D-5543-2011 NR 10 TC 6 Z9 6 U1 0 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0030-4018 J9 OPT COMMUN JI Opt. Commun. PD JUN 15 PY 1997 VL 139 IS 1-3 BP 43 EP 47 DI 10.1016/S0030-4018(97)00098-9 PG 5 WC Optics SC Optics GA XB731 UT WOS:A1997XB73100009 ER PT J AU Unanyan, RG Yatsenko, LP Bergmann, K Shore, BW AF Unanyan, RG Yatsenko, LP Bergmann, K Shore, BW TI Laser-induced adiabatic atomic reorientation with control of diabatic losses SO OPTICS COMMUNICATIONS LA English DT Article ID COHERENT POPULATION TRANSFER; MULTILEVEL SYSTEMS; MAGNETIC SUBLEVELS; PULSES AB We discuss theoretical procedures for using a single laser pulse, of varying linear polarization, to transfer population between sublevels of a degenerate atomic level. The method is based on application of the procedure of stimulated Raman adiabatic passage (STIRAP). We also show how, in principle, a pulsed quasistatic magnetic field can be used to improve the usual adiabatic constraints on achieving complete population transfer by means of STIRAP. The technique allows use of shorter pulses, so that population transfer can be achieved more rapidly. It diminishes, or even eliminates, diabatic loss during the population transfer. C1 ARMENIAN NATL ACAD SCI,INST PHYS RES,ASHTARAK 378410 2,ARMENIA. UKRAINIAN ACAD SCI,INST PHYS,UA-252650 KIEV,UKRAINE. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP Unanyan, RG (reprint author), UNIV KAISERSLAUTERN,FACHBEREICH PHYS,POSTFACH 3049,D-67653 KAISERSLAUTERN,GERMANY. RI BERGMANN, KLAAS/D-5543-2011 NR 25 TC 53 Z9 54 U1 0 U2 12 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0030-4018 J9 OPT COMMUN JI Opt. Commun. PD JUN 15 PY 1997 VL 139 IS 1-3 BP 48 EP 54 DI 10.1016/S0030-4018(97)00099-0 PG 7 WC Optics SC Optics GA XB731 UT WOS:A1997XB73100010 ER PT J AU Roder, H Silver, RN Drabold, DA Dong, JJ AF Roder, H Silver, RN Drabold, DA Dong, JJ TI Kernel polynomial method for a nonorthogonal electronic-structure calculation of amorphous diamond SO PHYSICAL REVIEW B LA English DT Article ID MOLECULAR-DYNAMICS; SYSTEMS; STATES; MODEL AB The Kernel polynomial method (KPM) has been successfully applied to tight-binding electronic-structure calculations as an O(N) method. Here we extend this method to nonorthogonal basis sets with a sparse overlap matrix S and a sparse Hamiltonian H. Since the KPM method utilizes matrix vector multiplications it is necessary to apply S-1H onto a vector. The multiplication of S-1 is performed using a preconditioned conjugate-gradient method and does not involve the explicit inversion of S. Hence the method scales the same way as the original KPM method, i.e., O(N), although there is an overhead due to the additional conjugate-gradient part. We apply this method to a large scale electronic-structure calculation of amorphous diamond. C1 OHIO UNIV,DEPT PHYS & ASTRON,CONDENSED MATTER & SURFACE SCI PROGRAM,ATHENS,OH 45701. RP Roder, H (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. RI Dong, Jianjun/F-5832-2010; OI Drabold, David/0000-0001-5344-5837 NR 18 TC 15 Z9 15 U1 0 U2 0 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 JUN 15 PY 1997 VL 55 IS 23 BP 15382 EP 15385 DI 10.1103/PhysRevB.55.15382 PG 4 WC Physics, Condensed Matter SC Physics GA XH335 UT WOS:A1997XH33500011 ER PT J AU Han, DX Wang, KD Yeh, CN Yang, LY Deng, XM VonRoedern, B AF Han, DX Wang, KD Yeh, CN Yang, LY Deng, XM VonRoedern, B TI Luminescence in amorphous silicon p-i-n diodes under double-injection dispersive-transport-controlled recombination SO PHYSICAL REVIEW B LA English DT Article ID A-SI-H; TEMPERATURE-DEPENDENCE; PHOTO-LUMINESCENCE; ELECTROLUMINESCENCE; PHOTOLUMINESCENCE; ALLOYS AB The temperature and electric-field dependence of the forward bias current and the electroluminescence (EL) in hydrogenated amorphous silicon (a-Si:H) p-i-n and n-i-p diodes have been studied. Both the current and the EL efficiency temperature dependence show three regions depending on either hopping-controlled or multiple-trapping or ballistic transport mechanisms. Comparing the thermalization-controlled geminate recombination processes of photoluminescence to the features of EL, the differences can be explained by transport-controlled nongeminate recombination in trap-rich materials. C1 SOLAREX CORP,AMOCO ENRON SOLAR,SOLAREX BUSINESS UNIT A,NEWTOWN,PA 18940. ENERGY CONVERS DEVICES INC,TROY,MI 48084. NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401. RP Han, DX (reprint author), UNIV N CAROLINA,DEPT PHYS & ASTRON,CHAPEL HILL,NC 27599, USA. NR 35 TC 7 Z9 8 U1 1 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 JUN 15 PY 1997 VL 55 IS 23 BP 15619 EP 15630 DI 10.1103/PhysRevB.55.15619 PG 12 WC Physics, Condensed Matter SC Physics GA XH335 UT WOS:A1997XH33500055 ER PT J AU Bolton, SR BarAd, S Sucha, G Chemla, DS Sivco, DL Cho, AY AF Bolton, SR BarAd, S Sucha, G Chemla, DS Sivco, DL Cho, AY TI Effect of confinement on energy-dependent dephasing in heterostructures SO PHYSICAL REVIEW B LA English DT Article ID QUANTUM-WELL STRUCTURES; FREE-INDUCTION DECAY; EXCITONS; RELAXATION; GAAS; ABSORPTION; PULSES; SYSTEM; LIGHT AB To study the effects of confinement by quantum-well potential discontinuities on excitonic dephasing, we performed a spectrally and temporally resolved study of band-edge four wave mixing emission from a series of In1-xGaxAs quantum wells. Our measurements reveal an array of dynamics as we move from the three-dimensional to the two-dimensional limit. Spectral resolution allows us to resolve a slowly dephasing excitonic contribution in bulk In1-xGaxAs. In measurements on quantum-well samples of intermediate width, we find no change of the dephasing time as the quantum-well width becomes smaller than the bulk Bohr diameter. This indicates that the dominant dephasing mechanism in this regime is scattering by alloy disorder and interface roughness. For quantum-well widths below 200 Angstrom we observe a substantial increase of the dephasing time. Spectral resolution allows us to associate the slow dephasing in this regime with localized excitons. C1 WILLIAMS COLL,DEPT PHYS,WILLIAMSTOWN,MA 01267. IMRA ANER,ANN ARBOR,MI 48105. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV SCI MAT,BERKELEY,CA 94720. AT&T BELL LABS,LUCENT TECHNOL,MURRAY HILL,NJ 07974. RP Bolton, SR (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. NR 21 TC 0 Z9 0 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 JUN 15 PY 1997 VL 55 IS 23 BP 15768 EP 15775 DI 10.1103/PhysRevB.55.15768 PG 8 WC Physics, Condensed Matter SC Physics GA XH335 UT WOS:A1997XH33500074 ER PT J AU Glutsch, S Lefebvre, P Chemla, DS AF Glutsch, S Lefebvre, P Chemla, DS TI Optical absorption of type-II superlattices SO PHYSICAL REVIEW B LA English DT Article ID SHORT-PERIOD SUPERLATTICES; SEMICONDUCTOR SUPERLATTICES; QUANTUM-WELLS; HETEROSTRUCTURES; EXCITONS; TRANSITION; SYSTEM; STATES; FIELD AB Optical spectra of type-ii superlattices are presented, including Coulomb interaction and continuum states. We clarify the relative importance of above- and below-barrier transition. By gradually increasing the bandgap modulation, we visualize the transition from a bulk semiconductor to a type-I or type-II superlattice. We show that transitions that dominate the spectrum of a type-II superlattice are absent in the spectrum of a type-I superlattice and vice versa. The interplay of size and Landau quantization in the optical absorption is studied for both a type-I superlattice and a type-II superlattice in a perpendicular magnetic field. C1 UNIV JENA,INST FESTKORPERTHEORIE & THEORET OPT,D-07743 JENA,GERMANY. UNIV MONTPELLIER 2,ETUD SEMICOND GRP,CNRS,F-34095 MONTPELLIER,FRANCE. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. RP Glutsch, S (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. RI LEFEBVRE, Pierre/B-3225-2008 OI LEFEBVRE, Pierre/0000-0001-8513-5489 NR 23 TC 7 Z9 7 U1 0 U2 2 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 JUN 15 PY 1997 VL 55 IS 23 BP 15786 EP 15790 DI 10.1103/PhysRevB.55.15786 PG 5 WC Physics, Condensed Matter SC Physics GA XH335 UT WOS:A1997XH33500076 ER PT J AU Ashman, C Khanna, SN Liu, F Jena, P Kaplan, T Mostoller, M AF Ashman, C Khanna, SN Liu, F Jena, P Kaplan, T Mostoller, M TI (BAl12)Cs: A cluster-assembled solid SO PHYSICAL REVIEW B LA English DT Article ID C-60; PSEUDOPOTENTIALS; DENSITY; SYSTEMS AB First-principles calculations on the geometry and stability of AlnBm clusters have been carried out to examine the effect of size, composition, and electronic-shell filling on their relative stability, It is shown that although Al and B are both trivalent, a BAl12 cluster is more stable than an Al-13 by 3.4 eV. The enhanced stability is shown to arise due to the relaxation of surface strain in the Al cage when the central Al is replaced by a smaller B atom. Replacement of an additional Al by B to produce B,all, results in deformation of the icosahedral BAl12 cage and reduces the stability. The possibility of forming crystals using BAl12 and CS is examined via total-energy calculations. It is shown that a solid with icosahedral or cuboctahedral BAl12 and Cs and having the CsCl structure is metastable and could be synthesized. C1 UNIV WISCONSIN, MAT RES GRP, ERB 729, MADISON, WI 53760 USA. VIRGINIA COMMONWEALTH UNIV, DEPT PHYS, RICHMOND, VA 23284 USA. OAK RIDGE NATL LAB, DIV SOLID STATE, OAK RIDGE, TN 37831 USA. RP Ashman, C (reprint author), VIRGINIA COMMONWEALTH UNIV, DEPT PHYS, RICHMOND, VA 23284 USA. NR 20 TC 39 Z9 41 U1 0 U2 3 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 JUN 15 PY 1997 VL 55 IS 23 BP 15868 EP 15873 DI 10.1103/PhysRevB.55.15868 PG 6 WC Physics, Condensed Matter SC Physics GA XH335 UT WOS:A1997XH33500089 ER PT J AU Regan, MJ Pershan, PS Magnussen, OM Ocko, BM Deutsch, M Berman, LE AF Regan, MJ Pershan, PS Magnussen, OM Ocko, BM Deutsch, M Berman, LE TI X-ray reflectivity studies of liquid metal and alloy surfaces SO PHYSICAL REVIEW B LA English DT Article ID VAPOR INTERFACE; ALKALI-METALS; INHOMOGENEOUS LIQUID; COMPUTER-SIMULATION; FLUID INTERFACES; CAPILLARY WAVES; GALLIUM; DIFFRACTION; CRYSTALS; TENSION AB Surface-induced atomic layering at the liquid/vapor interface in liquid metals has been observed using x-ray reflectivity on sputtered clean surfaces under ultrahigh vacuum conditions. A well-defined quasi-Bragg peak is obtained for surfaces of elemental Ga and a Ga-In alloy at large wave vectors q(z) similar to 2.3-2.5 Angstrom(-1). These results are an unambiguous indication of atomic layering with an interlayer spacing d similar to 2 pi/q(2) = 2.5-2.7 Angstrom. For liquid Ga, the amplitude of the electron-density oscillations, which is significantly underestimated by existing theory and molecular simulation, decays with a characteristic length of 6 Angstrom, which is twice that of Hg. Results on the alloy show a clear enrichment of indium at the topmost surface layer, consistent with the Gibbs adsorption rule. ?The enrichment consists of a single monolayer, with subsequent layers at the bulk eutectic composition. In order to suppress mechanically excited surface waves, the measurements were performed on thin liquid metal Alms (<0.5 mm deep), which leads to a macroscopically curved surface due to the large surface tensions in liquid metals. The experimental challenges posed by measurements on curved surfaces and the techniques that were developed are discussed in detail. C1 HARVARD UNIV,DIV APPL SCI,CAMBRIDGE,MA 02138. HARVARD UNIV,DEPT PHYS,CAMBRIDGE,MA 02138. BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. BAR ILAN UNIV,DEPT PHYS,IL-52100 RAMAT GAN,ISRAEL. BROOKHAVEN NATL LAB,NATL SYNCHROTRON LIGHT SOURCE,UPTON,NY 11973. NR 51 TC 85 Z9 85 U1 2 U2 22 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 JUN 15 PY 1997 VL 55 IS 23 BP 15874 EP 15884 DI 10.1103/PhysRevB.55.15874 PG 11 WC Physics, Condensed Matter SC Physics GA XH335 UT WOS:A1997XH33500090 ER PT J AU Harrison, N Honold, MM Kartsovnik, MV Singleton, J Hannahs, ST Rickel, DG Kushch, ND AF Harrison, N Honold, MM Kartsovnik, MV Singleton, J Hannahs, ST Rickel, DG Kushch, ND TI Quantum galvanomagnetic effects in the organic metal alpha-(BEDT-TTF)(2)TlHg(SCN)(4) SO PHYSICAL REVIEW B LA English DT Article ID CONDUCTOR ALPHA-(BEDT-TTF)2KHG(SCN)4; MAGNETIC-FIELDS; BEDT-TTF; BIS(ETHYLENEDITHIO)TETRATHIAFULVALENE; (ET)2TLHG(SCN)4; CRYSTAL; SALT AB The transverse magnetoresistance and Hall effect of the organic metal alpha-(BEDT-TTF)(2)TlHg(SCN)(4) have been studied in static magnetic fields of up to 33 T applied perpendicular to the highly conducting planes. The Hall resistivity is found to exhibit strong oscillations caused by the coexistance of quasi-one-dimensional and quasi-two-dimensional states in the electronic system. In higher quality crystals, plateaulike features appear at magnetic fields above similar to 30 T, which are consistent with recent claims of the quantum Hall effect in this material. C1 UNIV OXFORD,DEPT PHYS,CLARENDON LAB,OXFORD OX1 3PU,ENGLAND. WALTHER MEISSNER INST TIEFTEMP FORSCH,D-85748 GARCHING,GERMANY. FLORIDA STATE UNIV,NATL HIGH MAGNET FIELD LAB,TALLAHASSEE,FL 32306. RUSSIAN ACAD SCI,INST SOLID STATE PHYS,CHERNOGOLOVKA 142432,RUSSIA. RP Harrison, N (reprint author), LOS ALAMOS NATL LAB,NATL HIGH MAGNET FIELD LAB,MS-E536,LOS ALAMOS,NM 87545, USA. RI Hannahs, Scott/B-1274-2008; Kartsovnik, Mark/E-3598-2013 OI Hannahs, Scott/0000-0002-5840-7714; Kartsovnik, Mark/0000-0002-3011-0169 NR 27 TC 19 Z9 19 U1 0 U2 2 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 JUN 15 PY 1997 VL 55 IS 24 BP 16005 EP 16008 PG 4 WC Physics, Condensed Matter SC Physics GA XJ271 UT WOS:A1997XJ27100008 ER PT J AU Lee, EY Narayanamurti, V Smith, DL AF Lee, EY Narayanamurti, V Smith, DL TI Monte Carlo simulations of ballistic-electron-emission-microscopy imaging and spectroscopy of buried mesoscopic structures SO PHYSICAL REVIEW B LA English DT Article ID ELASTIC-SCATTERING; BAND-STRUCTURE; TRANSPORT; INTERFACE; GAAS; FIELD AB Monte Carlo simulations of the transport of electrons injected into the Gamma valley of GaAs are performed for ballistic-electron-emission-microscopy (BEEM) imaging and spatially resolved spectroscopy of model quantum dots and quantum wires buried beneath the Au-GaAs interface. To determine the spatial resolution and the energy resolution of BEEM for such buried mesoscopic structures, the current fluxes and the electron normal wave vector distributions are obtained as a function of the depth from the Au-GaAs interface. The BEEM current cross sections and the spatially resolved BEEM spectra on and off these structures are calculated in order to study their dependence on the depth and the scanning-tunneling microscope tip-to-sample bias. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP Lee, EY (reprint author), UNIV CALIF SANTA BARBARA,DEPT ELECT & COMP ENGN,SANTA BARBARA,CA 93106, USA. NR 25 TC 13 Z9 13 U1 0 U2 2 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 JUN 15 PY 1997 VL 55 IS 24 BP 16033 EP 16036 PG 4 WC Physics, Condensed Matter SC Physics GA XJ271 UT WOS:A1997XJ27100015 ER PT J AU Desnica, UV DesnicaFrankovic, ID Ivanda, M Furic, K Haynes, TE AF Desnica, UV DesnicaFrankovic, ID Ivanda, M Furic, K Haynes, TE TI Morphology of the implantation-induced disorder in GaAs studied by Raman spectroscopy and ion channeling SO PHYSICAL REVIEW B LA English DT Article ID AMORPHOUS-SILICON; HYDROGENATED SILICON; VIBRATIONAL-STATES; DOSE-RATE; SCATTERING; DAMAGE; GLASSES; DYNAMICS; SPECTRA; ORDER AB Disorder was introduced into GaAs by implantation of Si-30(+) ions, using a very wide range of ion doses, dose rates, and implant temperatures, and studied by Raman scattering (RS) and Rutherford backscattering ion channeling (RBS). RS spectra were deconvoluted consistently and systematically into up to four components, one of them being an apparent background signal interpreted here as a boson peak. Arguments are given that this signal represents the second amorphous phase different from a continuous random network. An intercascade distance model (ICD) was postulated, which estimates the average distance, L-ICD, between implantation-induced cascades as a function of ion dose. An analogous parameter, L-RBS, was calculated from the RBS damage fraction f(RBS). From RS data the correlation length L-RS, representing the size of crystalline regions with preserved translational symmetry, was determined by fitting the LO signal within the spatial correlation model. All three L's agree nicely, proving the equivalency of the correlation length and intercascade distance. This enabled a straightforward comparison of relevant signals and a direct correlation between RS and RBS. While measure of damage in RES (f(RBS)) reflects the disordered volume fraction of the implanted layer, RS measures simultaneously the lowering of the translational symmetry (an effect that prevails at lower doses) and the fraction of disordered volume (prevailing at higher doses). A considerable difference in sensitivity between RS and RBS to particular defects enabled the differentiation of six different types of implantation-introduced disorder. C1 OAK RIDGE NATL LAB, OAK RIDGE, TN 37831 USA. RP Desnica, UV (reprint author), RUDJER BOSKOVIC INST, POB 1016, ZAGREB, CROATIA. RI Ivanda, Mile/J-3772-2012; Haynes, Tony/P-8932-2015 OI Ivanda, Mile/0000-0002-3785-8321; Haynes, Tony/0000-0003-2871-4745 NR 67 TC 25 Z9 25 U1 2 U2 10 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 JUN 15 PY 1997 VL 55 IS 24 BP 16205 EP 16216 DI 10.1103/PhysRevB.55.16205 PG 12 WC Physics, Condensed Matter SC Physics GA XJ271 UT WOS:A1997XJ27100039 ER PT J AU Young, CF Poindexter, EH Gerardi, GJ Warren, WL Keeble, DJ AF Young, CF Poindexter, EH Gerardi, GJ Warren, WL Keeble, DJ TI Electron paramagnetic resonance of conduction-band electrons in silicon SO PHYSICAL REVIEW B LA English DT Article ID SPIN-RESONANCE; DONOR AB The g value of conduction-band electrons in silicon was properly determined by using electron paramagnetic resonance; A linear empirical relationship was first found between the g values and the thermal ionization energies of several well-known group-V substitutional shallow donors in silicon. An extrapolation of,the empirical relation to zero ionization energy predicted the g value of conduction-band (CB) electrons, g(CB) = 1.9995, which is slightly but definitely different from that of conduction electrons in the donor-impurity band of degenerate n-type silicon; although both g values have been tacitly accepted to be identical for nearly four decades. The prediction was directly verified by measuring the g value of CB electrons created either by thermal emission from shallow donors in phosphorus-doped silicon at T = 125 K and by above-band-gap optical excitation in high-purity p-type silicon at T = 3.5 K; the measured g value in both experiments was precisely g(CB) = 1.9995(1). The empirical relation is still not theoretically explained. C1 WILLIAM PATERSON COLL NEW JERSEY,DEPT CHEM & PHYS,WAYNE,NJ 07758. SANDIA NATL LABS,ADV MAT LAB,ALBUQUERQUE,NM 87185. UNIV DUNDEE,CARNEGIE LAB PHYS,DUNDEE DD1 4DH,SCOTLAND. RP Young, CF (reprint author), USA,RES LAB,FT MONMOUTH,NJ 07703, USA. RI Keeble, David /C-6633-2012 OI Keeble, David /0000-0002-5378-799X NR 32 TC 45 Z9 46 U1 1 U2 7 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 JUN 15 PY 1997 VL 55 IS 24 BP 16245 EP 16248 DI 10.1103/PhysRevB.55.16245 PG 4 WC Physics, Condensed Matter SC Physics GA XJ271 UT WOS:A1997XJ27100043 ER PT J AU Luo, JS Olson, JM Zhang, Y Mascarenhas, A AF Luo, JS Olson, JM Zhang, Y Mascarenhas, A TI Near-band-gap reflectance anisotropy in ordered Ga0.5In0.5P SO PHYSICAL REVIEW B LA English DT Article ID PHOTOLUMINESCENCE-EXCITATION-SPECTROSCOPY; DIFFERENCE SPECTROSCOPY; GAINP2; GA0.52IN0.48P; ALLOYS; ELECTROREFLECTANCE; EPITAXY; GROWTH AB We present a theory that models the reflectance difference spectrum of bulk, spontaneously ordered Ga0.5In0.5P. Near the band gap E-0 this spectrum exhibits a sharp, negative feature at E-0 and a broad positive feature that peaks near E-0+Delta(S). The zero crossing between these two peaks occurs near E-0+Delta(C). For the sample studied in this paper, the spin-orbit splitting Delta(s) and the crystal-field splitting Delta(C) are 120 and 25 meV, respectively. Two previous calculations, which assume constant transition-matrix elements, were able to produce a negative peak at E-0, but not the positive feature. In this paper, the reflectance difference spectrum near the band gap is calculated using an 8-band k.p model and an explicit treatment of the momentum or k dependence of the transition-matrix elements. The new calculation produces both the negative peak at E-0 and the positive feature that peaks near E0+Delta(S). The positive feature is attributed to the strong k dependence of the matrix element anisotropy. A strong coupling, enhanced by ordering, between three valence bands is essential. A problem associated with the analytical expression for the dielectric function epsilon used in previous calculations is discussed. RP Luo, JS (reprint author), NATL RENEWABLE ENERGY LAB, GOLDEN, CO 80401 USA. NR 32 TC 9 Z9 10 U1 1 U2 2 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 JUN 15 PY 1997 VL 55 IS 24 BP 16385 EP 16389 DI 10.1103/PhysRevB.55.16385 PG 5 WC Physics, Condensed Matter SC Physics GA XJ271 UT WOS:A1997XJ27100059 ER PT J AU Yeo, YC Li, MF Chong, TC Yu, PY AF Yeo, YC Li, MF Chong, TC Yu, PY TI Theoretical study of the energy-band structure of partially CuPt-ordered Ga0.5In0.5P SO PHYSICAL REVIEW B LA English DT Article ID VAPOR-PHASE EPITAXY; LONG-RANGE-ORDER; SEMICONDUCTOR ALLOYS; OPTICAL-PROPERTIES; ELECTRONIC-STRUCTURE; GROWTH TEMPERATURE; GAP; SUPERLATTICE; DEPENDENCE; DENSITY AB We propose a model for the partially ordered Ga0.5In0.5P alloys in which the CuPt structure is always retained. A long-range order parameter is defined in terms of the cation potentials on the group-III sublattice. Using this model we studied the electronic band structure of Ga0.5In0.5P alloys as a continuous function of the order parameter using the empirical pseudopotential method. Trends in the fundamental energy gap and effective masses are obtained. We found that the anisotropy in the effective masses is enhanced by ordering. C1 UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. RP Yeo, YC (reprint author), NATL UNIV SINGAPORE,DEPT ELECT ENGN,CTR OPTOELECT,10 KENT RIDGE CRESCENT,SINGAPORE S119260,SINGAPORE. RI Yeo, Yee-Chia/J-9029-2013 NR 42 TC 7 Z9 7 U1 0 U2 0 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 JUN 15 PY 1997 VL 55 IS 24 BP 16414 EP 16419 DI 10.1103/PhysRevB.55.16414 PG 6 WC Physics, Condensed Matter SC Physics GA XJ271 UT WOS:A1997XJ27100063 ER PT J AU Kamionkowski, M Kosowsky, A Stebbins, A AF Kamionkowski, M Kosowsky, A Stebbins, A TI Statistics of cosmic microwave background polarization SO PHYSICAL REVIEW D LA English DT Article ID GRAVITATIONAL-WAVES; ANALYTIC APPROACH; RADIATION; ANISOTROPIES; FLUCTUATIONS AB We present a formalism for analyzing a full-sky temperature and polarization map of the cosmic microwave background. Temperature maps are analyzed by expanding over the set of spherical harmonics to give multipole moments of the two-point correlation function. Polarization, which is described by a second-rank tensor, can be treated analogously by expanding in the appropriate tensor spherical harmonics. We provide expressions for the complete set of temperature and polarization multipole moments for scalar and tensor metric perturbations. Four sets of multipole moments completely describe isotropic temperature and polarization correlations; for scalar metric perturbations one set is identically zero, giving the possibility of a clean determination of the vector and tensor contributions. The variance with which the multipole moments can be measured in idealized experiments is evaluated, including the effects of detector noise, sky coverage, and beam width. Finally, we construct coordinate-independent polarization two-point correlation functions, express them in terms of the multipole moments, and derive small-angle limits. C1 HARVARD SMITHSONIAN CTR ASTROPHYS,CAMBRIDGE,MA 02138. HARVARD UNIV,LYMAN LAB PHYS,DEPT PHYS,CAMBRIDGE,MA 02138. FERMILAB NATL ACCELERATOR LAB,FERMILAB ASTROPHYS CTR,NASA,BATAVIA,IL 60510. RP Kamionkowski, M (reprint author), COLUMBIA UNIV,DEPT PHYS,538 W 120TH ST,NEW YORK,NY 10027, USA. OI Kamionkowski, Marc/0000-0001-7018-2055 NR 70 TC 572 Z9 575 U1 1 U2 8 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD JUN 15 PY 1997 VL 55 IS 12 BP 7368 EP 7388 DI 10.1103/PhysRevD.55.7368 PG 21 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA XF601 UT WOS:A1997XF60100007 ER PT J AU Jaffe, AH Turner, MS AF Jaffe, AH Turner, MS TI Limits to radiative neutrino decay from SN 1987A SO PHYSICAL REVIEW D LA English DT Article ID LIFETIMES; SN-1987A; CONSTRAINTS; MASSES AB We calculate limits to the properties of massive, unstable neutrinos using data from gamma-ray detectors on the Pioneer Venus Orbiter (PVO) Spacecraft. The absence of a gamma-ray signal in the PVO detector constrains the branching ratio to photons (B gamma), mass (m(nu)), and radiative lifetime (tau(gamma)=tau/B-gamma). For low-mass (m less than or similar to T similar to 8 MeV) neutrinos decaying nu-->nu'gamma, B-gamma<3x10(-7) for m(nu)tau less than or similar to 10(6) keVsec, and B-gamma<2x10(-13)m(nu)tau/KeV sec for m(nu)tau greater than or similar to 10(6) keV sec; limits for high-mass neutrinos are somewhat weaker due to Boltzmann suppression. We also calculate limits for decays that produce gamma rays through the bremsstrahlung channel, nu-->nu'e(+)e(-)gamma. With one exception, the PVO limits are roughly comparable to those from an analysis of data from the Solar Max Mission (SMM) Satellite (which observed at higher gamma-ray energies but for a much shorter time). For neutrino mass states that are nearly degenerate, delta m(2)/m(2) < 0.1 much less than 1, our limits for the mode nu-->nu'gamma become more stringent by a factor as large as m(2)/delta m(2), because more decay photons are shifted into the PVO energy window. For this same reason, SMM cannot constrain this case. C1 UNIV CHICAGO,ENRICO FERMI INST,DEPT PHYS,CHICAGO,IL 60637. UNIV CHICAGO,ENRICO FERMI INST,DEPT ASTRON & ASTROPHYS,CHICAGO,IL 60637. FERMILAB NATL ACCELERATOR LAB,NASA,FERMILAB ASTROPHYS CTR,BATAVIA,IL 60510. RP Jaffe, AH (reprint author), UNIV CALIF BERKELEY,CTR PARTICLE ASTROPHYS,301 LECONTE HALL,BERKELEY,CA 94720, USA. RI Jaffe, Andrew/D-3526-2009 NR 15 TC 9 Z9 9 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD JUN 15 PY 1997 VL 55 IS 12 BP 7951 EP 7959 DI 10.1103/PhysRevD.55.7951 PG 9 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA XF601 UT WOS:A1997XF60100058 ER PT J AU Li, M Brooks, JA Atteridge, DG Porter, WD AF Li, M Brooks, JA Atteridge, DG Porter, WD TI Thermophysical property measurements on low alloy high strength carbon steels SO SCRIPTA MATERIALIA LA English DT Article C1 OREGON GRAD INST,DEPT MAT SCI & ENGN,PORTLAND,OR 97221. OAK RIDGE NATL LAB,PHYS PROPERTIES USER CTR,OAK RIDGE,TN 37831. RP Li, M (reprint author), SANDIA NATL LABS,LIVERMORE,CA 94551, USA. NR 5 TC 11 Z9 11 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1359-6462 J9 SCRIPTA MATER JI Scr. Mater. PD JUN 15 PY 1997 VL 36 IS 12 BP 1353 EP 1359 DI 10.1016/S1359-6462(97)00051-1 PG 7 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA XB170 UT WOS:A1997XB17000001 ER PT J AU Schlichting, I Berendzen, J AF Schlichting, I Berendzen, J TI Out of the blue: The photocycle of the photoactive yellow protein SO STRUCTURE LA English DT Article ID BACTERIUM ECTOTHIORHODOSPIRA-HALOPHILA; LINKED 4-HYDROXYCINNAMYL CHROMOPHORE; PHOTORECEPTOR; SPECTROSCOPY; ABSORBENCY; MECHANISM C1 LOS ALAMOS NATL LAB,BIOPHYS GRP,LOS ALAMOS,NM 87545. RP Schlichting, I (reprint author), MAX PLANCK INST MOL PHYSIOL,DPET PHYS BIOCHEM,RHEINLANDDAMM 201,D-44139 DORTMUND,GERMANY. RI Schlichting, Ilme/I-1339-2013 NR 24 TC 11 Z9 11 U1 0 U2 0 PU CURRENT BIOLOGY LTD PI LONDON PA 34-42 CLEVELAND STREET, LONDON, ENGLAND W1P 6LB SN 0969-2126 J9 STRUCTURE JI Structure PD JUN 15 PY 1997 VL 5 IS 6 BP 735 EP 739 DI 10.1016/S0969-2126(97)00228-1 PG 5 WC Biochemistry & Molecular Biology; Biophysics; Cell Biology SC Biochemistry & Molecular Biology; Biophysics; Cell Biology GA XJ909 UT WOS:A1997XJ90900002 PM 9261074 ER PT J AU Lima, CD DAmico, KL Naday, I Rosenbaum, G Westbrook, EM Hendrickson, WA AF Lima, CD DAmico, KL Naday, I Rosenbaum, G Westbrook, EM Hendrickson, WA TI MAD analysis of FHIT, a putative human tumor suppressor from the HIT protein family SO STRUCTURE LA English DT Article DE advanced photon source; HIT protein family; PKCI; tumor suppressor; X-ray crystallography ID KINASE-C INHIBITOR-1; 3-DIMENSIONAL STRUCTURE; ANOMALOUS DIFFRACTION; ESCHERICHIA-COLI; RAT-LIVER; FRUCTOSE-2,6-BISPHOSPHATASE; IDENTIFICATION; SITE AB Background: The fragile histidine triad (FHIT) protein is a member of the large and ubiquitous histidine triad (HIT) family of proteins, It is expressed from a gene located at a fragile site on human chromosome 3, which is commonly disrupted in association with certain cancers, On the basis of the genetic evidence, it has been postulated that the FHIT protein may function as a tumor suppressor, implying a role for the FHIT protein in carcinogenesis. The FHIT protein has dinucleoside polyphosphate hydrolase activity in vitro, thus suggesting that its role in vivo may involve the hydrolysis of a phosphoanhydride bond, The structural analysis of FHIT will identify critical residues involved in substrate binding and catalysis, and will provide insights into the in vivo function of HIT proteins. Results: The three-dimensional crystal structures of free and nucleoside complexed FHIT have been determined from multiwavelength anomalous diffraction (MAD) data, and they represent some of the first successful structures to be measured with undulator radiation at the Advanced Photon Source. The structures of FHIT reveal that this protein exists as an intimate homodimer, which is based on a core structure observed previously in another human HIT homolog, protein kinase C interacting protein (PKCI), but has distinctive elaborations at both the N and C termini. Conserved residues within the HIT family, which are involved in the interactions of the proteins with nucleoside and phosphate groups, appear to be relevant for the catalytic activity of this protein. Conclusions: The structure of FHIT, a divergent HIT protein family member, in complex with a nucleotide analog suggests a metal-independent catalytic mechanism for the HIT family of proteins. A structural comparison of FHIT with PKCI and galactose-1-phosphate uridylyltransferase (GalT) reveals additional implications for the structural and functional evolution of the ubiquitous HIT family of proteins. C1 COLUMBIA UNIV,DEPT BIOCHEM & MOL BIOPHYS,NEW YORK,NY 10032. ARGONNE NATL LAB,STRUCT BIOL CTR,ARGONNE,IL 60439. ARGONNE NATL LAB,ELECT & COMP TECHNOL DIV,ARGONNE,IL 60439. COLUMBIA UNIV,HOWARD HUGHES MED INST,NEW YORK,NY 10032. OI Lima, Christopher/0000-0002-9163-6092 FU NIGMS NIH HHS [GM34102] NR 57 TC 50 Z9 54 U1 0 U2 1 PU CURRENT BIOLOGY LTD PI LONDON PA 34-42 CLEVELAND STREET, LONDON, ENGLAND W1P 6LB SN 0969-2126 J9 STRUCTURE JI Structure PD JUN 15 PY 1997 VL 5 IS 6 BP 763 EP 774 DI 10.1016/S0969-2126(97)00231-1 PG 12 WC Biochemistry & Molecular Biology; Biophysics; Cell Biology SC Biochemistry & Molecular Biology; Biophysics; Cell Biology GA XJ909 UT WOS:A1997XJ90900005 PM 9261067 ER PT J AU Anderson, IM Bentley, J Carter, CB AF Anderson, IM Bentley, J Carter, CB TI Secondary fluorescence correction formulae for X-ray microanalysis .1. Parallel-sided thin foil, wedge, and bulk specimens SO ULTRAMICROSCOPY LA English DT Article DE X-ray microanalysis AB Secondary fluorescence correction formulae have been derived for specimen geometries that are commonly employed in the analytical electron microscope. Formulae have been derived for parallel-sided thin foil and bulk (electron probe microanalysis) specimens, for which established correction formulae currently exist, and for wedge-shaped specimens, for which no formulae have been available to date. All derivations explicitly account for the absorption of fluoresced X-rays leaving the specimen en route to the spectrometer, which the existing correction formulae neglected wholly or in part. It is shown that the existing secondary fluorescence correction formula of Nockolds et al. for parallel-sided thin foils, which entirely neglects the absorption of secondary X-rays, is sufficiently accurate as long as the ''sec alpha'' factor is omitted. An additional factor (y/(x + y) in Reed's notation) should be appended to the existing secondary fluorescence correction formula for bulk specimens in the electron probe microanalyzer to account for near-surface absorption of fluoresced X-rays, which was neglected by Castaing. The difference in the secondary fluorescence corrections calculated with the phi/(rho z) dependencies of Lenard (exponential) and Packwood and Brown (modified Gaussian) is shown to be negligible. C1 UNIV MINNESOTA,DEPT CHEM ENGN & MAT SCI,MINNEAPOLIS,MN 55455. RP Anderson, IM (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,POB 2008,MS-6376,OAK RIDGE,TN 37831, USA. RI Carter, C. Barry/E-6478-2010 OI Carter, C. Barry/0000-0003-4251-9102 NR 26 TC 3 Z9 3 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3991 J9 ULTRAMICROSCOPY JI Ultramicroscopy PD JUN 15 PY 1997 VL 68 IS 2 BP 77 EP 94 DI 10.1016/S0304-3991(97)00015-6 PG 18 WC Microscopy SC Microscopy GA XJ577 UT WOS:A1997XJ57700001 ER PT J AU Anderson, IM Bentley, J Carter, CB AF Anderson, IM Bentley, J Carter, CB TI Secondary fluorescence correction formulae for X-ray microanalysis .2. Self-supporting discs SO ULTRAMICROSCOPY LA English DT Article DE X-ray microanalysis AB Geometric factors are derived for correction of secondary fluorescence from self-supporting thinned discs. Fluorescence is considered both when the entire 3 mm disc is exposed to the X-ray detector and when the majority of the specimen is masked by an X-ray opaque washer with a small circular aperture. Geometric factors can be expressed as a ratio of the lengths that characterize fluorescence from these discs. The geometric factors seldom exceed a few percent because self-supporting discs subtend small fractional solid angles from the perspective of the thin edge being analyzed. However, elements composing the disc are fluoresced with equal efficiency by all primary X-rays of energy higher than the ionization energy of the fluoresced element. Fluorescence of self-supporting discs is therefore qualitatively different from fluorescence of parallel-sided thin foils, wedges, and bulk specimens, for which substantial fluorescence occurs only when the energy of the fluorescing primary X-ray barely exceeds the ionization energy of the fluoresced element. C1 UNIV MINNESOTA,DEPT CHEM ENGN & MAT SCI,MINNEAPOLIS,MN 55455. RP Anderson, IM (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,POB 2008,MS-6376,OAK RIDGE,TN 37831, USA. RI Carter, C. Barry/E-6478-2010 OI Carter, C. Barry/0000-0003-4251-9102 NR 5 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3991 J9 ULTRAMICROSCOPY JI Ultramicroscopy PD JUN 15 PY 1997 VL 68 IS 2 BP 95 EP 107 DI 10.1016/S0304-3991(97)00016-8 PG 13 WC Microscopy SC Microscopy GA XJ577 UT WOS:A1997XJ57700002 ER PT J AU Hon, WC McKay, GA Thompson, PR Sweet, RM Yang, DSC Wright, GD Berghuis, AM AF Hon, WC McKay, GA Thompson, PR Sweet, RM Yang, DSC Wright, GD Berghuis, AM TI Structure of an enzyme required for aminoglycoside antibiotic resistance reveals homology to eukaryotic protein kinases SO CELL LA English DT Article ID FREE R-VALUE; BETA-LACTAMASE; KANAMYCIN NUCLEOTIDYLTRANSFERASE; SUBSTRATE-SPECIFICITY; MODIFYING ENZYMES; CRYSTAL-STRUCTURE; CATALYTIC DOMAIN; RESOLUTION; BINDING; ANALOG AB Bacterial resistance to aminoglycoside antibiotics is almost exclusively accomplished through either phosphorylation, adenylylation, or acetylation of the antibacterial agent. The aminoglycoside kinase, APH(3')IIIa, catalyzes the phosphorylation of a broad spectrum of aminoglycoside antibiotics. The crystal structure of this enzyme complexed with ADP was determined at 2.2 Angstrom resolution. The three-dimensional fold of APH(3')-IIIa reveals a striking similarity to eukaryotic protein kinases despite a virtually complete lack of sequence homology. Nearly half of the APH(3')-IIIa sequence adopts a conformation identical to that seen in these kinases. Substantial differences are found in the location and conformation of residues presumably responsible for second-substrate specificity. These results indicate that APH(3') enzymes and eukaryotic-type protein kinases share a common ancestor. C1 BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 11973. RP Hon, WC (reprint author), MCMASTER UNIV,DEPT BIOCHEM,1200 MAIN ST W,HAMILTON,ON L8N 3Z5,CANADA. RI Berghuis, Albert/A-6495-2008; OI Wright, Gerard/0000-0002-9129-7131 NR 59 TC 172 Z9 180 U1 0 U2 7 PU CELL PRESS PI CAMBRIDGE PA 1050 MASSACHUSETTES AVE, CIRCULATION DEPT, CAMBRIDGE, MA 02138 SN 0092-8674 J9 CELL JI Cell PD JUN 13 PY 1997 VL 89 IS 6 BP 887 EP 895 DI 10.1016/S0092-8674(00)80274-3 PG 9 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA XE357 UT WOS:A1997XE35700009 PM 9200607 ER PT J AU Bennett, BJ Mohandas, N Coppel, RL AF Bennett, BJ Mohandas, N Coppel, RL TI Defining the minimal domain of the Plasmodium falciparum protein MESA involved in the interaction with the red cell membrane skeletal protein 4.1 SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID ERYTHROCYTE SURFACE-ANTIGEN; INFECTED ERYTHROCYTES; BLOOD-CELL; MALARIA PARASITES; BINDING DOMAIN; SPECTRIN; CYTOADHERENCE; ASSOCIATION; MODULATION; BAND-4.1 AB During part of its life cycle, the protozoan parasite Plasmodium falciparum lives within the human red blood cell and modifies both the structural and functional properties of the red cell. It does this by synthesizing a number of polypeptides that it transports into the red cell cytoplasm and to the red cell membrane. One of these transported proteins, MESA (mature parasite-infected erythrocyte Surface antigen), is anchored to the red cell membrane by noncovalent interaction with erythrocyte protein 4.1. We have utilized a combination of in vitro transcription and translation and a membrane binding assay to identify the protein sequence involved in anchoring MESA to the membrane. Labeled fragments of different regions of the MESA protein were evaluated for their ability to bind to inside-out vesicle membrane preparations of human red cells. Binding was dependent on the presence of red cell membrane proteins and was abolished either by trypsin treatment or by selective depletion of membrane proteins. Binding was specific and could be inhibited by the addition of competing protein, with an IC,, of (6.3 +/- 1.2) x 10(-7) M, indicative of a moderate affinity interaction. Fractionation studies demonstrated that binding fragments interacted most efficiently with membrane protein fractions that had been enriched in protein 4.1. Binding inhibition experiments using synthetic peptides identified the binding domain of MESA for protein 4.1 as a 19-residue sequence near the amino terminus of MESA, a region capable of forming an amphipathic helix. C1 MONASH UNIV,DEPT MICROBIOL,CLAYTON,VIC 3168,AUSTRALIA. WALTER & ELIZA HALL INST MED RES,PARKVILLE,VIC 3050,AUSTRALIA. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV LIFE SCI,BERKELEY,CA 94720. MONASH UNIV,DEPT MICROBIOL,CLAYTON,VIC 3168,AUSTRALIA. RI Coppel, Ross/A-6626-2008 OI Coppel, Ross/0000-0002-4476-9124 FU NIDDK NIH HHS [DK32094-10] NR 54 TC 38 Z9 38 U1 0 U2 3 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 JUN 13 PY 1997 VL 272 IS 24 BP 15299 EP 15306 DI 10.1074/jbc.272.24.15299 PG 8 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA XE034 UT WOS:A1997XE03400040 PM 9182557 ER PT J AU David, NE Gee, M Andersen, B Naider, F Thorner, J Stevens, RC AF David, NE Gee, M Andersen, B Naider, F Thorner, J Stevens, RC TI Expression and purification of the Saccharomyces cerevisiae alpha-factor receptor (Ste2p), a 7-transmembrane-segment G protein-coupled receptor SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID INFECTED INSECT CELLS; PHEROMONE RESPONSE PATHWAY; DOPAMINE D-2 RECEPTOR; ESCHERICHIA-COLI; BINDING PROTEIN; GENE-EXPRESSION; YEAST; SUBUNIT; ACETYLCHOLINE; MUTANTS AB A plasmid vector was developed that permitted high-level expression of a functional form of the Saccharomyces cerevisiae alpha-factor receptor (the STE2 gene product) tagged at its C-terminal end with an epitope (FLAG) and a His(6) tract. When expressed in yeast from this plasmid, Ste2p was produced at a level at least S-fold higher than that reported previously for any other 7-transmembrane-segment receptor expressed in the same cells. For purification, isolated cell membranes containing the overexpressed receptor were solubilized with detergent under specific conditions and subjected to immobilized metal affinity chromatography. Yields as high as 1 mg of nearly homogeneous (95%) receptor were routinely obtained even from relatively small scale preparations (60 g of frozen cell paste). The purified receptor was :reconstituted into artificial phospholipid vesicles. Radioligand binding studies demonstrated that the purified receptor, in the reconstituted vesicles, bound its tridecapeptide ligand (alpha-factor) with a K-D (155 nM) consistent with the affinity expected for this receptor in the absence of its associated G protein. Efficient restoration of ligand binding activity upon reconstitution required the addition of solubilized membranes prepared from a yeast strain lacking the receptor. Sufficient amounts of active material can be obtained by this procedure to allow physical studies of this receptor and other 7-transmembrane-segment receptors expressed in this system. C1 UNIV CALIF BERKELEY, DEPT CHEM, BERKELEY, CA 94720 USA. UNIV CALIF BERKELEY, DEPT CELL & MOL BIOL, BERKELEY, CA 94720 USA. ROYAL VET & AGR UNIV, DEPT PLANT BIOL, DK-1871 FREDERIKSBERG C, DENMARK. UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, DONNER LAB, DIV LIFE SCI, BERKELEY, CA 94720 USA. CUNY COLL STATEN ISL, DEPT CHEM, STATEN ISL, NY 10314 USA. RI Stevens, Raymond/K-7272-2015 OI Stevens, Raymond/0000-0002-4522-8725 FU NIGMS NIH HHS [GM07232, GM22086, GM22087] NR 42 TC 72 Z9 73 U1 0 U2 1 PU AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3996 USA SN 0021-9258 EI 1083-351X J9 J BIOL CHEM JI J. Biol. Chem. PD JUN 13 PY 1997 VL 272 IS 24 BP 15553 EP 15561 DI 10.1074/jbc.272.24.15553 PG 9 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA XE034 UT WOS:A1997XE03400075 PM 9182592 ER PT J AU Wedemayer, GJ Patten, PA Wang, LH Schultz, PG Stevens, RC AF Wedemayer, GJ Patten, PA Wang, LH Schultz, PG Stevens, RC TI Structural insights into the evolution of an antibody combining site SO SCIENCE LA English DT Article ID ESCHERICHIA-COLI; CATALYTIC ANTIBODIES; ANTIGEN INTERACTIONS; DIVERSITY; BINDING; RECOGNITION; GENERATION; EXPRESSION; FRAGMENTS; SEGMENTS AB The crystal structures of a germline antibody Fab fragment and its complex with hapten have been solved at 2.1 Angstrom resolution. These structures are compared with the corresponding crystal structures of the affinity-matured antibody, 48G7, which has a 30,000 times higher affinity for hapten as a result of nine replacement somatic mutations. Significant changes in the configuration of the combining site occur upon binding of hapten to the germline antibody, whereas hapten binds to the mature antibody by a lock-and-key fit mechanism. The reorganization of the combining site that was nucleated by hapten binding is further optimized by somatic mutations that occur up to 15 Angstrom from bound hapten. These results suggest that the binding potential of the primary antibody repertoire may be significantly expanded by the ability of germline antibodies to adopt more than one combining-site configuration, with both antigen binding and somatic mutation stabilizing the configuration with optimal hapten complementarity. C1 UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. UNIV CALIF LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. HOWARD HUGHES MED INST,SEATTLE,WA. RI Stevens, Raymond/K-7272-2015 OI Stevens, Raymond/0000-0002-4522-8725 FU NIAID NIH HHS [R01 AI39089] NR 56 TC 392 Z9 397 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 JUN 13 PY 1997 VL 276 IS 5319 BP 1665 EP 1669 DI 10.1126/science.276.5319.1665 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA XD947 UT WOS:A1997XD94700032 PM 9180069 ER PT J AU Greenblatt, BJ Zanni, MT Neumark, DM AF Greenblatt, BJ Zanni, MT Neumark, DM TI Photodissociation of I-2(-)(Ar)(n) clusters studied with anion femtosecond photoelectron spectroscopy SO SCIENCE LA English DT Article ID DYNAMICS; RECOMBINATION AB Anion femtosecond photoelectron spectroscopy was used to follow the dynamics of the I-2(-)(Ar)(6) and I-2(-)(Ar)(20) clusters subsequent to photodissociation of the I-2(-) chromophore. The experiments showed that photodissociation of the I-2(-) moiety in I-2(-)(Ar)(6) is complete by approximately 200 femtoseconds, just as in bare I-2(-), but also that attractive interactions between the departing anion fragment and the solvent atoms persisted for 1200 femtoseconds. Photodissociation of I-2(-)(Ar)(20) results in caging of the I-2(-) followed by recombination and vibrational relaxation on the excited (A) over tilde (2) Pi(g,3/2) and the ground (X) over tilde 2 Sigma(u)(+) states; these processes are complete in 35 and 200 picoseconds, respectively. C1 UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. RI Zanni, Martin/K-2707-2013; Neumark, Daniel/B-9551-2009 OI Neumark, Daniel/0000-0002-3762-9473 NR 22 TC 125 Z9 126 U1 0 U2 11 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD JUN 13 PY 1997 VL 276 IS 5319 BP 1675 EP 1678 DI 10.1126/science.276.5319.1675 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA XD947 UT WOS:A1997XD94700035 ER PT J AU Andersen, KB Abildgaard, J Radziszewski, JG SpangetLarsen, J AF Andersen, KB Abildgaard, J Radziszewski, JG SpangetLarsen, J TI Molecular and vibrational structure of 1,6,6a lambda(4)-trithiapentalene. Infrared linear dichroism spectroscopy and ab initio normal-mode analyses SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID STRETCHED POLYETHYLENE; ENERGY AB The vibrational structure of the title compound (TTP) was studied by experimental and theoretical methods. IR absorption spectra were recorded in argon matrix and in stretched polyethylene at 12 K. The linear dichroism (LD) observed in the latter solvent provided experimental symmetry assignments of the observed vibrational states. Molecular geometries and harmonic force fields were calculated ab initio with the 6-311G** basis set using three different procedures: restricted Hartree-Fock theory (HF), second-order Moller-Plesset perturbation theory (MP2), and density functional theory (DFT). In the latter, Becke's gradient-corrected exchange functional was combined with Perdew and Wang's correlation functional (BPW91), leading to excellent agreement with observed IR transitions. The combined experimental and theoretical evidence enabled an essentially complete assignment of the fundamental vibrations. Of particular importance is the assignment for the first time of the long-sought ''bell-clapper'' mode associated with the unique S-S-S structural element of TTP, giving rise to an intense, long-axis polarized transition in the far-IR (153 cm(-1)). C1 NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401. ROSKILDE UNIV CTR,DEPT LIFE SCI & CHEM,DK-4000 ROSKILDE,DENMARK. NR 30 TC 16 Z9 16 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD JUN 12 PY 1997 VL 101 IS 24 BP 4475 EP 4480 DI 10.1021/jp970777n PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA XD906 UT WOS:A1997XD90600023 ER PT J AU Lio, A Morant, C Ogletree, DF Salmeron, M AF Lio, A Morant, C Ogletree, DF Salmeron, M TI Atomic force microscopy study of the pressure-dependent structural and frictional properties of n-alkanethiols on gold SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID SELF-ASSEMBLED MONOLAYERS; SUPERLATTICE STRUCTURE; SCALE FRICTION; AU(111); SURFACE; FILMS; DIFFRACTION; CANTILEVERS; DISULFIDES; MICA AB Atomic force microscopy (AFM) has been used to study the effect of pressure on the structural and frictional properties of self-assembled monolayers of n-octadecanethiol on Au(111). Sharp microfabricated silicon nitride tips (tip radii 100-300 Angstrom) were used. At low load, the periodicity of the thiol layer is imaged. At higher load, the layer is observed to become disordered. At a critical contact pressure of similar to 2.3 GPa, a transition from the thiol overlayer to the Au(111) substrate periodicity is observed in the lattice resolution images. This transition is gradual and reversible. During the transition, frictional forces first increase and then decrease as the tip-sample separation decreases by a distance approximately equivalent to the thickness of the thiol layer. C1 UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, DIV MAT SCI, BERKELEY, CA 94720 USA. UNIV GLASGOW, DEPT ELECT, GLASGOW G12 8QQ, LANARK, SCOTLAND. UNIV AUTONOMA MADRID, FAC CIENCIAS, E-28049 MADRID, SPAIN. NR 41 TC 92 Z9 92 U1 0 U2 12 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1520-6106 J9 J PHYS CHEM B JI J. Phys. Chem. B PD JUN 12 PY 1997 VL 101 IS 24 BP 4767 EP 4773 DI 10.1021/jp963807f PG 7 WC Chemistry, Physical SC Chemistry GA XD908 UT WOS:A1997XD90800009 ER PT J AU Riotto, A Vilja, I AF Riotto, A Vilja, I TI Propagation of Majorana fermions in hot plasma SO PHYSICS LETTERS B LA English DT Article ID STANDARD MODEL; ELECTROWEAK BARYOGENESIS; HIGH-TEMPERATURE; GAUGE-THEORIES; HOLES AB The properties of Majorana fermions in hot plasma are studied. One-loop resummed propagator, dispersion relations and their interpretation are discussed. It is shown that particle and hole-like solutions appear as in Dirac/chiral fermion case. The dispersion relations are, however, crucially different. We find that, in the presence of a large zero temperature bare mass, hole-hire excitations possess a negligible effective mass. As an example of a real application, we consider the neutralinos in the minimal supersymmetric extension of the standard model and argue that for realistic values of the soft supersymmetry breaking masses the existence of practically massless hole-like excitations has a considerable effect on the thermal properties, e.g. the thermalization rate, of particles interacting with these Majorana excitations. (C) 1997 Published by Elsevier Science B.V. C1 UNIV TURKU,DEPT PHYS,FIN-20014 TURKU,FINLAND. RP Riotto, A (reprint author), NASA,FERMILAB ASTROPHYS CTR,FERMI NATL ACCELERATOR LAB CTR,POB 500,BATAVIA,IL 60510, USA. NR 17 TC 10 Z9 10 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD JUN 12 PY 1997 VL 402 IS 3-4 BP 314 EP 319 DI 10.1016/S0370-2693(97)00468-1 PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA XG329 UT WOS:A1997XG32900012 ER PT J AU Creutz, M Tytgat, M Rebbi, C Xue, SS AF Creutz, M Tytgat, M Rebbi, C Xue, SS TI Lattice formulation of the standard model SO PHYSICS LETTERS B LA English DT Article ID CHIRAL GAUGE-THEORIES; DOMAIN-WALL FERMIONS; WAVE-GUIDE; ANOMALIES; SYMMETRY; OVERLAP; REGULARIZATION; CONSTRUCTION; CONTINUUM; FIELDS AB Combining the Kaplan surface mode approach for chiral fermions with added terms motivated by Eichten and Preskill suggests the possibility for a lattice regularization of the standard model which is finite, exactly gauge invariant, and only has physically desired states in its low energy spectrum. The conjectured scheme manifestly requires anomaly cancelation and explicitly contains baryon and lepton number violating terms. Published by Elsevier Science B.V. C1 BOSTON UNIV, DEPT PHYS, BOSTON, MA 02215 USA. IST NAZL FIS NUCL, SECT MILAN, I-20133 MILAN, ITALY. RP BROOKHAVEN NATL LAB, DEPT PHYS, UPTON, NY 11973 USA. NR 47 TC 28 Z9 28 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 EI 1873-2445 J9 PHYS LETT B JI Phys. Lett. B PD JUN 12 PY 1997 VL 402 IS 3-4 BP 341 EP 345 DI 10.1016/S0370-2693(97)00463-2 PG 5 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA XG329 UT WOS:A1997XG32900016 ER PT J AU Skinner, CJ Exter, KM Barlow, MJ Davis, RJ Bode, MF AF Skinner, CJ Exter, KM Barlow, MJ Davis, RJ Bode, MF TI A compact, variable radio nebula around P Cygni SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Letter DE stars, early-type; stars, imaging; stars, individual, P Cygni ID STELLAR WIND; MASS-LOSS; STARS AB We present high spatial resolution images, at a wavelength of 6 cm, of the luminous blue variable star P Cygni. The images fully resolve the core of the stellar wind, and show that it is very clumpy. Two images were taken, separated in time by approximately a month, during which the structure in the wind has changed radically. The total flux observed has also changed significantly. We show that the clump sizes and electron densities are consistent with the radio variability being due to recombination of the ionized gas within the clumps, after key cooling lines become optically thin, causing the free-free emission to disappear. This is the first time that resolved radio images of a hot star wind have been obtained. It also represents important confirmation of a previous observation that thermal free-free wind emission can vary rapidly in a hot stellar wind. C1 LAWRENCE LIVERMORE NATL LAB,INST GEOPHYS & PLANETARY PHYS,LIVERMORE,CA 94551. LAWRENCE LIVERMORE NATL LAB,EXPT ASTROPHYS LAB,LIVERMORE,CA 94551. UNIV ST ANDREWS,SCH PHYS & ASTRON,ST ANDREWS KY16 9SS,FIFE,SCOTLAND. UNIV LONDON UNIV COLL,DEPT PHYS & ASTRON,LONDON WC1E 6BT,ENGLAND. NUFFIELD RADIO ASTRON OBSERV LABS,MACCLESFIELD SK11 9DL,CHESHIRE,ENGLAND. LIVERPOOL JOHN MOORES UNIV,SCH CHEM & PHYS SCI,LIVERPOOL L3 3AF,MERSEYSIDE,ENGLAND. RP Skinner, CJ (reprint author), SPACE TELESCOPE SCI INST,3700 SAN MARTIN DR,BALTIMORE,MD 21218, USA. RI Barlow, Michael/A-5638-2009 OI Barlow, Michael/0000-0002-3875-1171 NR 15 TC 16 Z9 16 U1 0 U2 0 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0NE SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD JUN 11 PY 1997 VL 288 IS 1 BP L7 EP L10 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA XF091 UT WOS:A1997XF09100002 ER PT J AU Fedchak, JA Cabauy, P Cummings, WJ Jones, CE Kowalczyk, RS AF Fedchak, JA Cabauy, P Cummings, WJ Jones, CE Kowalczyk, RS TI Silane coatings for laser-driven polarized hydrogen sources and targets SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID ATOMIC-HYDROGEN; DEUTERIUM; RELAXATION; VAPOR AB It is necessary to use special coatings on the surfaces of volumes containing polarized atoms in order to minimize depolarizing spin interactions during wall collisions. We are studying coatings of organosilicon compounds that preserve hydrogen and potassium polarizations and prevent molecular recombination of hydrogen during wall collisions in a laser-driven polarized hydrogen source. Continuing problems with coatings for these sources has been the reproducibility of high-quality surfaces and reliable assessment of surface quality before installation of coated parts in the laser-driven source. We have used an atomic force microscope to scan surfaces coated with different organosilicon compounds with the goal of assessing surface quality and determining a method of preparing reproducible surfaces that do not degrade with time. Here we show AFM scans of the different coatings, discuss the quality of coatings made with different chemicals and application procedures, and present the results of coating stability tests as a function of temperature and exposure to potassium. We find that a simple organosilicon afterwash gives a significantly improved surface. RP Fedchak, JA (reprint author), ARGONNE NATL LAB,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 13 TC 15 Z9 16 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 11 PY 1997 VL 391 IS 3 BP 405 EP 416 DI 10.1016/S0168-9002(97)00571-8 PG 12 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XM586 UT WOS:A1997XM58600003 ER PT J AU Datte, P Beuville, E Beche, JF Cork, C Earnest, T Millaud, J Nygren, D Padmore, H Turko, B Xuong, NH AF Datte, P Beuville, E Beche, JF Cork, C Earnest, T Millaud, J Nygren, D Padmore, H Turko, B Xuong, NH TI A prototype 8x8 pixel array X-ray detector for protein crystallography SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE crystallography; pixel detector; image sensor; Si; CdZnTe; area detector AB An 8 x 8 pixel array X-ray detector prototype (< 15 keV) has been built and tested. This room temperature detector will significantly enhance time resolved Laue Protein Crystallography by two or three orders of magnitude compared to the present crystallographic phosphor imaging plates and CCD-type detectors. In addition, the detector will greatly accelerate the monochromatic crystallography data collection at synchrotron light sources where very intense X-ray fluxes above 5 x 10(8) photons/cm(2)/s are obtained. The detectors event-driven read out is based on the column architecture which can provide energy discrimination and sparse and frameless output displaying minimal dead time. For the targeted detector size of (1000 x 1000) pixels, average hit rates greater than 8 x 10(7) photons/s for the entire area appears achievable. To characterize the analog portion of the read out and the digital characteristics of the detector, the pixel electronics contains only the analog portion of the circuit and is independent of the surrounding cells. The conversion of a photon hit into a pixel address is generated by conventional external electronics. The measured results are very encouraging. The analog electronics demonstrate the capability of processing charge pulses at a rate of 1 x 10(6) photons/s/pixel, with an energy resolution of 480 eV (FWHM at 5.9 keV) at room temperature. The detector displays uniform digital behavior and has a very low point-spread function. The full-width at 1/100 maximum is less than 1 pixel width (150 mu m), which is less than (1/2) that of a CCD and (1/7) that of an imaging plate detector [1]. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP Datte, P (reprint author), UNIV CALIF SAN DIEGO,DEPT CHEM & BIOCHEM,LA JOLLA,CA 92093, USA. NR 15 TC 6 Z9 6 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JUN 11 PY 1997 VL 391 IS 3 BP 471 EP 480 DI 10.1016/S0168-9002(97)00574-3 PG 10 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XM586 UT WOS:A1997XM58600012 ER PT J AU Wang, Y Turner, EL AF Wang, Y Turner, EL TI Statistics of extreme gravitational lensing events .2. The finite shear case SO ASTROPHYSICAL JOURNAL LA English DT Article DE gravitational lensing ID STAR DISTURBANCES; FLUX VARIATIONS; GALAXIES AB We consider an astrophysical system with a population of sources and a population of lenses. For each pair of source and lens, there is a thin on-axis tubelike volume behind the lens in which the radiation flux from the source is greatly increased as a result of gravitational lensing. Any objects (such as dust grains) which pass through such a thin tube will experience strong bursts of radiation, i.e., extreme gravitational lensing events (EGLEs). We study the physics and statistics of EGLEs for the case in which the shear is larger than or comparable to the finite source size. We find that the presence of shear has only a small effect on the EGLE statistics. C1 FERMILAB NATL ACCELERATOR LAB,FERMILAB ASTROPHYS CTR,NASA,BATAVIA,IL 60510. RP Wang, Y (reprint author), PRINCETON UNIV OBSERV,PEYTON HALL,PRINCETON,NJ 08544, USA. RI Wang, Yun/B-5724-2011; Turner, Edwin/A-4295-2011 OI Wang, Yun/0000-0002-4749-2984; NR 8 TC 1 Z9 1 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 10 PY 1997 VL 482 IS 1 BP 63 EP 67 DI 10.1086/304115 PN 1 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA XD370 UT WOS:A1997XD37000007 ER PT J AU Alcock, C Allsman, RA Alves, D Axelrod, TS Becker, AC Bennett, DP Cook, KH Freeman, KC Griest, K Guern, J Lehner, MJ Marshall, SL Minniti, D Peterson, BA Pratt, MR Quinn, PJ Rodgers, AW Sutherland, W Welch, DL AF Alcock, C Allsman, RA Alves, D Axelrod, TS Becker, AC Bennett, DP Cook, KH Freeman, KC Griest, K Guern, J Lehner, MJ Marshall, SL Minniti, D Peterson, BA Pratt, MR Quinn, PJ Rodgers, AW Sutherland, W Welch, DL TI The MACHO Project Large Magellanic Cloud variable star inventory .3. Multimode RR Lyrae stars, distance to the large magellanic cloud, and age of the oldest stars SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies, distances and redshifts; Magellanic Clouds; stars, oscillations; stars, variables, other (RR Lyrae) ID HORIZONTAL-BRANCH STARS; GLOBULAR-CLUSTERS; PHOTOMETRY; ISOCHRONES; SEQUENCES; SYSTEM AB We report the discovery of 73 double-mode RR Lyrae (RRd) stars in fields near the bar of the Large Magellanic Cloud (LMC). The stars are detected among the MACHO database of short-period variables that currently contains about 7900 RR Lyrae stars. Fundamental periods (P-0) for these stars are found in the range 0.45-0.55 days, and first-overtone-to-fundamental period ratios are found to be in the range 0.742 < P-1/P-0 < 0.748. The range in period ratios is unexpectedly large, and a significant fraction of our current sample has period ratios smaller than any previously discovered RRd variables. We present mean magnitudes, colors, and light-curve properties for all LMC RRd stars detected to date. We undertake a determination of the absolute magnitudes for these stars based primarily on pulsation theory and on the assumption that all observed stars are at the fundamental blue edge of the instability strip. Comparison of the calibrated MACHO V and R-KC photometry with these derived absolute magnitudes yields an absorption-corrected distance modulus to the LMC of 18.48 +/- 0.19 mag that is in good agreement with that found (18.5) through comparison of Galactic and LMC Cepheids. Exploring this luminosity calibration, we derive an increase in the distance modulus, and thus a reduction in the age found via isochrone fitting, for M15 of about 30% and discuss some implications for cosmology. C1 UNIV CALIF BERKELEY,CTR PARTICLE ASTROPHYS,BERKELEY,CA 94720. AUSTRALIAN NATL UNIV,SUPERCOMP FACIL,CANBERRA,ACT 0200,AUSTRALIA. AUSTRALIAN NATL UNIV,MT STROMLO & SIDING SPRING OBSERV,WESTON,ACT 2611,AUSTRALIA. UNIV WASHINGTON,DEPT ASTRON,SEATTLE,WA 98195. UNIV WASHINGTON,DEPT PHYS,SEATTLE,WA 98195. UNIV CALIF SAN DIEGO,DEPT PHYS,LA JOLLA,CA 92093. UNIV CALIF SANTA BARBARA,DEPT PHYS,SANTA BARBARA,CA 93106. EUROPEAN SO OBSERV,D-85748 GARCHING,GERMANY. UNIV OXFORD,DEPT PHYS,OXFORD OX 3RH,ENGLAND. UNIV OXFORD,ASTROPHYS LAB,OXFORD OX 3RH,ENGLAND. MCMASTER UNIV,DEPT PHYS & ASTRON,HAMILTON,ON L8S 4M1,CANADA. RP Alcock, C (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. RI Quinn, Peter/B-3638-2013 NR 40 TC 54 Z9 54 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JUN 10 PY 1997 VL 482 IS 1 BP 89 EP 97 DI 10.1086/304120 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA XD370 UT WOS:A1997XD37000011 ER PT J AU Barbero, JF Dominguez, A Goldman, T PerezMercader, J AF Barbero, JF Dominguez, A Goldman, T PerezMercader, J TI Dynamical critical phenomena and large-scale structure of the Universe: The power spectrum for density fluctuations SO EUROPHYSICS LETTERS LA English DT Article ID RENORMALIZATION-GROUP ANALYSIS; EQUATION AB As is well known, structure formation in the Universe at times after decoupling can be described by hydrodynamic equations. These are shown here to be equivalent to a generalization of the stochastic Kardar-Parisi-Zhang equation. As a consequence of the dynamical critical scaling induced by noise, these equations describe the fractal behavior observed at the smaller scales for the galaxy-to-galaxy correlation function and also the Harrison-Zel'dovich spectrum at decoupling. By a renormalization group calculation of the two-point correlation function between galaxies we can account, from first principles, for the main features of the observed shape of the power spectrum. C1 LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. CSIC,IMAFF,MADRID,SPAIN. RP Barbero, JF (reprint author), LAB ASTROFIS ESPACIAL & FIS FUNDAMENTAL,APARTADO 50727,MADRID 28080,SPAIN. RI Dominguez Alvarez, Alvaro/K-2266-2014 OI Dominguez Alvarez, Alvaro/0000-0002-8529-9667 NR 13 TC 14 Z9 15 U1 0 U2 3 PU EDITIONS PHYSIQUE PI LES ULIS CEDEX PA Z I DE COURTABOEUF AVE 7 AV DU HOGGAR, BP 112, 91944 LES ULIS CEDEX, FRANCE SN 0295-5075 J9 EUROPHYS LETT JI Europhys. Lett. PD JUN 10 PY 1997 VL 38 IS 8 BP 637 EP 642 PG 6 WC Physics, Multidisciplinary SC Physics GA XE639 UT WOS:A1997XE63900013 ER PT J AU Phillips, WS House, LS Fehler, MC AF Phillips, WS House, LS Fehler, MC TI Detailed joint structure in a geothermal reservoir from studies of induced microearthquake clusters SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID RESOLUTION RELATIVE HYPOCENTERS; EARTHQUAKE DOUBLETS; CRYSTALLINE ROCK; FLUID-FLOW; FAULT; SEISMICITY; CALIFORNIA; PARKFIELD; SIMILARITY; RECURRENCE AB Microearthquake clusters form distinct, planar patterns within five study regions of a geothermal reservoir undergoing hydraulic fracturing at Fenton Hill, New Mexico. The patterns define individual, slipping joint surfaces of dimension 40-120 m, containing 80-150 events each. Sharp, straight edges truncate the clusters; we interpret these as marking intersections with aseismic joints. Each edge orientation is consistent with an intersection between the active joint and a plane oriented parallel to one of the other clusters we identify. Therefore it appears that cluster shapes constrain the geometry of seismic and aseismic joints; both could be important components of the fluid-flow network. The distribution of inferred slip plane orientations is consistent with but fails to provide sufficient constraint to differentiate conclusively between two, very different, stress field estimates, one measured using pressurization and wellbore breakouts, the other using focal mechanisms of the largest microearthquakes. An impermeable joint model, requiring pore pressure in excess of the normal stress on a joint before slip can occur, was inconsistent with many of the inferred slip plane orientations. The high-quality locations were possible because events from the same cluster generated nearly similar waveforms, permitting the precise determination of relative arrival times. Standard deviations of arrival-time residuals fall between 0.1 and 1.1 ms for these clusters. Major axes and aspect ratios of the 90% confidence ellipsoids range from 6 to 28 m and 1.5 to 8, respectively. Small events dominate the seismic energy release and thoroughly populate the identified, active joints, allowing the hypocenters to reflect details of the joint structure. To further investigate the reservoir structure, we applied a source-array, slant-stack technique to waveforms from the well-located clusters, yielding directions that scattered energy left each cluster. By studying paths of scattered waves we expected to pinpoint impedance contrasts that might have indicated concentrations of fluid-filled joints. However, results show that scattered energy in the S wave coda left the source region in the same direction as the direct S wave. Direct waves may have excited borehole tube waves that became trapped in the vicinity of the geophone tool, overwhelming any energy scattered from the reservoir. RP Phillips, WS (reprint author), LOS ALAMOS NATL LAB, DIV EARTH & ENVIRONM SCI, MS C335, LOS ALAMOS, NM 87545 USA. NR 51 TC 48 Z9 50 U1 1 U2 8 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 JUN 10 PY 1997 VL 102 IS B6 BP 11745 EP 11763 DI 10.1029/97JB00762 PG 19 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA XD578 UT WOS:A1997XD57800006 ER PT J AU Bunge, HP Richards, MA Baumgardner, JR AF Bunge, HP Richards, MA Baumgardner, JR TI A sensitivity study of three-dimensional spherical mantle convection at 10(8) Rayleigh number: Effects of depth-dependent viscosity, heating mode, and an endothermic phase change SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Review ID LONG-WAVELENGTH HETEROGENEITY; 2-POINT CORRELATION-FUNCTIONS; PRESSURE-TEMPERATURE SLOPES; INFINITE PRANDTL NUMBER; EARTHS MANTLE; SYSTEM MG2SIO4-FE2SIO4; THERMAL EXPANSIVITY; LATERAL HETEROGENEITY; SUBDUCTED LITHOSPHERE; LAYERED CONVECTION AB Mantle convection is influenced simultaneously by a number of physical effects: brittle failure in the surface plates, strongly variable viscosity, mineral phase changes; and both internal heating (radioactivity) and bottom heating from the core. Here we present a systematic study of three potentially important effects: depth-dependent viscosity, an endothermic phase; change, and bottom versus internal heating. We model three-dimensional spherical convection at Rayleigh Ra = 10(8) thus approaching the dynamical regime of the mantle. An,isoviscous, internally heated reference model displays point-like downwellings from the cold upper boundary layer, a blue spectrum of thermal heterogeneity, and small but rapid time variations in flow diagnostics. A modest factor 30 increase in-lower mantle viscosity results in a planform dominated by long, linear downwellings, a red spectrum, and great temporal stability. Bottom heating has the predictable effect of adding a thermal boundary layer at the base of the mantle; We use a Clapeyron slope of gamma = -4 MPa degrees K-1 for the 670 km phase transition, resulting in a phase buoyancy parameter of P = -0.112. This phase change causes upwellings and downwellings to pause in the transition zone brit has little influence on the inherent time dependence of flow and only a modest reddening effect on the heterogeneity spectrum. Larger values of P result in stronger effects, but our choice of P is likely already too large to be representative of the mantle transition zone. Combinations of all three effects are remarkably predictable in terms of the single-effect models, and the effect of depth-dependent viscosity is found to be dominant. C1 LOS ALAMOS NATL LAB, DIV THEORET, LOS ALAMOS, NM 87545 USA. UNIV CALIF BERKELEY, DEPT GEOL & GEOPHYS, BERKELEY, CA 94720 USA. RP LOS ALAMOS NATL LAB, INST GEOPHYS & PLANETARY PHYS, DEPT GEOL & GEOPHYS, MS 305, LOS ALAMOS, NM 87545 USA. NR 121 TC 151 Z9 152 U1 0 U2 12 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 JUN 10 PY 1997 VL 102 IS B6 BP 11991 EP 12007 DI 10.1029/96JB03806 PG 17 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA XD578 UT WOS:A1997XD57800022 ER PT J AU Abramson, EH Brown, JM Slutsky, LJ Zaug, JM AF Abramson, EH Brown, JM Slutsky, LJ Zaug, JM TI The elastic constants of San Carlos olivine to 17 GPa SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID MANTLE PRESSURES; FORSTERITE; VELOCITIES AB All elastic constants, the average bulk and shear moduli, and the lattice parameters of San Carlos olivine (Fo(90)) (initial density 3.355 gm/cm(3)) have been determined to a pressure of 12 Gpa at room temperature. Measurements of c(11), c(33), c(13), and c(55) have been extended to 17 GPa. The pressure dependence of the adiabatic, isotropic (Hashin-Shtrikman bounds) bulk modulus, and shear modulus may be expressed as K-HS = 129.4 + 4.29 P and by G(HS) = 78 + 1.71P - 0.027 P-2, where both the pressure and the moduli are in gigapascals. The isothermal compression of olivine is described by a bulk modulus given as K-T = 126.3 + 4.28 P. Elastic constants other than c(55) can be adequately represented by a linear relationship in pressure. In the order (c(11), c(12), c(13), c(22), c(33), c(44), c(55), c(66)) the 1 bar intercepts (gigapascal units) are (320.5, 68.1, 71.6, 196.5, 76.8, 233.5, 64.0, 77.0, 78.7). The first derivatives are (6.54, 3.86, 3.57, 5.38, 3.37, 5.51, 1.67, 1.81, 1.93). The second derivative for c(55) is -0.070 GPa(-1). Incompressibilities for the three axes may also be expressed as linear relationships with pressure. In the order of a, b, and c axes the intercepts in gigapascals are (547.8, 285.8, 381.8) and the first derivatives are (20.1, 12.3, 14.0). C1 UNIV WASHINGTON, GEOPHYS PROGRAM, SEATTLE, WA 98195 USA. LOS ALAMOS NATL LAB, LOS ALAMOS, NM 87545 USA. RP Abramson, EH (reprint author), UNIV WASHINGTON, DEPT CHEM, SEATTLE, WA 98195 USA. OI abramson, evan/0000-0001-5278-0836 NR 24 TC 165 Z9 169 U1 3 U2 21 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 JUN 10 PY 1997 VL 102 IS B6 BP 12253 EP 12263 DI 10.1029/97JB00682 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA XD578 UT WOS:A1997XD57800038 ER PT J AU Magowan, C Brown, JT Liang, J Heck, J Coppel, RL Mohandas, N MeyerIlse, W AF Magowan, C Brown, JT Liang, J Heck, J Coppel, RL Mohandas, N MeyerIlse, W TI Intracellular structures of normal and aberrant Plasmodium falciparum malaria parasites imaged by soft x-ray microscopy SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID INFECTED ERYTHROCYTES; HEMOGLOBIN DEGRADATION; CYSTEINE PROTEINASE; CELL MEMBRANE; SURFACE; ANTIGEN; SPECTRIN; CYTOADHERENCE; ASSOCIATION; INHIBITORS AB Soft x-ray microscopy is a novel approach for investigation of intracellular organisms and subcellular structures with high spatial resolution, We used x-ray microscopy to investigate structural development of Plasmodium falciparum malaria parasites in normal and genetically abnormal erythrocytes and in infected erythrocytes treated with cysteine protease inhibitors, Investigations in normal red blood cells enabled us to recognize anomalies in parasite structures resulting from growth under unfavorable conditions, X-ray microscopy facilitated detection of newly elaborated structures in the cytosol of fixed, unstained, intact erythrocytes, redistribution of mass (carbon) in infected erythrocytes, and aberrant parasite morphology, In cysteine protease inhibitor-treated, infected erythrocytes, high concentrations of material were detected in abnormal digestive vacuoles and aggregated at the parasite plasma membrane, We have demonstrated that an abnormal host erythrocyte skeleton affects structural development of parasites and that this aberrant development can be detected in the following generation when parasites from protein 4.1-deficient red blood cells infect normal erythrocytes, This work extends our current understanding of the relationship between the host erythrocyte membrane and the intraerythrocytic malaria parasite by demonstrating for the first time that constituents of the erythrocyte membrane play a role in normal parasite structural development. C1 LAWRENCE BERKELEY LAB,CTR XRAY OPT,BERKELEY,CA 94720. MONASH UNIV,DEPT MICROBIOL,CLAYTON,VIC 3168,AUSTRALIA. RP Magowan, C (reprint author), LAWRENCE BERKELEY LAB,DIV LIFE SCI,1 CYCLOTRON RD,BERKELEY,CA 94720, USA. RI Coppel, Ross/A-6626-2008 OI Coppel, Ross/0000-0002-4476-9124 FU NIDDK NIH HHS [DK32094-10, P01 DK032094] NR 41 TC 35 Z9 36 U1 0 U2 3 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 JUN 10 PY 1997 VL 94 IS 12 BP 6222 EP 6227 DI 10.1073/pnas.94.12.6222 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA XD844 UT WOS:A1997XD84400047 PM 9177198 ER PT J AU Hein, L Stevens, ME Barsh, GS Pratt, RE Kobilka, BK Dzau, VJ AF Hein, L Stevens, ME Barsh, GS Pratt, RE Kobilka, BK Dzau, VJ TI Overexpression of angiotensin AT(1) receptor transgene in the mouse myocardium produces a lethal phenotype associated with myocyte hyperplasia and heart block SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID LEFT-VENTRICULAR HYPERTROPHY; T-ANTIGEN TRANSGENES; CHAIN GENE PROMOTER; CARDIAC-HYPERTROPHY; RAT-HEART; TRANSFORMING GROWTH-FACTOR-BETA-1; CELL COMMUNICATION; II STIMULATION; MESSENGER-RNA; SYSTEM AB Previous studies have suggested that angiotensin II (Ang II) modulates cardiac contractility, rhythm, metabolism, and structure, However, it is unclear whether the cardiac effects are due to direct actions of Ang II on the myocardium or if they are due to secondary effects mediated through the hemodynamic actions of Ang II, In this study, we used the alpha-myosin heavy chain (alpha MHC) promoter to generate transgenic mice overexpressing angiotensin II type 1 (AT(1a)) receptor selectively in cardiac myocytes, The specificity of transgene expression in the transgenic offspring was confirmed by radioligand binding studies and reverse transcription-PCR, The offspring displayed massive atrial enlargement with myocyte hyperplasia at birth, developed significant bradycardia with heart block, and died within the first weeks after birth, Thus, direct activation of AT(1) receptor signaling in cardiac myocytes in vivo is sufficient to induce cardiac myocyte growth and alter electrical conduction. C1 STANFORD UNIV,SCH MED,FALK CARDIOVASC RES CTR,STANFORD,CA 94305. STANFORD UNIV,SCH MED,DEPT MED,STANFORD,CA 94305. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV LIFE SCI,BERKELEY,CA 94720. STANFORD UNIV,SCH MED,DEPT PEDIAT,STANFORD,CA 94305. STANFORD UNIV,SCH MED,DEPT GENET,STANFORD,CA 94305. STANFORD UNIV,SCH MED,BECKMAN CTR,HOWARD HUGHES MED INST,STANFORD,CA 94305. FU NHLBI NIH HHS [HL42663, HL35610, HL48638, R01 HL035610, R37 HL035610] NR 49 TC 166 Z9 168 U1 0 U2 1 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 JUN 10 PY 1997 VL 94 IS 12 BP 6391 EP 6396 DI 10.1073/pnas.94.12.6391 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA XD844 UT WOS:A1997XD84400077 PM 9177228 ER PT J AU Wang, H Biesecker, JP Iedema, MJ Ellison, GB Cowin, JP AF Wang, H Biesecker, JP Iedema, MJ Ellison, GB Cowin, JP TI Low-energy deposition and collision-induced dissociation of water ions on Pt(111) SO SURFACE SCIENCE LA English DT Article DE ion-solid interactions; ion-solid interactions, scattering, channeling; low index single crystal surfaces; platinum; single crystal surfaces; solid-gas interfaces; sticking; water ID SURFACE COLLISIONS; IMPACT ENERGIES; NI(111) SURFACE; KINETIC-ENERGY; SOLID-SURFACES; PRESSURE GAP; CHEMISORPTION; BEAM; ADSORPTION; HYDROGEN AB We studied collision-induced D2O+ dissociation on Pt(111) using a low-energy ion source (developed at PNNL and The University of Colorado) and temperature-programmed desorption (TPD). D2O+ ions were deposited on the surface at energies ranging from 3 to 27 eV. The molecular sticking probability decreases rapidly with kinetic energy, from 0.14 at 3 eV to 0.04 at 27 eV. The dissociative adsorption probability (in terms of surface D atoms produced) increases from 0 at 10 eV to 0.8 deuteriums per incident ion at 27 eV. The dissociation appears to involve oxygen ejection, since TPD after deposition shows D-2 but no oxygen other than in water. This dissociation threshold is higher than for published results for CO+ and N-2(+) hitting metal surfaces. This is because metal electrons should neutralize D2O+ to the ground electronic state, limiting its internal energy available for dissociation. (C) 1997 Elsevier Science B.V. C1 PACIFIC NW LAB, ENVIRONM MOL SCI LAB, RICHLAND, WA 99352 USA. UNIV COLORADO, DEPT CHEM & BIOCHEM, BOULDER, CO 80309 USA. NR 52 TC 6 Z9 6 U1 3 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD JUN 10 PY 1997 VL 381 IS 2-3 BP 142 EP 156 DI 10.1016/S0039-6028(97)00103-9 PG 15 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA XH805 UT WOS:A1997XH80500017 ER PT J AU Materer, N Starke, U Barbieri, A VanHove, MA Somorjai, GA Kroes, GJ Minot, C AF Materer, N Starke, U Barbieri, A VanHove, MA Somorjai, GA Kroes, GJ Minot, C TI Molecular surface structure of ice(0001): Dynamical low-energy electron diffraction, total-energy calculations and molecular dynamics simulations SO SURFACE SCIENCE LA English DT Article DE ab initio quantum chemical methods and calculations; Auger electron spectroscopy; crystallization; electron-solid diffraction; electron-solid interactions, scattering, diffraction; epitaxy; low energy electron diffraction (LEED); low index single crystal surfaces; molecular dynamics; single crystal surfaces; surface melting; surface relaxation and reconstruction; surface structure, morphology, roughness, and topography; vibrations of adsorbed molecules; water ID X-RAY-SCATTERING; COMPUTER-SIMULATION; SINGLE-CRYSTALS; WATER INTERFACE; IONIC-CRYSTAL; ICE; ADSORPTION; PT(111); CLUSTERS; BILAYER AB A structural study of the surface of an ultrathin ice film grown on a Pt(lll) substrate was performed using dynamical low-energy electron diffraction (LEED) at 90 K, together with total-energy calculations and molecular dynamics (MD) simulations. This ice film exhibits the common hexagonal phase Ih and exposes the (0001) surface without reconstruction. The surface is terminated as a full-bilayer that maximizes the number of surface hydrogen bonds as confirmed by our total-energy calculations. Both LEED and MD simulations End that the outermost water molecules have enhanced vibrational amplitudes making them practically undetectable by LEED even at 90 K. MD simulations of the half-bilayer terminated surface yield results inconsistent with the LEED findings, thus excluding this model. (C) 1997 Elsevier Science B.V. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. VRIJE UNIV AMSTERDAM,DEPT CHEM,NL-1081 HV AMSTERDAM,NETHERLANDS. UNIV PARIS 06,CHIM THEOR LAB,URA 560,F-75230 PARIS,FRANCE. RI Van Hove, Michel/A-9862-2008 OI Van Hove, Michel/0000-0002-8898-6921 NR 51 TC 122 Z9 124 U1 5 U2 30 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD JUN 10 PY 1997 VL 381 IS 2-3 BP 190 EP 210 DI 10.1016/S0039-6028(97)00090-3 PG 21 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA XH805 UT WOS:A1997XH80500021 ER PT J AU Lee, DH Lee, H Park, B Poker, DB Riester, L AF Lee, DH Lee, H Park, B Poker, DB Riester, L TI The effect of implantation temperature on the surface hardness, elastic modulus and Raman scattering in amorphous carbon SO APPLIED PHYSICS LETTERS LA English DT Article ID IRRADIATED GLASSY-CARBON; SUBPLANTATION MODEL; FILM GROWTH; DIAMOND; SPECTROSCOPY AB Nitrogen implantation into amorphous carbon has been studied at various implantation temperatures by using 100 keV N+ at 5 mu A and fluences of 2 x 10(17) ions/cm(2). The apparent surface hardness and elastic modulus from nanoindentation are well correlated with an asymmetric diffuse peak at around 1500 cm(-1) and a broad band at similar to 700 cm(-1) in the Raman spectra. Both the enhanced strengths and Raman characteristics show very weak Arrhenius-type implantation-temperature dependence with activation enthalpies of approximately 20 meV in the temperature range 223-1073 K. (C) 1997 American Institute of Physics. C1 GEORGIA INST TECHNOL,SCH MAT SCI & ENGN,ATLANTA,GA 30332. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RI Park, Byungwoo/F-5431-2013 NR 18 TC 17 Z9 18 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 JUN 9 PY 1997 VL 70 IS 23 BP 3104 EP 3106 DI 10.1063/1.119092 PG 3 WC Physics, Applied SC Physics GA XD343 UT WOS:A1997XD34300013 ER PT J AU Markovich, G Leff, DV Chung, SW Soyez, HM Dunn, B Heath, JR AF Markovich, G Leff, DV Chung, SW Soyez, HM Dunn, B Heath, JR TI Parallel fabrication and single-electron charging of devices based on ordered, two-dimensional phases of organically functionalized metal nanocrystals SO APPLIED PHYSICS LETTERS LA English DT Article ID QUANTUM DOTS; CLUSTERS; NANOPARTICLES; COLLOIDS; POLYMER; SIZE AB A parallel technique for fabricating single-electron, solid-state capacitance devices from ordered, two-dimensional closest-packed phases of organically functionalized metal nanocrystals is presented. The nanocrystal phases were prepared as Langmuir monolayers and subsequently transferred onto Al-electrode patterned glass substrates for device construction. Alternating current impedance measurements were carried out to probe the single-electron charging characteristics of the devices under both ambient and 77 K conditions. Evidence of a Coulomb blockade and step structure reminiscent of a Coulomb staircase is presented. (C) 1997 American Institute of Physics. C1 UNIV CALIF LOS ANGELES,INST MOL DESIGN,LAWRENCE BERKELEY LAB,LOS ANGELES,CA 90095. UNIV CALIF LOS ANGELES,DEPT CHEM & BIOCHEM,LOS ANGELES,CA 90095. UNIV CALIF LOS ANGELES,DEPT MAT SCI & ENGN,LOS ANGELES,CA 90095. RI Markovich, Gil /B-8178-2009 NR 28 TC 56 Z9 56 U1 1 U2 5 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 JUN 9 PY 1997 VL 70 IS 23 BP 3107 EP 3109 DI 10.1063/1.119105 PG 3 WC Physics, Applied SC Physics GA XD343 UT WOS:A1997XD34300014 ER PT J AU Wallis, DJ Browning, ND Sivananthan, S Nellist, PD Pennycook, SJ AF Wallis, DJ Browning, ND Sivananthan, S Nellist, PD Pennycook, SJ TI Atomic layer graphoepitaxy for single crystal heterostructures SO APPLIED PHYSICS LETTERS LA English DT Article ID GROWTH AB Here we report a strategy for the growth of single crystal heterostructures that dramatically reduces the nucleation of defects at the film-substrate interface. The substrate surface is patterned through miscut and passivated to enable a single domain template layer to be grown. This template is incommensurate with, and weakly bonded to, the substrate. A single domain film can then be nucleated preferentially at step edges and grown on the template. This mechanism is demonstrated for CdTe on Si(100) and should be applicable to many other systems. (C) 1997 American Institute of Physics. C1 OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. RP Wallis, DJ (reprint author), UNIV ILLINOIS,DEPT PHYS,M-C 273,CHICAGO,IL 60607, USA. OI Browning, Nigel/0000-0003-0491-251X NR 11 TC 14 Z9 14 U1 0 U2 6 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 JUN 9 PY 1997 VL 70 IS 23 BP 3113 EP 3115 DI 10.1063/1.119107 PG 3 WC Physics, Applied SC Physics GA XD343 UT WOS:A1997XD34300016 ER PT J AU Smith, PM Custer, JS AF Smith, PM Custer, JS TI Chemical vapor deposition of titanium-silicon-nitride films SO APPLIED PHYSICS LETTERS LA English DT Article ID DIFFUSION-BARRIERS; THIN-FILMS; TEMPERATURE AB Titanium-silicon-nitride films were grown by metal-organic chemical vapor deposition. At temperatures between 300 and 450 degrees C, tetrakis(diethylamido)titanium, ammonia, and silane react to form films with average compositions near the TiN-Si3N4 tie line and low impurity contents (C<1.5 at. %, H between 5 and 15 at. %, with no other impurities present). The film resistivity is a strong function of Si content in the films, ranging continuously from 400 mu Ohm cm for pure TiN up to 1 Ohm cm for films with 25 at. % Si. Step coverages of approximately 75% on 0.35 mu m, 3:1 aspect ratio trenches, and 35%-40% on 0.1 mu m/10: 1 trenches are found for films with resistivities below 1000 mu Omega cm. These films are promising candidates for diffusion barriers in microelectronic applications. (C) 1997 American Institute of Physics. RP Smith, PM (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 19 TC 51 Z9 51 U1 1 U2 3 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 JUN 9 PY 1997 VL 70 IS 23 BP 3116 EP 3118 DI 10.1063/1.119108 PG 3 WC Physics, Applied SC Physics GA XD343 UT WOS:A1997XD34300017 ER PT J AU Goodwin, TJ Leppert, VJ Risbud, SH Kennedy, IM Lee, HWH AF Goodwin, TJ Leppert, VJ Risbud, SH Kennedy, IM Lee, HWH TI Synthesis of gallium nitride quantum dots through reactive laser ablation SO APPLIED PHYSICS LETTERS LA English DT Article ID NANOCLUSTERS; POWDERS; SILICON AB Nanocrystalline GaN was synthesized through reactive laser ablation of gallium metal in a Nz atmosphere. X-ray diffraction, selected-area electron diffraction, and transmission electron microscopy measurements show that the GaN crystallites are as small as 2 nm in diameter, and follow a log-normal size distribution with a mean particle diameter of 12 nm. Size-selective photoluminescence and photoluminescence excitation spectroscopy reveal a continuous range of blueshifted band-edge emissions and absorptions starting from the bulk value for gallium nitride and continuing to below 300 nm. These results are consistent with a GaN particle size distribution that encompasses regions above and below the excitonic-Bohr radius of GaN, such that the GaN material shows combined bulk and quantum confined optical properties. (C) 1997 American Institute of Physics. C1 UNIV CALIF DAVIS, DEPT CHEM ENGN & MAT SCI, DAVIS, CA 95616 USA. UNIV CALIF DAVIS, DEPT MECH & AERONAUT ENGN, DAVIS, CA 95616 USA. RP LAWRENCE LIVERMORE NATL LAB, MAILSTOP L-202, LIVERMORE, CA 94550 USA. NR 25 TC 55 Z9 56 U1 0 U2 16 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 JUN 9 PY 1997 VL 70 IS 23 BP 3122 EP 3124 DI 10.1063/1.119109 PG 3 WC Physics, Applied SC Physics GA XD343 UT WOS:A1997XD34300019 ER PT J AU Bullock, M Barkigia, K Brunschwig, B Castner, E Creutz, C Chaturvedi, S Chou, M Cumming, JB Dewey, SL DiMauro, L Ding, YS Fajer, J Feldberg, S Fowler, JS Fujita, E Gushue, SE Hahn, RL Hall, G Harbottle, G Hendrey, GR Holroyd, R Haustein, P Hrbek, J Koetzle, T Larese, JZ Lee, YN Lin, M Liu, L Logan, J Lymar, S McGraw, R Muckerman, JT Newman, L Newton, M Premuzic, ET Preses, JM Reilly, J Remsberg, LP Ricci, JS Rodriguez, J Schwartz, SE Shafiq, F Shanklin, J Smalley, JF Springer, CS Sutin, N Wallace, DWR White, M Wishart, JF Wolf, AP Yan, S AF Bullock, M Barkigia, K Brunschwig, B Castner, E Creutz, C Chaturvedi, S Chou, M Cumming, JB Dewey, SL DiMauro, L Ding, YS Fajer, J Feldberg, S Fowler, JS Fujita, E Gushue, SE Hahn, RL Hall, G Harbottle, G Hendrey, GR Holroyd, R Haustein, P Hrbek, J Koetzle, T Larese, JZ Lee, YN Lin, M Liu, L Logan, J Lymar, S McGraw, R Muckerman, JT Newman, L Newton, M Premuzic, ET Preses, JM Reilly, J Remsberg, LP Ricci, JS Rodriguez, J Schwartz, SE Shafiq, F Shanklin, J Smalley, JF Springer, CS Sutin, N Wallace, DWR White, M Wishart, JF Wolf, AP Yan, S TI Brookhaven SO CHEMICAL & ENGINEERING NEWS LA English DT Letter RP Bullock, M (reprint author), BROOKHAVEN NATL LAB,LONG ISL CITY,NY, USA. RI Schwartz, Stephen/C-2729-2008; Fujita, Etsuko/D-8814-2013; Muckerman, James/D-8752-2013; Cumming, James/I-3358-2013; Wishart, James/L-6303-2013 OI Schwartz, Stephen/0000-0001-6288-310X; Cumming, James/0000-0001-6930-0958; Wishart, James/0000-0002-0488-7636 NR 0 TC 0 Z9 0 U1 0 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0009-2347 J9 CHEM ENG NEWS JI Chem. Eng. News PD JUN 9 PY 1997 VL 75 IS 23 BP 6 EP 6 PG 1 WC Chemistry, Multidisciplinary; Engineering, Chemical SC Chemistry; Engineering GA XD196 UT WOS:A1997XD19600002 ER PT J AU MacGregor, JT Wehr, CM Hiatt, RA Peters, B Tucker, JD Langlois, RG Jacob, RA Jensen, RH Yager, JW Shigenaga, MK Frei, B Eynon, BP Ames, BN AF MacGregor, JT Wehr, CM Hiatt, RA Peters, B Tucker, JD Langlois, RG Jacob, RA Jensen, RH Yager, JW Shigenaga, MK Frei, B Eynon, BP Ames, BN TI 'Spontaneous' genetic damage in man: Evaluation of interindividual variability, relationship among markers of damage, and influence of nutritional status SO MUTATION RESEARCH-FUNDAMENTAL AND MOLECULAR MECHANISMS OF MUTAGENESIS LA English DT Article DE micronucleus; folate deficiency; micronucleated erythrocyte; B-12 deficiency; chromosome damage; genetic damage; nutritional deficiency; human risk ID MICRONUCLEATED ERYTHROCYTES; SISTER CHROMATIDS; HUMANS AB The 'spontaneous' frequency of genetic damage (normal background) and the possible relationship of this damage to nutritional variables in humans were investigated in 22 subjects using several indices of genetic damage. The subjects were chosen, out of 122 initially analyzed, for being at the extremes of the highest and lowest values of one index of genetic damage, the frequency of micronucleated erythrocytes in peripheral blood. This index reflects chromosomal damage and loss in bone marrow erythropoietic cells. The assay for micronuclei is convenient but is restricted to splenectomized individuals because the human spleen removes micronucleated cells. The initial 122 subjects were splenectomized, but all were normal and healthy at the time of this study and none had a previous history of neoplastic disease. Factors investigated were stability of micronucleus frequency as a function of time, correlations among multiple markers of genetic damage, and influence on damage indices of nutritional variables, including blood levels of folate, B-12 and antioxidant vitamins. Among different individuals, the range of values was 10-fold or more in the erythrocyte micronucleus, glycophorin A, plasma ascorbate and urinary 8-hydroxydeoxyguanosine (oxo(8)dG) assays, was approximately 6-fold in the lymphocyte micronucleus assay, and was 2-fold in the lymphocyte sister chromatid exchange (SCE) assay. Red blood cell folate and plasma folate, B-12 and alpha-tocopherol values varied by up to 10-fold among individuals. Micronucleus frequencies in erythrocytes and peripheral blood lymphocytes ranged from < 0.3 to 16.9/1000 in mature red blood cells, < 1 to 33/1000 in reticulocytes, and 2.5 to 15/1000 in binucleate lymphocytes. Frequencies of glycophorin A variant erythrocytes ranged from 5.6 to 77.3 x 10(6) N/0 cells and 3.2 to 16.2 x 10(6) N/N cells, and oxo(8)dG excretion varied from 32 to 397 pmol/kg/day. Although a wide range of values was observed in each genetic endpoint, the extreme values for various endpoints of genetic damage were not observed in the same individuals. The frequency of micronucleated erythrocytes varied over time within individuals and indicated that individuals with the highest levels of damage exhibit greater variability than those with lower levels. In some subjects, frequencies of micronucleated erythrocytes changed dramatically over an interval of 2-3 years: four subjects with initial micronucleated reticulocyte frequencies of 20.4, 5.9, 6.4 and 33/1000 changed to 2.5, 20.5, 18.5 and 12/1000, respectively. Among more than 150 individuals we have studied, including the 64 individuals studied by Everson et al. [(1988) J. Natl. Cancer Inst., 80, 525-529] and Smith et al. [(1990) Cancer Res., 50, 5049-5054], the seven individuals with the highest observed frequencies of micronucleated erythrocytes all had exceptionally low values of plasma folate, red cell folate, or plasma B-12, suggesting that folate and B-12 status are the major determinants of the types of damage that lead to spontaneous micronucleus formation in erythrocytic cells. C1 UNIV CALIF BERKELEY,DIV BIOCHEM & MOL BIOL,BERKELEY,CA 94720. KAISER PERMANENTE MED CARE PROGRAM,DIV RES,OAKLAND,CA 94611. LAWRENCE LIVERMORE NATL LAB,BIOL & BIOTECHNOL RES PROGRAM,LIVERMORE,CA 94551. USDA ARS,WESTERN HUMAN NUTR RES CTR,SAN FRANCISCO,CA 94129. UNIV CALIF SAN FRANCISCO,DIV MOL CYTOMETRY,SAN FRANCISCO,CA 94103. UNIV CALIF BERKELEY,SCH PUBL HLTH,BERKELEY,CA 94720. RP MacGregor, JT (reprint author), SRI INT,333 RAVENSWOOD AVE,MENLO PK,CA 94025, USA. FU NCI NIH HHS [CA39910]; NIEHS NIH HHS [ESO1896] NR 17 TC 70 Z9 71 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0027-5107 J9 MUTAT RES-FUND MOL M JI Mutat. Res.-Fundam. Mol. Mech. Mutagen. PD JUN 9 PY 1997 VL 377 IS 1 BP 125 EP 135 DI 10.1016/S0027-5107(97)00070-5 PG 11 WC Biotechnology & Applied Microbiology; Genetics & Heredity; Toxicology SC Biotechnology & Applied Microbiology; Genetics & Heredity; Toxicology GA XG852 UT WOS:A1997XG85200016 PM 9219587 ER PT J AU Beane, SR Bernard, V Lee, TSH Meissner, UG van Kolck, U AF Beane, SR Bernard, V Lee, TSH Meissner, UG van Kolck, U TI Neutral pion photoproduction on deuterium in baryon chiral perturbation theory to order q(4) SO NUCLEAR PHYSICS A LA English DT Article ID NUCLEAR-FORCES; THRESHOLD PHOTOPRODUCTION; LAGRANGIANS; DYNAMICS AB Threshold neutral pion photoproduction on the deuteron is studied in the framework of baryon chiral perturbation theory beyond next-to-leading order in the chiral expansion. To fourth order in small momenta, the amplitude is finite and a sum of two- and three-body interactions with no undetermined parameters. With accurate theoretical and experimental input from the single nucleon sector for the proton amplitude, we investigate the sensitivity of the threshold cross section to the elementary gamma n --> pi(0)n amplitude. A precise measurement of the threshold cross section for gamma d --> pi(0)d is called for. (C) 1997 Elsevier Science B.V. C1 UNIV MARYLAND, DEPT PHYS, COLLEGE PK, MD 20742 USA. UNIV STRASBOURG 1, PHYS THEOR LAB, F-67037 STRASBOURG 2, FRANCE. ARGONNE NATL LAB, DIV PHYS, ARGONNE, IL 60439 USA. FORSCHUNGSZENTRUM JULICH, FORSCHUNGSZENTRUM, INST KERNPHYS, D-52425 JULICH, GERMANY. UNIV WASHINGTON, DEPT PHYS, SEATTLE, WA 98195 USA. RP Beane, SR (reprint author), DUKE UNIV, DEPT PHYS, DURHAM, NC 27708 USA. NR 38 TC 64 Z9 64 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 EI 1873-1554 J9 NUCL PHYS A JI Nucl. Phys. A PD JUN 9 PY 1997 VL 618 IS 4 BP 381 EP 401 DI 10.1016/S0375-9474(97)00133-4 PG 21 WC Physics, Nuclear SC Physics GA XE792 UT WOS:A1997XE79200001 ER PT J AU May, M Alburger, D Bart, S Chrien, R Sawafta, R Deutsch, M Lia, V Wissink, SW Lisantti, J Wells, SP Bowyer, SM Franklin, WA Hicks, K Clark, H Michael, R Lee, L Funsten, H Kormanyos, C Wise, J Barakat, MB Stearns, R AF May, M Alburger, D Bart, S Chrien, R Sawafta, R Deutsch, M Lia, V Wissink, SW Lisantti, J Wells, SP Bowyer, SM Franklin, WA Hicks, K Clark, H Michael, R Lee, L Funsten, H Kormanyos, C Wise, J Barakat, MB Stearns, R TI First observation of the p(Lambda)->s(Lambda) gamma-ray transition in C-13(Lambda) SO PHYSICAL REVIEW LETTERS LA English DT Article ID HYPERNUCLEI; DECAY AB The spectrum of excited states in the hypernucleus C-13(Lambda) was studied at the Brookhaven Alternate Gradient Synchrotron using the (K-, pi(-)) reaction on an enriched C-13 target. gamma rays coincident with the p(1/2 Lambda) state were observed using two large sodium iodide detectors. We interpret them as arising from the p(1/2 Lambda) --> s(1/2 Lambda) transition in C-13(Lambda). This represents the first direct observation of a gamma ray associated with the transition of a hyperon between major nuclear shells. C1 MIT,CAMBRIDGE,MA 02139. INDIANA UNIV,CYCLOTRON FACIL,BLOOMINGTON,IN 47408. OHIO UNIV,ATHENS,OH 45701. TRIUMF,VANCOUVER,BC V6T 2A3,CANADA. COLL WILLIAM & MARY,WILLIAMSBURG,VA 23187. UNIV COLORADO,BOULDER,CO 80309. UNIV HOUSTON,HOUSTON,TX 77204. VASSAR COLL,POUGHKEEPSIE,NY 12601. RP May, M (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. NR 13 TC 38 Z9 39 U1 0 U2 0 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 JUN 9 PY 1997 VL 78 IS 23 BP 4343 EP 4346 DI 10.1103/PhysRevLett.78.4343 PG 4 WC Physics, Multidisciplinary SC Physics GA XD384 UT WOS:A1997XD38400009 ER PT J AU Compton, RN Tuinman, AA Klots, CE Pederson, MR Patton, DC AF Compton, RN Tuinman, AA Klots, CE Pederson, MR Patton, DC TI Electron attachment to a negative ion: e+C-84(-)reversible arrow C-84(-2) SO PHYSICAL REVIEW LETTERS LA English DT Article ID GROUND-STATE; ANIONS; SUPERCONDUCTIVITY; C-60; C60; C84 AB The observation of sequential attachment of two electrons to the C-84 molecule and the subsequent autodetachment of the C-84 dianion is reported. Remarkably, the cross section for attaching the second electron is estimated to be of the same order as that for adding the first electron. The measured lifetime for autodetachment of C-84(-2) (similar to 60 mu sec) is in accord with calculations assuming ''thermionic emission'' from the vibrationally hot dianion. The first (EA(1)) and second (EA(2)) electron affinities of the two low-lying D-2 and D-2d isomers of C-84 are calculated using density functional theory to be +3.14 and +0.44 eV, respectively. C1 UNIV TENNESSEE,DEPT PHYS,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,CHEM PHYS SECT,OAK RIDGE,TN 37831. USN,RES LAB,WASHINGTON,DC 20375. RP Compton, RN (reprint author), UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996, USA. NR 24 TC 97 Z9 97 U1 1 U2 6 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 JUN 9 PY 1997 VL 78 IS 23 BP 4367 EP 4370 DI 10.1103/PhysRevLett.78.4367 PG 4 WC Physics, Multidisciplinary SC Physics GA XD384 UT WOS:A1997XD38400015 ER PT J AU Liu, YM Ecke, RE AF Liu, YM Ecke, RE TI Eckhaus-Benjamin-Feir instability in rotating convection SO PHYSICAL REVIEW LETTERS LA English DT Article ID RAYLEIGH-BENARD CONVECTION; ASYMMETRIC MODES; WAVES; STATES AB We report experimental measurements of a traveling-wave state in rotating Rayleigh-Benard convection. The fluid was water with a Prandtl number of 6.3 and a dimensionless rotation rate of 274. The marginal and Eckhaus-Benjamin-Feir stability boundaries were determined and the local amplitude and wave number were obtained from demodulation of shadowgraph images. The phase-diffusion coefficient and group velocity were measured in the stable wave number band. This system was found to be well described by the one-dimensional complex Ginzburg-Landau equation. C1 LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES,LOS ALAMOS,NM 87545. RP Liu, YM (reprint author), LOS ALAMOS NATL LAB,CONDENSED MATTER & THERMAL PHYS GRP,POB 1663,LOS ALAMOS,NM 87545, USA. OI Ecke, Robert/0000-0001-7772-5876 NR 17 TC 28 Z9 28 U1 0 U2 3 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 JUN 9 PY 1997 VL 78 IS 23 BP 4391 EP 4394 DI 10.1103/PhysRevLett.78.4391 PG 4 WC Physics, Multidisciplinary SC Physics GA XD384 UT WOS:A1997XD38400021 ER PT J AU Liu, X White, BE Pohl, RO Iwanizcko, E Jones, KM Mahan, AH Nelson, BN Crandall, RS Veprek, S AF Liu, X White, BE Pohl, RO Iwanizcko, E Jones, KM Mahan, AH Nelson, BN Crandall, RS Veprek, S TI Amorphous solid without low energy excitations SO PHYSICAL REVIEW LETTERS LA English DT Article ID SILICON; GLASSES; FILMS AB We have measured the low temperature internal friction (Q(-1)) of amorphous silicon (a-Si) films. e-beam evaporation or Si-28(+) implantation leads to the temperature-independent Q(0)(-1) plateau common to all amorphous solids. For hydrogenated amorphous silicon with 1 at. %H produced by hot wire chemical vapor deposition, however, Q(0)(-1) is over 200 times smaller than for e-beam a-Si. This is the first observation of an amorphous solid without any significant low energy excitations. It offers the opportunity to study amorphous solids containing controlled densities of tunneling defects, and thus to explore their nature. C1 NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401. TECH UNIV MUNICH,INST CHEM INORGAN MAT,D-85747 GARCHING,GERMANY. RP Liu, X (reprint author), CORNELL UNIV,ATOM & SOLID STATE PHYS LAB,ITHACA,NY 14853, USA. RI Veprek, Stan/C-1248-2008 OI Veprek, Stan/0000-0002-6016-3093 NR 21 TC 127 Z9 129 U1 0 U2 6 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 JUN 9 PY 1997 VL 78 IS 23 BP 4418 EP 4421 DI 10.1103/PhysRevLett.78.4418 PG 4 WC Physics, Multidisciplinary SC Physics GA XD384 UT WOS:A1997XD38400028 ER PT J AU Wang, LS Nicholas, JB Dupuis, M Wu, HB Colson, SD AF Wang, LS Nicholas, JB Dupuis, M Wu, HB Colson, SD TI Si3Oy (y=1-6) clusters: Models for oxidation of silicon surfaces and defect sites in bulk oxide materials SO PHYSICAL REVIEW LETTERS LA English DT Article ID MOLECULAR-ORBITAL METHODS; AMORPHOUS SIO2; DIOXIDE; OXYGEN; GLASS; PHOTOLUMINESCENCE; LUMINESCENCE; INTERFACE; CENTERS AB We studied the structure and bonding of a series of silicon oxide clusters, Si3Oy (y = 1-6), using anion photoelectron spectroscopy and ab initio calculations. For y = 1-3 the clusters represent the sequential oxidation of Si-3, and provide structural models for the oxidation of silicon surfaces. For y = 4-6, the clusters contain a central Si in a tetrahedral bonding environment, suggesting the onset of the bulklike structure. Evidence is presented that suggests the Si3O4 cluster (D-2d) may provide a structural model for oxygen-deficient defect sites in bulk SiO2 materials. C1 PACIFIC NW LAB, ENVIRONM MOL SCI LAB, RICHLAND, WA 99352 USA. RP Wang, LS (reprint author), WASHINGTON STATE UNIV, DEPT PHYS, RICHLAND, WA 99352 USA. NR 36 TC 101 Z9 106 U1 2 U2 13 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 JUN 9 PY 1997 VL 78 IS 23 BP 4450 EP 4453 DI 10.1103/PhysRevLett.78.4450 PG 4 WC Physics, Multidisciplinary SC Physics GA XD384 UT WOS:A1997XD38400036 ER PT J AU Stumpf, R AF Stumpf, R TI H-induced reconstruction and faceting of Al surfaces SO PHYSICAL REVIEW LETTERS LA English DT Article ID MOLECULAR-BEAM EPITAXY; HYDROGEN ADSORPTION; DIFFUSION; AL(111); ALUMINUM; GROWTH; DEPENDENCE; DESORPTION; KINETICS; AL(100) AB First principles calculations show that chemisorbed H causes vacancy reconstructions and faceting of all Al low index surfaces. On Al(111) H-decorated vacancies are stable; on H-covered Al(100) vacancies are easily activated thermally. H-covered Al(110) forms a missing row reconstruction with H-decorated vacancies on the {111} microfacets. At high H coverages, low index Al surfaces are unstable against faceting. Al(111) and Al(110) form {211} facets, on Al(100) islands and pits with {311} and {211} facets are stable. The H-induced structural changes are caused by the preferential binding of H at low coordinated Al surface atoms and at (100) microfacets or, more generally, at ''surface tetrahedral'' sites. RP Stumpf, R (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 26 TC 49 Z9 49 U1 2 U2 8 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 JUN 9 PY 1997 VL 78 IS 23 BP 4454 EP 4457 DI 10.1103/PhysRevLett.78.4454 PG 4 WC Physics, Multidisciplinary SC Physics GA XD384 UT WOS:A1997XD38400037 ER PT J AU DeYoreo, JJ Land, TA Lee, JD AF DeYoreo, JJ Land, TA Lee, JD TI Limits on surface vicinality and growth rate due to hollow dislocation cores on KDP {101} SO PHYSICAL REVIEW LETTERS LA English DT Article ID ATOMIC-FORCE MICROSCOPY; BY-LAYER GROWTH; CRYSTAL-GROWTH; EPITAXIAL-GROWTH; MORPHOLOGY; MECHANISMS; SIZE; FACE AB Atomic-force microscopy measurements on KDP {101} faces are presented which show that the terrace width W on vicinal dislocation growth hillocks is nearly independent of supersaturation sigma and Burgers vector b, in contradiction to simple Burton-Cabrera-Frank models. An analytical model taking into account the effect of dislocation cores on step rotation is presented which predicts a dependence of W on sigma and b, in good agreement with the measurements. Using these results, we rescale macroscopic growth rate data onto a single Arrhenius curve, which gives a value of 0.33 eV for the activation energy of step motion. RP DeYoreo, JJ (reprint author), LAWRENCE LIVERMORE NATL LAB,DEPT CHEM & MAT SCI,LIVERMORE,CA 94550, USA. NR 21 TC 52 Z9 52 U1 0 U2 8 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 JUN 9 PY 1997 VL 78 IS 23 BP 4462 EP 4465 DI 10.1103/PhysRevLett.78.4462 PG 4 WC Physics, Multidisciplinary SC Physics GA XD384 UT WOS:A1997XD38400039 ER PT J AU Zhang, SW Carlson, J Gubernatis, JE AF Zhang, SW Carlson, J Gubernatis, JE TI Pairing correlations in the two-dimensional Hubbard model SO PHYSICAL REVIEW LETTERS LA English DT Article ID SYSTEMS AB We present the results of a quantum Monte Carlo study of the extended s and the d(x2-y2) pairing correlation functions for the two-dimensional Hubbard model, computed with the constrained-path Monte Carlo method. For small lattice sizes and weak interactions, we find that the d(x2-y2) pairing correlations are stronger than the extended s pairing correlations and are positive when the pair separation exceeds several lattice constants. As the system size or the interaction strength increases, the magnitude of the long-range part of both correlation functions vanishes. C1 OHIO STATE UNIV, DEPT PHYS, COLUMBUS, OH 43210 USA. LOS ALAMOS NATL LAB, DIV THEORET, LOS ALAMOS, NM 87545 USA. NR 14 TC 120 Z9 122 U1 2 U2 4 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JUN 9 PY 1997 VL 78 IS 23 BP 4486 EP 4489 DI 10.1103/PhysRevLett.78.4486 PG 4 WC Physics, Multidisciplinary SC Physics GA XD384 UT WOS:A1997XD38400045 ER PT J AU Pecharsky, VK Gschneidner, KA AF Pecharsky, VK Gschneidner, KA TI Giant magnetocaloric effect in Gd-5(Si2Ge2) SO PHYSICAL REVIEW LETTERS LA English DT Article AB An extremely large magnetic entropy change has been discovered in Gd-5(Si2Ge2) when subjected to a change in the magnetic field. It exceeds the reversible (with respect to an alternating magnetic field) magnetocaloric effect in any known magnetic material by at least a factor of 2, and it is due to a first order [ferromagnetic (I) <-> ferromagnetic (II)] phase transition at 276 K and its unique magnetic field dependence. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT MAT SCI & ENGN,AMES,IA 50011. RP Pecharsky, VK (reprint author), IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011, USA. NR 14 TC 2292 Z9 2394 U1 26 U2 246 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 JUN 9 PY 1997 VL 78 IS 23 BP 4494 EP 4497 DI 10.1103/PhysRevLett.78.4494 PG 4 WC Physics, Multidisciplinary SC Physics GA XD384 UT WOS:A1997XD38400047 ER PT J AU Elphick, C Hagberg, A Malomed, BA Meron, E AF Elphick, C Hagberg, A Malomed, BA Meron, E TI On the origin of traveling pulses in bistable systems SO PHYSICS LETTERS A LA English DT Article ID COMMENSURATE-INCOMMENSURATE TRANSITION; REACTION-DIFFUSION-SYSTEMS; ROTATING MAGNETIC-FIELD; NONEQUILIBRIUM SYSTEMS; FRONT BIFURCATIONS; PATTERN-FORMATION; LIQUID-CRYSTALS; CONVECTION; BREAKING; WAVES AB The interaction between a pair of Bloch fronts forming a traveling domain in a bistable medium is studied. A parameter range beyond the nonequilibrium Ising-Bloch bifurcation is found where traveling domains collapse. Only beyond a second threshold the repulsive front interactions become strong enough to balance attractive interactions and asymmetries in front speeds, and form stable traveling pulses, The analysis is carried out for the forced complex Ginzburg-Landau equation. Similar qualitative behavior is found in the bistable FitzHugh-Nagumo model. (C) 1997 Published by Elsevier Science B.V. C1 LOS ALAMOS NATL LAB, CTR NONLINEAR STUDIES & T7, DIV THEORET, LOS ALAMOS, NM 87545 USA. TEL AVIV UNIV, FAC ENGN, DEPT INTERDISCIPLINARY STUDIES, IL-69978 RAMAT AVIV, ISRAEL. BEN GURION UNIV NEGEV, JACOB BLAUSTEIN INST DESERT RES, IL-84990 SEDE BOQER, ISRAEL. BEN GURION UNIV NEGEV, DEPT PHYS, IL-84990 SEDE BOQER, ISRAEL. RP Elphick, C (reprint author), CTR FIS NO LINEAL & SISTEMAS COMPLEJOS SANTIAGO, CASILLA 17122, SANTIAGO, CHILE. RI MERON, EHUD/F-1810-2012 NR 31 TC 36 Z9 36 U1 1 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9601 J9 PHYS LETT A JI Phys. Lett. A PD JUN 9 PY 1997 VL 230 IS 1-2 BP 33 EP 37 DI 10.1016/S0375-9601(97)00228-4 PG 5 WC Physics, Multidisciplinary SC Physics GA XE786 UT WOS:A1997XE78600006 ER PT J AU Shiang, JJ Wolters, RH Heath, JR AF Shiang, JJ Wolters, RH Heath, JR TI Theory of size-dependent resonance Raman intensities in InP nanocrystals SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID CDSE QUANTUM DOTS; SEMICONDUCTOR CLUSTERS; ELECTRONIC-STRUCTURE; PHONON COUPLINGS; GLASS MATRIX; SCATTERING; POTENTIALS; MICROCRYSTALS; SPECTROSCOPY; ABSORPTION AB The resonance Raman spectrum of InP nanocrystals is characterized by features ascribable to both longitudinal (LO) and transverse (TO) optical modes. The intensity ratio of these modes exhibits a strong size dependence. To calculate the size dependence of the LO and TO Raman cross sections, we combine existing models of Raman scattering, the size dependence of electronic and vibrational structure, and electron vibration coupling in solids. For nanocrystals with a radius >10 Angstrom, both the LO and TO coupling strengths increase with increasing radius. This, together with an experimentally observed increase in the electronic dephasing rate with decreasing size, allows us to account for the observed ratio of LO/TO Raman intensities. (C) 1997 American Institute of Physics. C1 UNIV CALIF LOS ANGELES,DEPT CHEM & BIOCHEM,LOS ANGELES,CA 90095. LAWRENCE BERKELEY LAB,INST MOL DESIGN,BERKELEY,CA 94720. NR 52 TC 20 Z9 20 U1 1 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 JUN 8 PY 1997 VL 106 IS 22 BP 8981 EP 8994 DI 10.1063/1.474031 PG 14 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA XB879 UT WOS:A1997XB87900005 ER PT J AU Asher, RL Appelman, EH Tilson, JL Litorja, M Berkowitz, J Ruscic, B AF Asher, RL Appelman, EH Tilson, JL Litorja, M Berkowitz, J Ruscic, B TI A photoionization study of trifluoromethanol, CF3OH, trifluoromethyl hypofluorite, CF3OF, and trifluoromethyl hypochlorite, CF3OCl SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID GAS-PHASE BASICITIES; AB-INITIO; ATMOSPHERIC CHEMISTRY; ABSTRACTION REACTIONS; HYDROGEN-FLUORIDE; BOND-ENERGY; RADICALS; HEATS; THERMOCHEMISTRY; DECOMPOSITION AB CF3OH, an important and controversial by-product of atmospheric decomposition of CF3CFH2 (HFC-134a) and other hydrofluorocarbons, has been examined by photoionization mass spectrometry. The ionization onset is characterized by a broad Franck-Condon distribution, arising primarily from a substantial elongation of the C-O bond upon ionization. An upper limit to the adiabatic ionization potential (IP) of less than or equal to 13.08+/-0.05 eV has been established. The appearance potentials (APs) of the first two fragments have been accurately determined by fitting with appropriate model functions as AP(0)(CF2OH+/CF3OH)less than or equal to 13.830+/-0.005 eV and AP(0)(CF3+/CF3OH)less than or equal to 13.996+/-0.005 eV. While the exact nature of the lowest-energy fragment (nominally CF2OH+) is not clear, the CF3+ fragment threshold leads unambiguously to Delta H(f 298)degrees(CF3OH)greater than or equal to 217.2+/-0.9 kcal/mol and D-298(CF3-OH)less than or equal to 115.2+/-0.3 kcal/mol. With previously derived Delta H(f 298)degrees(CF3O)=-151.8(-1.1)(+1.7) kcal/mol, this yields D-298(CF3O-H)=117.5(-1.4)(+1.9) kcal/mol, very close to, or only slightly weaker than the O-H bond energy in water: D-298(CF3O-H)-D-298(HO-H)=-1.8(-1.4)(+1.9) kcal/mol approximate to 0 kcal/mol. Similarly, with the recently redetermined value for Delta H degrees(CF2O), this implies a 298 K reaction enthalpy for the 1,2-elimination of HF from CF3OH of 2.8(-1.1)(+1.7) kcal/mol. CF3OF and CF3OCl have also been examined by photoionization ionization. CF3OF produces a very weak parent, with an apparent adiabatic IP(CF3OF)less than or equal to 12.710+/-0.007 eV. An analysis of the CF3+ and CF2O+ fragments from CF3OF, when combined with literature data, suggests Delta H(f 298)degrees(CF3OF)=-176.9+/-1.8 kcal/mol. The fitted value for the appearance potential of CF3+ from CF3OCl, AP(0)(CF3+/CF3OCl)less than or equal to 12.85+/-0.01 eV, leads to Delta H(f 298)degrees(CF3OCl)greater than or equal to-175.6+/-1.0 kcal/mol, D-298(CF3-OCl)less than or equal to 88.4+/-0.3 kcal/mol, and D-298(CF3O-Cl)less than or equal to 52.8(-1.5)(+2.0) kcal/mol. (C) 1997 American Institute of Physics. RP Asher, RL (reprint author), ARGONNE NATL LAB,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Ruscic, Branko/A-8716-2008 OI Ruscic, Branko/0000-0002-4372-6990 NR 65 TC 20 Z9 20 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 JUN 8 PY 1997 VL 106 IS 22 BP 9111 EP 9121 DI 10.1063/1.474017 PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA XB879 UT WOS:A1997XB87900018 ER EF