FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Moore, GT Koch, K Dearborn, ME Vaidyanathan, M AF Moore, GT Koch, K Dearborn, ME Vaidyanathan, M TI A simultaneously phase-matched tandem optical parametric oscillator SO IEEE JOURNAL OF QUANTUM ELECTRONICS LA English DT Article DE nonlinear optics; optical frequency conversion; optical mixers; optical mixing; optical parametric oscillators AB We report the theoretical analysis of simultaneously phase-matched tandem optical parametric oscillator (STOPO) in which the principal OPO generates a signal which pumps a secondary OPO, Both OPO interactions are assumed to be phase-matched in a single crystal. The cavity has high Q for the signal produced by the principal OPO and has lower Q for the signal of the secondary OPO, The pump and the two idler frequencies are not resonated. The five craves undergoing nonlinear mixing are assumed to be nondegenerate in either frequency or polarization. We show that the useful output, consisting of the two idlers and the signal of the secondary OPO, can be produced with high efficiency over a large dynamic range in the pump intensity. We discuss the tuning with temperature and grating period of a STOPO based on periodically poled LiNbO3 pumped at 1.064 mu m. We present results based on both plane-wave modeling and modeling in three spatial dimensions. C1 USAF, Res Lab, Solid State Laser & Nonlinear Opt Branch, AFRL DELO, Kirtland AFB, NM 87117 USA. Univ New Mexico, Ctr Adv Studies, Albuquerque, NM 87131 USA. Univ New Mexico, Dept Phys & Astron, Albuquerque, NM 87131 USA. USAF, Res Lab, Sensors Directorate, Wright Patterson AFB, OH 45433 USA. RP Moore, GT (reprint author), USAF, Res Lab, Solid State Laser & Nonlinear Opt Branch, AFRL DELO, Kirtland AFB, NM 87117 USA. NR 12 TC 9 Z9 9 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9197 J9 IEEE J QUANTUM ELECT JI IEEE J. Quantum Electron. PD MAY PY 1998 VL 34 IS 5 BP 803 EP 810 DI 10.1109/3.668767 PG 8 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA ZJ412 UT WOS:000073212900009 ER PT J AU Abare, AC Mack, MP Hansen, M Sink, RK Kozodoy, P Keller, S Speck, JS Bowers, JE Mishra, UK Coldren, LA DenBaars, SP AF Abare, AC Mack, MP Hansen, M Sink, RK Kozodoy, P Keller, S Speck, JS Bowers, JE Mishra, UK Coldren, LA DenBaars, SP TI Cleaved and etched facet nitride laser diodes SO IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS LA English DT Article DE blue; diode; InGaN; GaN; laser; nitride; MQW; pulsed; room temperature AB Room-temperature (RT) pulsed operation of blue (420 mm) nitride-based multiquantum-well laser diodes grown on a-plane and c-plane sapphire substrates has been demonstrated. Structures investigated include etched and cleaved facets as well as doped and undoped quantum wells. A combination of atmospheric and low-pressure metal organic chemical vapor deposition using a modified two-flow horizontal reactor was employed. Threshold current densities as low as 12.6 kA/cm(2) were observed for 10 x 1200 mu m lasers with uncoated reactive ion etched facets on c-plane sapphire, Cleaved facet lasers were also demonstrated with similar performance on a-plane sapphire. Laser diodes tested under pulsed conditions operated up to 6 h at RT, Lasing was achieved up to 95 degrees C and up to a 150-ns pulselength (RT), Threshold current increased with temperature with a characteristic temperature T-0 of 114 K. C1 Univ Calif Santa Barbara, Dept Elect & Comp Engn, Santa Barbara, CA 93106 USA. Univ Calif Santa Barbara, Dept Mat, Santa Barbara, CA 93106 USA. USAF, Wright Lab, Wright Patterson AFB, OH 45433 USA. RP Abare, AC (reprint author), Univ Calif Santa Barbara, Dept Elect & Comp Engn, Santa Barbara, CA 93106 USA. RI Speck, James/H-5646-2011; Bowers, John/B-3486-2012 OI Bowers, John/0000-0003-4270-8296 NR 11 TC 12 Z9 12 U1 0 U2 6 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1077-260X J9 IEEE J SEL TOP QUANT JI IEEE J. Sel. Top. Quantum Electron. PD MAY-JUN PY 1998 VL 4 IS 3 BP 505 EP 509 DI 10.1109/2944.704109 PG 5 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA 103MC UT WOS:000075158800005 ER PT J AU Morkoc, H AF Morkoc, H TI Wurtzite GaN-based heterostructures by molecular beam epitaxy SO IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS LA English DT Article DE detectors; epitaxial growth; gallium components; light-emitting diodes; semiconductor heterojunctions ID MG-DOPED GAN; LIGHT-EMITTING-DIODES; GALLIUM NITRIDE; ULTRAVIOLET DETECTORS; THIN-FILMS; SOURCE MBE; GROWTH; SAPPHIRE; BLUE; SILICON AB Progress in plasma and reactive molecular beam epitaxy (PMBE and RMBE) grown n- and p-type GaN and GaN-AlGaN-based epitaxial films and optoelectronic devices is reviewed. The growth of GaN by RMBE (PMBE) is achieved by employing ammonia gas (plasma activated nitrogen) as the nitrogen source with resultant growth rates of about 2 mu m/h (greater than or equal to 1 mu m/h). The structural, electrical, and optical properties of binary and ternary (Al,Ga)N and (In,Ga)N layers point to high quality. The GaN layers with Mg as the dopant atoms are p-type without any postgrowth treatment, but the hole concentrations are limited to mid 10(17) cm(-3) although reports in the low 10(18) cm(-3) dot the literature. The background carrier concentration, mobility, optical characteristics and ability to dope p-type depend significantly on the substrate temperature and V-III ratio employed. AlGaN-GaN, and GaN-InGaN electroluminescent devices have been realized but lack commercial quality. The AlGaN-GaN photodiodes by RMBE exhibited a maximum zero-bias responsivity of 0.12 A/W at 364 mn, which decreased by more than three orders of magnitude for wavelengths longer than 390 mn. A reverse bias of -10 V raised the responsivity to 0.15 A/W without any significant increase in noise. The noise equivalent noise power hear zero bias is below the detection limit of the measurement setup. At a reverse bias of 28 V, the total noise equivalent power is 2.06 x 10(-11) W. C1 Virginia Commonwealth Univ, Dept Elect Engn, Richmond, VA 23284 USA. USAF, Res Labs, Washington, DC USA. RP Morkoc, H (reprint author), Virginia Commonwealth Univ, Dept Elect Engn, Richmond, VA 23284 USA. NR 79 TC 28 Z9 28 U1 3 U2 10 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1077-260X J9 IEEE J SEL TOP QUANT JI IEEE J. Sel. Top. Quantum Electron. PD MAY-JUN PY 1998 VL 4 IS 3 BP 537 EP 549 DI 10.1109/2944.704115 PG 13 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA 103MC UT WOS:000075158800011 ER PT J AU Altshuler, EE AF Altshuler, EE TI Tropospheric range-error corrections for the global positioning system SO IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION LA English DT Article DE global positioning system AB The global positioning system (GPS) is a highly accurate navigation system that has a broad spectrum of military, civilian, and commercial applications. It uses a triangulation scheme based on the time delays of signals from the satellites to the user; these time delays are then equated to distances. However, as the timing signal passes through the earth's atmosphere it undergoes an additional time delay due to the index of refraction, The time delay produced by the troposphere approaches a value corresponding to a range error of about 25 m for an elevation angle of 5 degrees and decreases with increasing elevation angle to less than a few meters at zenith. It has been shown that there is a good correlation between the range error and the surface index of refraction, Worldwide statistics of surface refractivity have been analyzed and shown to be correlated with site latitude, height above sea level, and time of year. Regression lines for range-error corrections based on these parameters are derived. Range-error accuracies vary from about 8% down to 3.7% of the total range error, depending on the amount of information that is available. C1 USAF, Res Lab, Electromagnet & Reliabil Directorate, Hanscom AFB, MA 01731 USA. RP Altshuler, EE (reprint author), USAF, Res Lab, Electromagnet & Reliabil Directorate, Hanscom AFB, MA 01731 USA. NR 14 TC 13 Z9 13 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-926X J9 IEEE T ANTENN PROPAG JI IEEE Trans. Antennas Propag. PD MAY PY 1998 VL 46 IS 5 BP 643 EP 649 DI 10.1109/8.668906 PG 7 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA ZJ759 UT WOS:000073250100007 ER PT J AU Pyati, VP AF Pyati, VP TI Comment on "On the geometry of parallel impedances" SO IEEE TRANSACTIONS ON EDUCATION LA English DT Letter C1 USAF, Inst Technol, Dept Elect & Comp Engn, Wright Patterson AFB, OH 45433 USA. RP Pyati, VP (reprint author), USAF, Inst Technol, Dept Elect & Comp Engn, Wright Patterson AFB, OH 45433 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9359 J9 IEEE T EDUC JI IEEE Trans. Educ. PD MAY PY 1998 VL 41 IS 2 BP 171 EP 171 DI 10.1109/13.669728 PG 1 WC Education, Scientific Disciplines; Engineering, Electrical & Electronic SC Education & Educational Research; Engineering GA ZL612 UT WOS:000073451800012 ER PT J AU Shaw, JJ McCleskey, FK Beninga, KK Candler, W Redkar, RJ DelVecchio, VG Goode, MT AF Shaw, JJ McCleskey, FK Beninga, KK Candler, W Redkar, RJ DelVecchio, VG Goode, MT TI Rapid detection of tularemia with real-time PCR SO INFECTIONS IN MEDICINE LA English DT Article DE tularemia; Francisella tularensis; polymerase chain reaction (PCR); ciprofloxacin; doxycycline ID FRANCISELLA-TULARENSIS AB The laboratory diagnosis of tularemia can pose serious risks to microbiologic personnel, and cultures can take days to grow Francisella tularensis. The use of a real-time PCR assay can shorten diagnosis time to hours. This approach may gain greater importance if this bacterial agent is used in biologic warfare. C1 AOEL, Armstrong Lab, Brooks AFB, TX 78283 USA. RP Shaw, JJ (reprint author), AOEL, Armstrong Lab, Brooks AFB, TX 78283 USA. NR 22 TC 3 Z9 3 U1 0 U2 0 PU SCP COMMUNICATIONS INC PI NEW YORK PA 134 W 29TH ST, NEW YORK, NY 10001-5304 USA SN 0749-6524 J9 INFECT MED JI Infect. Med. PD MAY PY 1998 VL 15 IS 5 BP 326 EP 330 PG 5 WC Infectious Diseases SC Infectious Diseases GA ZP808 UT WOS:000073790500010 ER PT J AU Vinegar, A Jepson, GW Overton, JH AF Vinegar, A Jepson, GW Overton, JH TI PBPK modeling of short-term (0 to 5 min) human inhalation exposures to halogenated hydrocarbons SO INHALATION TOXICOLOGY LA English DT Article ID ISOFLURANE; DESFLURANE; HALOTHANE; HCFC-123; KINETICS; RAT AB Allowable human exposure to Halons and Halon replacement chemicals is often regulated on the basis of cardiac sensitization potential. Exposure guidelines are established using dose-response data obtained from animal testing. Results from animal tests are often summarized by no-observable-adverse-effect level and lowest-observable-adverse-effect level values. This threshold approach alone does not provide the information necessary to evaluate the cardiac sensitization potential for the chemical of interest under a variety of exposure concentrations and durations. In order to provide a tool for decision makers and regulators tasked with setting exposure guidelines for Halon replacement chemicals, a quantitative approach was established that allows exposures to be assessed in terms of the chemical concentrations in blood during the exposure. A physiologically based pharmacokinetic model was modified to include a respiratory-tract compartment containing a dead-space region and a pulmonary exchange area. The pulmonary exchange area had its own air space, tissue, and capillary subregions. Refinement of the model to include a breath-by-breath description of respiratory-tract uptake allowed successful simulation of exhaled breath concentrations during the first minute of exposure to the anesthetics halothane, isoflurane, and desflurane. The model has been applied successfully to an actual case of accidental exposure to Halon 1211 during extinguishment of a fire in a military armored vehicle. This model ultimately will be useful in simulating various short-term exposure scenarios for better evaluation of safe use of Halon replacement chemicals. C1 Mantech Environm Technol Inc, Dayton, OH 45437 USA. USAF, Div Toxicol, Armstrong Lab, Wright Patterson AFB, OH 45433 USA. US EPA, Expt Toxicol Div, Pulm Toxicol Branch, Res Triangle Pk, NC 27711 USA. RP Vinegar, A (reprint author), Mantech Environm Technol Inc, POB 31009, Dayton, OH 45437 USA. EM vinegara@falcon.al.wpafb.af.mil NR 15 TC 11 Z9 11 U1 0 U2 0 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 0895-8378 J9 INHAL TOXICOL JI Inhal. Toxicol. PD MAY PY 1998 VL 10 IS 5 BP 411 EP 429 DI 10.1080/089583798197600 PG 19 WC Toxicology SC Toxicology GA ZR976 UT WOS:000074035200002 ER PT J AU Armstrong, RA Shorter, JA Taylor, MJ Suszcynsky, DM Lyons, WA Jeong, LS AF Armstrong, RA Shorter, JA Taylor, MJ Suszcynsky, DM Lyons, WA Jeong, LS TI Photometric measurements in the SPRITES '95 & '96 campaigns of nitrogen second positive (399.8 nm) and first negative (427.8 nm) emissions SO JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS LA English DT Article ID IONIZATION; BAND; STRATOSPHERE; EXCITATION; DISCHARGES; AIRCRAFT AB We have obtained blue photometric measurements of the N-2 second positive 399.8 nm and the N-2(+) first negative 427.8 nm emission from sprites, elves and lightning, along with supporting video images. The pulse width and intensity results for sprites are consistent with those of Suszcynsky et al. (1998). The red emission from sprites has been independently and unambiguously identified by Hampton et al. (1996) and Mende et al. (1995) as the nitrogen first positive band. The source has been attributed to electron impact excitation from low energy electrons(approximate to 1 eV) in the sprite. The short pulse width of the 427.8 nm and 399.8 nm photometer rime traces obtained in this investigation are probably not from the same source that produces the red emission. The results reported here indicate an initial energetic ionizing event sufficient to ionize and excite nitrogen followed by secondary electron processes which give rise to the dominant red emission. The photometer results for elves are consistent with the EMP mechanism suggested by Inan et al. (1996). The photometer traces obtained for lightning indicate emissions consistent with a 'continuing current' as the charge redistributes within the thunderstorm cloud. We find that the ratio of the intensity of the 399.8 nm N-2(2P) emission to that of 427.8 nm N-2(+) (1N) emission can be used to discriminate among sprites, elves and lightning. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 Mission Res Corp, Nashua, NH 03062 USA. Utah State Univ, Logan, UT 84332 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. FMA Res, Ft Collins, CO 80524 USA. USAF, Phillips Lab, GPOS, Hanscom AFB, MA 01731 USA. RP Armstrong, RA (reprint author), Mission Res Corp, 1 Tara Blvd, Nashua, NH 03062 USA. NR 42 TC 50 Z9 50 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1364-6826 J9 J ATMOS SOL-TERR PHY JI J. Atmos. Sol.-Terr. Phys. PD MAY-JUN PY 1998 VL 60 IS 7-9 BP 787 EP 799 DI 10.1016/S1364-6826(98)00026-1 PG 13 WC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences SC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences GA 124QP UT WOS:000076193500014 ER PT J AU He, ZG Spain, JC AF He, ZG Spain, JC TI A novel 2-Aminomuconate deaminase in the nitrobenzene degradation pathway of Pseudomonas pseudoalcaligenes JS45 SO JOURNAL OF BACTERIOLOGY LA English DT Article ID 4-OXALOCROTONATE TAUTOMERASE; META-CLEAVAGE; ENZYMATIC KETONIZATION; 2-HYDROXYMUCONATE; METABOLISM; MECHANISM; CATECHOL; ACID AB 2-Aminomuconate, an intermediate in the metabolism of tryptophan in mammals, is also an intermediate in the biodegradation of nitrobenzene by Pseudomonas pseudoalcaligenes JS45. Strain JS45 hydrolyzes 2-aminomuconate to 4-oxyalocrotonic acid, with the release of ammonia, which senses as the nitrogen source for growth of the microorganism. As an initial step in studying the novel deamination mechanism, we report here the purification and some properties of 2-aminomuconate deaminase, The purified enzyme migrates as a single band with a molecular mass of 16.6 kDa in 15% polyacrylamide gel electrophoresis under denaturing conditions. The estimated molecular mass of the native enzyme was 100 kDa by gel filtration and 4 to 20% gradient nondenaturing polyacrylamide gel electrophoresis, suggesting that the enzyme consists of six: identical subunits. The enzyme was stable at room temperature and exhibited optimal activity at pH 6.6. The K-m for 2-aminomuconate was approximately 67 mu M, and the V-max was 125 mu mol.min(-1) mg(-1). The N-terminal amino acid sequence of the enzyme did not shelf any significant similarity to any sequence in the databases. The purified enzyme converted 2-aminomuconate directly to 4-oxalocrotonate, rather than 2-hydroxymuconate, which suggests that the deamination was carried out via an imine intermediate. C1 AFRL, MLQR, Tyndall AFB, FL 32403 USA. RP AFRL, MLQR, Bldg 1117,139 Barnes Dr, Tyndall AFB, FL 32403 USA. EM jspain@ccmail.aleq.tyndall.af.mil OI He, Zhongqi/0000-0003-3507-5013 NR 23 TC 31 Z9 37 U1 0 U2 6 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1752 N ST NW, WASHINGTON, DC 20036-2904 USA SN 0021-9193 EI 1098-5530 J9 J BACTERIOL JI J. Bacteriol. PD MAY PY 1998 VL 180 IS 9 BP 2502 EP 2506 PG 5 WC Microbiology SC Microbiology GA ZK570 UT WOS:000073338400031 PM 9573204 ER PT J AU Bruno, JG Parker, JE Holwitt, E Alls, JL Kiel, JL AF Bruno, JG Parker, JE Holwitt, E Alls, JL Kiel, JL TI Preliminary electrochemiluminescence studies of metal ion-bacterial diazoluminomelanin (DALM) interactions SO JOURNAL OF BIOLUMINESCENCE AND CHEMILUMINESCENCE LA English DT Article DE electrochemiluminescence; metals; melanins; luminol; binding ID LUMINOL; SAMPLES; SPORES AB Electrochemiluminescence (ECL) studies of the chemiluminescent (CL) polymer diazoluminomelanin (DALM) biosynthesized in nitrate reductase transfected Escherichia coli JM109 bacteria revealed noteworthy anodic ECL and even more intense cathodic ECL. Bacterial BALM (BD) ECL was also assessed in the presence of 100 ppm of 33 different metal and non-metal ions which revealed specific anodic, but not cathodic, enhancements of ED ECL with Ag+, Hg2+ and Ru3+. The precursors and intermediate polymers which comprise CALM, such as luminol, 3-amino-L-tyrosine (3-AT), aminomelanin (AM) and diazomelanin (DM) were screened for ECL enhancement against the same set of elemental ions. Significant anodic ECL enhancements were observed for luminol with Hg2+ in the presence of tripropylamine (TPA), but not for any other DALM component in combination with other elemental ions, either anodically or cathodically. Comparison of ED with luminol in the presence and absence of TPA and Hg2+ revealed very different ECL activity patterns and suggested different mechanisms for ED and luminol ECL. (C) 1998 John Wiley & Sons, Ltd. C1 Univ Texas, Hlth Sci Ctr, Dept Radiol, San Antonio, TX 78284 USA. USAF, Res Lab, Human Effectiveness Directorate, Directed Energy Bioeffects Div, Brooks AFB, TX 78235 USA. RP Kiel, JL (reprint author), USAF, Res Lab, Human Effectiveness Directorate, Energy Bioeffects Div, 2503 Gillingham Dr, Brooks AFB, TX 78235 USA. NR 23 TC 7 Z9 8 U1 0 U2 5 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0884-3996 J9 J BIOLUM CHEMILUM JI J. Biolumin. Chemilumin. PD MAY-JUN PY 1998 VL 13 IS 3 BP 117 EP 123 DI 10.1002/(SICI)1099-1271(199805/06)13:3<117::AID-BIO473>3.0.CO;2-F PG 7 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA ZZ900 UT WOS:000074780800001 PM 9693978 ER PT J AU Durkin, DP Cole, KA Copper, CL AF Durkin, DP Cole, KA Copper, CL TI Capillary electrophoretic determination of carboxyhemoglobin concentrations in postmortem blood samples SO JOURNAL OF CAPILLARY ELECTROPHORESIS LA English DT Article DE capillary electrophoresis; blood; hemoglobin; heme; carbon monoxide AB The use of capillary electrophoresis (CE) as an alternative to existing methods of quantitation of carbon monoxide (CO) in hemoglobin from postmortem blood samples is presented. The isolation of heme (the portion of the hemoglobin molecule in which CO binding takes place) from hemoglobin is described. Reduced (containing no gas molecules) heme and CO-heme isolated from hemoglobin standards were successfully separated using CE. Heme and CO-heme were also isolated from blood samples of accident victims and analyzed using CE. A quantifiable difference in the CO-heme signals from blood samples containing fatal and nonfatal levels of CO was observed.. C1 USN Acad, Annapolis, MD 21402 USA. USAF, Inst Pathol, Rockville, MD USA. NR 7 TC 1 Z9 1 U1 0 U2 0 PU I S C TECHNICAL PUBLICATIONS, INC PI SHELTON PA 30 CONTROLS DR, BOX 828, SHELTON, CT 06484-0828 USA SN 1079-5383 J9 J CAPILLARY ELECTROP JI J. Capillary Electrophor. PD MAY-AUG PY 1998 VL 5 IS 3-4 BP 129 EP 132 PG 4 WC Biochemistry & Molecular Biology; Electrochemistry SC Biochemistry & Molecular Biology; Electrochemistry GA 276TG UT WOS:000084893000006 PM 10797877 ER PT J AU Tripp, HF Bolton, JWR AF Tripp, HF Bolton, JWR TI Phrenic nerve injury following cardiac surgery: A review SO JOURNAL OF CARDIAC SURGERY LA English DT Review ID OPEN-HEART-SURGERY; INTERNAL-MAMMARY-ARTERY; DIAPHRAGMATIC DYSFUNCTION; OPERATIONS; PARALYSIS; PALSY AB Phrenic nerve injury following cardiac surgery is variable in its incidence depending on the diligence with which it is sought. Definitive studies have shown this complication to be related to cold-induced injury during myocardial protection strategies and possibly to mechanical injury during internal mammary artery harvesting. The consequences are also variable and depend to a large extent on the underlying condition of the patient, particularly with regard to pulmonary function. The response of the patient may range from an asymptomatic radiographic abnormality to severe pulmonary dysfunction requiring prolonged mechanical ventilation and other associated morbidities and even mortality. Two cases are presented to demonstrate the variability in clinical responses to diaphragmatic dysfunction secondary to phrenic nerve injury from cardiac surgery. In addition, treatment strategies are reviewed including early tracheostomy and diaphragmatic plication, which appear to be the most effective options for patients who are compromised by phrenic injuries. C1 Wilford Hall USAF Med Ctr, MKSC, Dept Cardiothorac Surg, Lackland AFB, TX 78236 USA. RP Tripp, HF (reprint author), Wilford Hall USAF Med Ctr, MKSC, Dept Cardiothorac Surg, MC,59 MDW-MKSC,2200 Bergquist Dr,Ste 1, Lackland AFB, TX 78236 USA. NR 29 TC 42 Z9 42 U1 0 U2 0 PU FUTURA PUBL CO PI ARMONK PA 135 BEDFORD RD, PO BOX 418, ARMONK, NY 10504-0418 USA SN 0886-0440 J9 J CARDIAC SURG JI J. Card. Surg. PD MAY-JUN PY 1998 VL 13 IS 3 BP 218 EP 223 PG 6 WC Cardiac & Cardiovascular Systems; Surgery SC Cardiovascular System & Cardiology; Surgery GA 222WQ UT WOS:000081808700011 PM 10193993 ER PT J AU Muthuvenkatraman, S Gorantla, S Venkat, R Dorsey, DL AF Muthuvenkatraman, S Gorantla, S Venkat, R Dorsey, DL TI Antisite arsenic incorporation in the low temperature MBE of gallium arsenide: Physics and modeling SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Article DE antisite arsenic; GaAs; low temperature molecular beam epitaxy (LT MBE) ID MOLECULAR-BEAM EPITAXY; GAAS; GROWTH; SEMICONDUCTORS AB A stochastic model for simulating the surface growth processes in the low temperature molecular beam epitaxy of gallium arsenide is developed to investigate the incorporation of antisite As and its dependence on the growth conditions including the dynamics of the physisorbed As on the surface. Three different kinetic models with a combination of surface kinetic processes such as incorporation of antisite As, evaporation of antisite As and incorporation of regular As. The kinetic model with all three surface processes was accepted as the best model due to its physical soundness and reasonableness of its model parameters. The arsenic flux, temperature, and growth rate dependences of antisite arsenic (AS(Ga)) obtained from our simulation are in excellent agreement with the experimental results. The activation energy of 1.16 eV and a frequency factor of 4 x 10(12)/s for the evaporation of antisite arsenic obtained from our model are in good agreement with experimental and theoretical estimates. At a constant substrate temperature and growth rate, the antisite arsenic concentration increases with arsenic flux for low fluxes and saturates beyond a critical flux. The critical arsenic flux increases with temperature and the saturation value of the As-Ga concentration decreases with temperature. As the arsenic flux increases, the coverage of the physisorbed layer increases and at a critical flux dictated by the fixed temperature and growth rate, the coverage saturates at its maximum value of unity (a complete monolayer) and hence the concentration of AsG(a) saturates. Lower As-Ga concentration results at higher temperature due to more evaporation of As-Ga. Additionally, an analytical model is developed to predict the As-Ga concentration for various growth conditions. C1 Univ Nevada, Dept Elect & Comp Engn, Las Vegas, NV 89154 USA. USAF, Res Lab, Mat & Mfg Directorate, Wright Patterson AFB, OH 45433 USA. RP Muthuvenkatraman, S (reprint author), Univ Nevada, Dept Elect & Comp Engn, Las Vegas, NV 89154 USA. NR 24 TC 5 Z9 5 U1 0 U2 4 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 USA SN 0361-5235 J9 J ELECTRON MATER JI J. Electron. Mater. PD MAY PY 1998 VL 27 IS 5 BP 472 EP 478 DI 10.1007/s11664-998-0179-z PG 7 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA ZN091 UT WOS:000073608700015 ER PT J AU Stutz, CE Mack, M Bremser, MD Nam, OH Davis, RF Look, DC AF Stutz, CE Mack, M Bremser, MD Nam, OH Davis, RF Look, DC TI Photoelectrochemical capacitance-voltage measurements in GaN SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Letter DE carrier concentration depth profile; GaN; photoelectrochemical etching ID WET AB Photoelectrochemical etching of GaN, using a KOH solution and a 325 nm wavelength UV laser, has been used to obtain carrier concentration depth profiles. The photoelectrochemical capacitance-voltage measurements are supported with conventional depletion mode capacitance-voltage, secondary ion mass spectroscopy, and Hall measurements. The data show that steps in carrier concentration profiles can be accurately reproduced. C1 USAF, Wright Lab, AAD, Wright Patterson AFB, OH 45433 USA. Univ Calif Santa Barbara, Santa Barbara, CA 93106 USA. N Carolina State Univ, Raleigh, NC 27695 USA. Wright State Univ, Univ Res Ctr, Dayton, OH 45435 USA. RP Stutz, CE (reprint author), USAF, Wright Lab, AAD, 2241 Avion Circle, Wright Patterson AFB, OH 45433 USA. RI Davis, Robert/A-9376-2011 OI Davis, Robert/0000-0002-4437-0885 NR 7 TC 9 Z9 9 U1 0 U2 1 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 USA SN 0361-5235 J9 J ELECTRON MATER JI J. Electron. Mater. PD MAY PY 1998 VL 27 IS 5 BP L26 EP L28 DI 10.1007/s11664-998-0182-4 PG 3 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA ZN091 UT WOS:000073608700018 ER PT J AU Albert, JM Ginet, GP Gussenhoven, MS AF Albert, JM Ginet, GP Gussenhoven, MS TI CRRES observations of radiation belt protons - 1. Data overview and steady state radial diffusion SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID MODEL; INNER AB The Proton Telescope (PROTEL) instrument on the CRRES satellite made measurements of omnidirectional differential proton flux in the energy range 1-100 MeV, with full pitch angle resolution. An overview of the equatorially mirroring particle data is presented for the entire CRRES mission. We then consider the equatorially mirroring particle distribution in terms of steady state radial diffusion theory. The outer zone, 1.7 less than or equal to L less than or equal to 3, is shown to have deviated drastically from steady state profiles both before and after the magnetic storm of March 24, 1991, which rearranged the outer zone but left the inner zone, L less than or equal to 1.7, largely unaffected. Time-averaged measurements are compared to theoretical steady state diffusion profiles of the inner zone, which are calculated using several different, previously introduced models of the plasmaspheric electron density and cosmic ray albedo neutron decay (CRAND). For each combination of models, a four-parameter (electrostatic plus magnetic) radial diffusion coefficient is sought which minimizes the difference between the measurements and calculated flux values. While the best fit values found are physically implausible, nearly equally good results are obtained for values only moderately adjusted from standard, consensus values. C1 Boston Coll, Inst Sci Res, Boston, MA 02115 USA. USAF, Res Lab, VSBS, Hanscom AFB, MA 01731 USA. RP Albert, JM (reprint author), Boston Coll, Inst Sci Res, Boston, MA 02115 USA. OI Albert, Jay/0000-0001-9494-7630 NR 39 TC 28 Z9 29 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD MAY 1 PY 1998 VL 103 IS A5 BP 9261 EP 9273 DI 10.1029/97JA02869 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA ZL412 UT WOS:000073430300016 ER PT J AU Whalen, JA AF Whalen, JA TI Appleton anomaly increase following sunset; Its observed relation to equatorial F layer E x B drift velocity SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID VERTICAL PLASMA DRIFTS; ELECTRIC-FIELD; SPREAD-F; REGION; DYNAMO AB The upward E x B drift velocity of the postsunset F layer at the dip equator, in response to the prereversal electric field, and the resulting enhancement of the fountain effect plasma at the Appleton anomaly are observed nearly simultaneously near the same geomagnetic meridian. Measurements, the first under such controlled conditions, are by a chain of ionospheric sounders recording ionograms at intervals of 5-15 min on two consecutive days during equinox at solar maximum, both having quiet magnetic conditions and high solar fluxes. Measured is the following sequence of cause and effect: the equatorial F layer electron density that persists through sunset; the solar E layer electron density conjugate to this F layer that decays rapidly through sunset; the bottomside equatorial F layer altitude, h'F, as it drifts upward in response to the F region dynamo electric field; and the anomaly F layer electron density that increases with the arrival of the resulting enhanced fountain effect plasma at 16.0 degrees and at 20.3 degrees dip latitude. At the equator the maximum drift velocity measured by dh 'F/dt is 70 m s(-1) on the first day and 50 m s(-1) on the second. The differences in drift velocity are reflected in the anomaly in latitudinal distributions of F layer maximum electron density between 0 degrees and 30 degrees dip latitude that show the anomaly crest to increase in magnitude and in latitude: rapidly on the first day, reaching a maximum of 55 x 10(5) el cm(-3) at 18 degrees dip latitude at 2100 LT, and more slowly on the second day, reaching greater than or equal to 38 x 10(5) el cm(-3) at less than or equal to 16 degrees dip latitude, also at 2100 LT. In addition to the qualitative relationship, maximum drift velocity and anomaly crest maximum electron density and its maximum rate of increase are all reduced by about the same factor on the second day relative to the first. C1 VSBP, Air Force Res Lab, Hanscom AFB, MA 01731 USA. RP Whalen, JA (reprint author), VSBP, Air Force Res Lab, 29 Randolph Rd, Hanscom AFB, MA 01731 USA. NR 22 TC 8 Z9 8 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD MAY 1 PY 1998 VL 103 IS A5 BP 9497 EP 9503 DI 10.1029/98JA00104 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA ZL412 UT WOS:000073430300039 ER PT J AU Pachter, M Chandler, PR Smith, L AF Pachter, M Chandler, PR Smith, L TI Maneuvering flight control SO JOURNAL OF GUIDANCE CONTROL AND DYNAMICS LA English DT Article; Proceedings Paper CT 1997 American Control Conference CY JUN 04-06, 1997 CL ALBUQUERQUE, NEW MEXICO SP Amer Automat Control Council, Int Federat Automat Control AB The development of control laws for maneuvering flight, specifically, a high-amplitude velocity-vector roll, is addressed. The plant model has seventh-order nonlinear dynamics with coupled pitch and lateral directional dynamics. Using time scale separation and pointwise linearization about nonequilibria trajectories, a receding horizon linear quadratic optimal control law with full state feedback is synthesized on-line. Also on-line, the pilot inputs are modified using linear programming to prevent actuator rate saturation over the optimization horizon. The nonlinear control law performance is demonstrated in a fighter aircraft simulation with a rudder failure during a loaded roll maneuver. The performance of the controller during aggressive pitch and yaw maneuvers is also demonstrated The work described in this paper is confined to model-based receding horizon optimal control law synthesis; one will rely on on-line system identification to provide the failed aerodynamic stability and control derivatives, thus achieving indirect adaptive control. C1 USAF, Inst Technol, Dept Elect & Comp Engn, Wright Patterson AFB, OH 45433 USA. USAF, Res Lab, Flight Control Div, Wright Patterson AFB, OH 45433 USA. RP Pachter, M (reprint author), USAF, Inst Technol, Dept Elect & Comp Engn, Wright Patterson AFB, OH 45433 USA. NR 10 TC 4 Z9 4 U1 0 U2 2 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0731-5090 J9 J GUID CONTROL DYNAM JI J. Guid. Control Dyn. PD MAY-JUN PY 1998 VL 21 IS 3 BP 368 EP 374 DI 10.2514/2.4264 PG 7 WC Engineering, Aerospace; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA ZN665 UT WOS:000073669400002 ER PT J AU Hall, CD AF Hall, CD TI Escape from gyrostat trap states SO JOURNAL OF GUIDANCE CONTROL AND DYNAMICS LA English DT Article; Proceedings Paper CT AAS/AIAA Astrodynamics Conference CY FEB 14-17, 1995 CL HALIFAX, CANADA SP Amer Astron Soc, Amer Inst Aeronaut & Astronaut ID DUAL-SPIN SPACECRAFT; RESONANCE CAPTURE; DYNAMICS; DESPIN AB Some results are presented on the dynamics of gyrostats containing two axisymmetric rotors where one of the rotors is viscously damped and the other is subject to a controllable torque. The purpose of this arrangement is to investigate the use of internal torques to enable a spacecraft to escape from a trap state. Suppose the spacecraft is intended to operate in a state in which the primary rotor R-1 has a specified angular momentum and the other rotor R-2, subject only to internal viscous torques, is not spinning relative to the spacecraft reference frame. Normally this state is asymptotically stable because of the damping. It is possible that a different asymptotically stable state exists satisfying these conditions on the rotor momenta, in much the same way that a single-spinner may spin in either direction about its major axis. If the spacecraft becomes trapped in the alternate state, it is necessary to help it escape. In an earlier study, a pulsing procedure was proposed. Herein we show that periodic torquing of the primary rotor may lead to escape hut generally is rather ineffective. An alternative escape procedure is presented that essentially is guaranteed to lead to escape. Unlike the local analysis that suggests the pulsing procedure, the procedure used here is based on a global analysis of the rotational dynamics. C1 USAF, Inst Technol, Grad Sch Engn, Dept Aeronaut & Astronaut, Wright Patterson AFB, OH 45433 USA. RP Hall, CD (reprint author), Virginia Polytech Inst & State Univ, Dept Aerosp & Ocean Engn, Blacksburg, VA 24061 USA. NR 25 TC 17 Z9 17 U1 1 U2 1 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0731-5090 J9 J GUID CONTROL DYNAM JI J. Guid. Control Dyn. PD MAY-JUN PY 1998 VL 21 IS 3 BP 421 EP 426 DI 10.2514/2.4275 PG 6 WC Engineering, Aerospace; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA ZN665 UT WOS:000073669400009 ER PT J AU Buffington, JM Enns, DF Teel, AR AF Buffington, JM Enns, DF Teel, AR TI Control allocation and zero dynamics SO JOURNAL OF GUIDANCE CONTROL AND DYNAMICS LA English DT Article; Proceedings Paper CT AIAA Guidance, Navigation, and Control Conference and Exhibit CY JUL 29-31, 1996 CL SAN DIEGO, CALIFORNIA SP AIAA ID CONSTRAINED CONTROL ALLOCATION; OF-ATTACK FLIGHT AB Closed-loop stability for dynamic inversion controllers depends on the stability of the zero dynamics. The zero dynamics,however, depend on a generally nonlinear control allocation function that optimally distributes redundant controls. Therefore, closed-loop stability depends on the control allocation function. A sufficient condition is provided for globally asymptotically stable zero dynamics with a class of admissible nonlinear control allocation functions. It is shown that many common control allocation functions belong to the class of functions that are covered by the aforementioned zero dynamics stability condition. Aircraft flight control examples are given to demonstrate the utility of the results. C1 USAF, Res Lab, Flight Control Div, Wright Lab, Wright Patterson AFB, OH 45433 USA. Honeywell Technol Ctr, Minneapolis, MN 55418 USA. Univ Minnesota, Dept Elect Engn, Minneapolis, MN 55455 USA. RP Buffington, JM (reprint author), USAF, Res Lab, Flight Control Div, Wright Lab, FIGC-3,2210 8th St, Wright Patterson AFB, OH 45433 USA. NR 20 TC 14 Z9 16 U1 0 U2 5 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0731-5090 J9 J GUID CONTROL DYNAM JI J. Guid. Control Dyn. PD MAY-JUN PY 1998 VL 21 IS 3 BP 458 EP 464 DI 10.2514/2.4258 PG 7 WC Engineering, Aerospace; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA ZN665 UT WOS:000073669400014 ER PT J AU Vergez, PL AF Vergez, PL TI Tactical missile guidance with passive seekers under high off-boresight launch conditions SO JOURNAL OF GUIDANCE CONTROL AND DYNAMICS LA English DT Article AB For future short range air-to-air missile concepts, it has been recently demonstrated that throttleable hybrid rocket motors, coupled with linear optimal guidance laws, provide significant performance improvements over traditional solid rocket motors utilizing similar guidance laws in high off-boresight launch conditions. A problem associated with these optimal guidance laws is that they require missile-to-target position, velocity, and acceleration. For practical missile applications, only the initial values of relative position and velocity and an initial guess of the target's acceleration would be available from the launching aircraft. To further complicate the situation, most short-range missiles use a passive seeker, providing angle only measurements, and accelerometers to measure the missile's accelerations. An extended Kalman filter (EKF) is developed to estimate the required guidance information using passive seeker measurements. The performance of a missile with a passive seeker in high off-boresight launch conditions is evaluated using the combination of an EKF and the guidance law. In particular, a comparison is made between three guidance schemes using estimated states from an EKF. The three guidance schemes are 1) an optimal guidance law coupled with a solid rocket motor, 2) an optimal guidance law coupled with a hybrid rocket motor, and 3) proportional navigation coupled with a solid rocket motor. The results show that the optimal guidance law coupled with a hybrid rocket motor provides a significant improvement in high off-boresight, air-to-air engagements over proportional navigation and the optimal guidance law coupled with a solid rocket motor. C1 USAF Acad, Dept Astron, Colorado Springs, CO 80840 USA. RP Vergez, PL (reprint author), USAF Acad, Dept Astron, 2354 Fairchild Dr,Suite 6J75, Colorado Springs, CO 80840 USA. NR 9 TC 2 Z9 3 U1 0 U2 1 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0731-5090 J9 J GUID CONTROL DYNAM JI J. Guid. Control Dyn. PD MAY-JUN PY 1998 VL 21 IS 3 BP 465 EP 470 DI 10.2514/2.4259 PG 6 WC Engineering, Aerospace; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA ZN665 UT WOS:000073669400015 ER PT J AU Yale, GE Agrawal, BN AF Yale, GE Agrawal, BN TI Lyapunov controller for cooperative space manipulators SO JOURNAL OF GUIDANCE CONTROL AND DYNAMICS LA English DT Article ID SATELLITE AB The cooperative control of multiple manipulators attached to the same base as they reposition a common payload is discussed. The theory is easily applied to inertially based problems, as well as space-based free-floating platforms. The system equations of motion are developed, as well as a Lyapunov-based controller that ensures stability. The closed chain aspect of the problem reduces the system's degrees of freedom resulting in more actuators than degrees of freedom. This actuator redundancy is used to minimize a weighted norm of the actuator torques. A polynomial reference trajectory describes the path the payload wilt follow. The disturbance torque transmitted to the spacecraft centerbody by the motion of the manipulators is reduced by altering the order of the reference trajectory polynomial and its coefficients. Results from a two-dimensional, dual-arm configuration are included. Compared to the Lyapunov point controller alone, the addition of a fifth-order polynomial reference trajectory leads to superior performance in terms of actuator torque magnitudes, spacecraft centerbody attitude control, and payload repositioning accuracy and time. An eighth-order polynomial reference trajectory results in only small improvement over the fifth-order case. C1 USAF Acad, Dept Astron, Colorado Springs, CO 80840 USA. USN, Postgrad Sch, Dept Aeronaut & Astronaut, Monterey, CA 93940 USA. RP Yale, GE (reprint author), USAF Acad, Dept Astron, Colorado Springs, CO 80840 USA. NR 12 TC 11 Z9 15 U1 0 U2 2 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0731-5090 J9 J GUID CONTROL DYNAM JI J. Guid. Control Dyn. PD MAY-JUN PY 1998 VL 21 IS 3 BP 477 EP 484 DI 10.2514/2.4261 PG 8 WC Engineering, Aerospace; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA ZN665 UT WOS:000073669400017 ER PT J AU Schumacher, C Khargonekar, PP AF Schumacher, C Khargonekar, PP TI Stability analysis of a missile control system with a dynamic inversion controller SO JOURNAL OF GUIDANCE CONTROL AND DYNAMICS LA English DT Article ID FLIGHT AB The closed-loop stability is examined of a bank;to-turn, air-to-air missile with a dynamic inversion controller using a two-timescale separation. A state-space formulation for the alpha, beta, and phi dynamics of the missile, assuming the inner-loop dynamic inversion is performed exactly, is presented. It is then shown that, under Certain assumptions, the exponential stability of the alpha, beta, and phi dynamics about the commanded values can be guaranteed if the inner-loop design frequency is large enough. An example calculation of the required inner-loop frequency to guarantee stability is done for a particular bank-to-turn missile. Finally, nonlinear six-degree of-freedom simulation results of a maneuver performed with the dynamic inversion controller are presented. C1 USAF, Res Lab, VACC, Wright Patterson AFB, OH 45433 USA. Univ Michigan, Dept Elect Engn & Comp Sci, Ann Arbor, MI 48109 USA. RP Schumacher, C (reprint author), USAF, Res Lab, VACC, Bldg 146,2210 8th St,Suite 21, Wright Patterson AFB, OH 45433 USA. EM coreys@falcon.flight.wpafb.af.mil; pramod@eecs.umich.edu OI Khargonekar, Pramod/0000-0001-6634-6950 NR 13 TC 39 Z9 50 U1 0 U2 3 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0731-5090 J9 J GUID CONTROL DYNAM JI J. Guid. Control Dyn. PD MAY-JUN PY 1998 VL 21 IS 3 BP 508 EP 515 DI 10.2514/2.4266 PG 8 WC Engineering, Aerospace; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA ZN665 UT WOS:000073669400021 ER PT J AU Thomas, SK Klasing, KS Yerkes, KL AF Thomas, SK Klasing, KS Yerkes, KL TI The effects of transverse acceleration-induced body forces on the capillary limit of helically grooved heat pipes SO JOURNAL OF HEAT TRANSFER-TRANSACTIONS OF THE ASME LA English DT Article; Proceedings Paper CT International Mechanical Engineering Congress and Exposition, at the Winter Annual Meeting of the American-Society-of-Mechanical-Engineers CY NOV 16-21, 1997 CL DALLAS, TEXAS SP Amer Soc Mech Engineers DE experimental; heat transfer; heat pipes; liquid; rotating ID BEHAVIOR AB A helically grooved copper heat pipe with ethanol as the working fluid has been fabricated and tested on a centrifuge table. The heat pipe was bent to match the radius of curvature of the table so that uniform transverse (perpendicular to the axis of the heat pipe) body force fields could be applied along the entire length of the pipe. By varying the heat input (Q(in) = 25 to 250 W) and centrifuge table velocity (radial acceleration \(a) over right arrow(r)\ = 0 to 10g), information on dryout phenomena, circumferential temperature uniformity, heat lost to the environment, thermal resistance, and the capillary limit to heat transport was obtained. Due to the geometry of the helical grooves, the capillary limit increased by a factor of five when the radial acceleration increased from \(a) over right arrow(r)\ = 0 to 6.0g. This important result was verified by a mathematical model of the heat pipe system, wherein the capillary limit to heat transport of each groove was calculated in terms of centrifuge table angular velocity, the geometry of the heat pipe and the grooves (including helix pitch), and temperature-dependent working fluid properties. In addition, a qualitative study was executed with a copper-ethanol heat pipe with straight axial grooves, This experimental study showed that the performance of the hear pipe with straight grooves was not improved when the radial acceleration was increased from \(a) over right arrow(r)\ = 0 to 10.0g. C1 Wright State Univ, Dept Mech & Mat Engn, Dayton, OH 45435 USA. USAF, Res Lab, PRPG, Wright Patterson AFB, OH 45433 USA. RP Thomas, SK (reprint author), Wright State Univ, Dept Mech & Mat Engn, Dayton, OH 45435 USA. NR 15 TC 8 Z9 8 U1 1 U2 4 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0022-1481 J9 J HEAT TRANS-T ASME JI J. Heat Transf.-Trans. ASME PD MAY PY 1998 VL 120 IS 2 BP 441 EP 451 DI 10.1115/1.2824269 PG 11 WC Thermodynamics; Engineering, Mechanical SC Thermodynamics; Engineering GA ZR720 UT WOS:000074007000021 ER PT J AU Lair, AV Oxley, ME AF Lair, AV Oxley, ME TI A necessary and sufficient condition for global existence for a degenerate parabolic boundary value problem SO JOURNAL OF MATHEMATICAL ANALYSIS AND APPLICATIONS LA English DT Article DE degenerate parabolic equation; global solution; finite time blowup; Neumann boundary condition; generalized solution ID LINEAR HEAT-EQUATIONS; BLOW-UP AB Consider the degenerate parabolic boundary value problem u(t) = Delta phi(u) + f(u) on Omega X (0, infinity) in which Omega is a bounded domain in R-N and the C([0, infinity)) functions f and phi are nonnegative and nondecreasing with phi(s)f(s) > 0 if s > 0 and phi(0) = 0. Assume homogeneous Neumann boundary conditions and an initial condition that is nonnegative, nontrivial, and continuous on <(Omega)over bar>. Because the function phi is not sufficiently nice to allow this problem to have a classical solution, we consider generalized solutions in a manner similar to that of Benilan, Crandall, and Sacks [Appl. Math. Optim. 17 (1988), 203-224]. We show that this initial boundary value problem has such a nonnegative generalized solution if and only if integral(0)(infinity) ds/(1 + f(s)) = infinity. (C) 1998 Academic Press. C1 USAF, Dept Math & Stat, Inst Technol, Wright Patterson AFB, OH 45433 USA. RP Lair, AV (reprint author), USAF, Dept Math & Stat, Inst Technol, 2950 P St, Wright Patterson AFB, OH 45433 USA. NR 17 TC 15 Z9 17 U1 0 U2 0 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0022-247X J9 J MATH ANAL APPL JI J. Math. Anal. Appl. PD MAY 1 PY 1998 VL 221 IS 1 BP 338 EP 348 DI 10.1006/jmaa.1997.5900 PG 11 WC Mathematics, Applied; Mathematics SC Mathematics GA ZJ837 UT WOS:000073258700018 ER PT J AU Pinkerton, KC Wimsatt, JA AF Pinkerton, KC Wimsatt, JA TI A simple, atraumatic technique for the dissection of nasal mucosa during Le fort I osteotomy SO JOURNAL OF ORAL AND MAXILLOFACIAL SURGERY LA English DT Article C1 USAF, Med Ctr, Dept Oral & Maxillofacial Surg, Scott AFB, IL USA. RP Pinkerton, KC (reprint author), 1305 Wonderworld Dr,Suite 303, San Marcos, TX 78666 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU W B SAUNDERS CO PI PHILADELPHIA PA INDEPENDENCE SQUARE WEST CURTIS CENTER, STE 300, PHILADELPHIA, PA 19106-3399 USA SN 0278-2391 J9 J ORAL MAXIL SURG JI J. Oral Maxillofac. Surg. PD MAY PY 1998 VL 56 IS 5 BP 687 EP 688 DI 10.1016/S0278-2391(98)90476-1 PG 2 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA ZL889 UT WOS:000073483700032 PM 9590355 ER PT J AU Slater, LJ AF Slater, LJ TI Distinguishing calcium pyrophosphate dihydrate deposition disease from synovial chondrosarcoma SO JOURNAL OF ORAL AND MAXILLOFACIAL SURGERY LA English DT Letter C1 USAF, Washington, DC 20330 USA. RP Slater, LJ (reprint author), USAF, Washington, DC 20330 USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU W B SAUNDERS CO PI PHILADELPHIA PA INDEPENDENCE SQUARE WEST CURTIS CENTER, STE 300, PHILADELPHIA, PA 19106-3399 USA SN 0278-2391 J9 J ORAL MAXIL SURG JI J. Oral Maxillofac. Surg. PD MAY PY 1998 VL 56 IS 5 BP 693 EP 693 DI 10.1016/S0278-2391(98)90491-8 PG 1 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA ZL889 UT WOS:000073483700033 PM 9590356 ER PT J AU Katta, VR Roquemore, WM AF Katta, VR Roquemore, WM TI Study on trapped-vortex combustor - Effect of injection on flow dynamics SO JOURNAL OF PROPULSION AND POWER LA English DT Article; Proceedings Paper CT AIAA/ASME/SAE/ASEE 33rd Joint Propulsion Conference CY JUL 06-09, 1997 CL SEATTLE, WASHINGTON SP Amer Inst Aeronaut & Astronaut, ASME, SAE, ASEE ID FLAME AB Low-velocity flows in the cavities of a combustor can aid in establishing stable names. However, unsteady flows in and around cavities may destabilize these names. By proper cavity design it is possible to lock (trap) the vortices spatially and, thereby, stabilize the names. The spatially locked vortices restrict the entrainment of main air into the cavity. For obtaining good performance characteristics with a trapped-vortex combustor, a sufficient amount of fuel and air must be injected directly into the cavity. This mass injection can alter the dynamic characteristics of the flow inside and around the cavity. The present study employed a numerical simulation to investigate the vortex dynamics of a cavity into which fluid mass is directly injected through jets. A third-order-accurate time-dependent, computational fluid dynamics with chemistry code was used for simulating the-dynamic flows associated with an axisymmetric, centerbody trapped-vortex combustor under nonreacting and reacting conditions. It was found that mass injection increases the optimum size (width-to-diameter ratio) of the cavity, Injection of small amounts of fluid into a nonoptimum cavity increases the unsteadiness of the flow. Fluid injected into the optimum-size cavity is transported along the outer core of the vortex, providing more efficient mixing and a longer residence time for the fuel/air mixture. It was also found that use of thinner afterbodies results in the cavity flow being more dynamic. Calculations made with a global-chemistry model revealed that at higher annulus air velocities, combustion is limited to the cavity region. As in the case of cold flows, the injection jets in reacting flows are pushed outward from the center when the cavity size is small. C1 Innovat Sci Solut Inc, Dayton, OH 45440 USA. USAF, Res Lab, Wright Patterson AFB, OH 45433 USA. RP Katta, VR (reprint author), Innovat Sci Solut Inc, Dayton, OH 45440 USA. NR 13 TC 32 Z9 34 U1 1 U2 4 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0748-4658 J9 J PROPUL POWER JI J. Propul. Power PD MAY-JUN PY 1998 VL 14 IS 3 BP 273 EP 281 DI 10.2514/2.5286 PG 9 WC Engineering, Aerospace SC Engineering GA ZN922 UT WOS:000073697000001 ER PT J AU Ahmed, LN Crofton, MW AF Ahmed, LN Crofton, MW TI Surface modification measurements in the T5 ion thruster plume SO JOURNAL OF PROPULSION AND POWER LA English DT Article AB The measurement and analysis of thruster-induced surface modifications of a variety of materials in the T5 (UK-10) xenon ion engine environment has been performed. Surface modification because of impinging contaminants in the thruster ground-test environment was studied for about 50 collimated spacecraft material samples at fixed sites, including solar cells, paints, and optical solar reflectors. Emittance and solar absorptance properties were determined pretest and posttest. Elemental composition was determined for the deposition surface layers accumulated during the 65-h exposure of the various samples, to obtain mass deposition rates for individual elements. While a number of samples acted as simple sputter monitors, behavior of the paints was complex, showing strong dependence of posttest surface deposition layer on paint chemistry. Angular distributions of the total mass deposition rate were obtained with a rotatable, collimated quartz crystal microbalance (QCM). Results from most samples and the QCM show increasing deposition of molybdenum with increasing observation angle. Deposition increased rapidly from 20 to 35 deg off the grid plane, and observed deposition rate peaked at approximately 45 deg. The variation of deposition rate with accelerator and decelerator grid voltages, propellant mass utilization, and facility background pressure was also investigated. The results are relevant to the impact of thruster operation on spacecraft surfaces and the evaluation of thruster grid lifetime as a function of operating point. C1 Aerospace Corp, El Segundo, CA 90245 USA. RP Ahmed, LN (reprint author), USAF, Syst Program Off F16, ASC YPX, 1981 Monahan Way, Wright Patterson AFB, OH 45433 USA. NR 35 TC 1 Z9 2 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0748-4658 J9 J PROPUL POWER JI J. Propul. Power PD MAY-JUN PY 1998 VL 14 IS 3 BP 336 EP 347 DI 10.2514/2.5302 PG 12 WC Engineering, Aerospace SC Engineering GA ZN922 UT WOS:000073697000009 ER PT J AU Olsem, MR AF Olsem, MR TI An incremental approach to software systems re-engineering SO JOURNAL OF SOFTWARE MAINTENANCE-RESEARCH AND PRACTICE LA English DT Article DE incremental re-engineering; evolutionary re-engineering; partial re-engineering; trickle-down reengineering; revolutionary re-engineering; lump-sum re-engineering ID LEGACY SYSTEMS; REVERSE AB Software re-engineering can dramatically improve an organization's ability to maintain and upgrade its legacy production systems, But the risks that accompany traditional re-engineering tend to offset the potential benefits. Incremental software re-engineering is the practice of re-engineering a system's software components on a phased basis, and then re-incorporating those components into production also on a phased basis. Incremental software re-engineering allows for safer re-engineering, increased flexibility and more immediate return on investment. But commercial automation to support incremental software re-engineering is currently weak. In addition, project managers need a methodology to plan and implement software re-engineering projects based on the incremental approach. This paper covers the advantages of incremental software re-engineering and what is available concerning support technology. The paper describes a process methodology for planning and implementing incremental software re-engineering projects, Finally, gaps in the support technology are identified with suggestions for future tools from vendors. (C) 1998 John Wiley & Sons, Ltd. C1 USAF, Software Technol Support Ctr, Ogden, UT 84056 USA. RP Olsem, MR (reprint author), 9401 Lakewood Circle, Norwalk, IA 50211 USA. NR 19 TC 6 Z9 6 U1 0 U2 0 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 1040-550X J9 J SOFTW MAINT-RES PR JI J. Softw. Maint.-Res. Pract. PD MAY-JUN PY 1998 VL 10 IS 3 BP 181 EP 202 DI 10.1002/(SICI)1096-908X(199805/06)10:3<181::AID-SMR171>3.0.CO;2-7 PG 22 WC Computer Science, Software Engineering SC Computer Science GA ZY734 UT WOS:000074654000002 ER PT J AU Moe, K Moe, MM Wallace, SD AF Moe, K Moe, MM Wallace, SD TI Improved satellite drag coefficient calculations from orbital measurements of energy accommodation SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article AB Significant discoveries about gas-surface interactions that have been made in 90 years of laboratory experiments and 30 years of orbital measurements are reviewed. This information is used to improve the calculation of drag coefficients for satellites in low Earth orbit for several different satellite shapes and orientations by inserting the appropriate parameters in theoretical models of the drag coefficient. The drag coefficients so calculated provide increased consistency in orbital measurements of astmospheric density by satellites of different shapes near 200 km, where adsorbed atomic oxygen dominates the interaction and causes the energy accommodation coefficient to approach unity. It is essential to improve the numerical value of the drag coefficient so that the density of the neutral thermosphere can Ire inferred from satellite drag to better than the present 15% uncertainty. The key to this improvement is the calculation of drag coefficients from parameters measured in space, rather than from those measured in the laboratory under conditions very different from the space environment. C1 USAF, Space & Missile Syst Ctr, Dev Planning Off, El Segundo, CA 90245 USA. Univ Calif Irvine, Dept Phys, Irvine, CA 92612 USA. Univ Calif San Diego, Dept Comp Sci & Engn, La Jolla, CA 92093 USA. RP Moe, K (reprint author), USAF, Space & Missile Syst Ctr, Dev Planning Off, El Segundo, CA 90245 USA. NR 44 TC 37 Z9 39 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD MAY-JUN PY 1998 VL 35 IS 3 BP 266 EP 272 DI 10.2514/2.3350 PG 7 WC Engineering, Aerospace SC Engineering GA ZT729 UT WOS:000074119200004 ER PT J AU Patel, SB Callahan, TF Callahan, MG Jones, JT Graber, GP Foster, KS Glifort, K Wodicka, GR AF Patel, SB Callahan, TF Callahan, MG Jones, JT Graber, GP Foster, KS Glifort, K Wodicka, GR TI An adaptive noise reduction stethoscope for auscultation in high noise environments SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article AB Auscultation of lung sounds in patient transport vehicles such as an ambulance or aircraft is unachievable because of high ambient noise levels. Aircraft noise levels of 90-100 dB SPL are common, while lung sounds have been measured in the 22-30 dB SPL range in free space and 65-70 dB SPL within a stethoscope coupler. Also, the bandwidth of lung sounds and vehicle noise typically has significant overlap, limiting the utility of traditional band-pass filtering. In this study, a passively shielded stethoscope coupler that contains one microphone to measure the (noise-corrupted) lung sounds and another to measure the ambient noise was constructed. Lung sound measurements were made on a healthy subject in a simulated USAF C-130 aircraft environment within an acoustic chamber at noise levels ranging from 80 to 100 dB SPL. Adaptive filtering schemes using a least-mean-squares (LMS) and a normalized least-mean-squares (NLMS) approach were employed to extract the lung sounds from the noise-corrupted signal. Approximately 15 dB of noise reduction over the 100-600 Hz frequency range was achieved with the LMS algorithm, with the more complex NLMS algorithm providing faster convergence and up to 5 dB of additional noise reduction. These findings indicate that a combination of active and passive noise reduction can be used to measure lung sounds in high noise environments. (C) 1998 Acoustical Society of America. C1 Purdue Univ, Sch Elect & Comp Engn, W Lafayette, IN 47907 USA. Univ Res Engineers & Associates Inc, Acton, MA 01720 USA. Purdue Univ, Hillenbrand Biomed Engn Ctr, W Lafayette, IN 47907 USA. USAF, Armstrong Lab, San Antonio, TX 78201 USA. RP Patel, SB (reprint author), Purdue Univ, Sch Elect & Comp Engn, W Lafayette, IN 47907 USA. NR 13 TC 15 Z9 15 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD MAY PY 1998 VL 103 IS 5 BP 2483 EP 2491 DI 10.1121/1.422769 PN 1 PG 9 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA ZM942 UT WOS:000073591800027 PM 9604343 ER PT J AU Ricci, RM Evans, JS Meffert, JJ Kaufman, L Sadkowski, LC AF Ricci, RM Evans, JS Meffert, JJ Kaufman, L Sadkowski, LC TI Primary cutaneous Aspergillus ustus infection: Second reported case SO JOURNAL OF THE AMERICAN ACADEMY OF DERMATOLOGY LA English DT Article AB We describe the second case of primary cutaneous Aspergillus ustus infection in an immunocompromised patient. Cutaneous aspergillosis was confirmed both by culture and positive fluorescent antibody staining. Few species of Aspergillus are pathogenic in human beings, and fewer still cause primary cutaneous disease. The only other reported case of aspergillosis from Aspergillus ustus occurred in an immunosuppressed patient who was temporally and geographically separated from ours. C1 Wilford Hall USAF Med Ctr, Lackland AFB, TX 78236 USA. Ctr Dis Control & Prevent, Div Bacterial & Mycot Dis, San Antonio, TX USA. Vet Adm Mycol Reference Lab, Atlanta, GA USA. RP Ricci, RM (reprint author), Wilford Hall USAF Med Ctr, Lackland AFB, TX 78236 USA. NR 7 TC 19 Z9 21 U1 0 U2 0 PU MOSBY-YEAR BOOK INC PI ST LOUIS PA 11830 WESTLINE INDUSTRIAL DR, ST LOUIS, MO 63146-3318 USA SN 0190-9622 J9 J AM ACAD DERMATOL JI J. Am. Acad. Dermatol. PD MAY PY 1998 VL 38 IS 5 SU S BP 797 EP 798 DI 10.1016/S0190-9622(98)70460-8 PN 2 PG 2 WC Dermatology SC Dermatology GA ZM640 UT WOS:000073560400001 PM 9591788 ER PT J AU Ham, BS Shahriar, MS Hemmer, PR AF Ham, BS Shahriar, MS Hemmer, PR TI Radio-frequency-induced optical gain in Pr3+: Y2SiO5 SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID ELECTROMAGNETICALLY INDUCED TRANSPARENCY; POPULATION-INVERSION; INTERFERENCE; LASERS AB We report an observation of radio-frequency (RF)-induced transparency in an optically dense medium of Pr3+-doped Y2SiO5. We observed that the optical probe field had a gain when the RF pulse area was 2 pi. We also calculated the RF Rabi frequency in the medium by measuring the period of RF-induced transparency. (C) 1998 Optical Society of America [S0740-3224(98)00705-X]. C1 MIT, Res Lab Elect, Cambridge, MA 02139 USA. USAF, Res Lab, Hanscom AFB, MA 01731 USA. RP MIT, Res Lab Elect, 77 Massachusetts Ave, Cambridge, MA 02139 USA. RI Shahriar, Selim/B-7270-2009 NR 21 TC 10 Z9 10 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0740-3224 EI 1520-8540 J9 J OPT SOC AM B JI J. Opt. Soc. Am. B-Opt. Phys. PD MAY PY 1998 VL 15 IS 5 BP 1541 EP 1544 DI 10.1364/JOSAB.15.001541 PG 4 WC Optics SC Optics GA ZM955 UT WOS:000073593200013 ER PT J AU Huang, DH Cardimona, DA AF Huang, DH Cardimona, DA TI Intersubband laser coupled three-level asymmetric quantum wells: new dynamics of quantum interference SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID ELECTROMAGNETICALLY INDUCED TRANSPARENCY; ATOMIC-STATE COHERENCE; INTERBAND-TRANSITIONS; INVERSION; SYSTEM; AMPLIFICATION; RESONANCE; EMISSION; FIELD; GAIN AB The improved density-functional theory is employed to obtain the eigenstates of electrons in an asymmetric quantum well. On the basis of calculated eigenstates, the semiconductor Bloch equations are used to calculate the transient density matrix when a pulsed intersubband laser coupling is applied to the system. The new dynamics of the individual absorption peaks is analyzed for the first time by use of a self-consistent-field theory. Based on this, the time-averaged optical spectrum is calculated to show the coherent-transition-induced quantum interference in the system. The new phenomena of probe-field amplification is observed, and the threshold laser intensity for observing it is given. (C) 1998 Optical Society of America [S0740-3224(98)00105-2]. C1 USAF, Phillips Lab, PL VTMR, Kirtland AFB, NM 87117 USA. RP USAF, Phillips Lab, PL VTMR, 3550 Aberdeen Ave SE, Kirtland AFB, NM 87117 USA. NR 23 TC 11 Z9 12 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0740-3224 EI 1520-8540 J9 J OPT SOC AM B JI J. Opt. Soc. Am. B-Opt. Phys. PD MAY PY 1998 VL 15 IS 5 BP 1578 EP 1584 DI 10.1364/JOSAB.15.001578 PG 7 WC Optics SC Optics GA ZM955 UT WOS:000073593200019 ER PT J AU Zabinski, JS Voevodin, AA AF Zabinski, JS Voevodin, AA TI Recent developments in the design, deposition, and processing of hard coatings SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A LA English DT Article; Proceedings Paper CT 44th National Symposium of the American-Vacuum-Society CY OCT 20-24, 1997 CL SAN JOSE, CA SP Amer Vacuum Soc ID PULSED-LASER DEPOSITION; DIAMOND-LIKE CARBON; TIC THIN-FILMS; TRIBOLOGICAL PROPERTIES; WEAR; GROWTH; MODEL AB Coatings that offer protection from wear, low friction coefficients, and corrosion resistance are required for many applications ranging from tool inserts to bearings. The precise demands placed on these coatings varies by application, but to meet new requirements a useful approach is to use established coatings in new applications or create new materials by adjusting chemistry and microstructure. To achieve significant advancements in coating properties, we must go beyond single-layer/single-phase materials. Functionally gradient, multilayer, and composite coatings permit blending of properties traditionally considered mutually exclusive; for example, hardness and toughness. To facilitate growth of these types of coatings, improved deposition techniques must be developed. Discussion in this article focuses on the development of coating materials and deposition processes at the Air Force Materials Laboratory/Materials Directorate. Materials include nitrides/ carbides and diamond-like carbon in functionally gradient, multilayer, and nanocomposite architectures. The magnetron assisted pulsed laser deposition process which permits the growth of infinitely variable gradients as well as sharp interfaces will be highlighted. C1 USAF, Res Lab, MLBT, Mat Directorate, Wright Patterson AFB, OH 45433 USA. RP Zabinski, JS (reprint author), USAF, Res Lab, MLBT, Mat Directorate, Wright Patterson AFB, OH 45433 USA. EM zabinsj@ml.wpafb.af.mil RI Voevodin, Andrey/I-6684-2013 NR 56 TC 33 Z9 34 U1 1 U2 2 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 MAY-JUN PY 1998 VL 16 IS 3 BP 1890 EP 1900 DI 10.1116/1.581124 PN 2 PG 11 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA ZT992 UT WOS:000074150500091 ER PT J AU Lin, CH Murry, SJ Yang, RQ Yang, BH Pei, SS Yan, C Gianardi, DM McDaniel, DL Falcon, M AF Lin, CH Murry, SJ Yang, RQ Yang, BH Pei, SS Yan, C Gianardi, DM McDaniel, DL Falcon, M TI Room-temperature midinfrared type-II quantum-well lasers with high power efficiency SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article; Proceedings Paper CT 16th North American Conference on Molecular Beam Epitaxy CY OCT 05-08, 1997 CL UNIV MICHIGAN, ANN ARBOR, MICHIGAN HO UNIV MICHIGAN ID MU-M AB We report the room-temperature operation of optically pumped InAs/InGaSb/InAs/AlSb type-II quantum-well lasers at 4.48 mu m with a pulse length of 650 ns and a repetition rate of 2 kHz. The absorbed threshold peak pump intensity was only 0.27 kW/cm(2) at 220 K and 1.1 kW/cm(2) at 300 K, with a characteristic temperature To of 61.6 K for temperatures up. to 300 K. At 49 K, the continuous wave output power was 4.2 mW/facet with an absorbed threshold pump power of 31.5 mW and an absorbed pump power of 62 mW, indicating a differential external quantum efficiency of 54% for two facets. (C) 1998 American Vacuum Society. C1 Univ Houston, Ctr Space Vacuum Epitaxy, Houston, TX 77204 USA. Boeing Def & Space Grp, Rocketdyne Tech Serv, Kirtland AFB, NM 87117 USA. USAF, Phillips Lab, Semicond Laser Branch, Kirtland AFB, NM 87117 USA. RP Lin, CH (reprint author), Univ Houston, Ctr Space Vacuum Epitaxy, Houston, TX 77204 USA. EM CHLin@uh.edu NR 19 TC 2 Z9 2 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 1071-1023 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD MAY-JUN PY 1998 VL 16 IS 3 BP 1435 EP 1438 DI 10.1116/1.589961 PG 4 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA ZV375 UT WOS:000074298300101 ER PT J AU Goss, SH Grazulis, L Tomich, DH Eyink, KG Walck, SD Haas, TW Thomas, DR Lampert, WV AF Goss, SH Grazulis, L Tomich, DH Eyink, KG Walck, SD Haas, TW Thomas, DR Lampert, WV TI Mechanical lithography using a single point diamond machining SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article; Proceedings Paper CT 16th North American Conference on Molecular Beam Epitaxy CY OCT 05-08, 1997 CL UNIV MICHIGAN, ANN ARBOR, MICHIGAN HO UNIV MICHIGAN ID SCANNING TUNNELING MICROSCOPE; BEAM EPITAXIAL-GROWTH; GAAS; SILICON; NANOINDENTATION; DAMAGE; FILMS AB A technique that produces submicron size features by machining GaAs wafers in air was studied. An apparatus was built which uses a sharp diamond tip to mechanically scribe patterns into the substrate. The debris produced from surface machining was removed by using a CO2 "snow jet" sprayer, thus eliminating the use of hazardous liquid chemicals for cleaning. By changing the force between the diamond tip and sample surface, different depths.of cuts were produced. This allowed the production of three dimensional patterns on the wafer in one step. With this instrument, write speeds of up to 25 mu m/s on 30 mu m x 30 mu m area patterns with a lateral resolution of 100 nm were demonstrated. In a different set of experiments, x-ray diffraction, spectroscopic ellipsometry, and cross sectional transmission electron microscopy analysis identified that subsurface damage created during the diamond turning process was removed at normal molecular beam epitaxial growth temperatures. Atomic force microscope analysis showed that the surface patterns were still present after annealing. C1 USAF, Mat & Mfg Directorate, Wright Patterson AFB, OH 45433 USA. RP Goss, SH (reprint author), USAF, Mat & Mfg Directorate, Wright Patterson AFB, OH 45433 USA. NR 22 TC 10 Z9 10 U1 0 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 1071-1023 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD MAY-JUN PY 1998 VL 16 IS 3 BP 1439 EP 1445 DI 10.1116/1.589962 PG 7 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA ZV375 UT WOS:000074298300102 ER PT J AU Tomich, DH Eyink, KG Seaford, ML Taferner, WF Tu, CW Lampert, WV AF Tomich, DH Eyink, KG Seaford, ML Taferner, WF Tu, CW Lampert, WV TI Atomic force microscopy correlated with spectroscopic ellipsometry during homepitaxial growth on GaAs(111)B substrates SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article; Proceedings Paper CT 16th North American Conference on Molecular Beam Epitaxy CY OCT 05-08, 1997 CL UNIV MICHIGAN, ANN ARBOR, MICHIGAN HO UNIV MICHIGAN ID MOLECULAR-BEAM EPITAXY; HOMOEPITAXIAL GROWTH; (111)B; SUPERLATTICES; GAAS AB The growth of high quality layers on GaAs(111)B on-axis substrates has been found to be extremely difficult. Homoepitaxial growth in the (root 19 x root 19)R23.4 reconstruction typically produces surfaces with pyramidal morphologies. Only a narrow region near the (root 19 x root 19)R23.4 and high temperature (1 x 1) border has been found to produce nearly atomically flat films. In this study, we have followed the homoepitaxial growth with in situ spectroscopic ellipsometry (SE) and compared the resulting film morphologies with atomic force microscopy (AFM). The surface reconstructions during growth were determined by reflection high energy electron diffraction. SE analysis allowed the determination of surface roughness variation which occurred under various growth conditions. Under near ideal growth conditions SE indicates the filling of voids evident after oxide desorption. When growths were carried out within the (root 19 x root 19)R23.4 reconstruction the surface was observed to roughen continuously with growth. AFM studies of these surfaces will be discussed in relation to the various stages of growth as observed with SE. The density of "triangular pits" on the surfaces grown under ideal conditions was found to be on the order of 1%. C1 USAF, Res Lab, Mech & Surface Interact Branch, Wright Patterson AFB, OH 45433 USA. Univ Calif San Diego, Dept Elect & Comp Engn, La Jolla, CA 92093 USA. RP Tomich, DH (reprint author), USAF, Res Lab, Mech & Surface Interact Branch, Wright Patterson AFB, OH 45433 USA. NR 12 TC 3 Z9 3 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 1071-1023 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD MAY-JUN PY 1998 VL 16 IS 3 BP 1479 EP 1483 DI 10.1116/1.589970 PG 5 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA ZV375 UT WOS:000074298300111 ER PT J AU Soref, RA Friedman, L Voon, LCLY Ram-Mohan, LR Sun, G AF Soref, RA Friedman, L Voon, LCLY Ram-Mohan, LR Sun, G TI Progress toward silicon-based intersubband lasers SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article; Proceedings Paper CT 16th North American Conference on Molecular Beam Epitaxy CY OCT 05-08, 1997 CL UNIV MICHIGAN, ANN ARBOR, MICHIGAN HO UNIV MICHIGAN AB Design results are presented for the quantum parallel laser (QPL) at 1-20 mu m wavelengths and the cryogenic 4-20 mu m quantum cascade laser (QCL), For 1-2 mu m lasing, the optimum multiple quantum well heterostructures are Si quantum wells (QWs) confined by wide-gap lattice-matched semiconductor layers, especially the Si/ZnS, Si/BeSeTe, Si/gamma-Al2O3, Si/CeO2, and Si/SiOx systems (SiOx is a crystalline suboxide). The electrically pumped 300 K unipolar p-i-p. QPL consists of tightly coupled QWs exhibiting coherent transport of carriers on superlattice (SL) minibands. A good QPL candidate is the symmetrically strained Ge-n-Si-n SL grown on relaxed Si0.5Ge0.5. Local-in-k population inversion is engineered between two valence minibands. Our calculations indicate that the p-i-p QCL is feasible in Ge-Si or in lattice-matched Si0.63Ge0.33C0.04/Si The oscillator strength f(z) = 0.1 calculated for the 8 ML x 8 ML Si/ZnS zone-folded SL is insufficient for 1.1 mu m band-to-band lasing; however, the in-plane dispersion of Si QWs in Si/ZnS SLs shows valence subbands that are sufficiently nonparabolic for local-in-k lasing in QPLs and QCLs. (C) 1998 American Vacuum Society. C1 USAF, Res Lab, Sensors Directorate, Hanscom AFB, MA 01731 USA. Worcester Polytech Inst, Dept Phys, Worcester, MA 01609 USA. Univ Massachusetts, Dept Phys, Boston, MA 02125 USA. RP Soref, RA (reprint author), USAF, Res Lab, Sensors Directorate, Hanscom AFB, MA 01731 USA. EM soref@maxwell.rl.plh.af.mil RI Ram-Mohan, Ramdas/C-5167-2012; Lew Yan Voon, Lok/I-8431-2012 OI Lew Yan Voon, Lok/0000-0001-5896-8119 NR 14 TC 5 Z9 5 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 1071-1023 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD MAY-JUN PY 1998 VL 16 IS 3 BP 1525 EP 1528 DI 10.1116/1.589979 PG 4 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA ZV375 UT WOS:000074298300121 ER PT J AU Meekin, GK AF Meekin, GK TI Intraoperative use of methylene blue to localize parathyroid adenoma SO LARYNGOSCOPE LA English DT Article ID GLANDS; IDENTIFICATION; INFUSION C1 USAF, Kessler Med Ctr, Dept Otolaryngol Head & Neck Surg, Keesler AFB, MS 39534 USA. RP Meekin, GK (reprint author), USAF, Kessler Med Ctr, Dept Otolaryngol Head & Neck Surg, 81st MG SGCSL,301 Fisher St,Rm-A132, Keesler AFB, MS 39534 USA. NR 15 TC 12 Z9 13 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 USA SN 0023-852X J9 LARYNGOSCOPE JI Laryngoscope PD MAY PY 1998 VL 108 IS 5 BP 772 EP 773 DI 10.1097/00005537-199805000-00027 PG 2 WC Medicine, Research & Experimental; Otorhinolaryngology SC Research & Experimental Medicine; Otorhinolaryngology GA ZM323 UT WOS:000073527000027 PM 9591562 ER PT J AU Puffer, RL AF Puffer, RL TI Air warriors: The inside story of the making of a navy pilot. SO LIBRARY JOURNAL LA English DT Book Review C1 USAF, Hist Prog, Edwards AFB, CA USA. RP Puffer, RL (reprint author), USAF, Hist Prog, Edwards AFB, CA 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 USA SN 0363-0277 J9 LIBR J JI Libr. J. PD MAY 1 PY 1998 VL 123 IS 8 BP 117 EP 117 PG 1 WC Information Science & Library Science SC Information Science & Library Science GA ZL850 UT WOS:000073478400109 ER PT J AU Carlson, JL AF Carlson, JL TI Children's museums: An American guidebook. SO LIBRARY JOURNAL LA English DT Book Review C1 Vandenberg AFB Lib, Vandenberg AFB, CA USA. RP Carlson, JL (reprint author), Vandenberg AFB Lib, Vandenberg AFB, CA USA. NR 1 TC 0 Z9 0 U1 0 U2 1 PU BOWKER MAGAZINE GROUP CAHNERS MAGAZINE DIVISION PI NEW YORK PA 249 W 17TH ST, NEW YORK, NY 10011 USA SN 0363-0277 J9 LIBR J JI Libr. J. PD MAY 1 PY 1998 VL 123 IS 8 BP 127 EP 128 PG 2 WC Information Science & Library Science SC Information Science & Library Science GA ZL850 UT WOS:000073478400153 ER PT J AU Solberg, LI Brekke, ML Kottke, TE Steel, RP AF Solberg, LI Brekke, ML Kottke, TE Steel, RP TI Continuous quality improvement in primary care: What's happening? SO MEDICAL CARE LA English DT Article DE total quality management; primary health care, questionnaires; knowledge, attitudes, practice; preventive health services; practice guidelines ID DOCTORS HELPING SMOKERS; HEALTH-CARE; MANAGEMENT; PRACTITIONERS; INTERVENTION; TRIAL; CQI AB OBJECTIVES. Despite much health care interest in quality and Continuous Quality Improvement, there is little quantitative information about it. The purpose of this study was to measure the attitudes, activities, and organizational cultures concerning Continuous Quality Improvement in a group of Midwestern primary care clinics. METHODS. Three surveys of the clinicians, nurses, and other staff in 44 primary care clinics in the metropolitan area of Minneapolis and St. Paul were conducted. These surveys assessed: (1) attitudes about quality improvement, (2) previous efforts in these clinics to use process improvement teams, and (3) the extent to which the clinics' organizational cultures were perceived as supporting quality. The Provider Attitude Survey was completed by clinicians and nurses; the Process Improvement Progress was completed by members of the best Continuous Quality Improvement teams, if any; and the Quality Systems Inventory was completed by all personnel. RESULTS. Most Of the clinical personnel reported support for various Continuous Quality Improvement concepts, but their understanding and experience were limited. Only 20 (45%) clinics had had at least one Continuous Quality Improvement team in the past, only five of the 12 teams with adequate information had completed an improvement cycle, and only seven reported improving a process with it. The mean clinic scores for quality culture were no better than those in other types of organizations. CONCLUSIONS. Despite relatively favorable attitudes and some Continuous Quality Improvement activities, there appears to be a need to help clinics build skill and experience for the required care improvements. C1 Hlth Partners Res Fdn, Minneapolis, MN 55440 USA. Brekke Associates, Minneapolis, MN USA. Mayo Clin, Dept Med, Rochester, MN USA. USAF, Inst Technol, Miamisburg, OH USA. RP Solberg, LI (reprint author), Hlth Partners Res Fdn, 8100 34th Ave S,POB 1309, Minneapolis, MN 55440 USA. EM leif.i.solberg@healthpart-ners.com FU AHRQ HHS [R01 HS08091] NR 33 TC 24 Z9 24 U1 1 U2 3 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 USA SN 0025-7079 J9 MED CARE JI Med. Care PD MAY PY 1998 VL 36 IS 5 BP 625 EP 635 DI 10.1097/00005650-199805000-00003 PG 11 WC Health Care Sciences & Services; Health Policy & Services; Public, Environmental & Occupational Health SC Health Care Sciences & Services; Public, Environmental & Occupational Health GA ZM940 UT WOS:000073591600003 PM 9596054 ER PT J AU Dutton, RE Semiatin, SL AF Dutton, RE Semiatin, SL TI The effect of density anisotropy on the yielding and flow behavior of partially consolidated powder compacts SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article ID PLASTICITY THEORY AB The effect of density anisotropy on the flow behavior of partially consolidated powder compacts of an alpha-two titanium aluminide alloy (Ti-24Al-11Nb) was established by conducting hot compression tests on samples made by hot die pressing or hot isostatic pressing ("hipping"). For the former consolidation method, in which anisotropic density distributions were developed, the upset tests were conducted both parallel and perpendicular to the die pressing direction. The flow stress results from these experiments, as well as those from the tests on the "hipped" material, were interpreted in terms of calculations of the stress intensification factor (phi). When the stress intensification factors were plotted as a function of areal relative density, rather than volumetric relative density, a unique dependence of phi on density was obtained. This dependence showed a smooth transition from a behavior measured by others for the early stages of densification to a behavior theoretically predicted for the latter stages of densification, in which isolated pores are closed. C1 USAF, Res Lab, AFRL MLLM, Mat & Mfg Directorate, Wright Patterson AFB, OH 45433 USA. RP Dutton, RE (reprint author), USAF, Res Lab, AFRL MLLM, Mat & Mfg Directorate, Wright Patterson AFB, OH 45433 USA. RI SEMIATIN, SHELDON/E-7264-2017 NR 14 TC 8 Z9 8 U1 0 U2 1 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 USA SN 1073-5623 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD MAY PY 1998 VL 29 IS 5 BP 1471 EP 1475 DI 10.1007/s11661-998-0362-0 PG 5 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA ZR054 UT WOS:000073931000012 ER PT J AU Wilkerson, JA Burton, MP AF Wilkerson, JA Burton, MP TI Inhalation of volatile substances: An emerging threat to readiness? SO MILITARY MEDICINE LA English DT Article ID PROPELLANTS; TOXICITY; DEATH; ABUSE AB Volatile substance abuse is the deliberate inhalation of volatile substances to achieve intoxication. We discuss the history and pathophysiological effects of commonly abused volatile substances. We explore three deaths and one serious accident in active duty military settings. The causes for abuse in the military environment are numerous and include remote duty, peer influence, low cost, rapid onset, limitation of ethanol use, difficult detection/screening for use, and lack of knowledge among users and authorities. The lethality of these substances and their casual use can constitute a threat to military readiness. Our experience suggests an increase in the use of these substances in the military paralleling their increasing use in the general population. Education and awareness training could limit fatalities and decrease the threat in military and civilian populations. C1 Wilford Hall USAF Med Ctr, Dept Pathol, Lackland AFB, TX 78236 USA. RP Wilkerson, JA (reprint author), Wilford Hall USAF Med Ctr, Dept Pathol, 2200 Bergquist Dr,Suite 1, Lackland AFB, TX 78236 USA. NR 11 TC 0 Z9 0 U1 1 U2 1 PU ASSN MILITARY SURG US PI BETHESDA PA 9320 OLD GEORGETOWN RD, BETHESDA, MD 20814 USA SN 0026-4075 J9 MIL MED JI Milit. Med. PD MAY PY 1998 VL 163 IS 5 BP 343 EP 345 PG 3 WC Medicine, General & Internal SC General & Internal Medicine GA ZM692 UT WOS:000073566300015 PM 9597853 ER PT J AU Hickman, TN Namnoum, AB Hinton, EL Zacur, HA Rock, JA AF Hickman, TN Namnoum, AB Hinton, EL Zacur, HA Rock, JA TI Timing of estrogen replacement therapy following hysterectomy with oophorectomy for endometriosis SO OBSTETRICS AND GYNECOLOGY LA English DT Article ID HORMONE AB Objective: To determine whether the immediate initiation of estrogen replacement therapy (ERT) in the postoperative period increases the incidence of symptom recurrence following total abdominal hysterectomy (TAH) with bilateral salpingo-oophorectomy (BSO) for the treatment of endometriosis. Methods: In a retrospective cohort study, 95 women who underwent TAH with BSO for endometriosis at the Johns Hopkins Hospital during 1979-1991 and who subsequently received ERT were identified by computer search. Follow-up information was obtained from medical records, outpatient charts, and telephone surveys. Pain recurrence in patients who started ERT within 6 weeks after surgery and in those who delayed ERT for more than 6 weeks was compared and adjusted for length of patient follow-up and other covariates. Results: Sixty women began ERT within the immediate postoperative period, and four (7%) of them had recurrent pain; 35 women began ERT more than 6 weeks after surgery, and seven (20%) of them had recurrent pain. The mean length of follow-up was 57 months. The difference in the crude rate of symptom recurrence following early and delayed initiation of ERT after TAH with BSO was not statistically significant (P = .09). Controlling for length of patient follow-up, no significant differences were observed between the two groups. Adjusting for covariates of stage, age, and postoperative adjunct medroxyprogesterone therapy, those who started ERT more than 6 weeks after surgery had a relative risk of 5.7 (95% confidence interval 1.3, 25.2) for pain recurrence. Conclusion: Although the number of patients in the study was too small to reach statistical significance in all analyses, these findings suggest that patients who begin ERT immediately after TAH with BSO are at no greater risk of recurrent pain than those who delay ERT for more than 6 weeks. (C) 1998 by The American College of Obstetricians and Gynecologists. C1 Johns Hopkins Sch Med, Div Reprod Endocrinol & Infertil, Baltimore, MD USA. Emory Univ, Sch Med, Dept Gynecol & Obstet, Atlanta, GA USA. RP Hickman, TN (reprint author), Wilford Hall USAF Med Ctr, Dept Obstet & Gynecol, Div Reprod Endocrinol & Infertil, 59th MDW MNO, 2200 Bergquist Dr,Suite 1, Lackland AFB, TX 78236 USA. NR 12 TC 26 Z9 28 U1 0 U2 0 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 0029-7844 J9 OBSTET GYNECOL JI Obstet. Gynecol. PD MAY PY 1998 VL 91 IS 5 BP 673 EP 677 DI 10.1016/S0029-7844(98)00071-4 PN 1 PG 5 WC Obstetrics & Gynecology SC Obstetrics & Gynecology GA ZJ801 UT WOS:000073254600006 PM 9572209 ER PT J AU Holck, DEE Dutton, JJ Wehrly, SR AF Holck, DEE Dutton, JJ Wehrly, SR TI Changes in astigmatism after ptosis surgery measured by corneal topography SO OPHTHALMIC PLASTIC AND RECONSTRUCTIVE SURGERY LA English DT Article DE ptosis; astigmatism; corneal topography; EyeSys topographic analyzer ID CONGENITAL PTOSIS; REFRACTIVE ERRORS; ANALYSIS SYSTEM; TRABECULECTOMY; ACCURACY; KERATOMETRY; ORBIT AB A computerized topographic analysis system (EyeSys [EyeSys Technologies, Houston, TX, U.S.A.]) was used to evaluate corneal astigmatic changes (central corneal power and astigmatic axis) after blepharoptosis surgery on 29 eyelids (22 patients). Fifteen nonoperated eyelids of study patients undergoing unilateral ptosis repair were used as controls. All patients were evaluated preoperatively and again 6 weeks after surgery. Fifteen operated eyelids and five controls were also examined 12 months after surgery to evaluate the stability of these measurements. In 72.4% of operated eyes, corneal topography demonstrated increased with-the-rule astigmatism 6 weeks after surgery, 13.8% of surgical eyes showed increasing against-the-rule astigmatism, and in 13.8%, no change was noted from preoperative measurements. None of the 15 control eyes demonstrated any change in corneal astigmatic axis or significant change in central corneal power. By 12 months after surgery, all of the operated eyes showed a regression toward the amount and pattern of preoperative astigmatism. Only two of 15 eyes maintained a difference of >0.3D of central corneal power greater than their preoperative measurement at 1 year. These data suggest that corneal topography may be altered by changes in eyelid position, although the changes appear to be temporary in most patients. C1 Wilford Hall USAF Med Ctr, Dept Ophthalmol, MKCO, Oculoplast Serv, San Antonio, TX 78236 USA. RP Holck, DEE (reprint author), Wilford Hall USAF Med Ctr, Dept Ophthalmol, MKCO, Oculoplast Serv, 2200 Bergquist Dr,Suite 1, San Antonio, TX 78236 USA. NR 21 TC 26 Z9 26 U1 0 U2 1 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 USA SN 0740-9303 J9 OPHTHALMIC PLAST REC JI Ophthalmic Plast. Reconstr. Surg. PD MAY PY 1998 VL 14 IS 3 BP 151 EP 158 PG 8 WC Ophthalmology; Surgery SC Ophthalmology; Surgery GA ZP336 UT WOS:000073742100001 PM 9612803 ER PT J AU Missey, MJ Dominic, V Myers, LE Eckardt, RC AF Missey, MJ Dominic, V Myers, LE Eckardt, RC TI Diffusion-bonded stacks of periodically poled lithium niobate SO OPTICS LETTERS LA English DT Article ID OPTICAL PARAMETRIC OSCILLATOR; LINBO3; WAVE AB We constructed diffusion-bonded stacks of periodically poled lithium niobate (PPLN). Such crystals combine the advantages of planar processing used to make PPLN wafers with the power handling capability of large apertures. We demonstrated an optical parametric oscillator that uses a 3-mm-thick diffusion-bonded stack consisting of three 1-mm-thick PPLN crystals. (C) 1998 Optical Society of America. C1 Univ Dayton, Ctr Electroopt, Dayton, OH 45469 USA. USAF, Res Lab, AFRL, SNJT, Wright Patterson AFB, OH 45433 USA. RP Missey, MJ (reprint author), Univ Dayton, Ctr Electroopt, Dayton, OH 45469 USA. NR 12 TC 32 Z9 32 U1 1 U2 3 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD MAY 1 PY 1998 VL 23 IS 9 BP 664 EP 666 DI 10.1364/OL.23.000664 PG 3 WC Optics SC Optics GA ZL010 UT WOS:000073389800004 PM 18087303 ER PT J AU Carretta, TR Doub, TW AF Carretta, TR Doub, TW TI Group differences in the role of g and prior job knowledge in the acquisition of subsequent job knowledge SO PERSONALITY AND INDIVIDUAL DIFFERENCES LA English DT Editorial Material DE general cognitive ability; job knowledge; causal models; sex and ethnic group differences; knowledge acquisition ID PERFORMANCE; ABILITY; ASVAB; VALIDITY AB The role of ability and prior job knowledge on the acquisition of subsequent job knowledge was examined for 41,976 participants in technical training. Comparisons were made for samples of men and women and for Whites, Blacks and Hispanics. Ability and prior job knowledge were measured prior to entering job training and subsequent job knowledge was measured at the completion of job training. The structural equation model that was used had been statistically confirmed and had shown a role for both ability and prior job knowledge. In all groups, the relative causal impact of ability was far greater than that of prior-job knowledge. It should be noted, however, that the relative causal impact of ability and prior job knowledge varied by group, being greater for women and Blacks. Contrary to expectations, prior job knowledge had virtually no causal role regarding the acquisition of subsequent job knowledge for women. The R-2 for predicting subsequent job knowledge was about equal for men and women, but less for Blacks than for Whites or Hispanics. Published by Elsevier Science Ltd. C1 USAF, Armstrong Lab AFMC, AFRL, HEAB,Res Lab,Human Effectiveness Directorate, Brooks AFB, TX 78235 USA. RP Carretta, TR (reprint author), USAF, Armstrong Lab AFMC, AFRL, HEAB,Res Lab,Human Effectiveness Directorate, 7909 Lindbergh Dr, Brooks AFB, TX 78235 USA. NR 25 TC 7 Z9 8 U1 1 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0191-8869 J9 PERS INDIV DIFFER JI Pers. Individ. Differ. PD MAY PY 1998 VL 24 IS 5 BP 585 EP 593 DI 10.1016/S0191-8869(97)00210-9 PG 9 WC Psychology, Social SC Psychology GA ZW029 UT WOS:000074366500001 ER PT J AU Tirre, WC Raouf, KK AF Tirre, WC Raouf, KK TI Structural models of cognitive and perceptual-motor abilities SO PERSONALITY AND INDIVIDUAL DIFFERENCES LA English DT Article ID INDIVIDUAL-DIFFERENCES; GENDER DIFFERENCES; SKILL ACQUISITION; WORKING-MEMORY; DETERMINANTS; PERFORMANCE AB A collection of 25 computer-administered tests was given to a sample of 172 adults to examine the overlap between the cognitive and perceptual-motor abilities domains. The focus was on multilimb coordination ability as a criterion variable, as this ability has a long history of validity in predicting pilot training performance. Structural equation modeling was used to test two related models of human abilities. The first one being a causal model and the second being a nested hierarchical model. The results suggest that multilimb coordination ability is not simply another manifestation of general cognitive ability, but instead the result of several abilities such as dynamic visual processing, visuo-spatial processing and working memory. A second narrower perceptual-motor factor, target tracking, was found to be related to processing speed but no other cognitive factor. Published by Elsevier Science Ltd. C1 USAF, HRAA, Armstrong Lab, Aircrew Training Res Div,Aircrew Performance Res, Brooks AFB, TX 78235 USA. RP Tirre, WC (reprint author), USAF, HRAA, Armstrong Lab, Aircrew Training Res Div,Aircrew Performance Res, 7909 Lindbergh Dr, Brooks AFB, TX 78235 USA. EM tirre@alhrm.brooks.af.mil NR 48 TC 9 Z9 11 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0191-8869 J9 PERS INDIV DIFFER JI Pers. Individ. Differ. PD MAY PY 1998 VL 24 IS 5 BP 603 EP 614 DI 10.1016/S0191-8869(98)80011-1 PG 12 WC Psychology, Social SC Psychology GA ZW029 UT WOS:000074366500003 ER PT J AU Rotondaro, MD Perram, GP AF Rotondaro, MD Perram, GP TI Role of rotational-energy defect in collisional transfer between the 5 P-2(1/2,3/2) levels in rubidium SO PHYSICAL REVIEW A LA English DT Article ID FINE-STRUCTURE TRANSITIONS; H-2 AB Steady-state laser-induced fluorescence techniques have been used to study the rates for energy transfer between the 5 P-2(1/2,3/2) levels in rubidium. The cross sections for collisions with the molecular species H-2, D-2, N-2, CH4, and CF4 have been measured as sigma(2)(P-2(1/2)-->P-2(3/2)) = 10.0, 21.4, 13.2, 29.5, and 9.5 x 10(-16) cm(2) and sigma(1)(P-2(3/2)-->P-2(1/2)) = 13.9, 29.8, 18.4, 41.0, and 13.2 x 10(-16) cm(2), respectively. Correlation of transfer probabilities with rotational-energy defect is demonstrated. these spin-orbit demonstrated. C1 USAF, Dept Engn Phys, Inst Technol, Wright Patterson AFB, OH 45433 USA. RP Rotondaro, MD (reprint author), USAF, Phillips Lab, LIDB, 3550 Aberdeen SE, Kirtland AFB, NM 87117 USA. OI Perram, Glen/0000-0002-4417-3929 NR 24 TC 15 Z9 15 U1 0 U2 3 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 MAY PY 1998 VL 57 IS 5 BP 4045 EP 4048 DI 10.1103/PhysRevA.57.4045 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA ZM869 UT WOS:000073584500112 ER PT J AU Roderick, NF Peterkin, RE Hussey, TW Spielman, RB Douglas, MR Deeney, C AF Roderick, NF Peterkin, RE Hussey, TW Spielman, RB Douglas, MR Deeney, C TI Hydromagnetic Rayleigh-Taylor instability in high-velocity gas-puff implosions SO PHYSICS OF PLASMAS LA English DT Article ID IMPLODING PLASMA LINERS; Z-PINCHES; SUPPRESSION; STABILITY AB Experiments using the Saturn pulsed power generator have produced high-velocity z-pinch plasma implosions with velocities over 100 cm/mu s using both annular and uniform-fill gas injection initial conditions. Both types of implosion show evidence of the hydromagnetic Rayleigh-Taylor instability with the uniform-fill plasmas producing a more spatially uniform pinch. Two-dimensional magnetohydrodynamic simulations including unsteady flow of gas from a nozzle into the diode region have been used to investigate these implosions. The instability develops from the nonuniform gas flow held that forms as the gas expands from the injection nozzle. Instability growth is limited to the narrow unstable region of the current sheath. For, the annular puff the unstable region breaks through the inner edge of the annulus increasing nonlinear growth as mass ejected from the bubble regions is not replenished by accretion. This higher growth leads to bubble thinning and disruption producing greater nonuniformity at pinch for the annular puff. The uniform puff provides gas to replenish bubble mass loss until just before pinch resulting in less bubble thinning and a more uniform pinch. C1 USAF, Res Lab, Kirtland AFB, NM 87117 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ New Mexico, Dept Chem & Nucl Engn, Albuquerque, NM 87131 USA. RP Roderick, NF (reprint author), USAF, Res Lab, Phillips Site, Kirtland AFB, NM 87117 USA. NR 35 TC 19 Z9 20 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD MAY PY 1998 VL 5 IS 5 BP 1477 EP 1484 DI 10.1063/1.872806 PN 1 PG 8 WC Physics, Fluids & Plasmas SC Physics GA ZM871 UT WOS:000073584700028 ER PT J AU Basu, B AF Basu, B TI Equatorial plasma instability in time-dependent equilibrium SO PHYSICS OF PLASMAS LA English DT Article; Proceedings Paper CT 39th Annual Meeting of the Division-of-Plasma-Physics of the American-Physical-Society CY NOV 17-21, 1997 CL PITTSBURGH, PENNSYLVANIA SP Amer Phys Soc, Div Plasma Phys ID SPREAD-F; WINDS; IONOSPHERE; REGION; FIELDS; MODES AB A theoretical model for plasma instability in the equatorial F region of the nighttime ionosphere that takes into account the time-dependent aspect of the ambient plasma, where the density gradient increases with time, and that allows variation of mode amplitudes both along the geomagnetic field line and along the vertical direction is presented. The instability is excited due to the combined effects of the gravity and an eastward electric field in the presence of a density gradient, and the time-dependent density gradient arises because of the E-0 X B-0 upward drift of the plasma and the decreasing (with altitude) recombination rate. The model is used to study the linear evolution of the instability and some results of the analysis are reported. The spatially localized plasma modes, predicted by the model, are consistent with the experimental observations. Due to the time-dependent density gradient, growth of the plasma modes is enhanced over what is obtained when the time dependence is ignored, and this enhancement increases with time. C1 USAF, Res Lab, Hanscom AFB, MA 01731 USA. RP Basu, B (reprint author), USAF, Res Lab, Hanscom AFB, MA 01731 USA. NR 18 TC 11 Z9 11 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD MAY PY 1998 VL 5 IS 5 SI SI BP 2022 EP 2028 DI 10.1063/1.872873 PN 2 PG 7 WC Physics, Fluids & Plasmas SC Physics GA ZN238 UT WOS:000073623700055 ER PT J AU Lonergan, GJ Pennington, DJ Morrison, JC Haws, RM Grimley, MS Kao, TC AF Lonergan, GJ Pennington, DJ Morrison, JC Haws, RM Grimley, MS Kao, TC TI Childhood pyelonephritis: Comparison of gadolinium-enhanced MR imaging and renal cortical scintigraphy for diagnosis SO RADIOLOGY LA English DT Article DE kidney, infection; kidney, MR; kidney, radionuclide studies; magnetic resonance (MR), comparative studies; radionuclide imaging, comparative studies; nephritis ID URINARY-TRACT INFECTION; TERM FOLLOW-UP; TC-99M-DMSA SCINTIGRAPHY; REFLUX NEPHROPATHY; ACID SCINTIGRAPHY; ESCHERICHIA-COLI; CHILDREN; DMSA; LOCALIZATION; EVOLUTION AB PURPOSE: To compare gadolinium-enhanced inversion-recovery magnetic resonance (MR) imaging with renal cortical scintigraphy in the diagnosis of childhood pyelonephritis. MATERIALS AND METHODS: Thirty-seven patients with fever-producing urinary tract infection underwent gadolinium-enhanced inversion-recovery MR imaging and technetium-99m renal cortical scintigraphy. Each study was read in double-blind fashion by two radiologists. The kidney was divided into three zones, and each was graded as positive, equivocal, or negative for pyelonephritis. RESULTS: Seventy kidneys (210 zones) were imaged. Twenty-six kidneys (54 zones) had evidence of pyelonephritis at both MR imaging and scintigraphy. Twenty-four kidneys (100 zones) were negative on both studies. Twelve kidneys (42 zones) were positive at MR imaging but negative at scintigraphy, and four kidneys (seven zones) were negative at MR imaging but positive at scintigraphy. The results of MR imaging for pyelonephritis were not equivalent to the results of scintigraphy (P = .001 for renal zones). The proportion of positive agreement between readers for the presence of pyelonephritis was 0.85 and 0.57 for MR imaging and scintigraphy, respectively. The proportion of negative agreement was 0.88 and 0.80 for MR imaging and scintigraphy, respectively. CONCLUSION: Gadolinium-enhanced inversion-recovery MR imaging enabled detection of more pyelonephritic lesions than did renal cortical scintigraphy and had superior interobserver agreement. C1 Wilford Hall USAF Med Ctr, Dept Diagnost Radiol, Lackland AFB, TX 78236 USA. Wilford Hall USAF Med Ctr, Dept Nucl Med, Lackland AFB, TX 78236 USA. Wilford Hall USAF Med Ctr, Dept Pediat, Lackland AFB, TX 78236 USA. Uniformed Serv Univ Hlth Sci, Dept Radiol & Nucl Med, Bethesda, MD 20814 USA. Uniformed Serv Univ Hlth Sci, Dept Prevent Med, Bethesda, MD 20814 USA. Armed Forces Inst Pathol, Dept Radiol Pathol, Washington, DC 20306 USA. RP Lonergan, GJ (reprint author), Wilford Hall USAF Med Ctr, Dept Diagnost Radiol, Lackland AFB, TX 78236 USA. NR 39 TC 61 Z9 62 U1 0 U2 0 PU RADIOLOGICAL SOC NORTH AMER PI EASTON PA 20TH AND NORTHAMPTON STS, EASTON, PA 18042 USA SN 0033-8419 J9 RADIOLOGY JI Radiology PD MAY PY 1998 VL 207 IS 2 BP 377 EP 384 PG 8 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA ZJ341 UT WOS:000073204300019 PM 9577484 ER PT J AU Wakin, MM AF Wakin, MM TI All that we can be: Black leadership and racial integration the army way SO SOCIETY LA English DT Book Review C1 USAF Acad, Colorado Springs, CO 80840 USA. RP Wakin, MM (reprint author), USAF Acad, Colorado Springs, CO 80840 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU TRANSACTION PERIOD CONSORTIUM PI NEW BRUNSWICK PA DEPT 3091 RUTGERS-THE STATE UNIV OF NJ, NEW BRUNSWICK, NJ 08903 USA SN 0147-2011 J9 SOCIETY JI Society PD MAY-JUN PY 1998 VL 35 IS 4 BP 87 EP 87 PG 1 WC Social Sciences, Interdisciplinary; Sociology SC Social Sciences - Other Topics; Sociology GA ZJ630 UT WOS:000073236000023 ER PT J AU Cheng, WX Virginia, RA Oberbauer, SF Gillespie, CT Reynolds, JF Tenhunen, JD AF Cheng, WX Virginia, RA Oberbauer, SF Gillespie, CT Reynolds, JF Tenhunen, JD TI Soil nitrogen, microbial biomass, and respiration along an arctic toposequence SO SOIL SCIENCE SOCIETY OF AMERICA JOURNAL LA English DT Article ID TUSSOCK TUNDRA; CLIMATE-CHANGE; ORGANIC-CARBON; ALASKAN TUNDRA; ERIOPHORUM-VAGINATUM; VEGETATION TYPES; PLANT NUTRITION; BROOKS-RANGE; GROWTH; WATER AB To investigate the interactions among mineral N, C availability, microbial biomass, and respiration in arctic soils, we sampled soils five times during a growing season from a toposequence on a slope in northern Alaska. The toposequence consisted of six vegetative types from the ridge top to the stream bank: lichen heath, dry cassiope, moist carer (Carex spp.), water track, tussock tundra (intertussock), and riparian. The spatial distribution and temporal variation of soil mineral N, microbial biomass, soil C availability, and C turnover were soil type dependent. During the growing season, the concentration of soil NH4+-N decreased in tussock tundra soils but increased in lichen heath soils. Soil C availability at all locations was the highest at the beginning of the growing season and declined thereafter. The C availability index (CAI) and the potential C turnover rate increased as soils became wetter. Tussock-forming tundra soil was generally colder than other sites and had high C/N ratios, low amounts of mineral N, and a low potential C turnover index, and therefore, was the least biologically active type. In contrast, water track was the most biologically active site in the sequence and had the highest C and N availability, the highest potential C turnover index, and the highest microbial biomass C and N. The mosaic of diverse plant communities and soil types that comprise arctic landscapes necessitates that accurate estimates of large-scale C or N budget can only be made by integration of all types of plant communities and soils. C1 Univ Nevada, Desert Res Inst, Ctr Biol Sci, Reno, NV 89506 USA. Dartmouth Coll, Environm Studies Program, Hanover, NH 03755 USA. Florida Int Univ, Dept Biol Sci, Miami, FL 33199 USA. CEVN, CES 730, Vandenberg AFB, CA 93437 USA. Duke Univ, Dept Bot, Durham, NC 27708 USA. Univ Bayreuth, Bayreuther Inst Okosyst Forsch, D-8580 Bayreuth, Germany. RP Cheng, WX (reprint author), Univ Nevada, Desert Res Inst, Ctr Biol Sci, POB 60220, Reno, NV 89506 USA. RI Reynolds, James/G-6364-2010; Cheng, Weixin/F-4968-2011 OI Cheng, Weixin/0000-0003-2964-2376 NR 50 TC 30 Z9 32 U1 3 U2 13 PU SOIL SCI SOC AMER PI MADISON PA 677 SOUTH SEGOE ROAD, MADISON, WI 53711 USA SN 0361-5995 J9 SOIL SCI SOC AM J JI Soil Sci. Soc. Am. J. PD MAY-JUN PY 1998 VL 62 IS 3 BP 654 EP 662 PG 9 WC Soil Science SC Agriculture GA ZZ128 UT WOS:000074698500016 ER PT J AU Zhou, W Sheu, S Liou, JJ Huang, CI AF Zhou, W Sheu, S Liou, JJ Huang, CI TI A multi-emitter finger AlGaAs/GaAs HBT model including the effects of two-dimensional temperature distribution on emitter fingers SO SOLID-STATE ELECTRONICS LA English DT Article ID HETEROJUNCTION BIPOLAR-TRANSISTORS AB Two-dimensional temperature distribution on the emitter fingers of multi-finger AlGaAs/GaAs heterojunction bipolar transistors (HBTs) is studied, and a model including such effects was developed to describe the HBT behavior and performance, such as the d.c. current gain and cutoff frequency. Device design issues such as the number of fingers, finger spacing, and finger dimension were considered. Results obtained from measurements and simulated from a three-dimensional device simulator are included in support of the model. Further, the present model is compared against the conventional model to assess the degree of inaccuracy caused by the use of one-dimensional temperature profile in HBT modeling. (C) 1998 Elsevier Science Ltd. C1 Univ Cent Florida, Dept Elect & Comp Engn, Orlando, FL 32816 USA. USAF, Wright Lab, Electron Device Div, Wright Patterson AFB, OH 45433 USA. RP Zhou, W (reprint author), Univ Cent Florida, Dept Elect & Comp Engn, Orlando, FL 32816 USA. NR 14 TC 8 Z9 9 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-1101 J9 SOLID STATE ELECTRON JI Solid-State Electron. PD MAY PY 1998 VL 42 IS 5 BP 693 EP 698 DI 10.1016/S0038-1101(97)00172-X PG 6 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA ZT931 UT WOS:000074142500002 ER PT J AU Hallowell, SF Harker, PT AF Hallowell, SF Harker, PT TI Predicting on-time performance in scheduled railroad operations: Methodology and application to train scheduling SO TRANSPORTATION RESEARCH PART A-POLICY AND PRACTICE LA English DT Article DE railroads; stochastic scheduling; computer assisted dispatching ID FREIGHT RAILROADS AB In previous work, the authors developed an analytical line delay model for analyzing rail line-haul operations, and validated the model as a predictive tool. This paper examines the application of the model as a prescriptive tool for the generation of train schedules. A unique feature of the model is that it incorporates dynamic meet/pass priorities in order to approximate an optimal meet/pass planning process. Extensive Monte Carlo simulations are conducted to examine the application of the model for adjusting real-world schedules to improve on-time performance and reduce delay. This empirical work represents the first attempt to investigate the impacts of the scheduling methodology on on-time line-haul performance. The problems are based on historical data from a major North American railroad. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 Univ Penn, Dept Operat & Informat Management, Philadelphia, PA 19104 USA. USAF, Operat Res Grp, Arlington, VA 22227 USA. RP Harker, PT (reprint author), Univ Penn, Dept Operat & Informat Management, Philadelphia, PA 19104 USA. RI Harker, Patrick/A-9467-2013 OI Harker, Patrick/0000-0003-0659-3102 NR 23 TC 23 Z9 23 U1 3 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0965-8564 J9 TRANSPORT RES A-POL JI Transp. Res. Pt. A-Policy Pract. PD MAY PY 1998 VL 32 IS 4 BP 279 EP 295 DI 10.1016/S0965-8564(97)00009-8 PG 17 WC Economics; Transportation; Transportation Science & Technology SC Business & Economics; Transportation GA ZY305 UT WOS:000074606800005 ER PT J AU John, PJ Liang, J Cutler, JN AF John, P. J. Liang, J. Cutler, J. N. TI Surface activity of high-temperature perfluoropolyalkylether oil additives SO TRIBOLOGY LETTERS LA English DT Article DE fluorine; additive; XPS; tribology AB Three additive materials for perfluoropolyalkylether-based high-temperature engine oils were studied, a bis-substituted dibenzothiazole, a diphenyl ether and a triphenyl phosphine. The focus of this work was to understand how the additives interacted with various surfaces to provide either anticorrosion or antiwear activity. In the case of the bis-substituted dibenzothiazole, the additive was found to form a thick, protective anticorrosion layer on the surface. The diphenyl ether served as another equally effective anticorrosion additive but failed to demonstrate surface activity. The third additive compound, triphenyl phosphine, was found to break down at the surface and form an inorganic polyphosphate which provided a level of both anticorrosion and antiwear function. C1 [John, P. J.; Liang, J.] Univ Dayton, Res Inst, Dayton, OH 45469 USA. [Cutler, J. N.] Wright Lab, WL MLBT, Mat Directorate, Wright Patterson AFB, OH 45433 USA. RP John, PJ (reprint author), Univ Dayton, Res Inst, Dayton, OH 45469 USA. FU Materials Directorate of Wright Laboratory, Wright-Patterson Air Force Base, OH; Air Force Office of Scientific Research, Bolling Air Force Base, DC FX This work was supported by the Materials Directorate of Wright Laboratory, Wright-Patterson Air Force Base, OH and the Air Force Office of Scientific Research, Bolling Air Force Base, DC. NR 25 TC 5 Z9 5 U1 1 U2 1 PU SPRINGER/PLENUM PUBLISHERS PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1023-8883 J9 TRIBOL LETT JI Tribol. Lett. PD MAY PY 1998 VL 4 IS 3-4 BP 277 EP 285 DI 10.1023/A:1019179927369 PG 9 WC Engineering, Chemical; Engineering, Mechanical SC Engineering GA V17SK UT WOS:000207956700008 ER PT J AU Christe, KO Wilson, WW AF Christe, KO Wilson, WW TI Dinitramide anion as a reagent for the controlled replacement of fluorine by oxygen in halogen fluorides SO JOURNAL OF FLUORINE CHEMISTRY LA English DT Article DE fluorine-oxygen exchange; dinitramide anion; halogen fluorides; bromine pentafluoride; chlorine pentafluoride; iodine heptafluoride AB The reactions of KN(NO2)(2) with BrF5, ClF5 and IF7 were investigated. It is shown that the N(NO2)(2)(-) anion is superior to NO3- as a reagent for the controlled, stepwise replacement of two fluorine ligands by a doubly bonded oxygen atom. Thus, KN(NO2)(2) readily reacts with BrF5 at -45 degrees C to give KBrOF4, N2O and FNO2 in quantitative yield. With ClF5 at -13 degrees C, an equimolar mixture of KClOF4 and KClF4 was obtained. The formation of KClOF4 is remarkable because with most other fluorine-oxygen exchange reagents, such as NO3-, the exchange process cannot be arrested at the ClOF4- stage and yields FClO2 as the only product. In the case of IF7, deoxygenation of the desired IOF6- product occurred resulting instead in the formation of KIF6 which, in the presence of excess IF7, formed the novel KIF6 . 2IF(7) adduct. (C) 1998 Elsevier Science S.A. All lights reserved. C1 USAF, Propuls Directorate, Raytheon STX, Edwards AFB, CA 93524 USA. Univ So Calif, Loker Hydrocarbon Res Inst, Los Angeles, CA 90089 USA. RP Christe, KO (reprint author), USAF, Propuls Directorate, Raytheon STX, Edwards AFB, CA 93524 USA. RI Christe, Karl/O-4885-2014 OI Christe, Karl/0000-0003-0661-5519 NR 15 TC 2 Z9 2 U1 0 U2 3 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0022-1139 J9 J FLUORINE CHEM JI J. Fluor. Chem. PD APR 30 PY 1998 VL 89 IS 1 BP 97 EP 99 DI 10.1016/S0022-1139(98)00092-X PG 3 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA ZJ736 UT WOS:000073247800017 ER PT J AU De Rosa, ME Tondiglia, VP Natarajan, LV AF De Rosa, ME Tondiglia, VP Natarajan, LV TI Mechanical deformation of a liquid crystal diffraction grating in an elastic polymer SO JOURNAL OF APPLIED POLYMER SCIENCE LA English DT Article DE shear; polymer dispersed liquid crystal; diffraction grating; hologram; elastic ID BRAGG GRATINGS AB We demonstrate the tuning of the diffraction efficiency in a polymer-dispersed liquid crystal (PDLC) diffraction grating by mechanical shear deformation. We chose a photocurable thermoset with elastic mechanical properties as the host material to demonstrate the tuning effect. Raman-Nath gratings were prepared by anisotropically curing a mixture of commercial photopolymer doped with Liquid crystal. The mixture was contained between glass slides which were mounted in a simple shearing device. During the photopolymerization, the liquid crystal phase separated into 2-mu m droplets organized into channels with 3.8-mu m spacing. Gratings were deformed by shearing the samples in a direction perpendicular to the channel orientation. The diffraction intensity and morphology were monitored as a function of shear strain. Reversible tuning was observed due to the elastic nature of the matrix. (C) 1998 John Wiley & Sons, Inc. C1 USAF, Wright Lab, Mat Directorate, WL MLPJ, Wright Patterson AFB, OH 45433 USA. Sci Applicat Int Corp, Dayton, OH 45431 USA. RP De Rosa, ME (reprint author), USAF, Wright Lab, Mat Directorate, WL MLPJ, 3005 P St,Suite 1, Wright Patterson AFB, OH 45433 USA. NR 8 TC 7 Z9 7 U1 2 U2 3 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0021-8995 J9 J APPL POLYM SCI JI J. Appl. Polym. Sci. PD APR 25 PY 1998 VL 68 IS 4 BP 523 EP 526 DI 10.1002/(SICI)1097-4628(19980425)68:4<523::AID-APP2>3.0.CO;2-O PG 4 WC Polymer Science SC Polymer Science GA ZD945 UT WOS:000072741500002 ER PT J AU Munichandraiah, N Scanlon, LG Marsh, RA AF Munichandraiah, N Scanlon, LG Marsh, RA TI Surface films of lithium: an overview of electrochemical studies SO JOURNAL OF POWER SOURCES LA English DT Article DE lithium; surface film; electron-transfer reaction; DC polarization; AC impedance ID IMPEDANCE SPECTROSCOPY; LI/LI+ COUPLE; ELECTROLYTES; MODEL; MICROELECTRODE; INTERFACE; INTERPHASE; ELECTRODES; SYSTEMS AB There is considerable ambiguity in the literature about the importance of lithium surface film on the electrochemical reaction at the lithium/electrolyte interface. Some studies attribute the measured interfacial properties to the surface film on lithium alone and other studies consider the measured properties due entirely to electron-transfer reaction; while a few studies provide due recognition to both the surface film as well as the charge-transfer reaction. Literature on DC polarization and AC impedance spectroscopic studies of Li/non-aqueous liquid and solid polymer electrolyte interface is reviewed. Our electrochemical impedance spectroscopic studies of lithium/solid polymer electrolyte interface are analyzed using simple equivalent circuit models. The models include both the surface film properties as well as the electron-transfer reaction. The experimental results and reviewed literature support that both the surface film on lithium and the electron-transfer reaction are equally important interfacial phenomena, and should be considered simultaneously during an investigation. (C) 1998 Elsevier Science S.A. C1 Indian Inst Sci, Dept Inorgan & Phys Chem, Bangalore 560012, Karnataka, India. Wright Lab, Battery Electrochem Sect, Wright Patterson AFB, OH 45433 USA. RP Munichandraiah, N (reprint author), Indian Inst Sci, Dept Inorgan & Phys Chem, Bangalore 560012, Karnataka, India. NR 26 TC 68 Z9 69 U1 1 U2 24 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0378-7753 J9 J POWER SOURCES JI J. Power Sources PD APR 21 PY 1998 VL 72 IS 2 BP 203 EP 210 DI 10.1016/S0378-7753(97)02771-7 PG 8 WC Chemistry, Physical; Electrochemistry; Energy & Fuels; Materials Science, Multidisciplinary SC Chemistry; Electrochemistry; Energy & Fuels; Materials Science GA ZV305 UT WOS:000074291300016 ER PT J AU Roberson, SL Finello, D Davis, RF AF Roberson, SL Finello, D Davis, RF TI Growth of MoxN films via chemical vapor deposition of MoCl5 and NH3 SO SURFACE & COATINGS TECHNOLOGY LA English DT Article DE molybdenum nitride; chemical vapour deposition; electrodes; tribological coatings ID NITRIDE THIN-FILMS; MOLYBDENUM NITRIDE; HYDRODENITROGENATION; GAMMA-MO2N; QUINOLINE; CARBIDES; COATINGS; NITROGEN; MO2N AB Polycrystalline MoxN (x=1 or 2) films have been grown via chemical vapor deposition on 50 mu m thick polycrystalline Ti substrates using molybdenum pentachloride (MoCl5) and anhydrous ammonia (NH3) in a cold-wall vertical pancake-style reactor. X-ray diffraction data indicated that a two-phase MoxN assemblage consisting of gamma-Mo2N and delta-MoN was present in films deposited above 400 degrees C. The percentages of gamma-Mo2N and delta-MoN in the films decreased and increased, respectively, as the deposition temperature increased at constant NH3, flow rates and deposition pressures. The surface macrostructure of the as-deposited films was independent of the deposition temperature and was very similar to that of the uncoated Ti substrate, However, the microstructure of the films varied with the deposition temperature. Energy dispersive X-ray data indicated that films deposited at and above 400 degrees C did not contain detectable levels of chlorine. (C) 1998 Elsevier Science S.A. C1 N Carolina State Univ, Dept Mat Sci & Engn, Raleigh, NC 27695 USA. USAF, Res Labs, Munit Directorate, Eglin AFB, FL 32542 USA. RP Roberson, SL (reprint author), N Carolina State Univ, Dept Mat Sci & Engn, Box 7907, Raleigh, NC 27695 USA. RI Davis, Robert/A-9376-2011 OI Davis, Robert/0000-0002-4437-0885 NR 13 TC 17 Z9 17 U1 0 U2 8 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0257-8972 J9 SURF COAT TECH JI Surf. Coat. Technol. PD APR 21 PY 1998 VL 102 IS 3 BP 256 EP 259 DI 10.1016/S0257-8972(98)00448-4 PG 4 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA ZR798 UT WOS:000074014800010 ER PT J AU Ruyten, WM Smith, MS Price, LL Williams, WD AF Ruyten, WM Smith, MS Price, LL Williams, WD TI Three-line fluorescence thermometry of optically thick shock-tunnel flow SO APPLIED OPTICS LA English DT Article ID NO; TEMPERATURE AB Two-line fluorescence thermometry measurements based on excitation of the A-X (0, 0) band of nitric oxide were performed in the free-stream flow of a large-scale shock tunnel, the Arnold Engineering Development Center Impulse Facility. Because the flow is optically thick, effects of laser absorption must be taken into account. This can be accomplished by extending the two-line thermometry concept to three lines. We illustrate the three-line technique by combining two-line planar laser-induced fluorescence measurements from separate facility runs. The resulting free-stream temperature T-0 = 468 K +/- 65 K is insensitive to assumptions regarding the laser propagation distance through the flow, the vibrational temperature of the flow, and the precise nature of the absorption line shape. C1 Sverdrup Technol Inc, Arnold Engn Dev Ctr Grp, Appl Technol Dept, Instrumentat & Diagnost Branch, Arnold AFB, TN 37389 USA. RP Ruyten, WM (reprint author), Sverdrup Technol Inc, Arnold Engn Dev Ctr Grp, Appl Technol Dept, Instrumentat & Diagnost Branch, Arnold AFB, TN 37389 USA. NR 14 TC 2 Z9 2 U1 0 U2 1 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD APR 20 PY 1998 VL 37 IS 12 BP 2334 EP 2339 DI 10.1364/AO.37.002334 PG 6 WC Optics SC Optics GA ZH797 UT WOS:000073148600020 PM 18273160 ER PT J AU De Long, H Hussey, C Osteryoung, R Wilkes, J AF De Long, H Hussey, C Osteryoung, R Wilkes, J TI Designer solvents SO CHEMICAL & ENGINEERING NEWS LA English DT Letter C1 USAF, Off Sci Res, Washington, DC 20330 USA. Univ Mississippi, University, MS 38677 USA. N Carolina State Univ, Raleigh, NC 27695 USA. USAF Acad, Colorado Springs, CO 80840 USA. RP De Long, H (reprint author), USAF, Off Sci Res, Washington, DC 20330 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0009-2347 J9 CHEM ENG NEWS JI Chem. Eng. News PD APR 20 PY 1998 VL 76 IS 16 BP 8 EP 8 PG 1 WC Chemistry, Multidisciplinary; Engineering, Chemical SC Chemistry; Engineering GA ZJ244 UT WOS:000073194600004 ER PT J AU English, JC Canchola, DR Finley, EM AF English, JC Canchola, DR Finley, EM TI Axillary basal cell carcinoma: A need for full cutaneous examination SO AMERICAN FAMILY PHYSICIAN LA English DT Article ID MOHS MICROGRAPHIC SURGERY; NONMELANOMA SKIN-CANCER; MALIGNANT-MELANOMA; UNITED-STATES; DERMATOLOGY PATIENTS; SELF-EXAMINATION; RISK-FACTORS; YIELD AB Basal cell carcinoma is the mast common skin malignancy While this lesion most often occurs in sun-exposed areas of the skin, it can also develop in sites that are not usually exposed to sunlight or artificial ultraviolet radiation, such as the breast, palm or groin. A periodic complete examination of the skin should be performed to ensure that atypical presentations of basal cell carcinoma are not overlooked or misdiagnosed. Treatment options include curettage and desiccation, cryosurgery; surgical excision, radiotherapy and Mohs micrographic surgery. C1 Wilford Hall USAF Med Ctr, Brooke Army Med Ctr, Dept Dermatol, San Antonio, TX 78236 USA. RP English, JC (reprint author), 1940 Avalon Ct, Colorado Springs, CO 80919 USA. NR 34 TC 7 Z9 7 U1 0 U2 0 PU AMER ACAD FAMILY PHYSICIANS PI KANSAS CITY PA 8880 WARD PARKWAY, KANSAS CITY, MO 64114-2797 USA SN 0002-838X J9 AM FAM PHYSICIAN JI Am. Fam. Physician PD APR 15 PY 1998 VL 57 IS 8 BP 1860 EP 1864 PG 5 WC Primary Health Care; Medicine, General & Internal SC General & Internal Medicine GA ZJ827 UT WOS:000073257700015 PM 9575324 ER PT J AU Mracek, CP Cloutier, JR AF Mracek, CP Cloutier, JR TI Control designs for the nonlinear benchmark problem via the state-dependent Riccati equation method SO INTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL LA English DT Article AB A nonlinear control problem has been posed by Bupp et al.(1) to provide a benchmark for evaluating various nonlinear control design techniques. In this paper, the capabilities of the state-dependent Riccati equation (SDRE) technique are illustrated in producing two control designs for the benchmark problem. The SDRE technique represents a systematic way of designing nonlinear regulators. The design procedure consists of first using direct parameterization to bring the nonlinear system to a linear structure having state-dependent coefficients (SDC). A state-dependent Riccati equation is then solved at each point x along the trajectory to obtain a nonlinear feedback controller of the form u = -R-1(x)B-T(x)P(x)x, where P(x) is the solution of the SDRE. Analysis of the first design shows that in the absence of disturbances and uncertainties, the SDRE nonlinear feedback solution compares very favorably to the optimal open-loop solution of the posed nonlinear regulator problem, the latter being obtained via numerical optimization. It is also shown via simulation that the closed-loop system has stability robustness against parametric variations and attenuates sinusoidal disturbances. In the second design it is demonstrated how a hard bound can be imposed on the control magnitude to avoid actuator saturation. (C) 1998 John Wiley & Sons, Ltd. C1 USAF, Res Lab, Munit Directorate, Eglin AFB, FL 32542 USA. RP Mracek, CP (reprint author), USAF, Res Lab, Munit Directorate, Eglin AFB, FL 32542 USA. NR 19 TC 139 Z9 145 U1 1 U2 17 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 1049-8923 J9 INT J ROBUST NONLIN JI Int. J. Robust Nonlinear Control PD APR 15 PY 1998 VL 8 IS 4-5 BP 401 EP 433 DI 10.1002/(SICI)1099-1239(19980415/30)8:4/5<401::AID-RNC361>3.0.CO;2-U PG 33 WC Automation & Control Systems; Engineering, Electrical & Electronic; Mathematics, Applied SC Automation & Control Systems; Engineering; Mathematics GA ZG432 UT WOS:000073001600008 ER PT J AU Huang, DH Lyo, SK AF Huang, DH Lyo, SK TI Magnetically tuned wide-band quantum well infrared photodetectors SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID INTERSUBBAND TRANSITIONS; MULTIQUANTUM WELLS; DETECTOR; GAAS/ALGAAS; MODULATION AB The electron eigenstates of double quantum well system in an in-plane magnetic field are calculated accurately using the density-functional theory which includes the Coulomb interaction between electrons. The absorption coefficient as a function of the probe photon energy is further calculated using the self-consistent-held theory which takes into account many-body effects on the optical intersubband transitions. The dependence of the absorption spectra on the magnetic field, temperature, electron density, well and middle-barrier widths, quantum-well symmetry, and electric field has been studied extensively. It provides an unconventional approach for designing a tunable wide-band quantum well infrared photodetector by applying an in-plane magnetic field. C1 USAF, Phillips Lab, PL, TMR, Kirtland AFB, NM 87117 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Huang, DH (reprint author), USAF, Phillips Lab, PL, TMR, 3550 Aberdeen Ave SE,Bldg 426, Kirtland AFB, NM 87117 USA. EM huangd@plk.af.mil NR 25 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 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 15 PY 1998 VL 83 IS 8 BP 4531 EP 4539 DI 10.1063/1.367216 PG 9 WC Physics, Applied SC Physics GA ZJ989 UT WOS:000073273900085 ER PT J AU Tan, LS Srinivasan, KR Bai, SJ Spry, RJ AF Tan, LS Srinivasan, KR Bai, SJ Spry, RJ TI New aromatic benzazole polymers - II: Synthesis and conductivity of benzobisthiazole-co-polymers incorporated with 4-N,N-dimethylaminotriphenylamine groups SO JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY LA English DT Article DE poly(benzobisthiazole); copolymers; 4-N,N-dimethylaminotriphenylamine; conducting polymers; iodine doping ID RIGID-ROD POLYMERS; CONJUGATED POLYMER; OPTICAL-PROPERTIES; POLYANILINE AB New aromatic benzobisthiazole copolymers containing 10-70 mol % of 4-N,N-dimethylamino-triphenylamine functionality were prepared from the respective dinitrile or dicarboxylic acid monomers, terephthalic acid, and 2,5-diamino-1,4-benzenedithiol dihydrochloride in polyphosphoric acid. At the first approximation, the copolymers containing 10 mol % or less of the triarylamino moieties in the polymer chains still preserve the capability to form anisotropic (nematic) solutions at 10 wt % polymer concentration. This is an important requirement for processing the copolymers into fibers and films with good to excellent mechanical properties. Films with good mechanical integrity were cast from the dilute methanesulfonic acid solutions of the copolymers under reduced pressure. They showed electrical conductivity values of the order of 10(-11)-10(-10) S/cm in pristine state, with four to seven orders of magnitude increase upon exposure to mild oxidizing agents such as iodine vapor. On the contrary, the parent polymer, poly(p-phenylene benzobisthiazole) is an insulator with conductivity of less than 10(-12) S/cm, and its conductivity does not improve at all with exposure to iodine vapor. (C) 1998 John Wiley & Sons, Inc. C1 Wright Lab, Mat Directorate, WL MLBP, Polymer Branch, Wright Patterson AFB, OH 45433 USA. SYSTRAN Corp, Dayton, OH 45432 USA. Univ Dayton, Res Inst, Dayton, OH 45469 USA. RP Tan, LS (reprint author), Wright Lab, Mat Directorate, WL MLBP, Polymer Branch, 2941 P St,Suite 1, Wright Patterson AFB, OH 45433 USA. OI Tan, Loon-Seng/0000-0002-2134-9290 NR 24 TC 10 Z9 10 U1 1 U2 4 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0887-624X J9 J POLYM SCI POL CHEM JI J. Polym. Sci. Pol. Chem. PD APR 15 PY 1998 VL 36 IS 5 BP 713 EP 724 DI 10.1002/(SICI)1099-0518(19980415)36:5<713::AID-POLA5>3.0.CO;2-M PG 12 WC Polymer Science SC Polymer Science GA YY905 UT WOS:000072199700005 ER PT J AU Lee, MK Cowan, WD Welsh, BH Bright, VM Roggemann, MC AF Lee, MK Cowan, WD Welsh, BH Bright, VM Roggemann, MC TI Aberration-correction results from a segmented microelectromechanical deformable mirror and a refractive lenslet array SO OPTICS LETTERS LA English DT Article AB Quadratic aberration is successfully corrected with a segmented microelectromechanical deformable mirror in conjunction with a refractive lenslet array. Use of the lenslet array greatly improves the effective fill factor of the correcting element. Experimental results show correction approaching the diffraction limit for an extreme spherical aberration. (C) 1998 Optical Society of America. C1 USAF, Inst Technol, Dept Elect & Comp Engn, Wright Patterson AFB, OH 45433 USA. Univ Colorado, Dept Mech Engn, Boulder, CO 80309 USA. Michigan Technol Univ, Dept Elect Engn, Houghton, MI 49931 USA. RP Lee, MK (reprint author), USAF, Inst Technol, Dept Elect & Comp Engn, 2950 P St, Wright Patterson AFB, OH 45433 USA. NR 2 TC 19 Z9 19 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD APR 15 PY 1998 VL 23 IS 8 BP 645 EP 647 DI 10.1364/OL.23.000645 PG 3 WC Optics SC Optics GA ZG942 UT WOS:000073055500027 PM 18084604 ER PT J AU Szmulowicz, F AF Szmulowicz, F TI Numerically stable secular equation for superlattices via transfer-matrix formalism and application to InAs/In0.23Ga0.77Sb and InAs/In0.3Ga0.7Sb/GaSb superlattices SO PHYSICAL REVIEW B LA English DT Article ID ENVELOPE-FUNCTION APPROXIMATION; DOT-P METHOD; ELECTRONIC-STRUCTURE; INFRARED DETECTORS; GENERAL EXPRESSION; SEMICONDUCTOR; MICROSTRUCTURES; HETEROSTRUCTURES; DERIVATION; ABSORPTION AB The numerically stable, Hermitian secular equation for superlattices within the envelope-function approximation [F. Szmulowicz, Phys. Rev. B 54, 11 539 (1996)] is derived via the transfer-matrix approach using Burt's boundary conditions. In the process, the tangents-only form of the secular equation is related to an earlier transfer matrix approach [L. R. Ram-Mohan, K. H. Yoo, and R. L. Aggarwal, Phys. Rev. B 38, 6151 (1988)] and extended to structures with an arbitrary number of layers per superlattice period. The formalism is applied to superlattices with two (InAs/In0.23Ga0.77Sb) and three (InAs/In0.3Ga0.7Sb/GaSb) layers per superlattice period, which are of interest for infrared detector and infrared cascade-laser applications, respectively. [S0163-1829(98)03015-X]. C1 Wright Lab, Mat Directorate, WL MLPO, Wright Patterson AFB, OH 45433 USA. Univ Dayton, Res Inst, Dayton, OH 45469 USA. RP Szmulowicz, F (reprint author), Wright Lab, Mat Directorate, WL MLPO, Wright Patterson AFB, OH 45433 USA. NR 31 TC 19 Z9 19 U1 0 U2 0 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 APR 15 PY 1998 VL 57 IS 15 BP 9081 EP 9087 DI 10.1103/PhysRevB.57.9081 PG 7 WC Physics, Condensed Matter SC Physics GA ZJ480 UT WOS:000073219900056 ER PT J AU Hasselbeck, MP Enders, PM AF Hasselbeck, MP Enders, PM TI Electron-electron interactions in the nonparabolic conduction band of narrow-gap semiconductors SO PHYSICAL REVIEW B LA English DT Article ID FREE-CARRIER ABSORPTION; BALLISTIC TRANSPORT; DIELECTRIC FUNCTION; PHONON MODES; SCATTERING; TEMPERATURE; TRANSISTORS; GAAS; DEVICES AB The Lindhard dielectric function is evaluated at nonzero temperatures with Fermi-Dirac statistics and a nonparabolic conduction band for bulk, narrow-gap semiconductors. This is used to study two problems of current interest: (i) inelastic scattering of single, energetic electrons by a system of plasmons, phonons, and quasiparticle excitations; and (ii) cooling of a hot, quasiequilibrium plasma by dynamically screened LO-phonon emission. Scattering of high-energy electrons injected into n-doped InAs at room temperature is analyzed and compared to the case where nonparabolicity is neglected. Plasmon losses and a larger density of states are shown to be more important for electrons in a nonparabolic conduction band with energy above the Fermi level. The energy-loss rate of a hot-electron-donor ion plasma to a cold lattice via screened LO-phonon emission in parabolic and nonparabolic bands is also obtained. It is found that even though dynamic screening of LO phonons is stronger in a nonparabolic band, the cooling rate of hot electrons in InAs can be significantly faster because of the increased density of conduction-band states. [S0163-1829(98)04916-9]. C1 Max Born Inst Nichtlineare Opt & Kurzzeitspektros, D-12489 Berlin, Germany. USAF, Res Labs, PL LIDD, Albuquerque, NM 87117 USA. RP Hasselbeck, MP (reprint author), Max Born Inst Nichtlineare Opt & Kurzzeitspektros, D-12489 Berlin, Germany. NR 37 TC 24 Z9 24 U1 1 U2 6 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 APR 15 PY 1998 VL 57 IS 16 BP 9674 EP 9681 DI 10.1103/PhysRevB.57.9674 PG 8 WC Physics, Condensed Matter SC Physics GA ZJ381 UT WOS:000073209000046 ER PT J AU Marsh, JS Watts, D Gordon, JE Anderson, C Smith, DL AF Marsh, JS Watts, D Gordon, JE Anderson, C Smith, DL TI Distortion compensation and elimination in holographic reconstruction SO APPLIED OPTICS LA English DT Article AB We discuss the quantitative location of objects from holographic images when the reconstruction wavelength differs from the recording wavelength. The holographic image equations are interpreted in a way that clarifies the meaning of stereo pairs of holographic images and indicates how backprojection methods can be used in holography to locate objects. Alternative methods involving the production of distortion free ee regions in the holographic image field during reconstruction, the use of self-calibrating objects in the object field during recording, and triangulation can be used to locate objects. (C) 1998 Optical Society of America. C1 Univ W Florida, Dept Phys, Pensacola, FL 32514 USA. USAF, Res Lab, Eglin AFB, FL 32542 USA. Univ Florida, Grad Engn & Res Ctr, Shalimar, FL 32579 USA. KBM Enterprises Inc, Niceville, FL 32578 USA. RP Marsh, JS (reprint author), Univ W Florida, Dept Phys, Pensacola, FL 32514 USA. NR 16 TC 0 Z9 0 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD APR 10 PY 1998 VL 37 IS 11 BP 2087 EP 2093 DI 10.1364/AO.37.002087 PG 7 WC Optics SC Optics GA ZG506 UT WOS:000073010500012 PM 18273130 ER PT J AU Sun, YQ Dimiduk, DM AF Sun, YQ Dimiduk, DM TI The onset of plasticity of NiAl single crystals: Changes in the electrical resistance SO SCRIPTA MATERIALIA LA English DT Article C1 Univ Illinois, Dept Mat Sci & Engn, Urbana, IL 61801 USA. USAF, Mat & Mfg Directorate, Wright Patterson AFB, OH 45433 USA. RP Sun, YQ (reprint author), Univ Illinois, Dept Mat Sci & Engn, 1304 W Green St, Urbana, IL 61801 USA. NR 9 TC 0 Z9 0 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6462 J9 SCRIPTA MATER JI Scr. Mater. PD APR 3 PY 1998 VL 38 IS 9 BP 1455 EP 1461 DI 10.1016/S1359-6462(98)00043-8 PG 7 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA ZJ947 UT WOS:000073269700021 ER PT J AU Eastwood, D Zickafoose, M Martin, JB Perry, DL Burggraf, LW AF Eastwood, D Zickafoose, M Martin, JB Perry, DL Burggraf, LW TI Vibrational and luminescence studies of weathered uranium oxides. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 USAF, Inst Technol, Wright Patterson AFB, OH 45433 USA. Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, GT Seaborg Inst Transactinium Sci, Lawrence Livermore Natl Lab, Berkeley, CA 94720 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 2 PY 1998 VL 215 MA 367-INOR BP U806 EP U806 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA ZA911 UT WOS:000072414402594 ER PT J AU Feld, WA Lorge, EA Schaaf, GM Paulvannan, K Cheek, ML Reinhardt, BA AF Feld, WA Lorge, EA Schaaf, GM Paulvannan, K Cheek, ML Reinhardt, BA TI An efficient synthesis of 5,8-dioxo-5,8-dihydroindeno[2,1-c]fluorene and derivatives. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Wright State Univ, Dept Chem, Dayton, OH 45435 USA. USAF, Polymer Branch, Mat Directorate, Res Lab, Wright Patterson AFB, OH 45433 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 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 2 PY 1998 VL 215 MA 316-ORGN BP U93 EP U93 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA ZA912 UT WOS:000072414500317 ER PT J AU Haddad, TS Oviatt, HW Schwab, JJ Mather, PT Chaffee, KP Lichtenhan, JD AF Haddad, TS Oviatt, HW Schwab, JJ Mather, PT Chaffee, KP Lichtenhan, JD TI Polydimethylsiloxanes modified with polyhedral oligomeric silsesquioxanes: From viscous oils to thermoplastics. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 USAF, Res Lab, Hughes STX Corp, Edwards AFB, CA 93524 USA. USAF, Res Lab, Wright Patterson AFB, OH 45433 USA. NR 0 TC 0 Z9 0 U1 1 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 2 PY 1998 VL 215 MA 258-POLY BP U421 EP U421 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA ZA912 UT WOS:000072414501369 ER PT J AU Humphrey, CJ Wilkes, JS AF Humphrey, CJ Wilkes, JS TI Dissolution and extraction of polymers with a room temperature molten salt. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 USAF Acad, Dept Chem, Colorado Springs, CO 80840 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 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 2 PY 1998 VL 215 MA 332-CHED BP U258 EP U258 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA ZA911 UT WOS:000072414400845 ER PT J AU Kumudinie, C Premachandra, JK Mark, JE Unroe, MR Arnold, FE AF Kumudinie, C Premachandra, JK Mark, JE Unroe, MR Arnold, FE TI Preparation and properties of rubber-toughened high temperature poly(arylene ether). SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Cincinnati, Dept Chem, Cincinnati, OH 45221 USA. Univ Cincinnati, Polymer Res Ctr, Cincinnati, OH 45221 USA. USAF, Res Lab, Polymer Branch, Dayton, OH 45433 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 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 2 PY 1998 VL 215 MA 390-POLY BP U456 EP U456 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA ZA912 UT WOS:000072414501501 ER PT J AU Lichtenhan, JD Haddad, TS Schwab, JJ Carr, MJ Chaffee, KP Mather, PT AF Lichtenhan, JD Haddad, TS Schwab, JJ Carr, MJ Chaffee, KP Mather, PT TI The next generation of silicon-based plastics: Polyhedral oligomeric silsesquioxane (POSS) nanocomposites SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 USAF, Res Lab, Edwards AFB, CA 93524 USA. Hughes STX, Edwards AFB, CA 93524 USA. NR 0 TC 2 Z9 2 U1 2 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 2 PY 1998 VL 215 MA 218-POLY BP U410 EP U410 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA ZA912 UT WOS:000072414501329 ER PT J AU Morris, RA Arnold, ST Viggiano, AA AF Morris, RA Arnold, ST Viggiano, AA TI Reactivity of atmospheric ions with hydrocarbon fuel constituents. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 USAF, Res Lab, Space Vehicles Directorate, Hanscom AFB, MA 01731 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 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 2 PY 1998 VL 215 MA 381-PHYS BP U262 EP U262 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA ZA912 UT WOS:000072414500857 ER PT J AU Patnaik, SS Pachter, R AF Patnaik, SS Pachter, R TI Modeling and simulations of anchoring characteristics in a polymer dispersed liquid crystal. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 USAF, Mat & Mfg Directorate, Res Lab, MLPJ, Wright Patterson AFB, OH 45433 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 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 2 PY 1998 VL 215 MA 187-PMSE BP U338 EP U338 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA ZA912 UT WOS:000072414501084 ER PT J AU Rolph, AC Khalili, K Hicks, BW AF Rolph, AC Khalili, K Hicks, BW TI Engineering a plasmid encoding for the green fluorescent protein under the direction of the myelin basic protein promoter and its expression in primary tissue culture SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 USAF Acad, Dept Chem, Colorado Springs, CO 80840 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 2 PY 1998 VL 215 MA 393-CHED BP U290 EP U291 PN 1 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA ZA911 UT WOS:000072414400907 ER PT J AU Sankaran, B Burkett, JL Reinhardt, BA Tan, LS AF Sankaran, B Burkett, JL Reinhardt, BA Tan, LS TI Absorption, emission and redox properties of bithienylnaphthalene systems SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Universal Technol Corp, Dayton, OH 45432 USA. Univ Dayton, Res Inst, Dayton, OH 45469 USA. USAF, Polymer Branch, Mat & Mfg Technol Directorate, AFRL MLBP,Res Lab, Wright Patterson AFB, OH 45433 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 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 2 PY 1998 VL 215 MA 284-POLY BP U428 EP U428 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA ZA912 UT WOS:000072414501395 ER PT J AU Shepherd, D Heyse, EC McGowin, A Coulliette, DL AF Shepherd, D Heyse, EC McGowin, A Coulliette, DL TI Describing sorption mass transfer by diffusion into a composite particle. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Wright State Univ, Dept Chem, Dayton, OH 45435 USA. USAF, Inst Technol, Dept Engn & Environm Management, Wright Patterson AFB, OH 45433 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 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 2 PY 1998 VL 215 MA 045-ENVR BP U581 EP U581 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA ZA911 UT WOS:000072414401862 ER PT J AU Thompson, EY Unangst, ET Strawser, LD AF Thompson, EY Unangst, ET Strawser, LD TI Total lipid analysis of the field and the laboratory-fed meadow vole (Microtus pennsylvanicus). SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 USAF Acad, Dept Chem, Colorado Springs, CO 80840 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 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 2 PY 1998 VL 215 MA 395-CHED BP U291 EP U291 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA ZA911 UT WOS:000072414400909 ER PT J AU Trohalaki, S Pachter, R AF Trohalaki, S Pachter, R TI Property prediction of non-toxic icing inhibitors. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 USAF, Wright Lab, Mat Directorate, MLPJ,WL, Wright Patterson AFB, OH 45433 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 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 2 PY 1998 VL 215 MA 146-COMP BP U545 EP U545 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA ZA911 UT WOS:000072414401738 ER PT J AU Wang, CS Price, GE Le, JW Dean, DR AF Wang, CS Price, GE Le, JW Dean, DR TI Morphology of poly(p-phenylene benzobisthiazole) (PBZT) fiber prepared via solution phase transformation. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 Univ Dayton, Res Inst, Dayton, OH 45469 USA. Syscom Technol Inc, Hilliard, OH 43026 USA. USAF, Mat Directorate, Res Lab, Wright Patterson AFB, OH 45433 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 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD APR 2 PY 1998 VL 215 MA 117-POLY BP U382 EP U382 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA ZA912 UT WOS:000072414501228 ER PT J AU Rastogi, N Soni, SR Nagar, A AF Rastogi, N Soni, SR Nagar, A TI Thermal stresses in aluminum-to-composite double-lap bonded joints SO ADVANCES IN ENGINEERING SOFTWARE LA English DT Article; Proceedings Paper CT 4th National Symposium on Large-Scale Analysis and Design on High-Performance Computers and Workstations CY OCT 15-17, 1997 CL WILLIAMSBURG, VIRGINIA AB Thermal stresses in aluminum-to-composite, symmetric, double-lap joints are studied using a three-dimensional variational, finite element analysis technique. The joint configuration considers aluminum adherend in combination with four different unidirectional laminated composite adherends subjected to uniform temperature loading. When the free expansion of the joint was permitted the aluminum plate had much higher magnitude of the thermal stresses for the cases when the upper adherends were either boron/epoxy or graphite/epoxy composite laminates as compared to the cases when the upper adherends were either glass/epoxy or the GLARE laminates. When the joint was restrained against its free expansion in the inplane coordinate directions the magnitudes of the inplane stress components in the lower aluminum adherend and the upper boron/epoxy adherend increased many fold. In this case both the joint corners were found to be critical regions for debonding initiation. (C) 1998 Elsevier Science Limited. All rights reserved. C1 AdTech Syst Res Inc, Beavercreek, OH 45432 USA. USAF, Wright Lab, FIBE, Wright Patterson AFB, OH 45433 USA. RP Rastogi, N (reprint author), AdTech Syst Res Inc, 1342 N Fairfield Rd, Beavercreek, OH 45432 USA. NR 3 TC 23 Z9 23 U1 0 U2 2 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0965-9978 J9 ADV ENG SOFTW JI Adv. Eng. Softw. PD APR-JUL PY 1998 VL 29 IS 3-6 BP 273 EP 281 DI 10.1016/S0965-9978(97)00079-3 PG 9 WC Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering; Engineering, Multidisciplinary SC Computer Science; Engineering GA 112LN UT WOS:000075496300011 ER PT J AU Grismer, MJ Strang, WZ Tomaro, RF Witzeman, FC AF Grismer, MJ Strang, WZ Tomaro, RF Witzeman, FC TI Cobalt: A parallel, implicit, unstructured Euler/Navier-Stokes solver SO ADVANCES IN ENGINEERING SOFTWARE LA English DT Article; Proceedings Paper CT 4th National Symposium on Large-Scale Analysis and Design on High-Performance Computers and Workstations CY OCT 15-17, 1997 CL WILLIAMSBURG, VA AB A parallel, implicit, unstructured Euler/Navier-Stokes solver has been developed that is accurate, robust and user-friendly. The parallel performance of the code is excellent, showing linear, and at times better than linear, scalability on current parallel architectures. This, combined with the time savings afforded by the implicit algorithm, permits the routine analysis of large viscous problems on workstation-class processors. Published by Elsevier Science Limited. C1 Wright Lab, CRD Res Branch, Interdisciplinary & Appl CFD Sect, Wright Patterson AFB, OH 45433 USA. RP Wright Lab, CRD Res Branch, Interdisciplinary & Appl CFD Sect, Wright Patterson AFB, OH 45433 USA. NR 17 TC 38 Z9 38 U1 0 U2 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0965-9978 EI 1873-5339 J9 ADV ENG SOFTW JI Adv. Eng. Softw. PD APR-JUL PY 1998 VL 29 IS 3-6 BP 365 EP 373 DI 10.1016/S0965-9978(97)00075-6 PG 9 WC Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering; Engineering, Multidisciplinary SC Computer Science; Engineering GA 112LN UT WOS:000075496300023 ER PT J AU Horwitz, JR Chwals, WJ Doski, JJ Suescun, EA Cheu, HW Lally, KP AF Horwitz, JR Chwals, WJ Doski, JJ Suescun, EA Cheu, HW Lally, KP TI Pediatric wound infections - A prospective multicenter study SO ANNALS OF SURGERY LA English DT Article ID ANTIBIOTIC-PROPHYLAXIS; SITE INFECTIONS; RATES; SURVEILLANCE; SURGERY; EPIDEMIOLOGY; INFANTS; RISK AB Objective Surgical wound infections remain a significant source of postoperative morbidity. This study was undertaken to determine prospectively the incidence of postoperative wound infections in children in a multi-institutional fashion and to identify the risk factors associated with the development of a wound infection in this population. Summary Background Data Despite a large body of literature in adults, there have been only two reports from North America concerning postoperative wound infections in children. Methods All infants and children undergoing operation on the pediatric surgical services of three institutions during a 17-month period were prospectively followed for 30 days after surgery for the development of a wound infection. Results A total of 846 of 1021 patients were followed for 30 days. The overall incidence of wound infection was 4.4%. Factors found to be significantly associated with a postoperative wound infection were the amount of contamination at operation (p = 0.006) and the duration of the operation (p = 0.03). Comparing children who developed a wound infection with those who did not, there were no significant differences in age, sex, American Society of Anesthesiologists (ASA) preoperative assessment score, length of preoperative hospitalization, location of operation (intensive care unit vs, operating room), presence of a coexisting disease or remote infection, or the use of perioperative antibiotics. Conclusions Our results suggest that wound infections in children are related more to the factors at operation than to the overall physiologic status. Procedures can be performed in the intensive care unit without any increase in the incidence of wound infection. C1 Univ Texas, Sch Med, Houston, TX USA. Hermann Childrens Hosp, Houston, TX USA. Wilford Hall USAF Med Ctr, San Antonio, TX 78236 USA. Bowman Gray Sch Med, Winston Salem, NC USA. RP Lally, KP (reprint author), Div Pediat Surg, 6431 Fannin,Suite 5-258, Houston, TX 77030 USA. NR 29 TC 36 Z9 37 U1 0 U2 1 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 USA SN 0003-4932 J9 ANN SURG JI Ann. Surg. PD APR PY 1998 VL 227 IS 4 BP 553 EP 558 DI 10.1097/00000658-199804000-00017 PG 6 WC Surgery SC Surgery GA ZG507 UT WOS:000073010600017 PM 9563545 ER PT J AU Magnuson, JK Stern, RV Gossett, JM Zinder, SH Burris, DR AF Magnuson, JK Stern, RV Gossett, JM Zinder, SH Burris, DR TI Reductive dechlorination of tetrachloroethene to ethene by two-component enzyme pathway SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Article ID DEHALOSPIRILLUM MULTIVORANS; METHANOGENIC CONDITIONS; DESULFOMONILE-TIEDJEI; ENRICHMENT CULTURE; VINYL-CHLORIDE; TRICHLOROETHYLENE; DEHALOGENASE; TRANSFORMATIONS; PURIFICATION; GROUNDWATER AB Two membrane-bound, reductive dehalogenases that constitute a novel pathway for complete dechlorination of tetrachloroethene (perchloroethylene [PCE]) to ethene were partially purified from an anaerobic microbial enrichment culture containing Dehalococcoides ethenogenes 195. When titanium(III) citrate and methyl viologen were used as reductants, PCE-reductive dehalogenase (PCE-RDase) (51-kDa) dechlorinated PCE to trichloroethene (TCE) at a rate of 20 mu mol/min/mg of protein. TCE-reductive dehalogenase (TCE-RDase) (61 kDa) dechlorinated TCE to ethene. TCE, cis-1,2-dichloroethene, and 1,1-dichloroethene were dechlorinated at similar rates, 8 to 12 mu mol/min/mg of protein. Vinyl chloride and trans-1,2-dichloroethene were degraded at rates which were approximately 2 orders of magnitude lower. The light-reversible inhibition of TCE-RDase by iodopropane and the light-reversible inhibition of PCE-RDase by iodoethane suggest that both of these dehalogenases contain Co(I) corrinoid cofactors. Isolation and characterization of these novel bacterial enzymes provided further insight into the catalytic mechanisms of biological reductive dehalogenation. C1 USAF, Armstrong Lab, Environ Directorate, Tyndall AFB, FL 32403 USA. Cornell Univ, Sch Civil & Environm Engn, Ithaca, NY 14853 USA. Cornell Univ, Microbiol Sect, Ithaca, NY 14853 USA. RP USA, ERDEC, SCBRD RTL, Bldg E3150, Aberdeen Proving Ground, MD 21010 USA. EM jkmagnus@c-mail.apgea.army.mil NR 37 TC 169 Z9 177 U1 6 U2 46 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1752 N ST NW, WASHINGTON, DC 20036-2904 USA SN 0099-2240 EI 1098-5336 J9 APPL ENVIRON MICROB JI Appl. Environ. Microbiol. PD APR PY 1998 VL 64 IS 4 BP 1270 EP 1275 PG 6 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA ZF412 UT WOS:000072894900016 PM 10671186 ER PT J AU Andersen, G Knize, RJ AF Andersen, G Knize, RJ TI Holographically corrected microscope with a large working distance SO APPLIED OPTICS LA English DT Article AB We present a design for a microscope with a simple objective lens with a high numerical aperture. The large amounts of aberrations present in the system are removed when a point-source image hologram is recorded. The resultant instrument has a large working distance (>0.17 m) and a moderate field of view over a limited bandwidth. We demonstrate the application of this device to imaging submicrometer details inside a vacuum. C1 USAF Acad, Dept Phys, Laser & Opt Res Ctr, Colorado Springs, CO 80840 USA. RP Andersen, G (reprint author), USAF Acad, Dept Phys, Laser & Opt Res Ctr, Suite 2A6,2354 Fairchild Dr, Colorado Springs, CO 80840 USA. NR 12 TC 7 Z9 8 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD APR 1 PY 1998 VL 37 IS 10 BP 1849 EP 1853 DI 10.1364/AO.37.001849 PG 5 WC Optics SC Optics GA ZD695 UT WOS:000072713700021 PM 18273098 ER PT J AU Patterson, BM White, WR Robbins, TA Knize, RJ AF Patterson, BM White, WR Robbins, TA Knize, RJ TI Linear optical effects in Z-scan measurements of thin films SO APPLIED OPTICS LA English DT Article ID SINGLE-BEAM; GLASS AB We show that it is possible, in Z-scan measurements of thin films, to obtain data that closely resemble typical results for nonlinear optical materials, but which actually arise from linear optical effects caused by sample damage. Z-scan measurements on a silica-based thin film yielded the expected peak-valley signature of Z-scan data, but subsequent analysis and microscopic examination of the film indicated that the data resulted from an ablation hole produced in the film when it was near the laser focus. The resulting spatial variation of the linear refractive index of the film produced a lensing effect that mimicked the typical Z-scan response. Scalar diffraction theory was used to model the effects of a spatially varying refractive index and gave results that qualitatively agreed with the Z-scan measurements. (C) 1998 Optical Society of America. C1 USAF Acad, Dept Phys, Laser & Opt Res Ctr, Colorado Springs, CO 80840 USA. RP Patterson, BM (reprint author), USAF Acad, Dept Phys, Laser & Opt Res Ctr, Colorado Springs, CO 80840 USA. NR 9 TC 21 Z9 21 U1 0 U2 1 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD APR 1 PY 1998 VL 37 IS 10 BP 1854 EP 1857 DI 10.1364/AO.37.001854 PG 4 WC Optics SC Optics GA ZD695 UT WOS:000072713700022 PM 18273099 ER PT J AU Johnson, RO Karis, SJ Perram, GP Roh, WB AF Johnson, RO Karis, SJ Perram, GP Roh, WB TI Characterization of a Br(P-2(1/2))-CO2(10(0)1-10(0)0) transfer laser driven by photolysis of iodine monobromide SO APPLIED PHYSICS B-LASERS AND OPTICS LA English DT Article ID VIBRATIONAL ENERGY-TRANSFER; CO2; SPECTROSCOPY; RELAXATION; HCN AB A CO2 laser operating on the 10(0)1-10(0)0 transition at lambda = 4.3 mu m and pumped by E-V energy transfer from Br(P-2(1/2)) has been demonstrated. The dynamics and performance of this device were characterized by observing the time-resolved stimulated emission and the steady-state spontaneous side fluorescence after photolysis of IBr or Br-2 by a frequency-doubled Nd:YAG laser or Ar+ laser, respectively. Although the E-V excitation kinetics are favorable, rapid vibrational relaxation limits laser action to CO2 pressures of less than 1 Torr. Numerical modeling of laser pulse shapes and the dependence on IBr and CO2 pressure and photolysis energy establish a relatively high gain of 0.33%/cm, a CO2-pressure-dependent optical loss of 0.04-0.06%/cm, and an efficiency of 2 x 10(-5) 4.3-mu m-laser photons per incident photolysis photon. The CO2 fluorescence after photolysis of a fixed Br-2/CO2 gas mixture decreases as a function of photolysis time by about 30%/h, indicating the photolytic production of an important quencher. C1 USAF, Inst Technol, Dept Engn Phys, Wright Patterson AFB, OH 45433 USA. RP Johnson, RO (reprint author), Sci Applicat Int Corp, 3701 N Fairfax Dr,Suite 1001, Arlington, VA 22203 USA. OI Perram, Glen/0000-0002-4417-3929 NR 24 TC 1 Z9 1 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0946-2171 J9 APPL PHYS B-LASERS O JI Appl. Phys. B-Lasers Opt. PD APR PY 1998 VL 66 IS 4 BP 411 EP 415 DI 10.1007/s003400050411 PG 5 WC Optics; Physics, Applied SC Optics; Physics GA ZH506 UT WOS:000073117900004 ER PT J AU Schissel, DJ Sartori, C AF Schissel, DJ Sartori, C TI An unusual papule - Accessory tragus SO ARCHIVES OF DERMATOLOGY LA English DT Article C1 Wilford Hall USAF Med Ctr, Lackland AFB, TX 78236 USA. RP Schissel, DJ (reprint author), Wilford Hall USAF Med Ctr, Lackland AFB, TX 78236 USA. NR 6 TC 1 Z9 1 U1 0 U2 0 PU AMER MEDICAL ASSOC PI CHICAGO PA 515 N STATE ST, CHICAGO, IL 60610 USA SN 0003-987X J9 ARCH DERMATOL JI Arch. Dermatol. PD APR PY 1998 VL 134 IS 4 BP 500 EP + PG 4 WC Dermatology SC Dermatology GA ZG877 UT WOS:000073049000017 PM 9554306 ER PT J AU Webb, JT Pilmanis, AA O'Connor, RB AF Webb, JT Pilmanis, AA O'Connor, RB TI An abrupt zero-preoxygenation altitude threshold for decompression sickness symptoms SO AVIATION SPACE AND ENVIRONMENTAL MEDICINE LA English DT Article ID 100-PERCENT OXYGEN AB Introduction: The altitude threshold for decompression sickness (DCS) symptoms has been variously described as being 18,000 ft (5,487 m) to above 25,000 ft (7,620 m). Safety and efficiency of aerospace operations require more precise determination of the DCS threshold. Methods: Subjects were 124 males who were exposed to simulated altitudes (11 at 11,500 ft; 10 at 15,000 ft; 8 at 16,500 ft; 10 at 18,100 ft; 10 at 19,800 ft; 20 at 21,200 ft; 20 at 22,500 ft; 10 at 23,800 ft, and 25 al 25,000 ft) for 4 to 8 h. All breathed 100% oxygen beginning with ascent. Subjects were monitored for precordial venous gas emboli (VCE) and DCS symptoms. Probit curves representing altitude vs. incidence of DCS symptoms and VGE allowed estimation of respective risk. Results: VGE were first observed al 15,000 ft with increasing incidence at higher altitudes; over 50% at 21,200 ft and 70% or higher at 22,500 ft and above. The lowest altitude occurrence of DCS was a 5% incidence at 21,200 ft. At 22,500 fi, the DCS incidence abruptly climbed to 55%. Conclusion: A 5% threshold for DCS symptoms was concluded to be 20,500 ft under the conditions of this study. The abrupt increase in DCS symptoms with zero-preoxygenation exposure above 21,200 ft implies a need for reconsideration of current USAF and FAA altitude exposure guidance. C1 KRUG Life Sci Inc, San Antonio, TX 78232 USA. USAF, Res Lab, Flight Stress Protect Div, Brooks AFB, TX 78235 USA. RP Webb, JT (reprint author), KRUG Life Sci Inc, 13818 Chittim Oak, San Antonio, TX 78232 USA. NR 24 TC 31 Z9 31 U1 0 U2 0 PU AEROSPACE MEDICAL ASSOC PI ALEXANDRIA PA 320 S HENRY ST, ALEXANDRIA, VA 22314-3579 USA SN 0095-6562 J9 AVIAT SPACE ENVIR MD JI Aviat. Space Environ. Med. PD APR PY 1998 VL 69 IS 4 BP 335 EP 340 PG 6 WC Public, Environmental & Occupational Health; Medicine, General & Internal; Sport Sciences SC Public, Environmental & Occupational Health; General & Internal Medicine; Sport Sciences GA ZF402 UT WOS:000072893900001 PM 9561279 ER PT J AU Dart, TS Butler, W AF Dart, TS Butler, W TI Towards new paradigms for the treatment of hypobaric decompression sickness SO AVIATION SPACE AND ENVIRONMENTAL MEDICINE LA English DT Article AB Altitude induced (hypobaric) decompression sickness (DCS) has long been treated with ground level oxygen and U.S. Navy Treatment Tables 5 and 6. These treatment tables originate from surface excursion diving and, when implemented, require significant resource allocation. Although they are effective treatment regimens, these tables were not developed for treating hypobaric DCS which has an etiology similar to saturation diving DCS. In this review, different treatment options for hypobaric DCS are presented. These options include more aggressive use of ground level oxygen and treatment tables using a maximum pressure of 2 atmospheres (ATA). Specific attention is given to USAF Table VIII, an experimental hypobaric DCS treatment table, and space suit overpressurization treatment. This paradigm shift for DCS treatment is based on a projected increase in hypobaric DCS treatment From exposure to low pressure during several operational conditions: cruise flight in the next generation aircraft (e.g., F-22); high altitude, unpressurized flight by special operations forces; and the extraordinary amount of extravehicular activity (EVA) required to construct the international space station. Anticipating the need to treat DCS encountered during these and other activities, it is proposed that 2 ATA or less hyperbaric oxygen (HBO) treatment conjoined with new collapsible chamber technology can be used to address these issues in a safe and cost effective fashion. C1 Armstrong Lab, Davis Hyperbar Lab, Hyperbar Operat & Dev, Brooks AFB, TX 78235 USA. RP Dart, TS (reprint author), Armstrong Lab, Davis Hyperbar Lab, Hyperbar Operat & Dev, AL-AOH,2509 Kennedy Circle,Suite 309, Brooks AFB, TX 78235 USA. NR 38 TC 13 Z9 15 U1 0 U2 1 PU AEROSPACE MEDICAL ASSOC PI ALEXANDRIA PA 320 S HENRY ST, ALEXANDRIA, VA 22314-3579 USA SN 0095-6562 J9 AVIAT SPACE ENVIR MD JI Aviat. Space Environ. Med. PD APR PY 1998 VL 69 IS 4 BP 403 EP 409 PG 7 WC Public, Environmental & Occupational Health; Medicine, General & Internal; Sport Sciences SC Public, Environmental & Occupational Health; General & Internal Medicine; Sport Sciences GA ZF402 UT WOS:000072893900011 PM 9561289 ER PT J AU Cohen, D AF Cohen, D TI An objective measure of seat comfort SO AVIATION SPACE AND ENVIRONMENTAL MEDICINE LA English DT Article AB Uncomfortable aircrew seating is more than just a nuisance, it has the potential to produce a cumulative trauma which can significantly affect attention, information processing, and task performance to the extent of interfering with mission completion or contributing to mishaps. Yet, for decades uncomfortable seating has endured as an aircrew complaint with little progress made toward resolving it. Aircraft design techniques have steadily progressed, but the method for ascertaining seating pressure issues has remained, unfortunately, the same: simply ask aircrew where it hurts and hope some cushion changes work. Currently, there exist sensor technologies which potentially can economically and effectively address this problem by reducing the comfort analysis to the examination of an objective, quantitative pressure map. This technical note discusses the brief history of seat pressure measurement research, enumerates some of the technologies that are available that can be applied to the problem, and finally, describes a seated pressure measurement demonstration which shows the power of the approach for maximizing comfort. C1 USAF, Flight Test Ctr, Human Syst Integrat Flight, Edwards AFB, CA USA. RP Cohen, D (reprint author), Armstrong Lab AL XPTM, Crew Syst, 2509 Kennedy Circle, Brooks AFB, TX 78235 USA. NR 17 TC 9 Z9 9 U1 0 U2 5 PU AEROSPACE MEDICAL ASSOC PI ALEXANDRIA PA 320 S HENRY ST, ALEXANDRIA, VA 22314-3579 USA SN 0095-6562 J9 AVIAT SPACE ENVIR MD JI Aviat. Space Environ. Med. PD APR PY 1998 VL 69 IS 4 BP 410 EP 414 PG 5 WC Public, Environmental & Occupational Health; Medicine, General & Internal; Sport Sciences SC Public, Environmental & Occupational Health; General & Internal Medicine; Sport Sciences GA ZF402 UT WOS:000072893900012 PM 9561290 ER PT J AU Convertino, VA Ludwig, DA Gray, BD Vernikos, J AF Convertino, VA Ludwig, DA Gray, BD Vernikos, J TI Effects of exposure to simulated microgravity on neuronal catecholamine release and blood pressure responses to norepinephrine and angiotensin SO CLINICAL AUTONOMIC RESEARCH LA English DT Article DE autonomic function; cold pressor test; vasoconstriction ID SPACEFLIGHT; PLASMA; HUMANS AB We tested the hypothesis that exposure to microgravity reduces the neuronal release of catecholamines and blood pressure responses to norepinephrine and angiotensin. Eight men underwent 30 days of 6 degrees head-down tilt (HDT) bedrest to simulate exposure to microgravity. Plasma norepinephrine and mean arterial blood pressure (MAP) were measured before and after a cold pressor test (CPT) and graded norepinephrine infusion (8, 16 and 32 ng/kg/min) on day 6 of a baseline control period (C6) and on days 14 and 27 of HDT. MAP and plasma angiotensin II (Ang-II) were measured during graded Ang-II infusion (1, 2 and 4 ng/kg/min) on C8 and days 16 and 29 of HDT. Baseline total circulating norepinephrine was reduced from 1017 ng during the baseline control period to 610 ng at day 14 and 673 ng at day 27 of HDT, confirming a hypoadrenergic state. An elevation of norepinephrine (+178 ng) to the CPT during the baseline control period was eliminated by HDT days 14 and 27. During norepinephrine infusion, similar elevations in plasma norepinephrine (7.7 pg/ml/ng/kg/min) caused similar elevations in MAP (0.12 mmHg/ng/kg/min) across all test days. Ang-II infusion produced higher levels of plasma Ang-II during HDT (47.3 pg/ml) than during baseline control (35.5 pg/ml), while producing similar corresponding elevations in blood pressure. While vascular responsiveness to norepinephrine appears unaffected, impaired neuronal release of norepinephrine and reduced vascular responsiveness to Ang-II might contribute to the lessened capacity to vasoconstrict after spaceflight. The time course of alterations indicates effects that occur within two weeks of exposure. (C) 1998 Lippincott-Raven Publishers. C1 USAF, Res Lab, Flight Mot Effects Branch, Flight Stress Ptotect Div, Brooks AFB, TX USA. Univ N Carolina, Dept Math Sci, Greensborough, NC USA. NASA, Washington, DC 20546 USA. RP Convertino, VA (reprint author), AFRL, HEPM, Physiol Res Branch, Clin Sci Sect, 2504 Gillingham Dr, Brooks AFB, TX 78235 USA. NR 28 TC 16 Z9 16 U1 0 U2 4 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 USA SN 0959-9851 J9 CLIN AUTON RES JI Clin. Auton. Res. PD APR PY 1998 VL 8 IS 2 BP 101 EP 110 DI 10.1007/BF02267820 PG 10 WC Clinical Neurology; Neurosciences SC Neurosciences & Neurology GA ZQ343 UT WOS:000073849800004 PM 9613800 ER PT J AU Oran, ES Weber, JW Stefaniw, EI Lefebvre, MH Anderson, JD AF Oran, ES Weber, JW Stefaniw, EI Lefebvre, MH Anderson, JD TI A numerical study of a two-dimensional H-2-O-2-Ar detonation using a detailed chemical reaction model SO COMBUSTION AND FLAME LA English DT Article ID SIMULATIONS; WAVES AB Two-dimensional computations of the propagation of a detonation in a low-pressure, argon-diluted mixture of hydrogen and oxygen were performed using a detailed chemical reaction mechanism. Cellular structure developed after an initial perturbation was applied to a one-dimensional solution placed on a two-dimensional grid. The energy-release pattern in a detonation cell showed that, in addition to the primary release of energy behind the Mach stem, there is a secondary energy release that starts about two-thirds of the way through the cell. Reignition, which occurs as transverse waves collide, results in an explosion that spreads over a region and releases a considerable amount of energy. Resolution tests showed convergence of the detonation mode (number of triple points or transverse waves) reached at the end of the computations, as well as global and local energy release. The computations were performed on massively parallel Connection Machines for which new approaches were developed to maximize the speed and efficiency of integrations. (C) 1998 by The Combustion Institute. C1 USN, Res Lab, Computat Phys & Fluid Dynam Lab, Washington, DC 20375 USA. USAF, Wright Lab, Propuls Syst Branch, Wright Patterson AFB, OH 45433 USA. Berkeley Res Associates, Springfield, VA 22151 USA. Royal Mil Acad, Dept Chem, B-1040 Brussels, Belgium. Univ Maryland, Dept Aerosp Engn, College Pk, MD 20742 USA. RP Oran, ES (reprint author), USN, Res Lab, Computat Phys & Fluid Dynam Lab, Code 6404, Washington, DC 20375 USA. NR 40 TC 120 Z9 136 U1 6 U2 20 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 0010-2180 J9 COMBUST FLAME JI Combust. Flame PD APR PY 1998 VL 113 IS 1-2 BP 147 EP 163 DI 10.1016/S0010-2180(97)00218-6 PG 17 WC Thermodynamics; Energy & Fuels; Engineering, Multidisciplinary; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA YW128 UT WOS:000071900700012 ER PT J AU Sarkar, TK Nagaraja, S Wicks, MC AF Sarkar, TK Nagaraja, S Wicks, MC TI A deterministic direct data domain approach to signal estimation utilizing nonuniform and uniform 2-D arrays SO DIGITAL SIGNAL PROCESSING LA English DT Article AB A direct data domain deterministic approach utilizing a nonuniform array to adaptively estimate the signal strength of an incoming signal in the presence of strong jammers, clutter, and thermal noise is presented. This method is based on choosing a weighted difference of neighboring antenna outputs, based on the direction of arrival of the signal of interest, in such a way that only the unwanted components remain. These unwanted signals are then nulled by adaptive weights. These weights are then used to estimate the signal strength for a set of sampling time instants. This approach is suited for a highly changing environment, particularly in the presence of blinking jammers and where clutter characteristics change rapidly, provided the signal of interest does not change significantly during the observation interval. Two main deterministic approaches are presented-one based on the solution of a generalized eigenvalue problem, the other based on the solution of a set of linear equations utilizing the conjugate gradient method. These methods are applied to nonuniform as well as uniform 2D arrays, and the results are compared. (C) 1998 Academic Press. C1 Syracuse Univ, Dept Elect & Comp Engn, Syracuse, NY 13244 USA. USAF, Res Lab, Sensors Directorate, Rome, NY 13441 USA. RP Sarkar, TK (reprint author), Syracuse Univ, Dept Elect & Comp Engn, Syracuse, NY 13244 USA. NR 3 TC 13 Z9 14 U1 0 U2 1 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 1051-2004 J9 DIGIT SIGNAL PROCESS JI Digit. Signal Prog. PD APR PY 1998 VL 8 IS 2 BP 114 EP 125 DI 10.1006/dspr.1997.0308 PG 12 WC Engineering, Electrical & Electronic SC Engineering GA ZN145 UT WOS:000073614400006 ER PT J AU Baroth, E Wells, G Merrell, J AF Baroth, E Wells, G Merrell, J TI An evaluation of multiplexed analog digitizer boards - Part 1 SO EE-EVALUATION ENGINEERING LA English DT Article AB How many bits of accuracy does a 16-bit board have on a typical PC? The simple answer is: Sixteen, that's what the manu al says. But the real answer is far more complicated. C1 CALTECH, Jet Prop Lab, Measurement Technol Ctr, Pasadena, CA 91109 USA. USAF, Res Lab, Edwards AFB, CA USA. RP Baroth, E (reprint author), CALTECH, Jet Prop Lab, Measurement Technol Ctr, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU NELSON PUBLISHING PI NOKOMIS PA 2504 NORTH TAMIAMI TRAIL, NOKOMIS, FL 34275-3482 USA SN 0149-0370 J9 EE-EVAL ENG JI EE-Eval. Eng. PD APR PY 1998 VL 37 IS 4 BP 26 EP + PG 6 WC Engineering, Electrical & Electronic SC Engineering GA ZG063 UT WOS:000072961900004 ER PT J AU Johnson, WS Calcaterra, JR AF Johnson, WS Calcaterra, JR TI A fibre stress-based parameter for thermomechanical fatigue life predictions of titanium matrix composites SO FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES LA English DT Article DE titanium; metal matrix composite; thermomechanical fatigue; life prediction; elevated temperature AB Titanium Matrix Composites (TMCs) are envisioned for use in the next generation of advanced aircraft and their engines. To ensure a smooth transition to industry, fatigue life prediction methodologies, which can account for random variations in mechanical and thermal loads, must be developed. To facilitate the development of such a model, fatigue testing has been conducted at Georgia Tech. on [0/+/-45/90](s) and [90/+/-45/0](s) laminates of SCS-6/Timetal 21S. The tests were done at temperatures of 400, 500 and 650 degrees C, with hold times of 1, 10 and 100 s superimposed at the maximum stress. The purpose of the tests was to separate the effect of time-dependent deformation from the effect of environmental degradation. Using the results of these tests, and results generated at NASA-Lewis Research Center (LeRC) and the US Air Force's Wright Laboratory, a model has been developed which is based on the stress in the load-carrying fibres. The stress is modified by an effective stress concentration factor that is due to matrix cracking and a factor that includes the effect of hold times. It is a single term model that is intended for treating any variations in mechanical and thermal loads. Verification of this model is achieved by predicting fatigue lives for specimens subjected to spectrum loads performed at NASA-Lang]ey Research Center (LaRC) and vacuum tests completed at Georgia Tech. The model is compared to five methodologies previously developed for life prediction, and is shown to have significantly better predictive power while reducing the number of empirical constants and curve fitting parameters necessary to collapse the data. C1 Georgia Inst Technol, Sch Mat Sci & Engn, Atlanta, GA 30332 USA. USAF, Res Lab, VAVS, Wright Patterson AFB, OH 45433 USA. RP Johnson, WS (reprint author), Georgia Inst Technol, Sch Mat Sci & Engn, Atlanta, GA 30332 USA. NR 23 TC 2 Z9 2 U1 0 U2 3 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 8756-758X J9 FATIGUE FRACT ENG M JI Fatigue Fract. Eng. Mater. Struct. PD APR PY 1998 VL 21 IS 4 BP 479 EP 492 PG 14 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA ZP908 UT WOS:000073800700010 ER PT J AU Cotton, PB Vaughan, J Mauldin, P Nickl, N Schutz, S Libby, E Jowell, P AF Cotton, PB Vaughan, J Mauldin, P Nickl, N Schutz, S Libby, E Jowell, P TI Yield of upper endoscopy in dyspepsia; A multicenter database study SO GASTROINTESTINAL ENDOSCOPY LA English DT Meeting Abstract C1 Med Univ S Carolina, Charleston, SC USA. Univ Kentucky, Lexington, KY USA. Wilford Hall USAF Med Ctr, San Antonio, TX USA. Tufts Univ, Boston, MA USA. Durham VAMC, Durham, NC USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MOSBY-YEAR BOOK INC PI ST LOUIS PA 11830 WESTLINE INDUSTRIAL DR, ST LOUIS, MO 63146-3318 USA SN 0016-5107 J9 GASTROINTEST ENDOSC JI Gastrointest. Endosc. PD APR PY 1998 VL 47 IS 4 SU S MA 87 BP AB46 EP AB46 PG 1 WC Gastroenterology & Hepatology SC Gastroenterology & Hepatology GA ZK314 UT WOS:000073306800088 ER PT J AU Nickl, N Vaughan, J Cotton, PB Jowell, P Libby, E Schutz, S AF Nickl, N Vaughan, J Cotton, PB Jowell, P Libby, E Schutz, S TI Duration of colonoscopy: The effect of trainee presence on procedure time. SO GASTROINTESTINAL ENDOSCOPY LA English DT Meeting Abstract C1 Univ Kentucky, Lexington, KY USA. Med Univ S Carolina, Charleston, SC 29425 USA. VAMC, Durham, NH USA. Tufts New England Med Ctr, Boston, MA USA. Wilford Hall USAF Med Ctr, San Antonio, TX 78236 USA. NR 0 TC 0 Z9 0 U1 1 U2 4 PU MOSBY-YEAR BOOK INC PI ST LOUIS PA 11830 WESTLINE INDUSTRIAL DR, ST LOUIS, MO 63146-3318 USA SN 0016-5107 J9 GASTROINTEST ENDOSC JI Gastrointest. Endosc. PD APR PY 1998 VL 47 IS 4 SU S MA 129 BP AB57 EP AB57 PG 1 WC Gastroenterology & Hepatology SC Gastroenterology & Hepatology GA ZK314 UT WOS:000073306800130 ER PT J AU Dewan, EM Picard, RH O'Neil, RR Gardiner, HA Gibson, J Mill, JD Richards, E Kendra, M Gallery, WO AF Dewan, EM Picard, RH O'Neil, RR Gardiner, HA Gibson, J Mill, JD Richards, E Kendra, M Gallery, WO TI MSX satellite observations of thunderstorm-generated gravity waves in mid-wave infrared images of the upper stratosphere SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article AB Data from the Midcourse Space Experiment (MSX) has provided the first observations of thunderstorm-generated gravity waves imaged from space. Gravity wave theory predicts that isolated, sufficiently convective thunderstorms can launch waves and create a unique intensity pattern of concentric circles on a radiating surface of constant altitude above such a storm. Among the MSX constant-nadir-angle mid-wave infrared (MWIR) observations, two instances of such patterns have been identified. It was confirmed from meteorological satellite images that highly convective isolated thunderstorms occurred at the locations and times expected. C1 USAF, Res Lab, Hanscom AFB, Bedford, MA 01731 USA. ERIM Int Inc, Arlington, VA 22209 USA. Boston Coll, Newton, MA USA. Radex Inc, Bedford, MA 01730 USA. Atmospher & Environm Res Inc, Cambridge, MA 02139 USA. RP Dewan, EM (reprint author), USAF, Res Lab, Hanscom AFB, Bedford, MA 01731 USA. NR 4 TC 129 Z9 130 U1 1 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD APR 1 PY 1998 VL 25 IS 7 BP 939 EP 942 DI 10.1029/98GL00640 PG 4 WC Geosciences, Multidisciplinary SC Geology GA ZE646 UT WOS:000072815400001 ER PT J AU Loehr, J Siskaninetz, W Wiemeri, J Feld, S AF Loehr, J Siskaninetz, W Wiemeri, J Feld, S TI Optical communication systems for avionics SO IEEE AEROSPACE AND ELECTRONIC SYSTEMS MAGAZINE LA English DT Article AB Avionic information processing and transmission requirements are increasing geometrically, with no end in sight. The only feasible way to meet them is to incorporate fiber-optic communication systems into avionic platforms. Such systems can be employed to replace standard electronic components, to augment existing systems, or to enable new technologies. In this paper, we survey the field of low-power communication systems from the avionics engineering perspective, We review the fundamental merits of optical fiber for information transmission and discuss various information modulation schemes, These modulation techniques determine the performance requirements for laser transmitters. We describe the horizontal-and vertical-cavity semiconductor lasers currently available for these systems, and measure their performance against the additional environmental constraints of avionics platforms. Finally, we outline expected near-and far-term trends in system and device development. C1 USAF, Wright Lab, AADP, Avion Directorate,Heterojunct Phys Branch, Wright Patterson AFB, OH 45433 USA. Wright State Univ, Dayton, OH 45435 USA. RP Loehr, J (reprint author), USAF, Wright Lab, AADP, Avion Directorate,Heterojunct Phys Branch, Wright Patterson AFB, OH 45433 USA. NR 5 TC 2 Z9 3 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0885-8985 J9 IEEE AERO EL SYS MAG JI IEEE Aerosp. Electron. Syst. Mag. PD APR PY 1998 VL 13 IS 4 BP 9 EP 12 DI 10.1109/62.666830 PG 4 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA ZF702 UT WOS:000072923500005 ER PT J AU Cloyd, JS AF Cloyd, JS TI Status of the United States Air Force's more electric aircraft initiative SO IEEE AEROSPACE AND ELECTRONIC SYSTEMS MAGAZINE LA English DT Article AB Since the early 1990's, the United States Air Force has been successfully pursuing advancement in aircraft electrical power system technologies as a means of collectively establishing the capability to reduce dramatically or eliminate centralized hydraulics aboard aircraft and replace them with electrical power as the motive force for all aircraft functions. This overall approach (called the More Electric Aircraft, MEA) has been analytically determined to provide dramatic improvements in reliability, maintainability, supportability and operations/support cost as well as enhancements in aircraft weight, volume, and battle-damage reconfigurability. Historically, the concept of an electrically-based aircraft had been considered by military aircraft designers since World War II, but a lack of electrical power generation capability and the volume of required power conditioning equipment rendered this approach unfeasible. Advances in switched reluctance configuration electric machines and solid state power electronics have now enabled demonstration of an MEA. A time-and technology availability-phased research and development program has been structured to demonstrate the required electrical component and subsystems performance to allow equivalent or improved aircraft performance over the use of hydraulic power. Generation I of the MEA initiative, scheduled for completion in 1998, officially established electrical capabilities toward the elimination of aircraft hydraulics. Generation II of the initiative, with technology availability in 2005, projects such dramatic improvements in electrical power capability so as to provide large quantities (hundreds of kilowatts) of excess onboard electrical power for a variety of revolutionary military functions. This paper provides: 1) a brief historical treatment of technology milestones achieved which enabled the MEA approach; 2) a status of United States Air Force and Department of Defense research and development programs in electrical power generation, distribution, energy storage, systems integration and flight testing; 3) a description of some of the Air Force's planned demonstration activities in aircraft electrical power subsystems; and 4) the dual use nature of many of these technologies enabling a variety of electric and hybrid electrically-propelled military weapon systems and commercial vehicles. C1 USAF, Wright Lab, Wright Patterson AFB, OH 45433 USA. RP Cloyd, JS (reprint author), USAF, Wright Lab, 1950 5th St, Wright Patterson AFB, OH 45433 USA. NR 4 TC 28 Z9 37 U1 1 U2 6 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0885-8985 J9 IEEE AERO EL SYS MAG JI IEEE Aerosp. Electron. Syst. Mag. PD APR PY 1998 VL 13 IS 4 BP 17 EP 22 DI 10.1109/62.666832 PG 6 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA ZF702 UT WOS:000072923500007 ER PT J AU Montgomery, JB Sanderson, RB Baxley, FO AF Montgomery, JB Sanderson, RB Baxley, FO TI Two color temporally correlated infrared background measurements SO IEEE AEROSPACE AND ELECTRONIC SYSTEMS MAGAZINE LA English DT Article C1 USAF, Wright Lab, AAJP, Wright Patterson AFB, OH 45433 USA. Syst Res Labs Inc, Dayton, OH 45440 USA. RP Montgomery, JB (reprint author), USAF, Wright Lab, AAJP, Wright Patterson AFB, OH 45433 USA. NR 1 TC 1 Z9 1 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0885-8985 J9 IEEE AERO EL SYS MAG JI IEEE Aerosp. Electron. Syst. Mag. PD APR PY 1998 VL 13 IS 4 BP 29 EP 35 DI 10.1109/62.666834 PG 7 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA ZF702 UT WOS:000072923500009 ER PT J AU Melvin, W Wicks, M Antonik, P Salama, Y Li, P Schuman, H AF Melvin, W Wicks, M Antonik, P Salama, Y Li, P Schuman, H TI Knowledge-based space-time adaptive processing for airborne early warning radar SO IEEE AEROSPACE AND ELECTRONIC SYSTEMS MAGAZINE LA English DT Article AB This paper describes an innovative concept for knowledge-based control of space-time adaptive processing (STAP) for airborne early warning radar, The knowledge-based approach holds potential for significant performance improvements over classical STAP processing in nonhomogeneous environments by taking advantage of a priori knowledge. Under this approach, knowledge-based control is used to direct pre-adaptive filtering, and to carefully select STAP algorithms, parameters, and secondary data cells. C1 USAF, Res Lab, Washington, DC 20330 USA. Kaman Sci Corp, Colorado Springs, CO 80933 USA. Syracuse Res Corp, Syracuse, NY 13210 USA. RP Melvin, W (reprint author), USAF, Res Lab, Washington, DC 20330 USA. NR 8 TC 40 Z9 46 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0885-8985 J9 IEEE AERO EL SYS MAG JI IEEE Aerosp. Electron. Syst. Mag. PD APR PY 1998 VL 13 IS 4 BP 37 EP 42 DI 10.1109/62.666835 PG 6 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA ZF702 UT WOS:000072923500011 ER PT J AU Spitz, J Melloch, MR Cooper, JA Capano, MA AF Spitz, J Melloch, MR Cooper, JA Capano, MA TI 2.6 kV 4H-SiC lateral DMOSFET's SO IEEE ELECTRON DEVICE LETTERS LA English DT Article ID SEMICONDUCTOR AB A 4H-SiC lateral double-implanted metal-oxide-semiconductor (LDMOS) field effect transistor is fabricated in a lightly doped n-epilayer on an insulating 4H-SiC substrate, After depleting through the epilayer, the depletion region continues to move laterally toward the drain, The result is an increase in blocking voltage compared to a vertical DMOSFET fabricated in the same epilayer on a conducting substrate, A blocking voltage of 2.6 kV is obtained. nearly double the highest previously demonstrated blocking voltage for a SIC MOSFET. C1 Purdue Univ, Sch Elect & Comp Engn, W Lafayette, IN 47907 USA. USAF, Wright Lab, Mat Directorate, Wright Patterson AFB, OH 45433 USA. RP Spitz, J (reprint author), Purdue Univ, Sch Elect & Comp Engn, W Lafayette, IN 47907 USA. NR 13 TC 81 Z9 83 U1 2 U2 16 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0741-3106 J9 IEEE ELECTR DEVICE L JI IEEE Electron Device Lett. PD APR PY 1998 VL 19 IS 4 BP 100 EP 102 DI 10.1109/55.663527 PG 3 WC Engineering, Electrical & Electronic SC Engineering GA ZC336 UT WOS:000072567100002 ER PT J AU Dhondt, F Barrette, J Haese, N Rolland, PA Delage, SL AF Dhondt, F Barrette, J Haese, N Rolland, PA Delage, SL TI Finite-element electromagnetic characterization of parasitics in multifinger thermally shunted HBT's SO IEEE MICROWAVE AND GUIDED WAVE LETTERS LA English DT Article AB This letter describes a methodology to extract parasitic capacitances and evaluate losses in multifinger thermally shunted heterojunction bipolar transistors (HBT's) using three-dimensional (3-D) electromagnetic modeling. This method is based on the partitioning of the structure into zones of propagation, which simplifies the analysis of the computed scattering matrices, The approach is validated using on-wafer measurements of open-circuit test structures, This letter also addresses the impact of changes in device topology on parasitic coupling capacitance and association efficiency. C1 Inst Elect & Microelect Nord, F-59652 Villeneuve Dascq, France. Thomson CSF, LCR, F-91404 Orsay, France. USAF, Res Lab, Wright Patterson AFB, OH 45433 USA. RP Dhondt, F (reprint author), Inst Elect & Microelect Nord, F-59652 Villeneuve Dascq, France. NR 3 TC 2 Z9 2 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1051-8207 J9 IEEE MICROW GUIDED W JI IEEE Microw. Guided Wave Lett. PD APR PY 1998 VL 8 IS 4 BP 167 EP 169 DI 10.1109/75.663522 PG 3 WC Engineering, Electrical & Electronic SC Engineering GA ZE210 UT WOS:000072769100007 ER PT J AU Noble, MJ Shin, JH Choquette, KD Loehr, JP Lott, JA Lee, YH AF Noble, MJ Shin, JH Choquette, KD Loehr, JP Lott, JA Lee, YH TI Calculation and measurement of resonant-mode blueshifts in oxide-apertured VCSEL's SO IEEE PHOTONICS TECHNOLOGY LETTERS LA English DT Article DE cavity resonators; laser modes; optical resonators; semiconductor lasers; surface-emitting lasers ID SURFACE-EMITTING LASERS AB As the aperture size of oxide-apertured vertical-cavity surface-emitting lasers (VCSEL's) shrinks, the lasing wavelength blueshifts. We have calculated this effect using both a scalar effective index model and a full-vector weighted index model. Results were compared against experimental data fbr two different VCSEL designs emitting near 780 and 850 nm. We find that the full-vector weighted index calculation matches the data remarkably well, while the scalar effective index calculation underestimates the blueshift. C1 USAF, Inst Technol AFITENG, Wright Patterson AFB, OH 45433 USA. Korea Adv Inst Sci & Technol, Dept Phys, Taejon 305701, South Korea. Sandia Natl Labs, Ctr Cpd Semicond Sci & Technol, Albuquerque, NM 87185 USA. USAF, Avion Directorate WLAADP, Heterojunct Phys Branch, Wright Patterson AFB, OH 45433 USA. RP Noble, MJ (reprint author), USAF, Inst Technol AFITENG, Wright Patterson AFB, OH 45433 USA. RI Lee, Yong Hee/C-2015-2011 NR 10 TC 18 Z9 18 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1041-1135 J9 IEEE PHOTONIC TECH L JI IEEE Photonics Technol. Lett. PD APR PY 1998 VL 10 IS 4 BP 475 EP 477 DI 10.1109/68.662565 PG 3 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA ZD755 UT WOS:000072720300001 ER PT J AU Wright, MW Bossert, DJ AF Wright, MW Bossert, DJ TI Temporal dynamics and facet coating requirements of monolithic MOPA semiconductor lasers SO IEEE PHOTONICS TECHNOLOGY LETTERS LA English DT Article DE semiconductor device modeling; semiconductor lasers ID OSCILLATOR POWER-AMPLIFIER; OPTICAL AMPLIFIERS; BOOSTER AMPLIFIER; WAVELENGTH AB Dynamics of temporal instabilities in tapered broad-area semiconductor master oscillator/power amplifier lasers are experimentally investigated, multigigahertz self-pulsations are evident in the optical and temporal spectra along with coupled-cavity modes due to the finite output-facet reflectivity. From a previously developed time-dependent coupled-wave model, it is shown that by adjusting the grating strength in the distributed Bragg reflector (DBR) section of the master oscillator the antireflection facet coating requirements can be relaxed. Increased stable operation at high powers is then possible. C1 USAF, Phillips Lab, Semicond Laser Branch, Kirtland AFB, NM 87117 USA. Univ New Mexico, Ctr High Technol Mat, Albuquerque, NM 87131 USA. RP Wright, MW (reprint author), USAF, Phillips Lab, Semicond Laser Branch, Kirtland AFB, NM 87117 USA. NR 16 TC 10 Z9 10 U1 3 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1041-1135 J9 IEEE PHOTONIC TECH L JI IEEE Photonics Technol. Lett. PD APR PY 1998 VL 10 IS 4 BP 504 EP 506 DI 10.1109/68.662575 PG 3 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA ZD755 UT WOS:000072720300011 ER PT J AU Skinner, JP Kent, BM Wittmann, RC Mensa, DL Andersh, DJ AF Skinner, JP Kent, BM Wittmann, RC Mensa, DL Andersh, DJ TI Normalization and interpretation of radar images SO IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION LA English DT Article DE radar imaging AB Calibrated radar images are often quantified as radar cross section. This interpretation, which is not strictly correct, can lead to misunderstanding of test target scattering properties. To avoid confusion, we recommend that a term such as "scattering brightness" (defined below) be adopted as a standard label for image-domain data. C1 AF Inst Technol, Dept Elect & Comp Engn, Wright Patterson AFB, OH 45433 USA. USAF, Res Lab, Signature Technol Off, Wright Patterson AFB, OH 45433 USA. Natl Inst Stand & Technol, Boulder, CO 80303 USA. USN, Ctr Weap, Pt Mugu, CA USA. Demaco Inc, Champaign, IL 61820 USA. RP Skinner, JP (reprint author), Dept AF, Wright Patterson AFB, OH USA. NR 5 TC 4 Z9 4 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-926X J9 IEEE T ANTENN PROPAG JI IEEE Trans. Antennas Propag. PD APR PY 1998 VL 46 IS 4 BP 502 EP 506 DI 10.1109/8.664113 PG 5 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA ZG443 UT WOS:000073002800006 ER PT J AU de Graaf, PW Lehnert, JS AF de Graaf, PW Lehnert, JS TI Performance comparison of a slotted ALOHA DS/SSMA network and a multichannel narrow-band slotted ALOHA network SO IEEE TRANSACTIONS ON COMMUNICATIONS LA English DT Article; Proceedings Paper CT IEEE Military Communications Conference (MILCOM 94) CY OCT 02-05, 1994 CL FT MONMOUTH, NEW JERSEY SP IEEE DE access protocols; code-division multiaccess; packet radio; pseudonoise coded communication; stability ID RANDOM SIGNATURE SEQUENCES; THROUGHPUT; SYSTEMS; DELAY AB Throughput, delay, and stability for two slotted ALOHA packet radio systems are compared. One system is a slotted direct-sequence spread-spectrum multiple-access (DS/SSMA) network where each user employs a newly chosen random signature sequence for each bit in a transmitted packet. The other system is a multiple-channel slotted narrow-band ALOHA network where each packet is transmitted over a randomly selected channel. Accurate packet success probabilities for the code-division multiple-access (CDMA) system are computed using an improved Gaussian approximation technique which accounts for bit-to-bit error dependencies. Average throughput and delay results are obtained for the multiple-channel slotted ALOHA system and CDMA systems with block error correction. The first exit time (FET) is computed for both systems and used as a measure of the network stability. The CDMA system is shown to have better performance than the multiple-channel ALOHA system in all three areas. C1 USAF Acad, Colorado Springs, CO 80903 USA. Purdue Univ, Sch Elect & Comp Engn, W Lafayette, IN 47907 USA. RP de Graaf, PW (reprint author), USAF Acad, Colorado Springs, CO 80903 USA. NR 8 TC 37 Z9 37 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0090-6778 J9 IEEE T COMMUN JI IEEE Trans. Commun. PD APR PY 1998 VL 46 IS 4 BP 544 EP 552 DI 10.1109/26.664310 PG 9 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA ZJ061 UT WOS:000073175600021 ER PT J AU Reuter, CE Taflove, A Sathiaseelan, V Piket-May, M Mittal, BB AF Reuter, CE Taflove, A Sathiaseelan, V Piket-May, M Mittal, BB TI Unexpected physical phenomena indicated by FDTD modeling of the Sigma-60 deep hyperthermia applicator SO IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES LA English DT Article DE electromagnetic fields; FDTD; hyperthermia; modeling ID TIME-DOMAIN METHOD; CALCULATING EM ABSORPTION; REGIONAL HYPERTHERMIA; DIFFERENCE; SIMULATION; CIRCUITS; SYSTEMS; TD AB We investigate the numerical convergence properties of two-dimensional (2-D) and three-dimensional (3-D) finite-difference time-domain (FDTD) models of the BSD-2000 Sigma-60 annular phased array used for deep hyperthermia. The FDTD modeling data indicate unexpected physical phenomena for the case of Sigma-60 excitation of an elliptical tissue phantom embedded in a circular water bolus, These phenomena include: 1) high-Q energy storage; 2) electromagnetic (EM) mode flipping within the water bolus/phantom; and 3) whispering-gallery transmission of energy to the opposite side of the phantom relative to the exciting dipole pair, We conclude that these phenomena substantially impact the FDTD numerical modeling of this system, and further conclude that the whispering-gallery effect can impact clinical applications of the Sigma-60. C1 USAF, Res Lab, Rome, NY 13441 USA. Northwestern Univ, Dept Elect & Comp Engn, Evanston, IL 60208 USA. NW Mem Hosp, Dept Radiat Oncol, Chicago, IL 60611 USA. Univ Colorado, Dept Elect & Comp Engn, Boulder, CO 80302 USA. RP Reuter, CE (reprint author), USAF, Res Lab, Rome Res Site, Rome, NY 13441 USA. RI Taflove, Allen/B-7275-2009 NR 18 TC 13 Z9 14 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9480 J9 IEEE T MICROW THEORY JI IEEE Trans. Microw. Theory Tech. PD APR PY 1998 VL 46 IS 4 BP 313 EP 319 DI 10.1109/22.664132 PG 7 WC Engineering, Electrical & Electronic SC Engineering GA ZE684 UT WOS:000072819800001 ER PT J AU Felde, GW AF Felde, GW TI The effect of soil moisture on the 37 GHz microwave polarization difference index (MPDI) SO INTERNATIONAL JOURNAL OF REMOTE SENSING LA English DT Article ID VEGETATION INDEX; AVHRR DATA; EMISSION; RADIOMETERS; SAHEL; AREA AB Previous studies have shown that the 37 GHz microwave polarization difference index (MPDI) has an inverse nonlinear relationship to the normalized difference vegetation index (NDVI) with the MPDI(NDVI) being more sensitive to vegetation density under sparse (moderate) vegetation conditions. It has also been noted that soil moisture can have a significant influence on the MPDI. This study quantifies the effect of soil moisture on the MPDI using the RADTRAN model and comparison with measurements from a few geographically restricted (eastern USA) study sites. Model results show the MPDI increases with soil moisture but its sensitivity approaches zero when soil moisture values or vegetation densities are large. Results based on special sensor microwave/imager (SSM/I) measured values of MPDI, using the NDVI as a surrogate for vegetation density and an antecedent precipitation index (API) as a surrogate for soil moisture, were consistent with those based on the model. Linear equations, one for each of three categories of vegetation density, expressing MPDI as a function of API were derived based on SSM/I measurements. These equations demonstrate that soil moisture information can be extracted from the MPDI when the NDVI is used to account for the effect of vegetation and that the effect of soil moisture on the MPDI should be taken into account if it is to be used as a vegetation index. The potential to normalize MPDI values for variations in soil moisture is discussed. C1 USAF, Res Lab, VSBE, AFRL,Space Vehicles Directorate, Bedford, MA 01731 USA. RP Felde, GW (reprint author), USAF, Res Lab, VSBE, AFRL,Space Vehicles Directorate, Bedford, MA 01731 USA. NR 38 TC 7 Z9 11 U1 0 U2 0 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON EC4A 3DE, ENGLAND SN 0143-1161 J9 INT J REMOTE SENS JI Int. J. Remote Sens. PD APR PY 1998 VL 19 IS 6 BP 1055 EP 1078 DI 10.1080/014311698215603 PG 24 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA ZK386 UT WOS:000073315500004 ER PT J AU Schoeppner, GA Pagano, NJ AF Schoeppner, GA Pagano, NJ TI Stress fields and energy release rates in cross-ply laminates SO INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES LA English DT Article ID DELAMINATION; COMPOSITES; MODE AB A method to model the thermoelastic response of flat laminated composites using a large radius axisymmetric hollow layered cylinder model is presented. An axisymmetric concentric cylinder model and a flat laminate model, each based on Reissner's variational principle with equilibrium stress fields, are compared. The stress components and the governing equations of the axisymmetric concentric cylinder formulation for a cylinder of infinite radius are shown analytically to be equivalent to the flat laminate formulation. Numerical results for the axisymmetric free edge stress field are shown to be nearly identical to the flat laminate free edge stress field solution. Selected results for the elastic stress fields and energy release rates in composite laminates with free edge and/or internal delaminations and transverse cracking are presented. (C) 1998 Elsevier Science Ltd. C1 USAF, Res Lab, Mech & Surface Interact Branch, Nonmet Mat Div,Mat Directorate, Wright Patterson AFB, OH 45433 USA. RP Schoeppner, GA (reprint author), USAF, Res Lab, Mech & Surface Interact Branch, Nonmet Mat Div,Mat Directorate, 2941 P Stress,Suite 1, Wright Patterson AFB, OH 45433 USA. NR 19 TC 51 Z9 51 U1 0 U2 6 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0020-7683 J9 INT J SOLIDS STRUCT JI Int. J. Solids Struct. PD APR PY 1998 VL 35 IS 11 BP 1025 EP 1055 DI 10.1016/S0020-7683(97)00107-8 PG 31 WC Mechanics SC Mechanics GA YV981 UT WOS:000071883800005 ER PT J AU Viggiano, AA Arnold, ST Morris, RA AF Viggiano, AA Arnold, ST Morris, RA TI Reactions of mass-selected cluster ions in a thermal bath gas SO INTERNATIONAL REVIEWS IN PHYSICAL CHEMISTRY LA English DT Review ID NUCLEOPHILIC DISPLACEMENT-REACTIONS; HYDRATED ELECTRON CLUSTERS; PHASE SN2 REACTION; DYNAMICS COMPUTER-SIMULATIONS; ASSOCIATION RATE COEFFICIENTS; POTENTIAL-ENERGY FUNCTION; NEGATIVELY CHARGED WATER; REACTION-RATE CONSTANTS; X = OH; MOLECULE ASSOCIATION AB Technological developments of fast-flow tubes that led to major advances in the study of cluster ion reactions are reviewed, including the coupling of high-pressure cluster ion sources to flowing-afterglow and selected-ion flow tube (SIFT) instruments. Several areas of cluster ion chemistry that have been studied recently in our laboratory, using a SIFT instrument with a supersonic expansion ion source, are reviewed. Firstly the thermal destruction of cluster ions is highlighted by a discussion of the competition between electron detachment and thermal dissociation in hydrated electron clusters (H2O)(n)(-). Rates and activation energies for the thermal destruction (dissociation plus detachment) of these clusters are discussed. The reactivity of hydrated electron clusters with several neutral electron scavengers is also reviewed. Secondly cluster ion chemistry related to trace neutral detection of atmospheric species using chemical ionization mass spectrometry is discussed. Recent rate measurements needed for chemical ionization detection of SO2 and H2SO4 using CO3-(H2O)(n) ions are reviewed. Thirdly the effects of solvation on nucleophilic displacement (S(N)2) reactions are highlighted by the reactions of CH3Br with OH-(H2O)(n), Cl-(H2O)(n) and F-(H2O)(n). Our measurements show that rates of S(N)2 reactions decrease with increasing hydration, and the reactions preferentially lead to unhydrated products, corroborating previous experimental and theoretical studies. The cluster studies also demonstrate that, in the absence of a fast S(N)2 reaction channel, other mechanisms such as association and ligand switching can become important. In the reaction of Cl-(H2O)(n) with CH3Br, a reaction where ligand switching plays an important role, the interesting thermal dissociation of Cl-(CH3Br) product ions is discussed. Finally, the use of cluster reactivity studies to resolve issues about the detailed nature of solvation, that is whether the core ion is internally or externally solvated, is discussed. Size-dependent rate constants for the reactions of X-(H2O)(n) (X = F, Cl, Br or I) with Cl-2, and the reactions of OH-(H2O)(n) with CO2 and with HBr were used to determine the closing of initial solvation shells. C1 USAF, Res Lab, Space Vehicles Directorate, Battlespace Environm Div VSBP, Hanscom AFB, MA 01731 USA. RP Viggiano, AA (reprint author), USAF, Res Lab, Space Vehicles Directorate, Battlespace Environm Div VSBP, 29 Randolph Rd, Hanscom AFB, MA 01731 USA. NR 136 TC 45 Z9 45 U1 3 U2 15 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON EC4A 3DE, ENGLAND SN 0144-235X J9 INT REV PHYS CHEM JI Int. Rev. Phys. Chem. PD APR-JUN PY 1998 VL 17 IS 2 BP 147 EP 184 DI 10.1080/014423598230126 PG 38 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA ZQ123 UT WOS:000073824600002 ER PT J AU Gardner, LI Harrison, SH Hendrix, CW Blatt, SP Wagner, KF Chung, RCY Harris, RW Cohn, DL Burke, DS Mayers, DL AF Gardner, LI Harrison, SH Hendrix, CW Blatt, SP Wagner, KF Chung, RCY Harris, RW Cohn, DL Burke, DS Mayers, DL CA Military Med Consortium Appl Retroviral Res TI Size and duration of zidovudine benefit in 1003 HIV-infected patients: US Army, Navy, and Air Force natural history data SO JOURNAL OF ACQUIRED IMMUNE DEFICIENCY SYNDROMES AND HUMAN RETROVIROLOGY LA English DT Article DE HIV early stage natural history; zidovudine; HIV epidemiology ID IMMUNODEFICIENCY-VIRUS-INFECTION; CUBIC MILLIMETER; CONTROLLED TRIAL; CELL COUNTS; AIDS; PROGRESSION; THERAPY; AZT AB Objectives: The study's objectives were to determine the size and duration of benefits of early versus delayed versus late treatment with zidovudine (ZDV) on disease progression and mortality in HIV-infected patients, and whether patients rapidly progressing before ZDV treatment had a different outcome from those not rapidly progressing before ZDV. Design: The design was an inception cohort of 1003 HIV-infected patients. One hundred and seventy-four of the 1003 patients were treated before CD4 counts fell to 1400 x 10(9)/L, ("early treatment"); 183 of 1003 patients were treated after CD4 counts fell to <400 x 10(9)/L but before clinical disease developed ("delayed treatment"); and 646 of the 1003 patients had either been treated after clinical disease developed or had not been treated at all by the end of follow-up ("late treatment"). Outcomes were progression to clinical HIV disease and mortality. Results: The relative risk (RR) of progression for early versus delayed treatment was 0.58 (p < .03), and durability of ZDV benefits on progression was estimated at no more than 2.0 years; however, this estimate had wide confidence intervals. The RR of progression for delayed versus late treatment was 0.54 p < .0001, and durability of ZDV benefits was estimated at 1.74 years; this estimate had narrow confidence intervals. Survival was better for the early versus delayed treatment (RR = 0.55), but this difference was not statistically significant. In the subgroup of patients with more rapid CD4 decline prior to ZDV therapy, significant benefits on progression were observed for early versus delayed ZDV therapy (RR = 0.42, p = .02) and delayed versus late ZDV therapy (RR = 0.51; p = .0004). Duration of benefit was estimated to be 4.5 years (early versus delayed) and 1.7 years (delayed versus late). For patients with less rapid pre-ZDV decline in CD4 levels, a significant progression benefit was observed for delayed versus late therapy (RR = 0.50; p = .02). Duration of benefit in this subgroup was estimated to be 1.8 years. No significant benefit was found for early versus delayed treatment (RR = 1.12) in the less rapid pre-ZDV CD4 cell decline subgroup. Conclusions: Early treatment compared with delayed treatment was associated with a sizable reduction in HIV progression, but the duration of benefits was estimated to last only about 2 years. Delayed treatment compared with late treatment with ZDV was associated with substantial reduction of progression, but this reduction was also clearly limited in duration. Benefits on progression and mortality for the early treatment group were heavily dependent on the pre-ZDV CD4 slope. In the subgroup of patients with the most rapid pre-ZDV CD4 cell declines, the duration of benefit was much longer, possibly as long as 4 years. C1 Walter Reed Army Inst Res, Div Prevent Med, Washington, DC USA. USA, Med Dept Ctr & Sch, Clin Invest Regulatory Off, Ft Sam Houston, TX USA. Wilford Hall USAF Med Ctr, Dept Infect Dis, Lackland AFB, TX 78236 USA. USN, Natl Med Ctr, HIV Res Clin, Henry M Jackson Fdn, Bethesda, MD USA. Walter Reed Army Med Ctr, Dept Med, Infect Dis Serv, Washington, DC 20307 USA. Fitzsimons Army Med Ctr, Dept Clin Invest, Aurora, CO 80045 USA. Denver Hlth & Hosp, Denver Publ Hlth, Denver, CO USA. Walter Reed Army Inst Res, Div Retrovirol, Rockville, MD USA. USN, Med Res Inst, Bethesda, MD USA. RP Gardner, LI (reprint author), NIOSH, Div Safety Res, Anal & Field Evaluat Branch, 1095 Willowdale Rd, Morgantown, WV 26505 USA. RI Hendrix, Craig/G-4182-2014; OI Hendrix, Craig/0000-0002-5696-8665; /0000-0002-5704-8094 NR 25 TC 3 Z9 3 U1 0 U2 1 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 USA SN 1077-9450 J9 J ACQ IMMUN DEF SYND JI J. Acquir. Immune Defic. Syndr. Hum. Retrovirol. PD APR 1 PY 1998 VL 17 IS 4 BP 345 EP 353 PG 9 WC Immunology; Infectious Diseases SC Immunology; Infectious Diseases GA ZC552 UT WOS:000072592000009 PM 9525436 ER PT J AU Raouf, RA Palazotto, A AF Raouf, RA Palazotto, A TI Dynamic instability of tires under asymmetric loads SO JOURNAL OF AEROSPACE ENGINEERING LA English DT Article AB This paper presents an analytical procedure for predicting instability loads of composite tires using a simplified tire model. The tire is modeled as a closed composite torus with geometric nonlinearities. The equations of motion of the torus are derived using differential geometry, and the Galerkin procedure is used to discretize the spatial domain. The resulting equations are nonlinear ordinary differential equations with constant coefficients. However, the special form of these equations allows their reduction to linear ordinary differential equations with periodic coefficients. The Floquet theory is then used to determine the stability characteristics of these equations under various loads and an impact velocity loading. The torus is studied in two reinforcement configurations and various fiber volume fractions, Both configurations show a threshold value for the applied load at which the stability of the periodic solution is lost in a catastrophic manner. Both reinforcement schemes shows the same optimum value for fiber volume fraction at which the instability load is maximum. C1 USN Acad, Dept Engn Mech, Annapolis, MD 21402 USA. USAF, Inst Technol, Dept Aeronaut & Astronaut, Wright Patterson AFB, OH 45433 USA. NR 8 TC 1 Z9 1 U1 0 U2 1 PU ASCE-AMER SOC CIVIL ENGINEERS PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 USA SN 0893-1321 J9 J AEROSPACE ENG JI J. Aerosp. Eng. PD APR PY 1998 VL 11 IS 2 BP 32 EP 36 DI 10.1061/(ASCE)0893-1321(1998)11:2(32) PG 5 WC Engineering, Aerospace; Engineering, Civil SC Engineering GA ZC857 UT WOS:000072626000003 ER PT J AU Khot, NS AF Khot, NS TI Multicriteria optimization for design of structures with active control SO JOURNAL OF AEROSPACE ENGINEERING LA English DT Article ID MULTIOBJECTIVE DESIGN; ROBUSTNESS AB This paper describes a method to design a structure and control system simultaneously using a multiobjective optimization approach based on global criteria. The control system was based on a modified linear quadratic regulator (LQR) with bounds placed on the control forces to simulate limitations of real actuators. In the design of the control system, the state space equations were integrated using a Runge-Kutta method for a specified initial boundary condition. The structural weight, the weight of the actuators, the time required to suppress an initial disturbance, and the performance index were considered as different objective functions to be optimized. The design variables were the bounds on the maximum values of the control force, the cross-sectional areas of the structural elements, and elements of the weighting matrices in the control design. As an example to illustrate the application of the approach, a box beam idealized by rod elements was used. The actuators and sensors were collocated and assumed to be embedded in structural elements. The results are presented for optimum designs obtained by changing different parameters in the definition of the global criteria. C1 USAF, Res Lab, Air Vehicles Directorate, Res Aerosp Engn Struct Div, Wright Patterson AFB, OH 45433 USA. RP Khot, NS (reprint author), USAF, Res Lab, Air Vehicles Directorate, Res Aerosp Engn Struct Div, Wright Patterson AFB, OH 45433 USA. NR 20 TC 10 Z9 10 U1 0 U2 2 PU ASCE-AMER SOC CIVIL ENGINEERS PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 USA SN 0893-1321 J9 J AEROSPACE ENG JI J. Aerosp. Eng. PD APR PY 1998 VL 11 IS 2 BP 45 EP 51 DI 10.1061/(ASCE)0893-1321(1998)11:2(45) PG 7 WC Engineering, Aerospace; Engineering, Civil SC Engineering GA ZC857 UT WOS:000072626000005 ER PT J AU Harvey, HM Hanson, DM AF Harvey, HM Hanson, DM TI The application of the revised algorithm for the prediction of the formation of exhaust condensation trails by jet aircraft SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article AB Application is made of the Hanson and Hanson algorithm for contrail production to predict the presence of a contrail (condensation trail) by jet aircraft. Two databases are utilized, one based on the contiguous 48 states and the second centered on flights in Alaska. Verification is obtained for the validity of this algorithm. The concept of a contrail window is introduced to aid in the interpretation of the results obtained from the calculation. C1 Wright State Univ, Dept Phys, Dayton, OH 45435 USA. Elmendorf AFB, Operat Grp 3, Anchorage, AK USA. RP Harvey, HM (reprint author), Wright State Univ, Dept Phys, Dayton, OH 45435 USA. NR 4 TC 4 Z9 4 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD APR PY 1998 VL 37 IS 4 BP 436 EP 440 DI 10.1175/1520-0450(1998)037<0436:TAOTRA>2.0.CO;2 PG 5 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZD977 UT WOS:000072744700008 ER PT J AU Lipton, AE AF Lipton, AE TI Improved GOES sounder coverage of cloud-broken data fields SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID SATELLITE; RADIANCES AB Geostationary satellite sounder radiances have typically been averaged over several individual fields of view before the radiances are used for retrieving thermodynamic profiles or for assimilation in weather prediction models. The purpose of the averaging is to compensate for data noise. Cloudy fields of view are excluded from averaging. In areas without a sufficient number of clear fields of view, complete profiles are not retrieved. Clouds thus cause gaps in sounder coverage. This note describes an automated method to select a set of averaging areas for a given field of sounder data, such that the gaps in coverage caused by clouds are as small and as few as possible. Test results are shown, indicating that the method can provide substantially better coverage than is obtained with a commonly used method. C1 USAF, Res Lab, Opt Effects Div, Hanscom AFB, MA USA. RP Lipton, AE (reprint author), Atmospher & Environm Res Inc, 840 Mem Dr, Cambridge, MA 02139 USA. NR 7 TC 2 Z9 2 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD APR PY 1998 VL 37 IS 4 BP 441 EP 446 DI 10.1175/1520-0450(1998)037<0441:IGSCOC>2.0.CO;2 PG 6 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZD977 UT WOS:000072744700009 ER PT J AU Friedman, L Soref, RA Sun, G AF Friedman, L Soref, RA Sun, G TI Silicon-based interminiband infrared laser SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID QUANTUM-WELL STRUCTURES; CASCADE LASERS AB Simulations of a room-temperature p-i-p coherently strained Si0.5Ge0.5/Si superlattice quantum-parallel laser diode have been made, Calculations have been made of the local-in-k-space population inversion between the nonparabolic heavy-hole valence minibands, HH2 and HL1. Lasing is at 5.4 mu m and the optical dipole matrix element is 3.7 A. Analysis of radiative-and-phonon scattering between the "mixed" bands indicates a lifetime difference between the upper and lower states of 2.4 ps. At an injected current density of 5000 A/cm(2), a laser gain of 134 cm(-1) is calculated. (C) 1998 American Institute of Physics. [S0021-8979(98)05507-8]. C1 USAF, Sensors Directorate, Res Lab, Hanscom AFB, MA 01731 USA. Univ Massachusetts, Dept Phys, Boston, MA 02125 USA. RP Friedman, L (reprint author), USAF, Sensors Directorate, Res Lab, Hanscom AFB, MA 01731 USA. NR 15 TC 26 Z9 26 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD APR 1 PY 1998 VL 83 IS 7 BP 3480 EP 3485 DI 10.1063/1.366559 PG 6 WC Physics, Applied SC Physics GA ZD971 UT WOS:000072744100005 ER PT J AU Walters, TJ Ryan, KL Tehrany, MR Jones, MB Paulus, LA Mason, PA AF Walters, TJ Ryan, KL Tehrany, MR Jones, MB Paulus, LA Mason, PA TI HSP70 expression in the CNS in response to exercise and heat stress in rats SO JOURNAL OF APPLIED PHYSIOLOGY LA English DT Article DE heat shock protein 70; central nervous system; brain; electromagnetic fields; microwaves; thermoregulation; treadmill ID SHOCK MESSENGER-RNA; SKELETAL-MUSCLE; INVIVO HYPERTHERMIA; RABBIT CEREBELLUM; PROTEIN; LOCALIZATION; BRAIN; FAMILY; LIVER AB We have previously documented the regional distribution of 70-kDa heat shock protein (HSP70) in brains of rats made hyperthermic by brief exposure to high-powered microwaves (HPM; 2.06 GHz). We now compare HSP70 expression induced by HPM exposure to that induced by exertional and/or environmental heat stress. Rats were chronically implanted with a temperature probe guide in the hypothalamic region of the brain (T-br) After recovery, the following treatment groups were examined: HPM; sham exposed; treadmill exercise at room temperature (24 degrees C; Ex-1); treadmill exercise in a warm environment (34 degrees C; Ex-2); and sedentary groups (Sed-1 and Sed-2), in which ambient temperature was adjusted so that the T-br mimicked the T-br in the corresponding exercise groups. Significant HSP70 expression occurred only in the hyperthermic (Ex-2, Sed-2, and HPM) groups. The pattern of HSP70 expression was similar among Ex-2 and Sed-2 rats but differed from that in HPM rats. We conclude that 1) the pattern of HSP70 expression differs between HPM and non-microwave heating, and 2) exercise alone was not sufficient to induce central HSP70 expression. C1 USAF, AFRL, HEDR, Directed Energy Bioeffects Div, Brooks AFB, TX 78235 USA. Veridan Inc, USAF, Res Lab,Directed Energy Bioeffects Div, Human Effectiveness Directorate, Brooks AFB, TX USA. Trinity Univ, Dept Biol, San Antonio, TX 78212 USA. RP Walters, TJ (reprint author), USAF, AFRL, HEDR, Directed Energy Bioeffects Div, Bldg 1184,8308 Hawks Rd, Brooks AFB, TX 78235 USA. EM thomas.walters@aloer.brooks.af.mil NR 36 TC 31 Z9 31 U1 3 U2 3 PU AMER PHYSIOLOGICAL SOC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 USA SN 8750-7587 J9 J APPL PHYSIOL JI J. Appl. Physiol. PD APR PY 1998 VL 84 IS 4 BP 1269 EP 1277 PG 9 WC Physiology; Sport Sciences SC Physiology; Sport Sciences GA ZD714 UT WOS:000072716100023 PM 9516193 ER PT J AU Hlastala, MP Chornuk, MA Self, DA Kallas, HJ Burns, JW Bernard, S Polissar, NL Glenny, RW AF Hlastala, MP Chornuk, MA Self, DA Kallas, HJ Burns, JW Bernard, S Polissar, NL Glenny, RW TI Pulmonary blood flow redistribution by increased gravitational force SO JOURNAL OF APPLIED PHYSIOLOGY LA English DT Article DE fluorescent microspheres; cardiac output; pulmonary gas exchange; centrifuge; acceleration; gravity ID INTER-REGIONAL DISTRIBUTION; SPATIAL-DISTRIBUTION; GRAVITY; DOGS; LUNG; PERFUSION; POSTURE; ORIENTATION; EXERCISE; POSITION AB This study was undertaken to assess the influence of gravity on the distribution of pulmonary blood flow (PBF) using increased inertial force as a perturbation. PBF was studied in unanesthetized swine exposed to -G(x) (dorsal-to-ventral direction, prone position), where G is the magnitude of the force of gravity at the surface of the Earth, on the Armstrong Laboratory Centrifuge at Brooks Air Force Base. PBF was measured using 15-mu m fluorescent microspheres, a method with markedly enhanced spatial resolution. Each animal was exposed randomly to -1, -2, and -3 G(x). Pulmonary vascular pressures, cardiac output, heart rate, arterial blood gases, and PBF distribution were measured at each G level. Heterogeneity of PBF distribution as measured by the coefficient of variation of PBF distribution increased from 0.38 +/- 0.05 to 0.55 +/- 0.11 to 0.72 +/- 0.16 at -1, -2, and -3 G(x), respectively. At -1 G(x), PBF was greatest in the ventral and cranial and lowest in the dorsal and caudal regions of the lung. With increased -G(x), this gradient was augmented in both directions. Extrapolation of these values to 0 G predicts a slight dorsal (nondependent) region dominance of PBF and a coefficient of variation of 0.22 in microgravity. Analysis of variance revealed that a fixed component (vascular structure) accounted for 81% and nonstructure components (including gravity) accounted for the remaining 19% of the PBF variance across the entire experiment (all 3 gravitational levels). The results are inconsistent with the predictions of the zone model. C1 Univ Washington, Div Pulm & Crit Care Med, Dept Physiol & Biophys, Seattle, WA 98195 USA. Univ Washington, Dept Med, Seattle, WA 98195 USA. Univ Washington, Dept Anesthesiol, Seattle, WA 98195 USA. Mt Whisper Light Stat Consulting, Seattle, WA 98122 USA. USAF, Med Ctr, Armstrong Lab, Crew Technol Div, Brooks AFB, TX 78235 USA. RP Hlastala, MP (reprint author), Univ Washington, Div Pulm & Crit Care Med, Dept Physiol & Biophys, Box 356522, Seattle, WA 98195 USA. FU NHLBI NIH HHS [HL-12174, HL-24163] NR 31 TC 21 Z9 22 U1 0 U2 1 PU AMER PHYSIOLOGICAL SOC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 USA SN 8750-7587 J9 J APPL PHYSIOL JI J. Appl. Physiol. PD APR PY 1998 VL 84 IS 4 BP 1278 EP 1288 PG 11 WC Physiology; Sport Sciences SC Physiology; Sport Sciences GA ZD714 UT WOS:000072716100024 PM 9516194 ER PT J AU Sylvia, VL Schwartz, Z Curry, DB Chang, Z Dean, DD Boyan, BD AF Sylvia, VL Schwartz, Z Curry, DB Chang, Z Dean, DD Boyan, BD TI 1,25(OH)(2)D-3 regulates protein kinase C activity through two phospholipid-dependent pathways involving phospholipase A(2) and phospholipase C in growth zone chondrocytes SO JOURNAL OF BONE AND MINERAL RESEARCH LA English DT Article ID VITAMIN-D METABOLITES; EXTRACELLULAR-MATRIX VESICLES; ARACHIDONIC-ACID TURNOVER; CELL MATURATION; RESTING ZONE; NONGENOMIC REGULATION; ALKALINE-PHOSPHATASE; SIGNAL-TRANSDUCTION; RADIORECEPTOR ASSAY; CULTURES AB We have previously shown that 1,25-dihydroxyvitamin D-3 (1,25(OH)(2)D-3) plays a major role in growth zone chondrocyte (GC) differentiation and that this effect is mediated by protein kinase C (PKC). The aim of the present study nas to identify the signal transduction pathway used by 1,25(OH)(2)D-3 to stimulate PKC activation, Confluent, fourth passage GC cells from costochondral cartilage were used to evaluate the mechanism of PKC activation, Treatment of GC cultures, with 1,25(OH)(2)D-3 elicited a dose-dependent increase in both inositol-1,4,5-trisphosphate and diacylglycerol (DAG) production, suggesting a role for phospholipase C and potentially for phospholipase D, Addition of dioctanoylglycerol to plasma membranes isolated from GCs increased PKC activity, Neither pertussis toxin nor choleratoxin had an inhibitory effect on PKC activity in control or 1,25(OH)(2)D-3-treated GCs, indicating that neither G(i) nor G(s) proteins were involved, Phospholipase A(2) inhibitors, quinacrine, OEPC (selective for secretory phospholipase A(2)), and AACOCF(3) (selective for cytosolic phospholipase A(2)), and the cyclooxygenase inhibitor indomethacin decreased PKC activity, while the phospholipase A(2) activators melittin and mastoparan increased PKC activity in GC cultures, Arachidonic acid and prostaglandin E-2, two downstream products of phospholipase A(2) action, also increased PKC activity, These results indicate that 1,25(OH)(2)D-3-dependent stimulation of PKC activity is regulated by two distinct phospholipase-dependent mechanisms: production of DAG, primarily via phospholipase C and production of arachidonic acid via phospholipase A(2). C1 Univ Texas, Hlth Sci Ctr, Dept Orthopaed, San Antonio, TX 78284 USA. Univ Texas, Hlth Sci Ctr, Dept Periodont, San Antonio, TX 78284 USA. Univ Texas, Hlth Sci Ctr, Dept Biochem, San Antonio, TX 78284 USA. Wilford Hall USAF Med Ctr, Dept Periodont, San Antonio, TX 78236 USA. Hebrew Univ Jerusalem, Hadassah Fac Dent Med, Dept Periodont, Jerusalem, Israel. RP Boyan, BD (reprint author), Univ Texas, Hlth Sci Ctr, Dept Orthopaed, 7703 Floyd Curl Dr, San Antonio, TX 78284 USA. OI Dean, David/0000-0002-4512-9065 FU NIDCR NIH HHS [DE-05937, DE-08603] NR 51 TC 56 Z9 57 U1 0 U2 0 PU BLACKWELL SCIENCE INC PI MALDEN PA 350 MAIN ST, MALDEN, MA 02148 USA SN 0884-0431 J9 J BONE MINER RES JI J. Bone Miner. Res. PD APR PY 1998 VL 13 IS 4 BP 559 EP 569 DI 10.1359/jbmr.1998.13.4.559 PG 11 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA ZE554 UT WOS:000072805200004 PM 9556056 ER PT J AU Nicholas, T Kroupa, JL AF Nicholas, T Kroupa, JL TI Micromechanics analysis and life prediction of titanium matrix composites SO JOURNAL OF COMPOSITES TECHNOLOGY & RESEARCH LA English DT Article DE metal matrix composites (MMCs); micromechanics; life prediction; thermomechanical fatigue; constitutive model ID DAMAGE MECHANISMS; FATIGUE; BEHAVIOR AB The response of a unidirectional SCS-6/Ti-6Al-4V composite is evaluated under a range of isothermal fatigue (IF) and thermomechanical fatigue (TMF) conditions. Both processing and thermomechanical test conditions are simulated using a cylinder in cylinder code, FIDEP, which treats the fiber as thermoelastic while the matrix is characterized using a recent version of the Bodner-Partom constitutive law. Computed stresses and strains in the constituents are obtained after 10 cycles of loading and are used as input into a new and simpler version of a life fraction model. Applied stress at temperature and computed matrix strains are used for the time-dependent and matrix fatigue terms in the model, respectively. Cyclic stress-strain behavior of the matrix material is also computed and used, together with fatigue life data, to identify the governing mechanisms and to explain the observed trends in fatigue life as a function of frequency and applied stress level. Comparisons of fatigue behavior with that of SCS-6/Timetal 21S illustrate differences when tested under nominally similar conditions. C1 USAF, Res Lab, Wright Patterson AFB, OH 45433 USA. Res Applicat Inc, Dayton, OH USA. RP Nicholas, T (reprint author), USAF, Res Lab, Wright Patterson AFB, OH 45433 USA. NR 21 TC 4 Z9 4 U1 0 U2 1 PU AMER SOC TESTING MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DR, W CONSHOHOCKEN, PA 19428-2959 USA SN 0884-6804 J9 J COMPOS TECH RES JI J. Compos. Technol. Res. PD APR PY 1998 VL 20 IS 2 BP 79 EP 88 PG 10 WC Materials Science, Composites; Polymer Science SC Materials Science; Polymer Science GA 118YV UT WOS:000075869300001 ER PT J AU Robertson, DD Mall, S Lee, SM AF Robertson, DD Mall, S Lee, SM TI Strength reduction and damage characterization of SCS6/Ti-6Al-4V composite exposed to fatigue at elevated temperature SO JOURNAL OF COMPOSITES TECHNOLOGY & RESEARCH LA English DT Article DE titanium matrix composites; metal matrix composites; fatigue; residual strength; fatigue life; tensile loading; damage mechanisms ID TITANIUM MATRIX COMPOSITE; BEHAVIOR; MECHANISMS AB Effect of fatigue loading on the residual strength of a unidirectional titanium matrix composite, SCS6/Ti-6-4, was investigated. The composite was fatigued isothermally at 427 degrees C under load-controlled mode with an applied maximum stress of 900 MPa up to a certain fraction of the fatigue life, and then loaded monotonically to failure to obtain the residual strength. Two frequencies, 1 Hz and 0.01 Hz, were used to examine the time-dependent characteristics of the fatigue loading. Substantially different failure mechanisms and fatigue lives were observed, but the reduction in strength as a percentage of fatigue life was similar for the two cases. Practically no reduction in strength occurred until 75% of the expected fatigue life. C1 USAF, Dept Aeronaut & Astronaut, Inst Technol, Wright Patterson AFB, OH 45433 USA. RP Robertson, DD (reprint author), USAF, Dept Aeronaut & Astronaut, Inst Technol, Wright Patterson AFB, OH 45433 USA. NR 17 TC 2 Z9 2 U1 0 U2 0 PU AMER SOC TESTING MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DR, W CONSHOHOCKEN, PA 19428-2959 USA SN 0884-6804 J9 J COMPOS TECH RES JI J. Compos. Technol. Res. PD APR PY 1998 VL 20 IS 2 BP 120 EP 128 PG 9 WC Materials Science, Composites; Polymer Science SC Materials Science; Polymer Science GA 118YV UT WOS:000075869300005 ER PT J AU Chung, H Dudley, M Larson, DJ Hurle, DTJ Bliss, DF Prasad, V AF Chung, H Dudley, M Larson, DJ Hurle, DTJ Bliss, DF Prasad, V TI The mechanism of growth-twin formation in zincblende crystals: new insights from a study of magnetic liquid encapsulated Czochralski-grown InP single crystals SO JOURNAL OF CRYSTAL GROWTH LA English DT Article AB Synchrotron white beam X-ray topography (SWBXT) [1,2] [M. Dudley, in: Mater Res. Sec. Symp. Proc., vol. 307, 1993, p. 213; Encyclopedia of Applied Physics, vol. 21, 1997, p. 533] combined with chemical etching and Nomarski optical microscopy have been employed to investigate the phenomenon of twinning in sulfur-doped, MLEC-grown [100] InP single crystals. Results confirm the prediction of Hurle [Sir Charles Frank, OBE, FRS; on 80th Birthday tribute, 1991, p. 188; J. Crystal Growth 147 (1995) 239] that twins nucleate in regions where {111} edge facets are anchored to the three-phase boundary (TPB), and that twinning produces a {111} external facet on the shoulder region of crystal. factor the point at which the twin nucleates is observed to be the appearance of a {115} external shoulder facet which is then converted to the {111} external shoulder facet upon twinning. Based on the observation of both anchored edge facets and twinning at shoulder angles of approximately 74 degrees, v(max) the maximum in the range of angles, v (where v is the angle between the edge facet and the extension of the crystal surface, or shoulder), over which edge facets can be expected to be trapped at the TPB, as presented by Hurle, has been increased, from similar to 86.5 degrees to similar to 112 degrees, by modifying approximations made concerning the relevant physical parameters for the particular case of S-doped InP. A correction is made to an error in Hurle: the most dangerous grow-out angle for the occurrence of twinning in [100] oriented crystals. is 74.2 degrees and not 35.5 degrees. Also Hurle predicted that, in crystals with diamond cubic or zincblende structures, the range of v angles for edge facet pinning should encompass 70.5(3)degrees for twinning to be possible. This is here extended to the statement that it should encompass either 70.5(3)degrees and/or 109.47 degrees. Incidences of twinning were also observed to occur by a similar mechanism but one which involved the conversion of a {114} external shoulder facet to a {110} one. (C) 1998 Elsevier Science B.V. All rights reserved. C1 SUNY Stony Brook, Dept Mat Sci & Engn, Stony Brook, NY 11794 USA. Univ Bristol, HH Wills Phys Lab, Bristol BS8 1TL, Avon, England. USAF, Res Lab, Bedford, MA 01731 USA. SUNY Stony Brook, Dept Mech Engn, Stony Brook, NY 11794 USA. RP Dudley, M (reprint author), SUNY Stony Brook, Dept Mat Sci & Engn, Stony Brook, NY 11794 USA. NR 16 TC 21 Z9 25 U1 0 U2 16 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 APR PY 1998 VL 187 IS 1 BP 9 EP 17 DI 10.1016/S0022-0248(97)00843-9 PG 9 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA ZF755 UT WOS:000072929800002 ER PT J AU Ahoujja, M Mitchel, WC Elhamri, S Newrock, RS Mast, DB Redwing, JM Tischler, MA Flynn, JS AF Ahoujja, M Mitchel, WC Elhamri, S Newrock, RS Mast, DB Redwing, JM Tischler, MA Flynn, JS TI Transport coefficients of AlGaN/GaN heterostructures SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Article; Proceedings Paper CT 39th Electronic Materials Conference (EMC) CY 1997 CL COLORADA STATE UNIV, FT COLLINS, COLORADO HO COLORADA STATE UNIV DE AlGaN/GaN; heterostructure; transport ID 2-DIMENSIONAL ELECTRON-GAS; EFFECTIVE-MASS; CYCLOTRON-RESONANCE; SINGLE-PARTICLE; QUANTUM-WELLS; ALN; SPECTROSCOPY; INTERFACE AB We have experimentally determined the effective mass (m*) of GaN, the classical (tau(e)), and quantum (tau(q)) scattering times for a two-dimensional electron gas residing at the interface of an AlGaN/GaN heterostructure, using the Shubnikov-de Haas effect. The ratio of the two scattering times, tau(e)/tau(q), suggests that, at low temperatures, the scattering mechanism limiting the mobility is due to remote ionized impurities located in AlGaN. This study should provide sample growers with information useful for improving the quality of the nitride heterostuctures. C1 USAF, Wright Lab, MLPO, W PAFB, Wright Patterson AFB, OH 45433 USA. Univ Dayton, Dept Phys, Dayton, OH 45469 USA. Univ Cincinnati, Dept Phys, Cincinnati, OH 45221 USA. Adv Technol Mat Inc, Danbury, CT 06810 USA. RP Ahoujja, M (reprint author), USAF, Wright Lab, MLPO, W PAFB, Wright Patterson AFB, OH 45433 USA. NR 28 TC 3 Z9 3 U1 0 U2 1 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 USA SN 0361-5235 J9 J ELECTRON MATER JI J. Electron. Mater. PD APR PY 1998 VL 27 IS 4 BP 210 EP 214 DI 10.1007/s11664-998-0389-4 PG 5 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA ZJ744 UT WOS:000073248600012 ER PT J AU Capano, MA Ryu, S Melloch, MR Cooper, JA Buss, MR AF Capano, MA Ryu, S Melloch, MR Cooper, JA Buss, MR TI Dopant activation and surface morphology of ion implanted 4H and 6H silicon carbide SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Article; Proceedings Paper CT 39th Electronic Materials Conference (EMC) CY 1997 CL COLORADA STATE UNIV, FT COLLINS, COLORADO HO COLORADA STATE UNIV DE implant activation; ion implantation; silicon carbide AB The activation of ion-implanted B into 4H-SiC, and B, and Al into 6H-SiC is investigated. Complete activation of B implants into 4H-SiC is achieved by annealing at 1750 degrees C for 40 min in an Ar environment. Significant activation (>10%) is not achieved unless the annealing temperature is 1600 degrees C or greater. Sheet resistances of Al-implanted 6H-SiC annealed at 1800 degrees C are 32.2 k Omega/square, indicating high activation of Al at this temperature. Annealing conditions which result in good acceptor activation are shown to be damaging to the surface of either 4H- or 6H-SiC. Atomic force microscopy and Nomarski differential interference contrast optical microscopy are applied to characterize the surfaces of these polytypes. Roughening of the surfaces is observed following annealing in Ar, with measured roughnesses as large as 10.1 nm for B-implanted 4H-SiC annealed at 1700 degrees C for 40 min. Based on data obtained from these techniques, a model is proposed to describe the roughening phenomenon. The premise of the model is that SiC sublimation and mobile molecules enable the surface to reconfigure itself into an equilibrium form. C1 Purdue Univ, W Lafayette, IN 47907 USA. USAF, Res Lab, Mat Directorate, MLPO, Wright Patterson AFB, OH 45433 USA. RP Capano, MA (reprint author), Purdue Univ, 1285 Elect Engn Bldg, W Lafayette, IN 47907 USA. NR 13 TC 79 Z9 83 U1 1 U2 15 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 USA SN 0361-5235 J9 J ELECTRON MATER JI J. Electron. Mater. PD APR PY 1998 VL 27 IS 4 BP 370 EP 376 DI 10.1007/s11664-998-0417-4 PG 7 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA ZJ744 UT WOS:000073248600040 ER PT J AU Van Treuren, KW Barlow, DN Heiser, WH Wagner, MJ Forster, NH AF Van Treuren, KW Barlow, DN Heiser, WH Wagner, MJ Forster, NH TI Investigation of Vapor-Phase Lubrication in a gas turbine engine SO JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME LA English DT Article; Proceedings Paper CT 42nd International Gas Turbine and Aeroengine Congress and Exhibition CY JUN 02-05, 1997 CL ORLANDO, FLORIDA SP Int Gas Turbine Inst AB The liquid oil lubrication system of current aircraft jet engines accounts for approximately 10-15 percent of the total weight of the engine. It has long been a goal of the aircraft gas turbine industry to reduce this weight. Vapor-Phase Lubrication (VPL) is a promising technology to eliminate liquid oil lubrication. The current investigation resulted in the first gas turbine to operate in the absence of conventional liquid lubrication A phosphate ester, commercially known as DURAD 620B, was chosen for the test. Extensive research at Wright Laboratory demonstrated that this lubricant could reliably lubricate rolling element bearings in the gas turbine engine environment. The Allison T63 engine was selected as the test vehicle because of its small size and bearing configuration. Specifically, VPL was evaluated in the number eight bearing because it is located in a relatively hot environment, in line with the combustor discharge, and it can be isolated from the other bearings and the liquid lubrication system. The bearing was fully instrumented and its performance with standard oil lubrication was documented, Results of this baseline study were used to develop a thermodynamic model to predict the bearing temperature with VPL. The engine was then operated at a ground idle condition with VPL with the lubricant misted into the #8 bearing at 13 ml/h. The bearing temperature stabilized at 283 degrees C within 10 minutes. Engine operation was continued successfully for a total of one hour. No abnormal wear of the rolling contact surfaces was found when the bearing was later examined. Bearing temperatures after engine shutdown indicated the bearing had reached thermodynamic equilibrium with its surroundings during the test. After shutdown bearing temperatures steadily decreased without the soakback effect seen after shutdown in standard lubricated bearings. In contrast, the oil-lubricated bearing ran at a considerably lower operating temperature (83 degrees C) and was significantly heated by its surroundings after engine shutdown. In the baseline tests, the final bearing temperatures never reached that of the operating VPL system. C1 USAF Acad, Dept Aeronaut, Colorado Springs, CO 80840 USA. USAF, Fuels & Lubricat Div, Aero Propuls & Power Directorate, Wright Patterson AFB, OH 45433 USA. RP Van Treuren, KW (reprint author), USAF Acad, Dept Aeronaut, Colorado Springs, CO 80840 USA. NR 23 TC 15 Z9 15 U1 1 U2 3 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0742-4795 J9 J ENG GAS TURB POWER JI J. Eng. Gas. Turbines Power-Trans. ASME PD APR PY 1998 VL 120 IS 2 BP 257 EP 262 DI 10.1115/1.2818113 PG 6 WC Engineering, Mechanical SC Engineering GA ZM040 UT WOS:000073498700002 ER PT J AU Meier, PA Dooley, DP Jorgensen, JH Sanders, CC Huang, WM Patterson, JE AF Meier, PA Dooley, DP Jorgensen, JH Sanders, CC Huang, WM Patterson, JE TI Development of quinolone-resistant Campylobacter fetus bacteremia in human immunodeficiency virus-infected patients SO JOURNAL OF INFECTIOUS DISEASES LA English DT Article ID INVITRO EVALUATION; SUBSPECIES FETUS; SSP-FETUS; JEJUNI AB Campylobacter fetus subspecies fetus has been recognized as a cause of systemic illness in immunocompromised hosts, including relapsing bacteremia in human immunodeficiency virus (HIV)-infected patients, Acquired resistance to quinolone therapy, while reported for a variety of bacteria, including Campylobacter jejuni, has not been previously documented for C. fetus. Two cases of quinolone-resistant C. fetus bacteremia were detected in HIV-infected patients, Cloning and nucleotide sequencing of the C. fetus gyrA gene in the 2 resistant isolates demonstrated a G-to-T change that led to an Asp-to-Tyr amino acid substitution at a critical residue frequently associated with quinolone resistance. In addition, comparison of the pre-and posttreatment isolates from 1 patient documented outer membrane protein changes temporally linked with the development of resistance. Relapsing C. fetus infections in quinolone-treated HIV-infected patients may be associated with the acquisition of resistance to these agents, and this resistance may be multifactorial. C1 Univ Utah, Dept Oncol Sci, Salt Lake City, UT USA. Creighton Univ, Sch Med, Dept Med Microbiol, Omaha, NE 68178 USA. Univ Texas, Hlth Sci Ctr, Dept Pathol, San Antonio, TX 78284 USA. Univ Texas, Hlth Sci Ctr, Dept Med, San Antonio, TX 78284 USA. Wilford Hall USAF Med Ctr, Dept Infect Dis, Lackland AFB, TX 78236 USA. RP Dooley, DP (reprint author), Brooke Army Med Ctr, MCHE MDI Infect Dis, Ft Sam Houston, TX 78234 USA. NR 26 TC 14 Z9 15 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5801 S ELLIS AVENUE, CHICAGO, IL 60637 USA SN 0022-1899 J9 J INFECT DIS JI J. Infect. Dis. PD APR PY 1998 VL 177 IS 4 BP 951 EP 954 PG 4 WC Immunology; Infectious Diseases; Microbiology SC Immunology; Infectious Diseases; Microbiology GA ZD747 UT WOS:000072719400015 PM 9534967 ER PT J AU Lipscomb, JC Garrett, CM Snawder, JE AF Lipscomb, JC Garrett, CM Snawder, JE TI Use of kinetic and mechanistic data in species extrapolation of bioactivation: Cytochrome P-450 dependent trichloroethylene metabolism at occupationally relevant concentrations SO JOURNAL OF OCCUPATIONAL HEALTH LA English DT Article DE trichloroethylene; cytochrome P450; metabolism; microsomes; risk assessment; enzyme kinetics; toxicity; bioactivation; chloral hydrate ID ALKOXYRESORUFIN O-DEALKYLATION; LIVER-MICROSOMES; RAT-LIVER; ENZYME-ACTIVITY; MOUSE; MICE; ETHANOL; PHARMACOKINETICS; CARCINOGENICITY; HEPATOTOXICITY AB Trichloroethylene (TRI) is an industrial solvent and environmental contaminant; therefore exposure to TRI occurs in diverse human populations. TRI causes hepatocellular carcinoma in B6C3F1 mice, but not rats; this suggests that TRI may be metabolized differently in the two species. We investigated the metabolism of TRI and the effect of TRI on enzymatic activities indicative of specific cytochrome P450 (GYP) forms in hepatic microsomes from mice, rats and humans. Studies in microsomes estimated Michaelis-Menten kinetic parameters by saturation analysis. K-m values were 35.4, 55.5 and 24.6 mu M and V-max values were 5,425, 4,826 and 1,440 pmol/min/mg in pooled mouse, rat and human microsomes, respectively. TRI (1,000 ppm) inhibited CYP2E1 dependent activity in all three species and BROD activity in mice and rats; TRI (1,000 ppm) increased CYP1A1/1A2 activity, and had no effect on CYP2A activity. Inhibition studies with mouse hepatic microsomes demonstrated that TRI was a competitive inhibitor of CYP2E1, with K-i of 50 ppm. TRI noncompetitively inhibited CYP2B-dependent activities in the rat and mouse. Preincubation of microsomes with TRI and NADPH decreased the absorbence of GO-bound CYP in all three species, but the dose-dependence was most evident in mouse hepatic microsomes. These results have quantified the interspecies difference in GYP-dependent TRI bioactivation and indicate that under both equivalent and occupationally relevant (hepatic) exposure conditions the human is at less risk of forming toxic CYP-derived TRI metabolites. C1 USAF, Armstrong Lab, Div Toxicol, Brooks AFB, TX 78235 USA. Geocenters Inc, Newton Ctr, MA USA. NIOSH, Taft Lab, Ctr Dis Control & Prevent, Atlanta, GA USA. RP Lipscomb, JC (reprint author), US EPA, NCEA, 26 W Martin Luther King Dr,MS 117, Cincinnati, OH 45268 USA. NR 44 TC 17 Z9 17 U1 1 U2 2 PU JAPAN SOC OCCUPATIONAL HEALTH PI TOKYO PA 1-29-8 SHINJUKU, SHINJUKU-KU, TOKYO, 160, JAPAN SN 1341-9145 J9 J OCCUP HEALTH JI J. Occup. Health PD APR PY 1998 VL 40 IS 2 BP 110 EP 117 DI 10.1539/joh.40.110 PG 8 WC Public, Environmental & Occupational Health SC Public, Environmental & Occupational Health GA ZF800 UT WOS:000072934500003 ER PT J AU James, WJ Slabbekoorn, MA Edgin, WA Hardin, CK AF James, WJ Slabbekoorn, MA Edgin, WA Hardin, CK TI Correction of congenital malar hypoplasia using stereolithography for presurgical planning SO JOURNAL OF ORAL AND MAXILLOFACIAL SURGERY LA English DT Article ID CRANIOFACIAL SURGERY C1 Wilford Hall USAF Med Ctr, Dept Oral & Maxillofacial Surg, Lackland AFB, TX 78236 USA. Wilford Hall USAF Med Ctr, Dept Plast & Reconstruct Surg, Lackland AFB, TX 78236 USA. RP Edgin, WA (reprint author), 59 MDW-DSCO,2200 Bergquist Dr,Suite 1, Lackland AFB, TX 78236 USA. NR 11 TC 25 Z9 30 U1 0 U2 0 PU W B SAUNDERS CO PI PHILADELPHIA PA INDEPENDENCE SQUARE WEST CURTIS CENTER, STE 300, PHILADELPHIA, PA 19106-3399 USA SN 0278-2391 J9 J ORAL MAXIL SURG JI J. Oral Maxillofac. Surg. PD APR PY 1998 VL 56 IS 4 BP 512 EP 517 DI 10.1016/S0278-2391(98)90726-1 PG 6 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA ZE786 UT WOS:000072830800025 PM 9541356 ER PT J AU Rine, DC Sonnemann, RM AF Rine, DC Sonnemann, RM TI Investments in reusable software. A study of software reuse investment success factors SO JOURNAL OF SYSTEMS AND SOFTWARE LA English DT Article AB This research supports the thesis that there is a set of success factors which are common across organizations and have some predictability relationships to software reuse. For completeness, this research also investigated to see if software reuse had a predictive relationship to productivity and quality. The individual success factors were grouped into the following categories: management commitment, investment strategy, business strategy, technology transfer, organizational structure, process maturity, product-line approach, software architecture, availability of components, and quality of components. A questionnaire was developed to measure software reuse capability, productivity, quality, and the set of software reuse success factors. A survey was conducted to determine the state-of-the practice. The data from the survey was statistically analyzed to evaluate the relationships among reuse capability, productivity, quality, and the individual software reuse success factors. The results of the analysis showed some of the success factors to have a predictive relationship to software reuse capability. Software reuse capability also had a predictive relationship to productivity and quality. Based on the research results, the leading indicators of software reuse capability are: product-line approach, architecture which standardizes interfaces and data formats, common software architecture across the product-line, design for manufacturing approach, domain engineering, management which understands reuse issues, software reuse advocate(s) in senior management, state-of-the-art tools and methods, precedence of reusing high level software artifacts such as requirements and design versus just code reuse, and trace end-user requirements to the components which support them. (C) 1998 Elsevier Science Inc. All rights reserved. C1 George Mason Univ, Sch Informat Technol & Engn, Fairfax, VA 22030 USA. USAF, Omaha, NE 68123 USA. RP George Mason Univ, Sch Informat Technol & Engn, Fairfax, VA 22030 USA. EM drine@cs.gmu.edu NR 36 TC 34 Z9 35 U1 0 U2 3 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0164-1212 EI 1873-1228 J9 J SYST SOFTWARE JI J. Syst. Softw. PD APR PY 1998 VL 41 IS 1 BP 17 EP 32 DI 10.1016/S0164-1212(97)10003-6 PG 16 WC Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA ZR295 UT WOS:000073959800003 ER PT J AU Elston, DM AF Elston, DM TI Insect repellents: An overview SO JOURNAL OF THE AMERICAN ACADEMY OF DERMATOLOGY LA English DT Letter C1 Brooke Army Med Ctr, Wilford Hall USAF Med Ctr, Dept Dermatol, Combined Mil Med Ctr, San Antonio, TX USA. RP Elston, DM (reprint author), Brooke Army Med Ctr, Wilford Hall USAF Med Ctr, Dept Dermatol, Combined Mil Med Ctr, San Antonio, TX USA. NR 1 TC 2 Z9 2 U1 0 U2 3 PU MOSBY-YEAR BOOK INC PI ST LOUIS PA 11830 WESTLINE INDUSTRIAL DR, ST LOUIS, MO 63146-3318 USA SN 0190-9622 J9 J AM ACAD DERMATOL JI J. Am. Acad. Dermatol. PD APR PY 1998 VL 38 IS 4 BP 644 EP 645 PG 2 WC Dermatology SC Dermatology GA ZG324 UT WOS:000072990100028 PM 9555815 ER PT J AU Ruh, R Chizever, HM AF Ruh, R Chizever, HM TI Permittivity and permeability of mullite-SiC-whisker and spinel-SiC-whisker composites SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID ZIRCONIA AB Real and imaginary permittivity (epsilon' and epsilon", respectively) values were determined on mullite-silicon carbide whisker (mullite-SiCw) composites, mullite-ZrO2 composites, and spinel-SiCw composites, in the frequency range of 2-18 GHz, using a 14 mm coaxial air-line measurement system. Depending on the frequency, the addition of 30 vol% of SiCw to mullite increases epsilon' from 6.6-6.9 to 16-22 and increases epsilon' from 0 to 16-22. The addition of 32 vol% of SiCw to spinel increases epsilon' from 7.5-7.8 to 37-44 and increases epsilon" from 0 to 13-20. The addition of 21 vol% of ZrO2, to mullite increases epsilon" to similar to 9 but does not change epsilon". Real and imaginary permeability values were 1 and 0, which are within experimental error. C1 USAF, Wright Lab, Wright Patterson AFB, OH 45433 USA. RP Ruh, R (reprint author), Universal Technol Corp, Beavercreek, OH 45431 USA. NR 12 TC 7 Z9 7 U1 1 U2 7 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD APR PY 1998 VL 81 IS 4 BP 1069 EP 1070 PG 2 WC Materials Science, Ceramics SC Materials Science GA ZJ248 UT WOS:000073195000038 ER PT J AU Browning, SM Nivatvongs, S AF Browning, SM Nivatvongs, S TI Intraoperative abandonment of ileal pouch to anal anastomosis - The Mayo Clinic experience SO JOURNAL OF THE AMERICAN COLLEGE OF SURGEONS LA English DT Article; Proceedings Paper CT 83rd Annual Clinical Congress of the American-College-of-Surgeons CY OCT 12-17, 1997 CL CHICAGO, ILLINOIS SP Amer Coll Surgeons ID CHRONIC ULCERATIVE-COLITIS AB Background: Completion of the ileal pouch to anal anastomosis (IPAA) is neither always possible nor advisable based on intraoperative findings. This study was undertaken to document the incidence of and reasons for intraoperative abandonment of IPAA. in a series of over 1,700 attempts. Study Design: A retrospective review of the Mayo Clinic surgical index from January 1981 through December 1995. Patients with the preoperative diagnosis of chronic ulcerative colitis or familial adenomatous polyposis for whom IPAA was planned but not completed are the subject of this report. Comparison is made to patients with a completed IPAA. from the Mayo Clinic II)AA registry. Results: During a 15-year period, 1,789 IPAA attempts were made. Intraoperative abandonment occurred in 74 (4.1%). Patients in whom the operation was abandoned were older than patients in whom it was not (38 versus 33 years, p < 0.01), with age older than 40 years conferring a relative risk of 1.87 versus age younger than 40 (95% confidence interval, 1.19-2.94%). IPAA was abandoned for technical reasons in 32 (43%), intraoperative diagnosis of Crohn's disease in 27 (36%), colorectal cancer in 10 (14%), mesenteric desmoid in 3 (4%), and miscellaneous reasons in 2 (3%) patients. Fifty-one (69%) patients underwent proctocolectomy and ileostomy and 23 (31%) underwent sphincter preserving procedures. Of these, 2 underwent subsequent successful IPAA. Conclusions: Preoperative counseling for IPAA should include discussion of the risk of intraoperative abandonment (4.1%). Older patients are at increased risk. If the IPAA is abandoned for reversible reasons, preservation of the anal sphincter preserves the option of a subsequent IPAA. (C) 1998 by the American College of Surgeons. C1 Mayo Clin, Div Colon & Rectal Surg, Rochester, MN USA. RP Browning, SM (reprint author), Wilford Hall USAF Med Ctr, Dept Gen Surg, 59th MDW,2200 Berquist Dr,Suite 1, Lackland AFB, TX 78236 USA. NR 10 TC 24 Z9 25 U1 0 U2 0 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 1072-7515 J9 J AM COLL SURGEONS JI J. Am. Coll. Surg. PD APR PY 1998 VL 186 IS 4 BP 441 EP 445 DI 10.1016/S1072-7515(98)00056-8 PG 5 WC Surgery SC Surgery GA ZF772 UT WOS:000072931700015 PM 9544959 ER PT J AU Vallado, DA Carter, SS AF Vallado, DA Carter, SS TI Accurate orbit determination from short-arc dense observational data SO JOURNAL OF THE ASTRONAUTICAL SCIENCES LA English DT Article; Proceedings Paper CT 1997 AAS/AIAA Astrodynamics Conference CY AUG 04-07, 1997 CL SUN VALLEY, IDAHO SP Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut AB Requirements have existed for several decades for highly accurate satellite orbits. With increased computer power, simplified analytical techniques have lost most of their competitive edge and numerical techniques are experiencing wide-spread popularity. When coupled with increased accuracy requirements from commercial satellites owners and accurate computations for debris and close approach for the International Space Station, a reliable method must be found to form highly-accurate satellite state vectors. This paper explores one approach using dense observational data from short-arcs of geographically distributed sensor sites. In particular, dense observations (consisting of one observation per second for about two minutes) are analyzed to determine the accuracy that can be achieved via high fidelity, numerical, orbit-determination techniques. C1 USSPACECom AN, Peterson AFB, CO 80914 USA. USAF, Res Lab, Kirtland AFB, NM 87117 USA. RP Vallado, DA (reprint author), USSPACECom AN, 250 S Peterson Blvd,Suite 116, Peterson AFB, CO 80914 USA. NR 5 TC 11 Z9 16 U1 1 U2 2 PU AMER ASTRONAUTICAL SOC PI SPRINGFIELD PA 6352 ROLLING MILL PLACE SUITE 102, SPRINGFIELD, VA 22152 USA SN 0021-9142 J9 J ASTRONAUT SCI JI J. Astronaut. Sci. PD APR-JUN PY 1998 VL 46 IS 2 BP 195 EP 213 PG 19 WC Engineering, Aerospace SC Engineering GA 189DX UT WOS:000079889800004 ER PT J AU Whiteley, MR Welsh, BM Roggemann, MC AF Whiteley, MR Welsh, BM Roggemann, MC TI Limitations of Gaussian assumptions for the irradiance distribution in digital imagery: nonstationary image ensemble considerations SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION LA English DT Article ID MODELS AB Gaussian assumptions for the irradiance probability density in a digital image are often employed but rarely justified. We provide a mathematical justification for these assumptions and indicate the limitations of their use. Beginning with the context-dependent image ensemble considerations introduced by Hunt and Cannon [IEEE Trans. Syst. Man Cybern. SMC-6, 876 (1976)], such an ensemble is found to be accurately modeled as a Gaussian random process with nonstationary mean and nonstationary variance. An ensemble transformation is deduced and confirmed empirically that yields a Gaussian, zero-mean, unit-variance, ergodic random process. This conclusion leads to an image model that predicts that the distribution of image irradiance values after local mean removal is determined only by the distribution of local standard deviation values in the image. An analytic expression is derived for the probability density function of these irradiance values and is validated experimentally. This expression indicates that the distribution of image irradiance values after local mean removal may be assumed to be Gaussian only when the local standard deviation in an image is a nearly stationary quantity. (C) 1998 Optical Society of America. C1 USAF, Inst Technol, Dept Engn Phys, Wright Patterson AFB, OH 45433 USA. USAF, Inst Technol, Dept Elect & Comp Engn, Wright Patterson AFB, OH 45433 USA. Michigan Technol Univ, Dept Elect Engn, Houghton, MI 49931 USA. RP Whiteley, MR (reprint author), USAF, Inst Technol, Dept Engn Phys, 2950 P St,Bldg 640, Wright Patterson AFB, OH 45433 USA. NR 12 TC 6 Z9 6 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0740-3232 J9 J OPT SOC AM A JI J. Opt. Soc. Am. A-Opt. Image Sci. Vis. PD APR PY 1998 VL 15 IS 4 BP 802 EP 810 DI 10.1364/JOSAA.15.000802 PG 9 WC Optics SC Optics GA ZD744 UT WOS:000072719100004 ER PT J AU Whiteley, MR Roggemann, MC Welsh, BM AF Whiteley, MR Roggemann, MC Welsh, BM TI Temporal properties of the Zernike expansion coefficients of turbulence-induced phase aberrations for aperture and source motion SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION LA English DT Article ID ATMOSPHERIC-TURBULENCE; MODAL COMPENSATION; POLYNOMIALS; TELESCOPES AB Zernike polynomials are often used to analyze turbulence-induced optical phase aberrations. Previous investigations have examined the spatial and temporal characteristics of the expansion coefficients of the turbulence-induced optical phase with respect to these polynomials. The results of these investigations are valid only for certain geometries and atmospheric models and do not take into account the effects of relative motion between the sensor and the object of interest. We introduce a generalized analysis geometry and use this aperture-and-source geometry with conventional methods to arrive at a general expression for the interaperture cross correlation of the Zernike coefficients. Aperture-and-source motion considerations are introduced to derive an expression for the temporal cross correlation and cross power spectra of these expansion coefficients. Temporal correlation and spectrum results are presented for several low-order Zernike modes, given certain aperture-and-source motions. (C) 1998 Optical Society of America. C1 USAF, Inst Technol, Dept Engn Phys, Wright Patterson AFB, OH 45433 USA. Michigan Technol Univ, Dept Elect Engn, Houghton, MI 49931 USA. USAF, Inst Technol, Dept Elect & Comp Engn, Wright Patterson AFB, OH 45433 USA. RP Whiteley, MR (reprint author), USAF, Inst Technol, Dept Engn Phys, 2950 P St,Bldg 640, Wright Patterson AFB, OH 45433 USA. NR 21 TC 17 Z9 20 U1 2 U2 2 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0740-3232 J9 J OPT SOC AM A JI J. Opt. Soc. Am. A-Opt. Image Sci. Vis. PD APR PY 1998 VL 15 IS 4 BP 993 EP 1005 DI 10.1364/JOSAA.15.000993 PG 13 WC Optics SC Optics GA ZD744 UT WOS:000072719100022 ER PT J AU Dickinson, TJ Bowman, WJ Stoyanof, M AF Dickinson, TJ Bowman, WJ Stoyanof, M TI Performance of liquid metal heat pipes during a space shuttle flight SO JOURNAL OF THERMOPHYSICS AND HEAT TRANSFER LA English DT Article ID FROZEN STATE; STARTUP AB This study investigated liquid metal heat pipe performance in a microgravity environment. Three stainless-steel/potassium heat pipes were down on Space Shuttle mission STS-77 in May 1996. The objectives of the experiment were to characterize the frozen startup and restart transients, to compare the flight and ground test data to establish a performance baseline for analytical model validation, and to assess the three different heat pipe designs. Microgravity operation did not adversely impact the startup or restart behavior of the heat pipes. The heat pipes operated within the predicted performance envelopes. The three designs had distinct startup characteristics, yet were similar in steady-state performance. These results will serve as a benchmark for further liquid metal heat pipe studies and space system applications. C1 USAF, Inst Technol, Dept Aeronaut & Astronaut, Wright Patterson AFB, OH 45433 USA. Brigham Young Univ, Dept Mech Engn, Provo, UT 84602 USA. USAF, Phillips Lab, Kirtland AFB, NM 87117 USA. RP Dickinson, TJ (reprint author), USAF, Inst Technol, Dept Aeronaut & Astronaut, Wright Patterson AFB, OH 45433 USA. NR 20 TC 2 Z9 2 U1 0 U2 2 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0887-8722 J9 J THERMOPHYS HEAT TR JI J. Thermophys. Heat Transf. PD APR-JUN PY 1998 VL 12 IS 2 BP 263 EP 269 DI 10.2514/2.6330 PG 7 WC Thermodynamics; Engineering, Mechanical SC Thermodynamics; Engineering GA ZG837 UT WOS:000073045000018 ER PT J AU Cross, CA Cespedes, RD McGuire, EJ AF Cross, CA Cespedes, RD McGuire, EJ TI Our experience with pubovaginal slings in patients with stress urinary incontinence SO JOURNAL OF UROLOGY LA English DT Article DE urinary incontinence, stress; surgery ID MANAGEMENT; SURGERY AB Purpose: Pubovaginal slings successfully treat stress urinary incontinence in women with intrinsic sphincter deficiency. Because of its durability, it has been an attractive procedure in select patients with urethral hypermobility. We examine our experience with pubovaginal sling. Materials and Methods: A total of 150 patients were evaluated for pelvic prolapse and urinary incontinence. An abdominal leak point pressure was determined in all patients. Of patients with type II stress urinary incontinence, 36 patients (80%) underwent additional gynecological procedures at the time of the pubovaginal sling, compared to 29% with intrinsic sphincter deficiency and 33% with coexisting urethral hypermobility and intrinsic sphincter deficiency. Results: The overall cure rate was 93% with a mean followup of 22 months. At 1 week postoperatively spontaneous voiding was accomplished by 56% of the patients with urethral hypermobility and 57% with intrinsic sphincter deficiency. Only 2.8% of patients required surgical therapy for prolonged urinary retention. De novo urgency/urge incontinence occurred in 19% of women with a 3% incidence of persistent urge incontinence. Conclusions: Pubovaginal slings are effective and durable. Voiding dysfunction is uncommon and is temporary in most patients. C1 Univ Texas, Sch Med, Div Urol, Houston, TX USA. Univ Texas, Sch Med, Dept Obstet Gynecol & Reprod Med, Houston, TX USA. Wilford Hall USAF Med Ctr, Dept Urol, PSSU, Lackland AFB, TX 78236 USA. RP Cross, CA (reprint author), Univ Texas, Sch Med, Div Urol, Houston, TX USA. NR 22 TC 102 Z9 105 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 USA SN 0022-5347 J9 J UROLOGY JI J. Urol. PD APR PY 1998 VL 159 IS 4 BP 1195 EP 1198 DI 10.1016/S0022-5347(01)63553-5 PG 4 WC Urology & Nephrology SC Urology & Nephrology GA ZB163 UT WOS:000072442700025 PM 9507831 ER PT J AU Cross, CA Cespedes, RD English, SF McGuire, EJ AF Cross, CA Cespedes, RD English, SF McGuire, EJ TI Transvaginal urethrolysis for urethral obstruction after anti-incontinence surgery SO JOURNAL OF UROLOGY LA English DT Article DE urethral obstruction; urinary incontinence; surgery ID STRESS URINARY-INCONTINENCE; MARSHALL-MARCHETTI-KRANTZ; SUSPENSION; MANAGEMENT; OPERATION; FEMALE AB Purpose: Urethral obstruction following a stress incontinence procedure occurs in 5 to 20% of patients. We examine the success of transvaginal urethrolysis in resolving voiding dysfunction. Materials and Methods: A retrospective chart review was performed on 39 patients who had undergone transvaginal urethrolysis for urethral obstruction following an anti-incontinence procedure. Preoperatively, a history was taken, and pelvic examination and either video urodynamics or cystoscopy were done. Results: All 39 patients complained of urge incontinence, 13% had urinary retention, 51% had incomplete bladder emptying and 36% voided to completion but had irritative voiding symptoms. Previous surgery included retropubic urethropexy in 41% of the cases, pubovaginal sling in 38% and bladder neck suspension in 21%. Mean length of followup after urethrolysis was 16 months. Of the 39 patients 33 (85%) had resolution of urge incontinence but 5 still required occasional intermittent catheterization. The remaining 6 patients had continued urge incontinence. An augmentation procedure was performed in 4 patients with improvement of symptoms. Conclusions: Our data support transvaginal urethrolysis for the treatment of iatrogenic urethral obstruction. It is a rapid, effective and minimally invasive technique that should be considered if voiding dysfunction does not resolve spontaneously. C1 Univ Texas, Sch Med, Dept Obstet Gynecol & Reprod Med, Houston, TX USA. Univ Texas, Sch Med, Div Urol, Houston, TX USA. Wilford Hall USAF Med Ctr, Dept Urol, PSSU, Lackland AFB, TX 78236 USA. RP Cross, CA (reprint author), Univ Texas, Sch Med, Dept Obstet Gynecol & Reprod Med, Houston, TX USA. NR 13 TC 64 Z9 68 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 USA SN 0022-5347 J9 J UROLOGY JI J. Urol. PD APR PY 1998 VL 159 IS 4 BP 1199 EP 1201 DI 10.1016/S0022-5347(01)63554-7 PG 3 WC Urology & Nephrology SC Urology & Nephrology GA ZB163 UT WOS:000072442700026 PM 9507832 ER PT J AU Puffer, RL AF Puffer, RL TI The Falklands sting: Reagan, Thatcher, and Argentina's bomb SO LIBRARY JOURNAL LA English DT Book Review C1 USAF, Hist Prog, Victorville, CA 92393 USA. RP Puffer, RL (reprint author), USAF, Hist Prog, Victorville, CA 92393 USA. NR 1 TC 0 Z9 0 U1 1 U2 1 PU BOWKER MAGAZINE GROUP CAHNERS MAGAZINE DIVISION PI NEW YORK PA 249 W 17TH ST, NEW YORK, NY 10011 USA SN 0363-0277 J9 LIBR J JI Libr. J. PD APR 1 PY 1998 VL 123 IS 6 BP 106 EP + PG 2 WC Information Science & Library Science SC Information Science & Library Science GA ZE123 UT WOS:000072760000130 ER PT J AU Pandey, AB Majumdar, BS Miracle, DB AF Pandey, AB Majumdar, BS Miracle, DB TI Effects of thickness and precracking on the fracture toughness of particle-reinforced Al-alloy composites SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article ID METAL-MATRIX COMPOSITE; CRACK INITIATION; GROWTH TOUGHNESS; DEFORMATION; PRESSURE; STEELS; STRESS; SIZE AB The effect of specimen thickness on the fracture toughness of a powder metallurgically processed 7093 Al/SiC/15p composite was evaluated in different microstructural conditions. The fracture toughness in the underaged condition increased significantly with a decrease in specimen thickness, even at thicknesses well below the value specified by ASTM-E 813 for a valid J(Ic) test. The influence of thickness was considerably lower in the peak-aged (PA) condition. This relative insensitivity is believed to be due to the low strain to failure associated with severe flow localization in the PA condition. The effect of precracking on the fracture toughness of discontinuously reinforced aluminum (DRA) was also evaluated. The dependence of fracture toughness on specimen thickness and precracking is explained in terms of the hydrostatic stress, which has a strong influence on the plastic straining capability of the DRA material. The fracture toughness was modeled using a critical strain formulation, with the void growth strain dependent on hydrostatic stress through the Rice and Tracey model. The predicted toughnesses for the thick and thin specimens were in good agreement with the experimental data. C1 Systran Corp, Dayton, OH 45432 USA. USAF, Res Lab, Mat & Mfg Directorate, Wright Patterson AFB, OH 45433 USA. RP Pandey, AB (reprint author), Systran Corp, Dayton, OH 45432 USA. NR 29 TC 21 Z9 27 U1 3 U2 14 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 USA SN 1073-5623 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD APR PY 1998 VL 29 IS 4 BP 1237 EP 1243 DI 10.1007/s11661-998-0250-7 PG 7 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA ZK623 UT WOS:000073343700011 ER PT J AU Warrier, SG Krishnamurthy, S Smith, PR AF Warrier, SG Krishnamurthy, S Smith, PR TI Oxidation protection of Ti-aluminide orthorhombic alloys: An engineered multilayer approach SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article ID COMPOSITES; INTERFACE; BEHAVIOR; FATIGUE AB The lack of high-temperature environmental resistance is a major issue in the application of orthorhombic-based titanium aluminide alloys (O alloys) and their composites. Improvement in environmental capability can be achieved by applying diffusion barrier coatings to the surface of the orthorhombic matrix alloy. However, since thin coatings are prone to foreign-object damage, an approach based on thicker multilayer materials may be more prudent for fracture-critical applications. In the present study, foils of the orthorhombic alloy were diffusion bonded on either side with an gamma alloy, the latter used in an attempt to provide environmental protection. Mechanical tests suggested that the gamma alloy was successful in preventing degradation of the O alloy due to oxidation and interstitial embrittlement under thermal cycling conditions. Processing below the beta transus of the O alloy provided an improvement in the stress and strain to failure of the joined material compared to materials processed above the transus. However, in either case, the strengths of the joined materials were significantly lower than that of the uncoated O alloy with similar microstructures. Results suggest that the low strength of the joined materials may be due to cracking of the gamma alloy, resulting in premature failure of the O alloy. Finite element analysis (FEA) was performed to understand the stress distribution in the joined material and to investigate approaches for reducing the residual stress. Several approaches for improving the stress and strain to failure of the joined material are presented. C1 Universal Energy Syst Inc, Dayton, OH 45432 USA. USAF, Res Lab, Mat & Mfg Directorate, Wright Patterson AFB, OH 45433 USA. RP Warrier, SG (reprint author), Universal Energy Syst Inc, Dayton, OH 45432 USA. NR 27 TC 15 Z9 15 U1 3 U2 6 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 USA SN 1073-5623 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD APR PY 1998 VL 29 IS 4 BP 1279 EP 1288 DI 10.1007/s11661-998-0254-3 PG 10 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA ZK623 UT WOS:000073343700015 ER PT J AU Noah, DL Sobel, AL Ostroff, SM Kildew, JA AF Noah, DL Sobel, AL Ostroff, SM Kildew, JA TI Biological warfare training: Infectious disease outbreak differentiation criteria SO MILITARY MEDICINE LA English DT Article AB The threat of biological terrorism and warfare may increase as the availability of weaponizable agents increases, the relative production costs of these agents decrease, and, most importantly, there exist terrorist groups willing to use them, Therefore, an important consideration during the current period of heightened surveillance for emerging infectious diseases is the ability to differentiate between natural and intentional outbreaks, Certain attributes of a disease outbreak, although perhaps not pathognomonic for a biological attack when considered singly, may combine to provide convincing evidence of intentional causation, These potentially differentiating criteria include proportion of combatants at risk, temporal patterns of illness onset, number of cases, clinical presentation, strain/variant, economic impact, geographic location, morbidity/mortality, antimicrobial resistance patterns, seasonal distribution, zoonotic potential, residual infectivity/toxicity, prevention/therapeutic potential, route of exposure, weather/climate conditions, incubation period, and concurrence with belligerent activities of potential adversaries. C1 AF Med Operat Agcy SGPA, Bolling AFB, DC 20332 USA. RP Noah, DL (reprint author), AF Med Operat Agcy SGPA, 170 Luke Ave,Suite 400, Bolling AFB, DC 20332 USA. NR 10 TC 18 Z9 18 U1 0 U2 0 PU ASSN MILITARY SURG US PI BETHESDA PA 9320 OLD GEORGETOWN RD, BETHESDA, MD 20814 USA SN 0026-4075 J9 MIL MED JI Milit. Med. PD APR PY 1998 VL 163 IS 4 BP 198 EP 201 PG 4 WC Medicine, General & Internal SC General & Internal Medicine GA ZG349 UT WOS:000072992700004 PM 9575761 ER PT J AU Jex, TT Lombard, T AF Jex, TT Lombard, T TI Psychosocial factors associated with smoking in air force recruits SO MILITARY MEDICINE LA English DT Article ID TOBACCO-USE; ADOLESCENT AB The ability to identify modifiable risk factors associated with smoking in U.S. Air Force recruits may prove useful in developing smoking prevention programs. We assessed 257 recruits for selected psychosocial factors previously found to be associated with smoking in young adults in the general population, Cross-sectional analysis revealed significant differences between smokers and nonsmokers for six of the eight factors addressed. Implications for the development of smoking prevention programs are discussed. C1 USAF, Sch Aerosp Med, Brooks AFB, TX 78235 USA. RP Jex, TT (reprint author), USAF, Sch Aerosp Med, 2513 Kennedy Circle, Brooks AFB, TX 78235 USA. NR 18 TC 1 Z9 1 U1 0 U2 0 PU ASSN MILITARY SURG US PI BETHESDA PA 9320 OLD GEORGETOWN RD, BETHESDA, MD 20814 USA SN 0026-4075 J9 MIL MED JI Milit. Med. PD APR PY 1998 VL 163 IS 4 BP 222 EP 225 PG 4 WC Medicine, General & Internal SC General & Internal Medicine GA ZG349 UT WOS:000072992700009 PM 9575766 ER PT J AU Niemeyer, DM AF Niemeyer, DM TI Polymerase chain reaction: A link to the future SO MILITARY MEDICINE LA English DT Article ID ENZYMATIC AMPLIFICATION; DNA AB Polymerase chain reaction (PCR) is a multi-faceted technology that is advancing disease detection, For pathology and clinical laboratories, PCR will be the tool of choice into the next century as scientists continue to develop and refine new uses. An amazingly simple process that amplifies nucleic acid sequences, PCR will change the practice of medicine because it will play a role in all aspects of the patient care continuum from diagnosis to treatment monitoring, Some striking applications range from detecting infectious and inherited diseases to assessing pharmacologic interventions. Additionally, the remarkable sensitivity of PCR will allow determination of a patient's genetic predisposition to diseases, thereby improving prevention modalities. Thus, medical practitioners should gain a basic understanding of this phenomenal cornerstone of molecular diagnostics. This article briefly reviews the history, theory, and uses of PCR and discusses relevant applications for military medicine. RP Niemeyer, DM (reprint author), Clin Invest Facil, Med Grp 60, 101 Bodin Circle, Travis AFB, CA 94535 USA. NR 24 TC 5 Z9 5 U1 0 U2 1 PU ASSN MILITARY SURG US PI BETHESDA PA 9320 OLD GEORGETOWN RD, BETHESDA, MD 20814 USA SN 0026-4075 J9 MIL MED JI Milit. Med. PD APR PY 1998 VL 163 IS 4 BP 226 EP 228 PG 3 WC Medicine, General & Internal SC General & Internal Medicine GA ZG349 UT WOS:000072992700010 PM 9575767 ER PT J AU Callison, GM Matthews, B AF Callison, GM Matthews, B TI A system for tracking dental readiness in the air force reserve SO MILITARY MEDICINE LA English DT Article AB The potential of dental emergencies to reduce combat effectiveness is a major concern of military planners, The dental fitness classification is the primary measure of an airman's dental readiness. A dental class 3 identification means that the airman has a dental condition that is likely to cause a dental emergency within 12 months, With few exceptions, Air Force Reserve command units are using only nonstandardized, manual tracking systems to ensure that identified members get needed dental treatment completed in a timely manner, The reliability and effectiveness of this process has been questioned in recent years. The importance of accurately recording the dental class status and having a reliable means to track dental treatment compliance of members designated dental class 3 is essential to maintaining a high state of dental readiness, A computerized tracking system called the Reserve Dental Data System was designed and developed to address this problem. C1 HG AFRC SGD, Robins AFB, GA 31098 USA. RP Callison, GM (reprint author), HG AFRC SGD, 155 2nd St, Robins AFB, GA 31098 USA. NR 6 TC 2 Z9 4 U1 0 U2 0 PU ASSN MILITARY SURG US PI BETHESDA PA 9320 OLD GEORGETOWN RD, BETHESDA, MD 20814 USA SN 0026-4075 J9 MIL MED JI Milit. Med. PD APR PY 1998 VL 163 IS 4 BP 239 EP 243 PG 5 WC Medicine, General & Internal SC General & Internal Medicine GA ZG349 UT WOS:000072992700013 PM 9575770 ER PT J AU Sabanegh, ES AF Sabanegh, ES TI The Costabile/Spevak article reviewed SO ONCOLOGY-NEW YORK LA English DT Editorial Material ID NONOBSTRUCTIVE AZOOSPERMIA; HODGKINS-DISEASE; TUMOR RP Sabanegh, ES (reprint author), Wilford Hall USAF Med Ctr, Dept Urol, San Antonio, TX 78236 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU P R R INC PI HUNTINGTON PA 17 PROSPECT ST, HUNTINGTON, NY 11743 USA SN 0890-9091 J9 ONCOLOGY-NY JI Oncology-NY PD APR PY 1998 VL 12 IS 4 BP 568 EP + PG 2 WC Oncology SC Oncology GA ZK407 UT WOS:000073317800018 ER PT J AU Iaconis, C Walmsley, IA AF Iaconis, C Walmsley, IA TI Fundamental-harmonic phase shift compensation in an intracavity frequency doubled Nd : YLF laser SO OPTICS COMMUNICATIONS LA English DT Article DE intracavity frequency doubling; Nd : YLF; LBO ID CONTINUOUS-WAVE; SOLID-STATE; GREEN; GENERATION AB We demonstrate a simple method for controlling the fundamental-harmonic phase shift in standing wave intracavity frequency doubled lasers. The technique takes advantage of the dispersion in glass rather than that of air, requiring only the rotation of a glass block through a few degrees in order to compensate for phase shifts of up to pi. (C) 1998 Elsevier Science B.V. C1 Univ Rochester, Inst Opt, Rochester, NY 14627 USA. USAF, Phillips Lab, LIDD, PL, Kirtland AFB, NM 87117 USA. RP Walmsley, IA (reprint author), Univ Rochester, Inst Opt, Rochester, NY 14627 USA. NR 17 TC 0 Z9 1 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0030-4018 J9 OPT COMMUN JI Opt. Commun. PD APR 1 PY 1998 VL 149 IS 1-3 BP 61 EP 63 DI 10.1016/S0030-4018(97)00694-9 PG 3 WC Optics SC Optics GA ZR862 UT WOS:000074022200011 ER PT J AU Lasocki, DL Matson, CL Collins, PJ AF Lasocki, DL Matson, CL Collins, PJ TI Analysis of forward scattering of diffuse photon-density waves in turbid media: a diffraction tomography approach to an analytic solution SO OPTICS LETTERS LA English DT Article AB We present a model of the forward problem for diffuse photon-density waves in a turbid medium containing a spherical inhomogeneity, using diffraction tomographic (DT) methods. Recently, by use of DT methods, the forward problem was investigated [Opt. Express 1, 6 (1997); www.osa.org] assuming weak perturbations from the background medium but an arbitrary inhomogeneity structure. We apply DT concepts to a forward problem solution that permits strong perturbations but requires a spherical inhomogeneity. We show that this model is consistent with previous DT results and discuss the application of this new model. C1 USAF, Inst Technol, Dept Elect & Comp Engn, Wright Patterson AFB, OH 45433 USA. USAF, Res Lab, Adv Opt & Imaging Div, Kirtland AFB, NM 87117 USA. RP Lasocki, DL (reprint author), USAF, Inst Technol, Dept Elect & Comp Engn, Wright Patterson AFB, OH 45433 USA. NR 10 TC 6 Z9 6 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD APR 1 PY 1998 VL 23 IS 7 BP 558 EP 560 DI 10.1364/OL.23.000558 PG 3 WC Optics SC Optics GA ZF079 UT WOS:000072860500026 PM 18084576 ER PT J AU Hermesch, CB Hilton, TJ Biesbrock, AR Baker, RA Cain-Hamlin, J McClanahan, SF Gerlach, RW AF Hermesch, CB Hilton, TJ Biesbrock, AR Baker, RA Cain-Hamlin, J McClanahan, SF Gerlach, RW TI Perioperative use of 0.12% chlorhexidine gluconate for the prevention of alveolar osteitis - Efficacy and risk factor analysis SO ORAL SURGERY ORAL MEDICINE ORAL PATHOLOGY ORAL RADIOLOGY AND ENDODONTICS LA English DT Article ID MANDIBULAR 3RD MOLARS; SURGICAL REMOVAL; DRY SOCKET; SICCA-DOLOROSA; DOUBLE-BLIND; ORAL USE; SURGERY; RINSE; COMPLICATIONS; TETRACYCLINE AB Objectives. The purposes of this study were to evaluate the use of 0.12% chlorhexidine gluconate as a prophylactic therapy for the prevention of alveolar osteitis and to further examine subject-based risk factors associated with alveolar osteitis. Design. The trial was a randomized, double-blind, placebo-controlled, parallel-group study conducted among 279 subjects, each of whom required oral surgery for the removal of a minimum of one impacted mandibular third molar. Subjects were instructed to rinse twice daily with 15 ml of chlorhexidine or placebo mouthrinse for 30 seconds for 1 week before and 1 week after the surgical extractions. This regimen included a supervised presurgical rinse. Alveolar osteitis diagnosis was based on the subjective finding-of increasing postoperative pain at the surgical site that was not relieved with mild analgesics, supported by clinical evidence of one or more of the following: loss of blood clot, necrosis of blood clot, and exposed alveolar bone. Results. In comparison with use of the placebo mouthrinse, prophylactic use of the chlorhexidine mouthrinse resulted in statistically significant (p < 0.05) reductions in the incidence of alveolar osteitis. With chlorhexidine therapy, the subject-and extraction-based incidences of alveolar osteitis in the evaluable subset(271 subjects) were reduced, relative to placebo, by 38% and 44%, respectively. The corresponding odds ratios that describe the increased odds of experiencing alveolar osteitis in the placebo group were 1.87 and 2.05 for subject-and extraction-based analyses, respectively. In comparison with nonuse of oral contraceptives, the use of oral contraceptives in female subjects was related to a statistically significant increase in the incidence of alveolar osteitis (odds ratio = 1.92, p = 0.035). Relative to male subjects, the observed incidence of alveolar osteitis for female subjects not using oral contraceptives was not statistically significant (odds ratio = 1.18, p = 0.64). Smoking did not increase the incidence of alveolar osteitis relative to not smoking (odds ratio = 1.20, p = 0.33). Conclusions. These data confirm that the prophylactic use of 0.12% chlorhexidine gluconate mouthrinse results in a significant reduction in the incidence of alveolar osteitis after the extraction of impacted mandibular third molars. In addition, oral contraceptive use in females was confirmed to be a risk factor for the development of alveolar osteitis. C1 Procter & Gamble Co, Hlth Care Res Ctr, Cincinnati, OH 45040 USA. Univ Texas, Hlth Sci Ctr, Dept Gen Dent, San Antonio, TX USA. Armstrong Lab, USAF, Dental Invest Serv, Brooks AFB, TX 78235 USA. Wilford Hall USAF Med Ctr, Dept Gen Dent, San Antonio, TX 78236 USA. RP Biesbrock, AR (reprint author), Procter & Gamble Co, Hlth Care Res Ctr, Cincinnati, OH 45040 USA. NR 42 TC 51 Z9 54 U1 0 U2 5 PU MOSBY-YEAR BOOK INC PI ST LOUIS PA 11830 WESTLINE INDUSTRIAL DR, ST LOUIS, MO 63146-3318 USA SN 1079-2104 J9 ORAL SURG ORAL MED O JI Oral Surg. Oral Med. Oral Pathol. Oral Radiol. Endod. PD APR PY 1998 VL 85 IS 4 BP 381 EP 387 DI 10.1016/S1079-2104(98)90061-0 PG 7 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA ZG931 UT WOS:000073054400011 PM 9574945 ER PT J AU Tjelmeland, EM Moore, WS Hermesch, CB Buikema, DJ AF Tjelmeland, EM Moore, WS Hermesch, CB Buikema, DJ TI A perceptibility curve comparison of Ultra-speed and Ektaspeed Plus Films SO ORAL SURGERY ORAL MEDICINE ORAL PATHOLOGY ORAL RADIOLOGY AND ENDODONTICS LA English DT Article ID X-RAY-FILMS; DENTAL FILMS AB Objective. The purpose of this study was to evaluate the subjectively assessed contrast difference between Kodak's Ultra-speed and Ektaspeed Plus dental radiography films (Eastman Kodak, Rochester, N.Y.) through the use of perceptibility curves. Design. Four series of 22 radiographs were exposed at 70 and 90 kVp with each film type by means of a Gender 1000 dental radiography unit (Gender Corp., Milwaukee, Wis.) for times ranging from 0.05 to 5 seconds at 10 ma. The test object consisted of a 7-mm-thick rectangular aluminum block with 10 circular depth cuts, each 2 mm in diameter, which creaked wells varying in depth from 50 to 500 microns. The corresponding films were processed concurrently (for 4.5 minutes) in total darkness with fresh Kodak Readymatic solutions (Eastman Kodak) held at a constant temperature of 28 degrees C. The resulting radiographs were viewed in a predetermined random order under ideal conditions by 10 dentists. The evaluators recorded the maximum number of perceptible images on each film. A pair of perceptibility curves were generated at 70 and 90 kVp by plotting the log relative exposure versus the mean number of perceptible images. Results. There was no statistical difference between the two film types with respect to the mean number of perceptible images, as analyzed by Wilcoxon's signed rank test (p = 0.22; p = 0.44). Conclusions. There is no subjectively assessed contrast difference between Kodak's Ultra-speed and Ektaspeed Plus films at 70 and 90 kVp. C1 USAF Acad, Wilford Hall USAF Med Ctr, Dept Gen Dent, Colorado Springs, CO 80840 USA. RP Tjelmeland, EM (reprint author), USAF Acad, Wilford Hall USAF Med Ctr, Dept Gen Dent, 2348 Sijan Dr,Suite 2A41, Colorado Springs, CO 80840 USA. NR 24 TC 8 Z9 8 U1 0 U2 0 PU MOSBY-YEAR BOOK INC PI ST LOUIS PA 11830 WESTLINE INDUSTRIAL DR, ST LOUIS, MO 63146-3318 USA SN 1079-2104 J9 ORAL SURG ORAL MED O JI Oral Surg. Oral Med. Oral Pathol. Oral Radiol. Endod. PD APR PY 1998 VL 85 IS 4 BP 485 EP 488 DI 10.1016/S1079-2104(98)90079-8 PG 4 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA ZG931 UT WOS:000073054400029 PM 9574962 ER PT J AU Murphy, KR AF Murphy, KR TI Computer-based patient education SO OTOLARYNGOLOGIC CLINICS OF NORTH AMERICA LA English DT Article AB The computer can be a powerful ally in clinicians efforts to empower their patients to make the right individual decisions. The Internet, in particular, is an extremely valuable resource that enables patients to quickly obtain the latest information on support groups, therapeutic modalities, late-breaking research, and individual coping strategies. The technology is now mature enough that every provider should consider incorporating some type of computer-based patient education into his or her practice. C1 USAF Acad Hosp, USAFA, Ctr Excellence Med Multimedia, USAF Acad, CO 80840 USA. RP Murphy, KR (reprint author), 715 Winding Hills Rd, Monument, CO 80132 USA. NR 0 TC 5 Z9 6 U1 0 U2 0 PU W B SAUNDERS CO PI PHILADELPHIA PA INDEPENDENCE SQUARE WEST CURTIS CENTER, STE 300, PHILADELPHIA, PA 19106-3399 USA SN 0030-6665 J9 OTOLARYNG CLIN N AM JI Otolaryngol. Clin. N. Am. PD APR PY 1998 VL 31 IS 2 BP 309 EP + DI 10.1016/S0030-6665(05)70050-5 PG 11 WC Otorhinolaryngology SC Otorhinolaryngology GA ZL998 UT WOS:000073494600007 PM 9518439 ER PT J AU Green, DM Klink, B AF Green, DM Klink, B TI Platelet gel as an intraoperatively procured platelet-based alternative to fibrin glue SO PLASTIC AND RECONSTRUCTIVE SURGERY LA English DT Letter ID GROWTH-FACTORS C1 David Grant Med Ctr, Anesthesia Serv, Travis AFB, CA 94535 USA. RP Green, DM (reprint author), David Grant Med Ctr, Anesthesia Serv, 101 Bodin Circle,60 MG SGOSA, Travis AFB, CA 94535 USA. NR 11 TC 19 Z9 21 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 USA SN 0032-1052 J9 PLAST RECONSTR SURG JI Plast. Reconstr. Surg. PD APR PY 1998 VL 101 IS 4 BP 1161 EP 1162 DI 10.1097/00006534-199804040-00067 PG 2 WC Surgery SC Surgery GA ZB599 UT WOS:000072488700064 PM 9514368 ER PT J AU Brown, EA Shelley, ML Fisher, JW AF Brown, EA Shelley, ML Fisher, JW TI A pharmacokinetic study of occupational and environmental benzene exposure with regard to gender SO RISK ANALYSIS LA English DT Article; Proceedings Paper CT Conference on Innovative Market-Based Approaches to Environmental Policy - Implementing the Major-Accident Provisions of the Clean Air Act Amendments CY OCT 13-14, 1995 CL UNIV PENN, PHILADELPHIA, PENNSYLVANIA HO UNIV PENN DE benzene; physiologically-based pharmacokinetic modeling; gender differences ID PARTITION-COEFFICIENTS; CHEMICALS; LEUKEMIA; TOLUENE; MODEL; RATS AB Using physiologically-based pharmacokinetic (PBPK) modeling, occupational, personal, and environmental benzene exposure scenarios are simulated for adult men and women. This research identifies differences in internal exposure due to physiological and biochemical gender differences. Physiological and chemical-specific model parameters were obtained from other studies reported in the literature and medical texts for the subjects of interest. Women were found to have a higher blood/air partition coefficient and maximum velocity of metabolism for benzene than men (the two most sensitive parameters affecting gender-specific differences). Additionally, women generally have a higher body fat percentage than men. These factors influence the internal exposure incurred by the subjects and should be considered when conducting a risk assessment. Results demonstrated that physicochemical gender differences result in women metabolizing 23-26% more benzene than men when subject to the same exposure scenario even though benzene blood concentration levels are generally higher in men. These results suggest that women may be at significantly higher risk for certain effects of benzene exposure. Thus, exposure standards based on data from male subjects may not be protective for the female population. C1 USAF, Inst Technol, Wright Patterson AFB, OH 45433 USA. Armstrong Lab, Div Toxicol, Wright Patterson AFB, OH USA. RP Brown, EA (reprint author), USAF, Inst Technol, Wright Patterson AFB, OH 45433 USA. NR 19 TC 34 Z9 34 U1 0 U2 1 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0272-4332 J9 RISK ANAL JI Risk Anal. PD APR PY 1998 VL 18 IS 2 BP 205 EP 213 DI 10.1111/j.1539-6924.1998.tb00932.x PG 9 WC Public, Environmental & Occupational Health; Mathematics, Interdisciplinary Applications; Social Sciences, Mathematical Methods SC Public, Environmental & Occupational Health; Mathematics; Mathematical Methods In Social Sciences GA ZU646 UT WOS:000074218900010 PM 9637076 ER PT J AU Prestidge, BR AF Prestidge, BR TI Radioisotopic implantation for carcinoma of the prostate: Does it work better than it used to? SO SEMINARS IN RADIATION ONCOLOGY LA English DT Article ID PELVIC LYMPHADENECTOMY; I-125 IMPLANTATION; PERMANENT IMPLANTS; CANCER; BIOPSY; BRACHYTHERAPY; RADIOTHERAPY; IRRADIATION; MANAGEMENT C1 Wilford Hall USAF Med Ctr, Dept Radiat Oncol, Lackland AFB, TX 78236 USA. RP Prestidge, BR (reprint author), Wilford Hall USAF Med Ctr, Dept Radiat Oncol, 2200 Bergquist Dr,Suite 1, Lackland AFB, TX 78236 USA. NR 46 TC 23 Z9 23 U1 0 U2 0 PU W B SAUNDERS CO PI PHILADELPHIA PA INDEPENDENCE SQUARE WEST CURTIS CENTER, STE 300, PHILADELPHIA, PA 19106-3399 USA SN 1053-4296 J9 SEMIN RADIAT ONCOL JI Semin. Radiat. Oncol. PD APR PY 1998 VL 8 IS 2 BP 124 EP 131 DI 10.1016/S1053-4296(98)80008-8 PG 8 WC Oncology; Radiology, Nuclear Medicine & Medical Imaging SC Oncology; Radiology, Nuclear Medicine & Medical Imaging GA ZF906 UT WOS:000072945100008 PM 9516593 ER PT J AU Agrons, GA Harty, MP AF Agrons, GA Harty, MP TI Lung disease in premature neonates: Impact of new treatments and technologies SO SEMINARS IN ROENTGENOLOGY LA English DT Article ID RESPIRATORY-DISTRESS SYNDROME; SURFACTANT-REPLACEMENT THERAPY; EXTRACORPOREAL MEMBRANE-OXYGENATION; FREQUENCY JET VENTILATION; PLACEBO-CONTROLLED TRIAL; LYMPHATIC AIR-EMBOLISM; BIRTH-WEIGHT INFANTS; BRONCHOPULMONARY DYSPLASIA; LIQUID VENTILATION; RADIOGRAPHIC FINDINGS C1 Penn Hosp, Dept Radiol, Philadelphia, PA 19107 USA. USAF, Inst Pathol, Dept Radiol Pathol, Washington, DC 20330 USA. Childrens Hosp, Dept Radiol, Philadelphia, PA 19104 USA. RP Agrons, GA (reprint author), Penn Hosp, Dept Radiol, 800 Spruce St, Philadelphia, PA 19107 USA. NR 72 TC 1 Z9 2 U1 0 U2 1 PU W B SAUNDERS CO PI PHILADELPHIA PA INDEPENDENCE SQUARE WEST CURTIS CENTER, STE 300, PHILADELPHIA, PA 19106-3399 USA SN 0037-198X J9 SEMIN ROENTGENOL JI Semin. Roentgenology PD APR PY 1998 VL 33 IS 2 BP 101 EP 116 DI 10.1016/S0037-198X(98)80015-1 PG 16 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA ZK689 UT WOS:000073351300004 PM 9583106 ER PT J AU Reid, JR Bright, VM Butler, JT AF Reid, JR Bright, VM Butler, JT TI Automated assembly of flip-up micromirrors SO SENSORS AND ACTUATORS A-PHYSICAL LA English DT Article; Proceedings Paper CT 9th International Conference on Solid-State Sensors and Actuators CY JUN 16-19, 1997 CL CHICAGO, ILLINOIS SP IEEE Electron Devices Soc DE automated assembly; microactuators; flip-up micromirrors; MEMS; CMOS drive; micro-optics AB Batch fabrication of microelectromechanical systems utilizing flip-up microstructures is limited by the manual assembly process required to lift the structures off the substrate. This problem is solved with the use of an automated assembly system integrated on the die with the flip-up structures. A microelectromechanical automated assembly system consisting of a vertical thermal actuator, a linear assembly micromotor, and a self-engaging locking mechanism is presented in this paper. The vertical thermal actuator is used to lift one end of the plate off the substrate. This provides the linear assembly micromotor with the leverage needed to push the plate up into a position where the self-engaging locking mechanism secures the plate. A CMOS drive system has been developed to control the automated assembly system. When combined with the automated assembly system, CMOS control allows flip-up microstructures to be assembled without any operator intervention. The automated assembly system is demonstrated with a scanning micromirror and a corner cube reflector. (C) 1998 Elsevier Science S.A. All rights reserved. C1 AFRL, SNHA, Bedford, MA 01731 USA. Univ Colorado, Boulder, CO 80309 USA. USAF, Inst Technol, Wright Patterson AFB, OH 45433 USA. RP Reid, JR (reprint author), AFRL, SNHA, 31 Grenier St, Bedford, MA 01731 USA. EM jreid@maxwell.rl.plh.af.mil NR 14 TC 49 Z9 50 U1 0 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0924-4247 J9 SENSOR ACTUAT A-PHYS JI Sens. Actuator A-Phys. PD APR 1 PY 1998 VL 66 IS 1-3 BP 292 EP 298 DI 10.1016/S0924-4247(97)01719-6 PG 7 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA ZJ338 UT WOS:000073204000046 ER PT J AU Abrahamian, GA Polhamus, CCD Muskat, P Karulf, RE AF Abrahamian, GA Polhamus, CCD Muskat, P Karulf, RE TI Diaphragm-like strictures of the ileum associated with NSAID use: A rare complication SO SOUTHERN MEDICAL JOURNAL LA English DT Article ID NONSTEROIDAL ANTIINFLAMMATORY DRUGS; ANTI-INFLAMMATORY DRUGS; COLONIC STRICTURES; SMALL-INTESTINE; DISEASE AB Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely prescribed for many conditions including arthritis. A rare complication of their use is diaphragm-like strictures of the small and large intestines. A 65-year-old woman with a 12-year history of arthritis came to us with a 35-pound weight loss and anorexia. She had been taking piroxicam for 3 years. Evaluation including enteroclysis revealed multiple mid-heal diaphragm-like strictures and proximal small bowel dilatation. The symptoms persisted despite discontinuance of the drug. Abdominal exploration with intraoperative enteroscopy revealed five heal strictures within a short segment of bowel. Resection was done and completion enteroscopy showed no other strictures. The patient recovered uneventfully and had full resolution of the symptoms. We discuss the difficulties in diagnosis and management of this drug complication and briefly review the literature. C1 Wilford Hall USAF Med Ctr, Dept Surg, Lackland AFB, TX 78236 USA. Wilford Hall USAF Med Ctr, Dept Gastroenterol, Lackland AFB, TX 78236 USA. RP Abrahamian, GA (reprint author), 17 Irving St,5, Boston, MA 02114 USA. NR 9 TC 10 Z9 10 U1 0 U2 0 PU SOUTHERN MEDICAL ASSN PI BIRMINGHAM PA 35 LAKESHORE DR PO BOX 190088, BIRMINGHAM, AL 35219 USA SN 0038-4348 J9 SOUTHERN MED J JI South.Med.J. PD APR PY 1998 VL 91 IS 4 BP 395 EP 397 DI 10.1097/00007611-199804000-00018 PG 3 WC Medicine, General & Internal SC General & Internal Medicine GA 170AD UT WOS:000078782200018 PM 9563437 ER PT J AU Hedrick, A AF Hedrick, A TI Resistance training with older populations: Justifications, benefits, protocol SO STRENGTH AND CONDITIONING LA English DT Article ID SKELETAL-MUSCLE; STRENGTH; HYPERTROPHY; ENDURANCE; AGE; MEN C1 USAF Acad, Colorado Springs, CO 80840 USA. RP Hedrick, A (reprint author), USAF Acad, Colorado Springs, CO 80840 USA. NR 25 TC 1 Z9 1 U1 0 U2 0 PU HUMAN KINETICS PUBL INC PI CHAMPAIGN PA 1607 N MARKET ST, CHAMPAIGN, IL 61820-2200 USA SN 1073-6840 J9 STRENGTH COND JI Strength Cond. PD APR PY 1998 VL 20 IS 2 BP 32 EP 39 DI 10.1519/1073-6840(1998)020<0032:RTWOPJ>2.3.CO;2 PG 8 WC Sport Sciences SC Sport Sciences GA ZG545 UT WOS:000073014400008 ER PT J AU Miller, TE Golemboski, KA Ha, RS Bunn, T Sanders, FS Dietert, RR AF Miller, TE Golemboski, KA Ha, RS Bunn, T Sanders, FS Dietert, RR TI Developmental exposure to lead causes persistent immunotoxicity in Fischer 344 rats SO TOXICOLOGICAL SCIENCES LA English DT Article ID TUMOR-NECROSIS-FACTOR; IMMUNE FUNCTION; CYTO-TOXICITY; GROWTH; ASSAY; CELLS; DIFFERENTIATION; INTERLEUKIN-2; PROLIFERATION; EXPRESSION AB Lead has been shown to exert toxic effects during early development. In these in vivo and ex vivo experiments, the effect of lead on the immune system of the developing embryo was assessed. Nine-week-old female Fischer 344 rats were exposed to lead acetate (0, 100, 250, and 500 ppm lead) in their drinking water during breeding and pregnancy (exposure was discontinued at parturition), Offspring received no additional lead treatment after birth. Immune function was assessed in female offspring at 13 weeks of age. Dams in lead-exposed groups were not different from controls with respect to the immune endpoints used in these experiments; however, in the offspring, lead modulated important immune parameters at modest exposure levels. Macrophage cytokine and effector function properties (tumor necrosis factor-alpha and nitric oxide production) were elevated in the 250 ppm group, while cell-mediated immune function was depressed, as shown by a decrease in delayed-type hypersensitivity reactions in the 250 ppm group. Interferon-gamma levels were decreased in the 500 ppm treatment group. Serum levels of IgE were increased in rats exposed to 100 ppm lead. These results indicate that exposure of mothers to moderate levels of lead produces chronic immune modulation in their F344 rat offspring exposed in utero, Since the mothers were not susceptible to chronic immune alterations, a developmental bias to the immunotoxic effects of lead is indicated, The differences observed are consistent with the possibility that lead may bias T helper subset development and/or function, resulting in alterations in the balance among type 1 and type 2 immune responses, (C) 1998 Society of Toxicology. C1 Cornell Univ, Coll Vet Med, Dept Microbiol & Immunol, Ithaca, NY 14853 USA. Cornell Univ, Inst Comparat & Environm Toxicol, Ithaca, NY 14853 USA. RP Miller, TE (reprint author), AL-OET Bldg 79,2856 G St, Wright Patterson AFB, OH 45433 USA. FU NIEHS NIH HHS [ES05950] NR 50 TC 101 Z9 107 U1 0 U2 0 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 1096-6080 J9 TOXICOL SCI JI Toxicol. Sci. PD APR PY 1998 VL 42 IS 2 BP 129 EP 135 DI 10.1006/toxs.1998.2424 PG 7 WC Toxicology SC Toxicology GA ZM173 UT WOS:000073512000007 PM 9579025 ER PT J AU Allerton, J Seay, T Optenberg, S Coltman, CA Higgins, B Thompson, I Lovato, L AF Allerton, J Seay, T Optenberg, S Coltman, CA Higgins, B Thompson, I Lovato, L TI Army and air force leadership in the prostate cancer prevention trial SO UROLOGY LA English DT Article; Proceedings Paper CT Meeting on the Evaluation and Management of the Adult Male with Lower Urinary Tract Symptoms CY JUN 05-08, 1997 CL AMELIA ISLAND, FLORIDA SP Merck & Co Inc, West Point, Pennsylvania ID CARCINOMA; HYPERPLASIA; ANTIGEN AB Prostate cancer is now the most common solid tumor in men in the United States. Although the current public health approach to this disease is early diagnosis and treatment, investigations are also focusing on the possibility of disease prevention. The Prostate Cancer Prevention Trial, begun in 1993, has completed recruitment of 18,000 men who will be randomized to receive either finasteride or placebo to determine if finasteride can prevent the development of this disease. Both Army and Air Force institutions are participating in this trial, with four Department of Defense institutions contributing over 10% of the patients randomized. The results of this study may have a major impact on active duty personnel for whom prevention of prostate cancer may become possible. (C) 1998, Elsevier Science Inc. All rights reserved. C1 Wilford Hall USAF Med Ctr, Dept Hematol Oncol, San Antonio, TX 78236 USA. Wilford Hall USAF Med Ctr, Dept Urol Surg, San Antonio, TX 78236 USA. Brooke Army Med Ctr, Dept Surg, San Antonio, TX USA. SW Oncol Grp, Operat Off, San Antonio, TX 78229 USA. USA, Med Dept Ctr & Sch, Ctr Healthcare Educ & Studies, San Antonio, TX USA. Fred Hutchinson Canc Res Ctr, Seattle, WA 98104 USA. RP Allerton, J (reprint author), 55th MDW MMIH, 2200 Bergquist Dr,Suite 1, Lackland AFB, TX 78236 USA. NR 17 TC 5 Z9 5 U1 0 U2 1 PU CAHNERS PUBL CO PI NEW YORK PA 249 WEST 17 STREET, NEW YORK, NY 10011 USA SN 0090-4295 J9 UROLOGY JI UROLOGY PD APR PY 1998 VL 51 IS 4A SU S BP 64 EP 66 DI 10.1016/S0090-4295(98)00058-2 PG 3 WC Urology & Nephrology SC Urology & Nephrology GA ZK752 UT WOS:000073359000011 PM 9586599 ER PT J AU Faber, PR AF Faber, PR TI Airpower: Theory and practice SO WAR IN HISTORY LA English DT Book Review C1 USAF Acad, USAF Academy, CO 80840 USA. RP Faber, PR (reprint author), USAF Acad, USAF Academy, CO 80840 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU ARNOLD, HODDER HEADLINE PLC PI LONDON PA 338 EUSTON ROAD, LONDON, ENGLAND NW1 3BH SN 0968-3445 J9 WAR HIST JI War Hist. PD APR PY 1998 VL 5 IS 2 BP 249 EP 252 DI 10.1177/096834459800500209 PG 4 WC History; International Relations SC History; International Relations GA ZN326 UT WOS:000073634700009 ER PT J AU Subramanian, PR Krishnamurthy, S Keller, ST Mendiratta, MG AF Subramanian, PR Krishnamurthy, S Keller, ST Mendiratta, MG TI Processing of continuously reinforced Ti-alloy metal matrix composites (MMC) by magnetron sputtering SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article; Proceedings Paper CT Symposium on Advances in Synthesis and Processing of Metal and Ceramic Matrix Composites CY FEB 09-13, 1997 CL ORLANDO, FLORIDA SP ASM Mat Synthesis & Proc Comm, ASM TMS Composite Mat Comm DE Ti-alloy; metal matrix composites; magnetron sputtering ID TITANIUM AB The present work deals with a novel vapor synthesis route, the matrix-coated fiber process, for producing SIC fiber reinforced Ti-6Al-4V and Ti3Al-Nb 'orthorhombic' titanium aluminide composites. In this process, the matrix alloys were directly deposited on SiC fibers by magnetron sputtering. The matrix deposition was conducted both as a batch process, wherein short-length fibers were coated with the matrix material using a planar magnetron sputtering system, as well as a continuous process, in which the matrix was deposited on continuous SiC fibers using a reel-to-reel hollow-cathode magnetron sputtering system. The matrix-coated fibers were consolidated to produce unidirectionally reinforced composite panels, Unreinforced matrix alloy samples were also fabricated using the same sputtering and consolidation conditions. Following heat treatments, the microstructural evolution in these materials were studied. Tensile tests at room temperature were also conducted on matrix and composite specimens. The results indicated that PVD foils and fiber coatings can be heat-treated to obtain microstructures similar to those obtained via conventional processing approaches. Further, the room-temperature tensile properties of PVD foils are comparable to conventionally rolled foils or sheets. (C) 1998 Elsevier Science S.A. All rights reserved. C1 USAF, Res Lab, Mat & Mfg Directorate, MLLM, Wright Patterson AFB, OH 45433 USA. RP Subramanian, PR (reprint author), Universal Energy Syst Inc, Mat & Proc Div, 4401 Dayton Xenia Rd, Dayton, OH 45432 USA. NR 14 TC 20 Z9 30 U1 1 U2 6 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 MAR 31 PY 1998 VL 244 IS 1 BP 1 EP 10 DI 10.1016/S0921-5093(97)00820-4 PG 10 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA ZH404 UT WOS:000073105400002 ER PT J AU Ganguly, BN Bletzinger, P AF Ganguly, BN Bletzinger, P TI Fractional dissociation efficiency measurements of D-2 in a helical resonator D-2-N-2 gas mixture discharge SO APPLIED PHYSICS LETTERS LA English DT Article ID ELECTRON AB Very high fractional dissociation efficiency of D-2 has been measured in an inductive-mode helical resonator discharge In a % D-2-% N-2 gas mixture at 1 Torr pressure. For high N-2 dilution, nearly 100% D-2 dissociation is obtained compared to 13% for pure D-2 at a constant power, The high D-2 dissociation efficiency appears to be achieved through the multiquantum vibrational energy transfer from N-2 to D-2 populating the dissociative D-2 (b (3) Sigma(u)(+)) state at a large internuclear distance. C1 USAF, Res Lab, Wright Patterson AFB, OH 45433 USA. RP Ganguly, BN (reprint author), USAF, Res Lab, Wright Patterson AFB, OH 45433 USA. NR 14 TC 2 Z9 2 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD MAR 30 PY 1998 VL 72 IS 13 BP 1570 EP 1571 DI 10.1063/1.121145 PG 2 WC Physics, Applied SC Physics GA ZE124 UT WOS:000072760100016 ER PT J AU Dewan, EM Picard, RH AF Dewan, EM Picard, RH TI Mesospheric bores SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SOLITARY WAVE; GRAVITY-WAVES; OH AIRGLOW; ATMOSPHERE; EVOLUTION; SOLITONS; DENSITY; MODEL AB A "spectacular gravity wave event" was observed from Haleakala on a four-color all-sky imager, as well as in OH Meinel-band intensity and temperature, on October 10, 1993, during the Airborne Lidar and Observations of Hawaiian Airglow (ALOHA-93) campaign [Taylor et al. 1995]. The event consisted of a sharp frontal passage in airglow brightness propagating at 76 m/s across the field of view and accompanied by small-scale waves behind the front. The purpose of this paper is to propose an explanation for the frontal passage in terms of an internal mesospheric undular bore. Although there have been a number of observations of internal bores in the troposphere and in the ocean, we believe this is the first reported observation of such a bore in the mesosphere. A simple two-layer model, constructed by analogy with the theory of bores in river channels, explains the observations quantitatively. Several predictions are advanced which could serve to test the model. C1 USAF, Res Lab, Space Vehicles Directorate, Hanscom AFB, MA 01731 USA. RP Dewan, EM (reprint author), USAF, Res Lab, Space Vehicles Directorate, 29 Randolph Rd, Hanscom AFB, MA 01731 USA. EM edewan@pldac.plh.af.mil; picard@plh.af.mil NR 30 TC 58 Z9 58 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 MAR 27 PY 1998 VL 103 IS D6 BP 6295 EP 6305 DI 10.1029/97JD02498 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZD911 UT WOS:000072737800033 ER PT J AU Sheriff, DD Augustyniak, RA O'Leary, DS AF Sheriff, DD Augustyniak, RA O'Leary, DS TI Muscle metaboreflex induced increases in central venous pressure. SO FASEB JOURNAL LA English DT Meeting Abstract C1 USAF, Res Lab, Brooks AFB, TX 78235 USA. Wayne State Univ, Sch Med, Dept Physiol, Detroit, MI 48201 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0892-6638 J9 FASEB J JI Faseb J. PD MAR 20 PY 1998 VL 12 IS 5 SU S MA 4010 BP A691 EP A691 PN 2 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA 121HD UT WOS:000076006500392 ER PT J AU Adair, ER Cobb, BL Mylacraine, KS AF Adair, ER Cobb, BL Mylacraine, KS TI Physiological responses of human volunteers during whole-body RF exposure at 2450 MHz. SO FASEB JOURNAL LA English DT Meeting Abstract C1 USAF, Res Lab, HEDR, Brooks AFB, TX 78235 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0892-6638 J9 FASEB J JI Faseb J. PD MAR 17 PY 1998 VL 12 IS 4 SU S MA 320 BP A55 EP A55 PN 1 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA 121HC UT WOS:000076006400319 ER PT J AU Chornuk, MA Bernard, SL Burns, JW Glenny, RW Sherif, DD Sinclair, SE Hlastala, MP AF Chornuk, MA Bernard, SL Burns, JW Glenny, RW Sherif, DD Sinclair, SE Hlastala, MP TI Effects of +G(z) and positive pressure breathing on pulmonary blood flow (PBF) heterogeneity. SO FASEB JOURNAL LA English DT Meeting Abstract C1 Univ Washington, Seattle, WA 98195 USA. Armstrong Lab, Brooks AFB, San Antonio, TX 78240 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0892-6638 J9 FASEB J JI Faseb J. PD MAR 17 PY 1998 VL 12 IS 4 SU S MA 2904 BP A499 EP A499 PN 1 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA 121HC UT WOS:000076006402897 ER PT J AU Walters, TJ Ryan, KL Tate, LM Mason, PA AF Walters, TJ Ryan, KL Tate, LM Mason, PA TI The influence of brain and core temperature on endurance performance. SO FASEB JOURNAL LA English DT Meeting Abstract C1 Veridian Inc, San Antonio, TX 78235 USA. Trinity Univ, Dept Biol, San Antonio, TX 78235 USA. USAF, Res Lab, San Antonio, TX 78235 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0892-6638 J9 FASEB J JI Faseb J. PD MAR 17 PY 1998 VL 12 IS 4 SU S MA 316 BP A54 EP A54 PN 1 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA 121HC UT WOS:000076006400314 ER PT J AU Buchholz, TA Walden, TL Prestidge, BR AF Buchholz, TA Walden, TL Prestidge, BR TI Cost-effectiveness of posttreatment surveillance after radiation therapy for early stage seminoma SO CANCER LA English DT Article DE seminoma; radiation; cost; surveillance; patterns of failure ID II TESTICULAR SEMINOMA; TESTIS; RADIOTHERAPY; IRRADIATION; PATTERNS; EXPERIENCE; METASTASES; FAILURE; TUMORS AB BACKGROUND. This study evaluated the cost-effectiveness of posttreatment surveillance after radiation therapy for early stage seminoma. METHODS. From 1988-1995, 47 patients with Stage I, and 11 patients with Stage II seminoma (based on the Royal Marsden staging system) received paraaortic and pelvic lymph node radiation after radical orchiectomy. Patient records were reviewed and patients surveyed to determine the tests ordered for posttreatment surveillance. RESULTS. With a median follow-up of 55 months, there were 2 recurrences among the 58 patients. Eight-year actuarial disease free survival was 93%, with 100% overall survival. Information concerning follow-up screening was available for 56 patients. The follow-up tests ordered Included 842 physical examinations, 815 chest X-rays, 839 serum markers, 250 computerized tomography scans, and 112 abdominal plain films. The total cost of these examinations according to 1996 private sector charges and 1996 Medicare reimbursement rates, respectively, was $602,673.01 (average $10,762.02 per patient) and $282,746.52 (average $5049.05 per patient). The two patients who experienced recurrence were diagnosed independently of their posttreatment screening program. One patient recurred 7.5 months after his original diagnosis with an isolated spinal cord compression. The second patient had a mediastinum recurrence > 6 years after treatment. At last follow-up, both patients were disease free after salvage treatment. CONCLUSIONS, Patients with early stage seminoma treated with orchiectomy and radiation have excellent disease free survival rates. The cost of the surveillance program studied does not appear to be justifiable. (C) 1998 American Cancer Society. C1 Univ Texas, Md Anderson Canc Ctr, Dept Radiat Oncol, Houston, TX 77030 USA. Natl Canc Inst, Radiat Oncol Branch, Bethesda, MD USA. Wilford Hall USAF Med Ctr, Div Radiat Oncol, Lackland AFB, TX 78236 USA. RP Buchholz, TA (reprint author), Univ Texas, Md Anderson Canc Ctr, Dept Radiat Oncol, Box 97,1515 Holcombe Blvd, Houston, TX 77030 USA. NR 18 TC 16 Z9 16 U1 0 U2 0 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0008-543X J9 CANCER-AM CANCER SOC JI Cancer PD MAR 15 PY 1998 VL 82 IS 6 BP 1126 EP 1133 DI 10.1002/(SICI)1097-0142(19980315)82:6<1126::AID-CNCR17>3.0.CO;2-8 PG 8 WC Oncology SC Oncology GA ZA556 UT WOS:000072376400017 PM 9506359 ER PT J AU Fridman, SV Berkey, FT AF Fridman, SV Berkey, FT TI Utilization of sky-wave backscatter sounders for real-time monitoring of ionospheric structure over extended geographic regions SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article AB Backscatter ionograms (BI) and quasi vertical incidence (QVI) ionograms are routinely collected at over-the-horizon radar (OTHR) installations operated by the U.S. Navy. The BI provides information about the downrange ionosphere up to several thousand km from the sounder. In this paper, a method for the quantitative extraction of this information by means of a leading edge inversion technique is described and applied to data acquired by the BI sounder operating at the Chesapeake, VA OTHR facility. Because this sounder is used to sample 8 azimuthal sectors, maps of plasma frequency at a constant altitude can be derived over a geographic region that covers a 64 degrees angular sector out to distances of similar to 2000 km. The unique capability of the OTHR BI sounders to provide realtime monitoring of the ionosphere over a large geographical area is demonstrated. C1 Mission Res Corp, Monterey, CA 93940 USA. Utah State Univ, Space Dynam Lab, Logan, UT 84322 USA. USAF, Res Lab, Rome, NY 13441 USA. RP Fridman, SV (reprint author), Mission Res Corp, 10 Ragsdale Dr,Suite 201, Monterey, CA 93940 USA. NR 12 TC 2 Z9 2 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD MAR 15 PY 1998 VL 25 IS 6 BP 885 EP 888 DI 10.1029/98GL00428 PG 4 WC Geosciences, Multidisciplinary SC Geology GA ZD051 UT WOS:000072645900032 ER PT J AU Cliver, EW Boriakoff, V Bounar, KH AF Cliver, EW Boriakoff, V Bounar, KH TI Geomagnetic activity and the solar wind during the Maunder Minimum SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID PAST 500 YEARS; MAGNETIC ACTIVITY; SUNSPOT NUMBER; RADIOCARBON; CYCLE; AA AB We used a strong (r = 0.96) correlation between Ii-year averages of sunspot number (SSN) and the geomagnetic aa index to infer that the mean level of geomagnetic activity during the Maunder Minimum (1645-1715) was approximately a third of that observed for recent solar cycles (similar to 7 nT VS. similar to 24 nT). We determined the variation of Ii-year averages of solar wind speed (v) and the southward component of the interplanetary magnetic field (B-s) with cycle-averaged SSN for the two most recent cycles and also compared cycle-averaged variations of v(2)B(s) and aa for the same interval. We then extrapolated these observed solar wind variations to Maunder Minimum conditions (mean SSN of similar to 2 and mean aa value of similar to 7 nT) to deduce that, on average, the solar wind during that period was somewhat slower (v = 340 +/- 50 km s(-1)), and the interplanetary magnetic field much smoother (B-s = 0.3+/-0.1 nT), than at present (similar to 440 km s(-1) and similar to 1.2 nT). Various lines of evidence (including Be-10 data) suggest that, despite the virtual absence of sunspots that characterized the Maunder Minimum, the 11-year geomagnetic (solar wind) cycle persisted throughout this period. C1 USAF, Res Lab, Space Vehicles Directorate, Hanscom AFB, MA 01731 USA. Radex Inc, Bedford, MA USA. RP Cliver, EW (reprint author), USAF, Res Lab, Space Vehicles Directorate, Hanscom AFB, MA 01731 USA. NR 24 TC 49 Z9 49 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD MAR 15 PY 1998 VL 25 IS 6 BP 897 EP 900 DI 10.1029/98GL00500 PG 4 WC Geosciences, Multidisciplinary SC Geology GA ZD051 UT WOS:000072645900035 ER PT J AU Prestidge, BR Bice, WS Kiefer, EJ Prete, JJ AF Prestidge, BR Bice, WS Kiefer, EJ Prete, JJ TI Timing of computed tomography-based postimplant assessment following permanent transperineal prostate brachytherapy SO INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS LA English DT Article DE prostate brachytherapy; postimplant assessment; quality assurance ID RADIATION-THERAPY; IMPLANTATION; CARCINOMA AB Purpose: To establish the rate of resolution of prostatic edema following transperineal interstitial permanent prostate brachytherapy, and to determine the results and impact of timing of the postimplant assessment on the dose-volume relationship. Methods and Materials: A series of 19 consecutive patients with early-stage adenocarcinoma of the prostate receiving transperineal interstitial permanent prostate brachytherapy, mere enrolled in this study. Twelve received I-125 and seven received Pd-103. Postoperative assessment included a computed tomographic (CT) scan on postoperative days 1, 8, 30, 90, and 180. On each occasion, CT scans were performed on a GE helical unit at 3-mm abutting slices, 15-cm field of view. Prostate volumes mere outlined on CT scans by a single clinician. Following digitization of the volumes and radioactive sources, volumes and dose-volume histograms were calculated. The prostate volume encompassed by the 80% and 100% reference isodose volumes was calculated. Results: Preimplant transrectal ultrasound determined volumes varied from 17.5 to 38.6 cc (median 27.9 cc). Prostate volumes previously defined on 40 randomly selected postimplant CT scans were compared in a blinded fashion to a second CT-derived volume and ranged from -32% to +24%. The Pearson correlation coefficient for prostate CT volume reproducibility was 0.77 (p < 0.03). CT scan-determined volume performed on postoperative day 1 was an average of 41.4% greater than the volume determined by preimplant ultrasound. Significant decreases in average volume were seen during the first month postoperatively. Average volume decreased 14% from day 1 to day 8, 10% from day 8 to day 30, 3% from day 30 to day 90, and 2% thereafter. Coverage of the prostate volume by the 80% isodose volume increased from 85.6% on postoperative day 1 to 92.2% on postoperative day 180. The corresponding increase in the 100% reference dose coverage of the prostate volume ranged from 73.1% to 83.3% between postoperative days 1, and 180, respectively. Conclusions: Most of the prostatic edema induced by brachytherapy appears to resolve by postoperative day 30. Scans performed on postimplant day 30 appear to adequately describe the time-averaged dose coverage of the prostate. This suggests that waiting approximately 1 month to perform postimplant analysis gives the most accurate prostatic volume and, consequently, dosimetric description of the implant. (C) 1998 Elsevier Science Inc. C1 Wilford Hall USAF Med Ctr, Dept Radiat Oncol, San Antonio, TX 78236 USA. Univ Texas, Hlth Sci Ctr, Dept Radiol, Div Radiol Sci, San Antonio, TX 78284 USA. RP Prestidge, BR (reprint author), Wilford Hall USAF Med Ctr, 2200 Bergquist Dr Ste 1, Lackland AFB, TX 78236 USA. NR 15 TC 110 Z9 112 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0360-3016 J9 INT J RADIAT ONCOL JI Int. J. Radiat. Oncol. Biol. Phys. PD MAR 15 PY 1998 VL 40 IS 5 BP 1111 EP 1115 DI 10.1016/S0360-3016(97)00947-4 PG 5 WC Oncology; Radiology, Nuclear Medicine & Medical Imaging SC Oncology; Radiology, Nuclear Medicine & Medical Imaging GA ZE194 UT WOS:000072767500013 PM 9539566 ER PT J AU Bice, WS Prestidge, BR Prete, JJ Dubois, DF AF Bice, WS Prestidge, BR Prete, JJ Dubois, DF TI Clinical impact of implementing the recommendations of AAPM task group 43 on permanent prostate brachytherapy using I-125 SO INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS LA English DT Article DE brachytherapy; (125)Iodine; dosimetry; prostate ID IMPLANTATION; DOSIMETRY; CARCINOMA AB Purpose: To determine the clinical impact upon permanent interstitial prostate I-125 brachytherapy after conversion to AAPM Task Group 43 (TG 43) guidelines, Methods: The value of quantities used in the calculation of dose from two institutions, Northwest Tumor Institute (NWTI) and Memorial Sloan-Kettering Cancer Center (MSKCC), which pioneered interstitial techniques for prostate brachytherapy were compared to those recently determined and published by TG 43 of the American Association of Physicists in Medicine (AAPM). Using two different weighting schemes, the change in the commonly prescribed reference dose of 160 Gy was determined and found to be in agreement with that recently suggested. Volumes encompassed by the reference isodose surface mere determined from a single source implant and a regularly distributed implant to show the effect of change in reference dose, A comparative analysis on 10 patients was performed to show how this change affected common implant quality descriptors and the effect of changing the calculation formalism without changing the reference dose, Results: Both weighting schemes suggested a change in reference dose from 160 to 144 Gy. Single-source and distributed-source volumetric analysis confirmed this value, The effect on commonly used conformity and uniformity quantifiers for 10 implant patients was tabulated, Conclusion: Upon adopting the recommendations suggested by TG 43, institutions that perform permanent I-125 prostate implants using calculation methods adapted from the MWTI or MSKCC should revise their treatment prescriptions from 160 to 144 Gy so that the doses delivered to patients remain unaffected, Institutions using other techniques to calculate dose should conduct an analysis similar to the one detailed here. (C) 1998 Elsevier Science Inc. C1 Wilford Hall USAF Med Ctr, Radiat Oncol PSRT, Radiat Oncol Serv, Lackland AFB, TX 78236 USA. Univ Texas, Hlth Sci Ctr, Div Radiol Sci, San Antonio, TX USA. RP Bice, WS (reprint author), Wilford Hall USAF Med Ctr, Radiat Oncol PSRT, Radiat Oncol Serv, 2200 Bergquist Dr,Ste 1, Lackland AFB, TX 78236 USA. NR 16 TC 45 Z9 47 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0360-3016 J9 INT J RADIAT ONCOL JI Int. J. Radiat. Oncol. Biol. Phys. PD MAR 15 PY 1998 VL 40 IS 5 BP 1237 EP 1241 DI 10.1016/S0360-3016(97)00949-8 PG 5 WC Oncology; Radiology, Nuclear Medicine & Medical Imaging SC Oncology; Radiology, Nuclear Medicine & Medical Imaging GA ZE194 UT WOS:000072767500028 PM 9539581 ER PT J AU Twigg, RD Bannon, PR AF Twigg, RD Bannon, PR TI Frontal equilibration by frictional processes SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID GEOSTROPHIC MOMENTUM APPROXIMATION; 2-DIMENSIONAL EADY WAVES; NONLINEAR EQUILIBRATION; FRONTOGENESIS; DYNAMICS; MODEL AB The effect of friction on frontogenesis driven by a stretching deformation field is studied analytically in both a quasigeostrophic and a semigeostrophic framework for a semi-infinite, adiabatic, Boussinesq fluid on an f plane. Friction is incorporated into the: model in tenus of a boundary layer primping term., The solutions demonstrate that the effect of friction is frontolytic. The quasigeostrophic fronts always equilibrate al a finite horizontal scale. The semigeostrophic fronts equilibrate at a finite horizontal scale if the strength of thr frontogenesis is below; a threshold value. Above this threshold. the front is predicted to collapse to a discontinuity in its thermal and momentum fields. C1 Penn State Univ, Dept Meteorol, University Pk, PA 16802 USA. USAF, Directorate Weather, Headquarters, Washington, DC 20330 USA. RP Bannon, PR (reprint author), Penn State Univ, Dept Meteorol, 503 Walker Bldg, University Pk, PA 16802 USA. NR 18 TC 3 Z9 3 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD MAR 15 PY 1998 VL 55 IS 6 BP 1084 EP 1087 DI 10.1175/1520-0469(1998)055<1084:FEBFP>2.0.CO;2 PG 4 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZB373 UT WOS:000072465500012 ER PT J AU Semiatin, SL Seetharaman, V Weiss, I AF Semiatin, SL Seetharaman, V Weiss, I TI Hot workability of titanium and titanium aluminide alloys - an overview SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article; Proceedings Paper CT Conference on Thermomechanical Processing and Metallurgy of Titanium Alloys CY JUL 07-11, 1997 CL UNIV WOLLONGONG, WOLLONGONG, AUSTRALIA SP Asian Off Aerosp Res & Dev, USAF, Off Sci Res HO UNIV WOLLONGONG DE hot workability; Ti-Al alloys; titanium ID TIAL INTERMETALLIC COMPOUND; HIGH-TEMPERATURE DEFORMATION; STRAIN-RATE SENSITIVITY; ELEVATED-TEMPERATURES; MECHANICAL-BEHAVIOR; CAVITY GROWTH; SHEAR BANDS; TI-6AL-2SN-4ZR-2MO-0.1SI; FRACTURE; FAILURE AB The hot workability of conventional titanium alloys and titanium aluminides is reviewed. For both alloy classes, the influence of hot working variables and microstructure on failure via fracture or flow-localization controlled processes is summarized. The occurrence of wedge cracking and cavitation during bulk forming of alpha/beta alloys with Widmanstatten microstructures or gamma titanium aluminides with lamellar or equiaxed structures, is examined. In particular, the effects of grain size, grain boundary second phases and process variables on failure are presented. Observations and models of flow localization and cavitation processes which lead to failure during low strain rate, superplastic, tensile-type deformation of titanium and titanium aluminide alloys with fine equiaxed structures, are also described. In the area of flow-localization-controlled failure during bulk forming, the occurrence of shear bands and other flow nonuniformities during both conventional and isothermal hot working processes is reviewed. The influence of material properties, such as flow softening rate and strain rate sensitivity and process variables, which lead to temperature and hence flow nonuniformities, is examined. The flow localization concepts are illustrated for several hot working processes. (C) 1998 Elsevier Science S.A. All rights reserved. C1 USAF, Res Lab, Mat & Mfg Directorate, AFRL,MLLM, Wright Patterson AFB, OH 45433 USA. Universal Energy Syst Inc, Dayton, OH 45432 USA. Wright State Univ, Dayton, OH 45435 USA. RP Semiatin, SL (reprint author), USAF, Res Lab, Mat & Mfg Directorate, AFRL,MLLM, Bldg 655,Suite 1,2230 10th St, Wright Patterson AFB, OH 45433 USA. EM semiatsl@ml.wpafb.af.mil RI SEMIATIN, SHELDON/E-7264-2017 NR 86 TC 159 Z9 165 U1 10 U2 64 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 MAR 15 PY 1998 VL 243 IS 1-2 BP 1 EP 24 DI 10.1016/S0921-5093(97)00776-4 PG 24 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA ZH762 UT WOS:000073145100002 ER PT J AU Weiss, I Semiatin, SL AF Weiss, I Semiatin, SL TI Thermomechanical processing of beta titanium alloys - an overview SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article; Proceedings Paper CT Conference on Thermomechanical Processing and Metallurgy of Titanium Alloys CY JUL 07-11, 1997 CL UNIV WOLLONGONG, WOLLONGONG, AUSTRALIA SP Asian Off Aerosp Res & Dev, USAF, Off Sci Res HO UNIV WOLLONGONG DE thermomechanical processing; beta titanium alloys ID DEFORMATION AB Thermomechanical processing (TMP) is associated with two major requirements: (i) to produce usable shapes through primary working (ingot breakdown) and secondary mill operations (hot rolling or forging) and (ii) to optimize mechanical properties through microstructure control during the different stages of the thermomechanical process. This paper reviews the thermomechanical processing of beta titanium alloys in general and high temperature deformation mechanisms, microstructure control during TMP, and final mechanical properties in particular. (C) 1998 Elsevier Science S.A. All rights reserved. C1 Wright State Univ, Dept Mech & Mat Engn, Dayton, OH 45435 USA. Wright Lab, Mat Directorate, MLLM, Wright Patterson AFB, OH 45433 USA. RP Weiss, I (reprint author), Wright State Univ, Dept Mech & Mat Engn, Dayton, OH 45435 USA. RI SEMIATIN, SHELDON/E-7264-2017 NR 55 TC 271 Z9 308 U1 11 U2 61 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 MAR 15 PY 1998 VL 243 IS 1-2 BP 46 EP 65 DI 10.1016/S0921-5093(97)00783-1 PG 20 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA ZH762 UT WOS:000073145100005 ER PT J AU Dimiduk, DM Martin, PL Kim, YW AF Dimiduk, DM Martin, PL Kim, YW TI Microstructure development in gamma alloy mill products by thermomechanical processing SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article; Proceedings Paper CT Conference on Thermomechanical Processing and Metallurgy of Titanium Alloys CY JUL 07-11, 1997 CL UNIV WOLLONGONG, WOLLONGONG, AUSTRALIA SP Asian Off Aerosp Res & Dev, USAF, Off Sci Res HO UNIV WOLLONGONG DE gamma titanium aluminides; microstructure development; thermochemical professing ID TITANIUM ALUMINIDE AB Gamma titanium aluminides are emerging as a revolutionary high-temperature material. The last decade led to significant engineering advances and component demonstrations for cast gamma-alloy products. However, cast processing has yet to permit the full potential of these materials to be realized, principally as the result of the limited microstructural control available. Conversely, thermomechanically processed gamma alloys are leading to a wide spectrum of microstructures, an outstanding balance of properties within the alloy class, and prospects for improved alloy durability. The manuscript succinctly describes the general field of thermomechanical processing for gamma alloys, giving particular attention to homogenization of large ingots in wrought processing. Aspects of producing fine-grained fully-lamellar microstructures, having controlled lamellar characteristics in wrought mill products are discussed. Some influences of alloy chemistry are discussed to show the feasibility of producing high-strength alloys across the gamma alloy class. Both a beta-phase forming element (1 at.% Mo) and boron in the alloys are examined as grain-size controlling agents. These alloys are compared along with traditional alloys containing neither of these elements. Thermal-treatment windows are identified and discussed for producing fully-lamellar materials. When grain-size controlling agents such as boron or beta-phase are used, the lamellar transformation kinetics may be significantly altered relative to conventional gamma alloys, thus changing the thermal process path and affecting the perfection of the lamellar microstructures. These lead to concomitant changes in alloy properties. The prospects for attaining such structures and properties in large product scales are discussed. (C) 1998 Elsevier Science S.A. All rights reserved. C1 Wright Lab, Mat Directorate, MLLM, Wright Patterson AFB, OH 45433 USA. Rockwell Int Sci Ctr, Thousand Oaks, CA 91360 USA. Universal Energy Syst Inc, Dayton, OH 45432 USA. RP Dimiduk, DM (reprint author), Wright Lab, Mat Directorate, MLLM, Bldg 655,2230 10th St, Wright Patterson AFB, OH 45433 USA. NR 27 TC 55 Z9 59 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 MAR 15 PY 1998 VL 243 IS 1-2 BP 66 EP 76 DI 10.1016/S0921-5093(97)00780-6 PG 11 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA ZH762 UT WOS:000073145100006 ER PT J AU Krishnamurthy, S Smith, PR Miracle, DB AF Krishnamurthy, S Smith, PR Miracle, DB TI Modification of transverse creep behavior of an orthorhombic titanium aluminide based Ti-22Al-23Nb/SiCf composite using heat treatment SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article; Proceedings Paper CT Conference on Thermomechanical Processing and Metallurgy of Titanium Alloys CY JUL 07-11, 1997 CL UNIV WOLLONGONG, WOLLONGONG, AUSTRALIA SP Asian Off Aerosp Res & Dev, USAF, Off Sci Res HO UNIV WOLLONGONG DE transverse creep behavior; orthorhombic titanium matrix composites; heat treatment ID MATRICES AB The feasibility of improving the transverse creep properties of an orthorhombic titanium aluminide matrix composite reinforced with unidirectional SCS-6 SiC fiber via modification of matrix microstructure was investigated using post-consolidation heat treatments. A Ti-22Al-23Nb/SCS-6 4-ply composite was subjected to heat treatments which consisted of solutionizing at either above or below the beta-transus temperature of the matrix alloy, followed by controlled cooling and aging within the orthorhombic (O) phase field. Mechanical testing showed that the transverse (90 degrees) creep behavior of the titanium alloy composite in the temperature range 650-760 degrees C is significantly improved by a supra-transus solution heat treatment followed by the aging, without any adverse effect on the longitudinal (0 degrees) tensile strength of the composite. This improvement in the creep response was attributed to an increase in the volume fraction of the orthorhombic phase and the lath morphology of the (O + beta) two-phase regions in the matrix microstructure. The effect of sub-transus heat treatment was less pronounced and the transverse creep resistance of the composite decreased with increasing volume fraction of the alpha(2) phase in the matrix. Examination of creep ruptured 90 degrees composite specimens showed that transverse creep damage in the form of fiber/matrix interfacial debonding occurs predominantly at very closely spaced or touching fibers. (C) 1998 Elsevier Science S.A. All rights reserved. C1 Universal Energy Syst Inc, Dayton, OH 45432 USA. USAF, Wright Lab, Mat Directorate, MLLM, Wright Patterson AFB, OH 45433 USA. RP Krishnamurthy, S (reprint author), Universal Energy Syst Inc, 4401 Dayton Xenia Rd, Dayton, OH 45432 USA. EM krishnas@ml.wpafb.af.mil NR 6 TC 11 Z9 12 U1 0 U2 4 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 MAR 15 PY 1998 VL 243 IS 1-2 BP 285 EP 289 DI 10.1016/S0921-5093(97)00815-0 PG 5 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA ZH762 UT WOS:000073145100040 ER PT J AU Sun, G Lu, Y Friedman, L Soref, RA AF Sun, G Lu, Y Friedman, L Soref, RA TI Heavy-hole intersubband scattering by confined optical phonons in a Si/ZnS superlattice SO PHYSICAL REVIEW B LA English DT Article ID QUANTUM-WELL STRUCTURES; CASCADE LASER; SILICON; HETEROSTRUCTURES; SINGLE; GROWTH; LAYERS; ZNS AB The confinement of optical modes of vibration in a superlattice consisting of polar and nonpolar materials is described by a continuum model, Specifically, the structure under investigation is the Si/ZnS superlattice. Optical phonon modes in Si and ZnS layers are totally confined within their respective layers since both layers can be treated as infinitely rigid with respect to the other layer. Since there are no associated electric fields with nonpolar optical phonons in Si layers, only a mechanical boundary condition needs to be satisfied for these nonpolar optical modes at the Si-ZnS interface. The optical phonons in Si layers can be described by guided modes consisting of an uncoupled s-TO mode and a hybrid of LO and p-TO modes with no interface modes. In ZnS layers, a continuum model hybridizing the LO, TO, and IP modes is necessary to satisfy both the mechanical and electrostatic boundary conditions at the heterointerface. A numerical procedure is provided to determine the common frequency between LO, TO, and TP modes. This is a procedure for obtaining the eigenmodes of a mixed polar-nonpolar heterosystem. Analytical expressions are obtained for the ionic displacement and associated electric field as well as scalar and vector potentials. The established model for the confined optical phonons is used in calculating the intersubband heavy-hole scattering rate by optical phonons in the Si/ZnS superlattice. Our results indicate that contributions to the intersubband scattering rate from Si or ZnS confined optical phonons depend strongly on the distribution of envelope wave functions over the respective layers within which different types of optical phonons are confined. C1 Univ Massachusetts, Engn Program, Boston, MA 02125 USA. USAF, Rome Lab, Bedford, MA 01731 USA. RP Sun, G (reprint author), Univ Massachusetts, Engn Program, Boston, MA 02125 USA. NR 30 TC 6 Z9 6 U1 0 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 MAR 15 PY 1998 VL 57 IS 11 BP 6550 EP 6560 DI 10.1103/PhysRevB.57.6550 PG 11 WC Physics, Condensed Matter SC Physics GA ZD807 UT WOS:000072726400058 ER PT J AU Lo, I Chen, SJ Lee, YC Tu, LW Mitchel, WC Ahoujja, M Perrin, RE Tu, RC Su, YK Lan, WH Tu, SL AF Lo, I Chen, SJ Lee, YC Tu, LW Mitchel, WC Ahoujja, M Perrin, RE Tu, RC Su, YK Lan, WH Tu, SL TI Negative persistent photoconductivity in II-VI ZnS1-xSex/Zn1-yCdySe quantum wells SO PHYSICAL REVIEW B LA English DT Article ID ALXGA1-XAS ALLOYS; DX CENTERS; GAAS; HETEROSTRUCTURES; SEMICONDUCTORS; ZN0.3CD0.7SE; RELAXATION; DIFFUSION AB The carrier concentration of a two-dimensional electron gas in a Zn0.2Cd0.9Se quantum well was persistently reduced by red-light illumination at low temperature. The deep-level donors were "frozen out" at 50 K and the thermal activation energy was about 42.6 meV. We believe that these deep-level donors are unlikely DX centers, and the observed negative persistent photoconductivity probably arises from the trapping of electron by the empty localized state of random-local-potential fluctuations in the barrier. C1 Natl Sun Yat Sen Univ, Dept Phys, Kaohsiung 80424, Taiwan. USAF, Wright Lab, Mat Directorate, Wright Patterson AFB, OH 45433 USA. Natl Cheng Kung Univ, Dept Elect Engn, Tainan 70101, Taiwan. Chung Shan Inst Sci & Technol, Tao Yuan, Taiwan. RP Lo, I (reprint author), Natl Sun Yat Sen Univ, Dept Phys, Kaohsiung 80424, Taiwan. NR 27 TC 5 Z9 5 U1 1 U2 4 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 MAR 15 PY 1998 VL 57 IS 12 BP R6819 EP R6822 DI 10.1103/PhysRevB.57.R6819 PG 4 WC Physics, Condensed Matter SC Physics GA ZE126 UT WOS:000072760300014 ER PT J AU Barth, W AF Barth, W TI Low-dose aspirin for preeclampsia - The unresolved question SO NEW ENGLAND JOURNAL OF MEDICINE LA English DT Editorial Material ID PREGNANCY-INDUCED HYPERTENSION C1 Wilford Hall USAF Med Ctr, San Antonio, TX 78236 USA. RP Barth, W (reprint author), Wilford Hall USAF Med Ctr, San Antonio, TX 78236 USA. NR 9 TC 8 Z9 8 U1 0 U2 1 PU MASS MEDICAL SOC PI BOSTON PA 10 SHATTUCK, BOSTON, MA 02115 USA SN 0028-4793 J9 NEW ENGL J MED JI N. Engl. J. Med. PD MAR 12 PY 1998 VL 338 IS 11 BP 756 EP 757 DI 10.1056/NEJM199803123381109 PG 2 WC Medicine, General & Internal SC General & Internal Medicine GA ZB546 UT WOS:000072483400009 PM 9494153 ER PT J AU Alam, MS Bognar, JG Cain, S Yasuda, BJ AF Alam, MS Bognar, JG Cain, S Yasuda, BJ TI Fast registration and reconstruction of aliased low-resolution frames by use of a modified maximum-likelihood approach SO APPLIED OPTICS LA English DT Article ID IMAGE AB During the process of microscanning a controlled vibrating mirror typically is used to produce subpixel shifts in a sequence of forward-looking infrared (FLIR) images. If the FLIR is mounted on a moving platform, such as an aircraft, uncontrolled random vibrations associated with the platform can be used to generate the shifts. Iterative techniques such as the expectation-maximization (EM) approach by means of the maximum-likelihood algorithm can be used to generate high-resolution images from multiple randomly shifted aliased frames. In the maximum-likelihood approach the data are considered to be Poisson random variables and an EM algorithm is developed that iteratively estimates an unaliased image that is compensated for known imager-system blur while it simultaneously estimates the translational shifts. Although this algorithm yields high-resolution images from a sequence of randomly shifted frames, it requires significant computation time and cannot be implemented for real-time applications that use the currently available high-performance processors. The new image shifts are iteratively calculated by evaluation of a cost function that compares the shifted and interlaced data frames with the corresponding values in the algorithm's latest estimate of the high-resolution image. We present a registration algorithm that estimates the shifts in one step. The shift parameters provided by the new algorithm are accurate enough to eliminate the need for iterative recalculation of translational shifts. Using this shift information, we apply a simplified version of the EM algorithm to estimate a high-resolution image hom a given sequence of video frames. The proposed modified EM algorithm has been found to reduce significantly the computational burden when compared with the original EM algorithm, thus making it more attractive for practical implementation. Both simulation and experimental results are presented to verify the effectiveness of the proposed technique. (C) 1998 Optical Society of America. C1 Purdue Univ, Dept Elect Engn, Ft Wayne, IN 46805 USA. Indiana Univ, Grad Fac, Bloomington, IN 47404 USA. Technol Sci Serv Inc, Dayton, OH 45437 USA. Wright Lab, Sensor Technol Branch, WL AAJT, Wright Patterson AFB, Dayton, OH 45433 USA. RP Purdue Univ, Dept Elect Engn, Ft Wayne, IN 46805 USA. NR 19 TC 8 Z9 9 U1 0 U2 1 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD MAR 10 PY 1998 VL 37 IS 8 BP 1319 EP 1328 DI 10.1364/AO.37.001319 PG 10 WC Optics SC Optics GA ZA189 UT WOS:000072337900006 PM 18268719 ER PT J AU Varanasi, C Biggers, R Maartense, I Peterson, TL Solomon, J Moser, EK Dempsey, D Busbee, J Liptak, D Kozlowski, G Nekkanti, R Oberly, CE AF Varanasi, C Biggers, R Maartense, I Peterson, TL Solomon, J Moser, EK Dempsey, D Busbee, J Liptak, D Kozlowski, G Nekkanti, R Oberly, CE TI YBa2Cu3O7-x-Ag thick films deposited by pulsed laser ablation SO PHYSICA C LA English DT Article DE applications of high T-c superconductors; thin films; ac susceptibility AB Ag-doped YBa2Cu3O7-x films, with thickness ranging from 0.06 to 2.5 mu m, were deposited by pulsed laser ablation onto (100) LaAlO3 single-crystal substrates. The target was YBa2Cu3O7-x with 5 wt.% Ag addition. The presence of Ag in the films in concentrations of similar to 1 at.% was detected by X-ray fluorescence and secondary ion mass spectrometry (SIMS) analysis. Biaxial alignment of the films was indicated by phi scans with full-width-half-maximum (FWHM) spread of 1-2 degrees for various thicknesses. Utilizing a standard deposition process, most films showed a critical transition temperature (T-c) > 90 K as measured by the ac susceptibility technique. Film critical current densities (J(c)) on the order of 10(6) A/cm(2) were measured at 77 K with a four-probe technique on a 100-mu m-wide patterned microbridge. (C) 1998 Elsevier Science B.V. C1 USAF, Res Lab, Wright Patterson AFB, OH 45433 USA. RP Varanasi, C (reprint author), Univ Dayton, Res Inst, 300 Coll Pk, Dayton, OH 45469 USA. EM varanoc@possum.appl.wpafb.af.mil NR 13 TC 7 Z9 8 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD MAR 10 PY 1998 VL 297 IS 3-4 BP 262 EP 268 DI 10.1016/S0921-4534(98)00011-2 PG 7 WC Physics, Applied SC Physics GA ZM548 UT WOS:000073551200013 ER PT J AU Fajardo, ME Tam, S AF Fajardo, ME Tam, S TI Rapid vapor deposition of millimeters thick optically transparent parahydrogen solids for matrix isolation spectroscopy SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID INFRARED-ABSORPTION; HYDROGEN; DEUTERIUM; CRYSTALS; MERCURY; CHARGE; ATOMS; ARGON; LASER; NEON AB We report the rapid vapor deposition of millimeters thick parahydrogen (pH(2)) solids of remarkable optical clarity. Characterization of pure pH(2) samples by IR and Raman spectra show a very low orthohydrogen and vacancy content, and a mixed hexagonal-closed-packed/face-centered-cubic (hcp/fcc) polycrystalline structure for as-deposited samples, which converts to hcp upon annealing. Efficient isolation of atomic and molecular dopants is achieved by conventional matrix isolation spectroscopy (MIS) techniques. The increased optical path lengths offer significant improvements in spectroscopic data quality, and reveal novel dopant-induced IR absorptions of the pH(2) matrix host itself. Thus, while traditional MIS studies in rare gas hosts can only probe the influence of the matrix environment on the spectrum of the dopant "solute," in pH(2) the response of the host "solvent" is directly observable as well. This complementary information may prove to be the key to identifying conclusively the microscopic structures of dopant trapping sites. (C) 1998 American Institute of Physics. [S0021-9606(98)03910-5]. C1 USAF, Res Lab, Prop Directorate, PRSP, Edwards AFB, CA 93524 USA. RP Fajardo, ME (reprint author), USAF, Res Lab, Prop Directorate, PRSP, Bldg 8451, Edwards AFB, CA 93524 USA. NR 31 TC 97 Z9 97 U1 1 U2 11 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD MAR 8 PY 1998 VL 108 IS 10 BP 4237 EP 4241 DI 10.1063/1.475822 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA ZA530 UT WOS:000072373500045 ER PT J AU Binder, JL AF Binder, JL TI Faster, farther, fuller SO HOSPITALS & HEALTH NETWORKS LA English DT Letter C1 USAF, Langley AFB, VA USA. RP Binder, JL (reprint author), USAF, Langley AFB, VA USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER HOSPITAL PUBL INC PI CHICAGO PA 737 N MICHIGAN AVE, CHICAGO, IL 60611-2615 USA SN 1068-8838 J9 HOSP HEALTH NETWORK JI Hosp. Health Netw. PD MAR 5 PY 1998 VL 72 IS 5 BP 8 EP 8 PG 1 WC Health Policy & Services SC Health Care Sciences & Services GA ZC239 UT WOS:000072556500002 ER PT J AU Parthasarathy, TA Keller, M Mendiratta, MG AF Parthasarathy, TA Keller, M Mendiratta, MG TI The effect of lamellar lath spacing on the creep behavior of Ti-47at% Al SO SCRIPTA MATERIALIA LA English DT Article ID ELEVATED-TEMPERATURE; DEFORMATION; ALLOY; STABILITY C1 USAF, Res Lab, WL MLLM, Wright Patterson AFB, OH 45433 USA. RP Parthasarathy, TA (reprint author), Universal Energy Syst Inc, Dayton, OH 45432 USA. RI Parthasarathy, Triplicane/B-7146-2011 OI Parthasarathy, Triplicane/0000-0002-5449-9754 NR 16 TC 52 Z9 54 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6462 J9 SCRIPTA MATER JI Scr. Mater. PD MAR 3 PY 1998 VL 38 IS 7 BP 1025 EP 1031 DI 10.1016/S1359-6462(98)00014-1 PG 7 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA ZC736 UT WOS:000072611400002 ER PT J AU Reed, JB Morse, LS Schwab, IR AF Reed, JB Morse, LS Schwab, IR TI High-dose intravenous pulse methylprednisolone hemisuccinate in acute Behcet retinitis SO AMERICAN JOURNAL OF OPHTHALMOLOGY LA English DT Article ID THERAPY AB PURPOSE: To report the response of acute Behcet retinitis to high-dose corticosteroids. METHOD: Case report. A 58 year-old man with Behcet disease and severe bilateral glaucoma experienced a sudden decrease of visual acuity to counting fingers in his (better-seeing) left eye. Examination disclosed hypopyon uveitis and an infiltrative retinitis threatening the fovea. He received intravenous methylprednisolone hemisuccinate, 1 gram per hour on each of 3 successive days, followed by oral prednisone and cyclosporine. RESULTS: The retinal infiltrate disappeared within 24 hours. Visual acuity improved to LE, 20/400 by day 5 and returned to LE, 20/30 after 3 months. A visual field demonstrated a scotoma corresponding to the location of the previous retinitis. CONCLUSION: High-dose intravenous methyl prednisolone can reverse severe vision loss in acute Behcet retinitis. (C) 1998 by Elsevier Science Inc. All rights reserved. C1 Univ Calif Davis, Dept Ophthalmol, Med Ctr, Sacramento, CA 95816 USA. USAF, Inst Technol, Washington, DC USA. RP Schwab, IR (reprint author), Univ Calif Davis, Dept Ophthalmol, Med Ctr, 1603 Alhambra Blvd, Sacramento, CA 95816 USA. OI Morse, Lawrence/0000-0002-1758-2348 NR 5 TC 11 Z9 12 U1 0 U2 0 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 0002-9394 J9 AM J OPHTHALMOL JI Am. J. Ophthalmol. PD MAR PY 1998 VL 125 IS 3 BP 409 EP 411 PG 3 WC Ophthalmology SC Ophthalmology GA ZA590 UT WOS:000072379800027 PM 9512170 ER PT J AU Beheshti, MV Protzer, WR Tomlinson, TL Martinek, E Baatz, LA Collins, MS AF Beheshti, MV Protzer, WR Tomlinson, TL Martinek, E Baatz, LA Collins, MS TI Long-term results of radiologic placement of a central vein access device SO AMERICAN JOURNAL OF ROENTGENOLOGY LA English DT Article ID SUBCUTANEOUS INFUSION PORTS; VENOUS ACCESS; PAS-PORT; ATRIAL CATHETER; SYSTEM; CHEMOTHERAPY; EXPERIENCE; CANCER AB OBJECTIVE. We describe our long-term experience with radiologic implantation of the Peripheral Access System (PAS) Port venous access device. Technical efficacy and complications are documented and compared with surgical and radiologic series involving other long-term venous access devices. SUBJECTS AND METHODS. Fifty-two PAS-Port catheters were implanted in 51 patients during a 30-month period. All procedures took place in the angiography suite and were performed by interventional radiologists with imaging guidance. Patients were followed up through the oncology clinic or the clinic that originally referred the patient. The durability of the catheter was evaluated, and complications were recorded during the study period. RESULTS. Fifty-two ports have been indwelling for a total of 18,357 patient-days. The mean time of implantation was 372 days, with a range of 30-825 days. Technical success in implanting the device was 100%. Device-related sepsis occurred in one patient (2%), superficial thrombophlebitis in one patient (2%), skin site dehiscence iri one patient (2%), and deep vein thrombosis in one patient (2%). No instances of catheter occlusion occurred, and all catheters retained the ability to aspirate blood throughout their use. The overall complication rate was 8% (0.22/1000 patient days). CONCLUSION. Radiologic placement of this device is safe and effective. It offers many patients a superior alternative to surgically implanted chest wall ports. Complications are fewer, and chances for technical success are greater. In circumstances where cosmesis is deemed highly important, the PAS-Port device may be preferable to tunneled venous access catheters. C1 USAF, Wright Patterson Med Ctr, Dept Radiol, Wright Patterson AFB, OH 45433 USA. USAF, Wright Patterson Med Ctr, Dept Oncol, Div Internal Med, Wright Patterson AFB, OH 45433 USA. RP Beheshti, MV (reprint author), Radiol Consultants PC, 4 Grayan Ct, Little Rock, AR 72211 USA. NR 19 TC 18 Z9 18 U1 0 U2 0 PU AMER ROENTGEN RAY SOC PI RESTON PA 1891 PRESTON WHITE DR, SUBSCRIPTION FULFILLMENT, RESTON, VA 22091 USA SN 0361-803X J9 AM J ROENTGENOL JI Am. J. Roentgenol. PD MAR PY 1998 VL 170 IS 3 BP 731 EP 734 PG 4 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA YY262 UT WOS:000072129500039 PM 9490964 ER PT J AU Keesling, CA O'Hara, SM Chavez, DR King, LR AF Keesling, CA O'Hara, SM Chavez, DR King, LR TI Sonographic appearance of the bladder after endoscopic incision of ureteroceles SO AMERICAN JOURNAL OF ROENTGENOLOGY LA English DT Article ID CHILDREN AB OBJECTIVE. Our intent was to describe the range of postoperative sonographic appearances of the bladder after endoscopic incision of ureteroceles. CONCLUSION. Preoperative and postoperative sonographic examinations of the bladder were reviewed in 14 patients (15 ureteroceles) who underwent endoscopic ureterocele incision. Five different appearances of the ureterovesical junction after endoscopic incision were found: a pseudomass (5/15), focal mucosal thickening (3/15), residual ureterocele with decrease in size (3/15), persistent unchanged ureterocele (1/15), and no residual abnormality (3/15). The most common postoperative sonographic appearance associated with development of vesicoureteral reflux was a mucosal pseudomass (4/6). The other bladder sonographic appearances had no correlation with development of reflux, degree of hydronephrosis, or success of the surgery. C1 Duke Univ, Med Ctr, Dept Radiol, Durham, NC 27710 USA. Duke Univ, Med Ctr, Dept Urol, Durham, NC 27710 USA. RP Keesling, CA (reprint author), Wilford Hall USAF Med Ctr, 59MDW-MTRD,2200 Berquist Dr,Ste 1, Lackland AFB, TX 78236 USA. NR 9 TC 3 Z9 3 U1 0 U2 0 PU AMER ROENTGEN RAY SOC PI RESTON PA 1891 PRESTON WHITE DR, SUBSCRIPTION FULFILLMENT, RESTON, VA 22091 USA SN 0361-803X J9 AM J ROENTGENOL JI Am. J. Roentgenol. PD MAR PY 1998 VL 170 IS 3 BP 759 EP 763 PG 5 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA YY262 UT WOS:000072129500045 PM 9490970 ER PT J AU Ritchie, JR Miller, MD Bents, RT Smith, DK AF Ritchie, JR Miller, MD Bents, RT Smith, DK TI Meniscal repair in the goat model - The use of healing adjuncts on central tears and the role of magnetic resonance arthrography in repair evaluation SO AMERICAN JOURNAL OF SPORTS MEDICINE LA English DT Article; Proceedings Paper CT Annual Meeting of the AAOS CY FEB, 1996 CL ATLANTA, GEORGIA SP AAOS ID TREPHINATION; KNEE; MR AB We evaluated the effect of adjunctive healing measures on central tears of the adult goat medial meniscus and the role of magnetic resonance arthrography in the assessment of menisci that have undergone a repair. Peripheral tears were made unilaterally in the medial menisci of seven goats in Group I and repaired with nonabsorbable suture. Six Group II goats had central medial meniscal tears repaired as in Group I plus an exogenous fibrin clot. Eight Group III goats had central tears plus abrasion of the parameniscal synovium and tear edges. Six months after surgery, a magnetic resonance imaging scan and a magnetic resonance arthrogram were obtained and the menisci were examined grossly. Group I goats showed healing in all seven knees. Central tears repaired with a fibrin clot (Group II) showed healing in one of six knees (17%). Central tears repaired with abrasion (Group Ill)showed healing in seven of eight knees (87.5%). Magnetic resonance arthrography was 100% accurate in detecting the presence or absence of complete residual tears. This study supports the current trend of using adjunctive measures for repair of central tears. Furthermore, abrasion of the parameniscal synovium and the tear edges appears to be more effective than the use of an exogenous fibrin clot. Magnetic resonance arthrography is useful in the evaluation of menisci that have undergone repair. C1 Wilford Hall USAF Med Ctr, Dept Orthopaed Surg, Lackland AFB, TX 78236 USA. Wilford Hall USAF Med Ctr, Dept Radiol, Lackland AFB, TX 78236 USA. RP Ritchie, JR (reprint author), Us Ctr Sports Med, 333 S Kirkwood Rd,Suite 200, St Louis, MO 63122 USA. NR 33 TC 30 Z9 30 U1 0 U2 3 PU AMER ORTHOPAEDIC SOC SPORT MED PI WALTHAM PA 230 CALVARY STREET, WALTHAM, MA 02154 USA SN 0363-5465 J9 AM J SPORT MED JI Am. J. Sports Med. PD MAR-APR PY 1998 VL 26 IS 2 BP 278 EP 284 PG 7 WC Orthopedics; Sport Sciences SC Orthopedics; Sport Sciences GA ZD693 UT WOS:000072713500020 PM 9548124 ER PT J AU Hagan, LL Goetz, DW Revercomb, CH Garriott, J AF Hagan, LL Goetz, DW Revercomb, CH Garriott, J TI Sudden infant death syndrome: a search for allergen hypersensitivity SO ANNALS OF ALLERGY ASTHMA & IMMUNOLOGY LA English DT Article ID COT DEATH; ANAPHYLAXIS; SERUM AB Background: Sudden infant death syndrome (SIDS) remains a diagnosis by exclusion which leaves few if any pathologic clues to its etiology. Previous evaluations for anaphylaxis in SIDS have been few and limited. Objective: To analyze forensic blood specimens for evidence of anaphylaxis in 51 (43 boys and 8 girls) children dying of SIDS and 13 (9 boys and 4 girls) age-matched controls who died from defined, nonanaphylactic causes. Methods: Specimens collected over a 5-year period were assayed for (1) total IgE (IU/mL) by immunoenzymatic assay; (2) latex, cat, dust mite (Dermatophagoides farinae and Dermatophagoides pteronyssinus), milk, soy, wheat, peanuts, egg, and tomato specific-IgE by PAST; and (3) serum tryptase levels (U/L) by radioimmunoassay. Results: The 51 SIDS cases (median age 3 months; range 1 to 9 months) and 13 control cases (median age 4 months; range 1 to 11 months) demonstrated similar total IgE of 9.8 +/- 1.1 IU/mL (mean +/- SEM) and 10.9 +/- 2.8 IU/mL (P =.59). The frequency of detectable (>0.5 U/L) serum tryptase levels among SIDS cases (10/51) was similar to controls (3/13, P =.72). The frequency of positive PAST tests was 39% (20/51) in SIDS and 38% (5/13) in control subjects (P =.99). Differences in frequencies of positive PAST tests in SIDS and control cases were not statistically significant for any allergen tested. The most frequently detected allergen-specific IgE, to milk, was similar in SIDS (22%) and controls (31%, P =.48). Conclusions: Elevated tryptase levels and allergen-specific IgE (milk, soy, wheat, peanuts, egg, tomato, dust mites, cat, and latex) were demonstrated in some infant SIDS deaths but were no more common than in controls. We conclude that anaphylaxis is probably an uncommon etiology for SIDS. C1 Wilford Hall USAF Med Ctr, Allergy Immunol Dept, Lackland AFB, TX 78236 USA. Bexar Cty Forens Sci Ctr, San Antonio, TX USA. RP Goetz, DW (reprint author), 59MDW-MMIA,2200 Berquist Dr,Suite 1, Lackland AFB, TX 78236 USA. NR 14 TC 11 Z9 11 U1 0 U2 0 PU AMER COLL ALLERGY ASTHMA IMMUNOLOGY PI ARLINGTON HTS PA 85 WEST ALGONQUIN RD SUITE 550, ARLINGTON HTS, IL 60005 USA SN 1081-1206 J9 ANN ALLERG ASTHMA IM JI Ann. Allergy Asthma Immunol. PD MAR PY 1998 VL 80 IS 3 BP 227 EP 231 PG 5 WC Allergy; Immunology SC Allergy; Immunology GA ZE352 UT WOS:000072784000003 PM 9532970 ER PT J AU He, ZQ Spain, JC AF He, ZQ Spain, JC TI Studies of the catabolic pathway of degradation of nitrobenzene by Pseudomonas pseudoalcaligenes JS45: Removal of the amino group from 2-aminomuconic semialdehyde (vol 63, pg 4841, 1997) SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Correction C1 USAF, Res Lab, Tyndall AFB, FL 32403 USA. RP He, ZQ (reprint author), USAF, Res Lab, Tyndall AFB, FL 32403 USA. NR 1 TC 0 Z9 0 U1 0 U2 2 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 USA SN 0099-2240 J9 APPL ENVIRON MICROB JI Appl. Environ. Microbiol. PD MAR PY 1998 VL 64 IS 3 BP 1167 EP 1167 PG 1 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA YZ798 UT WOS:000072292700060 ER PT J AU Gundel, DB Miracle, DB AF Gundel, DB Miracle, DB TI The influence of interface structure and composition on the response of single-fiber SiC/Ti-6Al-4V composites to transverse tension SO APPLIED COMPOSITE MATERIALS LA English DT Article DE cruciform specimen geometry; interface strength; interface structure; transverse tensile testing; fiber coatings; titanium matrix composites; SiC fibers; damage; failure ID MATRIX COMPOSITES; SIC FIBER; SCS-6/TI-6AL-4V COMPOSITE; SHEAR-STRENGTH AB The cruciform specimen geometry has recently been established to investigate the transverse tensile behavior of single-fiber or multiple-fiber titanium matrix composites; however, the results on only relatively few commercially-available fibers have been reported to date. The present study reports the transverse behavior of a range of SiC fibers prepared by different manufacturers and with different surface coatings. The mechanical response of the composite and the damage present at the interfacial region have been documented. In general, the stress-strain behavior was found to be sensitive to the chemical and structural nature of the fiber-matrix interfacial region. Fibers with carbon-rich coatings were found to have a range of interfacial strengths depending on the structure of the interface layers, while uncoated fiber interfaces have a high strength. This study demonstrates the value of the single-fiber transverse cruciform test for quantitatively comparing the behavior of various fibers and coatings, and shows that it can be useful for coating development studies. C1 USAF, Wright Lab, Mat Directorate, Wright Patterson AFB, OH 45433 USA. NR 23 TC 11 Z9 11 U1 1 U2 5 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0929-189X J9 APPL COMPOS MATER JI Appl. Compos. Mater. PD MAR PY 1998 VL 5 IS 2 BP 95 EP 108 DI 10.1023/A:1008842913584 PG 14 WC Materials Science, Composites SC Materials Science GA ZD902 UT WOS:000072735900002 ER PT J AU Lombard, D Haddock, CK Talcott, GW Reynes, R AF Lombard, D Haddock, CK Talcott, GW Reynes, R TI Cost-effectiveness analysis: A primer for psychologists SO APPLIED & PREVENTIVE PSYCHOLOGY LA English DT Article DE cost-effectiveness; cost-benefit; cost containment; managed care ID CARE AB Given the move to managed care and capitated budgets, psychologists must now prove that the treatments being offered are clinically effective in allaying symptoms and are cost-effective. Cost-effectiveness analysis (CEA) is often seen as a daunting task requiring one to pour over spread sheets with little empathy for the patient. This article attempts to break this daunting task down into nine reasonable steps. By using CEA, psychologists will have the data to compete for dollars in this time of limited funds. An overriding attempt was made not to use excessive technical jargon or formulas in this review. The goal of this article is to offer the average practitioner, clinic director, or department chair an easily understood method that can be adapted and applied to his or her unique environment. If psychologists, individually and as a profession, choose to ignore the power of CEA, other professionals may step in and take this power and control our future. C1 Wilford Hall USAF Med Ctr, PSCPB, Lackland AFB, TX 78236 USA. RP Lombard, D (reprint author), Wilford Hall USAF Med Ctr, PSCPB, 2200 Bergquist Dr,Suite 1, Lackland AFB, TX 78236 USA. NR 17 TC 5 Z9 5 U1 0 U2 1 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 USA SN 0962-1849 J9 APPL PREV PSYCHOL JI Appl. Prev. Psychol. PD SPR PY 1998 VL 7 IS 2 BP 101 EP 108 DI 10.1016/S0962-1849(05)80007-1 PG 8 WC Psychology, Clinical; Psychology, Applied SC Psychology GA ZG900 UT WOS:000073051300003 ER PT J AU Berman, LM Wolf, PJ AF Berman, LM Wolf, PJ TI Laser-induced breakdown spectroscopy of liquids: Aqueous solutions of nickel and chlorinated hydrocarbons SO APPLIED SPECTROSCOPY LA English DT Article DE emission spectroscopy; laser-induced breakdown spectroscopy; solution samples; chlorinated hydrocarbons; nickel ID LIBS; SPECTROMETRY; ABLATION; SAMPLES; VACUUM; IRON; ORE; AIR AB Spectrochemical analyses of aqueous solutions containing nickel or the chlorinated hydrocarbons (CHCs) C2Cl4, CCl4, CHCl3, and C2HCl3, were performed with the use of laser-induced breakdown spectroscopy. A Nd:YAG laser operating at 60 mJ/pulse was focused onto the surface of the liquid. Elemental line intensities were monitored in the laser-produced plume as a function of analyte concentration to determine detection limits. The limits of detection for nickel in water were 36.4 +/- 5.4 mg/L and 18.0 +/- 3.8 mg/L for laser irradiation at 1.06 mu m and 355 nm, respectively. Ablation of pure CHCs at 355 nm produced extremely intense plasma emissions that primarily consisted of spectroscopic features attributed to CN, C-3, H, N, and Cl. The spectra were structurally identical for all the CHCs except for differences in the intensities of various emission lines. With the use of emission from neutral atomic chlorine as an identifier for CHC contamination of water, no detectable traces of these elements were observed in saturated aqueous solutions. The detection limits for the CHCs were well above the saturation limits of CHC in water. C1 USAF, Inst Technol, Dept Engn Phys, Wright Patterson AFB, OH 45433 USA. RP Wolf, PJ (reprint author), USAF, Inst Technol, Dept Engn Phys, Wright Patterson AFB, OH 45433 USA. NR 29 TC 56 Z9 57 U1 0 U2 9 PU SOC APPLIED SPECTROSCOPY PI FREDERICK PA 201B BROADWAY ST, FREDERICK, MD 21701 USA SN 0003-7028 J9 APPL SPECTROSC JI Appl. Spectrosc. PD MAR PY 1998 VL 52 IS 3 BP 438 EP 443 DI 10.1366/0003702981943644 PG 6 WC Instruments & Instrumentation; Spectroscopy SC Instruments & Instrumentation; Spectroscopy GA ZH219 UT WOS:000073084900020 ER PT J AU Brannon, B AF Brannon, B TI A far from routine mission SO AVIATION SPACE AND ENVIRONMENTAL MEDICINE LA English DT Editorial Material C1 USAF, NC, Med Grp CC 71, Vance AFB, OK 73705 USA. RP Brannon, B (reprint author), USAF, NC, Med Grp CC 71, 527 Gott Rd, Vance AFB, OK 73705 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AEROSPACE MEDICAL ASSOC PI ALEXANDRIA PA 320 S HENRY ST, ALEXANDRIA, VA 22314-3579 USA SN 0095-6562 J9 AVIAT SPACE ENVIR MD JI Aviat. Space Environ. Med. PD MAR PY 1998 VL 69 IS 3 BP 319 EP 320 PG 2 WC Public, Environmental & Occupational Health; Medicine, General & Internal; Sport Sciences SC Public, Environmental & Occupational Health; General & Internal Medicine; Sport Sciences GA ZB215 UT WOS:000072448300011 PM 9549572 ER PT J AU Bostwick, JM AF Bostwick, JM TI The therapeutic alliance. SO BULLETIN OF THE MENNINGER CLINIC LA English DT Book Review C1 Wilford Hall USAF Med Ctr, Dept Psychiat, Lackland AFB, TX 78236 USA. RP Bostwick, JM (reprint author), Wilford Hall USAF Med Ctr, Dept Psychiat, Lackland AFB, TX 78236 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU MENNINGER FOUNDATION PI TOPEKA PA BOX 829, TOPEKA, KS 66601 USA SN 0025-9284 J9 B MENNINGER CLIN JI Bull. Menninger Clin. PD SPR PY 1998 VL 62 IS 2 BP 262 EP 263 PG 2 WC Psychiatry; Psychology, Psychoanalysis SC Psychiatry; Psychology GA ZL349 UT WOS:000073424000010 ER PT J AU Blute, ML Bostwick, DG Seay, TM Martin, SK Slezak, JM Bergstralh, EJ Zincke, H AF Blute, ML Bostwick, DG Seay, TM Martin, SK Slezak, JM Bergstralh, EJ Zincke, H TI Pathologic classification of prostate carcinoma - The impact of margin status SO CANCER LA English DT Article DE prostate carcinoma; pathologic staging; margin status; organ-confined ID RADICAL RETROPUBIC PROSTATECTOMY; POSITIVE SURGICAL MARGINS; MULTIVARIATE-ANALYSIS; CANCER; ANTIGEN; PROGRESSION; SPECIMEN; FAILURE AB BACKGROUND, A proposed pathologic (pTNM) classification system for prostate carcinoma was analyzed for its impact on survival outcome in the prostate specific antigen BSA) era. The impact of margin status on the survival outcome of patients with otherwise organ-confined disease (i.e., without extraprostatic extension or seminal vesicle involvement] was assessed. METHODS. Among 5467 patients, the original pathologic classification was T2 in 2094 patients; those with evidence of positive margins, extraprostatic extension, or seminal vesicle involvement were initially classified as having pT3 disease (2920 patients) or pT4 residual disease (211 patients). According to the proposed pTNM system, 1512 patients for whom margin status was considered independent of T classification were reclassified. RESULTS, After reclassification, 803 specimens had been down-classified to pT2, resulting in 2932 (54%) with pT2N0 organ-confined disease and a margin positivity rate of 27%; originally, only 38% of patients had been classified as pT2N0. When the old and new classifications were compared, 5-year progression free survival to the combined endpoint of clinical and/or PSA progression (less than or equal to 0.2 ng/mL) was 86% versus 84% and 70% versus 67% for disease classified as pT2NO and pT3N0, respectively. Multivariate analysis assessed the effect of margin status on 2334 pT2NO patients (classified according to the proposed pTNM system) who did not receive adjuvant therapy; adjustments were made for Gleason grade, preoperative PSA, and DNA ploidy. In this analysis, the relative risk (with 95% confidence interval) associated with positive margins was 1.65 (1.24-2.18); this was significant for the combined endpoint of clinical/PSA progression. The 5-year survival, free of clinical/PSA progression, was 86% for those without versus 75% for those with positive margins. CONCLUSIONS. This analysis supports the adoption of the proposed pTNM system, which will allow for uniform reporting of pathologic data on prostate carcinoma. For patients with organ-confined disease, positive margins are associated with higher rates of PSA progression. Accordingly, patients should be stratified based on margin positivity in addition to pT classification. (C) 1998 American Cancer Society. C1 Mayo Clin & Mayo Fdn, Dept Urol, Rochester, MN 55905 USA. Mayo Clin, Dept Lab Med & Pathol, Rochester, MN USA. Wilford Hall USAF Med Ctr, Dept Urol, Lackland AFB, TX 78236 USA. Mayo Clin, Dept Biostat, Rochester, MN USA. RP Blute, ML (reprint author), Mayo Clin & Mayo Fdn, Dept Urol, 200 1St St Sw, Rochester, MN 55905 USA. NR 20 TC 73 Z9 74 U1 0 U2 0 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC, 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0008-543X J9 CANCER JI Cancer PD MAR 1 PY 1998 VL 82 IS 5 BP 902 EP 908 DI 10.1002/(SICI)1097-0142(19980301)82:5<902::AID-CNCR15>3.0.CO;2-4 PG 7 WC Oncology SC Oncology GA YY439 UT WOS:000072146700015 PM 9486580 ER PT J AU Oldfield, EC Fessel, WJ Dunne, MW Dickinson, G Wallace, MR Byrne, W Chung, R Wagner, KF Paparello, SF Craig, DB Melcher, G Zajdowicz, M Williams, RF Kelly, JW Zelasky, M Heifets, LB Berman, JD AF Oldfield, EC Fessel, WJ Dunne, MW Dickinson, G Wallace, MR Byrne, W Chung, R Wagner, KF Paparello, SF Craig, DB Melcher, G Zajdowicz, M Williams, RF Kelly, JW Zelasky, M Heifets, LB Berman, JD TI Once weekly azithromycin therapy for prevention of Mycobacterium avium complex infection in patients with AIDS: A randomized, double-blind, placebo-controlled multicenter trial SO CLINICAL INFECTIOUS DISEASES LA English DT Article ID HUMAN-IMMUNODEFICIENCY-VIRUS; CLARITHROMYCIN; PROPHYLAXIS; BACTEREMIA; SURVIVAL; RIFABUTIN; RESISTANT; DISEASE; IMPACT AB We conducted a randomized, double-blind, placebo-controlled multicenter trial of azithromycin (1,200 mg once weekly) for the prevention of Mycobacterium avium complex (MAC) infection in patients with AIDS and a CD4 cell count of <100/mm(3), In an intent-to-treat analysis through the end of therapy plus 30 days, nine (10.6%) of 85 azithromycin recipients and 22 (24.7%) of 89 placebo recipients developed MAC infection (hazard ratio, 0.34; P = .004), There was no difference in the ranges of minimal inhibitory concentrations of either clarithromycin or azithromycin for the five breakthrough (first) MAC isolates from the azithromycin group and the 18 breakthrough MAC isolates from the placebo group, Of the 76 patients who died during the study, four (10.5%) of 38 azithromycin recipients and 12 (31.6%) of 38 placebo recipients had a MAC infection followed by death (P = .025), For deaths due to all causes, there was no difference in time to death or number of deaths between the two groups, Episodes of non-MAC bacterial infection per 100 patient years occurred in 43 azithromycin recipients and 88 placebo recipients (relative risk, 0.49; 95% confidence interval, 0.33-0.73), The most common toxic effect noted during the study was gastrointestinal, reported by 78.9% of azithromycin recipients and 27.5% of placebo recipients, Azithromycin given once weekly is safe and effective in preventing disseminated MAC infection, death due to MAC infection, and respiratory tract infections in patients with AIDS and CD4 cell counts of <100/mm(3). C1 USN Hosp, San Diego, CA 92134 USA. Kaiser Permanente, San Francisco, CA USA. Vet Affairs Med Ctr, Miami, FL 33125 USA. Walter Reed Army Med Ctr, Washington, DC 20307 USA. Mil Med Consortium Appl Retroviral Res, Washington, DC USA. Fitzsimons Army Med Ctr, Aurora, CO 80045 USA. Natl Jewish Ctr Immunol & Resp Med, Denver, CO 80206 USA. Natl Naval Med Ctr, Bethesda, MD USA. Wilford Hall USAF Med Ctr, Lackland AFB, TX 78236 USA. Brooke Army Med Ctr, Ft Sam Houston, TX 78234 USA. USA, Dwight D Eisenhower Med Ctr, Ft Gordon, GA USA. Womack Army Med Ctr, Portsmouth, VA USA. Pfizer Inc, Pfizer Cent Res, Groton, CT 06340 USA. RP Oldfield, EC (reprint author), Eastern Virginia Med Sch, Dept Internal Med, Div Infect Dis, 825 Fairfax Ave, Norfolk, VA 23507 USA. NR 26 TC 47 Z9 49 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5801 S ELLIS AVENUE, CHICAGO, IL 60637 USA SN 1058-4838 J9 CLIN INFECT DIS JI Clin. Infect. Dis. PD MAR PY 1998 VL 26 IS 3 BP 611 EP 619 DI 10.1086/514566 PG 9 WC Immunology; Infectious Diseases; Microbiology SC Immunology; Infectious Diseases; Microbiology GA YZ745 UT WOS:000072287400012 PM 9524832 ER PT J AU Naboulsi, S Mall, S AF Naboulsi, S Mall, S TI Nonlinear analysis of bonded composite patch repair of cracked aluminum panels SO COMPOSITE STRUCTURES LA English DT Article AB Analyses of adhesively bonded composite patches to repair cracked structures have been the focus of many studies. Most of these studies investigated the damage tolerance of the repaired structure by using linear analysis. This study involves nonlinear analysis of the adhesively bonded composite patch to investigate its effects on the damage tolerance of the repaired structure. The nonlinear analysis utilizes the three-layer technique which includes geometric nonlinearity to account for large displacements of the repaired structure and also material nonlinearity of the adhesive. The three-layer technique uses two-dimensional finite element analysis with Mindlin plate elements to model the cracked plate, adhesive and composite patch. The effects of geometric nonlinearity on the damage tolerance of the cracked plate is investigated by computing the stress intensity factor and fatigue growth rate of the crack in the plate. The adhesive is modeled as a nonlinear material to characterize debond behavior. The elastic-plastic analysis of the adhesive utilizes the extended Drucker-Prager model. A detailed discussion on the effects of nonlinear analysis for a bonded composite patch repair of a cracked aluminum panel is presented in this paper. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 USAF, Inst Technol, Dept Aeronaut & Astronaut, Wright Patterson AFB, OH 45433 USA. RP Mall, S (reprint author), USAF, Inst Technol, Dept Aeronaut & Astronaut, Wright Patterson AFB, OH 45433 USA. NR 21 TC 42 Z9 46 U1 3 U2 4 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0263-8223 J9 COMPOS STRUCT JI Compos. Struct. PD MAR-APR PY 1998 VL 41 IS 3-4 BP 303 EP 313 DI 10.1016/S0263-8223(98)00052-X PG 11 WC Materials Science, Composites SC Materials Science GA 121BC UT WOS:000075991400010 ER PT J AU Pai, PF Palazotto, AN Greer, JM AF Pai, PF Palazotto, AN Greer, JM TI Polar decomposition and appropriate strains and stresses for nonlinear structural analyses SO COMPUTERS & STRUCTURES LA English DT Article ID PLASTIC WORK; DEFORMATION; FORMULATION; SOLIDS; SHELLS; PATHS AB Work conjugacy, objectivity, vector expressions, directions and limitations of major pairs of stress and strain measures used in geometrically nonlinear and elastoplastic analyses of structures are investigated. Polar decomposition is examined in detail. For geometrically nonlinear analysis, Jaumann strains and stresses are the most appropriate pair of measures because Jaumann strains are proved to be objective (invariant under rigid-body rotations) corotated engineering strains. It is shown that Jaumann strains can be easily derived by using a new concept of local displacements without using the complex polar decomposition procedure. Moreover, the use of Jaumann stresses and strains results in a direct correlation between energy and Newtonian approaches and makes all structural energy terms interpretable in terms of vectors. For elastoplastic analysis, corotated Cauchy stresses and corotated Eulerian strain rates are shown to be the most appropriate pair of measures. Moreover, if the deformation follows the minimum work path, it is proved that corotated Eulerian strain rates correspond to the simultaneous variation of true stretches at a fixed ratio along the three fixed principal material lines. The derived corotated Cauchy stresses and Eulerian strain rates are useful in analyzing elastoplastic, viscoelastic and viscoplastic materials in deformation processing, such as metalforming. (C) 1998 Elsevier Science Ltd. All tights reserved. C1 Univ Missouri, Dept Mech & Aerosp Engn, Columbia, MO 65211 USA. USAF, Inst Technol, Dept Aeronaut & Astronaut, Wright Patterson AFB, OH 45433 USA. USAF, Wright Lab, Flight Dynam Directorate, Wright Patterson AFB, OH 45433 USA. RP Pai, PF (reprint author), Univ Missouri, Dept Mech & Aerosp Engn, Columbia, MO 65211 USA. NR 27 TC 13 Z9 15 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0045-7949 J9 COMPUT STRUCT JI Comput. Struct. PD MAR PY 1998 VL 66 IS 6 BP 823 EP 840 DI 10.1016/S0045-7949(98)00004-2 PG 18 WC Computer Science, Interdisciplinary Applications; Engineering, Civil SC Computer Science; Engineering GA ZT129 UT WOS:000074051400009 ER PT J AU Reigelsperger, WC Banda, SS AF Reigelsperger, WC Banda, SS TI Nonlinear simulation of a modified F-16 with full-envelope control laws SO CONTROL ENGINEERING PRACTICE LA English DT Article DE robust flight control; full-envelope control; mu-synthesis; dynamic inversion; control-allocation ID FLIGHT CONTROL DESIGN; OF-ATTACK FLIGHT AB A manual flight-control system for a modern fighter aircraft incorporating thrust vectoring is presented. Design goals are posed in terms of maintaining acceptable flying qualities during high-angle-of-attack (AOA) maneuvering, while also achieving robustness to model parameter variations and unmodeled dynamics over the entire flight envelope. The need for gain scheduling is eliminated by using an inner-loop dynamic inversion/outer-loop structured singular value (mu) - synthesis control structure which separately addresses operating envelope variations and robustness concerns, respectively. Realistic representations of both structured (real parametric) and unstructured uncertainty are included in the design/analysis process. A flight-condition-dependent control selector maps generalized controls to physical control deflections. Simulation maneuvers showed excellent control at both low and high angles of attack, without scheduling dynamic controllers. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 USAF, Wright Lab, Flight Dynam Directorate, Wright Patterson AFB, OH 45433 USA. RP Reigelsperger, WC (reprint author), USAF, Wright Lab, Flight Dynam Directorate, WL-FIGC Bldg 146,2210 8th St,STE 21, Wright Patterson AFB, OH 45433 USA. NR 21 TC 13 Z9 15 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0967-0661 J9 CONTROL ENG PRACT JI Control Eng. Practice PD MAR PY 1998 VL 6 IS 3 BP 309 EP 320 DI 10.1016/S0967-0661(98)00024-0 PG 12 WC Automation & Control Systems; Engineering, Electrical & Electronic SC Automation & Control Systems; Engineering GA ZZ157 UT WOS:000074701400001 ER PT J AU Michalek, JE Tripathi, RC Kulkarni, PM Gupta, PL Selvavel, K AF Michalek, JE Tripathi, RC Kulkarni, PM Gupta, PL Selvavel, K TI Correction for bias introduced by truncation in pharmacokinetic studies of environmental contaminants SO ENVIRONMETRICS LA English DT Article DE biomarker; decay rate; least squares; regression toward the mean ID OPERATION RANCH HAND; HALF-LIFE; VETERANS; REGRESSION; VIETNAM AB Pharmacokinetic studies of biomarkers for environmental contaminants in humans are generally restricted to a few measurements per subject taken after the initial exposure. Subjects are selected for inclusion in the study if their measured body burden is above a threshold determined by the distribution of the biomarker in a control population. Such selection procedures introduce bias in the ordinary weighted least squares estimate of the decay rate lambda caused by the truncation. We show that if the data are conditioned to lie above a line with slope - lambda on the log scale then the weighted least squares estimate of lambda is unbiased. We give an iterative estimation algorithm that produces this unbiased estimate with commercially available software for fitting a repeated measures linear model. The estimate and its efficiency are discussed in the context of a pharmacokinetic study of 2,3,7,8-tetrachlorodibenzo-p-dioxin. Unbiasedness and efficiency are demonstrated with a simulation. (C) 1998 John Wiley & Sons, Ltd. C1 USAF, Directed Energy Bioeffects Div, Res Lab, Brooks AFB, TX 78235 USA. Univ Texas, Dept Math & Stat, San Antonio, TX 78249 USA. Univ S Alabama, Dept Math & Stat, Mobile, AL 36688 USA. Univ Maine, Dept Math, Orono, ME 04469 USA. Claflin Coll, Dept Math & Comp Sci, Orangeburg, SC 29115 USA. RP Michalek, JE (reprint author), USAF, Directed Energy Bioeffects Div, Res Lab, Brooks AFB, TX 78235 USA. NR 17 TC 7 Z9 7 U1 0 U2 2 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 1180-4009 J9 ENVIRONMETRICS JI Environmetrics PD MAR-APR PY 1998 VL 9 IS 2 BP 165 EP 174 DI 10.1002/(SICI)1099-095X(199803/04)9:2<165::AID-ENV293>3.0.CO;2-6 PG 10 WC Environmental Sciences; Mathematics, Interdisciplinary Applications; Statistics & Probability SC Environmental Sciences & Ecology; Mathematics GA ZG988 UT WOS:000073060600005 ER PT J AU Michalek, JE Rahe, AJ Boyle, CA AF Michalek, JE Rahe, AJ Boyle, CA TI Paternal dioxin, preterm birth, intrauterine growth retardation, and infant death SO EPIDEMIOLOGY LA English DT Article DE dioxin; infant death; intrauterine growth retardation; preterm birth; prenatal exposures ID OPERATION RANCH HAND; SERUM DIOXIN; REPRODUCTIVE OUTCOMES; VETERANS; 2,3,7,8-TETRACHLORODIBENZO-PARA-DIOXIN; EXPOSURE; GONADOTROPINS; TESTOSTERONE; TOXICITY AB We studied paternal exposure to Agent Orange and its dioxin contaminant (2,3,7,8 tetrachlorodibenzo-p-dioxin) and preterm birth, intrauterine growth retardation, or infant death in veterans of Operation Ranch Hand, the unit responsible for spraying herbicides during the Vietnam war. A Comparison group of Air Force veterans who served in Southeast Asia during the same time period and who were not occupationally exposed to herbicides was included. We studied children conceived during or after the father's service in Southeast Asia and based exposure on paternal dioxin measured in 1987 or 1992 extrapolated to the time of conception of the child. We assigned each child to one of four exposure categories: Comparison and three Ranch Hand categories (Background, Low, High). Children in the High (relative risk = 1.3) and Background (relative risk = 1.4) categories were at increased risk of preterm birth. The risk of intrauterine growth retardation was not increased in any exposure category. The risk of infant death was increased in all Ranch Hand children, with the greatest increases in the High (relative risk = 4.5) and Background (relative risk = 3.2) categories. These patterns indicate that the increases in the relative risk of preterm birth and infant death may not be related to paternal dioxin level. C1 Armstrong Lab, Brooks AFB, TX 78235 USA. Vista Technol Inc, San Antonio, TX USA. Ctr Dis Control & Prevent, Atlanta, GA USA. RP Michalek, JE (reprint author), AFRL-HEDB,2606 Doolittle Rd,Bldg 807, Brooks AFB, TX 78232 USA. NR 27 TC 26 Z9 26 U1 0 U2 8 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 USA SN 1044-3983 J9 EPIDEMIOLOGY JI Epidemiology PD MAR PY 1998 VL 9 IS 2 BP 161 EP 167 DI 10.1097/00001648-199803000-00010 PG 7 WC Public, Environmental & Occupational Health SC Public, Environmental & Occupational Health GA YX941 UT WOS:000072096000010 PM 9504284 ER PT J AU Hastie, RL Fredell, R Dally, JW AF Hastie, RL Fredell, R Dally, JW TI A photoelastic study of crack repair SO EXPERIMENTAL MECHANICS LA English DT Article AB Birefringent coatings have been employed to study the effectiveness of an adhesively bonded repair of a center-cracked tension panel. The repair was one sided, with photoelastic coatings applied to the opposite side. Photoelastic coatings were also applied over the patch. Analysis methods are presented to permit the stress intensity factor to be determined from the isochromatic fringe patterns recorded from both continuous and X-and Y-edged coatings. The results showed that the one-sided adhesively bonded patch reduced the stress intensity factor; however, the repair did not markedly change the character of stress distributions. Fringe loops formed near the crack tips for both the cracked and repaired tension panels. The primary difference was in the size of the loops. The reduction in K-I due to repair was smaller than anticipated, but even small improvements in Delta K-I markedly enhance the life of a repaired panel. The Paris power law is used to show the relation between the reduction in Delta K-I and the improvement in the crack growth rate da/dN. Fringe patterns from the birefringent coatings applied to the patch provided a means not only to investigate the stresses in the patch but also to detect the initiation of the local debonding of the adhesive in the neighborhood of the crack. The birefringent coating on the patch is an approach for producing an optically "smart" repair. C1 USAF Acad, Dept Mech Engn, Colorado Springs, CO 80840 USA. Univ Maryland, Dept Mech Engn, College Pk, MD 20742 USA. RP Hastie, RL (reprint author), USAF Acad, Dept Mech Engn, Colorado Springs, CO 80840 USA. NR 10 TC 3 Z9 5 U1 0 U2 2 PU SAGE PUBLICATIONS INC PI THOUSAND OAKS PA 2455 TELLER RD, THOUSAND OAKS, CA 91320 USA SN 0014-4851 J9 EXP MECH JI Exp. Mech. PD MAR PY 1998 VL 38 IS 1 BP 29 EP 36 DI 10.1007/BF02321264 PG 8 WC Materials Science, Multidisciplinary; Mechanics; Materials Science, Characterization & Testing SC Materials Science; Mechanics GA YZ513 UT WOS:000072261600006 ER PT J AU Gogineni, S Goss, L Roquemore, M AF Gogineni, S Goss, L Roquemore, M TI Manipulation of a jet in a cross flow SO EXPERIMENTAL THERMAL AND FLUID SCIENCE LA English DT Article DE particle image velocimetry; particle imaging; mixing; jet in cross flow; Jet control ID AIR-JET AB The effect of forcing on the mixing and velocity field of a jet in a cross flow is investigated for a jet-to-cross flow velocity ratio of R = 1.0 using reactive-Mie-scattering flow-visualization and two-color Particle Image Velocimetry (PIV) techniques. Reactive-Mie-scattering images are used to assess the effect of forcing on molecular mixing, whereas double-exposed two-color PIV images are employed to obtain instantaneous velocity and corresponding vorticity distributions. The jet emanates from a square conduit and is manipulated by four piezoelectric actuators - one mounted along each side of the jet conduit near the jet-exit plane. Time-and phase-averaged distributions of velocity and rms velocity fluctuations in the x-y plane z = 0 are also obtained. A novel approach is employed for processing jet and cross-flow fluids based on the size of the seeding particle. The present results show that when the jet is unforced, the "wake" of the jet contains a domain in which the magnitude of the velocity is very low compared to that of the cross-flow velocity, suggesting that the fluid within this domain is almost stagnant. When the jet is excited, the low-velocity domain in its wake is substantially reduced through vigorous mixing. Manipulation of the upstream and downstream segments of the jet sheer layer also leads to an increase in the jet penetration into the cross flow (up to 30% as compared to the unforced case) and substantial mixing enhancement. Unlike in streamwise forcing where the jet fluid remains mainly in the central portion of the spanwise surface, spanwise forcing induces strong spanwise jet undulations. (C) 1998 Elsevier Science Inc. All rights reserved. C1 Innovat Sci Solut Inc, Dayton, OH 45440 USA. Air Force Res Lab, Propuls Directorate, Wright Patterson AFB, OH 45433 USA. RP Gogineni, S (reprint author), Innovat Sci Solut Inc, 2786 Indian Ripple Rd, Dayton, OH 45440 USA. NR 18 TC 14 Z9 14 U1 1 U2 6 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 0894-1777 J9 EXP THERM FLUID SCI JI Exp. Therm. Fluid Sci. PD MAR PY 1998 VL 16 IS 3 BP 209 EP 219 DI 10.1016/S0894-1777(97)10028-0 PG 11 WC Thermodynamics; Engineering, Mechanical; Physics, Fluids & Plasmas SC Thermodynamics; Engineering; Physics GA ZU367 UT WOS:000074190000005 ER PT J AU Kovanis, V Grigolini, P Kenkre, VM Tsironis, GP AF Kovanis, V Grigolini, P Kenkre, VM Tsironis, GP TI Fractal dimensions in tunneling processes and effects of environmental fluctuations SO FRACTALS-AN INTERDISCIPLINARY JOURNAL ON THE COMPLEX GEOMETRY OF NATURE LA English DT Article ID ELECTRON WAVE-PACKETS; TRAVERSAL TIME; QUANTUM-THEORY; CHAOS AB We study electron tunneling between two infinite potential square wells connected via an opaque barrier and find that time evolution of the probability of the presence of a Gaussian wave packet, localized initially in one of the wells, shares the fractal behavior of tunneling in a quartic potential, discovered by Dekker (H. Dekker, Phys. Rev. A35, 1825 (1987). However, the fractal dimensions are found to be closer to those of a conventional Weierstrass function than those appropriate to the quasi-Weierstrass behavior of Dekker. It is argued that the usual exponential decay predicted by conventional relaxation processes can be recovered only as an effect of thermal fluctuations. C1 USAF, Phillips Lab, Kirtland AFB, NM 87117 USA. Univ N Texas, Dept Phys, Denton, TX 76203 USA. Univ New Mexico, Ctr Adv Studies, Albuquerque, NM 87131 USA. Univ New Mexico, Dept Phys & Astron, Albuquerque, NM 87131 USA. Univ Crete, Dept Phys, GR-71003 Heraklion, Crete, Greece. Fdn Res & Technol Hellas, GR-71003 Heraklion, Crete, Greece. RP Kovanis, V (reprint author), USAF, Phillips Lab, Kirtland AFB, NM 87117 USA. RI Tsironis, George/C-2683-2011 NR 32 TC 0 Z9 0 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 9128, SINGAPORE SN 0218-348X J9 FRACTALS JI Fractals-Interdiscip. J. Complex Geom. Nat. PD MAR PY 1998 VL 6 IS 1 BP 59 EP 66 DI 10.1142/S0218348X98000079 PG 8 WC Mathematics, Interdisciplinary Applications; Multidisciplinary Sciences SC Mathematics; Science & Technology - Other Topics GA ZL390 UT WOS:000073428100006 ER PT J AU Lee, MC Riddolls, RJ Burke, WJ Sulzer, MP Klien, EMC Rowlands, MJ Kuo, SP AF Lee, MC Riddolls, RJ Burke, WJ Sulzer, MP Klien, EMC Rowlands, MJ Kuo, SP TI Ionospheric plasma bubble generated by Arecibo heater SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID RADIO-WAVES; SPREAD-F; CAVITIES; MOTION AB During recent experiments ionospheric plasma bubbles were excited by the upgraded HF heater at Arecibo. These plasma bubbles were observed by radar in the midnight sector with the entire flux tube in darkness. A simple model is outlined to explain the dynamics of density depletions generated during O-mode wave heating of the F layer. We suggest that thermal expansion of plasma away from the heated volume leads to enhanced recombination along the flux tube. In the absence of photoionization sources, density depletions develop along the excited flux tube. The discontinuity of gravity-driven currents at the walls of the depleted region requires development of polarization electric fields. Eastward polarization electric fields of similar to 2.5 mV/m within the flux tube caused an observed plasma bubble to drift vertically at a speed of 70 m/s. C1 MIT, Plasma Sci & Fus Ctr, Cambridge, MA 02139 USA. AF Res Lab, Hanscom AFB, MA 01731 USA. Arecibo Observ, Arecibo, PR 00613 USA. Polytech Univ, Farmingdale, NY 11731 USA. RP Lee, MC (reprint author), MIT, Plasma Sci & Fus Ctr, 77 Massachusetts Ave, Cambridge, MA 02139 USA. NR 15 TC 9 Z9 9 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD MAR 1 PY 1998 VL 25 IS 5 BP 579 EP 582 DI 10.1029/98GL00327 PG 4 WC Geosciences, Multidisciplinary SC Geology GA ZA533 UT WOS:000072373800001 ER PT J AU Huang, CY Burke, WJ Hardy, DA Gough, MP Olson, DG Gentile, LC Gilchrist, BE Bonifazi, C Raitt, WJ Thompson, DC AF Huang, CY Burke, WJ Hardy, DA Gough, MP Olson, DG Gentile, LC Gilchrist, BE Bonifazi, C Raitt, WJ Thompson, DC TI Cerenkov emissions of ion acoustic-like waves generated by electron beams emitted during TSS 1R SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SPACE-SHUTTLE AB During the Tethered Satellite System reflight the Spacecraft Particle Correlation Experiment detected fluxes of energetic electrons and ions that were simultaneously modulated at low frequencies during firings of both the fast pulsed electron gun (FPEG) and the electron generator assembly (EGA). The modulations have been interpreted as signatures of large-amplitude, ion acoustic-like waves excited in Cerenkov interactions between electron beams and ambient plasmas as the shuttle moved at supersonic speeds across the ionospheric magnetic field. We present examples of particle modulations observed during steady beam emissions. Measurements show that (1) most electron modulations were at frequencies of several hundred Hertz and (2) ions modulated at similar frequencies appeared at spectral energy peaks during shuttle negative charging events. Detection of modulated ion fluxes confirms the Cerenkov emission hypothesis. Observed frequency variations indicate that the EGA beam underwent more spatial spreading than the FPEG beam. C1 Boston Coll, Inst Sci Res, Chestnut Hill, MA 02167 USA. USAF, Res Lab, Hanscom AFB, MA 01731 USA. Univ Sussex, Ctr Space Sci, Brighton BN1 9QT, E Sussex, England. Univ Michigan, Space Phys Res Lab, Ann Arbor, MI 48109 USA. Agenzia Spaziale Italiana, I-00198 Rome, Italy. Utah State Univ, Ctr Atmospher & Space Sci, Logan, UT 84322 USA. RP Huang, CY (reprint author), Boston Coll, Inst Sci Res, 402 St Clements Hall,140 Commonwealth Ave, Chestnut Hill, MA 02167 USA. NR 10 TC 6 Z9 6 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD MAR 1 PY 1998 VL 25 IS 5 BP 721 EP 724 DI 10.1029/98GL00333 PG 4 WC Geosciences, Multidisciplinary SC Geology GA ZA533 UT WOS:000072373800038 ER PT J AU Manganaro, AM Will, MJ Bradley, MD Peckham, S Faulk-Eggleston, J Fish, M AF Manganaro, AM Will, MJ Bradley, MD Peckham, S Faulk-Eggleston, J Fish, M TI Benign keratotic squamous epithelial neoplasm of the palate: A unique lesion SO HEAD AND NECK-JOURNAL FOR THE SCIENCES AND SPECIALTIES OF THE HEAD AND NECK LA English DT Article DE trichoadenoma; trichoepithelioma AB Background. This case report describes a unique palatal tumor with features of a dermal neoplasm. Microscopically, the lesion appeared similar to a trichoepithelioma and trichoadenoma. Methods. Light microscopic and immunohistochemical studies were performed to arrive at the final diagnosis. Results. The lesion arose from the surface epithelium and had features of a dermal tumor. Conclusions. The case report describes a unique benign palatal neoplasm. (C) 1998 John Wiley & Sons, Inc. C1 Brooke Army Med Ctr, Dept Oral & Maxillofacial Surg Oral & Maxillofaci, Ft Sam Houston, TX 78234 USA. USA, Dent Corps, Washington, DC USA. USA, Med Corps, Washington, DC USA. USAF, Med Corps, Washington, DC USA. Brooke Army Med Ctr, Oral & Maxillofacial Surg Clin, Ft Sam Houston, TX 78234 USA. Brooke Army Med Ctr, Cytol Sect, Ft Sam Houston, TX 78234 USA. RP Manganaro, AM (reprint author), 14210 Silver Hollow, San Antonio, TX 78232 USA. NR 1 TC 2 Z9 2 U1 0 U2 0 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 1043-3074 J9 HEAD NECK-J SCI SPEC JI Head Neck-J. Sci. Spec. Head Neck PD MAR PY 1998 VL 20 IS 2 BP 175 EP 178 DI 10.1002/(SICI)1097-0347(199803)20:2<175::AID-HED12>3.0.CO;2-L PG 4 WC Otorhinolaryngology; Surgery SC Otorhinolaryngology; Surgery GA YV240 UT WOS:000071803400012 PM 9484950 ER PT J AU Gulley, ML Burton, MP Allred, DC Nicholls, JM Amin, MB Ro, JY Schneider, BG AF Gulley, ML Burton, MP Allred, DC Nicholls, JM Amin, MB Ro, JY Schneider, BG TI Epstein-Barr virus infection is associated with p53 accumulation in nasopharyngeal carcinoma SO HUMAN PATHOLOGY LA English DT Article DE nasopharyngeal carcinoma; Epstein-Barr virus; p53 ID NF-KAPPA-B; PREINVASIVE LESIONS; GENE; EXPRESSION; MUTATIONS; PROTEIN; CANCER; TRANSACTIVATOR; PROLIFERATION; INDUCTION AB Eight-three cases of nasopharyngeal carcinoma were evaluated for the presence of Epstein-Barr virus (EBV) infection in tumor cells by in situ hybridization to EBER1 transcripts, and for p53 expression by immunostains using the D07 antibody which detects native and mutant forms of the p53 protein. A highly significant association was found between EBV infection and p53 overexpression (P = .0004), with 77% of cases coexpressing both markers, This newly discovered association suggests that EBV is not an innocent bystander with respect to p53 accumulation. One possible mediator of the interaction between EBV and p53, viral BZLF1, was not colocalized. with p53 in these tumors, suggesting that BZLF1 is not the factor responsible for p53 accumulation. From an epidemiological standpoint, this series of cancers represents an international cohort in which cases from an endemic part of the world (Hong Kong) were examined alongside cases from the United Slates, where the disease is 50-fold less prevalent. The cancers from Hong Kong tended to be less differentiated and more frequently associated with EBV, suggesting that biological differences might underlie epidemiological variations in turner prevalence. Finally, we examined 18 potential;premalignant lesions of the surface epithelium of the nasopharynx. Although our numbers are small, our data suggest that p53 accumulation might precede EBV infection in the transition from metaplasia to carcinoma in situ. Further studies are needed to dissect the stepwise progression of nasopharyngeal carcinogenesis. Copyright (C) 1998 by W.B. Saunders Company. C1 Univ Texas, Hlth Sci Ctr, Dept Pathol, San Antonio, TX 78284 USA. Audie L Murphy Mem Vet Hosp, Dept Pathol, San Antonio, TX 78284 USA. Wilford Hall USAF Med Ctr, Dept Pathol, San Antonio, TX 78236 USA. Univ Hong Kong, Dept Pathol, Hong Kong, Hong Kong. Henry Ford Hosp, Dept Pathol, Detroit, MI 48202 USA. Univ Texas, Md Anderson Canc Ctr, Dept Pathol, Houston, TX 77030 USA. Louisiana State Univ, Med Ctr, Dept Pathol, New Orleans, LA 70112 USA. RP Gulley, ML (reprint author), Univ Texas, Hlth Sci Ctr, Dept Pathol, 7703 Floyd Curl Dr, San Antonio, TX 78284 USA. FU NCI NIH HHS [P30-CA54174] NR 41 TC 52 Z9 57 U1 0 U2 1 PU W B SAUNDERS CO PI PHILADELPHIA PA INDEPENDENCE SQUARE WEST CURTIS CENTER, STE 300, PHILADELPHIA, PA 19106-3399 USA SN 0046-8177 J9 HUM PATHOL JI Hum. Pathol. PD MAR PY 1998 VL 29 IS 3 BP 252 EP 259 DI 10.1016/S0046-8177(98)90044-2 PG 8 WC Pathology SC Pathology GA YZ606 UT WOS:000072270900009 PM 9496828 ER PT J AU Drummond, JD Fugate, RQ Christou, JC Hege, EK AF Drummond, JD Fugate, RQ Christou, JC Hege, EK TI Full adaptive optics images of asteroids Ceres and Vesta; Rotational poles and triaxial ellipsoid dimensions SO ICARUS LA English DT Article DE imaging; adaptive optics; asteroids; rotational poles; dimensions; Ceres; Vesta ID ITERATIVE BLIND DECONVOLUTION; SPECKLE INTERFEROMETRY; RANGE; ADS-9731; ALBEDO AB Adaptive optics (AO) images of asteroids Ceres and Vesta were obtained on September 18-20, 1993, with the 1.5-m telescope at the Starfire Optical Range of the USAF Phillips Laboratory located near Albuquerque, NM. The light source for higher-order wavefront correction was a Rayleigh laser beacon focused at a range of 10.5 km generated by a copper vapor laser. On April 27 and May 11, 1996, Vesta was again imaged, this time at its perihelic opposition using Vesta itself as the beacon for the AO. Images obtained at an effective wavelength of 0.85 mu m were analyzed with a new reconstruction technique, called parametric blind deconvolution. The technique allows fits for relevant parameters in the frequency domain, where the convolution of the asteroid ellipse with the variable Lorentz-shaped point spread function produced by the AO system during these observations can be separated into a multiplication of analytic functions. The triaxial ellipsoid dimensions and rotational pole (with a two-fold ambiguity) of Ceres were obtained from 17 images and found to be in excellent agreement with its 1983 stellar occultation outline (Millis et al., 1987, Icarus 72, 507-518) and the 1991 AO image produced by the COME-ON system (Saint-Pe et al., 1993, Icarus 105, 271-281). A similar analysis of eight images of Vesta in 1993, 19 images in April 1996, and 28 images in May 1996, and combined with results from four previous speckle interferometry (SI) sets, yield dimensions and a rotational pole in reasonable agreement with the Hubble Space Telescope's results (Thomas ef al. 1997). Differences may arise from a non-alignment between principal axes of inertia and the spin axis. The AO data from May 11, 1996, is of sufficient quality that Vesta's lightcurve can be decomposed into its cross-sectional area and surface brightness components, proving analytically that Vesta's lightcurve minimum is caused by a dark hemisphere. Combining the AO and SI observations with previous lightcurves yields a sidereal period of 0.22258874 days with an uncertainty of 4 in the last decimal place (3.5 ms) and shows that lightcurve minimum occurs 6 degrees before a maximum in cross-section area. (C) 1998 Academic Press. C1 USAF, Res Lab, Starfire Opt Range, Kirtland AFB, NM 87117 USA. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. RP Drummond, JD (reprint author), USAF, Res Lab, Starfire Opt Range, 3550 Aberdeen Ave SE, Kirtland AFB, NM 87117 USA. NR 37 TC 53 Z9 53 U1 0 U2 5 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0019-1035 J9 ICARUS JI Icarus PD MAR PY 1998 VL 132 IS 1 BP 80 EP 99 DI 10.1006/icar.1997.5882 PG 20 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA ZP811 UT WOS:000073790800005 ER PT J AU Cerny, CL Via, GD Ebel, JL DeSalvo, GC Quach, TK Bozada, CA Dettmer, RW Gillespie, JK Jenkins, TJ Pettiford, CI Sewell, JS Ehret, JE Merkel, K Wilson, A Lyke, J AF Cerny, CL Via, GD Ebel, JL DeSalvo, GC Quach, TK Bozada, CA Dettmer, RW Gillespie, JK Jenkins, TJ Pettiford, CI Sewell, JS Ehret, JE Merkel, K Wilson, A Lyke, J TI Xs-MET - A reduced complexity fabrication process using complementary heterostructure field effect transistors for analog, low power, space applications SO IEEE AEROSPACE AND ELECTRONIC SYSTEMS MAGAZINE LA English DT Article ID OHMIC CONTACTS; GAAS; TECHNOLOGY; RADIATION AB The requirements for space-based integrated circuit applications are defined with an emphasis on being radiation tolerant and low power consuming, Flexible analog signal processors (FASPs) are outlined as a means by which effective circuit designs can be utilized to perform a multitude of tasks, The development of complementary III-V technologies have been proven to meet the demands of the space environment, and have demonstrated the potential for frequency operation beyond 1 GHz using power supply voltages at or below 1.5 Volts. The novel fabrication process known as Xs-MET (pronounced kismet, which uses the Creek letter chi, X, and stands for Complementary Heterostructure Integrated Single Metal Transistor), is introduced as a manufacturing technique to be used in FASP design. The Xs-MET fabrication process is outlined with preliminary device results presented. An example of a FASP circuit design using Xs-MET is provided. Conclusions regarding the utilization of the Xs-MET process for FASPs are outlined with comments focusing on a space-based demonstration. C1 Wright Lab, Avion Directorate, Electron Devices Div, Patterson AFB, OH 45433 USA. USAF, Phillips Lab, Space Mission Technol Div, Kirtland AFB, NM 87117 USA. RP Wright Lab, Avion Directorate, Electron Devices Div, Patterson AFB, OH 45433 USA. NR 16 TC 0 Z9 0 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0885-8985 EI 1557-959X J9 IEEE AERO EL SYS MAG JI IEEE Aerosp. Electron. Syst. Mag. PD MAR PY 1998 VL 13 IS 3 BP 7 EP 14 DI 10.1109/62.659858 PG 8 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA ZA480 UT WOS:000072367500004 ER PT J AU Iaconis, C Wong, V Walmsley, IA AF Iaconis, C Wong, V Walmsley, IA TI Direct interferometric techniques for characterizing ultrashort optical pulses SO IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS LA English DT Article; Proceedings Paper CT Meeting on Ultrafast Optics CY 1997 CL MONTEREY, CALIFORNIA DE laser measurements; measurement; pulse characterization,; pulse measurements; ultrafast optics ID WIGNER DISTRIBUTION FUNCTION; FEMTOSECOND PULSES; PHASE; LIGHT AB The two-time nonstationary correlation function is defined and applied to the problem of characterizing pulses whose amplitude and phase vary randomly from pulse to pulse. Using a linear-systems approach developed in earlier work, four simple interferometric techniques for measuring this quantity are described and analyzed. We show that these four methods offer simple and direct algorithms for reconstructing the correlation function and, in the case of a single pulse or a coherent ensemble of pulses, return the electric field amplitude and phase. C1 Univ Rochester, Inst Opt, Rochester, NY 14627 USA. RP Iaconis, C (reprint author), USAF, Phillips Lab, PL LIDA, Kirtland AFB, NM 87117 USA. NR 14 TC 28 Z9 29 U1 2 U2 7 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1077-260X J9 IEEE J SEL TOP QUANT JI IEEE J. Sel. Top. Quantum Electron. PD MAR-APR PY 1998 VL 4 IS 2 BP 285 EP 294 DI 10.1109/2944.686734 PG 10 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA ZV019 UT WOS:000074260200017 ER PT J AU Bass, T Freyre, A Gruber, D Watt, G AF Bass, T Freyre, A Gruber, D Watt, G TI E-mail bombs and countermeasures: Cyber attacks on availability and brand integrity SO IEEE NETWORK LA English DT Article AB The simplicity of SMTP mail can be combined with the robustness of the sendmail MTA program and misused in numerous ways to create extraordinary and powerful e-mail bombs. These e-mail bombs can be launched in many different attack scenarios which can easily flood and shut down chains of SMTP mail servers. Sendmail-based SMTP mail relays also can be used covertly to distribute messages and files that could be very damaging to the integrity and brands of victims. This article discusses mail-bombing techniques, automated attack tools, and countermeasures. Also discussed is an actual Internet-based attack that was launched in 1997 on the Langly AFB SMTP e-mail infrastructure. The authors also present an analysis of the cyber attack, graphs illustrating the attack volume, and a statistical e-mail bomb early warning system. C1 SAIC, Ctr Informat Protect, Hampton, VA 23666 USA. USAF, Langley AFB, VA 23665 USA. RP Bass, T (reprint author), SAIC, Ctr Informat Protect, Hampton, VA 23666 USA. OI Bass, Tim/0000-0001-9368-6838 NR 21 TC 5 Z9 5 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0890-8044 J9 IEEE NETWORK JI IEEE Netw. PD MAR-APR PY 1998 VL 12 IS 2 BP 10 EP 17 DI 10.1109/65.681925 PG 8 WC Computer Science, Hardware & Architecture; Computer Science, Information Systems; Engineering, Electrical & Electronic; Telecommunications SC Computer Science; Engineering; Telecommunications GA ZT823 UT WOS:000074131200003 ER PT J AU Leahy, DJ Mooney, JM Alexander, MN Chi, MM Mil'shtein, S AF Leahy, DJ Mooney, JM Alexander, MN Chi, MM Mil'shtein, S TI Rapid, large area mapping of defect concentration in semiconductor wafers by infrared absorption SO INFRARED PHYSICS & TECHNOLOGY LA English DT Article ID GAAS; EL2 AB We report a fast, nondestructive method of mapping defect concentrations over large areas of semiconductor wafers. The method uses a platinum silicide staring focal plane array (FPA) camera to image wafers quickly and with high resolution in the near infrared band. The camera collects data simultaneously from 78,000 points on a 100 mm diameter wafer. For each point, the defect-related absorption coefficient was determined and converted to defect density. The entire process requires about 5 min. This method was demonstrated by measuring and mapping EL2 concentration in undoped semi-insulating liquid encapsulated Czochralski gallium arsenide wafers. (C) 1998 Elsevier Science B.V. C1 USAF, Rome Lab, Hanscom AFB, MA 01731 USA. Univ Lowell, Lowell, MA 01854 USA. RP Leahy, DJ (reprint author), USAF, Rome Lab, Hanscom AFB, MA 01731 USA. NR 14 TC 0 Z9 0 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1350-4495 J9 INFRARED PHYS TECHN JI Infrared Phys. Technol. PD MAR PY 1998 VL 39 IS 2 BP 83 EP 88 DI 10.1016/S1350-4495(97)00045-5 PG 6 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA ZR538 UT WOS:000073987600004 ER PT J AU Marshall, RJ Marshall, P AF Marshall, RJ Marshall, P TI A computational study of the reaction kinetics of methyl radicals with trifluorohalomethanes SO INTERNATIONAL JOURNAL OF CHEMICAL KINETICS LA English DT Article ID CF3BR; ENERGIES; METHANE; SILANE AB Ab initio calculations have been used to characterize the transition states for halogen abstraction by CH3 in reactions with CF4, CF3Cl, CF3Br, and CF3I (1-4). Geometries and frequencies were obtained at the HF/6-31G(d) and MP2 = full/6-31G(d) levels of theory, Energy barriers were computed via the Gaussian-2 methodology, and the results were employed in transition state theory analyses to obtain the rate constants over 298-2500 K. There is good accord with literature measurements in the approximate temperature range 360-500 K for reactions (2-4), and the-computed activation energies are accurate to within +/- 6 kJ mol(-1). Recommended rate constant expressions for use in combustion modeling are k(1) = 1.6 x 10(-19) (T/K)(2.41) exp(-3990 K/T), k(4) = 8.4 x 10(-20) (T/K)(2.34) exp(-5000 K/T), k(3) = 4.6 x 10(-19) (T/K)(2.05) exp(-3990 K/T), and k(4) = 8.3 x 10(-19) (T/K)(2.18) exp(-1870 K/T) cm(3) molecule(-1) s(-1). The results are discussed in the context of flame suppression chemistry. (C) 1998 John Wiley & Sons, Inc. C1 USAF, Ctr Computat Modeling Nonstruct Mat, Res Lab, Mat Directorate, Wright Patterson AFB, OH 45433 USA. Univ N Texas, Dept Chem, Denton, TX 76203 USA. RP Marshall, P (reprint author), USAF, Ctr Computat Modeling Nonstruct Mat, Res Lab, Mat Directorate, Wright Patterson AFB, OH 45433 USA. NR 26 TC 0 Z9 0 U1 0 U2 3 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0538-8066 J9 INT J CHEM KINET JI Int. J. Chem. Kinet. PD MAR PY 1998 VL 30 IS 3 BP 179 EP 184 PG 6 WC Chemistry, Physical SC Chemistry GA YZ563 UT WOS:000072266600002 ER PT J AU Prete, JJ Prestidge, BR Bice, WS Friedland, JL Stock, RG Grimm, PD AF Prete, JJ Prestidge, BR Bice, WS Friedland, JL Stock, RG Grimm, PD TI A survey of physics and dosimetry practice of permanent prostate brachytherapy in the United States SO INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS LA English DT Article; Proceedings Paper CT 19th Annual Meeting of the American-Brachytherapy-Society CY MAY 20, 1997 CL PALM BEACH, FLORIDA SP Amer Brachytherapy Soc DE prostate brachytherapy; physics and dosimetry practice; survey ID IMPLANTATION; CARCINOMA; MORBIDITY; CANCER AB Purpose: To obtain data with regard to current physics and dosimetry practice in transperineal interstitial permanent prostate brachytherapy (TIPPB) in the U.S. by conducting a survey of institutions performing this procedure with the greatest frequency. Methods and Materials: Seventy brachytherapists with the greatest volume of TIPPB cases in 1995 in the U.S. were surveyed. The four-page comprehensive questionnaire included questions on both clinical and physics and dosimetry practice. Individuals not responding initially were sent additional mailings and telephoned. Physics and dosimetry practice summary statistics are reported. Clinical practice data is reported separately. Results: Thirty-five (50%) surveys were returned. Participants included 29 (83%) from the private sector and 6 (17%) from academic programs. Among responding clinicians, I-125 (89%) is used with greater frequency than Pd-103 (83%). Many use both (71%). Most brachytherapists perform preplans (86%), predominately employing ultrasound imaging (85%). Commercial treatment planning systems are used more frequently (75%) than in-house systems (25%). Preplans take 2.5 h (avg.) to perform and are most commonly performed by a physicist (69%). A wide range of apparent activities (mCi) is used for both I-125 (0.16-1.00, avg. 0.41) and Pd-103 (0.50-1.90, avg. 1.32). Of those assaying sources (71%), the range in number assayed (1 to all) and maximum accepted difference from vendor stated activity (2-20%) varies greatly. Most respondents feel that the manufacturers criteria for source activity are sufficiently stringent (88%); however, some report that vendors do not always meet their criteria (44%). Most postimplant dosimetry imaging occurs on day 1 (41%) and consists of conventional x-rays (83%), CT (63%), or both (46%). Postimplant dosimetry is usually performed by a physicist (72%), taking 2 h (avg.) to complete, Calculational formalisms and parameters vary substantially. At the time of the survey, few institutions have adopted AAPM TG-43 recommendations (21%). Only half (50%) of those not using TG-43 indicated an intent to do so in the future. Calculated doses at 1 cm from a single 1 mCi apparent activity source permanently implanted varied significantly. For I-125, doses calculated ranged from 13.08-40.00 Gy and for Pd-103, from 3.10 to 8.70 Gy. Conclusion: While several areas of current physics and dosimetry practice are consistent among institutions, treatment planning and dose calculation techniques vary considerably. These data demonstrate a relative lack of consensus with regard to these practices. Furthermore, the wide variety of calculational techniques and benchmark data lead to calculated doses which vary by clinically significant amounts. It is apparent that the lack of standardization with regard to treatment planning and dose calculation practice in TIPPB must be addressed prior to performing any meaningful comparison of clinical results between institutions. C1 Wilford Hall USAF Med Ctr, Radiat Oncol PSRT, Dept Radiat Oncol, Lackland AFB, TX 78236 USA. Univ Texas, Hlth Sci Ctr, Dept Radiol, Div Radiol Sci, San Antonio, TX 78284 USA. RP Prete, JJ (reprint author), Wilford Hall USAF Med Ctr, Radiat Oncol PSRT, Dept Radiat Oncol, 2200 Bergquist Dr,Suite 1, Lackland AFB, TX 78236 USA. NR 15 TC 35 Z9 35 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0360-3016 J9 INT J RADIAT ONCOL JI Int. J. Radiat. Oncol. Biol. Phys. PD MAR 1 PY 1998 VL 40 IS 4 BP 1001 EP 1005 DI 10.1016/S0360-3016(97)00901-2 PG 5 WC Oncology; Radiology, Nuclear Medicine & Medical Imaging SC Oncology; Radiology, Nuclear Medicine & Medical Imaging GA ZC991 UT WOS:000072639900031 PM 9531387 ER PT J AU Wald, C AF Wald, C TI Transforming defense SO ISSUES IN SCIENCE AND TECHNOLOGY LA English DT Editorial Material C1 USAF, Washington, DC 20330 USA. RP Wald, C (reprint author), USAF, Washington, DC 20330 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0748-5492 J9 ISSUES SCI TECHNOL JI Issues Sci. Technol. PD SPR PY 1998 VL 14 IS 3 BP 9 EP 10 PG 2 WC Engineering, Multidisciplinary; Engineering, Industrial; Multidisciplinary Sciences; Social Issues SC Engineering; Science & Technology - Other Topics; Social Issues GA ZH151 UT WOS:000073077900006 ER PT J AU Blake, WB AF Blake, WB TI Development of the C-17 formation airdrop element geometry SO JOURNAL OF AIRCRAFT LA English DT Article; Proceedings Paper CT AIAA Atmospheric Flight Mechanics Conference CY AUG 11-13, 1997 CL NEW ORLEANS, LOUISIANA SP Amer Inst Aeronaut & Astronaut ID MODEL; DECAY AB The analysis and tests that established a three-ship C-17 element geometry suitable for formation airdrop operations at night are discussed. The objective is to avoid jumpers encountering vortices generated by aircraft upstream. Candidate formation geometries were judged using a vortex tracking code that estimated the closest lateral proximity between a vortex and a jumper for a given wind condition. The initial formation geometry underwent two changes during the course of the test as a result of the introduction of tolerance boxes for aircraft position and vortex encounters that occurred during mannequin trials. An echelon geometry 6000 ft Long and 1500 ft wide was ultimately adopted. In 101 passes over the drop zone, 1349 mannequins and 1251 personnel were dropped from this formation geometry without a vortex encounter. C1 USAF, Res Lab, Wright Patterson AFB, OH 45433 USA. RP Blake, WB (reprint author), USAF, Res Lab, Wright Patterson AFB, OH 45433 USA. NR 19 TC 3 Z9 3 U1 0 U2 1 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0021-8669 J9 J AIRCRAFT JI J. Aircr. PD MAR-APR PY 1998 VL 35 IS 2 BP 175 EP 182 DI 10.2514/2.2298 PG 8 WC Engineering, Aerospace SC Engineering GA ZE540 UT WOS:000072803600002 ER PT J AU Lin, KC Sisti, A Chow, L AF Lin, KC Sisti, A Chow, L TI Study on crowded two-dimensional airspace - Self-organized criticality SO JOURNAL OF AIRCRAFT LA English DT Article ID TRAFFIC JAMS; SIMULATION AB A crowded airspace involves large numbers of airplanes interacting with each other. In general, the dynamic behavior of the system is quite complex and conventional mathematical modeling is difficult. Here, a generic air traffic model is used to investigate the application of the notion of self-organized criticality. An example of a crowded two-dimensional airspace near an airport is studied. The results show that a crowded air traffic system exhibits the characteristics of self-organized criticality. C1 Inst Simulat & Training, Orlando, FL 32826 USA. USAF, Res Lab, IFSB, I-13441 Rome, Italy. Univ Cent Florida, Dept Phys, Orlando, FL 32816 USA. RP Lin, KC (reprint author), Inst Simulat & Training, 3280 Progress Dr, Orlando, FL 32826 USA. NR 17 TC 3 Z9 3 U1 1 U2 1 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0021-8669 J9 J AIRCRAFT JI J. Aircr. PD MAR-APR PY 1998 VL 35 IS 2 BP 301 EP 306 DI 10.2514/2.2300 PG 6 WC Engineering, Aerospace SC Engineering GA ZE540 UT WOS:000072803600021 ER PT J AU Lena, MR Klug, JC Sun, CT AF Lena, MR Klug, JC Sun, CT TI Composite patches as reinforcements and crack arrestors in aircraft structures SO JOURNAL OF AIRCRAFT LA English DT Article AB The application of adhesively bonded composite patches as reinforcements and crack arrestors for a multisite damaged aircraft structure is investigated. Experiments are performed to test the ability of a bonded composite reinforcement to prevent cracks from coalescing. With a finite element model developed for composite patch repairs, the effect of thermal residual stresses on the stress-intensity factor and the resulting fatigue crack growth rate is demonstrated. An effective thermal stress is estimated by comparing experimental results with model predictions. Reinforcement for a multiple-site damage situation is analyzed by modeling an infinite row of closely spaced cracked rivet holes. The composite reinforcement is shown to dramatically reduce the stress-intensity factor, increase fatigue life, and protect against catastrophic failure. C1 Purdue Univ, Sch Aeronaut & Astronaut, W Lafayette, IN 47906 USA. RP Lena, MR (reprint author), USAF, Wright Patterson AFB, OH 45433 USA. NR 9 TC 21 Z9 21 U1 0 U2 3 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0021-8669 J9 J AIRCRAFT JI J. Aircr. PD MAR-APR PY 1998 VL 35 IS 2 BP 318 EP 323 DI 10.2514/2.2302 PG 6 WC Engineering, Aerospace SC Engineering GA ZE540 UT WOS:000072803600023 ER PT J AU Kolonay, RM Yang, HTY AF Kolonay, RM Yang, HTY TI Static aeroelastic effects on a transonic indicial response wing flutter calculation SO JOURNAL OF AIRCRAFT LA English DT Article; Proceedings Paper CT AIAA/USAF/NASA/ISSMO 6th Symposium on Multidisciplinary Analysis and Optimization CY SEP 04-06, 1996 CL BELLEVUE, WASHINGTON SP AIAA, USAF, NASA, ISSMO C1 USAF, Res Lab, Struct Div, Flight Dynam Directorate, Wright Patterson AFB, OH 45433 USA. Univ Calif Santa Barbara, Dept Mech & Aerosp Engn, Santa Barbara, CA 93106 USA. RP Kolonay, RM (reprint author), USAF, Res Lab, Struct Div, Flight Dynam Directorate, Wright Patterson AFB, OH 45433 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0021-8669 J9 J AIRCRAFT JI J. Aircr. PD MAR-APR PY 1998 VL 35 IS 2 BP 339 EP 341 DI 10.2514/2.7578 PG 3 WC Engineering, Aerospace SC Engineering GA ZE540 UT WOS:000072803600026 ER PT J AU Nathan, V AF Nathan, V TI Optical absorption in Hg1-xCdxTe SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID GAP AB The theory of optical absorption due to interband transitions in direct-gap semiconductors is revisited. An analytical expression for the linear absorption coefficient in narrow-gap semiconductors is obtained by including the nonparabolic band structure due to Keldysh [Sov. Phys.-JETP 6, 763 (1958)] and Burstein-Moss shift. Numerical results are obtained for Hg1-xCdxTe for several values of x and temperature, and compared with recent experimental data. The agreement is found to be good. C1 USAF, Res Lab, VSSS, Kirtland AFB, NM 87117 USA. RP Nathan, V (reprint author), USAF, Res Lab, VSSS, 3550 Aberdeen Ave SE, Kirtland AFB, NM 87117 USA. NR 16 TC 8 Z9 10 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAR 1 PY 1998 VL 83 IS 5 BP 2812 EP 2814 DI 10.1063/1.367040 PG 3 WC Physics, Applied SC Physics GA YZ942 UT WOS:000072310700060 ER PT J AU Affleck, PJ Waisel, DB Cusick, JM Van Decar, T AF Affleck, PJ Waisel, DB Cusick, JM Van Decar, T TI Recall of risks following labor epidural analgesia SO JOURNAL OF CLINICAL ANESTHESIA LA English DT Article DE analgesia; labor, obstetrical; anesthesia risks; informed consent; pregnancy; prenatal care ID INFORMED CONSENT; ANESTHESIA; SURGERY AB Study Objective: To ascertain patients' recall of the risks of labor epidural analgesia from a discussion of informed consent during active labor. Design: Survey analysis following an intervention. Setting: Labor and delivery unit of a tertiary-care teaching hospital. Patients: 101 ASA physical status I and II parturients in active labor. Interventions: Patients were given a standardized discussion of the risks of labor epidural analgesia. Measurements and Main Results: Within 24 hours of the informed consent discussion, patients were first asked to recall risks, and then asked to identify risks from a true and false list. Patients recalled 2.0 +/- 1.3 risks (mean +/- SD), with 12% recalling at least four risks, 37% recalling at least three risks, 66% recalling at least two risks, and 87% recalling at least one risk. There was no difference in level of recall between primiparas and multiparas, or in patients with mild and moderate pain scores versus those patients with severe pain scores. Conclusions: Recall of risks by parturients is similar to the recall of risks by other patients, and if does not appear to be affected by parity or the reported level of pain. (C) 1998 by Elsevier Science Inc. C1 Wilford Hall USAF Med Ctr, Anesthesia & Operat Serv, Lackland AFB, TX 78236 USA. RP Affleck, PJ (reprint author), POB 9845, Nellis AFB, NV 89191 USA. OI Waisel, David/0000-0002-5307-4092 NR 15 TC 22 Z9 22 U1 0 U2 0 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 0952-8180 J9 J CLIN ANESTH JI J. Clin. Anesth. PD MAR PY 1998 VL 10 IS 2 BP 141 EP 144 DI 10.1016/S0952-8180(97)00258-4 PG 4 WC Anesthesiology SC Anesthesiology GA ZA801 UT WOS:000072403200011 PM 9524900 ER PT J AU Greer, JM Palazotto, AN AF Greer, JM Palazotto, AN TI Tire contact using two-dimensional finite elements SO JOURNAL OF ENGINEERING MECHANICS-ASCE LA English DT Article ID COMPOSITE PLATES; FORMULATION; SHELLS; MODEL AB The problem of static contact between a tire and a nondeformable surface is explored with two-dimensional shell finite elements. The tire is treated as a composite shell, due to its nylon-corded rubber ply (laminated) construction. In the actual tire, the ply orientation angles, numbers of plies, ply thicknesses, and even the ply moduli change in the meridional direction (the direction perpendicular to the "rolling" direction). Moreover, the moduli of the materials used in construction span several orders of magnitude (isotropic rubber tread, nylon-corded rubber plies, and steel bead wires). These features present a formidable challenge to analyzing the tire with two-dimensional finite element codes. In the current work, quasi-three-dimensional behavior of the tire in static contact with a flat surface is generated through the finite element technique. The two-dimensional finite elements include the effects of transverse shear warping and thickness stretching, and use the Jaumann (local engineering) stress measures. A local and layer-wise displacement field is used to describe the behavior of the shell away from the reference surface. In contrast to stress-resultant models, this technique allows estimation of stresses and strains in individual plies, including interlaminar shea and peeling stresses. C1 Wright Lab, Flight Dyn Directorate, Wright Patterson AFB, OH 45433 USA. AF Inst Technol, Dept Astronaut & Aeronaut, Wright Patterson AFB, OH USA. RP Greer, JM (reprint author), Wright Lab, Flight Dyn Directorate, Wright Patterson AFB, OH 45433 USA. NR 37 TC 0 Z9 0 U1 1 U2 1 PU ASCE-AMER SOC CIVIL ENGINEERS PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 USA SN 0733-9399 J9 J ENG MECH-ASCE JI J. Eng. Mech.-ASCE PD MAR PY 1998 VL 124 IS 3 BP 348 EP 357 PG 10 WC Engineering, Mechanical SC Engineering GA YX291 UT WOS:000072025500013 ER PT J AU Webster, AD AF Webster, AD TI Excavation of a Vietnam-era aircraft crash site: Use of cross-cultural understanding and dual forensic recovery methods SO JOURNAL OF FORENSIC SCIENCES LA English DT Article DE forensic science; forensic anthropology; emic viewpoint; dual methods; human remains recovery AB The excavation of a 23 year-old aircraft crash site in the Socialist Republic of Vietnam and the transformational processes preceding its excavation in 1995-1996 are detailed. The history of the site involved an initial catastrophic event, with subsequent reclamation and disturbances. Ultimately, a recovery effort by a joint U.S, team from the Central Identification Laboratory, Hawaii (CILHI), Joint Task Force-Full Accounting (JTF-FA) and a Socialist Republic of Vietnam contingent yielded numerous human remains, personal effects, and life support items from the crash site. This case study should be of interest to the increasing number of forensic anthropologists who carry out work in international contexts. The application of forensic anthropology in human rights abuse cases, for example in Rwanda, Argentina, and Bosnia, provide examples of such cross-cultural endeavors. Cultural factors act in the development of a site and should not be overlooked as significant taphonomic agents. The approach that an indigenous person takes to a crash site or mass grave may be quite different from our own approach, involving Western science. Holland, Anderson, and Mann (1) describe the postmortem alteration of exhumed and/or curated bone caused by indigenous Southeast Asian peoples; the examples provided by these authors demonstrate how culture affects the treatment of what we would call "evidence." The international nature of an incident can add complicating "filters" to the reconstruction of events, since reclamation responses by indigenous people vary according to their interpretations of the scene. An investigating forensic anthropologist needs to understand the emic viewpoint (the insider's view), as cultural anthropologists do, when attempting to recover and reconstruct such an incident. In response to the cultural (and natural) taphonomic agents at work on such a site, the use of dual forensic recovery methods-simultaneously treating the investigation scene like an aircraft crash and a clandestine burial site-is advised. Employing a flexible set of methods will allow for maximal recovery of evidence. C1 USA, Cent Identificat Lab, Hickam AFB, HI USA. RP Webster, AD (reprint author), 310 Worchester Ave, Hickam AFB, HI 96853 USA. NR 13 TC 12 Z9 12 U1 0 U2 2 PU AMER SOC TESTING MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DR, W CONSHOHOCKEN, PA 19428-2959 USA SN 0022-1198 J9 J FORENSIC SCI JI J. Forensic Sci. PD MAR PY 1998 VL 43 IS 2 BP 277 EP 283 PG 7 WC Medicine, Legal SC Legal Medicine GA ZE009 UT WOS:000072748000003 PM 9544536 ER PT J AU Keskinen, MJ Ossakow, SL Basu, S Sultan, PJ AF Keskinen, MJ Ossakow, SL Basu, S Sultan, PJ TI Magnetic-flux-tube-integrated evolution of equatorial ionospheric plasma bubbles SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID RAYLEIGH-TAYLOR INSTABILITY; SPREAD-F; NONLINEAR EVOLUTION; STEEPENED STRUCTURES; NEUTRAL WINDS; GRAVITY-WAVES; LATITUDE; REGION; DEPLETIONS; MODEL AB The nonlinear evolution of plasma bubbles in the equatorial ionosphere has been computed using an inhomogeneous magnetic-flux-tube-integrated model. We find that plasma bubbles develop in a fundamentally different manner with northern and southern hemispheric coupling as opposed to their evolution without coupling. Bubble density and electric field signatures derived from the numerical simulations are shown to be in qualitative agreement with recent satellite observations. C1 USAF, Res Lab, Hanscom AFB, MA USA. USN, Res Lab, Div Plasma Phys, Charged Particle Phys Branch, Washington, DC 20375 USA. RP Keskinen, MJ (reprint author), USN, Res Lab, Div Plasma Phys, Charged Particle Phys Branch, Washington, DC 20375 USA. NR 37 TC 42 Z9 42 U1 2 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD MAR 1 PY 1998 VL 103 IS A3 BP 3957 EP 3967 DI 10.1029/97JA02192 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA ZA782 UT WOS:000072401200002 ER PT J AU Kuo, SP Faith, J Lee, MC Kossey, P AF Kuo, SP Faith, J Lee, MC Kossey, P TI Numerical comparison of two schemes for the generation of ELF and VLF waves in the VHF heater-modulated polar electrojet SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID AURORAL ELECTROJET; RADIATION; FACILITY; RANGE AB Generation of ELF and VLF waves in the HF heater modulated polar electrojet is numerically studied. Illuminated by an amplitude modulated HF heater, the electron temperature of the electrojet is modulated accordingly. This, in turn, causes the modulation of the conductivity and thus the current of the electrojet. Emissions are then produced at the modulation frequency and its harmonics. The present work extends the previous one on a thermal instability to its nonlinear saturation regime. Two heater modulation schemes are considered. One modulates the heater by a rectangular periodic pulse. The other one uses two overlapping heater waves (beat wave scheme) having a frequency difference equal to the desired modulation frequency. It is essentially equivalent to a sinusoidal amplitude modulation. The nonlinear evolutions of the generated ELF and VLF waves are determined numerically. Their spectra are also evaluated. The results show that the signal quality of the second (beat wave) scheme is better. The field intensity of the emission at the fundamental modulation frequency is found to increase with the modulation frequency, consistent with the Tromso observations. C1 MIT, Plasma Sci & Fus Ctr, Cambridge, MA 02139 USA. USAF, Phillips Lab, Hanscom AFB, MA 01731 USA. TRW Co Inc, Space & Elect Grp, Redondo Beach, CA 90278 USA. Polytech Univ, Weber Res Inst, Farmingdale, NY 11735 USA. RP Kuo, SP (reprint author), Polytech Univ, Weber Res Inst, Route 110, Farmingdale, NY 11735 USA. NR 25 TC 14 Z9 14 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD MAR 1 PY 1998 VL 103 IS A3 BP 4063 EP 4069 DI 10.1029/97JA02535 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA ZA782 UT WOS:000072401200011 ER PT J AU Schumacher, C Khargonekar, PP AF Schumacher, C Khargonekar, PP TI Missile autopilot designs using H-infinity control with gain scheduling and dynamic inversion SO JOURNAL OF GUIDANCE CONTROL AND DYNAMICS LA English DT Article ID TRANSFORMATIONS; AIRCRAFT; FLIGHT AB Two nonlinear controller designs are presented for a bank-to-turn, air-to-air missile. The first controller is a gain-scheduled H-infinity, design, and the second is a nonlinear dynamic inversion design using a two-timescale separation, We carried out a number of time- and frequency-domain analysis procedures on the resulting designs and tested their performance on a nonlinear simulation of the missile. We compared the controller designs for nominal performance, robustness to uncertainties in the aerodynamic coefficients, and sensitivity to measurement noise, The dynamic inversion controller was found to be significantly less robust to aerodynamic uncertainty, Using a mu-analysis test on a linearization of the closed-loop dynamics with the dynamic inversion controller, we were able to find a destabilizing aerodynamic uncertainty for the full nonlinear system. C1 Univ Michigan, Dept Aerosp Engn, Ann Arbor, MI 48109 USA. Univ Michigan, Dept Elect Engn & Comp Sci, Ann Arbor, MI 48109 USA. RP Schumacher, C (reprint author), USAF, Res Lab, Flight Dynam Directorate, Wright Patterson AFB, OH 45433 USA. EM coreys@falcon.flight.wpafb.af.mil; pramod@eecs.umich.edu NR 17 TC 28 Z9 34 U1 0 U2 3 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0731-5090 J9 J GUID CONTROL DYNAM JI J. Guid. Control Dyn. PD MAR-APR PY 1998 VL 21 IS 2 BP 234 EP 243 DI 10.2514/2.4248 PG 10 WC Engineering, Aerospace; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA ZA178 UT WOS:000072336800005 ER PT J AU Thurman, RT Trumble, TE Hanel, DP Tencer, AF Kiser, PK AF Thurman, RT Trumble, TE Hanel, DP Tencer, AF Kiser, PK TI Two-, four-, and six-strand zone II flexor tendon repairs: An in situ biomechanical comparison using a cadaver model SO JOURNAL OF HAND SURGERY-AMERICAN VOLUME LA English DT Article AB A dynamic in vitro model of zone II flexor tendon repair was used to compare gliding resistance, gap formation, and ultimate strength of the 2-, 4-, and 6-strand repair techniques. Each of 12 hands was mounted to a loading frame with 3 flexor tendons attached to individual pneumatic cylinders. A spring attached to a pin through the distal end of each digit provided a 1.25-kg resistance force. The force required to flex each proximal interphalangeal joint to 90 degrees was determined. Following this, the tendons were sectioned and each was repaired using a different technique so that each specimen acted as its own control. The 2- and 4-strand core sutures were placed using a suture interlock technique with radial and ulnar grasping purchase of the tendon on each side of the transverse part of the repair. Each repair was accomplished using a single care stitch with the knot buried between the tendon ends. The 4-strand repair involved an additional horizontal mattress suture with the knot buried. Repair of the dorsal side of the tendon was performed followed by core suture placement. The palmar portion of the peripheral locking suture was completed after core suture placement. Following repair, each hand was remounted on the frame and cycled 1,000 times. After cyclic loading, the resulting gap between the repaired ends of each tendon was measured, the tendons were removed from the hand, and each was loaded to failure in tension. All tendon repairs showed a small, but not statistically significant, increase in gliding resistance after reconstruction. The 2-strand repair had significantly greater gap formation after cyclic loading (mean gap, 2.75 mm) than either the 4-strand (0.30 mm) or 6-strand (0.31 mm) repair. The tensile strength of the 6-strand repair (mean, 78.7 N) was significantly greater than either the 4-strand (means, 43.0 N) or 2-strand (mean, 33.9 N) repair. Copyright (C) 1998 by the American Society for Surgery of the Hand. C1 Wilford Hall USAF Med Ctr, Dept Plast Surg, Lackland AFB, TX 78236 USA. RP Tencer, AF (reprint author), Univ Washington, Harborview Med Ctr, Dept Orthoped, Box 359798,325 9th Ave, Seattle, WA 98104 USA. NR 17 TC 86 Z9 88 U1 0 U2 5 PU CHURCHILL LIVINGSTONE INC MEDICAL PUBLISHERS PI PHILADELPHIA PA CURTIS CENTER, INDEPENDENCE SQUARE WEST, PHILADELPHIA, PA 19106-3399 USA SN 0363-5023 J9 J HAND SURG-AM JI J. Hand Surg.-Am. Vol. PD MAR PY 1998 VL 23A IS 2 BP 261 EP 265 PG 5 WC Orthopedics; Surgery SC Orthopedics; Surgery GA ZG173 UT WOS:000072974400012 PM 9556266 ER PT J AU MacLeod, MA AF MacLeod, MA TI The spherical curl transform of a linear force-free magnetic field SO JOURNAL OF MATHEMATICAL PHYSICS LA English DT Article ID RADON-TRANSFORM; SPHEROMAK; MODELS; CLOUDS AB The description of linear force-free magnetic fields in terms of the Moses eigenfunctions of the curl operator begun previously is here completed by the derivation of a general expression for the held's spherical curl transform. This enables the transform space representation of a given field to be determined and compared with that of other fields, assisting the analysis and classification of this type of magnetic field as well as providing a basis for generalization. The result obtained gives the spherical curl transform as a weighted projection of the vector Radon transform of the field on the appropriate curl eigenvector. The process is exemplified by the determination of the transforms of three fields: the simplest force-free magnetic field, and the Lundquist and classical spheromak fields. The latter two are both of interest as models of the magnetic fields of solar magnetic clouds, while the classical spheromak field is relevant to the design of nuclear fusion reactors as well. The use of the transform in generalizing the Lundquist field is briefly discussed. As before, all results apply equally well to the description of the Trkalian subset of Beltrami fields in fluid dynamics. (C) 1998 American Institute of Physics. C1 USAF, Res Lab, Bedford, MA 01731 USA. RP MacLeod, MA (reprint author), USAF, Res Lab, Bedford, MA 01731 USA. NR 25 TC 3 Z9 3 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0022-2488 J9 J MATH PHYS JI J. Math. Phys. PD MAR PY 1998 VL 39 IS 3 BP 1642 EP 1658 DI 10.1063/1.532305 PG 17 WC Physics, Mathematical SC Physics GA ZA029 UT WOS:000072321000026 ER PT J AU Wainner, RS Hasz, M AF Wainner, RS Hasz, M TI Management of acute calcific tendinitis of the shoulder SO JOURNAL OF ORTHOPAEDIC & SPORTS PHYSICAL THERAPY LA English DT Article DE calcific tendinitis; shoulder; treatment AB Calcific deposits located within the tendons of the rotator cuff are frequently seen in patients presenting with shoulder pain. The pathogenesis of calcific tendinitis and the optimum management of patients presenting with acute symptoms are unclear. This paper reviews the incidence, proposed etiologies, and a unique treatment approach of rotator cuff calcific tendinitis. A case report of a patient with acute calcific tendinitis and subsequent shoulder motion and strength deficits is presented. A rational evaluation and treatment plan is outlined, which includes management and posttreatment changes, and radiographic findings are discussed. A team-management approach by physical therapy and orthopaedics services is emphasized. C1 Univ Pittsburgh, Sch Hlth & Rehabil Sci, Pittsburgh, PA 15260 USA. N Virginia Spine Inst, Reston, VA USA. USAF, Washington, DC 20330 USA. RP Wainner, RS (reprint author), 155 Ridgewood Dr, Freedom, PA 15042 USA. NR 28 TC 13 Z9 13 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 USA SN 0190-6011 J9 J ORTHOP SPORT PHYS JI J. Orthop. Sports Phys. Ther. PD MAR PY 1998 VL 27 IS 3 BP 231 EP 237 PG 7 WC Orthopedics; Rehabilitation; Sport Sciences SC Orthopedics; Rehabilitation; Sport Sciences GA YZ058 UT WOS:000072216000007 PM 9513869 ER PT J AU Fuller, RP Wu, PK Nejad, AS Schetz, JA AF Fuller, RP Wu, PK Nejad, AS Schetz, JA TI Comparison of physical and aerodynamic ramps as fuel injectors in supersonic flaw SO JOURNAL OF PROPULSION AND POWER LA English DT Article ID FLOWS; JETS AB An experimental investigation was conducted to compare the supersonic mixing performance of a novel flush-wall aerodynamic ramp injector with that of a physical ramp injector, The aerodynamic ramp injector consists of nine hush-wall jets arranged to produce fuel-vortex interactions for mixing enhancement in a supersonic crossflow. Test conditions included a Mach 2.0 crossflow of air with a Reynolds number of 3.63 x 10(7) per meter and helium injection with jet-to-freestream momentum flux ratios of 1.0 and 2.0, Conventional probing techniques, including species composition sampling, were employed to interrogate the flowfield at several downstream locations, Results show that with increasing jet momentum the aeroramp exhibited a significant increase in fuel penetration, whereas the physical ramp showed no discernible change, The near-field mixing of the aeroramp was superior to that of the physical ramp; however, the physical ramp reaches a fully mixed condition at approximately half the distance of the aeroramp, As the jet momentum was increased, the far-field mixing performance of the aeroramp approached that of the physical ramp, In all cases the total pressure loss incurred with the aeroramp was Less than that caused by the physical ramp, For both injectors the total pressure loss decreased with increasing jet momentum, It was concluded that, although physical ramps may provide better far-field mixing, properly designed flush-wall injection can provide comparable mixing performance while avoiding the practical problems associated with an intrusive geometry in a scramjet combustor. C1 Taitech Inc, Wright Patterson AFB, OH 45433 USA. USAF, Res Lab, Aero Prop & Power Directorate, Expt Res Branch POPT, Wright Patterson AFB, OH 45433 USA. Virginia Polytech Inst & State Univ, Dept Aerosp & Ocean Engn, Blacksburg, VA 24061 USA. RP Fuller, RP (reprint author), Taitech Inc, 2372 Lakeview Dr,Suite H, Wright Patterson AFB, OH 45433 USA. EM fullerrp@possum.appl.wpafb.af.mil NR 40 TC 34 Z9 40 U1 0 U2 6 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0748-4658 J9 J PROPUL POWER JI J. Propul. Power PD MAR-APR PY 1998 VL 14 IS 2 BP 135 EP 145 DI 10.2514/2.5278 PG 11 WC Engineering, Aerospace SC Engineering GA ZB675 UT WOS:000072496300002 ER PT J AU Wu, PK Kirkendall, KA Fuller, RP Nejad, AS AF Wu, PK Kirkendall, KA Fuller, RP Nejad, AS TI Spray structures of liquid jets atomized in subsonic crossflows SO JOURNAL OF PROPULSION AND POWER LA English DT Article ID ATOMIZATION; STREAM; FLOW AB The structures of spray plumes from 0.5-mm waterjets injected into a subsonic crossflow were experimentally investigated using phase Doppler particle anemometry, Droplet size, axial velocity, and volume nux were measured across the spray plume at several axial distances downstream of the injector exit, Results indicate that large droplets can be found in the central portion of the spray plume for cases with small liquid/air momentum flux ratios and in which the momentum exchange between column waves and the airstream is significant. For cases with large-momentum flux ratios, the droplet size distribution exhibits a concave-layered structure, with the peak on the centerline and large droplets at the top, Droplets were found to concentrate in a small area within the spray plume, which indicates that the liquid mass distribution is not uniform. The height of the maximum volume flux locations, an indicator of the location of the highest concentration of droplets, was measured and correlated with momentum flux ratios and axial distances, It was found that more droplets are distributed toward the upper portion of the spray plume for larger momentum flux ratios, Spray penetration, spray width, penetration-to-width ratio, and spray cross-sectional area were also found to increase with the momentum flux ratio. C1 Taitech Inc, Dayton, OH 45440 USA. USAF, Res Lab, Aero Prop & Power Directorate, Wright Patterson AFB, OH 45433 USA. RP Wu, PK (reprint author), Kaiser Marquardt, 16555 Saticoy St, Van Nuys, CA 91406 USA. NR 27 TC 74 Z9 83 U1 0 U2 18 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0748-4658 J9 J PROPUL POWER JI J. Propul. Power PD MAR-APR PY 1998 VL 14 IS 2 BP 173 EP 182 DI 10.2514/2.5283 PG 10 WC Engineering, Aerospace SC Engineering GA ZB675 UT WOS:000072496300007 ER PT J AU Uy, OM Benson, RC Erlandson, RE Boies, MT Silver, DM Lesho, JC Green, BD Galica, GE Wood, BE Hall, DF AF Uy, OM Benson, RC Erlandson, RE Boies, MT Silver, DM Lesho, JC Green, BD Galica, GE Wood, BE Hall, DF TI Midcourse space experiment contamination measurement during cryogen phase SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article ID EARLY OPERATIONS PHASE; MASS-SPECTROMETER; MSX AB In-orbit measurements with contamination-monitoring instruments were used to validate the Midcourse Space Experiment contamination model and to investigate the phenomenon of molecular and particle generation in space. Measurements from the first orbit contact through the first 10 months showed water vapor as the largest gaseous species, with argon gas from a venting source important only during the first week in orbit. Simple reporting tools were used for rapid assessments of the spacecraft environment during early operations. The contamination levels and the decay rate of water vapor around the spacecraft were found to be in excellent agreement with prelaunch predictions. Future measurements include validation of the model of the aging spacecraft and investigation of the degradation of thermal radiators. C1 Johns Hopkins Univ, Appl Phys Lab, Tech Serv Dept, Laurel, MD 20723 USA. Phys Sci Inc, New England Business Ctr 20, Andover, MA 01810 USA. Sverdrup Technol Inc, Operat Grp, Arnold Engn Dev Ctr, Arnold AFB, TN 37389 USA. Aerospace Corp, Mat Grp, El Segundo, CA 90009 USA. Johns Hopkins Univ, Appl Phys Lab, Appl Res & Technol Dept, Laurel, MD 20723 USA. Johns Hopkins Univ, Appl Phys Lab, Dept Space, Laurel, MD 20723 USA. RP Uy, OM (reprint author), Johns Hopkins Univ, Appl Phys Lab, Tech Serv Dept, 11100 Johns Hopkins Rd, Laurel, MD 20723 USA. RI Erlandson, Robert/G-2767-2015 NR 24 TC 3 Z9 3 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD MAR-APR PY 1998 VL 35 IS 2 BP 170 EP 176 DI 10.2514/2.3325 PG 7 WC Engineering, Aerospace SC Engineering GA ZG315 UT WOS:000072989000008 ER PT J AU Green, BD Galica, GE Mulhall, PA Uy, OM Lesho, JC Boies, MT Benson, RC Phillips, TE Silver, DM Erlandson, RE Wood, BE Hall, DF Mill, JD AF Green, BD Galica, GE Mulhall, PA Uy, OM Lesho, JC Boies, MT Benson, RC Phillips, TE Silver, DM Erlandson, RE Wood, BE Hall, DF Mill, JD TI Local environment surrounding the Midcourse Space Experiment satellite during its first week SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article ID MSX; CONTAMINATION AB The environment measured surrounding the complex Midcourse Space Experiment spacecraft during its first week on orbit is reported. A suite of instruments including a pressure sensor, a neutral and an ion mass spectrometer, quartz crystal microbalances, and flashlamp-based water and particle detectors were activated within hours after launch. These instruments measured the gaseous composition, particulate, and film accretion temporal histories. Spacecraft environment cleanliness and response to operational activities were used to guide decisions about sensor operation. As a result of careful material selection and ground preparation procedures, the measured levels of condensible species were sufficiently low to permit Safe sensor operation after only a few days in orbit. C1 Phys Sci Inc, New England Med Ctr 20, Andover, MA 01810 USA. Johns Hopkins Univ, Appl Phys Lab, Technol Serv Dept, Laurel, MD 20723 USA. Sverdrup Technol Inc, Operat Grp, Arnold Engn Dev Ctr, Arnold AFB, TN 37389 USA. Aerospace Corp, Mat Grp, Los Angeles, CA 90009 USA. Environm Res Inst Michigan, MSX, Photon Res Associates, Arlington, VA 22209 USA. Johns Hopkins Univ, Appl Phys Lab, Space Dept, Laurel, MD 20723 USA. Johns Hopkins Univ, Appl Phys Lab, Appl Res & Technol Dept, Laurel, MD 20723 USA. RP Green, BD (reprint author), Phys Sci Inc, New England Med Ctr 20, 20 New England Business Ctr, Andover, MA 01810 USA. RI Erlandson, Robert/G-2767-2015 NR 16 TC 4 Z9 4 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD MAR-APR PY 1998 VL 35 IS 2 BP 183 EP 190 DI 10.2514/2.3308 PG 8 WC Engineering, Aerospace SC Engineering GA ZG315 UT WOS:000072989000010 ER PT J AU Cillessen, BJ AF Cillessen, BJ TI Embracing the bomb: Ethics, morality, and nuclear deterrence in the US Air Force, 1945-1955 SO JOURNAL OF STRATEGIC STUDIES LA English DT Review AB For many years the US Air Force was the only institution on the planet responsible for planning nuclear strikes and capable of delivering such a blow. This article addresses how leading early Cold War US Air Force officers viewed nuclear weapons in ethical terms and why they believed themselves to be traveling the road of higher morality. The work draws extensively from the manuscript collections and printed primary sources of Air Force generals to show why, in a moral sense, the Air Force planned, threatened, and trained to kill millions upon millions of human beings, many of them civilian, with nuclear strategic bombing. C1 USAF, Washington, DC USA. RP Cillessen, BJ (reprint author), Euro NATO Joint Jet Pilot Training, Sheppard AFB, TX USA. NR 135 TC 2 Z9 2 U1 0 U2 2 PU FRANK CASS CO LTD PI ESSEX PA NEWBURY HOUSE, 900 EASTERN AVE, NEWBURY PARK, ILFORD, ESSEX IG2 7HH, ENGLAND SN 0140-2390 J9 J STRATEGIC STUD JI J. Strateg. Stud. PD MAR PY 1998 VL 21 IS 1 BP 96 EP 134 DI 10.1080/01402399808437710 PG 39 WC International Relations; Political Science SC International Relations; Government & Law GA ZY816 UT WOS:000074663500006 ER PT J AU Troutman, WB Barstow, TJ Galindo, AJ Cooper, DM AF Troutman, WB Barstow, TJ Galindo, AJ Cooper, DM TI Abnormal dynamic cardiorespiratory responses to exercise in pediatric patients after Fontan procedure SO JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY LA English DT Article ID CONGENITAL HEART-DISEASE; OXYGEN-UPTAKE; TRICUSPID ATRESIA; CHILDREN; ADULTS; VENTILATION; PARAMETERS; RECOVERY; KINETICS; REPAIR AB Objectives. Novel protocols were used to focus on dynamic cardiorespiratory function during submaximal exercise and on the recovery from 1-min pulses of exercise in children who had undergone Fontan corrections for single-vent-ride lesions, Background. Particularly in children, maximal oxygen uptake ((V) over dotO(2)max), which is commonly used to assess the functional capability of patients after the Fontan procedure, is highly effort dependent and not physiologic and leads to uncomfortable metabolic and cardiorespiratory stress, Alternative approaches include the measurement of dynamic responses during progressive exercise and recovery after short. bursts of exercise, These strategies yield mechanistic insight into cardiorespiratory impairment and can be used to gauge limitations in daily life activity, Methods. Sixteen patients (mean [+/-SD] age 12.2 +/- 2.4 years; 9 boys) and 10 age-matched control subjects (mean age 12.2 +/- 2.4 years; 6 boys) performed two separate cycle ergometer tests in which gas exchange was measured on a breath by breath basis: 1) Progressive exercise was used to determine the dynamic relation among (V) over dotO(2), carbon dioxide production ((V) over dotCO(2)), ventilation ((V) over dotE), heart rate (HR) and work rate (WR). 2) A 1-min constant WR test was used to determine the recovery time for gas exchange and HR. Results. Peak (V) over dotO(2) and anaerobic threshold were reduced in patients who underwent the Fontan procedure compared with control subjects by 57% and 52%, respectively (p < 0.001), Dynamic relations during progressive exercise-Delta(V) over dotO(2)/Delta HR and Delta(V) over dot O-2/Delta WR-were decreased (p < 0.001) and Delta(V) over dotE/Delta over dotCO(2) , was increased (p < 0.005) in the Fontan group patients, Recovery times for HR and (V) over dotO(2) were prolonged in the Fontan group patients by 154% and 69%, respectively (p < 0.01), Conclusions. The results demonstrate that submaximal gas exchange responses to progressive exercise and recovery times after brief high intensity exercise are abnormal in patients after the Fontan procedure, These observations complement the findings of reduced (V) over dot(2)max observed here and by others, We speculate that the mechanisms for these responses are related to 1) a pervasive reduction in stroke volume for both low and high intensity exercise, 2) an abnormal linkage of ventilation to tissue carbon dioxide production, and 3) increased dependence on anaerobic metabolism in skeletal muscles, The prolonged recovery of HR and (V) over dotO(2), provides a possible mechanism for reduced physical activity. (C) 1998 by the American College of Cardiology. C1 Univ Calif Los Angeles, Sch Med, Dept Pediat, Div Pediat Cardiol, Westwood, CA USA. Harbor UCLA Med Ctr, Dept Pediat, Div Resp & Crit Care, Torrance, CA 90509 USA. RP Troutman, WB (reprint author), 81 MDOS-SGOC,301 Fisher St,Room 1A132, Keesler AFB, MS 39534 USA. FU NICHD NIH HHS [HD 269239] NR 27 TC 57 Z9 60 U1 0 U2 1 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 0735-1097 J9 J AM COLL CARDIOL JI J. Am. Coll. Cardiol. PD MAR 1 PY 1998 VL 31 IS 3 BP 668 EP 673 DI 10.1016/S0735-1097(97)00545-7 PG 6 WC Cardiac & Cardiovascular Systems SC Cardiovascular System & Cardiology GA YZ761 UT WOS:000072289000028 PM 9502651 ER PT J AU Brewer, CD Duncan, BD Barnard, KJ Watson, EA AF Brewer, CD Duncan, BD Barnard, KJ Watson, EA TI Coupling efficiencies for general-target-illumination ladar systems incorporating single-mode optical fiber receivers SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION LA English DT Article AB A rigorous method for modeling received power coupling efficiency (eta(F/R)) and transmitted power coupling efficiency (eta(F/T)) in a general-target-illumination ladar system is presented. For our analysis we concentrate on incorporating a single-mode optical fiber into the ladar return signal path. By developing expressions for both eta(F/R) and eta(F/T) for a simple, diffuse target, our model allows for varying range, beam size on target, target diameter, and coupling optics. Through numerical analysis eta(F/R) is shown to increase as the range to target increases and decrease as target diameter increases, and eta(F/T) is shown to decrease with target range. A baseline signal-to-noise ratio analysis of the system is also provided for varying illumination schemes. (C) 1998 Optical Society of America. C1 Univ Dayton, Ctr Electroopt, Dayton, OH 45469 USA. USAF, Wright Lab, EO Sensor Technol Branch, Wright Patterson AFB, OH 45433 USA. RP Duncan, BD (reprint author), Univ Dayton, Ctr Electroopt, 300 Coll Pk, Dayton, OH 45469 USA. NR 15 TC 0 Z9 0 U1 0 U2 1 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0740-3232 J9 J OPT SOC AM A JI J. Opt. Soc. Am. A-Opt. Image Sci. Vis. PD MAR PY 1998 VL 15 IS 3 BP 736 EP 747 DI 10.1364/JOSAA.15.000736 PG 12 WC Optics SC Optics GA YY732 UT WOS:000072178300021 ER PT J AU Sherriff, RE AF Sherriff, RE TI Analytic expressions for group-delay dispersion and cubic dispersion in arbitrary prism sequences SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID PULSES; LASER; PHASE AB A simple expression is obtained for the wavelength-dependent optical path length through a completely general N-prism sequence. Once the prisms' rotational orientations are fixed, a one-time calculation yields analytic expressions for the group-delay dispersion and cubic dispersion. The technique can be generalized for higher dispersion orders. As an example, expressions for Proctor-Wise prism sequences [Opt. Lett. 17, 1295 (1992)] constructed from a variety of glasses are produced. The analytic expressions for this sequence permit an exhaustive search of relative prism translations. The arrangement that produces the smallest cubic dispersion for a given group-delay dispersion and total optical path is found. (C) 1998 Optical Society of America.[S0740-3224(98)03203-2]. C1 USAF, Wright Lab, AADP, Avion Directorate, Wright Patterson AFB, OH 45433 USA. RP Sherriff, RE (reprint author), USAF, Wright Lab, AADP, Avion Directorate, Wright Patterson AFB, OH 45433 USA. NR 6 TC 25 Z9 25 U1 1 U2 3 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0740-3224 J9 J OPT SOC AM B JI J. Opt. Soc. Am. B-Opt. Phys. PD MAR PY 1998 VL 15 IS 3 BP 1224 EP 1230 DI 10.1364/JOSAB.15.001224 PG 7 WC Optics SC Optics GA ZA564 UT WOS:000072377200036 ER PT J AU Teichman, JMH Johnson, AJ Yates, JT Angle, BN Dirks, MS Muirhead, JT Thompson, IM Pearle, MS AF Teichman, JMH Johnson, AJ Yates, JT Angle, BN Dirks, MS Muirhead, JT Thompson, IM Pearle, MS TI Color vision deficits during laser lithotripsy using safety goggles for coumarin green or alexandrite but not with holimium : YAG laser safety goggles SO JOURNAL OF UROLOGY LA English DT Article DE lasers; lithotripsy; color perception; color vision defects; eye protective devices ID MUNSELL 100-HUE TEST; PERFORMANCE; WAVELENGTH AB Purpose: Laser lithotripsy requires urologists to wear laser eye protection. Laser eye protection devices screen out specific light wavelengths and may distort color perception. This study tests whether urologists risk color confusion when wearing laser eye protection devices for laser lithotripsy. Materials and Methods: Urologists were tested with the Farnsworth Dichotomous Test for Color Blindness (D-15) and the Farnsworth-Munsell 100-Hue Test (FM-100) without (control) and with laser eye protection devices for coumarin green, alexandrite and holmium:YAG lasers. Error scores were tabulated. The pattern of color deficits was characterized with confusion angles, confusion index (C-index), scatter index (S-index) and color axes. Laser eye protection devices were tested with spectrophotometry for spectral transmittance and optical density. Results: The D-15 transposition errors (mean plus or minus standard deviation) for control, holmium:YAG, alexandrite and coumarin green laser eye protection were 0 +/- 0, 0 +/- 0, 0.3 +/- 0.5 and 6.4 +/- 1.6, respectively (p = 0.0000001). The FM-100 error scores (mean plus or minus standard deviation) were 20 +/- 15, 20 +/- 14, 91 +/- 32 and 319 +/- 69, respectively (p = 0.0001). The confusion index scores indicated a mild color confusion for the alexandrite and pronounced color confusion for the coumarin green laser eye protection. The confusion angles and scatter indexes mimicked a congenital blue-yellow deficit for coumarin green laser eye protection. Color axes showed no significant deficits for control or holmium:YAG laser eye protection in any subject, red-green axis deficits in 3 of 6 tested with alexandrite and blue-yellow axis deficits in 12 of 12 tested with coumarin green (p < 0.001). Spectrophotometry showed that laser eye protection for coumarin green blocks light less than 550 nm., alexandrite blocks light greater than 650 nm. and holmium:YAG blocks light greater than 825 nm. Conclusions: Laser eye protection for coumarin green causes pronounced blue-yellow color confusion, whereas alexandrite causes mild red-green color confusion among urologists, holmium:YAG causes no significant color confusion compared to controls. The differences are explained by laser eye protection spectrophotometry characteristics and visual physiology. C1 Univ Texas, Hlth Sci Ctr, Div Urol, San Antonio, TX 78284 USA. Brooke Army Med Ctr, Dept Ophthalmol, Ft Sam Houston, TX 78234 USA. Brooke Army Med Ctr, Div Urol, Ft Sam Houston, TX 78234 USA. Armstrong Lab, Visual Electrodiagnost, Ophthalmol Branch, Brooks AFB, TX 78235 USA. Aeromed Consultat Serv, Brooks AFB, TX 78235 USA. Univ Texas, SW Med Ctr, Div Urol, Dallas, TX USA. RP Teichman, JMH (reprint author), Univ Texas, Hlth Sci Ctr, Div Urol, 7703 Floyd Curl Dr, San Antonio, TX 78284 USA. NR 20 TC 5 Z9 5 U1 1 U2 2 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 USA SN 0022-5347 J9 J UROLOGY JI J. Urol. PD MAR PY 1998 VL 159 IS 3 BP 683 EP 689 DI 10.1016/S0022-5347(01)63700-5 PG 7 WC Urology & Nephrology SC Urology & Nephrology GA YW252 UT WOS:000071913700011 PM 9474125 ER PT J AU Beheshti, MV Dolmatch, BL Jones, MP AF Beheshti, MV Dolmatch, BL Jones, MP TI Technical considerations in covering and deploying a wallstent endoprosthesis for the salvage of a failing transjugular intrahepatic portosystemic shunt SO JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY LA English DT Article DE shunts, portosystemic; stents and prostheses ID ASCITES; MANAGEMENT; OCCLUSION; SWINE; TIPS C1 USAF, Med Ctr, Dept Radiol, Wright Patterson AFB, OH 45433 USA. USAF, Med Ctr, Dept Med, Div Gastroenterol, Wright Patterson AFB, OH 45433 USA. Cleveland Clin Fdn, Dept Vasc & Intervent Radiol, Cleveland, OH 44195 USA. RP Beheshti, MV (reprint author), Radiol Consultants PC, 4 Grayan Ct, Little Rock, AK 72211 USA. NR 18 TC 8 Z9 8 U1 0 U2 1 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 USA SN 1051-0443 J9 J VASC INTERV RADIOL JI J. Vasc. Interv. Radiol. PD MAR-APR PY 1998 VL 9 IS 2 BP 289 EP 293 DI 10.1016/S1051-0443(98)70271-4 PG 5 WC Radiology, Nuclear Medicine & Medical Imaging; Peripheral Vascular Disease SC Radiology, Nuclear Medicine & Medical Imaging; Cardiovascular System & Cardiology GA ZC834 UT WOS:000072622800014 PM 9540913 ER PT J AU Parsons, DS Stivers, FE Giovanetto, DR Phillips, SE AF Parsons, DS Stivers, FE Giovanetto, DR Phillips, SE TI Type I posterior laryngeal clefts SO LARYNGOSCOPE LA English DT Article ID LARYNGOTRACHEOESOPHAGEAL CLEFTS; MANAGEMENT; DIAGNOSIS AB Posterior laryngeal clefts (PLCs) are described in the literature as rare laryngeal abnormalities. The authors believe type I clefts are much more common than previously reported. In two busy pediatric tertiary care centers, such clefts are the second most common congenital laryngeal finding at rigid endoscopy, second only to laryngomalacia. PLCs frequently present with symptomatology that can be attributed to other common disease processes and are often undiagnosed unless the surgeon maintains a high index of suspicion and specifically examines the posterior glottis by palpation during microlaryngoscopy. This report presents a series of 41 patients with type I PLCs, reviews their subtle and often confusing presenting signs and symptoms, and describes a simple yet reliable method of diagnosis. C1 Univ Missouri, Sch Med, Dept Surg, Columbia, MO 65211 USA. Univ Missouri, Sch Med, Dept Pediat, Columbia, MO 65211 USA. Univ Missouri, Sch Med, Dept Pediat Otolaryngol, Columbia, MO 65211 USA. Ear Nose & Throat Specialties, Lincoln, NE USA. Wilford Hall USAF Med Ctr, Lackland AFB, TX 78236 USA. RP Parsons, DS (reprint author), Div Otolaryngol, 1 Hosp Dr,MA314, Columbia, MO 65212 USA. NR 14 TC 43 Z9 45 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 USA SN 0023-852X J9 LARYNGOSCOPE JI Laryngoscope PD MAR PY 1998 VL 108 IS 3 BP 403 EP 410 DI 10.1097/00005537-199803000-00017 PG 8 WC Medicine, Research & Experimental; Otorhinolaryngology SC Research & Experimental Medicine; Otorhinolaryngology GA ZA684 UT WOS:000072390700017 PM 9504615 ER PT J AU Puffer, RL AF Puffer, RL TI What they didn't teach you about World War II SO LIBRARY JOURNAL LA English DT Book Review C1 USAF, Hist Prog, Victorville, CA USA. RP Puffer, RL (reprint author), USAF, Hist Prog, Victorville, CA USA. NR 1 TC 0 Z9 0 U1 1 U2 1 PU BOWKER MAGAZINE GROUP CAHNERS MAGAZINE DIVISION PI NEW YORK PA 249 W 17TH ST, NEW YORK, NY 10011 USA SN 0363-0277 J9 LIBR J JI Libr. J. PD MAR 1 PY 1998 VL 123 IS 4 BP 106 EP 106 PG 1 WC Information Science & Library Science SC Information Science & Library Science GA YZ612 UT WOS:000072271500115 ER PT J AU Talcott, GW Poston, WSC Haddock, CK AF Talcott, GW Poston, WSC Haddock, CK TI Co-occurrent use of cigarettes, alcohol, and caffeine in a retired military population SO MILITARY MEDICINE LA English DT Article ID SMOKING CESSATION; DRUG-USE; COFFEE; NICOTINE; TOBACCO; HEALTH; DISEASE; ADULTS AB Previous studies have linked the use of caffeine, nicotine, and alcohol to health complications and have also found that the use of these substances significantly covary, Given the prevalence of health problems of older adults, it is surprising that no studies to date have examined the co-occurrent use of alcohol, caffeine, and nicotine in a senior population. This investigation evaluated the co-occurrent use of cigarettes, caffeine, and alcohol in a community sample of older Americans. Respondents (1,095 women and 1,371 men) completed a questionnaire examining their use of caffeine, nicotine, and alcohol. This study replicated earlier findings that tobacco, caffeine, and alcohol use co-occur and that there are consistent use patterns for these substances, The results suggest that health organizations could better target services by prescreening for smoking, alcohol, and caffeine use and possibly targeting smokers and ex-smokers for potentially problematic use patterns of caffeine and alcohol. C1 Wilford Hall USAF Med Ctr, Lackland AFB, TX 78236 USA. RP Talcott, GW (reprint author), Wilford Hall USAF Med Ctr, 2200 Bergquist Dr,Suite 1, Lackland AFB, TX 78236 USA. NR 37 TC 16 Z9 16 U1 2 U2 3 PU ASSN MILITARY SURG US PI BETHESDA PA 9320 OLD GEORGETOWN RD, BETHESDA, MD 20814 USA SN 0026-4075 J9 MIL MED JI Milit. Med. PD MAR PY 1998 VL 163 IS 3 BP 133 EP 138 PG 6 WC Medicine, General & Internal SC General & Internal Medicine GA ZA537 UT WOS:000072374300002 PM 9542850 ER PT J AU Menkes, DL Hood, DC Ballesteros, RA Williams, DA AF Menkes, DL Hood, DC Ballesteros, RA Williams, DA TI Root stimulation improves the detection of acquired demyelinating polyneuropathies SO MUSCLE & NERVE LA English DT Article; Proceedings Paper CT 43rd Annual Meeting of the AAEM CY OCT 05, 1996 CL MINNEAPOLIS, MINNESOTA SP AAEM DE root stimulation; conduction block; demyelination; immunoglobulin; neuropathy ID GUILLAIN-BARRE-SYNDROME; INTRAVENOUS IMMUNOGLOBULIN TREATMENT; CERVICAL MAGNETIC STIMULATION; MULTIFOCAL MOTOR NEUROPATHY; PERIPHERAL-NERVE DISORDERS; PROXIMAL CONDUCTION BLOCK; IMMUNE GLOBULIN; NORTHERN CHINA; COIL STIMULATION; DOUBLE-BLIND AB Thirty-one patients with a presentation compatible with an acquired demyelinating polyradiculoneuropathy were prospectively evaluated for proximal conduction block using root stimulation (RS) of cervical and/or lumbar roots. These same techniques were applied to 78 controls (40 pathological). Proximal conduction block was noted in 20/31 cases and none of the controls. Only 7 of 31 cases met published demyelinating criteria. Intravenous immune globulin therapy was completed by 21/31 patients and 20/21 responded. RS is superior to published electrophysiologic criteria for identifying demyelinating polyneuropathies and predicting who will respond to treatment. RS should be performed in all patients suspected of having an acquired demyelinating polyneuropathy when traditional nerve conduction studies criteria are nondiagnostic. RS reliably predicts those likely to respond to immunosuppressive therapy. (C) 1998 John Wiley & Sons, Inc. C1 Univ Louisville, Dept Neurol, Louisville, KY 40292 USA. USAF, David Grant Med Ctr, Dept Med, Neurol Sect, Travis AFB, CA 94535 USA. RP Menkes, DL (reprint author), Univ Louisville, Dept Neurol, 500 S Preston St, Louisville, KY 40292 USA. NR 46 TC 43 Z9 43 U1 1 U2 1 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0148-639X J9 MUSCLE NERVE JI Muscle Nerve PD MAR PY 1998 VL 21 IS 3 BP 298 EP 308 DI 10.1002/(SICI)1097-4598(199803)21:3<298::AID-MUS3>3.0.CO;2-5 PG 11 WC Clinical Neurology; Neurosciences SC Neurosciences & Neurology GA YY281 UT WOS:000072131400003 PM 9486858 ER PT J AU Simpson, JR Montgomery, DC AF Simpson, JR Montgomery, DC TI A robust regression technique using compound estimation SO NAVAL RESEARCH LOGISTICS LA English DT Article ID BOUNDED-INFLUENCE; SQUARES AB Least squares fitting of regression models is a widely used technique. The presence of outliers in the data can have an adverse effect on the method of least squares, resulting in a model that does not adequately fit to the bulk of the data. For this situation, robust regression techniques have been proposed as an improvement to the method of least squares. We propose a robust regression procedure that performs well relative to the current robust methods against a variety of dataset types. Evaluations are performed using datasets without outliers (testing efficiency), with a large percentage of outliers (testing breakdown), and with high leverage outliers (testing bounded influence). The datasets are based on 2-level factorial designs that include axial points to evaluate leverage effects. A Monte Carlo simulation approach is used to evaluate the estimating capability of the proposed procedure relative to several competing methods. We also provide an application to estimating costs for government satellites. (C) 1998 John Wiley & Sons, Inc. C1 USAF Acad, Dept Math Sci, Colorado Springs, CO 80840 USA. Arizona State Univ, Dept Ind & Management Syst Engn, Tempe, AZ 85287 USA. RP Simpson, JR (reprint author), USAF Acad, Dept Math Sci, Colorado Springs, CO 80840 USA. NR 26 TC 7 Z9 7 U1 0 U2 0 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0894-069X EI 1520-6750 J9 NAV RES LOG JI Nav. Res. Logist. PD MAR PY 1998 VL 45 IS 2 BP 125 EP 139 DI 10.1002/(SICI)1520-6750(199803)45:2<125::AID-NAV1>3.0.CO;2-A PG 15 WC Operations Research & Management Science SC Operations Research & Management Science GA YX278 UT WOS:000072024200001 ER PT J AU Schulte, GA Hermesch, CB Vandewalle, KS Buikema, DJ AF Schulte, GA Hermesch, CB Vandewalle, KS Buikema, DJ TI Early fracture resistance of amalgapin-retained complex amalgam restorations SO OPERATIVE DENTISTRY LA English DT Article ID TRANSVERSE STRENGTH; PINS AB Amalgapins are susceptible to early fracture during matrix removal and carving. The purpose of this study was to examine the early fracture resistance of amalgapin-retained restorations using a spherical amalgam alloy, an admired amalgam alloy, a combination of admired alloy over the spherical alloy, and a recently introduced modified spherical amalgam alloy. Four amalgapin channels with a diameter of 1.4 mm and depth of 2 mm were prepared in cylinders of Macor, a machinable ceramic material. The amalgapins were hand condensed, and the bulk of the restoration was mechanically condensed. In the group using the combination of alloys, 800 mg of spherical alloy was condensed into the amalgapins and over the floor of the preparation. The admired alloy was then condensed over the spherical alloy to build up the bulk of the restoration. Using an Instron Universal Testing Machine, the restorations were tested to shear failure at an average of 15.8 +/- 1.3 minutes after the initiation of trituration of the amalgam alloy. A metal ring was placed around the restoration and pulled 90 degrees to the long axis to simulate matrix band removal. Data were analyzed using Kruskal-Wallis procedures. The fracture resistance of the spherical alloy group and the spherical/admired group were significantly higher than admired or Tytin FC. All fractures occurred in amalgam at the entrance to the amalgapin channel. The combination of spherical and admired amalgam alloys in a restoration may reduce the potential for early dislodgment while allowing additional time for carving. C1 Dunn Dent Clin, Dept Gen Dent, Lackland AFB, TX 78236 USA. RP Schulte, GA (reprint author), Dunn Dent Clin, Dept Gen Dent, 59th Med Wing,DSG 1615 Truemper St, Lackland AFB, TX 78236 USA. NR 26 TC 1 Z9 1 U1 0 U2 0 PU UNIV WASHINGTON PI SEATTLE PA SCHOOL DENTISTRY SM-57, SEATTLE, WA 98195 USA SN 0361-7734 J9 OPER DENT JI Oper. Dent. PD MAR-APR PY 1998 VL 23 IS 3 BP 108 EP 112 PG 5 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA ZK225 UT WOS:000073297900002 PM 9656920 ER PT J AU Holck, DEE Dutton, JJ Proia, A Khawly, J Mittra, R Dev, S Imami, N AF Holck, DEE Dutton, JJ Proia, A Khawly, J Mittra, R Dev, S Imami, N TI Rate of vascularization of coralline hydroxyapatite spherical implants pretreated with saline/gentamicin, rTGF-beta 2, and autogenous plasma SO OPHTHALMIC PLASTIC AND RECONSTRUCTIVE SURGERY LA English DT Article DE enucleation; hydroxyapatite; orbital implant; angiogenesis ID CHICK CHORIOALLANTOIC MEMBRANE; ORBITAL IMPLANTS; HISTOPATHOLOGIC CORRELATION; FIBROVASCULAR INGROWTH; POROUS HYDROXYAPATITE; ANGIOGENESIS FACTORS; OCULAR IMPLANT; FIBRIN; INVIVO; HYDROXYLAPATITE AB Several authors have reported significant exposure rates using the hydroxyapatite orbital implant in the treatment of the anophthalmic socket. Histologic studies by ourselves and others have suggested that lack of fibrovascular ingrowth into the implants may contribute to conjunctival breakdown and exposure. Recently, much attention has been given to angiogenic factors, such as rTGF-beta 2 and those found in plasma, in accelerating wound healing and fibrovascular ingrowth. This pilot study compares the rate of vascularization of hydroxyapatite orbital implants pretreated with plasma, rTGF-beta 2, and a saline/gentamicin solution with that in untreated controls in a population of New Zealand albino rabbits. Hydroxyapatite orbital spheres were implanted subcutaneously and in enucleated orbits. Untreated implants were used as a control. Implants pretreated with plasma, rTGF-beta 2, and a saline/gentamicin solution were removed and examined histologically at weekly intervals for the first 3 weeks after implantation. Histologic studies demonstrated that the rate of vascularization significantly increased between 2 and 3 weeks postoperatively in all study groups. Pretreating the implants with rTGF-beta 2 in phosphate buffered solution (PBS) or autogenous plasma did not significantly increase the rate of vascularization in comparison with controls at weeks 1 and 2. However, pretreating the implants with a saline/gentamicin solution or PBS alone was associated with an increased rate of vascularization at weeks 2 and 3. No statistically significant difference in vascularization was noted between the subcutaneous and orbital implants at any week. Hydroxyapatite implants pretreated with saline/gentamicin or phosphate buffered solutions underwent more rapid vascularization at weeks 2 and 3 in comparison with controls. Additionally, all groups were noted to have a more rapid rate of ingrowth between weeks 2 and 3 than between weeks 1 and 2. Plasma and rTGF-beta 2 (at the dose used) did not significantly alter the rate of vascularization of hydroxyapatite implants during the first 2 to 3 weeks. The significance of these findings is discussed. C1 Wilford Hall USAF Med Ctr, San Antonio, TX 78236 USA. RP Holck, DEE (reprint author), Dept Ophthalmol, PSSE, 2200 Bergquist Dr,Suite 1, San Antonio, TX 78236 USA. NR 39 TC 18 Z9 19 U1 0 U2 1 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 USA SN 0740-9303 J9 OPHTHALMIC PLAST REC JI Ophthalmic Plast. Reconstr. Surg. PD MAR PY 1998 VL 14 IS 2 BP 73 EP 80 DI 10.1097/00002341-199803000-00001 PG 8 WC Ophthalmology; Surgery SC Ophthalmology; Surgery GA ZD604 UT WOS:000072703200001 PM 9558662 ER PT J AU Reed, JB Scales, DK Wong, MT Lattuada, CP Dolan, MJ Schwab, IR AF Reed, JB Scales, DK Wong, MT Lattuada, CP Dolan, MJ Schwab, IR TI Bartonella henselae neuroretinitis in cat scratch disease - Diagnosis, management, and sequelae SO OPHTHALMOLOGY LA English DT Article; Proceedings Paper CT 94th Annual Meeting of the American-Society-for-Microbiology CY MAY 23-27, 1994 CL LAS VEGAS, NEVADA SP Amer Soc Microbiol ID ROCHALIMAEA-HENSELAE; BACILLARY ANGIOMATOSIS; INFECTIONS; ANTIGENS; VISION; GIRL AB Objective: This study aimed to report the long-term outcomes of patients treated with an antibiotic drug combination for Bartonella henselae neuroretinitis. Design: The study design was a retrospective case series. Participants: Seven consecutive patients with neuroretinitis and cat scratch disease participated. Interventions: Patients underwent medical and ophthalmic evaluations. Blood cultures were obtained, and B. henselae antibody titers were measured. Tuberculosis, Lyme, toxoplasmosis, syphilis, and sarcoidosis were excluded. Patients received oral doxycycline 100 mg and rifampin 300 mg twice daily for 4 to 6 weeks and were observed for an average of 16 months (range, 10-24 months), Formal electrophysiologic testing was performed in three patients after resolution of neuroretinitis. Main Outcome Measures: The changes in ocular inflammation and visual function associated with treatment were recorded. Follow-up examinations and electrophysiologic testing documented sequelae. Results: Patients presented following cat exposure with fever, malaise, and blurred vision. Decreased visual acuity (ranging from 20/40 to counting fingers) frequently was associated with dyschromatopsia and afferent pupillary defects. Ophthalmoscopic analysis showed signs of neuroretinitis, including nerve fiber layer hemorrhages, cotton-wool spots, multiple discrete lesions in the deep retina, and stellate macular exudates. B. henselae infection was confirmed with positive blood cultures or elevated immunofluorescent antibody titers or both. Therapy appeared to promote resolution of neuroretinitis, restoration of visual acuity, and clearance of bacteremia. After 1 to 2 years, two eyes had residual disc parlor, afferent pupillary defects, retinal pigmentary changes, and mildly decreased visual acuity. Electrophysiologic studies showed that when compared to the fellow eye, affected eyes had subnormal contrast sensitivity, abnormal color vision, and abnormal visually evoked potentials. Conversely, electroretinograms were normal in all subjects. Conclusions: B. henselae is a cause of neuroretinitis in cat scratch disease. Compared to historic cases, doxycycline and rifampin appeared to shorten the course of disease and hasten visual recovery. Long-term prognosis is good, but some individuals may acquire a mild postinfectious optic neuropathy. C1 Univ Calif Davis, Dept Ophthalmol, Sacramento, CA 95816 USA. Wilford Hall USAF Med Ctr, Dept Ophthalmol, Lackland AFB, TX 78236 USA. Wilford Hall USAF Med Ctr, Dept Infect Dis, Lackland AFB, TX 78236 USA. RP Schwab, IR (reprint author), Univ Calif Davis, Dept Ophthalmol, 1603 Alhambra Blvd, Sacramento, CA 95816 USA. NR 34 TC 129 Z9 136 U1 0 U2 2 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 USA SN 0161-6420 J9 OPHTHALMOLOGY JI Ophthalmology PD MAR PY 1998 VL 105 IS 3 BP 459 EP 466 DI 10.1016/S0161-6420(98)93028-7 PG 8 WC Ophthalmology SC Ophthalmology GA YZ385 UT WOS:000072249100030 PM 9499776 ER PT J AU Peterson, P Sharma, MP AF Peterson, P Sharma, MP TI Modelling of threshold and extraction efficiency in Pr3+ ZBLAN upconversion fibre lasers using two-photon pumping SO OPTICAL AND QUANTUM ELECTRONICS LA English DT Article ID DOPED FIBER AMPLIFIERS; UP-CONVERSION LASER; SOLID-STATE; YAG LASERS; BLUE; PERFORMANCE; TM AB We model the steady-state threshold and extracted power of a two-photon incoherently pumped upconversion fibre laser. Our threshold analysis is entirely analytic, and along with this derivation we obtain an analytic threshold cutback formula. This takes a particularly simple form when the ground state pump absorption follows exponential absorption. We also numerically simulate the extracted laser power. The experiment which we simulate is upconversion in Pr3+ doped ZBLAN fibre lasing at 491 nm and pumped with 1017 nm and 835 nm diode lasers. Our formulas and simulations are mutually consistent and agree with the experiment to within 10%. C1 USAF, Phillips Lab, Nonlinear Opt Ctr Technol, LIDN, Kirtland AFB, NM 87117 USA. RP Peterson, P (reprint author), USAF, Phillips Lab, Nonlinear Opt Ctr Technol, LIDN, 3550 Aberdeen Ave SE, Kirtland AFB, NM 87117 USA. NR 15 TC 3 Z9 3 U1 1 U2 2 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0306-8919 J9 OPT QUANT ELECTRON JI Opt. Quantum Electron. PD MAR PY 1998 VL 30 IS 3 BP 161 EP 173 DI 10.1023/A:1006954027120 PG 13 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA ZY605 UT WOS:000074640400002 ER PT J AU Hasselbeck, MP Said, AA van Stryland, EW Sheik-Bahae, M AF Hasselbeck, MP Said, AA van Stryland, EW Sheik-Bahae, M TI Three-photon absorption in InAs SO OPTICAL AND QUANTUM ELECTRONICS LA English DT Article ID PICOSECOND INFRARED-SPECTROSCOPY; HOT HOLES; SEMICONDUCTORS; PULSES; INSB AB Using 125 ps laser pulses, we observe three-photon absorption in room temperature InAs at a wavelength of 9.54 mu m. This effect is readily identified by temperature-tuning the semiconductor bandgap through the three-photon absorption edge. A three-photon absorption coefficient of K-3 = 1 +/- 0.6 x 10(-3) cm(3) MW-2 is extracted from non-linear absorption data obtained with an open-aperture Z-scan. Time-resolved measurement at high irradiance reveals an increase of absorption due to hot carriers. We also present an autocorrelation measurement of our CO2 laser pulse that shows two complete optical free-induction-decay cycles. C1 USAF, Phillips Lab, Kirtland AFB, NM 87117 USA. Univ Cent Florida, Creol, Orlando, FL 32816 USA. Univ New Mexico, Dept Phys & Astron, Albuquerque, NM 87131 USA. RP Hasselbeck, MP (reprint author), Max Born Inst Nonlinear Opt & Ultrafast Spect, D-12489 Berlin, Germany. NR 18 TC 0 Z9 0 U1 1 U2 2 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0306-8919 J9 OPT QUANT ELECTRON JI Opt. Quantum Electron. PD MAR PY 1998 VL 30 IS 3 BP 193 EP 200 DI 10.1023/A:1006962228937 PG 8 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA ZY605 UT WOS:000074640400006 ER PT J AU Hardie, RC Vaidyanathan, M McManamon, F AF Hardie, RC Vaidyanathan, M McManamon, F TI Spectral band selection and classifier design for a multispectral imaging laser radar SO OPTICAL ENGINEERING LA English DT Article DE active; multispectral; imaging laser radar; spectral band selection AB A statistical spectral band selection procedure and classifiers for an active multispectral laser radar (LADAR) sensor are described. The sensor will operate in the 1 to 5 mu m wavelength region. The algorithms proposed are tested using library reflectance spectra for some representative background materials. The material classes considered include both natural (vegetation and soil) and man-made (camouflage cloth and tar-asphalt). The analysis includes noise statistics due to Gaussian receiver noise and target induced speckle variations in the LADAR return signal intensity. The results of this analysis are then directly applied to an artificially generated spatial template of a scene consisting of these four material classes. The performance of four different classifier algorithms, which include a minimum distance classifier, a log-domain minimum distance classifier, a Bayes speckle-only classifier, and a Bayes speckle-Gaussian classifier, are evaluated. We show that the Bayesian classifier designed for speckle and Gaussian noise statistics outperforms the other classifiers. Our results also indicate that even when exact knowledge of the observation model is available, the classifier performance for speckled images can be poor unless the number of integrated speckle cells is large. (C) 1998 Society of Photo-Optical Instrumentation Engineers. [S0091-3286(98)00403-6]. C1 Univ Dayton, Dept Elect & Comp Engn, Dayton, OH 45469 USA. USAF, Wright Lab, Electroopt Sensor Technol Branch, WL AAJT, Wright Patterson AFB, OH 45433 USA. RP Hardie, RC (reprint author), Univ Dayton, Dept Elect & Comp Engn, 300 Coll Pk Ave, Dayton, OH 45469 USA. NR 17 TC 11 Z9 12 U1 1 U2 4 PU SPIE - INTERNATIONAL SOCIETY FOR OPTICAL ENGINEERING PI BELLINGHAM PA POB 10, BELLINGHAM, WA 98227-0010 USA SN 0091-3286 J9 OPT ENG JI Opt. Eng. PD MAR PY 1998 VL 37 IS 3 BP 752 EP 762 DI 10.1117/1.601907 PG 11 WC Optics SC Optics GA ZC007 UT WOS:000072530200005 ER PT J AU Du, X Ahalt, SC Stribling, BE AF Du, X Ahalt, SC Stribling, BE TI Three-dimensional vector estimation for subcomponents of space object imagery SO OPTICAL ENGINEERING LA English DT Article DE space object identification; orientation vector estimation; image analysis; pose estimation; satellite images ID RECOGNITION AB We describe a model-based image analysis system that automatically estimates the 3-D orientation vectors of satellites and their subcomponents by analyzing images obtained from a ground-based optical surveillance system. We adopt a two-step approach: pose estimates are derived from comparisons with a model database and pose refinements are derived from photogrammetric information. The model database is formed by representing each available training image by a set of derived geometric primitives. To obtain fast access to the model database and to increase the probability of early successful matching, a novel index-hashing method is introduced. An affine point-matching method is also introduced for improving system performance on a wide variety of satellite shapes. We present recent results, which include our efforts at isolating and estimating orientation vectors from degraded imagery on a significant database of satellites. (C) 1998 Society of Photo-Optical Instrumentation Engineers. [S0091-3286(98)00603-5]. C1 Ohio State Univ, Dept Elect Engn, Columbus, OH 43210 USA. USAF, Opt Sect, Maui, HI 96753 USA. RP Du, X (reprint author), Ohio State Univ, Dept Elect Engn, 2015 Neil Ave, Columbus, OH 43210 USA. NR 13 TC 7 Z9 7 U1 0 U2 0 PU SPIE - INTERNATIONAL SOCIETY FOR OPTICAL ENGINEERING PI BELLINGHAM PA POB 10, BELLINGHAM, WA 98227-0010 USA SN 0091-3286 J9 OPT ENG JI Opt. Eng. PD MAR PY 1998 VL 37 IS 3 BP 798 EP 807 DI 10.1117/1.601912 PG 10 WC Optics SC Optics GA ZC007 UT WOS:000072530200010 ER PT J AU Kane, JS Kincaid, TG Hemmer, P AF Kane, JS Kincaid, TG Hemmer, P TI Optical processing with feedback using smart-pixel spatial light modulators SO OPTICAL ENGINEERING LA English DT Article DE spatial light modulators; optical feedback; signal processing; free space; ferroelectric AB A spatial light modulator is often used as the basic element in real-time recognition architectures. However, many of the devices suffer from poor uniformity and/or nonlinearities that affect the overall performance of any real-time recognition scheme. We propose using optical feedback as a method of improving device performance. We demonstrate both positive and negative feedback separately through a mixture of on-board electronic processors and optical polarization intensity encoding. Placing the spatial light modulator in a positive feedback system causes the system to act like a memory. Placing the spatial light modulator in a negative feedback system makes the spatial light modulator response more analog, which in turn leads to improved uniformity. (C) 1998 Society of Photo-Optical instrumentation Engineers. [S0091-3286(98)02103-5]. C1 Comp Opt Inc, Hudson, NH 03051 USA. Boston Univ, Boston, MA 02215 USA. USAF, Rome Lab, RL EROP, Hanscom AFB, MA 01731 USA. RP Kane, JS (reprint author), Comp Opt Inc, 120 Derry Rd, Hudson, NH 03051 USA. NR 10 TC 3 Z9 3 U1 0 U2 0 PU SPIE - INTERNATIONAL SOCIETY FOR OPTICAL ENGINEERING PI BELLINGHAM PA POB 10, BELLINGHAM, WA 98227-0010 USA SN 0091-3286 J9 OPT ENG JI Opt. Eng. PD MAR PY 1998 VL 37 IS 3 BP 942 EP 947 DI 10.1117/1.601646 PG 6 WC Optics SC Optics GA ZC007 UT WOS:000072530200027 ER PT J AU Wick, DV Gruneisen, MT Peterson, PR AF Wick, DV Gruneisen, MT Peterson, PR TI Phase-preserving wavefront amplification at 590 nm by stimulated Raman scattering SO OPTICS COMMUNICATIONS LA English DT Article DE stimulated Raman scattering; sodium wavefront amplification; phase ID MESOSPHERIC SODIUM; LASER AB This paper presents an experimental demonstration of high-gain optical-wavefront amplification by stimulated Raman scattering near the D-1 resonance in atomic sodium vapor. Single-pass weak-field gain of nearly 400 is achieved with only 800 mW of pump power. Through judicious focusing, the weak wavefront is confined to the central region of the focused pump wave where saturation of the dispersion profile minimizes phase distortions due to self-focusing effects. Phase-preserving amplification is demonstrated by interferometric measurements of an amplified TEM00 wavefront. (C) 1998 Elsevier Science B.V. C1 USAF, Phillips Lab, LIMS, Kirtland AFB, NM 87117 USA. RP Gruneisen, MT (reprint author), USAF, Phillips Lab, LIMS, 3550 Aberdeen Ave SE, Kirtland AFB, NM 87117 USA. EM gruneism@plk.af.mil NR 10 TC 1 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0030-4018 J9 OPT COMMUN JI Opt. Commun. PD MAR 1 PY 1998 VL 148 IS 1-3 BP 113 EP 116 DI 10.1016/S0030-4018(97)00606-8 PG 4 WC Optics SC Optics GA ZM718 UT WOS:000073568900024 ER PT J AU Schelonka, RL Raaphorst, FM Infante, D Kraig, E Teale, JM Infante, AJ AF Schelonka, RL Raaphorst, FM Infante, D Kraig, E Teale, JM Infante, AJ TI T cell receptor repertoire diversity and clonal expansion in human neonates SO PEDIATRIC RESEARCH LA English DT Article ID VARIABLE REGION GENES; POLYMERASE CHAIN-REACTION; HUMAN-ANTIBODY REPERTOIRE; BETA-CHAIN; ANTIGEN RECEPTOR; HUMAN FETAL; N-REGIONS; DEVELOPMENTAL REGULATION; IMMUNE-RESPONSES; SEGMENT USAGE AB Newborn human infants, particularly those born prematurely, are susceptible to infection with a variety of microorganisms. We questioned whether limitations in the T cell repertoire contribute to the neonatal immunocompromised state. To describe developmental changes of the T cell repertoire, cDNA segments corresponding to third complementarity regions (CDR3) of human umbilical cord blood T cell receptors (TCR) from 24-41-wk gestational age were amplified with TCR family-specific probes. The resulting amplified CDRs were visualized by fingerprinting and single strand conformation polymorphism (SSCP) analysis. At 24-wk gestation there were no limitations in TCRBV family usage, and the degree of CDR3 size heterogeneity was not different from the adult, However, earlier in gestation, CDR3s were shorter for all families and gradually increased in size until term, The extent of oligoclonal expansion observed in cord blood was greater than in adult peripheral blood (p = 0.03). T cell oligoclonal expansion was greatest at 29-33-wk gestation and declined toward term. Expansions were detectable in both CD4(+) and CD8(+) subpopulations. Our findings indicate that the genetic mechanisms of repertoire diversification appear intact as early as 24 wk of gestation, but repertoire diversity is limited as a result of smaller CDR3 sizes. In addition, there was a developmentally regulated progression of oligoclonally expanded T cells. These differences in the TCRBV repertoire add to the body of evidence demonstrating immaturity of the neonatal immune system. However, the role that these subtle differences are likely to play in the relative immunodeficiency of the neonate remains to be determined. C1 Univ Texas, Hlth Sci Ctr, Dept Pediat, Div Hematol Oncol & Immunol, San Antonio, TX 78284 USA. Univ Texas, Hlth Sci Ctr, Dept Microbiol, San Antonio, TX 78284 USA. Univ Texas, Hlth Sci Ctr, Dept Cellular & Struct Biol, San Antonio, TX 78284 USA. Wilford Hall USAF Med Ctr, Dept Pediat, Lackland AFB, TX 78236 USA. RP Infante, AJ (reprint author), Univ Texas, Hlth Sci Ctr, Dept Pediat, Div Hematol Oncol & Immunol, 7703 Floyd Curl Dr, San Antonio, TX 78284 USA. FU NIAID NIH HHS [AI33195, AI 19896] NR 61 TC 38 Z9 40 U1 0 U2 0 PU INT PEDIATRIC RESEARCH FOUNDATION, INC PI BALTIMORE PA 351 WEST CAMDEN ST, BALTIMORE, MD 21201-2436 USA SN 0031-3998 J9 PEDIATR RES JI Pediatr. Res. PD MAR PY 1998 VL 43 IS 3 BP 396 EP 402 DI 10.1203/00006450-199803000-00015 PG 7 WC Pediatrics SC Pediatrics GA YY363 UT WOS:000072139600015 PM 9505280 ER PT J AU Rentsch, JR Steel, RP AF Rentsch, JR Steel, RP TI Testing the durability of job characteristics as predictors of absenteeism over a six-year period SO PERSONNEL PSYCHOLOGY LA English DT Article ID CHARACTERISTICS MODEL; META-ANALYSIS; METHODOLOGICAL ISSUES; DIAGNOSTIC SURVEY; PSYCHOMETRIC PROPERTIES; ABSENCE MEASURES; NEED STRENGTH; WORK; SATISFACTION; ATTITUDES AB The purpose of this study was to test the relationships between job characteristics and absence over a 6-year period. Civilian employees from a large military organization participated. The results indicated that job characteristics continued to correlate significantly with a measure of absence frequency up to 6 years after the job characteristics had been assessed. The job characteristics measures also correlated significantly with a measure of time-lost absenteeism. Regression analyses revealed that job characteristics predicted absence frequency significantly over a 6-year period and time-lost absence for up to 4 years after job characteristics were assessed. The magnitudes of these relationships remained fairly constant across time. Results from regression analyses controlling for demographic variables indicated that job characteristics predicted time-lost and absence frequency for most years. Competence and need for achievement failed to moderate the job characteristics-absence relationships. C1 Wright State Univ, Dept Psychol, Dayton, OH 45435 USA. USAF, Inst Technol, Washington, DC 20330 USA. RP Rentsch, JR (reprint author), Wright State Univ, Dept Psychol, Dayton, OH 45435 USA. NR 49 TC 33 Z9 33 U1 3 U2 10 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0031-5826 J9 PERS PSYCHOL JI Pers. Psychol. PD SPR PY 1998 VL 51 IS 1 BP 165 EP 190 DI 10.1111/j.1744-6570.1998.tb00720.x PG 26 WC Psychology, Applied; Management SC Psychology; Business & Economics GA ZC831 UT WOS:000072622500008 ER PT J AU Ree, MJ AF Ree, MJ TI Visual revelations: Graphic tales of fate and deception from Napoleon Bonaparte to Ross Perot. SO PERSONNEL PSYCHOLOGY LA English DT Book Review C1 USAF, Res Lab, Brooks AFB, TX 78235 USA. RP Ree, MJ (reprint author), USAF, Res Lab, Brooks AFB, TX 78235 USA. NR 3 TC 1 Z9 1 U1 0 U2 1 PU PERSONNEL PSYCHOLOGY INC PI BOWLING GREEN PA 745 HASKINS ROAD, SUITE A, BOWLING GREEN, OH 43402 USA SN 0031-5826 J9 PERS PSYCHOL JI Pers. Psychol. PD SPR PY 1998 VL 51 IS 1 BP 226 EP 229 PG 4 WC Psychology, Applied; Management SC Psychology; Business & Economics GA ZC831 UT WOS:000072622500014 ER PT J AU Mickley, GA Cobb, BL AF Mickley, GA Cobb, BL TI Thermal tolerance reduces hyperthermia-induced disruption of working memory: A role for endogenous opiates? SO PHYSIOLOGY & BEHAVIOR LA English DT Article; Proceedings Paper CT 16th Annual Bioelectromagnetics-Society Meeting CY 1994 CL COPENHAGEN, DENMARK SP Bioelectromagnet Soc DE amnesia; thermal tolerance; working memory; microwave-induced hyperthermia; radiofrequency radiation; object recognition; rectal temperature; brain temperature ID LEVEL MICROWAVE IRRADIATION; ANTEROGRADE AMNESIA; BODY-TEMPERATURE; RATS; MAZE; DEPENDENCE; NALTREXONE; MORPHINE; INTERVAL; OPIOIDS AB Previous reports indicate that microwave-induced hyperthermia can impair learning and memory. Here, we report that preexposure to a single 20-min period of hyperthermia can produce thermal tolerance and, thereby, attenuate future physiological and behavioral reactions to heating. Because endogenous opioids have been implicated in thermoregulation and reactions to microwave exposure, we also determined how opioid receptor antagonism might modulate these effects. In an initial experiment, rats were exposed daily, over 5 successive days, to 600-MHz microwaves (at a whole-body specific absorption rate of 9.3 W/kg) or sham exposed. In animals exposed to microwaves, thermal tolerance was evidenced by declining rectal temperatures over time. Temperature reductions following microwave exposure were prominent after a single previous exposure. Therefore, in a second study, a single hyperthermic episode was used to induce thermal tolerance. On Day 1, rats were either exposed, over a 20-min period, to 600-MHz microwaves (at a whole-body specific absorption rate of 9.3 W/kg) or sham exposed. Just prior to radiation/sham-radiation treatment, rats received either saline or naltrexone (0.1 or 10 mg/kg, intraperitoneally (i.p.)). The following day (Day 2), rats were either microwave or sham exposed and tested on a task which measures the relative time subjects explore a familiar versus a novel stimulus object. Normothermic rats spend significantly more time in contact with new environmental components and less time with familiar objects. Brain (dura) and rectal temperatures were recorded on both days of the study. Microwave exposure produced a reliable hyperthermia which was significantly lower (on Day 2) in rats receiving repeated treatments (tolerant group). On the behavioral test, rats exposed only once to microwave-induced hyperthermia (nontolerant group) exhibited significantly different patterns of object discrimination than did tolerant or sham-exposed animals. Sham-exposed and tolerant animals showed a distinct preference for the new object whereas the nontolerant animals did not. Naltrexone (10 mg/kg) antagonized the hyperthermia-induced disruption of the object discrimination task; (in nontolerant rats) and produced patterns of object exploration that were similar to those of sham-irradiated and thermal-tolerant rats, suggesting that endogenous opioids play a role in the organism's response to heating. Taken together, these data are consistent with the conclusions that 1) microwave-induced hyperthermia can cause a dose-dependent disruption of the normal discrimination between new and familiar objects, 2) physiological reactions to a single hyperthermic episode can produce a thermotolerance that expresses itself in both reduced levels of hyperthermia and attenuated behavioral disruptions following microwave exposure, and 3) opioid antagonism can partially reverse some of the behavioral effects of microwave-induced hyperthermia. (C) 1998 Elsevier Science Inc. C1 Armstrong Lab, Radiofrequency Radiat Div, OER, Brooks AFB, TX 78235 USA. RP Mickley, GA (reprint author), Baldwin Wallace Coll, Dept Psychol, 275 Eastland Rd, Berea, OH 44017 USA. EM amickley@bw.ed NR 62 TC 8 Z9 8 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0031-9384 J9 PHYSIOL BEHAV JI Physiol. Behav. PD MAR PY 1998 VL 63 IS 5 BP 855 EP 865 DI 10.1016/S0031-9384(98)00010-9 PG 11 WC Psychology, Biological; Behavioral Sciences SC Psychology; Behavioral Sciences GA ZN303 UT WOS:000073632400017 PM 9618009 ER PT J AU Bostwick, JM Masterson, BJ AF Bostwick, JM Masterson, BJ TI Psychopharmacological treatment of delirium to restore mental capacity SO PSYCHOSOMATICS LA English DT Article ID INCOMPETENT PATIENTS; DECISION-MAKING; DEPRESSION; FLUMAZENIL; PROXY AB The authors report four patient cases of delirium in which medications were used to restore mental capacity when life-or-death treatment decisions were required. Although extensive literature on substituted judgment exists for delirium and depression compromising capacity to make competent decisions, the authors could locate to articles proposing aggressive delirium treatment for restoring patients' capacity to participate in their own care. Without surgical intervention, all four of the authors' patients faced imminent death. Without psychopharmacologic banishment of the patients' deliria, proxies would have been asked whether the patients should undergo potentially lifesaving but high-risk procedures. The patients would have lost the opportunity to express their wishes about heroic lifesaving medical measures. C1 Wilford Hall USAF Med Ctr MMPD, Dept Psychiat, Lackland AFB, TX 78236 USA. Wilford Hall USAF Med Ctr, Dept Internal Med, Lackland AFB, TX 78236 USA. RP Bostwick, JM (reprint author), Wilford Hall USAF Med Ctr MMPD, Dept Psychiat, 2200 Bergquist Dr,Ste 1, Lackland AFB, TX 78236 USA. NR 13 TC 10 Z9 10 U1 0 U2 0 PU AMER PSYCHIATRIC ASSOCIATION PI WASHINGTON PA 1400 K ST NW, WASHINGTON, DC 20005 USA SN 0033-3182 J9 PSYCHOSOMATICS JI Psychosomatics PD MAR-APR PY 1998 VL 39 IS 2 BP 112 EP 117 PG 6 WC Psychiatry; Psychology SC Psychiatry; Psychology GA ZJ929 UT WOS:000073267900004 PM 9584536 ER PT J AU Holck, DEE Dutton, JJ Pendergast, SD Klintworth, GK AF Holck, DEE Dutton, JJ Pendergast, SD Klintworth, GK TI Double choroidal malignant melanoma in an eye with apparent clinical regression SO SURVEY OF OPHTHALMOLOGY LA English DT Review DE choroidal malignant melanoma; enucleation; melanoma regression; multicentric choroidal melanomas; tumor ID NONCONTIGUOUS LOCAL RECURRENCE; PLAQUE THERAPY; UVEAL MELANOMA AB Multicentric melanomas in the same eye are rare, with few cases substantiated by histology and serial sectioning. We report a patient with two documented choroidal malignant melanomas in one eye. The initial turner spontaneously decreased in size for over 2 years before a second tumor appeared in a noncontiguous location in the same eye. After enucleation, serial sections showed that the two lesions were independent choroidal melanomas. We review the literature regarding multiple, independent intraocular choroidal malignant melanomas. (C) 1998 by Elsevier Science Inc. All rights reserved.). C1 Wilford Hall USAF Med Ctr, Dept Ophthalmol, PSSE, San Antonio, TX 78236 USA. Duke Univ, Ctr Eye, Durham, NC USA. RP Holck, DEE (reprint author), Wilford Hall USAF Med Ctr, Dept Ophthalmol, PSSE, 2200 Bergquist Dr, San Antonio, TX 78236 USA. NR 46 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 0039-6257 J9 SURV OPHTHALMOL JI Surv. Ophthalmol. PD MAR-APR PY 1998 VL 42 IS 5 BP 441 EP 448 DI 10.1016/S0039-6257(97)00136-7 PG 8 WC Ophthalmology SC Ophthalmology GA ZD464 UT WOS:000072688600003 PM 9548572 ER PT J AU Cloud, DJ Rainey, L AF Cloud, DJ Rainey, L TI Applied modeling and simulation: A new reference text with a systems engineering approach to M & S development SO TRANSACTIONS OF THE SOCIETY FOR COMPUTER SIMULATION INTERNATIONAL LA English DT Article DE text; reference; system development; system engineering; mission development AB This paper describes a new reference text entitled Applied Modeling and Simulation: An Integrated Approach to Development and Operation. This text is a first-ever, broad-based reference designed to provide a framework to define, develop, use and maintain cost-effective models and simulation in support of all phases of system development and operation. It provides a common starting point for building and communicating an explicit modeling and simulation (M&S) development process, using M&S to enhance the system acquisition process and provide insights for improved operations, establishing a baseline for continuous product improvement, and ultimately saving money in an era of reduced budgets. C1 USAF Acad, Dept Astronaut, Colorado Springs, CO 80840 USA. Aerospace Corp, Colorado Springs, CO USA. RP Cloud, DJ (reprint author), USAF Acad, Dept Astronaut, Colorado Springs, CO 80840 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU SOC COMPUTER SIMULATION PI SAN DIEGO PA PO BOX 17900, SAN DIEGO, CA 92177 USA SN 0740-6797 J9 T SOC COMPUT SIMUL I JI Trans. Soc. Comput. Simul. PD MAR PY 1998 VL 15 IS 1 BP 34 EP 38 PG 5 WC Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering SC Computer Science GA ZW391 UT WOS:000074406300005 ER PT J AU Cutler, JN Sanders, JH John, G AF Cutler, J. N. Sanders, J. H. John, G. TI X-ray absorption near edge structure (XANES) and conversion electron Mossbauer spectroscopy (CEMS) study of perfluoropolyalkylether based additives SO TRIBOLOGY LETTERS LA English DT Article DE XANES; Mossbauer; PFPAE additives; oxidation-corrosion AB This study provides critical insight regarding the interactions of perfluoropolyalkylether (PFPAE) additives with Fe-based alloys. PFPAEs are primary candidates for the development of high temperature liquid lubricants for the next generation of turbine engines because of their chemical and thermal stability. However, a PFPAE must be tailored for its particular application by the addition of soluble additives. Currently, two additives that show promise for improved performance are a substituted triphenyl phosphine and a bis-substituted benzothiazole. To date, little work has been reported on the mechanism by which these additives actually improve overall performance. In order to gain some under standing of how these additives work, a series of oxidation-corrosion tests were performed using these additives in Demnum with the resulting coupons examined by X-ray absorption near edge structure (XANES) and conversion electron Mossbauer spectroscopy (CEMS). C1 [Cutler, J. N.; Sanders, J. H.] Mat Directorate, WL MLBT, Wright Patterson AFB, OH 45433 USA. [John, G.] USAF, Dept Engn Phys, AFIT ENP, Inst Technol, Wright Patterson AFB, OH 45433 USA. RP Cutler, JN (reprint author), Mat Directorate, WL MLBT, Wright Patterson AFB, OH 45433 USA. FU Materials Directorate of Wright Laboratory; Wright Patterson Air Force Base; OH and the Air Force Office of Scientific Research; Bolling Air Force Base, DC; National Science Foundation (NSF) [DMR-95-31009] FX This work was supported by the Materials Directorate of Wright Laboratory, Wright Patterson Air Force Base, OH and the Air Force Office of Scientific Research, Bolling Air Force Base, DC. The authors are grateful to Drs. J.S. Zabinski and H.L. Paige for their thought provoking comments. We are grateful to Drs. Mike Bancroft and Masoud Kasrai of the Canadian Synchrotron Radiation Facility for collecting the XANES data and the staff of the Synchrotron Radiation Center (SRC), University of Wisconsin, Madison, for their technical support and the National Science Foundation (NSF) for supporting the SRC under Award #DMR-95-31009. NR 30 TC 7 Z9 7 U1 1 U2 1 PU SPRINGER/PLENUM PUBLISHERS PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1023-8883 J9 TRIBOL LETT JI Tribol. Lett. PD MAR PY 1998 VL 4 IS 2 BP 149 EP 154 DI 10.1023/A:1019159322826 PG 6 WC Engineering, Chemical; Engineering, Mechanical SC Engineering GA V17SJ UT WOS:000207956600010 ER PT J AU Jarrendahl, K Smith, SA Zheleva, T Kern, RS Davis, RF AF Jarrendahl, K Smith, SA Zheleva, T Kern, RS Davis, RF TI Growth of highly (0001)-oriented aluminum nitride thin films with smooth surfaces on silicon carbide by gas-source molecular beam epitaxy SO VACUUM LA English DT Article; Proceedings Paper CT 2nd Swedish Vacuum Meeting (SVM 2) CY AUG 18-20, 1997 CL LINKOPING UNIV, LINKOPING, SWEDEN SP Swedish Vacuum Sci, Int Union Vacuum Sci Technique & Applicat, Royal Swedish Acad Sci, Swedish Nat Sci Res Council, Swedish Res Council Engn Sci, Scienta Instruments, Thermo Instruments Nord AB, Fdn Strateg Res, Mat Res Consortium Thin Film Growth HO LINKOPING UNIV ID DEFECT FORMATION AB Aluminum nitride thin films with very smooth surfaces have been grown by gas-source molecular beam epitaxy on 4H and 6H silicon carbide substrates. High purity ammonia was used as the nitrogen source in conjunction with Al evaporated from an effusion cell. Streaked reflection high energy electron diffraction patterns and reconstructions of the AIN surfaces indicated smooth films. This surface character was confirmed via atomic force microscopy and transmission electron microscopy which showed roughness root mean square values typically below 1 nm and very flat surfaces, respectively X-ray diffraction showed the films to be highly c-axis oriented and single phase. Major impurities in the AIN films were oxygen and carbon, as revealed by secondary ion mass spectrometry. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 N Carolina State Univ, Dept Mat Sci & Engn, Raleigh, NC 27695 USA. USAF, Mat Directorate, Wright Patterson AFB, OH 45433 USA. RP Jarrendahl, K (reprint author), N Carolina State Univ, Dept Mat Sci & Engn, Box 7907, Raleigh, NC 27695 USA. EM kenneth-jarrendahl@ncsu.edu RI Davis, Robert/A-9376-2011; Jarrendahl, Kenneth/E-1807-2014 OI Davis, Robert/0000-0002-4437-0885; Jarrendahl, Kenneth/0000-0003-2749-8008 NR 18 TC 4 Z9 6 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0042-207X J9 VACUUM JI Vacuum PD MAR PY 1998 VL 49 IS 3 BP 189 EP 191 DI 10.1016/S0042-207X(97)00177-2 PG 3 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA ZF648 UT WOS:000072918100008 ER PT J AU Hall, TJ Reinke, DL Vonder Haar, TH AF Hall, TJ Reinke, DL Vonder Haar, TH TI Forecasting applications of high-resolution satellite cloud composite climatologies SO WEATHER AND FORECASTING LA English DT Article ID DIURNAL VARIABILITY; REGIONAL CLOUD; PARAMETERS AB In this paper, the authors describe experimental forecasting tools developed from high-resolution satellite cloud composites. The satellite data were extracted from the new 5-km, hourly, global satellite database called Climatological and Historical Analysis of Clouds for Environmental Simulations (CHANCES). Analysis was focused on a region over the former Yugoslavia and Adriatic Sea during summer 1994. Cloud composite images were constructed using digital infrared data for each hour of the day. The value at each pixel in the cloud composites was the fractional coverage of cloud at that location for the season and represented its systematic variation. Composite images were also constructed for conditional probabilities of cloud 1-12 h past each hour of the day. The values at any particular pixel in the composites represented the conditional probability of cloud given an initial condition of cloudy or clear in that pixel. Data from both types of composite images were combined to produce a climatological forecasting tool. Forecast tables were constructed of values for the pixel centered over Sarajevo. These tables are similar to the conditional climatology statistics familiar to forecasters in any weather station. A more sophisticated type of conditional probability was rested in which the initial condition was dependent on the average conditions of a region of pixels surrounding the Sarajevo pixel. Results demonstrate powerful operational applications of high-resolution satellite cloud climatologies. C1 Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 USA. RP Hall, TJ (reprint author), USAF, Combat Climatol Ctr, 151 Patton Ave,Room 120, Asheville, NC 28801 USA. RI Vonder Haar, Thomas/F-2048-2011; vonderhaar, thomas/N-6724-2015 OI vonderhaar, thomas/0000-0002-1962-7757 NR 16 TC 4 Z9 4 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD MAR PY 1998 VL 13 IS 1 BP 16 EP 23 DI 10.1175/1520-0434(1998)013<0016:FAOHRS>2.0.CO;2 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZF645 UT WOS:000072917800002 ER PT J AU McCarthy, DM AF McCarthy, DM TI Helicobacter pylori and non-steroidal anti-inflammatory drugs: Does infection affect the outcome of NSAID therapy? SO YALE JOURNAL OF BIOLOGY AND MEDICINE LA English DT Article; Proceedings Paper CT Helicobacter pylori Symposium CY MAR 01-02, 1997 CL NEW HAVEN, CONNECTICUT ID NONSTEROIDAL ANTIINFLAMMATORY DRUGS; PEPTIC-ULCER DISEASE; RHEUMATOID-ARTHRITIS; INDUCED GASTROPATHY; CHEMICAL GASTRITIS; DUODENAL-ULCER; RISK-FACTORS; INJURY; SEVERITY; NAPROXEN C1 USAF, Vet Adm Med Ctr 111F, Gastroenterol Sect, Albuquerque, NM 87108 USA. Univ New Mexico, Div Gastroenterol & Hepatol, Albuquerque, NM 87131 USA. RP McCarthy, DM (reprint author), USAF, Vet Adm Med Ctr 111F, Gastroenterol Sect, 2100 Ridgecrest Dr SE, Albuquerque, NM 87108 USA. NR 46 TC 6 Z9 6 U1 0 U2 0 PU YALE J BIOL MED INC PI NEW HAVEN PA 333 CEDAR ST, NEW HAVEN, CT 06510 USA SN 0044-0086 J9 YALE J BIOL MED JI Yale J. Biol. Med. PD MAR-APR PY 1998 VL 71 IS 2 BP 101 EP 111 PG 11 WC Biology; Medicine, General & Internal; Medicine, Research & Experimental SC Life Sciences & Biomedicine - Other Topics; General & Internal Medicine; Research & Experimental Medicine GA 205NC UT WOS:000080826600008 PM 10378355 ER PT J AU Talwar, DN Jogai, B Loehr, JP AF Talwar, DN Jogai, B Loehr, JP TI Novel type II strained layer superlattices for long wavelength infrared detectors SO MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY LA English DT Article; Proceedings Paper CT 2nd International Conference on Low Dimensional Structures and Devices CY MAY 19-21, 1997 CL LISBON, PORTUGAL DE novel type II (InAs)(Na)/(InxGa1-xSb)(Nb) superlattices; band-structure; long wavelength infrared detectors; tight-binding; kp; effective bond orbital model ID BAND-STRUCTURE; GA1-XINXSB/INAS SUPERLATTICES; ELECTRONIC-PROPERTIES; PHOTOLUMINESCENCE; ABSORPTION AB Novel type II (InAs)(Na)/(InxGa1-xSb)(Nb) short period strained layer superlattices (SLs) have shown considerable promise as candidates for applications in infrared imaging in the 10-12 mu m wavelength regions and beyond. Absorption alpha(h omega) calculations are difficult, however, because of the strong misalignment of the band edges of the two host materials at the interface and because of a large lattice mismatch. Theoretical studies of the energy band gaps and cut-off wavelengths in (InAs)(Na)/(InxGa1-xSb)(Nb) SLs grown on GaSb are reported as a function of composition and layer thickness using a modified second neighbor empirical tight-binding (ETBM), effective bond-orbital (EBOM) and 8 x 8 k,p models. The strain in the ETBM is included by scaling the matrix elements according to the Harrison's universal l/d(2) rule and by appropriately modifying the angular dependence. The EBOM and k,p calculations include the strain via the deformation theory. By appropriate choice of the In composition and layer thickness, cut-off wavelengths (lambda(c)) in the 10-12 mu m range are achievable. The study of alpha(h omega) for thin layer SLs in the k.p scheme suggest enhancement of absorption with increaing x at a fixed energy due to a large overlap of the electron-hole wavefunctions. (C) 1998 Elsevier Science S.A. All rights reserved. C1 Indiana Univ Penn, Dept Phys, Indiana, PA 15705 USA. Wright State Univ, Res Ctr, Dayton, OH 45435 USA. Wright Lab, Solid State Elect Directorate, Wright Patterson AFB, OH 45433 USA. RP Talwar, DN (reprint author), Indiana Univ Penn, Dept Phys, Indiana, PA 15705 USA. EM talwar@grove.iup.edu NR 25 TC 7 Z9 9 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5107 J9 MAT SCI ENG B-SOLID JI Mater. Sci. Eng. B-Solid State Mater. Adv. Technol. PD FEB 27 PY 1998 VL 51 IS 1-3 BP 12 EP 17 DI 10.1016/S0921-5107(97)00220-1 PG 6 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA ZD831 UT WOS:000072728800004 ER PT J AU Grady, EP Carpenter, MT Koenig, CD Older, SA Battafarano, DF AF Grady, EP Carpenter, MT Koenig, CD Older, SA Battafarano, DF TI Rheumatic findings in Gulf War veterans SO ARCHIVES OF INTERNAL MEDICINE LA English DT Article; Proceedings Paper CT 59th Annual Scientific Meeting of the American-College-of-Rheumatology CY OCT 25, 1995 CL SAN FRANCISCO, CALIFORNIA SP Amer Coll Rheumatol ID PREDICTIVE VALUE; CIVIL-WAR; PREVALENCE; SYMPTOMS; DISEASE; THERAPY; SEROLOGY AB Background: Rheumatic symptoms were commonly described among soldiers who served in previous wars. Objective: To describe the frequency of rheumatology consultations, along with the diagnoses, and abnormal results on serologic testing in Gulf War veterans evaluated for Gulf War syndrome. Methods: The medical records of the first 250 consecutive Gulf War veterans referred to the comprehensive clinical evaluation program at Wilford Hall Air Force Medical Center and Brooke Army Medical Center, San Antonio, Tex, were reviewed for demographic characteristics and frequency of subspecialty consultations. A retrospective review of rheumatic diagnoses and the frequency of abnormal serologic test results was recorded. Results: Of the 250 Gulf War veterans evaluated in the comprehensive clinical evaluation program, 139 (56%) were referred for rheumatology consultation, which was the most common elective subspecialty referral. Of the patients evaluated, 82 (59%) had soft tissue syndromes, 19 (14%) had rheumatic disease, and 38 (27%) had no rheumatic disease. The most common soft tissue syndromes were patellofemoral syndrome (33 patients [25%]), mechanical low back pain (23 patients [18%]), and fibromyalgia (22 patients [17%]). Of the 19 patients with rheumatic disease, 10 had osteoarthritis, 2 had rheumatoid arthritis, 2 had gout, and 1 each had systemic lupus erythematosus, Behcet disease, parvovirus arthritis, psoriatic arthritis, and hypothyroid arthropathy. Abnormal serologic test results were common among the Gulf War patients regardless of the presence or absence of rheumatic disease. Conclusions: The rheumatic manifestations in Gulf War veterans are similar to symptoms and diagnoses described in previous wars and are not unique to active duty soldiers. Overall, the results of serologic screening were poor predictors of the presence of rheumatic disease. C1 Brooke Army Med Ctr, Dept Med, Rheumatol Serv, San Antonio, TX 78234 USA. Brooke Army Med Ctr, Internal Med Serv, San Antonio, TX 78234 USA. Wilford Hall USAF Med Ctr, Rheumatol Serv, San Antonio, TX 78236 USA. RP Battafarano, DF (reprint author), Brooke Army Med Ctr, Dept Med, Rheumatol Serv, San Antonio, TX 78234 USA. NR 33 TC 19 Z9 20 U1 1 U2 1 PU AMER MEDICAL ASSOC PI CHICAGO PA 515 N STATE ST, CHICAGO, IL 60610 USA SN 0003-9926 J9 ARCH INTERN MED JI Arch. Intern. Med. PD FEB 23 PY 1998 VL 158 IS 4 BP 367 EP 371 DI 10.1001/archinte.158.4.367 PG 5 WC Medicine, General & Internal SC General & Internal Medicine GA YY366 UT WOS:000072139900007 PM 9487234 ER PT J AU Tang, JK Feng, L Zabinski, JS AF Tang, JK Feng, L Zabinski, JS TI The effects of metal interlayer insertion on the friction, wear and adhesion of TiC coatings SO SURFACE & COATINGS TECHNOLOGY LA English DT Article; Proceedings Paper CT 24th International Conference on Metallurgical Coatings and Thin Films (ICMCTF 97) CY APR 21-25, 1997 CL SAN DIEGO, CALIFORNIA SP Amer Vacuum Soc, Vacuum Met & Thin Films Div DE adhesion; friction; interlayer; TiC coating; wear ID TITANIUM CARBIDE AB TIC coatings on 440C stainless steel (SS) substrates that contain different kinds of interlayers (Ti, Cr and Mo) of different thickness were grown by magnetron sputtering. The friction; wear and adhesion behaviors were investigated for the TIC coatings using pin-on-disk configuration. The wear tracks of the TIC coatings and alumina pin were characterized by optical microscope or scanning electron microscope (SEM), Inserting Cr or Ti interlayer between TiC coating and substrate could improve greatly the wear, hardness and adhesion. In wear tests the TIC coating with Cr interlayer usually showed better characteristics than that with Ti interlayer. In addition, the TIC coating with 50 nm Ti interlayer performed better than that with 500 nm Ti interlayer in the adhesion and wear tests. It is noticed that the TiC coating could not be improved on the friction and wear behavior when metallic Mo was inserted between the TiC and substrate resulting from the poor adhesion of the coating. (C) 1998 Elsevier Science S.A. C1 Univ New Orleans, Dept Phys, New Orleans, LA 70148 USA. USAF, Wright Lab, MLBT, Wright Patterson AFB, Cleveland, OH 45433 USA. RP Tang, JK (reprint author), Univ New Orleans, Dept Phys, New Orleans, LA 70148 USA. EM jxtph@uno.edu NR 8 TC 24 Z9 25 U1 0 U2 5 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0257-8972 J9 SURF COAT TECH JI Surf. Coat. Technol. PD FEB 23 PY 1998 VL 99 IS 3 BP 242 EP 247 DI 10.1016/S0257-8972(97)00570-7 PG 6 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA ZF909 UT WOS:000072945400004 ER PT J AU Laube, SJP Voevodin, AA Korenyi-Both, A AF Laube, SJP Voevodin, AA Korenyi-Both, A TI Cathodic arc titanium nitride in situ process feedback control for multi-layer deposition SO SURFACE & COATINGS TECHNOLOGY LA English DT Article DE arc; control; in situ; tin ID COATINGS AB Increases in thin film coating process-quality standard requirements, such as the national aerospace defense contractors accreditation program (NADCAP) and ISO9000 have forced improvements in existing deposition process technology. Improved process traceability and performance are now required. In situ process-control of cathodic arcs provides a method of consistent film deposition by unmasking internal process dynamics that are otherwise not observed by sensors at the process boundaries. Increased film quality and yield is realized, utilizing plasma emission spectroscopy for in situ feedback control. The feedback control was demonstrated to stabilize process performance, enabling repeatable runs and reduction of coating contamination. (C) 1998 Elsevier Science S.A. C1 USAF, Wright Lab, MLIM, Wright Patterson AFB, Cleveland, OH 45433 USA. USAF, Wright Lab, MLBT, Mat Directorate,Wright Patterson AFB, Cleveland, OH 45433 USA. Hohman Plating & Mfg Inc, Dayton, OH 45404 USA. RP Laube, SJP (reprint author), USAF, Wright Lab, MLIM, Wright Patterson AFB, Bldg 653,2977 P St,Ste 13, Cleveland, OH 45433 USA. EM laubesjp@ml.wpafb.af.mil RI Voevodin, Andrey/I-6684-2013 NR 12 TC 3 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0257-8972 J9 SURF COAT TECH JI Surf. Coat. Technol. PD FEB 23 PY 1998 VL 99 IS 3 BP 281 EP 286 DI 10.1016/S0257-8972(97)00571-9 PG 6 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA ZF909 UT WOS:000072945400010 ER PT J AU Egan, MP Shipman, RF Price, SD Carey, SJ Clark, FO Cohen, M AF Egan, MP Shipman, RF Price, SD Carey, SJ Clark, FO Cohen, M TI A population of cold cores in the Galactic plane SO ASTROPHYSICAL JOURNAL LA English DT Article DE dust, extinction; Galaxy, center; infrared, general; infrared, ISM, continuum; ISM, clouds ID MIDCOURSE SPACE EXPERIMENT AB Recent observations by the Midcourse Space Experiment (MSX) have revealed the presence of compact objects seen in absorption against bright mid-infrared emission from the Galactic plane. Examination of MSX and IRAS images of these objects reveal that they an dark from 7 to 100 mu m. We find similar to 2000 clouds in a 1 degrees x 180 degrees scan along the Galactic equator. The data suggest these objects are dense (n > 10(5) cm(-3)), cold (T < 20 K) cores, without accompanying envelopes. C1 USAF, Res Lab, VSBC, Hanscom AFB, MA 01731 USA. Univ Calif Berkeley, Radio Astron Lab, Berkeley, CA 94720 USA. RP Egan, MP (reprint author), USAF, Res Lab, VSBC, 29 Randolph Rd, Hanscom AFB, MA 01731 USA. NR 16 TC 220 Z9 222 U1 1 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5801 S ELLIS AVENUE, CHICAGO, IL 60637 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD FEB 20 PY 1998 VL 494 IS 2 BP L199 EP + DI 10.1086/311198 PN 2 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA YZ797 UT WOS:000072292600017 ER PT J AU Arnold, ST Morris, RA Viggiano, AA AF Arnold, ST Morris, RA Viggiano, AA TI Reactions of O- with various alkanes: Competition between hydrogen abstraction and reactive detachment SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID TRAJECTORY CALCULATIONS; ENERGY AB We have studied the rate constants and product branching percentages of the reactions of O- with a large number of alkanes: ethane, propane, butane, isobutane (2-methylpropane), pentane, isopentane (2-methylbutane), neopentane (2,2-dimethylpropane), hexane, heptane, octane, isooctane (2,2,4-trimethylpentane), decane, and dodecane. The efficiencies for the reactions of O- with ethane, propane, and butane increase with increasing size, becoming collisional for butane at room temperature. A small temperature dependence is found. For pentane and larger alkanes, the reactions are collisional at all temperatures, within our uncertainty. In contrast to a previous study, there are two significant reaction channels observed: a hydrogen abstraction channel yielding OH- and a reactive detachment channel yielding neutral products and a free electron. In the normal alkane series, the fraction of OH- produced decreases exponentially with,increasing polarizability, i.e., alkane size. Isobutane and isopentane react similarly to their normal alkane counterparts, while isooctane and neopentane produce significantly more OH- than octane and pentane, respectively. Taken together, the branching fraction results indicate that the reactive detachment channel is due to abstraction of two hydrogen atoms from adjacent carbons within the alkane. C1 USAF, Res Lab, Space Vehicles Directorate, Hanscom AFB, MA 01731 USA. RP Viggiano, AA (reprint author), USAF, Res Lab, Space Vehicles Directorate, 29 Randolph Rd, Hanscom AFB, MA 01731 USA. NR 11 TC 16 Z9 16 U1 2 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD FEB 19 PY 1998 VL 102 IS 8 BP 1345 EP 1348 DI 10.1021/jp9733429 PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA YY566 UT WOS:000072161000015 ER PT J AU Clark, WD AF Clark, WD TI Otology - Temporal bone dissector: The interactive otology reference SO JAMA-JOURNAL OF THE AMERICAN MEDICAL ASSOCIATION LA English DT Software Review C1 Univ Texas, Hlth Sci Ctr, Wilford Hall USAF Med Ctr, San Antonio, TX 78284 USA. RP Clark, WD (reprint author), Univ Texas, Hlth Sci Ctr, Wilford Hall USAF Med Ctr, San Antonio, TX 78284 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU AMER MEDICAL ASSOC PI CHICAGO PA 515 N STATE ST, CHICAGO, IL 60610 USA SN 0098-7484 J9 JAMA-J AM MED ASSOC JI JAMA-J. Am. Med. Assoc. PD FEB 18 PY 1998 VL 279 IS 7 BP 558 EP 558 DI 10.1001/jama.279.7.558 PG 1 WC Medicine, General & Internal SC General & Internal Medicine GA YW470 UT WOS:000071938900044 ER PT J AU Ongstad, AP Dente, GC Tilton, ML Stohs, J Gallant, DJ AF Ongstad, AP Dente, GC Tilton, ML Stohs, J Gallant, DJ TI Determination of carrier lifetimes using Hakki-Paoli gain data SO APPLIED PHYSICS LETTERS LA English DT Article ID QUANTUM-WELL LASERS; RECOMBINATION AB This letter presents a technique for determining carrier lifetimes, which does not require a fast detector or rely on an experimentally complex implementation. The technique is based both on a measurement and a parallel calculation: (1) A Hakki-Paoli [J. Appl. Phys. 44, 4113 (1973)] measurement of modal gain versus current density, g (J), and (2) a theoretical determination of the modal gain versus carrier sheet density, g(N). Once the gain relationships have been determined, the carrier sheet density N can be functionally related to the current density J and the lifetime determined. We demonstrate this method on two InGaAs single quantum well lasers. This method may prove particularly useful for carrier lifetime estimations in long-wavelength semiconductor lasers. (C) 1998 American Institute of Physics. C1 USAF, Phillips Lab, Kirtland AFB, NM 87117 USA. Boeing N Amer, Rocketdyne Tech Serv, Albuquerque, NM 87185 USA. GCD Associates, Albuquerque, NM 87110 USA. Univ New Mexico, Ctr High Technol Mat, Albuquerque, NM 87131 USA. RP Ongstad, AP (reprint author), USAF, Phillips Lab, Kirtland AFB, NM 87117 USA. NR 14 TC 1 Z9 1 U1 1 U2 6 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD FEB 16 PY 1998 VL 72 IS 7 BP 836 EP 838 DI 10.1063/1.120909 PG 3 WC Physics, Applied SC Physics GA ZH583 UT WOS:000073126000029 ER PT J AU Schaffer, LG Phillips, MD AF Schaffer, LG Phillips, MD TI Oral immunosuppressive therapy for acquired hemophilia - In response SO ANNALS OF INTERNAL MEDICINE LA English DT Letter C1 Wilford Hall USAF Med Ctr, Lackland AFB, TX 77030 USA. Centeon, King Of Prussia, PA 19406 USA. RP Schaffer, LG (reprint author), Wilford Hall USAF Med Ctr, Lackland AFB, TX 77030 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER COLL PHYSICIANS PI PHILADELPHIA PA INDEPENDENCE MALL WEST 6TH AND RACE ST, PHILADELPHIA, PA 19106-1572 USA SN 0003-4819 J9 ANN INTERN MED JI Ann. Intern. Med. PD FEB 15 PY 1998 VL 128 IS 4 BP 325 EP 325 PG 1 WC Medicine, General & Internal SC General & Internal Medicine GA YX170 UT WOS:000072013400029 ER PT J AU Ruggiu, JM Solomon, CJ Loos, G AF Ruggiu, JM Solomon, CJ Loos, G TI Gram-Charlier matched filter for Shack-Hartmann sensing at low light levels SO OPTICS LETTERS LA English DT Article ID ACCURACY CENTROID ESTIMATION; SYSTEMATIC-ERROR; ELIMINATION AB A study has been made of a Gram-Charlier matched filter for Shack-Hartmann sensing of wave-front slopes. The method is based on modeling the point-spread function by an expansion in terms of Gauss-Hermite polynomials. We present results for several subaperture/coherence area sizes both with and without CCD read noise. A more accurate estimation of the local slopes can be. achieved at low light levels in this way than with the standard first-moment estimator. (C) 1998 Optical Society of America. C1 Univ Kent, Dept Phys, Canterbury CT2 7NR, Kent, England. USAF, Phillips Lab, Kirtland AFB, NM 87117 USA. RP Ruggiu, JM (reprint author), Univ Kent, Dept Phys, Canterbury CT2 7NR, Kent, England. NR 15 TC 8 Z9 8 U1 0 U2 1 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD FEB 15 PY 1998 VL 23 IS 4 BP 235 EP 237 DI 10.1364/OL.23.000235 PG 3 WC Optics SC Optics GA YX558 UT WOS:000072052600001 PM 18084470 ER PT J AU Brigantic, RT Roggemann, MC Welsh, BM Bauer, KW AF Brigantic, RT Roggemann, MC Welsh, BM Bauer, KW TI Optimization of adaptive-optics systems closed-loop bandwidth settings to maximize imaging-system performance SO APPLIED OPTICS LA English DT Article ID ATMOSPHERIC-TURBULENCE; GUIDE-STAR; TELESCOPES; DESIGN AB We present the results of research aimed at optimizing adaptive-optics closed-loop bandwidth settings to maximize imaging-system performance, The optimum closed-loop bandwidth settings are determined as a function of target-object Light levels and atmospheric seeing conditions. Our work shows that; for bright objects, the optimum closed-loop bandwidth is near the Greenwood frequency. However, for dim objects without the Use Of a laser beacon the preferred closed-loop bandwidth settings are a small fraction of the Greenwood frequency. In addition, under low light levels selection of the proper closed-loop bandwidth is more critical for achieving maximum performance than it is under high light levels. We also present a strategy for selecting the closed-loop bandwidth to provide robust system performance for different target-object light levels, (C) 1998 Optical Society of America. C1 USAF, Inst Technol, Dept Operat Sci, Wright Patterson AFB, OH 45433 USA. Michigan Technol Univ, Dept Elect Engn, Houghton, MI 49931 USA. Mission Res Corp, Dayton, OH 45430 USA. RP Brigantic, RT (reprint author), USAF, Inst Technol, Dept Operat Sci, 2950 P St, Wright Patterson AFB, OH 45433 USA. NR 11 TC 4 Z9 4 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD FEB 10 PY 1998 VL 37 IS 5 BP 848 EP 855 DI 10.1364/AO.37.000848 PG 8 WC Optics SC Optics GA YV739 UT WOS:000071857900006 PM 18268662 ER PT J AU Peterkin, RE Frese, MH Sovinec, CR AF Peterkin, RE Frese, MH Sovinec, CR TI Transport of magnetic flux in an arbitrary coordinate ALE code SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article ID ACCELERATION AB We illustrate a new technique for computing the. time-evolution of magnetic flux on a generally nonorthogonal computational grid of a time-dependent, arbitrary Lagrangian-Eulerian magnetohydrodynamics (MHD) simulation code and apply this technique to some classical MHD test problems. For a nontrivial application, we demonstrate the power of this technique for the interesting problem of compact toroid translation between a pair of converging conical electrodes. (C) 1998 Academic Press. C1 USAF, Directed Energy Directorate, Res Lab, Phillips Lab, Kirtland AFB, NM 87117 USA. NumerEx, Albuquerque, NM 87106 USA. RP Peterkin, RE (reprint author), USAF, Directed Energy Directorate, Res Lab, Phillips Lab, Kirtland AFB, NM 87117 USA. RI Frese, Michael/B-3283-2014 NR 14 TC 81 Z9 82 U1 1 U2 7 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9991 J9 J COMPUT PHYS JI J. Comput. Phys. PD FEB 10 PY 1998 VL 140 IS 1 BP 148 EP 171 DI 10.1006/jcph.1998.5880 PG 24 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA ZD984 UT WOS:000072745400007 ER PT J AU Wang, ZQ Day, PN Pachter, R AF Wang, ZQ Day, PN Pachter, R TI Density functional theory studies of meso-alkynyl porphyrins SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID FREE-BASE PORPHYRINS; IONIZATION-POTENTIALS; POLYATOMIC-MOLECULES; OPTICAL-PROPERTIES; STATES; PHTHALOCYANINE; ACCURATE; ENERGIES; LIMITER; SPECTRA AB Geometry optimizations and electronic structure calculations are reported for porphyrins with meso-acetylene substituents using density functional theory (DFT). The addition of the acetylene group alters the nearest C-C bond length in the porphyrin ring by 0.01 to 0.02 Angstrom, but the molecule retains its D-2h symmetry. The calculated electronic structures clearly show that the acetylene group contributes to the pi-electron conjugation along the porphyrin ring for the HOMO and LUMO, and reduces significantly the HOMO-LUMO gap, being consistent with experimental results [H. L. Anderson, Tetrahedron Lett. 33, 101 (1992)]. The core ionization potential (IF) of the central nitrogen calculated using the so-called local density approximation effective core (LDAEC) method, is increased by 0.24 eV, indicating a more positive electrostatic potential than in PH2. LDA-Delta SCF results for the first three valence IPs indicate changes of 0.1 to 0.2 cV relative to those of the free-base porphin, with the gap between the first and second IPs being over twice as large in the acetylated molecule. The protective trimethylsilyl (TMS) group further reduces the HOMO-LUMO gap, but by a small amount. (C) 1998 American Institute of Physics. C1 USAF, Res Lab, Mat & Mfg Directorate, AFRL,MLPJ, Wright Patterson AFB, OH 45433 USA. RP Wang, ZQ (reprint author), USAF, Res Lab, Mat & Mfg Directorate, AFRL,MLPJ, Wright Patterson AFB, OH 45433 USA. NR 31 TC 27 Z9 28 U1 1 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD FEB 8 PY 1998 VL 108 IS 6 BP 2504 EP 2510 DI 10.1063/1.475633 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA YV251 UT WOS:000071804500027 ER PT J AU Keesling, CA Frush, DP O'Hara, SM Fordham, LA AF Keesling, CA Frush, DP O'Hara, SM Fordham, LA TI Clinical and imaging manifestations of pediatric sarcoidosis SO ACADEMIC RADIOLOGY LA English DT Article ID PULMONARY SARCOIDOSIS; CNS SARCOIDOSIS; YOUNG-CHILDREN; HEART-DISEASE; MR; CT; NEUROSARCOIDOSIS; CHILDHOOD C1 Duke Univ, Med Ctr, Dept Radiol, Durham, NC 27710 USA. Univ N Carolina Hosp, Dept Radiol, Chapel Hill, NC USA. RP Keesling, CA (reprint author), Wilford Hall USAF Med Ctr, 59th Med Wing MTRD,2200 Bergquist Dr,Ste 1, Lackland AFB, TX 78236 USA. RI Frush, Donald/M-6457-2015 OI Frush, Donald/0000-0002-6928-4465 NR 45 TC 10 Z9 10 U1 0 U2 0 PU ASSOC UNIV RADIOLOGISTS PI OAK BROOK PA 2021 SPRING RD, STE 600, OAK BROOK, IL 60521 USA SN 1076-6332 J9 ACAD RADIOL JI Acad. Radiol. PD FEB PY 1998 VL 5 IS 2 BP 122 EP 132 DI 10.1016/S1076-6332(98)80134-7 PG 11 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA ZH426 UT WOS:000073107800012 PM 9484547 ER PT J AU Ockner, DM Ritter, JH Swanson, PE Wick, MR AF Ockner, DM Ritter, JH Swanson, PE Wick, MR TI Magnification of electron micrographs - Reply SO AMERICAN JOURNAL OF CLINICAL PATHOLOGY LA English DT Letter C1 Wilford Hall USAF Med Ctr, Lackland AFB, TX 78236 USA. Washington Univ, Sch Med, St Louis, MO USA. RP Ockner, DM (reprint author), Wilford Hall USAF Med Ctr, Lackland AFB, TX 78236 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC CLIN PATHOLOGISTS PI CHICAGO PA 2100 W HARRISON ST, CHICAGO, IL 60612 USA SN 0002-9173 J9 AM J CLIN PATHOL JI Am. J. Clin. Pathol. PD FEB PY 1998 VL 109 IS 2 BP 238 EP 238 PG 1 WC Pathology SC Pathology GA YU743 UT WOS:000071749800019 ER PT J AU Breitigan, JM AF Breitigan, JM TI Counseling about chlorofluorocarbon-free inhalers SO AMERICAN JOURNAL OF HEALTH-SYSTEM PHARMACY LA English DT Editorial Material C1 USAF, Pharm Flight Biomed Sci Corps, Wright Patterson AFB, OH 45433 USA. RP Breitigan, JM (reprint author), USAF, Pharm Flight Biomed Sci Corps, 74th MDSS SGSP,4881 Sugar Maple Dr, Wright Patterson AFB, OH 45433 USA. NR 5 TC 1 Z9 1 U1 0 U2 0 PU AMER SOC HEALTH-SYSTEM PHARMACISTS PI BETHESDA PA 7272 WISCONSIN AVE, BETHESDA, MD 20814 USA SN 1079-2082 J9 AM J HEALTH-SYST PH JI Am. J. Health-Syst. Pharm. PD FEB 1 PY 1998 VL 55 IS 3 BP 226 EP 227 PG 2 WC Pharmacology & Pharmacy SC Pharmacology & Pharmacy GA YX156 UT WOS:000072012000008 PM 9492253 ER PT J AU Johnson, CE Johnson, SP Taylor, JC AF Johnson, CE Johnson, SP Taylor, JC TI Common origin of left vertebral and left internal carotid artery SO AMERICAN JOURNAL OF ROENTGENOLOGY LA English DT Article C1 Wilford Hall USAF Med Ctr, Lackland AFB, TX 78236 USA. RP Johnson, CE (reprint author), Wilford Hall USAF Med Ctr, Lackland AFB, TX 78236 USA. NR 4 TC 4 Z9 4 U1 0 U2 0 PU AMER ROENTGEN RAY SOC PI RESTON PA 1891 PRESTON WHITE DR, SUBSCRIPTION FULFILLMENT, RESTON, VA 22091 USA SN 0361-803X J9 AM J ROENTGENOL JI Am. J. Roentgenol. PD FEB PY 1998 VL 170 IS 2 BP 514 EP 514 PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA YT562 UT WOS:000071619500068 PM 9456985 ER PT J AU Weesner, KA Waisel, DB AF Weesner, KA Waisel, DB TI A "circle system" adaptation of the Hotline fluid warmer is effective for small volumes SO ANESTHESIA AND ANALGESIA LA English DT Meeting Abstract C1 Wilford Hall USAF Med Ctr, Dept Anesthesiol, Lackland AFB, TX 78236 USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 USA SN 0003-2999 J9 ANESTH ANALG JI Anesth. Analg. PD FEB PY 1998 VL 86 IS 2S SU S MA S244 PG 1 WC Anesthesiology SC Anesthesiology GA YV675 UT WOS:000071851500243 ER PT J AU Tracy, JM Demain, JG Hoffman, KM Goetz, DW AF Tracy, JM Demain, JG Hoffman, KM Goetz, DW TI Intranasal beclomethasone as an adjunct to treatment of chronic middle ear effusion SO ANNALS OF ALLERGY ASTHMA & IMMUNOLOGY LA English DT Article ID CHRONIC OTITIS-MEDIA; DOUBLE-BLIND CROSSOVER; EUSTACHIAN-TUBE; TRIMETHOPRIM-SULFAMETHOXAZOLE; DIPROPIONATE AEROSOL; ALLERGIC RHINITIS; CHILDREN; MANAGEMENT; PREDNISONE; EFFICACY AB Background: Following otitis media, 10% to 50% of children develop residual middle ear effusion with concurrent hearing loss and potential cognitive, behavioral, and language impairment. Prophylactic antibiotics and tympanostomy tubes are currently recommended treatments for chronic middle ear effusion. Objective: In a double-blind, placebo-controlled, randomized study of chronic middle ear effusion, we assessed the effectiveness of topical intranasal beclomethasone as an adjunct to prophylactic antibiotic therapy. Methods: Sixty-one children, aged 3 to 11 years with persistent middle ear effusion greater than 3 months, were randomized into three treatment groups: (1) prophylactic antibiotics; (2) prophylactic antibiotics plus intranasal beclomethasone (336 mu g/day); and (3) prophylactic antibiotics plus intranasal placebo. Patients were evaluated with aeroallergen skin tests at entry; and tympanogram, otoscopic examination, and symptom questionnaire at 0, 4, 8, and 12 weeks. Results: While middle ear pressures, otoscopic examinations, and symptom scores were improved for each treatment group over 12 weeks of therapy, the beclomethasone plus antibiotics group improved all three measures more rapidly than the antibiotics-alone and placebo nasal spray plus antibiotics groups over the first 8 weeks. Only the beclomethasone group significantly improved left (P = .004) and right (P = .01) middle ear pressures over 12 weeks. Resolution of chronic middle ear effusions was more frequent in the beclomethasone group (P less than or equal to .05 at 3 and 8 weeks). No difference in response to nasal steroids was observed between atopic and nonatopic subjects. Conclusions: We conclude that intranasal beclomethasone may be a useful adjunct to prophylactic antibiotic treatment of chronic middle ear effusion. C1 Wilford Hall USAF Med Ctr, Dept Allergy Immunol, Lackland AFB, TX 78236 USA. Wilford Hall USAF Med Ctr, Dept Pediat, Lackland AFB, TX 78236 USA. RP Goetz, DW (reprint author), Wilford Hall USAF Med Ctr, Dept Allergy Immunol, 59MDW-MMIA,2200 Bergquist Dr,Suite 1, Lackland AFB, TX 78236 USA. NR 40 TC 40 Z9 43 U1 0 U2 1 PU AMER COLL ALLERGY ASTHMA IMMUNOLOGY PI ARLINGTON HTS PA 85 WEST ALGONQUIN RD SUITE 550, ARLINGTON HTS, IL 60005 USA SN 1081-1206 J9 ANN ALLERG ASTHMA IM JI Ann. Allergy Asthma Immunol. PD FEB PY 1998 VL 80 IS 2 BP 198 EP 206 PG 9 WC Allergy; Immunology SC Allergy; Immunology GA YZ485 UT WOS:000072258800011 PM 9494455 ER PT J AU Spiess, T Desiere, F Fischer, P Spain, JC Knackmuss, HJ Lenke, H AF Spiess, T Desiere, F Fischer, P Spain, JC Knackmuss, HJ Lenke, H TI A new 4-nitrotoluene degradation pathway in a Mycobacterium strain SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Article ID PSEUDOMONAS-PSEUDOALCALIGENES; BIODEGRADATION; 2-NITROTOLUENE; OXIDATION; CLEAVAGE AB Mycobacterium sp, strain HL 4-NT-1, isolated from a mixed soil sample from the Stuttgart area, utilized 4-nitrotoluene as the sole source of nitrogen, carbon, and energy. Under aerobic conditions, resting cells of the Mycobacterium strain metabolized 4-nitrotoluene with concomitant release of small amounts of ammonia; under anaerobic conditions, 4-nitrotoluene was completely converted to 6-amino-m-cresol. 4-Hydroxylaminotoluene was converted to 6-amino-m-cresol by cell extracts and thus could be confirmed as the initial metabolite in the degradative pathway, This ;enzymatic equivalent to the acid-catalyzed Bamberger rearrangement requires neither cofactors nor oxygen. In the same crucial enzymatic step. the homologous substrate hydroxylaminobenzene was rearranged to 2-aminophenol., Abiotic oxidative dimerization of 6-amino-m-cresol, observed during growth of the Mycobacterium strain, yielded a yellow dihydrophenoxazinone. Another yellow metabolite (lambda(max),,,, 385 nm) was tentatively identified as ?2-amino-5-methylmuconic semialdehyde, formed from 6-amino-m-cresol by meta ring cleavage. C1 Fraunhofer Inst Grenzflachen & Bioverfahrenstech, D-70569 Stuttgart, Germany. Univ Stuttgart, Inst Organ Chem, D-70569 Stuttgart, Germany. Univ Stuttgart, Inst Mikrobiol, D-70569 Stuttgart, Germany. Armstrong Lab, EQ OL, Tyndall AFB, FL 32403 USA. RP Lenke, H (reprint author), Fraunhofer Inst Grenzflachen & Bioverfahrenstech, Nobelstr 12, D-70569 Stuttgart, Germany. NR 29 TC 46 Z9 49 U1 1 U2 5 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 USA SN 0099-2240 J9 APPL ENVIRON MICROB JI Appl. Environ. Microbiol. PD FEB PY 1998 VL 64 IS 2 BP 446 EP 452 PG 7 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA YV746 UT WOS:000071858600010 PM 9464378 ER PT J AU Alfano, AJ AF Alfano, AJ TI Hybrid photomultiplier: Its characterization and application as a wide-dynamic-range photon detector SO APPLIED SPECTROSCOPY LA English DT Article DE hybrid photomultiplier tube; photomultiplier tube gating; photon detection ID PLATE PHOTOMULTIPLIERS; AVALANCHE-DIODE; PHOTODIODE TUBE; LIGHT DETECTOR; RESOLUTION; SYSTEM AB The hybrid photomultiplier (HPMT) is commercially available in proximity-and electrostatically focused versions, and both contain a photocathode and a PIN-diode substrate. This recent addition to the family of photon detectors offers good timing characteristics, reasonable gain, excellent pulse height distribution, and a wide dynamic range. This report provides details on the wiring and characterization of a typical electrostatically focused production device for gain, impulse response, and pulse height and pulse integral linearity. A gain of 1.8 x 10(3) was obtained at less than the maximum high-voltage bias. The impulse response rise time was 1.0 ns and the fall time was 0.9 ns. The full width at half-maximum (FWHM) of the impulse response was 4.3 ns at 160 V reverse diode bias. The pulse height was linear up to 4.45 x 10(4) photoelectrons, and the pulse integral was linear up to the maximum tested (2.23 x 10(5) photoelectrons). The HPMT is not damaged by light levels that are three orders of magnitude beyond the range of linear response for a conventional PMT. Therefore, the HPMT can be directly implemented in spectroscopic applications that previously required elaborate gating schemes to protect a detector from a large optical flash that preceeds a weak subsequent optical event of interest. C1 USAF, Res Lab, Hughes STX, AFRL PRS, Edwards AFB, CA 93524 USA. RP Alfano, AJ (reprint author), USAF, Res Lab, Hughes STX, AFRL PRS, 10 E Saturn Blvd, Edwards AFB, CA 93524 USA. NR 22 TC 1 Z9 1 U1 0 U2 0 PU SOC APPLIED SPECTROSCOPY PI FREDERICK PA 201B BROADWAY ST, FREDERICK, MD 21701 USA SN 0003-7028 J9 APPL SPECTROSC JI Appl. Spectrosc. PD FEB PY 1998 VL 52 IS 2 BP 303 EP 307 DI 10.1366/0003702981943400 PG 5 WC Instruments & Instrumentation; Spectroscopy SC Instruments & Instrumentation; Spectroscopy GA ZF981 UT WOS:000072952600023 ER PT J AU Fisher, MS Rush, WL Rosado-de-Christenson, ML Goldstein, ER Tomski, SM Wempe, JM Travis, WD AF Fisher, MS Rush, WL Rosado-de-Christenson, ML Goldstein, ER Tomski, SM Wempe, JM Travis, WD TI Diffuse panbronchiolitis - Histologic diagnosis in unsuspected cases involving North American residents of Asian descent SO ARCHIVES OF PATHOLOGY & LABORATORY MEDICINE LA English DT Article ID BRONCHOALVEOLAR LAVAGE FLUID; ERYTHROMYCIN; LUNG AB Objective.-To study and report two cases of diffuse panbronchiolitis in patients of Asian ancestry residing in the United States and to review the literature pertaining to this disease. Design.-Diffuse panbronchiolitis is a progressive interstitial pneumonitis occurring primarily in Japan. Rare cases are now being identified in Europe and North America. Patients often have a history of sinusitis, present with dyspnea on exertion, and show a restrictive pattern on pulmonary function tests. The clinical, radiologic, and pathologic features of two cases of the disease received for consultation at the Armed Forces Institute of Pathology, Washington, DC, are reported with a review of the literature. Results.-Chest radiographs revealed bilateral small nodular opacities with ill-defined borders. High-resolution computed tomography demonstrated the abnormalities to have a centrilobular distribution. Histologically, there was transmural chronic inflammation centered on the terminal bronchioles and an interstitial infiltrate of foamy macrophages. Conclusion.-Diffuse panbronchiolitis may be mistaken for other more common small airway diseases and may be underrecognized in Western nations. The immigration of Asians and sporadic case reports involving non-Asians make recognition of this disease entity important, as the implications for therapy are different than that of other small airway diseases. C1 Armed Forces Inst Pathol, Dept Pulm & Mediastinal Pathol, Washington, DC 20306 USA. Wilford Hall USAF Med Ctr, Dept Pathol, Lackland AFB, TX 78236 USA. Uniformed Serv Univ Hlth Sci, Dept Radiol & Nucl Med, Bethesda, MD 20814 USA. George Washington Univ, Sch Med, Dept Clin Med, Washington, DC 20052 USA. David Grant Med Ctr, Dept Pulm Med, Travis AFB, CA USA. USAF Acad, Med Ctr, Denver, CO USA. RP Rush, WL (reprint author), Armed Forces Inst Pathol, Dept Pulm & Mediastinal Pathol, 6825 NW 16th St, Washington, DC 20306 USA. NR 28 TC 15 Z9 15 U1 0 U2 0 PU COLLEGE AMER PATHOLOGISTS PI NORTHFIELD PA C/O KIMBERLY GACKI, 325 WAUKEGAN RD, NORTHFIELD, IL 60093-2750 USA SN 0003-9985 J9 ARCH PATHOL LAB MED JI Arch. Pathol. Lab. Med. PD FEB PY 1998 VL 122 IS 2 BP 156 EP 160 PG 5 WC Medical Laboratory Technology; Medicine, Research & Experimental; Pathology SC Medical Laboratory Technology; Research & Experimental Medicine; Pathology GA YW354 UT WOS:000071926600008 PM 9499359 ER PT J AU Schwertner, HA AF Schwertner, HA TI Association of smoking and low serum bilirubin antioxidant concentrations SO ATHEROSCLEROSIS LA English DT Article DE cigarette smoking; bilirubin; coronary artery disease; antioxidants; risk factors ID LOW-DENSITY-LIPOPROTEIN; ALBUMIN-BOUND BILIRUBIN; LIPID-PEROXIDATION; SMOKERS; OXIDATION; PLASMA; MODULATION; RISK AB This study sought to examine the association between cigarette smoking and serum bilirubin antioxidant concentrations in 715 middle-aged men undergoing coronary angiography. The study involved 153 current smokers, 251 who quit smoking and 311 who never smoked. Serum bilirubin concentrations were divided into the following quartiles; 0.20-0.57, 0.58-0.73, 0.74-0.95 and 0.96-3.26 mg/dl. The percentage of individuals within each quartile were as follows; current smokers (42, 22, 24, 12), former smokers (22, 27, 23, 28), nonsmokers (16, 28, 27, 29). A total of 42% of the current smokers had bilirubin concentrations in the lowest quartile compared to 16% of the nonsmokers. Also, 12% of the current smokers had bilirubin concentrations in the highest quartile compared to 29% in the nonsmoking group. The Mantel-Haenszel chi-square test for association between ordered categorical variables was 30.6 (P < 0.0001). Subdividing the subjects according to maximum percent stenosis on angiography (< 10, 10-49, 50-100%) revealed a significant inverse association between smoking and bilirubin ( < 0.01) within each subset. The data shows that smoking is associated with decreased serum bilirubin concentrations. In addition, it supports the hypothesis that cigarette smoking may increase the risk of coronary artery disease by lowering antioxidant concentrations and raising oxidized lipid and lipoprotein concentrations. (C) 1998 Elsevier Science Ireland Ltd. C1 Wilford Hall USAF Med Ctr, Clin Invest Directorate, Lackland AFB, TX 78236 USA. RP Schwertner, HA (reprint author), Wilford Hall USAF Med Ctr, Clin Invest Directorate, 1255 Wilford Hall Loop, Lackland AFB, TX 78236 USA. EM schwert-ner@whmc-lafb.af.mil NR 20 TC 86 Z9 95 U1 0 U2 3 PU ELSEVIER SCI IRELAND LTD PI CLARE PA CUSTOMER RELATIONS MANAGER, BAY 15, SHANNON INDUSTRIAL ESTATE CO, CLARE, IRELAND SN 0021-9150 J9 ATHEROSCLEROSIS JI Atherosclerosis PD FEB PY 1998 VL 136 IS 2 BP 383 EP 387 DI 10.1016/S0021-9150(97)00232-3 PG 5 WC Cardiac & Cardiovascular Systems; Peripheral Vascular Disease SC Cardiovascular System & Cardiology GA ZB864 UT WOS:000072515700021 PM 9543110 ER PT J AU Knight, KK Apsey, DA Jackson, WG Dennis, RJ AF Knight, KK Apsey, DA Jackson, WG Dennis, RJ TI A comparison of stereopsis with ANVIS and F4949 night vision goggles SO AVIATION SPACE AND ENVIRONMENTAL MEDICINE LA English DT Article AB Background: This study was undertaken to see if the model of NVG affects stereoacuity. Methods: We tested 13 male and 2 female aircrew with the Aviator's Night Vision Imaging System (ANVIS) and F4949 NVGs. Visual acuity was measured using the NVC Resolution Grid and stereopsis was determined using a modified Howard-Dolman test. Results: In simulated light conditions, average stereoscopic threshold using the F4949 NVG (17.35 arc s) was not significantly better than the ANVIS NVG (18.42 are s), the mean difference being 1.07 are s (95% confidence limits, -2.85 to 4.99). Conclusions: The Howard-Dolman test proved to be effective in eliminating monocular clues, thus validating its use in testing NVC stereopsis. The distribution of visual acuities across subjects and goggle models was too narrow to evaluate the effect of visual acuity on stereoacuity in NVGs. Differences in trial means during the course of the study indicated the presence of a "learning" effect on the Howard-Dolman test. C1 USAF, Sch Aerosp Med, Brooks AFB, TX 78235 USA. Armstrong Lab, Div Clin Sci, Brooks AFB, TX 78235 USA. RP Knight, KK (reprint author), 4926 Timber Whip, San Antonio, TX 78250 USA. NR 13 TC 8 Z9 9 U1 0 U2 2 PU AEROSPACE MEDICAL ASSOC PI ALEXANDRIA PA 320 S HENRY ST, ALEXANDRIA, VA 22314-3579 USA SN 0095-6562 J9 AVIAT SPACE ENVIR MD JI Aviat. Space Environ. Med. PD FEB PY 1998 VL 69 IS 2 BP 99 EP 103 PG 5 WC Public, Environmental & Occupational Health; Medicine, General & Internal; Sport Sciences SC Public, Environmental & Occupational Health; General & Internal Medicine; Sport Sciences GA YV836 UT WOS:000071868200001 PM 9491245 ER PT J AU Tong, A Balldin, UI Hill, RC Dooley, JW AF Tong, A Balldin, UI Hill, RC Dooley, JW TI Improved anti-G protection boosts sortie generation ability SO AVIATION SPACE AND ENVIRONMENTAL MEDICINE LA English DT Article AB Background: There is a need for evaluation of new G protection equipment. Hypothesis: There is no difference between the two anti-C ensembles on affecting subjects' ability to tolerate multiple simulated aerial combat sorties. Methods: There were 15 subjects wearing the standard CSU-13B/P anti-C ensemble (STD) or COMBAT EDGE/ATAGS (CE/ ATAGS) ensemble who were exposed to 3 centrifuge-based simulated air combat sorties during a 2-h period. Each sortie consisted of four different C-profiles: 1) a gradual onset profile; 2) simulated air combat maneuver consisting of +4.5 to +7 Gz plateaus (4.5-7 SACM); 3) simulated air combat maneuver derived from actual fighter maneuvers with peaks up to +9 Gz (TACM); 4) simulated air combat maneuver consisting of 5.0 to +9.0 Gz plateaus (5-9 SACM). Each sortie was separated by a 20-min rest period. We measured heart rate, peripheral light loss (PLL), subjective effort level, subjective fatigue level, and reported recovery time. Results: There were no incidents of unintended G-induced loss of consciousness (G-LOC) with CE/ATAGS. There were four incidents of unintended G-LOC with STD. At the end of the third sortie, with CE/ ATACS, mean heart rate was lower during the 4.5-7 SACM (p < 0.001) and the TACM (p < 0.001); PLL was less during ail three rapid onset profiles (p < 0.01); subjects reported less effort during the 4.5-7 SACM (p < 0.001), the TACM and the 5-9 SACM (p < 0.01); reported fatigue was significantly lower (p < 0.001); and reported recovery times were nearly halved (p < 0.01). Conclusion: CE/ATAGS provided significantly greater C-protection than the standard anti-C ensemble. There was no G-LOC with CE/ATAGS. This greater protection should be of significant operational value in enhancing sortie generation capability by increasing fighter aircrew C-tolerance and decreasing aircrew fatigue. C1 Armstrong Lab, Crew Technol Div, Brooks AFB, TX 78235 USA. RP Tong, A (reprint author), PSC 78,Box 2596, APO, AP 96326 USA. NR 6 TC 12 Z9 13 U1 0 U2 0 PU AEROSPACE MEDICAL ASSOC PI ALEXANDRIA PA 320 S HENRY ST, ALEXANDRIA, VA 22314-3579 USA SN 0095-6562 J9 AVIAT SPACE ENVIR MD JI Aviat. Space Environ. Med. PD FEB PY 1998 VL 69 IS 2 BP 117 EP 120 PG 4 WC Public, Environmental & Occupational Health; Medicine, General & Internal; Sport Sciences SC Public, Environmental & Occupational Health; General & Internal Medicine; Sport Sciences GA YV836 UT WOS:000071868200004 PM 9491248 ER PT J AU Ivan, DJ Tredici, TJ Burroughs, JR Pasquale, A Hickman, JR Cuervo, H Gooch, J AF Ivan, DJ Tredici, TJ Burroughs, JR Pasquale, A Hickman, JR Cuervo, H Gooch, J TI Primary idiopathic optic neuritis in US Air Force aviators SO AVIATION SPACE AND ENVIRONMENTAL MEDICINE LA English DT Article ID DEVELOPING MULTIPLE-SCLEROSIS; RISK AB The records of 31 male aviators seen al the Ophthalmology Branch of the USAF Aeromedical Consultation Service (formerly the USAF School ai Aerospace Medicine) for a diagnosis of primary idiopathic optic neuritis (PION) were reviewed. Each subject received comprehensive ophthalmologic and neurologic examinations. The long-term follow-up data were collected through repeat examinations and by survey. Despite 39% of aviators being grounded due to complications of their PION or multiple sclerosis (MS), many aviators diagnosed with PION may be safely returned to flying duties. However; any aviator diagnosed with PION has a risk of recurrence or a potential to develop systemic MS and must be carefully reevaluated and followed to ensure they remain a viable asset and do not compromise flight safety or mission completion. C1 AOCO, Armstrong Lab, Div Clin Sci, Ophthalmol Branch,Aerosp Consultat Serv, Brooks AFB, TX 78235 USA. Wilford Hall USAF Med Ctr, Dept Ophthalmol, Lackland AFB, TX 78236 USA. ISOP, Lackland AFB, TX USA. SGOSE, Dept Ophthalmol, Med Grp 7, Wright Patterson AFB, OH USA. Mayo Clin, Div Prevent Med & Cardiovasc Dis, Dept Med, Rochester, MN USA. RP Ivan, DJ (reprint author), AOCO, Armstrong Lab, Div Clin Sci, Ophthalmol Branch,Aerosp Consultat Serv, 2507 Kennedy Circle, Brooks AFB, TX 78235 USA. NR 18 TC 2 Z9 2 U1 0 U2 1 PU AEROSPACE MEDICAL ASSOC PI ALEXANDRIA PA 320 S HENRY ST, ALEXANDRIA, VA 22314-3579 USA SN 0095-6562 J9 AVIAT SPACE ENVIR MD JI Aviat. Space Environ. Med. PD FEB PY 1998 VL 69 IS 2 BP 158 EP 165 PG 8 WC Public, Environmental & Occupational Health; Medicine, General & Internal; Sport Sciences SC Public, Environmental & Occupational Health; General & Internal Medicine; Sport Sciences GA YV836 UT WOS:000071868200013 PM 9491257 ER PT J AU Wilson, GF Swain, CR Ullsperger, P AF Wilson, GF Swain, CR Ullsperger, P TI ERP components elicited in response to warning stimuli: the influence of task difficulty SO BIOLOGICAL PSYCHOLOGY LA English DT Article DE adaptation-level theory; event-related potentials; memory task; P300; performance; subjective rating; task difficulty; topographical distribution ID POTENTIALS; P300; CATEGORIZATION; PROBABILITY; WORKLOAD AB A series of experiments were conducted to systematically evaluate the relative contributions of task difficulty and stimulus probability to P300 amplitudes. Scalp event-related potentials (ERPs) were recorded and the topographic distributions were evaluated during a multi-level cognitive task with an antecedent warning. In three separate studies, task difficulty (five levels), probability or expectedness (10-60%), and randomness (random or blocked presentation) were manipulated. Response accuracy, subjective ratings, and reference-free averages of the P300 components elicited by the warning stimuli were evaluated. Statistical analysis indicated that significantly larger P300s were associated with the more difficult task warnings except when memory tasks were presented in a blocked design, suggesting that neither task difficulty nor probability alone can account for variations in the P300 in a multi-level task scenario. Results are discussed with regard to adaptation-level theory. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Armstrong Lab, CFHP, Wright Patterson AFB, OH 45433 USA. Logicon Tech Serv, Dayton, OH USA. Bundesanstalt Arbeitsschutz & Arbeitsmed, Berlin, Germany. RP Wilson, GF (reprint author), Armstrong Lab, CFHP, 2255 H St, Wright Patterson AFB, OH 45433 USA. NR 34 TC 24 Z9 24 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0301-0511 J9 BIOL PSYCHOL JI Biol. Psychol. PD FEB PY 1998 VL 47 IS 2 BP 137 EP 158 DI 10.1016/S0301-0511(97)00021-5 PG 22 WC Psychology, Biological; Behavioral Sciences; Psychology; Psychology, Experimental SC Psychology; Behavioral Sciences GA ZD313 UT WOS:000072672700003 PM 9554185 ER PT J AU Brewster, AL Nelson, JP Hymel, KP Colby, DR Lucas, DR McCanne, TR Milner, JS AF Brewster, AL Nelson, JP Hymel, KP Colby, DR Lucas, DR McCanne, TR Milner, JS TI Victim, perpetrator, family, and incident characteristics of 32 infant maltreatment deaths in the United States Air Force SO CHILD ABUSE & NEGLECT LA English DT Article DE infanticide; physical child abuse; battered-child syndrome; shaken baby; colic ID FATAL CHILD-ABUSE; EPIDEMIOLOGY; MORTALITY; HOMICIDE AB Objective: The aim of the present study was to extend the previous number of variables used to describe infanticide and identify factors that might be used to prevent infanticide. Method: Using a multidisciplinary approach, victim, perpetrator, family, and incident variables in 32 cases of infanticide were identified and examined. Available investigative, birth, medical, autopsy, and Air Force Family Advocacy Program records concerning substantiated cases of infanticide due to family maltreatment occurring in the United States Air Force from 1989 through 1995 were independently reviewed for 58 criteria. Interrater reliability was 96%. Results: Victim-The mean age of the infant-victim was 4.9 months old. Although 35% of physicians' reports about the infant-victim noted colic, only 10% of the mothers and 13% of the parent-perpetrators reported their infants as being colicky. Fifty-five percent of the infant-victims had physical trauma before the fatal incident, indicating physical abuse. At death age, the infants' weights and lengths were smaller (36th and 39th percentile, respectively) in comparison to normal infants the same age. Perpetrator-The caretaker-perpetrator had a history of abuse in childhood (23%), was male (84%), the biological father of the victim (77%), and a first-time parent (54%). Family: The infant-victim families were composed of young (mother = 23.3 years old; father = 24.3 years old), married (97%) parents with one or two children (M = 1.6). Incident: The incident had the infant-victim crying (58%) and alone with the caretaker-perpetrator (86%) on the weekend (47%) at around noon in the home (71%). Conclusions: The findings indicate several factors related to infanticide. Awareness of these factors may help in the prevention of infanticide. (C) 1998 Elsevier Science Ltd. C1 USAF, Andrews Family Practice, Malcolm Grow Med Ctr, Andrews AFB, MD 20762 USA. RP Brewster, AL (reprint author), USAF, Andrews Family Practice, Malcolm Grow Med Ctr, 89th MDOS-SGOMF,1075 W Perimeter Rd, Andrews AFB, MD 20762 USA. NR 32 TC 52 Z9 52 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0145-2134 J9 CHILD ABUSE NEGLECT JI Child Abuse Negl. PD FEB PY 1998 VL 22 IS 2 BP 91 EP 101 DI 10.1016/S0145-2134(97)00132-4 PG 11 WC Family Studies; Psychology, Social; Social Work SC Family Studies; Psychology; Social Work GA YT600 UT WOS:000071623300002 PM 9504212 ER PT J AU Storrow, AB Hernandez, AV Norton, JA AF Storrow, AB Hernandez, AV Norton, JA TI Nalmefene and the urine opiate screen SO CLINICAL CHEMISTRY LA English DT Letter ID OPIOID ANTAGONIST; KINETICS; SAFETY C1 Univ Cincinnati, Med Ctr, Dept Emergency Med, Cincinnati, OH 45267 USA. Wilford Hall USAF Med Ctr, Dept Pathol, San Antonio, TX 78236 USA. Wilford Hall USAF Med Ctr, Joint Mil Med Ctr, Emergency Med Residency, San Antonio, TX 78236 USA. RP Storrow, AB (reprint author), Univ Cincinnati, Med Ctr, Dept Emergency Med, 1509 Med Sci Bldg,POB 670769,231 Bethesda Ave, Cincinnati, OH 45267 USA. EM alstorrow@aol.com NR 11 TC 2 Z9 2 U1 0 U2 1 PU AMER ASSOC CLINICAL CHEMISTRY PI WASHINGTON PA 2101 L STREET NW, SUITE 202, WASHINGTON, DC 20037-1526 USA SN 0009-9147 J9 CLIN CHEM JI Clin. Chem. PD FEB PY 1998 VL 44 IS 2 BP 346 EP 348 PG 3 WC Medical Laboratory Technology SC Medical Laboratory Technology GA YW156 UT WOS:000071904100027 PM 9474037 ER PT J AU Kolodziej, P Lee, FS Patel, A Kassab, SS Shen, KL Yang, KH Mast, JW AF Kolodziej, P Lee, FS Patel, A Kassab, SS Shen, KL Yang, KH Mast, JW TI Biomechanical evaluation of the schuhli nut SO CLINICAL ORTHOPAEDICS AND RELATED RESEARCH LA English DT Article AB The schuhli nut is a device designed to lock an AO 4.5-mm cortical screw to a 4.5-mm dynamic compression plate independent of bony contact with the plate, The nut engages the screw below the plate, elevating the plate, and locking the screw at a 90 degrees angle, thus preventing toggling, Photoelastic modeling and biomechanical testing on sheep tibias were done to determine the mechanical properties of constructs using schuhli nuts, Use of schuhli nuts was shown to decrease stress in the bone below the plate, The initial axial stiffness of a construct fixed with schuhli nuts is less than a construct with standard screws, but the rate of loss of stiffness with cyclic loading is similar, When a cortical defect is present at the near cortex and the screw engages the far cortex only, the use of a schuhli nut significantly improves the stability of the construct compared with a standard screw alone, and behaves mechanically the same as a standard construct with intact cortices, This indicates that the schuhli nut acts as a substitute for a deficient cortex, The schuhli nut can be useful in osteoporotic bone because it prevents the screw from stripping the threads in the bone as the screw is advanced, It also serves to lock the screw to help prevent the screw from backing out, The schuhli nut may be a useful tool to improve stability in the treatment of complex fractures, reconstructions, or in pathologic bone. C1 Wayne State Univ, Sch Med, Dept Orthopaed Surg, Detroit, MI USA. Wayne State Univ, Sch Med, Dept Bioengn, Detroit, MI USA. Little Rock AFB, Little Rock, AR USA. RP Mast, JW (reprint author), 4050 E 12 Mile Rd, Warren, MI 48092 USA. NR 5 TC 47 Z9 50 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 USA SN 0009-921X J9 CLIN ORTHOP RELAT R JI Clin. Orthop. Rel. Res. PD FEB PY 1998 IS 347 BP 79 EP 85 PG 7 WC Orthopedics; Surgery SC Orthopedics; Surgery GA ZA795 UT WOS:000072402600011 ER PT J AU Clayton, AS Angeloni, V AF Clayton, AS Angeloni, V TI Bullous pemphigoid in a previously irradiated site SO CUTIS LA English DT Article ID THERAPY; RADIOTHERAPY; TETRACYCLINE AB A 58-year-old woman who had previously undergone radiation therapy for breast cancer sustained bullous pemphigoid confined mainly to the radiation site. Radiation-induced bullous pemphigoid is an infrequently reported occurrence. This patient's lesions resolved within several weeks with combined oral therapy using tetracycline and niacinamide. C1 USA, Ft Sam Houston, TX 78234 USA. USAF, Ft Sam Houston, TX USA. RP Clayton, AS (reprint author), Wilford Hall USAF Med Ctr, Brooke Army Med Ctr, Dept Dermatol, San Antonio, TX 78236 USA. NR 14 TC 6 Z9 6 U1 0 U2 0 PU EXCERPTA MEDICA INC PI NEW YORK PA 245 WEST 17TH STREET, NEW YORK, NY 10011 USA SN 0011-4162 J9 CUTIS JI Cutis PD FEB PY 1998 VL 61 IS 2 BP 73 EP 76 PG 4 WC Dermatology SC Dermatology GA YZ084 UT WOS:000072218700004 PM 9515211 ER PT J AU LeVasseur, MJG Kennard, CD Finley, MEM Muse, MRK AF LeVasseur, MJG Kennard, CD Finley, MEM Muse, MRK TI Dermatologic electrosurgery in patients with implantable cardioverter-defibrillators and pacemakers SO DERMATOLOGIC SURGERY LA English DT Article ID ELECTROMAGNETIC-INTERFERENCE; CARDIAC-PACEMAKERS; UNITED-STATES; ELECTROCAUTERY; MANAGEMENT; MAGNET AB BACKGROUND. Electrosurgery is frequently employed in the treatment of skin cancer and other dermatologic conditions in the elderly. Implantable cardioverter-defibrillators (ICDs) and pacemakers are most commonly seen in this older population. Potentially hazardous electrosurgical interference exists with the function of ICDs and pacemakers in this setting. OBJECTIVE. Our goal is to review the potential hazards of electrosurgery in patients with ICDs and pacemakers and to suggest a perioperative management plan. METHODS. Review of the medical literature on electrosurgical interference with ICDs and pacemakers was accomplished in addition to a case report of ventricular tachycardia during Mohs surgery on a patient with an ICD. RESULTS. Multiple case reports and reviews from the nondermatologic literature demonstrate that a real hazard exists. CONCLUSION. Knowledge of the potential electrosurgical interference with ICDs and pacemakers is required to perform these procedures safely. A perioperative management plan is suggested. (C) 1998 by the American Society for Dermatologic Surgery, Inc. C1 Wilford Hall USAF Med Ctr, Dept Dermatol, San Antonio, TX 78236 USA. Dept Dermatol Surg, San Antonio, TX 78236 USA. Dept Cardiol, San Antonio, TX 78236 USA. RP LeVasseur, MJG (reprint author), 605 Vandenberg Dr, Biloxi, MS 39531 USA. NR 63 TC 10 Z9 11 U1 0 U2 0 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 1076-0512 J9 DERMATOL SURG JI Dermatol. Surg. PD FEB PY 1998 VL 24 IS 2 BP 233 EP 240 PG 8 WC Dermatology; Surgery SC Dermatology; Surgery GA YX913 UT WOS:000072093300009 ER PT J AU Voevodin, AA Zabinski, JS AF Voevodin, AA Zabinski, JS TI Superhard, functionally gradient, nanolayered and nanocomposite diamond-like carbon coatings for wear protection SO DIAMOND AND RELATED MATERIALS LA English DT Article; Proceedings Paper CT 8th European Conference on Diamond, Diamond-like and Related Materials/4th International Conference on the Applications of Diamond Films and Related Materials CY AUG 03-08, 1997 CL EDINBURGH, SCOTLAND SP ASTeX, De Beers Ind Diamond Div, Elsevier Sci Ltd, Renishaw Plc DE diamond-like carbon; wear; friction; multi-layer; composite ID PULSED-LASER DEPOSITION; FILMS AB Recent progress in the development of advanced carbon-based tribological coatings is reviewed. Pulsed laser deposition (PLD) was used to produce superhard (60-70 GPa) self-lubricating diamond-like carbon (DLC) with low friction and low wear rate. Attention was given to the improvement of coating toughness. A hybrid of magnetron sputtering and PLD was used to deposit coatings with architectures designed to withstand 1-10 GPa contact stress. This included: (1) composite coatings combining hydrogen-free and hydrogenated DLC; (2) functionally gradient metal-ceramic-DLC and nanolayered coatings with crystalline metal and carbide interlayers (about 10 nm thick) between DLC layers (about 60 nm thick); and (3) nanocrystalline-amorphous composite coatings with 10-50 nm diameter carbide particles encapsulated in a DLC matrix. The research led to the fabrication of thin (2-3 mu m) DLC-based coatings for steel substrates, which could maintain friction coefficients of about 0.1 for several million cycles of unlubricated sliding at contact pressures above 1 GPa. Their scratch resistance exeeded that of conventional ceramic (TiN, TiC) coatings. (C) 1998 Elsevier Science S.A. C1 USAF, Wright Lab, Mat Directorate, Wright Patterson AFB, OH 45433 USA. RP Voevodin, AA (reprint author), USAF, Wright Lab, Mat Directorate, Wright Patterson AFB, OH 45433 USA. EM voevodaa@ml.wpafb.af.mil RI Voevodin, Andrey/I-6684-2013 NR 12 TC 124 Z9 130 U1 4 U2 46 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-9635 EI 1879-0062 J9 DIAM RELAT MATER JI Diam. Relat. Mat. PD FEB PY 1998 VL 7 IS 2-5 BP 463 EP 467 DI 10.1016/S0925-9635(97)00214-8 PG 5 WC Materials Science, Multidisciplinary SC Materials Science GA ZB444 UT WOS:000072472600068 ER PT J AU Lipscomb, JC Confer, PD Miller, MR Stamm, SC Snawder, JE Bandiera, SM AF Lipscomb, JC Confer, PD Miller, MR Stamm, SC Snawder, JE Bandiera, SM TI Metabolism of trichloroethylene and chloral hydrate by the Japanese medaka (Oryzias latipes) in vitro SO ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY LA English DT Article DE medaka; trichloroethylene; metabolism; microsomes; cytochrome P450 ID RAT-LIVER; INDUCTION; NITROSODIETHYLAMINE; CYTOCHROME-P-450; DEALKYLATION; ETHANOL; ACIDS; MICE AB Trichloroethylene (TRI), a common groundwater contaminant, is readily metabolited by mammals to produce chloral hydrate (CH), trichloroacetic acid (TCA), and trichloroethanol (TCOH). Cytochrome P450 (CYP) and other enzymes are responsible for formation of these metabolites, which are implicated in TRI's toxicity and carcinogenicity. To establish the validity of the Japanese medaka (Oryzias latipes) as an alternate test species for TRI, we examined the metabolism of TRI and CH, as well as CYP expression, in medaka liver preparations. Trichloroethylene was incubated with medaka microsomal protein, and metabolites were extracted and analyzed using gas chromatography. Microsome-mediated metabolism of TRI was observed, and a K-m value for TRI oxidation of 540 mu M and a V-max value of 213 pmol/min.mg(-1) protein were obtained. Conversion of TRI to CH, TCA, and TCOH was found with medaka hepatic subcellular fractions. In addition, a sex difference in hepatic microsomal TRI metabolism, specific CYP content, and ethoxyresorufin O-deethylase activity was noted. The lower specific activity of preparations from the livers of female medaka is compensated for by increased total protein in the larger liver mass of the female. Immunochemical analysis showed that CYP1A was readily detectable in medaka liver, but CYP2E1 was present at very low levels. These data suggest that TRI metabolism in medaka liver preparations mimics that observed in mammalian systems and supports their use as an alternative test species in the evaluation of the toxicity of TRI. C1 USAF, Armstrong Lab, Div Toxicol, Wright Patterson AFB, OH 45433 USA. GEO Ctr Inc, Wright Patterson AFB, OH 45433 USA. W Virginia Univ, Dept Biochem, Morgantown, WV 26506 USA. NIOSH, Taft Lab, Ctr Dis Control & Prevent, Cincinnati, OH 45226 USA. Univ British Columbia, Fac Pharmaceut Sci, Vancouver, BC V6T 1Z3, Canada. RP Lipscomb, JC (reprint author), USAF, Armstrong Lab, Div Toxicol, Wright Patterson AFB, OH 45433 USA. EM jlipscomb@al.wpafb.mil NR 40 TC 8 Z9 8 U1 0 U2 2 PU SETAC PRESS PI PENSACOLA PA 1010 NORTH 12TH AVE, PENSACOLA, FL 32501-3370 USA SN 0730-7268 J9 ENVIRON TOXICOL CHEM JI Environ. Toxicol. Chem. PD FEB PY 1998 VL 17 IS 2 BP 325 EP 332 DI 10.1897/1551-5028(1998)017<0325:MOTACH>2.3.CO;2 PG 8 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA YU184 UT WOS:000071690700025 ER PT J AU Rodriguez, P Kennedy, EJ Keskinen, MJ Siefring, CL Basu, S McCarrick, M Preston, J Engebretson, M Kaiser, ML Desch, MD Goetz, K Bougeret, JL Manning, R AF Rodriguez, P Kennedy, EJ Keskinen, MJ Siefring, CL Basu, S McCarrick, M Preston, J Engebretson, M Kaiser, ML Desch, MD Goetz, K Bougeret, JL Manning, R TI The WIND-HAARP experiment: Initial results of high power radiowave interactions with space plasmas SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID AURORAL MAGNETOSPHERE; IRREGULARITIES AB Results from the first science experiment with the new HF Active Auroral Research Program (HAARP) in Alaska are reported. The objective was to study the effects of space plasmas on high power radiowave transmission to high altitudes in the magnetosphere. Reception was done by the NASA/WIND satellite. The data suggest that structured space plasmas along the propagation path impose a power law spectrum of fluctuations on the transmitted waves, resembling scintillations. Because the transmitted waves are near ionospheric plasma frequencies, other types of wave-plasma interactions may occur. Such measurements can provide a new diagnostic tool. C1 USN, Res Lab, Washington, DC 20375 USA. USAF, Res Lab, Hanscom AFB, MA 01731 USA. Adv Power Technol Inc, Washington, DC 20037 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20071 USA. Univ Minnesota, Sch Phys & Astron, Minneapolis, MN 55455 USA. Observ Paris, DESPA, F-92195 Meudon, France. RP Rodriguez, P (reprint author), USN, Res Lab, Code 5550, Washington, DC 20375 USA. NR 11 TC 22 Z9 23 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD FEB 1 PY 1998 VL 25 IS 3 BP 257 EP 260 DI 10.1029/98GL00037 PG 4 WC Geosciences, Multidisciplinary SC Geology GA YV640 UT WOS:000071848000009 ER PT J AU Pachter, M Miller, RB AF Pachter, M Miller, RB TI Manual flight control with saturating actuators SO IEEE CONTROL SYSTEMS MAGAZINE LA English DT Article ID CONTROL CONSTRAINTS; LINEAR-SYSTEMS; STATE C1 USAF, Inst Technol, Wright Patterson AFB, OH 45433 USA. USAF, Informat Warfare Ctr, Kelly AFB, TX USA. RP Pachter, M (reprint author), USAF, Inst Technol, Wright Patterson AFB, OH 45433 USA. NR 27 TC 8 Z9 10 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 1066-033X J9 IEEE CONTR SYST MAG JI IEEE Control Syst. Mag. PD FEB PY 1998 VL 18 IS 1 BP 10 EP + DI 10.1109/37.648622 PG 9 WC Automation & Control Systems SC Automation & Control Systems GA YY820 UT WOS:000072188800003 ER PT J AU Wu, YF Keller, BP Fini, P Keller, S Jenkins, TJ Kehias, LT Denbaars, SP Mishra, UK AF Wu, YF Keller, BP Fini, P Keller, S Jenkins, TJ Kehias, LT Denbaars, SP Mishra, UK TI High Al-content AlGaN/GaN MODFET's for ultrahigh performance SO IEEE ELECTRON DEVICE LETTERS LA English DT Article ID POWER AB The use of an AIGaN layer with high Al mole-fraction is proposed to increase the equivalent figures of merit of the AIGaN/GaN MODFET structure, It is shown that the room temperature mobility has little degradation with increasing Al mole-fraction up to 50%. 0.7-mu m gatelength Al0.5Ga0.5N/GaN MODFET's by optical lithography exhibit a current density of 1 A/mm and three-terminal breakdown voltages up to 200 V, These devices on sapphire substrates without thermal management also show CW power densities of 2.84 and 2.57 W/mm at 8 and 10 GHz, respectively, representing a marked performance improvement for GaN-based FET's. C1 Univ Calif Santa Barbara, Dept Elect & Comp Engn, Santa Barbara, CA 93106 USA. Wright State Univ, Res Ctr, Dayton, OH 45435 USA. USAF, Wright Lab, Electron Device Div, Wright Patterson AFB, OH 45433 USA. RP Wu, YF (reprint author), Univ Calif Santa Barbara, Dept Elect & Comp Engn, Santa Barbara, CA 93106 USA. NR 9 TC 219 Z9 231 U1 0 U2 12 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0741-3106 J9 IEEE ELECTR DEVICE L JI IEEE Electron Device Lett. PD FEB PY 1998 VL 19 IS 2 BP 50 EP 53 DI 10.1109/55.658600 PG 4 WC Engineering, Electrical & Electronic SC Engineering GA YT634 UT WOS:000071626700005 ER PT J AU Jaspan, MA Mozdy, EJ Pollock, CR Hayduk, MJ Krol, MF AF Jaspan, MA Mozdy, EJ Pollock, CR Hayduk, MJ Krol, MF TI Saturable Bragg reflector mode-locked NaCl : OH- color center laser SO IEICE TRANSACTIONS ON ELECTRONICS LA English DT Letter DE modelocked laser; femtosecond laser; saturable absorber; quantum well ID SOLITON LASER; ABSORBER; GENERATION; REGION AB We extend the use of a saturable Bragg reflector to modelock a NaCl:OH- color center laser, producing pulses adjustable from 200 fs to 2 ps, and tunable from 1.499 mu m to 1.535 mu m, with the minimum pulsewidth near 1.51 mu m. The laser is self-starting, requires no dedicated dispersion compensating optics, and maintains a highly stable, nearly transform limited output pulse train with up to 150 mW average output power. C1 Cornell Univ, Sch Elect Engn, Ithaca, NY 14853 USA. USAF, Rome Lab, Photon Ctr, Rome, NY 13441 USA. RP Jaspan, MA (reprint author), Cornell Univ, Sch Elect Engn, Phillips Hall, Ithaca, NY 14853 USA. EM cpollock@ee.cornell.edu NR 15 TC 1 Z9 1 U1 0 U2 0 PU IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG PI TOKYO PA KIKAI-SHINKO-KAIKAN BLDG, 3-5-8, SHIBA-KOEN, MINATO-KU, TOKYO, 105-0011, JAPAN SN 0916-8524 EI 1745-1353 J9 IEICE T ELECTRON JI IEICE Trans. Electron. PD FEB PY 1998 VL E81C IS 2 BP 125 EP 128 PG 4 WC Engineering, Electrical & Electronic SC Engineering GA ZA033 UT WOS:000072321600006 ER PT J AU Franza, RM Gaimon, C AF Franza, RM Gaimon, C TI Flexibility and pricing decisions for high-volume products with short life cycles SO INTERNATIONAL JOURNAL OF FLEXIBLE MANUFACTURING SYSTEMS LA English DT Article DE changeover flexibility; facilities planning; market entry time ID MANUFACTURING FLEXIBILITY; PIONEERING BRANDS; TECHNOLOGY; ACQUISITION; DIFFUSION; ADOPTION; MARKET; INVESTMENT; AUTOMATION; ADVANTAGES AB We examine the competitive implications of a firm's ability to change over its facility for the manufacture of successive generations of high-volume products with short life cycles. This ability is known as changeover flexibility. The model introduced extends the existing literature in several directions. First, the model offers explicit treatment of the critical relationships between market entry time, changeover flexibility, product life cycles, and profit. Second, the model explicitly considers the effect of early market entry on the accumulation of manufacturing experience (learning), which reduces the unit production cost. Third, the product's optimal selling price is determined and its relation to the firm's changeover flexibility is examined. Last, facility flexibility is permitted to vary over a continuum. Therefore, we are able to capture decision making concerning the optimal degree of changeover flexibility. Both analytic and numerical results are reported, demonstrating the link between the operations and marketing domains in the context of a firm's optimal entrance and exit strategies. Among the key findings are (1) a firm more capable of reducing operating costs through learning over short life cycles optimally invests in more changeover flexibility, charges higher prices, and obtains greater profit; and (2) as the cost of flexible technologies decrease, a firm optimally increases its investment in changeover flexibility, enters markets earlier, and charges higher average prices over the product's life cycle. C1 US Air Force, Inst Technol, Sch Logist & Acquisit Management, Fairborn, OH 45324 USA. Georgia Inst Technol, DuPree Sch Management, Atlanta, GA 30332 USA. RP Franza, RM (reprint author), US Air Force, Inst Technol, Sch Logist & Acquisit Management, Fairborn, OH 45324 USA. NR 69 TC 13 Z9 13 U1 1 U2 5 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0920-6299 J9 INT J FLEX MANUF SYS JI Int. J. Flexible Manuf. Syst. PD FEB PY 1998 VL 10 IS 1 BP 43 EP 71 DI 10.1023/A:1007917617513 PG 29 WC Engineering, Manufacturing; Operations Research & Management Science SC Engineering; Operations Research & Management Science GA ZL870 UT WOS:000073481800003 ER PT J AU Turek, RS Roper, RG Brosnahan, JW AF Turek, RS Roper, RG Brosnahan, JW TI Further direct comparisons of incoherent scatter and medium frequency radar winds from AIDA '89 SO JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS LA English DT Article ID IMAGING DOPPLER INTERFEROMETER; SPACED ANTENNA; ARECIBO AB Mesopause level winds measured over Arecibo (18 degrees N, 67 degrees W) for the interval 1200-1416' h 10 April 1989 by the incoherent scatter (ISR) and the MAPSTAR MF radars during AIDA '89 are compared. Imaging Doppler interferometry (IDI), full correlation and three dimensional interferometry analyses have been applied to the MAPSTAR radar data. To determine the measure of agreement at time scales less than the two hour integration intervals previously employed for published AIDA data, the overall interval was split into four 34 min segments, and each analyzed individually. The agreement at the shorter timescales was found to be as good as that for the 2 h interval with, as has been noted previously, the zonal component agreement being better than that for the meridional. The IDI and Full Correlation Analysis (FCA) apparent velocities are in better agreement with the ISR winds than is the FCA true velocity. Sky maps of the distribution of IDI measured scattering point velocities are what one would expect if these represent actual line of sight wind velocities. We have looked at scattering point distributions, and find no evidence in our data for the scattering point alignment predicted by the volume scattering hypothesis. (C) 1997 Elsevier Science Ltd. All rights reserved. C1 55th Space Weather Squadron, Falcon AFB, CO USA. Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA. LaSalle Res Corp, La Salle, CO USA. RP Turek, RS (reprint author), 55th Space Weather Squadron, Falcon AFB, CO USA. NR 16 TC 12 Z9 12 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1364-6826 J9 J ATMOS SOL-TERR PHY JI J. Atmos. Sol.-Terr. Phys. PD FEB PY 1998 VL 60 IS 3 BP 337 EP 347 DI 10.1016/S1364-6826(97)00089-8 PG 11 WC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences SC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences GA ZJ420 UT WOS:000073213700005 ER PT J AU Fang, ZQ Look, DC Mier, MG AF Fang, ZQ Look, DC Mier, MG TI Characterization of deep centers in undoped semi-insulating GaAs substrates by normalized thermally stimulated current spectroscopy: Comparison of 100 and 150 mm wafers SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Article DE defects; semi-insulating (SI) GaAs; normalized thermally stimulated current (NTSC) spectroscopy ID SEMIINSULATING GAAS; GALLIUM-ARSENIDE; CZOCHRALSKI; TRAPS AB A well-established characterization method for investigating deep traps in semiinsulating (SI) GaAs is thermally stimulated current(TSC) spectroscopy; however, TSC is not considered to be a quantitative technique because it involves carrier mobility, lifetime, and geometric factors, which are either unknown or poorly known. In this paper, we first show how to quantify a TSC spectrum, by normalizing with infrared (hv = 1.13 eV) photocurrent, and then apply this method (called NTSC) to study the lateral uniformity of the main deep centers across the diameters of undoped SI GaAs wafers. The wafers used in the study include both the standard 100 mm sizes and the new 150 mm variations, and are grown by both the low and high pressure liquid encapsulated Czochralski techniques. The results reveal that the 150 mm wafers have a worse NTSC uniformity for the main traps and a higher degree of compensation, as compared these parameters for the 100 mm wafers. In addition, nonuniformities related to the electric field effects on both the TSC spectrum and the low temperature photocurrent are found in the 150 mm wafer grown by the low pressure technique. C1 Wright State Univ, Dept Phys, Dayton, OH 45435 USA. USAF, Avion Directorate, Wright Lab, Wright Patterson AFB, OH 45433 USA. RP Fang, ZQ (reprint author), Wright State Univ, Dept Phys, Dayton, OH 45435 USA. NR 14 TC 3 Z9 3 U1 0 U2 0 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 USA SN 0361-5235 J9 J ELECTRON MATER JI J. Electron. Mater. PD FEB PY 1998 VL 27 IS 2 BP 62 EP 68 DI 10.1007/s11664-998-0189-x PG 7 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA YW251 UT WOS:000071913600004 ER PT J AU Hinrichs, RE Walker, WA Schindler, WG AF Hinrichs, RE Walker, WA Schindler, WG TI A comparison of amounts of apically extruded debris using handpiece-driven nickel-titanium instrument systems SO JOURNAL OF ENDODONTICS LA English DT Article ID FLARE-UPS; ENDODONTICS AB One hundred single-rooted teeth were instrumented with Lightspeed, Profile .04 Taper Series 29, and NT McXIM instruments according to the recommendations of the manufacturers, and Flex-R files using the balanced force technique, Groups were comparable with respect to average curvature, canal length, and major and minor foramen size, A standard amount of irrigant was used for each tooth, Apically extruded debris and irrigant were collected and weighed, Debris was desiccated before being weighed, There were no statistically significant differences among the four groups with respect to total extruded debris, The amount of extruded debris was positively correlated with the amount of irrigant extruded, Factors such as canal length, curvature, and foramen size did not affect the amount of debris extruded. C1 Wilford Hall USAF Med Ctr, Dept Endodont, Lackland AFB, TX 78236 USA. Univ Texas, Hlth Sci Ctr, Adv Educ Program Endodont, San Antonio, TX 78284 USA. RP Walker, WA (reprint author), Univ Texas, Hlth Sci Ctr, Adv Educ Program Endodont, 7703 Floyd Curl Dr, San Antonio, TX 78284 USA. NR 15 TC 16 Z9 19 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 USA SN 0099-2399 J9 J ENDODONT JI J. Endod. PD FEB PY 1998 VL 24 IS 2 BP 102 EP 106 DI 10.1016/S0099-2399(98)80086-1 PG 5 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA YU777 UT WOS:000071753200006 PM 9641140 ER PT J AU Pratt, DM Brown, JR Hallinan, KP AF Pratt, DM Brown, JR Hallinan, KP TI Thermocapillary effects on the stability of a heated, curved meniscus SO JOURNAL OF HEAT TRANSFER-TRANSACTIONS OF THE ASME LA English DT Article DE heat pipes and thermosyphons; porous media; thermocapillary flows ID LIQUID-FILMS; RUPTURE AB An investigation of thermocapillary effects on heated menisci formed by volatile liquids in capillary pumped heat transfer devices has been conducted. This research ,vas motivated by the importance of the evaporation process from porous or grooved media integral to the operation of capillary pumped heat transport devices such as heat pipes and capillary pumped loops. From analysis, a criteria tvas established which predicts the thermal conditions at which the destablizing influences of thermocapillary stresses near the contact line of a heated and evaporating meniscus cause the meniscus to become unstable. Experimentally, two different idealized models of capillary pumped phase change loops were investigated to assess the suitability of the predictions. Correspondence between theory and experiment was observed. Given the observed dry-our of the evaporator at higher heat inputs after the meniscus becomes unstable, the importance of predicting the conditions at the instability onset is made clear. C1 USAF, Res Lab, VAVE, Wright Patterson AFB, OH 45433 USA. USAF, Res Lab, PR, Wright Patterson AFB, OH 45433 USA. Univ Dayton, Dept Aerosp & Mech Engn, Dayton, OH 45409 USA. RP Pratt, DM (reprint author), USAF, Res Lab, VAVE, 2130 8th St,Suite 1, Wright Patterson AFB, OH 45433 USA. NR 30 TC 35 Z9 37 U1 0 U2 6 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0022-1481 J9 J HEAT TRANS-T ASME JI J. Heat Transf.-Trans. ASME PD FEB PY 1998 VL 120 IS 1 BP 220 EP 226 DI 10.1115/1.2830045 PG 7 WC Thermodynamics; Engineering, Mechanical SC Thermodynamics; Engineering GA ZB974 UT WOS:000072527000026 ER PT J AU Wallace, W Beshear, S Williams, D Hospadar, S Owens, M AF Wallace, W Beshear, S Williams, D Hospadar, S Owens, M TI Perchlorate reduction by a mixed culture in an up-flow anaerobic fixed bed reactor SO JOURNAL OF INDUSTRIAL MICROBIOLOGY & BIOTECHNOLOGY LA English DT Article DE up-flow anaerobic fixed bed reactor; Wolinella succinogenes HAP-1; ammonium perchlorate; biofilm; suspected endocrine disruptor ID TERMINAL ELECTRON-ACCEPTOR; SUCCINOGENES; BACTERIUM AB Wolinella succinogenes HAP-1 is a Gram-negative microaerophile which reduces perchlorate to chloride by the proposed pathway ClO4 to ClO3 to ClO2 to C + O-2, a cost-effective perchlorate treatment process has been established using a consortium of facultative anaerobic organisms and W, succinogenes HAP-1. The mixed anaerobic bacterial culture containing W. succinogenes HAP-1 was examined for the ability to form a biofilm capable of perchlorate reduction. An up-flow anaerobic fixed bed reactor (UAFBR) was packed with diatomaceous earth pellets and operated at residence times of 1.17 and 0.46 h to insure a viable biofilm had attached to the diatomaceous earth pellets, Reduction rates of perchlorate to chloride in the UAFBR could be maintained at 1 g of perchlorate reduced h(-1) L-1, Studies with the same bacterial consortium in continuously stirred tank reactors (CSTR) generally reduced 0.5-0.7 g of perchlorate h(-1), Viable cell counts were performed periodically on the diatomaceous earth pellets and demonstrated that the W. succinogenes HAP-1 population was maintained at 28-47% of the total microbial population. Scanning electron micrographs demonstrated that the external and internal surfaces of the diatomaceous pellets were densely colonized with microbial cells of multiple cell types, This is the first report of an anaerobic mixed culture farming a biofilm capable of perchlorate reduction. C1 Appl Res Associates Inc, Gulf Coast Div, Tyndall AFB, FL 32403 USA. USAF Acad, Colorado Springs, CO 80840 USA. RP Wallace, W (reprint author), Appl Res Associates Inc, Gulf Coast Div, POB 40128,Missippi Rd, Tyndall AFB, FL 32403 USA. NR 25 TC 69 Z9 71 U1 2 U2 9 PU STOCKTON PRESS PI BASINGSTOKE PA HOUNDMILLS, BASINGSTOKE RG21 6XS, HAMPSHIRE, ENGLAND SN 1367-5435 J9 J IND MICROBIOL BIOT JI J. Ind. Microbiol. Biotechnol. PD FEB PY 1998 VL 20 IS 2 BP 126 EP 131 DI 10.1038/sj.jim.2900494 PG 6 WC Biotechnology & Applied Microbiology SC Biotechnology & Applied Microbiology GA ZJ940 UT WOS:000073269000010 ER PT J AU Dubinskii, MA Schepler, KL Semashko, VV Abdulsabirov, RY Korableva, SL Naumov, AK AF Dubinskii, MA Schepler, KL Semashko, VV Abdulsabirov, RY Korableva, SL Naumov, AK TI Spectroscopic analogy approach in selective search for new Ce3+-activated all-solid-state tunable ultraviolet laser materials SO JOURNAL OF MODERN OPTICS LA English DT Letter ID PERFORMANCE; CRYSTALS AB Recent progress made with Ce3+-activated materials offers numerous advantages with respect to other traditional sources of tunable ultraviolet (UV) radiation; so there is a strong incentive for further aimed searches for new Ce3+-activated materials capable of lasing with wider continuous UV tunability using all-solid-state direct UV pumping. Here we report the spectroscopic analogy approach for further aimed searches derived from the analysis of known laser materials. We also report the results of our test investigation, based on the suggested approach, where Ce3+-activated SrAlF5 is spectroscopically characterized as a promising all-solid-state tunable UV laser material which can be efficiently pumped by a quadrupled Nd laser. C1 USAF, Wright Lab, WLAAJL, Wright Patterson AFB, OH 45433 USA. Kazan State Univ, Kazan 420008, Russia. RP Dubinskii, MA (reprint author), USAF, Wright Lab, WLAAJL, Bldg 22B,2700 D St,Suite 2, Wright Patterson AFB, OH 45433 USA. RI Schepler, Kenneth/D-3730-2015; Korableva, Stella/L-7304-2015; Semashko, Vadim/P-8360-2015; Naumov, Alexander/A-1581-2014; OI Korableva, Stella/0000-0002-8469-2512; Naumov, Alexander/0000-0003-2421-7602; Schepler, Kenneth/0000-0001-9658-2305 NR 17 TC 23 Z9 23 U1 0 U2 4 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON EC4A 3DE, ENGLAND SN 0950-0340 J9 J MOD OPTIC JI J. Mod. Opt. PD FEB PY 1998 VL 45 IS 2 BP 221 EP 226 DI 10.1080/09500349808231683 PG 6 WC Optics SC Optics GA YT710 UT WOS:000071635300001 ER PT J AU Brown, GD Mealey, BL Nummikoski, PV Bifano, SL Waldrop, TC AF Brown, GD Mealey, BL Nummikoski, PV Bifano, SL Waldrop, TC TI Hydroxyapatite cement implant for regeneration of periodontal osseous defects in humans SO JOURNAL OF PERIODONTOLOGY LA English DT Article DE bone regeneration; calcium phosphates; dental cements; periodontal diseases/therapy ID POROUS HYDROXYLAPATITE IMPLANTS; BONE; RECONSTRUCTION; PLAQUE; SIZE AB A NEWLY DEVELOPED CALCIUM PHOSPHATE cement used to promote bone regeneration in craniofacial defects was examined to determine its potential for treatment of periodontal osseous defects. Sixteen patients with moderate to severe periodontal disease and 2 bilaterally similar vertical bony defects received initial therapy including scaling and root planing followed by treatment with either calcium phosphate cement, flap curettage (F/C) or debridement plus demineralized freeze-dried bone allograft (DFDBA). Standardized radiographs were exposed at baseline and 12 months postsurgery for computer assisted densitometric image analysis (CADIA). The extent of the bony defect was determined during initial and 12 month re-entry surgery. Within 6 months of implant placement, 11 of 16 patients treated with calcium phosphate cement exfoliated all or most of the implant through the gingival sulcus. At all 16 test sites, a narrow radiolucent gap formed by 1 month postsurgery at the initially tight visual interface between the radiopaque calcium phosphate cement and the walls of the bony defect. Mean probing depth reduction and clinical attachment gain at sites treated with calcium phosphate cement were 1.6 mm and 1.3 mm, respectively at 1 year. Minimal bony defect fill was accompanied by mean crestal resorption of 1.4 mm. Alveolar crestal resorption at sites with calcium phosphate cement was statistically significant (P = 0.001). These findings contrasted with the more favorable outcomes for controls treated with DFDBA or F/C. DFDBA sites exhibited probing depth reduction of 3.1 mm, clinical attachment gain of 2.9 mm, and defect fill of 2.4 mm. Respective clinical changes at F/C sites were 2.4 mm, 1.4 mm, and 1.1 mm. CADIA revealed clinically significant trends between the three treatment modalities at various areas-of-interest, Based on the findings of this study, there is no rationale available to support the use of hydroxyapatite cement implant in its current formulation for the treatment of vertical intrabony periodontal defects. C1 Dept Periodont, Davis Monthan AFB, AZ USA. Dept Periodont, Eglin AFB, FL USA. Univ Texas, Hlth Sci Ctr, Dept Dent Diagnost Sci, San Antonio, TX USA. Stat One, Diamond Head, MS USA. Virginia Commonwealth Univ, Med Coll Virginia, Dept Periodont, Richmond, VA 23298 USA. Wilford Hall USAF Med Ctr, Dept Periodont, Lackland AFB, TX 78236 USA. RP Brown, GD (reprint author), 355 Dent Squadron ACC,4175 S Alamo, Davis Monthan AFB, AZ 85707 USA. NR 37 TC 53 Z9 53 U1 0 U2 2 PU AMER ACAD PERIODONTOLOGY PI CHICAGO PA 737 NORTH MICHIGAN AVENUE, SUITE 800, CHICAGO, IL 60611-2690 USA SN 0022-3492 J9 J PERIODONTOL JI J. Periodont. PD FEB PY 1998 VL 69 IS 2 BP 146 EP 157 PG 12 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA ZA993 UT WOS:000072423700006 PM 9526913 ER PT J AU Alloway, JA Older, SA Battafarano, DF Carpenter, MT AF Alloway, JA Older, SA Battafarano, DF Carpenter, MT TI Persian Gulf War myalgia syndrome SO JOURNAL OF RHEUMATOLOGY LA English DT Letter ID CREATINE-KINASE LEVELS C1 Wilford Hall USAF Med Ctr, San Antonio, TX 78236 USA. Brooke Army Med Ctr, San Antonio, TX USA. Keesler AFB Med Ctr, Biloxi, MS USA. RP Alloway, JA (reprint author), Wilford Hall USAF Med Ctr, San Antonio, TX 78236 USA. NR 10 TC 2 Z9 2 U1 0 U2 2 PU J RHEUMATOL PUBL CO PI TORONTO PA 920 YONGE ST, SUITE 115, TORONTO, ONTARIO M4W 3C7, CANADA SN 0315-162X J9 J RHEUMATOL JI J. Rheumatol. PD FEB PY 1998 VL 25 IS 2 BP 388 EP 389 PG 2 WC Rheumatology SC Rheumatology GA YU558 UT WOS:000071729900039 PM 9489841 ER PT J AU Dominguez, CO Scherer, RF AF Dominguez, CO Scherer, RF TI Dimensionality of the Job-Related Tension Index: Factor stability between two samples of women in the US public sector SO JOURNAL OF SOCIAL PSYCHOLOGY LA English DT Article ID STRESS C1 Wright State Univ, Coll Business & Adm, Dayton, OH 45435 USA. USAF, Wright Patterson AFB, OH 45433 USA. RP Scherer, RF (reprint author), Wright State Univ, Coll Business & Adm, 120 Rike Hall, Dayton, OH 45435 USA. NR 12 TC 1 Z9 1 U1 0 U2 5 PU HELDREF PUBLICATIONS PI WASHINGTON PA 1319 EIGHTEENTH ST NW, WASHINGTON, DC 20036-1802 USA SN 0022-4545 J9 J SOC PSYCHOL JI J. Soc. Psychol. PD FEB PY 1998 VL 138 IS 1 BP 139 EP 142 PG 4 WC Psychology, Social SC Psychology GA ZB208 UT WOS:000072447400019 PM 9517319 ER PT J AU Hall, J Johnston, KA McPhillips, JP Barnes, SD Elston, DM AF Hall, J Johnston, KA McPhillips, JP Barnes, SD Elston, DM TI Nevoid basal cell carcinoma syndrome in a black child SO JOURNAL OF THE AMERICAN ACADEMY OF DERMATOLOGY LA English DT Article ID ODONTOGENIC KERATOCYST AB Nevoid basal cell carcinoma syndrome (NBCCS) is rare in black persons, We describe an 11-year-old black boy with NBCCS who presented with exotropia and a painful, expanding, cystic mass in the left posterior alveolar ridge, Further examination revealed odontogenic keratocysts with palmar and plantar pitting. Less than 5% of reported patients with NBCCS are black. To our knowledge, this is the first report of a black patient with NBCCS presenting with exotropia and an impacted molar displaced into the orbit by an odontogenic keratocyst. C1 Baylor Coll Med, Lackland AFB, TX USA. Wilford Hall USAF Med Ctr, Dept Dermatol, Lackland AFB, TX 78236 USA. Wilford Hall USAF Med Ctr, Dept Oral Surg, Lackland AFB, TX 78236 USA. Wilford Hall USAF Med Ctr, Dept Ophthalmol, Lackland AFB, TX 78236 USA. RP Elston, DM (reprint author), USA, 2200 Bergquist Dr,Ste 1, Lackland AFB, TX 78236 USA. NR 8 TC 7 Z9 7 U1 0 U2 0 PU MOSBY-YEAR BOOK INC PI ST LOUIS PA 11830 WESTLINE INDUSTRIAL DR, ST LOUIS, MO 63146-3318 USA SN 0190-9622 J9 J AM ACAD DERMATOL JI J. Am. Acad. Dermatol. PD FEB PY 1998 VL 38 IS 2 SU S BP 363 EP 365 DI 10.1016/S0190-9622(98)70585-7 PN 2 PG 3 WC Dermatology SC Dermatology GA YY629 UT WOS:000072167500019 PM 9486718 ER PT J AU Lee, JI Hecht, NL Mah, TI AF Lee, JI Hecht, NL Mah, TI TI In situ processing and properties of SiC/MoSi2 nanocomposites SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article AB A novel concept for ia situ processing of SiC/MoSi2 nanocomposites has been developed that combines the pyrolysis of MoSi2 particles coated with polycarbosilane and subsequent densification by hot pressing. After densification, a uniform dispersion of SiC particles is obtained in the MoSi2 matrix. The strength at both room and elevated temperature is dramatically improved by the processing protocol employed. The average room-temperature flexural strength measured for the SiC/MoSi2 nanocomposite was 760 versus 150 MPa for unreinforced MoSi2. The average 1250 degrees C flexural strength measured for the SiC/MoSi2 nanocomposite was 606 versus 77 MPa for unreinforced MoSi2. C1 Univ Dayton, Dept Mat Engn, Dayton, OH 45469 USA. USAF, Res Lab, Mat & Mfg Directorate, MLLN, Wright Patterson AFB, OH 45433 USA. RP Lee, JI (reprint author), Univ Dayton, Dept Mat Engn, Dayton, OH 45469 USA. NR 9 TC 39 Z9 43 U1 0 U2 1 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD FEB PY 1998 VL 81 IS 2 BP 421 EP 424 PG 4 WC Materials Science, Ceramics SC Materials Science GA YZ821 UT WOS:000072295100019 ER PT J AU English, J Green, G Jacobs, LO Andrews, TC AF English, J Green, G Jacobs, LO Andrews, TC TI Effect of the menstrual cycle on endothelium-dependent vasodilation of the brachial artery SO JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY LA English DT Meeting Abstract C1 Wilford Hall USAF Med Ctr, Lackland AFB, TX 78236 USA. Univ Texas, SW Med Ctr, Dallas, TX USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 0735-1097 J9 J AM COLL CARDIOL JI J. Am. Coll. Cardiol. PD FEB PY 1998 VL 31 IS 2 SU A BP 177A EP 178A DI 10.1016/S0735-1097(97)84478-6 PG 2 WC Cardiac & Cardiovascular Systems SC Cardiovascular System & Cardiology GA YW305 UT WOS:000071920600742 ER PT J AU Karpay, RI Plamondon, TJ Mills, SE Dove, SB AF Karpay, RI Plamondon, TJ Mills, SE Dove, SB TI Validation of an in-office dental unit water monitoring technique SO JOURNAL OF THE AMERICAN DENTAL ASSOCIATION LA English DT Article ID MICROBIAL-CONTAMINATION; LEGIONELLA; PREVALENCE; BIOFILM; SYSTEMS AB The authors conducted a study to determine the sensitivity, specificity and accuracy of HPC Samplers (Millipore Corp.) as compared with that of R2A agar and HPC agar when used to monitor dental unit water, or DUW, quality. Results were either a pass (200 colony-forming units per milliliter, or CFU/mL, or less) or a fail (greater than 200 CFU/mL). Of the 408 tests conducted, the results of the HPC Sampler agreed with R2A agar 377 times, for an accuracy rate of 92.6 percent. The authors recommend that clinicians consider using HPC Samplers, as they are a user-friendly, economical means of monitoring compliance of DUW quality. C1 Univ Texas, Hlth Sci Ctr, SA Dent Diagnost Sci, San Antonio, TX 78284 USA. 18 Med Grp, Kadena Air Base, Japan. 78th Dent Squadron, Robins AFB, GA USA. RP Karpay, RI (reprint author), Univ Texas, Hlth Sci Ctr, SA Dent Diagnost Sci, 7703 Floyd Curl Dr, San Antonio, TX 78284 USA. NR 29 TC 12 Z9 13 U1 0 U2 0 PU AMER DENTAL ASSN PI CHICAGO PA 211 E CHICAGO AVE, CHICAGO, IL 60611 USA SN 0002-8177 J9 J AM DENT ASSOC JI J. Am. Dent. Assoc. PD FEB PY 1998 VL 129 IS 2 BP 207 EP 211 PG 9 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA YW277 UT WOS:000071916200017 PM 9495053 ER PT J AU Hill, JG Grimwood, RE Hermesch, CB Marks, JG AF Hill, JG Grimwood, RE Hermesch, CB Marks, JG TI Prevalence of occupationally related hand dermatitis in dental workers SO JOURNAL OF THE AMERICAN DENTAL ASSOCIATION LA English DT Article ID ALLERGIC CONTACT-DERMATITIS; SURGICAL GLOVE POWDER; CARE UNIT PERSONNEL; LATEX ALLERGY; OPERATING-THEATER; SKIN SYMPTOMS; RUBBER; URTICARIA; SPECTRUM; ISSUES AB Occupationally related hand dermatitis has been attributed to frequent hand-washing, exposure to possible sensitizers and latex glove use, The authors conducted a study to determine the prevalence of occupationally related hand dermatitis in dental personnel, They found that 15 (19.2 percent) of 390 subjects self-reported they had a positive history of hand dermatitis, Further testing of 53 of these subjects indicated that only 9.4 percent reacted to the 45 allergens tested, anti 3.8 percent had an allergy to latex. C1 Wilford Hall USAF Med Ctr, Dept Gen Dent, Lackland AFB, TX 78236 USA. Wilford Hall USAF Med Ctr, Dept Dermatol, Lackland AFB, TX 78236 USA. RP Hermesch, CB (reprint author), Spangdahlem Air Base, Bitburg, Germany. NR 40 TC 26 Z9 27 U1 0 U2 1 PU AMER DENTAL ASSN PI CHICAGO PA 211 E CHICAGO AVE, CHICAGO, IL 60611 USA SN 0002-8177 J9 J AM DENT ASSOC JI J. Am. Dent. Assoc. PD FEB PY 1998 VL 129 IS 2 BP 212 EP 217 PG 6 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA YW277 UT WOS:000071916200018 PM 9495054 ER PT J AU Tyo, JS AF Tyo, JS TI Optimum linear combination strategy for an N-channel polarization-sensitive imaging or vision system SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION LA English DT Article ID SCATTERING MEDIA; COLOR-VISION; MODEL AB The optimum linear combination channels for an N-receptor polarization-sensitive imaging or vision system are found by using a principal-components analysis. The channels that are derived are optimum in the sense that their information contents are uncorrelated when considered over the ensemble of possible polarization signals. For a two-receptor system, the optimum channels are shown to be the sum and the difference of the outputs of the individual receptors. As a corollary, the optimal arrangement of the two receptors is shown to be a mosaic of identical, orthogonally aligned linear polarization analyzers. The implications of these results on the development of a representational scheme for polarization information are discussed. (C) 1998 Optical Society of America. C1 Univ Penn, Moore Sch Elect Engn, Philadelphia, PA 19104 USA. RP Tyo, JS (reprint author), USAF, Res Lab, DEHP, High Energy Sources Branch, 3550 Aberdeen SE, Kirtland AFB, NM 87117 USA. NR 24 TC 46 Z9 46 U1 0 U2 2 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0740-3232 J9 J OPT SOC AM A JI J. Opt. Soc. Am. A-Opt. Image Sci. Vis. PD FEB PY 1998 VL 15 IS 2 BP 359 EP 366 DI 10.1364/JOSAA.15.000359 PG 8 WC Optics SC Optics GA YT999 UT WOS:000071669700007 ER PT J AU Tyo, JS Pugh, EN Engheta, N AF Tyo, JS Pugh, EN Engheta, N TI Colorimetric representations for use with polarization-difference imaging of objects in scattering media SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION LA English DT Article ID COLOR-VISION AB Polarization-difference imaging (PDI) has been shown to yield an improvement in the qualitative and quantitative detectability of objects in scattering media. In this investigation, PDI and conventional, polarization-blind imaging are combined to yield a novel representational scheme generally suitable for detection of targets having a low degree of linear polarization and specifically suitable for detection and discrimination of weakly polarizing targets in scattering media. This representational scheme meets several general criteria for optimization of the presentation of low-signal image information to human observers and takes specific advantage of the properties of the opponent-color coding used by the human visual system. (C) 1998 Optical Society of America. C1 Univ Penn, Moore Sch Elect Engn, Philadelphia, PA 19104 USA. Univ Penn, Dept Psychol, Philadelphia, PA 19104 USA. Univ Penn, Inst Neurol Sci, Philadelphia, PA 19104 USA. RP Tyo, JS (reprint author), USAF, Res Lab, DEHP, High Energy Sources Branch, 3550 Aberdeen SE, Kirtland AFB, NM 87117 USA. NR 24 TC 55 Z9 55 U1 0 U2 1 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0740-3232 J9 J OPT SOC AM A JI J. Opt. Soc. Am. A-Opt. Image Sci. Vis. PD FEB PY 1998 VL 15 IS 2 BP 367 EP 374 DI 10.1364/JOSAA.15.000367 PG 8 WC Optics SC Optics GA YT999 UT WOS:000071669700008 ER PT J AU Sun, G Khurgin, JB Friedman, L Soref, RA AF Sun, G Khurgin, JB Friedman, L Soref, RA TI Tunable intersubband Raman laser in GaAs/AlGaAs multiple quantum wells SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID CASCADE LASER; SCATTERING AB A new tunable source of infrared radiation based on intersubband electron Raman scattering in semiconductor quantum wells is studied theoretically. The structure consisting of three levels in two coupled GaAs/AlGaAs quantum wells is optimized for a maximum Raman gain at zero bias. Raman gain as large as 400/cm can be achieved according to our calculations. Lasing wavelengths are tuned when an external de bias field is applied along the growth direction. An infrared tuning range of 8-12 mu m with moderate Raman gain is predicted as the electric field is varied from -40 to 40 kV/cm. (C) 1998 Optical Society of America. C1 Univ Massachusetts, Dept Phys, Boston, MA 02125 USA. Johns Hopkins Univ, Dept Elect & Comp Engn, Baltimore, MD 21218 USA. USAF, Rome Lab, Hanscom AFB, MA 01731 USA. RP Sun, G (reprint author), Univ Massachusetts, Dept Phys, Boston, MA 02125 USA. RI khurgin, Jacob/A-3278-2010 NR 14 TC 25 Z9 25 U1 0 U2 1 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0740-3224 J9 J OPT SOC AM B JI J. Opt. Soc. Am. B-Opt. Phys. PD FEB PY 1998 VL 15 IS 2 BP 648 EP 651 DI 10.1364/JOSAB.15.000648 PG 4 WC Optics SC Optics GA YX192 UT WOS:000072015600016 ER PT J AU Calhoun, S AF Calhoun, S TI Becoming human: Evolution and human uniqueness. SO LIBRARY JOURNAL LA English DT Book Review C1 USAF, Res Lab, Tyndall Div, Tech Informat Ctr, Panama City, FL 32403 USA. RP Calhoun, S (reprint author), USAF, Res Lab, Tyndall Div, Tech Informat Ctr, Panama City, FL 32403 USA. NR 1 TC 0 Z9 0 U1 1 U2 1 PU BOWKER MAGAZINE GROUP CAHNERS MAGAZINE DIVISION PI NEW YORK PA 249 W 17TH ST, NEW YORK, NY 10011 USA SN 0363-0277 J9 LIBR J JI Libr. J. PD FEB 1 PY 1998 VL 123 IS 2 BP 95 EP 95 PG 1 WC Information Science & Library Science SC Information Science & Library Science GA YU931 UT WOS:000071771000113 ER PT J AU Maddox, L Reeves, M Wood, K Roberts, K Studer, J Wetzel, J Smith, JT Whittington, K Alls, JL Parker, JE Holwitt, E Kiel, J Wright, JR AF Maddox, L Reeves, M Wood, K Roberts, K Studer, J Wetzel, J Smith, JT Whittington, K Alls, JL Parker, JE Holwitt, E Kiel, J Wright, JR TI Acoustic wave dosimetry based on diazotized luminol solutions SO MICROCHEMICAL JOURNAL LA English DT Article DE luminol; diazonium species; sonic dosimetry; chemiluminescence; sonoluminescence; sonochemiluminescence; pulsed microwave radiation ID CHEMILUMINESCENT AB High-power pulsed microwave fluences interact with aqueous solutions in a complex way. The incident energy partitions into direct heating (generally on the side facing the source) and an acoustic wave transient (the so-called microwave acoustic effect) which may dissipate thermal energy differently based on absorber geometry and acoustic wave interference. Iu a search for chemiluminescent (imaging) dosimeters suitable for distinguishing direct heating and acoustic wave phenomena, we found that dilute solutions of diazotized luminol produce a reliable 200-fold luminescence increase above the quiescent condition when 115 mi of the solution is subjected to 62 W of 20-kHz acoustic energy. The contrast ratio (irradiated to quiescent) is markedly diminished and irreproducibility is introduced if carbon dioxide is not thoroughly excluded from the dosimeter solution by bubbling with nitrogen gas before use. Dissolved carbon dioxide acts mainly to increase quiescent thermochemiluminescence. The ratio is largest if the dosimeter solution is chilled to 0 degrees C. The contrast ratio is pH dependent and maximum between pH 7 and 7.5, and sonochemiluminescence generated in this manner fades with a time constant of about 0.5 s when the irradiation is stopped. The light output from this dosimeter is well above the sonoluminescence produced in pure water under the same irradiation conditions. (C) 1998 Academic Press. C1 SE Oklahoma State Univ, Dept Phys Sci, Durant, OK 74701 USA. Armstrong Lab, Radiofrequency Radiat Div, Brooks AFB, TX 78235 USA. RP Wright, JR (reprint author), SE Oklahoma State Univ, Dept Phys Sci, Durant, OK 74701 USA. NR 10 TC 1 Z9 1 U1 1 U2 3 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0026-265X J9 MICROCHEM J JI Microchem J. PD FEB PY 1998 VL 58 IS 2 BP 209 EP 217 DI 10.1006/mchj.1997.1541 PG 9 WC Chemistry, Analytical SC Chemistry GA ZD307 UT WOS:000072672100009 ER PT J AU Medell, RJ Waisel, DB Eskuri, SA Calicott, RW AF Medell, RJ Waisel, DB Eskuri, SA Calicott, RW TI Field block for cranial surgery in World War II SO MILITARY MEDICINE LA English DT Article AB During World War II, physicians with minimal training were often thrust into the role of anesthetist. To educate these men, experts in anesthesia taught simple, conservative, and effective anesthetic techniques, such as the field block. Field blocks are the ideal "no frills" anesthetic because they are low-risk procedures that require minimal equipment. Unfortunately, many of the field blocks used during World War II are no longer taught. We present one technique that has fallen from favor, the field block for cranial surgery, both to educate about anesthesiology during World War II and to provide knowledge for the practicing military physician. The modern military anesthesiologist must be capable of anesthetizing patients under any conditions. First response care teams may find the technique of field block for cranial surgery useful in providing emergency anesthesia care. C1 USAF, PSSA, Med Wing 59, Lackland AFB, TX 78236 USA. RP Medell, RJ (reprint author), USAF, PSSA, Med Wing 59, 2200 Bergquist Dr,Suite 1, Lackland AFB, TX 78236 USA. OI Waisel, David/0000-0002-5307-4092 NR 7 TC 2 Z9 2 U1 0 U2 0 PU ASSN MILITARY SURG US PI BETHESDA PA 9320 OLD GEORGETOWN RD, BETHESDA, MD 20814 USA SN 0026-4075 J9 MIL MED JI Milit. Med. PD FEB PY 1998 VL 163 IS 2 BP 80 EP 83 PG 4 WC Medicine, General & Internal SC General & Internal Medicine GA YX190 UT WOS:000072015400009 PM 9503897 ER PT J AU Pascuzzi, TA Storrow, AB AF Pascuzzi, TA Storrow, AB TI Mass casualties from acute inhalation of chloramine gas SO MILITARY MEDICINE LA English DT Article ID CHLORINE GAS; EXPOSURE AB Mass exposure to chloramine gas has not been reported. We report two groups of 36 patients (72 total) suffering from acute inhalation of chloramine gas. Chloramine gas is produced from mixing common household cleaning agents containing sodium hypochlorite (bleach) and ammonia. The first mass casualty event occurred when 36 male soldiers mere exposed during a "cleaning party" in their barracks. Ten days later, 36 female soldiers were exposed in a similar manner and presented to our emergency department. In each event, commonly available cleaning agents - liquid bleach and ammonia - were mixed together, liberating toxic chloramine gas. Nebulized sodium bicarbonate solution has been suggested for treatment of chlorine gas inhalation, but no report of nebulized sodium bicarbonate for treatment of chloramine gas inhalation injury exists. In our series, 22 patients exposed to chloramine gas were treated with a nebulized solution of 3.75% sodium bicarbonate. This treatment made no significant statistical or clinical difference in outcome. We present the largest case series of patients presenting to an emergency department for treatment of acute inhalation of chloramine gas. C1 Wilford Hall USAF Med Ctr, Joint Mil Med Ctr Emergency Med Residency, San Antonio, TX 78236 USA. RP Storrow, AB (reprint author), Univ Cincinnati, POB 670769, Cincinnati, OH 45267 USA. EM alan.storrow@uc.edu NR 23 TC 16 Z9 16 U1 1 U2 5 PU ASSN MILITARY SURG US PI BETHESDA PA 9320 OLD GEORGETOWN RD, BETHESDA, MD 20814 USA SN 0026-4075 J9 MIL MED JI Milit. Med. PD FEB PY 1998 VL 163 IS 2 BP 102 EP 104 PG 3 WC Medicine, General & Internal SC General & Internal Medicine GA YX190 UT WOS:000072015400014 PM 9503902 ER PT J AU Hong, L Ding, Z Wood, RA AF Hong, L Ding, Z Wood, RA TI Development of multirate model and multirate interacting multiple model algorithm for multiplatform multisensor tracking SO OPTICAL ENGINEERING LA English DT Article DE sensor fusion; multiple model algorithm; multiplatform tracking; distributed system; multirate measurement; multirate model ID SYSTEMS AB A distributed multirate interacting multiple model (DMRIMM) tracking algorithm is developed. The algorithm is based on a reformulation of the interacting multiple model (IMM) filter under the assumption that each model operates at an update rate proportional to the model's assumed dynamics. A multirate model is derived based on the geometrical interpretation of a discrete wavelet transform. A wavelet transform is used to generate equivalent multirate measurements, which exhibit the additional property of lower equivalent measurement noise for low-rate data. Using this filtering approach, the MRIMM algorithm significantly outperforms a full-rate IMM filter when no maneuvers occur and moderately outperforms the IMM filter when maneuvers occur, Based on the MRIMM algorithm, a distributed version DMRIMM algorithm for multiplatform multisensor tracking is proposed. The MRIMM algorithm is first employed to perform each local/platform estimation. A global filter is then constructed to perform a fusion of MRIMM estimations. The advantage of performance improvement is demonstrated through Monte Carlo simulations. (C) 1998 Society of Photo-Optical instrumentation Engineers. C1 Wright State Univ, Dept Elect Engn, Dayton, OH 45435 USA. USAF, Wright Lab, Combat Informat Div, Fus Dev Branch, Wright Patterson AFB, OH 45433 USA. RP Hong, L (reprint author), Wright State Univ, Dept Elect Engn, Dayton, OH 45435 USA. NR 22 TC 13 Z9 16 U1 0 U2 0 PU SPIE - INTERNATIONAL SOCIETY FOR OPTICAL ENGINEERING PI BELLINGHAM PA POB 10, BELLINGHAM, WA 98227-0010 USA SN 0091-3286 J9 OPT ENG JI Opt. Eng. PD FEB PY 1998 VL 37 IS 2 BP 453 EP 467 DI 10.1117/1.601631 PG 15 WC Optics SC Optics GA YX568 UT WOS:000072053600011 ER PT J AU Schock, M Spillar, EJ AF Schock, M Spillar, EJ TI Measuring wind speeds and turbulence with a wave-front sensor SO OPTICS LETTERS LA English DT Article AB We analyze wave-front sensor (WFS) measurements taken with the 1.5-m telescope at the Starfire Optical Range in Albuquerque, N.M., of wind speeds in the turbulent atmospheric layers that cause seeing. The frozen-flow hypothesis suggests that atmospheric turbulence is located in thin horizontal layers and that turbulent features do not change over short time scales but are drawn along by the prevailing wind. Exploiting autocorrelation properties of the WFS data that result from these characteristics of atmospheric turbulence, we are able to measure the movements of individual layers. We also test the validity of the frozen-flow hypothesis. (C) 1998 Optical Society of America. OCIS codes: 010.1080, 280.0280, 010.7350, 010.1330, 010.7060. C1 Univ Wyoming, Dept Phys & Astron, Laramie, WY 82071 USA. USAF, Phillips Lab, Starfire Opt Range, Kirtland AFB, NM 87117 USA. RP Schock, M (reprint author), Univ Wyoming, Dept Phys & Astron, POB 3905,Univ Stn, Laramie, WY 82071 USA. NR 10 TC 13 Z9 14 U1 1 U2 6 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD FEB 1 PY 1998 VL 23 IS 3 BP 150 EP 152 DI 10.1364/OL.23.000150 PG 3 WC Optics SC Optics GA YU188 UT WOS:000071691100002 PM 18084442 ER PT J AU Gardner, TL Elston, DM AF Gardner, TL Elston, DM TI A foot rash with a foul odor SO PHYSICIAN AND SPORTSMEDICINE LA English DT Article ID PITTED KERATOLYSIS C1 Wilford Hall USAF Med Ctr, Dept Dermatol, Lackland AFB, TX 78236 USA. Wilford Hall USAF Med Ctr, Dermatol Serv, Lackland AFB, TX 78236 USA. RP Elston, DM (reprint author), Wilford Hall USAF Med Ctr, Dept Dermatol, Lackland AFB, TX 78236 USA. NR 11 TC 1 Z9 2 U1 0 U2 0 PU MCGRAW HILL HEALTHCARE PUBLICATIONS PI MINNEAPOLIS PA 4530 WEST 77TH ST, MINNEAPOLIS, MN 55435-5000 USA SN 0091-3847 J9 PHYSICIAN SPORTSMED JI Physician Sportsmed. PD FEB PY 1998 VL 26 IS 2 BP 104 EP + PG 3 WC Primary Health Care; Orthopedics; Sport Sciences SC General & Internal Medicine; Orthopedics; Sport Sciences GA YU802 UT WOS:000071756100016 PM 20086784 ER PT J AU Bairamov, BK Polushina, IK Rud, YV Rud, VY Schunemann, PG Ohmer, MC Fernelius, NC Irmer, G Monecke, J AF Bairamov, BK Polushina, IK Rud, YV Rud, VY Schunemann, PG Ohmer, MC Fernelius, NC Irmer, G Monecke, J TI Optoelectronic effects in p-CdGeAs2 single crystals and structures based on them SO PHYSICS OF THE SOLID STATE LA English DT Article ID CHARGE-CARRIER TRANSPORT; ANISOTROPY AB Spectra of inelastic light scattering by optical phonons in p-CdGeAs2 single crystals were obtained for the first time. The observed clear polarization dependence and the absence of any appreciable dependence of the intensity and frequency of the observed lines when the sample is swept in approximate to 300 mu m steps indicates these CdGeAs2 single crystals grown by directional crystallization from a near-stoichiometric flux, are of high quality and homogeneous. The type of symmetry of the observed phonon lines is interpreted and it is shown that the force constants in CdGeAs2 and CdSnP2 crystals differ slightly. Temperature dependences of the electrical conductivity and the Hall constant were studied in oriented homogeneous p-CdGeAs2 single crystals. It was established that the conductivity of these crystals is determined by the deep acceptor level E-A=0.175 eV and has the degree of compensation 0.5-0.6. The temperature dependence of the Hall mobility reflects the competition between impurity and lattice mechanisms of hole scattering. The photosensitivity of In/CdGeAs2 surface barrier structures reaches 20 mu A/W at T=300 K and remains at this level within the fundamental absorption of CdGeAs2. It is concluded that these structures may be used as wide-band photoconverters for natural light and as selective photoanalyzers for linearly polarized radiation. (C) 1998 American Institute of Physics. C1 Russian Acad Sci, AF Ioffe Physicotech Inst, St Petersburg 194021, Russia. Leningrad State Tech Univ, St Petersburg 195251, Russia. Lockheed Sanders Inc, Nashua, NH USA. USAF, Wright Lab, AFWL, Wright Patterson AFB, OH 45433 USA. Bergakad Freiberg, Inst Theoret Phys, D-09596 Freiberg, Germany. RP Bairamov, BK (reprint author), Russian Acad Sci, AF Ioffe Physicotech Inst, St Petersburg 194021, Russia. RI Bairamov, Bakhysh/C-1009-2014 OI Bairamov, Bakhysh/0000-0002-9782-6399 NR 15 TC 2 Z9 2 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 1063-7834 J9 PHYS SOLID STATE+ JI Phys. Solid State PD FEB PY 1998 VL 40 IS 2 BP 190 EP 194 DI 10.1134/1.1130269 PG 5 WC Physics, Condensed Matter SC Physics GA ZC004 UT WOS:000072529900009 ER PT J AU Pessa, JE Garza, PA Love, VM Zadoo, VP Garza, JR AF Pessa, JE Garza, PA Love, VM Zadoo, VP Garza, JR TI The anatomy of the labiomandibular fold SO PLASTIC AND RECONSTRUCTIVE SURGERY LA English DT Article ID NASOLABIAL FOLD; RHYTIDECTOMY; CHEEK; SMAS AB The anatomy of the labiomandibular fold was evaluated in a series of ii fresh hemifacial cadaver dissections. The techniques of methylene blue dye injection, histologic evaluation, and gross dissection all confirm that the labiomandibular fold has distinct anatomic boundaries. The superior boundary is formed by the cutaneous insertion of the depressor anguli oris muscle at the labiomandibular crease. The inferior boundary is determined by the mandibular ligament, which has been previously described. The cutaneous insertion of the depressor muscle and the mandibular ligament act as relative points of fixation. The dynamic forces of both aging and facial animation act about these two points to create the typical appearance of the labiomandibular fold. This anatomy is consistent with that seen in other areas of the face such as the nasolabial and nasojugal folds, where the dermal insertion of muscle and/or fascia defines an anatomically distinct region. Clinically, this anatomy may suggest that a subcutaneous plane of dissection during the face lift procedure may allow manipulation and reduction of the fat that was noted lateral to the dermal insertion of the depressor anguli muscle. Subcutaneous dissection also avoids lateral pull on the platysma muscle, which may tend to accentuate and distort the labiomandibular crease due to its intimate association with the overlying depressor muscle. C1 Univ Texas, Hlth Sci Ctr, Dept Plast & Reconstruct Surg, Div Plast & Reconstruct Surg, San Antonio, TX 78284 USA. Wilford Hall USAF Med Ctr, San Antonio, TX 78236 USA. RP Pessa, JE (reprint author), Univ Texas, Hlth Sci Ctr, Dept Plast & Reconstruct Surg, Div Plast & Reconstruct Surg, 7703 Floyd Curl Dr, San Antonio, TX 78284 USA. NR 17 TC 18 Z9 20 U1 0 U2 2 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 USA SN 0032-1052 J9 PLAST RECONSTR SURG JI Plast. Reconstr. Surg. PD FEB PY 1998 VL 101 IS 2 BP 482 EP 486 DI 10.1097/00006534-199802000-00037 PG 5 WC Surgery SC Surgery GA ZF104 UT WOS:000072863000037 PM 9462785 ER PT J AU Ellerbroek, BL Tyler, DW AF Ellerbroek, BL Tyler, DW TI Adaptive optics sky coverage calculations for the Gemini-North telescope SO PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC LA English DT Article ID COMPENSATION; PERFORMANCE; SYSTEMS AB Sky coverage results are presented for several natural guide star (NGS) and laser guide star (LGS) adaptive optics (AO) configurations using scenario, telescope, and AO design parameters derived from the Gemini-North 8 m telescope. "Sky coverage" is defined as that fraction of the sky over which the AO system provides a useful level of performance, in this case a high Strehl ratio in the J, H, or K band. Some of the factors considered in this study include optimization of the AO wavefront reconstruction algorithm and control bandwidth, the effect of windshake-induced tip/tilt jitter, and the conjugation of the AO system's deformable mirror (DM) and wavefront sensor (WFS) to the dominant seeing layer at the Gemini-North site. The degree of compensation of the tip/tilt guide star image by the higher order adaptive optics is also considered. LGS AO using a single beacon in the mesospheric sodium layer typically improves sky coverage by about an order of magnitude relative to NGS AO, principally because a very dim natural guide star is sufficient for tip/tilt sensing when its image is sharpened by LGS higher order compensation. The values assumed for windshake, seeing, zenith angle, and the conjugate range of the DM and WFS also have a highly significant effect upon the estimated sky coverage for both the NGS and the LGS AO systems. The first three of these factors will need to be considered by scheduling algorithms for queue-based observing. C1 USAF, Res Lab, Starfire Opt Range, Kirtland AFB, NM 87117 USA. Schafer Corp, Kirtland AFB, NM 87117 USA. RP Ellerbroek, BL (reprint author), USAF, Res Lab, Starfire Opt Range, Kirtland AFB, NM 87117 USA. EM ellerbrb@ug2.plk.af.mil; tyler@freestyle.plk.af.mil NR 24 TC 28 Z9 28 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-6280 J9 PUBL ASTRON SOC PAC JI Publ. Astron. Soc. Pac. PD FEB PY 1998 VL 110 IS 744 BP 165 EP 185 DI 10.1086/316120 PG 21 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA ZB272 UT WOS:000072454400007 ER PT J AU Wu, Y Rong, Y Ma, W LeClair, SR AF Wu, Y Rong, Y Ma, W LeClair, SR TI Automated modular fixture planning: Geometric analysis SO ROBOTICS AND COMPUTER-INTEGRATED MANUFACTURING LA English DT Article DE computer-aided fixture design; CAD/CAM; fixturing geometric analysis AB Attendant Processes such as fixture and die design are often a necessary but time-consuming and expensive component of a production cycle. Coupling such attendant processes to product design via feature-based CAD will lead to more responsive and affordable product design and redesign. In the context of on-going research in automating fixture configuration design, this paper presents a fundamental study of automated fixture planning with a focus on geometric analysis. The initial conditions for modular fixture assembly are established together with geometric relationships between fixture components and the workpiece to be analyzed. Of particular focus is the design of alternative locating points and components, together with examples of 3-D fixture designs. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 So Illinois Univ, Mfg Syst Program, Carbondale, IL 62901 USA. Univ Illinois, Dept Mech & Ind Engn, Urbana, IL 61801 USA. USAF, Wright Lab, Mat Directorate, Wright Patterson AFB, OH 45433 USA. RP Rong, Y (reprint author), So Illinois Univ, Mfg Syst Program, Carbondale, IL 62901 USA. NR 20 TC 55 Z9 61 U1 0 U2 8 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0736-5845 J9 ROBOT CIM-INT MANUF JI Robot. Comput.-Integr. Manuf. PD FEB PY 1998 VL 14 IS 1 BP 1 EP 15 DI 10.1016/S0736-5845(97)00024-0 PG 15 WC Computer Science, Interdisciplinary Applications; Engineering, Manufacturing; Robotics SC Computer Science; Engineering; Robotics GA ZQ586 UT WOS:000073882900001 ER PT J AU Wu, Y Rong, Y Ma, W LeClair, SR AF Wu, Y Rong, Y Ma, W LeClair, SR TI Automated modular fixture planning: Accuracy, clamping, and accessibility analyses SO ROBOTICS AND COMPUTER-INTEGRATED MANUFACTURING LA English DT Article DE computer-aided fixture design; CAD/CAM; fixturing accuracy; clamp planning; accessibility; fixturing stability AB Automated fixture design has become a research focus in process planning and CAD/CAM integration. An automated fixture configuration design system has been developed where when fixturing surfaces and points are specified, modular fixture components can be automatically selected to generate fixture units and placed into position with satisfying assemble conditions. A geometric analysis has been conducted to determine the fixturing surfaces and points which provide feasible geometric constraints and assembly relationships with modular fixtures. This paper presents an analysis on fixturing accuracy, clamp planning, fixturing accessibility, and clamping stability. When a fixture planning is determined, the analysis results can be applied to verify the performance of the fixture design. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 So Illinois Univ, Mfg Syst Program, Carbondale, IL 62901 USA. Univ Illinois, Dept Mech & Ind Engn, Urbana, IL 61801 USA. USAF, Wright Lab, Mat Directorate, Wright Patterson AFB, OH 45433 USA. RP Rong, Y (reprint author), So Illinois Univ, Mfg Syst Program, Carbondale, IL 62901 USA. NR 10 TC 32 Z9 37 U1 0 U2 9 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0736-5845 J9 ROBOT CIM-INT MANUF JI Robot. Comput.-Integr. Manuf. PD FEB PY 1998 VL 14 IS 1 BP 17 EP 26 DI 10.1016/S0736-5845(97)00025-2 PG 10 WC Computer Science, Interdisciplinary Applications; Engineering, Manufacturing; Robotics SC Computer Science; Engineering; Robotics GA ZQ586 UT WOS:000073882900002 ER PT J AU Schelonka, RL Infante, AJ AF Schelonka, RL Infante, AJ TI Neonatal immunology SO SEMINARS IN PERINATOLOGY LA English DT Review ID COLONY-STIMULATING FACTOR; NAIVE B-CELLS; T-CELLS; NEWBORN-INFANTS; CD40 LIGAND; CORD-BLOOD; L-SELECTIN; N-REGIONS; ACTIN POLYMERIZATION; BACTERIAL-INFECTION C1 Wilford Hall USAF Med Ctr, Dept Pediat, Div Neonatol, Lackland AFB, TX 78236 USA. Univ Texas, Hlth Sci Ctr, Dept Pediat, Div Hematol Oncol Immunol, San Antonio, TX 78284 USA. RP Infante, AJ (reprint author), Univ Texas, Hlth Sci Ctr, Dept Pediat, Div Hematol Oncol Immunol, 7703 Floyd Curl Dr, San Antonio, TX 78284 USA. NR 62 TC 95 Z9 96 U1 0 U2 0 PU W B SAUNDERS CO PI PHILADELPHIA PA INDEPENDENCE SQUARE WEST CURTIS CENTER, STE 300, PHILADELPHIA, PA 19106-3399 USA SN 0146-0005 J9 SEMIN PERINATOL JI Semin. Perinatol. PD FEB PY 1998 VL 22 IS 1 BP 2 EP 14 DI 10.1016/S0146-0005(98)80003-7 PG 13 WC Obstetrics & Gynecology; Pediatrics SC Obstetrics & Gynecology; Pediatrics GA YZ652 UT WOS:000072276500002 PM 9523395 ER PT J AU Look, DC Reynolds, DC Sizelove, JR Jones, RL Litton, CW Cantwell, G Harsch, WC AF Look, DC Reynolds, DC Sizelove, JR Jones, RL Litton, CW Cantwell, G Harsch, WC TI Electrical properties of bulk ZnO SO SOLID STATE COMMUNICATIONS LA English DT Article DE semiconductors; crystal growth; point defects; electronic transport; luminescence AB Large-diameter (2-inch), n-type ZnO boules grown by a new vapor-phase transport method were investigated by the temperature-dependent Hall-effect technique. The 300-K Hall carrier concentration and mobility were about 6 x 10(16) cm(-3) and 205 cm(2) V-1 s(-1) respectively, and the peak mobility (at 50K) was about 2000 cm(2) V-1 s(-1), comparable to the highest values reported in the East for ZnO. The dominant donor had a concentration of about 1 x 10(17) cm(-3) and an energy of about 60 meV, close to the expected hydrogenic value, whereas the total acceptor concentration was much lower, about 2 x 10(15) cm(-3). Photoluminescence measurements confirm the high quality of the material. (C) 1998 Elsevier Science Ltd. C1 Wright State Univ, Res Ctr, Dayton, OH 45435 USA. USAF, Wright Lab, Avion Directorate, AADP, Wright Patterson AFB, OH 45433 USA. Eagle Picher Ind Inc, Miami, OK 74354 USA. RP Look, DC (reprint author), Wright State Univ, Res Ctr, Dayton, OH 45435 USA. NR 13 TC 597 Z9 641 U1 13 U2 146 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-1098 J9 SOLID STATE COMMUN JI Solid State Commun. PD FEB PY 1998 VL 105 IS 6 BP 399 EP 401 DI 10.1016/S0038-1098(97)10145-4 PG 3 WC Physics, Condensed Matter SC Physics GA YU443 UT WOS:000071717800009 ER PT J AU Reever, MM Lyon, DS Mokhtarian, PL Ahmed, F AF Reever, MM Lyon, DS Mokhtarian, PL Ahmed, F TI Early postpartum discharge versus traditional length of stay: Patient preferences SO SOUTHERN MEDICAL JOURNAL LA English DT Article ID HOSPITAL DISCHARGE; PERINATAL-CARE; CHILDBIRTH; SATISFACTION; EXPERIENCES; DELIVERY; MOTHERS; INFANTS; BIRTH AB Background. Despite a vast body of literature on postpartum safety issues, little has been written about patients' preferences for hospitalized versus home-based support and reasons for those choices. Methods. A questionnaire was offered to obstetric patients at a prenatal class. Data were analyzed using chi-square analysis and legit modeling, searching for factors accounting for the patient's choice of discharge plan. Results Neither demographic nor style-of-care variables affected patient choice significantly. Personal issues like comfort with child care were highly correlated, both individually and as a group, with choice of length of stay, Less than 25% of the group studied expressed a desire for early discharge. Conclusions. Women with a high internal locus of control and/or distrust of the medical system expressed a desire for early postpartum discharge. Few women in our study exhibited those qualities; over 75% of those who had a preference wanted a longer period of hospitalization. Although our sample has both negative and positive skews in terms of other available social supports, it is a well-educated and economically well-supported group. We conclude that many women do not believe they would be ready to leave the hospital at less than 24 hours postpartum. C1 89th Med Grp, Andrews AFB, MD USA. RP Lyon, DS (reprint author), Univ Florida, Hlth Sci Ctr, Dept Obstet Gynecol, 653-1 W 8th St, Jacksonville, FL 32209 USA. RI Mokhtarian, Patricia/B-3374-2011 OI Mokhtarian, Patricia/0000-0001-7104-499X NR 28 TC 6 Z9 6 U1 2 U2 4 PU SOUTHERN MEDICAL ASSN PI BIRMINGHAM PA 35 LAKESHORE DR PO BOX 190088, BIRMINGHAM, AL 35219 USA SN 0038-4348 J9 SOUTHERN MED J JI South.Med.J. PD FEB PY 1998 VL 91 IS 2 BP 138 EP 143 PG 6 WC Medicine, General & Internal SC General & Internal Medicine GA 219YB UT WOS:000081635200003 PM 9496864 ER PT J AU Pelton, JJ AF Pelton, JJ TI Routine diagnostic laparoscopy is unnecessary in staging tumors of the pancreatic head SO SOUTHERN MEDICAL JOURNAL LA English DT Article; Proceedings Paper CT 49th Annual Cancer Symposium of the Society-of-Surgical-Oncology CY MAR 21-25, 1996 CL ATLANTA, GEORGIA SP Soc Surg Oncol ID PERITONEAL CYTOLOGY; COMPUTED-TOMOGRAPHY; CANCER; ADENOCARCINOMA; RESECTABILITY; NEOPLASMS AB Background, This study examined the success of computed tomography (CT) and angiography in predicting resectability of tumors of the pancreatic head and retrospectively examined whether diagnostic laparoscopy would have contributed additional staging information. Methods. The records of 67 patients with tumors of the pancreatic head were reviewed. Thirty-four patients had unresectable tumors, and 33 had tumors that were considered operable according to CT and angiographic findings. Results, Surgical resection was successful in 27 of 33 patients (82%). Surgical resection was abandoned in 6 cases due to inability to develop a plane behind the pancreatic head in 4 cases, peritoneal implants in 1 case, and an occult hepatic metastasis in 1 case. Diagnostic laparoscopy might have detected metastases in the latter two cases. Thus, in retrospect, diagnostic laparoscopy might have altered management in only 2 of 33 surgical cases (7%). Conclusions. The potentially limited usefulness of diagnostic laparoscopy in this series, in retrospect, raises the question of whether routinely using diagnostic laparoscopy in staging tumors of the pancreatic head is cost effective. C1 Wilford Hall USAF Med Ctr, Sect Surg Oncol, PSSG, Lackland AFB, TX 78236 USA. RP Pelton, JJ (reprint author), Wilford Hall USAF Med Ctr, Sect Surg Oncol, PSSG, 2200 Berquist Dr,Suite 1, Lackland AFB, TX 78236 USA. NR 15 TC 9 Z9 9 U1 0 U2 0 PU SOUTHERN MEDICAL ASSN PI BIRMINGHAM PA 35 LAKESHORE DR PO BOX 190088, BIRMINGHAM, AL 35219 USA SN 0038-4348 J9 SOUTHERN MED J JI South.Med.J. PD FEB PY 1998 VL 91 IS 2 BP 182 EP 186 PG 5 WC Medicine, General & Internal SC General & Internal Medicine GA 219YB UT WOS:000081635200011 PM 9496872 ER PT J AU Abramson, MA Chrissis, JW AF Abramson, MA Chrissis, JW TI Sequential quadratic programming and the ASTROS structural optimization system SO STRUCTURAL OPTIMIZATION LA English DT Article ID OPTIMAL-DESIGN; ALGORITHMS; IMPLEMENTATION AB The NLPQL sequential quadratic programming algorithm of Schittkowski is integrated with the Automated Structural Optimization System (ASTROS) and tested on three large-scale optimization problems, including one with constraints from multiple disciplines. Furthermore, the traditional solution approach, which involves the formulation and solution of an explicitly defined approximate problem during each iteration, is replaced by a simpler approach, in which the approximate problem is eliminated, and each finite element analysis is followed by one iteration of the optimizer. To compensate for the cost of additional analyses, a much more restrictive active set strategy is used. Although not much computational efficiency is gained, the alternative approach gives accurate solutions. The largest test problem, which had 1527 design variables and 6124 constraints was solved with ASTROS for the first time using a direct method. The resulting design represents the lowest weight feasible design recorded to date. C1 USAF, Seoul, South Korea. RP Abramson, MA (reprint author), USAF, Seoul, South Korea. NR 51 TC 2 Z9 2 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0934-4373 J9 STRUCT OPTIMIZATION JI Struct. Optim. PD FEB PY 1998 VL 15 IS 1 BP 24 EP 32 DI 10.1007/BF01197434 PG 9 WC Computer Science, Interdisciplinary Applications; Engineering, Multidisciplinary; Mechanics SC Computer Science; Engineering; Mechanics GA YY412 UT WOS:000072144000004 ER PT J AU Knolmayer, TJ Bowyer, MW Egan, JC Asbun, HJ AF Knolmayer, TJ Bowyer, MW Egan, JC Asbun, HJ TI The effects of pneumoperitoneum on gastric blood flow and traditional hemodynamic measurements SO SURGICAL ENDOSCOPY-ULTRASOUND AND INTERVENTIONAL TECHNIQUES LA English DT Article DE pneumoperitoneum; tonometry; intramucosal pH; laparoscopy ID PULMONARY-ARTERY CATHETERS; TONOMETRY; SECONDARY AB Background: The purpose of this study was to investigate the effects of increasing intraabdominal pressure (IP) on gastric blood flow, as measured by gastric tonometry and traditional hemodynamic measurements. Methods: Nine swine were anesthetized, intubated, and ventilated. Arterial and pulmonary artery catheters were placed by cutdown, a trocar was placed in the abdomen, and a gastric tonometer was placed in the stomach. Serial measurements of arterial and mixed venous blood gases, cardiac output, wedge pressure, lactic acid, and gastric intramucosal pH (pH(i)) were collected at intraperitoneal pressures of 0, 8, 10, 12, 14, 16, and 18 mm Hg after 30 min equilibration. Statistical analysis included Pearson correlation and Student's t test. Results: Increasing levels of IP were correlated with decreased arterial pH (p < 0.00003), increased mixed venous CO2 (p < 0.003), decreased intramucosal pH (p < 0.014), and increased arterial CO2 (p < 0.015). Gastric pH(i) differed significantly from baseline at IP levels of 16 mm Hg (p < 0.004) and 18 mm Hg (p < 0.01). No significant effects were observed on cardiac output or arterial lactate. No significant effects were observed in a control group that had been insufflated to 8 mm Hg and held constant over 3 h. Conclusions: In this model, gastric blood flow is adversely affected by increasing IP with pronounced effects in excess of 15 mm Hg. These results suggest that gastric tonometry may be used to monitor the adverse effects of pneumoperitoneum. Gastric pH(i) may be an earlier indicator of altered hemodynamic function during laparoscopy than traditional measures. C1 David Grant Med Ctr, Dept Surg, Travis AFB, CA 94535 USA. RP Bowyer, MW (reprint author), David Grant Med Ctr, Dept Surg, 101 Bodin Circle, Travis AFB, CA 94535 USA. NR 22 TC 25 Z9 28 U1 0 U2 2 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0930-2794 J9 SURG ENDOSC-ULTRAS JI Surg. Endosc.-Ultrason. Interv. Tech. PD FEB PY 1998 VL 12 IS 2 BP 115 EP 118 DI 10.1007/s004649900609 PG 4 WC Surgery SC Surgery GA YV523 UT WOS:000071833600006 PM 9479723 ER PT J AU Fang, ZQ Hemsky, JW Look, DC Mack, MP AF Fang, ZQ Hemsky, JW Look, DC Mack, MP TI Electron-irradiation-induced deep level in n-type GaN SO APPLIED PHYSICS LETTERS LA English DT Article ID VAPOR-PHASE EPITAXY; DEFECTS; GAAS AB Deep-level transient spectroscopy measurements of n-type GaN epitaxial layers irradiated with 1-MeV electrons reveal an irradiation-induced electron trap at E-C-0.18 eV. The production rate is approximately 0.2 cm(-1), lower than the rate of 1 cm(-1) found for the N vacancy by Wall-effect studies. The defect trap cannot be firmly identified at this time. (C) 1998 American Institute of Physics. C1 Wright State Univ, Dept Phys, Dayton, OH 45435 USA. Univ Calif Santa Barbara, Elect & Comp Engn & Mat Dept, Santa Barbara, CA 93106 USA. USAF, Wright Lab, Avion Directorate, Wright Patterson AFB, OH 45433 USA. RP Fang, ZQ (reprint author), Wright State Univ, Dept Phys, Dayton, OH 45435 USA. NR 16 TC 87 Z9 93 U1 1 U2 11 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JAN 26 PY 1998 VL 72 IS 4 BP 448 EP 449 DI 10.1063/1.120783 PG 2 WC Physics, Applied SC Physics GA YT563 UT WOS:000071619600019 ER PT J AU Bao, Y Tzou, HS Venkayya, VB AF Bao, Y Tzou, HS Venkayya, VB TI Analysis of non-linear piezothermoelastic laminated beams with electric and temperature effects SO JOURNAL OF SOUND AND VIBRATION LA English DT Article ID PIEZOELECTRIC ACTUATORS; PLATES AB Conventional analyses of piezoelectric laminated structures are based on linear theories. Investigations of non-linear characteristics are still relatively scarce. In this paper, static, dynamic, and control effects of a piezothermoelastic laminated beam with an initial non-linear large static deflection (the von Karman type geometric non-linear deformation) and temperature and electric inputs are studied. It is assumed that the piezoelectric layers are uniformly distributed on the top and bottom surfaces of the beam. Beam equations incorporating the non-linear deflections, piezoelectric layers, temperature and electric effects are simplified from the generic piezothermoelastic shell equations. Analytical solutions of non-linear static deflection and eigenvalue problems of the non-linearly deformed beam including temperature and electric effects are derived. Active control effects on non-linear static deflections and natural frequencies imposed by the piezoelectric actuators via high control voltages are investigated. A numerical example is provided and response behavior is investigated. (C) 1998 Academic Press Limited. C1 Univ Kentucky, Dept Mech Engn, Lexington, KY 40506 USA. USAF, Wright Lab, Flight Dynam Lab, Wright Patterson AFB, OH 45433 USA. RP Bao, Y (reprint author), Univ Kentucky, Dept Mech Engn, Lexington, KY 40506 USA. NR 16 TC 35 Z9 41 U1 0 U2 9 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0022-460X J9 J SOUND VIB JI J. Sound Vibr. PD JAN 22 PY 1998 VL 209 IS 3 BP 505 EP 518 DI 10.1006/jsvi.1997.1265 PG 14 WC Acoustics; Engineering, Mechanical; Mechanics SC Acoustics; Engineering; Mechanics GA YW368 UT WOS:000071928000007 ER PT J AU Turcotte, JS AF Turcotte, JS TI An analytical model for the forced response of cyclic structures SO JOURNAL OF SOUND AND VIBRATION LA English DT Letter C1 USAF, Inst Technol, Dept Aeronaut & Astronaut, Wright Patterson AFB, OH 45433 USA. RP Turcotte, JS (reprint author), USAF, Inst Technol, Dept Aeronaut & Astronaut, Wright Patterson AFB, OH 45433 USA. NR 5 TC 1 Z9 1 U1 0 U2 0 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0022-460X J9 J SOUND VIB JI J. Sound Vibr. PD JAN 22 PY 1998 VL 209 IS 3 BP 531 EP 536 DI 10.1006/jsvi.1997.1240 PG 6 WC Acoustics; Engineering, Mechanical; Mechanics SC Acoustics; Engineering; Mechanics GA YW368 UT WOS:000071928000009 ER PT J AU Cooper, RI Neuhauser, T AF Cooper, RI Neuhauser, T TI Borreliosis SO NEW ENGLAND JOURNAL OF MEDICINE LA English DT Article C1 Wilford Hall USAF Med Ctr, San Antonio, TX 78236 USA. RP Cooper, RI (reprint author), Wilford Hall USAF Med Ctr, San Antonio, TX 78236 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU MASS MEDICAL SOC PI BOSTON PA 10 SHATTUCK, BOSTON, MA 02115 USA SN 0028-4793 J9 NEW ENGL J MED JI N. Engl. J. Med. PD JAN 22 PY 1998 VL 338 IS 4 BP 231 EP 231 DI 10.1056/NEJM199801223380405 PG 1 WC Medicine, General & Internal SC General & Internal Medicine GA YT358 UT WOS:000071594100005 PM 9435329 ER PT J AU Bostwick, JM AF Bostwick, JM TI Treatment of suicidal patients SO NEW ENGLAND JOURNAL OF MEDICINE LA English DT Letter C1 Wilford Hall USAF Med Ctr, Lackland AFB, TX 78236 USA. RP Bostwick, JM (reprint author), Wilford Hall USAF Med Ctr, Lackland AFB, TX 78236 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU MASS MEDICAL SOC PI BOSTON PA 10 SHATTUCK, BOSTON, MA 02115 USA SN 0028-4793 J9 NEW ENGL J MED JI N. Engl. J. Med. PD JAN 22 PY 1998 VL 338 IS 4 BP 261 EP 261 PG 1 WC Medicine, General & Internal SC General & Internal Medicine GA YT358 UT WOS:000071594100012 PM 9441235 ER PT J AU Devilbiss, SL Yurkovich, S AF Devilbiss, SL Yurkovich, S TI Exploiting ellipsoidal parameter set estimates in H-infinity robust control design SO INTERNATIONAL JOURNAL OF CONTROL LA English DT Article ID SYSTEM-IDENTIFICATION; BOUNDED NOISE; ERROR-BOUNDS; MODEL; UNCERTAINTY AB The focus of this investigation is the exploitation of knowledge of an ellipsoidal bound on system parameters for the identification of modeling uncertainty information vital to the H-infinity, robust control designer, a time to frequency domain uncertainty transformation. The characterizations of parametric uncertainty as coprime factor and additive perturbations to a nominal plant model are addressed in worst-case analyses. A Kharitonov type analysis provides sufficient conditions for the use of an additive plant perturbation uncertainty characterization. Original optimization results for the coprime factor perturbation enable the essential task of loopshaping to be conducted in the control design phase. A novel scheme is introduced to interpolate magnitude samples of the perturbation bounding function and is further developed into a technique for identification of reduced-order perturbation weightings, vital for practical control design. An example serves to illustrate the success of the developed techniques. C1 USAF, Inst Technol, Dept Elect Engn, Wright Patterson AFB, OH 45433 USA. Ohio State Univ, Dept Elect Engn, Columbus, OH 43210 USA. RP Devilbiss, SL (reprint author), USAF, Inst Technol, Dept Elect Engn, 2950 P St, Wright Patterson AFB, OH 45433 USA. EM sdevilbi@afit.af.mil NR 26 TC 2 Z9 2 U1 0 U2 0 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON EC4A 3DE, ENGLAND SN 0020-7179 J9 INT J CONTROL JI Int. J. Control PD JAN 20 PY 1998 VL 69 IS 2 BP 271 EP 284 DI 10.1080/002071798222839 PG 14 WC Automation & Control Systems SC Automation & Control Systems GA YX946 UT WOS:000072096500006 ER PT J AU Prestidge, BR Prete, JJ Buchholz, TA Friedland, JL Stock, RG Grimm, PD Bice, WS AF Prestidge, BR Prete, JJ Buchholz, TA Friedland, JL Stock, RG Grimm, PD Bice, WS TI A survey of current clinical practice of permanent prostate brachytherapy in the United States SO INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS LA English DT Article DE prostate brachytherapy; clinical practice; survey ID CARCINOMA; IMPLANTATION AB Purpose: To help establish standards of care for transperineal interstitial permanent prostate brachytherapy (TIPPB) by obtaining data regarding current clinical practice among the most experienced TIPPB brachytherapists in the United States, Methods and Materials: The 70 brachytherapists who performed the greatest number of TIPPB cases in 1995 in the U.S. were surveyed. Each received a comprehensive four page questionnaire that included sections on training and experience, patient and isotope selection criteria, manpower, technique, and follow-up, Thirty-five (50%) surveys were ultimately returned after three mailings and follow-up phone calls, The cumulative experience of the 35 respondents represented approximately 45% of the total TIPPB volume in the U.S. for 1995, Respondents included 29 from the private sector and six from academic programs, Results: The median physician experience with TIPPB was reported as 4.9 years, Each performed an average of 73 TIPPB procedures in 1995 (range 40-300). This represented an increase in volume for most (74%) of the respondents, Sixty-three percent of the respondents attended a formal training course, 54% had TIPPB-specific residency training, and 31% had been proctored (16 had received two or more types of training experience), The most commonly reported selection criteria for implant alone was on Gleason score less than or equal to 7, PSA <15, less than or equal to Stage T2a, and gland size less than or equal to 60 cc, although no clear consensus was found. Fifty-four percent considered a history of TURF to be a relative contraindication, while 34% considered TURF to have no impact on patient selection. Eighty-six percent of respondents combine brachytherapy with external beam radiation in an average of 32% of their patients, Boosts were given with both I-125 prescribed to 120 Gy (75%) or (103)pd to 90 Gy (50%), Sixty percent reported using a Mick applicator, 46% prefer using preloaded needles, and (11%) use both techniques, Real-time imaging was usually performed with ultrasound (94%); most included fluoroscopy (60%). Definitions of PSA control varied widely, Conclusions: TIPPB clinical practice in the U.S. demonstrates similarities in technique, but differences in patient selection and definitions of biochemical control, It is, therefore, incumbent on those beginning TIPPB programs to carefully review the specific practice details of those institutions with a broad experience. (C) 1998 Elsevier Science Inc. C1 Wilford Hall USAF Med Ctr, Radiat Oncol PSRT, Dept Radiat Oncol, Lackland AFB, TX 78236 USA. RP Prestidge, BR (reprint author), Wilford Hall USAF Med Ctr, Radiat Oncol PSRT, Dept Radiat Oncol, 2200 Bergquist Dr,Ste 1, Lackland AFB, TX 78236 USA. NR 9 TC 73 Z9 77 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0360-3016 J9 INT J RADIAT ONCOL JI Int. J. Radiat. Oncol. Biol. Phys. PD JAN 15 PY 1998 VL 40 IS 2 BP 461 EP 465 DI 10.1016/S0360-3016(97)00715-3 PG 5 WC Oncology; Radiology, Nuclear Medicine & Medical Imaging SC Oncology; Radiology, Nuclear Medicine & Medical Imaging GA YT949 UT WOS:000071662700029 PM 9457836 ER PT J AU Liu, ZL Sarukura, N Dubinskii, MA Semashko, VV Naumov, AK Korableva, SL Abdulsabirov, RY AF Liu, ZL Sarukura, N Dubinskii, MA Semashko, VV Naumov, AK Korableva, SL Abdulsabirov, RY TI Tunable ultraviolet short-pulse generation from a Ce : LiCAF laser amplifier system and its sum-frequency mixing with an Nd : YAG laser SO JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS & EXPRESS LETTERS LA English DT Article DE all-solid-state; tunable; ultraviolet; short-pulse; amplification; sum-frequency mixing AB We developed an all-solid-state tunable short-pulse ultraviolet master oscillator and power amplifier (MOPA) system employing Ce3(+) : LiCaAlF6 (Ce:LiCAF) which can be pumped by the fourth harmonic of a Q-switched Nd:YAG laser. The demonstrated tuning range was 281 nm to 314 nm with the maximum output energy of 1 mJ from the oscillator maintaining short pulse characteristics. The maximum amplified pulse energy was 4 mJ after the double-pass amplifier. The tuning from 223 nm to 232 nm was realized by the sum-frequency-mixing of the Ce:LiCAF laser and the Q-sw Nd:YAG laser. C1 Inst Mol Sci, Okazaki, Aichi 444, Japan. USAF, Wright Lab, Wright Patterson AFB, OH 45433 USA. Kazan State Univ, Kazan 420008, Russia. RP Liu, ZL (reprint author), Inst Mol Sci, Okazaki, Aichi 444, Japan. EM zliu@ims.ac.jp RI Sarukura, Nobuhiko/F-3276-2015; Korableva, Stella/L-7304-2015; Semashko, Vadim/P-8360-2015; Naumov, Alexander/A-1581-2014 OI Sarukura, Nobuhiko/0000-0003-2353-645X; Korableva, Stella/0000-0002-8469-2512; Naumov, Alexander/0000-0003-2421-7602 NR 15 TC 10 Z9 10 U1 0 U2 11 PU JAPAN SOC APPLIED PHYSICS PI TOKYO PA KUDAN-KITA BUILDING 5TH FLOOR, 1-12-3 KUDAN-KITA, CHIYODA-KU, TOKYO, 102-0073, JAPAN SN 0021-4922 J9 JPN J APPL PHYS 2 JI Jpn. J. Appl. Phys. Part 2 - Lett. Express Lett. PD JAN 15 PY 1998 VL 37 IS 1AB BP L36 EP L38 DI 10.1143/JJAP.37.L36 PG 3 WC Physics, Applied SC Physics GA YW769 UT WOS:000071972200013 ER PT J AU Voevodin, AA Zabinski, JS AF Voevodin, AA Zabinski, JS TI Load-adaptive crystalline-amorphous nanocomposites SO JOURNAL OF MATERIALS SCIENCE LA English DT Article ID PULSED-LASER DEPOSITION; DIAMOND-LIKE CARBON; FILMS; COATINGS; RAMAN; CARBIDE; WEAR AB Advances in laser-assisted deposition have enabled the production of hard composites consisting of nanocrystalline and amorphous materials. Deposition conditions were selected to produce super-tough coatings, where controlled formation of dislocations, nanocracks and microcracks was permitted as stresses exceeded the elastic limit. This produced a self-adjustment in the composite deformation from hard elastic to quasiplastic, depending on the applied stress, which provided coating compliance and eliminated catastrophic failure typical of hard and brittle materials. The load-adaptive concept was used to design super-tough coatings consisting of nanocrystalline (10-50 nm) TiC grains embedded in an amorphous carbon matrix (about 30 vol%). They were deposited at near room temperature on steel surfaces and studied using X-ray photoelectron spectroscopy, X-ray diffraction, scanning electron microscopy, Raman spectroscopy, nanoindentation and scratch tests. Design concepts were verified using composition-structure-property investigations in the TiC-amorphous carbon (a-C) system. A fourfold increase in the toughness of hard (32 GPa) TiC-a-C composites was achieved in comparison with nanocrystalline single-phase TiC. C1 USAF, Wright Lab, Mat Directorate, Wright Patterson AFB, OH 45433 USA. RP USAF, Wright Lab, Mat Directorate, Wright Patterson AFB, OH 45433 USA. RI Voevodin, Andrey/I-6684-2013 NR 26 TC 162 Z9 166 U1 5 U2 22 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0022-2461 EI 1573-4803 J9 J MATER SCI JI J. Mater. Sci. PD JAN 15 PY 1998 VL 33 IS 2 BP 319 EP 327 DI 10.1023/A:1004307426887 PG 9 WC Materials Science, Multidisciplinary SC Materials Science GA YQ005 UT WOS:000071337900005 ER PT J AU Peterson, P Sharma, MP AF Peterson, P Sharma, MP TI Back-reflection pumping versus contradirectional pumping in upconversion solid state lasers SO OPTICS COMMUNICATIONS LA English DT Article ID DOPED FIBER AMPLIFIERS; UP-CONVERSION LASER; YAG LASERS; CW THEORY; BLUE; PERFORMANCE; TM AB We show that a change from contradirectional pumping to back-reflection pumping in upconversion lasers can reduce the threshold by 50%, increase the slope efficiency by 87%, and increase the laser output power by a factor of two to six depending on the pump powers. Our predictions are anchored to an upconversion Pr3+ ZBLAN fiber laser experiment to within 10%. (C) 1998 Published by Elsevier Science B.V. C1 USAF, Phillips Lab, Nonlinear Opt Ctr Technol, LIDD, Kirtland AFB, NM 87117 USA. Univ New Mexico, Dept Phys & Astron, Albuquerque, NM 87131 USA. RP Peterson, P (reprint author), USAF, Phillips Lab, Nonlinear Opt Ctr Technol, LIDD, 3550 Aberdeen Ave SE, Kirtland AFB, NM 87117 USA. NR 15 TC 2 Z9 2 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0030-4018 J9 OPT COMMUN JI Opt. Commun. PD JAN 15 PY 1998 VL 146 IS 1-6 BP 189 EP 195 DI 10.1016/S0030-4018(97)00505-1 PG 7 WC Optics SC Optics GA ZM329 UT WOS:000073527600038 ER PT J AU Elhamri, S Newrock, RS Mast, DB Ahoujja, M Mitchel, WC Redwing, JM Tischler, MA Flynn, JS AF Elhamri, S Newrock, RS Mast, DB Ahoujja, M Mitchel, WC Redwing, JM Tischler, MA Flynn, JS TI Al0.15Ga0.85N/GaN heterostructure: Effective mass and scattering times SO PHYSICAL REVIEW B LA English DT Article ID 2-DIMENSIONAL ELECTRON-GAS; MICROWAVE PERFORMANCE; THIN-FILMS; HETEROJUNCTIONS; SPECTROSCOPY; PARAMETERS; SAPPHIRE; NITRIDE; DIODES; STRAIN AB We have observed well-reolved Shubnikov-de Haas oscillations in the two-dimensional electron gas in AlxGa1-xN/GaN heterojunctions, and determined the GaN electron effective mass (m*) and the quantum scattering time (tau(q)). We found m*=0.18m(0)+/-0.02m(0) in agreement with theoretical calculations, but slightly smaller that the values previously reported from optical experiments. The value of tau(q) was found to be 0.13 x 10(-12) sec, which is about a factor of 6 smaller than the classical scattering time (tau(c)=0.77 x 10(-12) sec). This difference between tau(q) and tau(c) is attributed to a significant amount of small angle scattering, most likely due to charged defects the epilayer/substrate interface. C1 Univ Cincinnati, Dept Phys, Cincinnati, OH 45221 USA. USAF, Wright Lab, WL MLPO, Wright Patterson AFB, OH 45433 USA. Adv Technol Mat Inc, Danbury, CT 06810 USA. RP Elhamri, S (reprint author), Univ Cincinnati, Dept Phys, Cincinnati, OH 45221 USA. NR 34 TC 41 Z9 42 U1 1 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JAN 15 PY 1998 VL 57 IS 3 BP 1374 EP 1377 DI 10.1103/PhysRevB.57.1374 PG 4 WC Physics, Condensed Matter SC Physics GA YU434 UT WOS:000071716800019 ER PT J AU Berry, RJ Ehlers, CJ Burgess, DR Zachariah, MR Nyden, MR Schwartz, M AF Berry, RJ Ehlers, CJ Burgess, DR Zachariah, MR Nyden, MR Schwartz, M TI Halon thermochemistry: ab initio calculations of the enthalpies of formation of fluoroethanes SO THEOCHEM-JOURNAL OF MOLECULAR STRUCTURE LA English DT Article DE fluoroethane; heat of formation; bond additivity correction; thermochemistry; ab initio ID SET CORRELATION ENERGIES; VALENCE BOND MODEL; ELECTRONIC-STRUCTURE; MOLECULAR-ENERGIES; GAUSSIAN-1 THEORY; 2ND-ROW COMPOUNDS; CHEMISTRY; 1ST-ROW; ATOMS AB The ab initio G2, G2(MP2), CBS-4 and CBS-Q quantum mechanical protocols and the parameterized BAC-MP4 procedure were used to calculate the enthalpies of formation (a PO) of ethane and the complete series of fluoroethanes, C2Hx,F6-x,x=0-5., Results from all methods exhibited significant negative deviations from experiment. With the exception of the CBS-4 and BAC-MP4 procedures, the negative errors in the calculated enthalpies were observed to be linearly dependent upon the number of CF bonds in the molecule. Application of a bond additivity correction (BAG) parameter, Delta(C-F), derived in an earlier investigation of fluoro- and chlorofluoromethanes removed some although not all of the systematic deviations. Introduction of a heavy atom interaction parameter, representing the effect of an attached carbon on the C-F bond error, yielded corrected enthalpies which agree with experiment to within the reported uncertainties. The BAC-MP4 method, which has already been parameterized with generalized BACs, yields calculated enthalpies which average approximately 10 kJ mol(-1) below the experimental values of Delta(f)H degrees in the fluoroethanes. (C) 1998 Elsevier Science B.V. C1 USAF, Wright Lab, Ctr Computat Modeling Nonstruct Mat, Mat Directorate, Wright Patterson AFB, OH 45433 USA. Natl Inst Stand & Technol, Chem Sci & Technol Lab, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Bldg & Fire Res Lab, Gaithersburg, MD 20899 USA. Univ N Texas, Dept Chem, Denton, TX 76203 USA. RP Berry, RJ (reprint author), USAF, Wright Lab, Ctr Computat Modeling Nonstruct Mat, Mat Directorate, Wright Patterson AFB, OH 45433 USA. NR 34 TC 31 Z9 31 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0166-1280 J9 THEOCHEM-J MOL STRUC JI Theochem-J. Mol. Struct. PD JAN 12 PY 1998 VL 422 BP 89 EP 98 DI 10.1016/S0166-1280(97)00075-4 PG 10 WC Chemistry, Physical SC Chemistry GA YU994 UT WOS:000071777800010 ER PT J AU Goetz, RL Seetharaman, V AF Goetz, RL Seetharaman, V TI Modeling dynamic recrystallization using cellular automata SO SCRIPTA MATERIALIA LA English DT Article ID SIMULATION C1 USAF, Wright Lab, Mat Directorate, MLLM,WL, Wright Patterson AFB, OH 45433 USA. Universal Energy Syst Inc, Dayton, OH 45432 USA. RP Goetz, RL (reprint author), USAF, Wright Lab, Mat Directorate, MLLM,WL, Wright Patterson AFB, OH 45433 USA. NR 22 TC 86 Z9 113 U1 1 U2 7 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6462 J9 SCRIPTA MATER JI Scr. Mater. PD JAN 6 PY 1998 VL 38 IS 3 BP 405 EP 413 DI 10.1016/S1359-6462(97)00500-9 PG 9 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA YU649 UT WOS:000071739900008 ER PT J AU Vanheusden, K Kama, SP Pugh, RD Warren, WL Fleetwood, DM Devine, RAB Edwards, AH AF Vanheusden, K Kama, SP Pugh, RD Warren, WL Fleetwood, DM Devine, RAB Edwards, AH TI Thermally activated electron capture by mobile protons in SiO2 thin films SO APPLIED PHYSICS LETTERS LA English DT Article ID INDUCED INTERFACE STATES; SI/SIO2 INTERFACE; ATOMIC-HYDROGEN; DEFECTS; SILICON; BUILDUP; IRRADIATION; DEPENDENCE; CREATION; OXIDES AB The annihilation of mobile protons in thin SiO2 films by capture of ultraviolet-excited electrons has been analyzed for temperatures between 77 and 500 K. We observe a strong increase in proton annihilation with increasing temperature, and derive an activation energy for electron capture of about 0.2 eV. Based on quantum chemical [(OH)(3)Si](2)-O-H+ cluster calculations, we suggest photoexcitation of electrons from excited vibrational states of the ground electronic (valence band) state to a nearby excited electronic (SiO2 gap) state. It is argued that the latter excitation can result in H-0 formation at elevated temperatures. (C) 1998 American Institute of Physics. C1 USAF, Phillips Lab, Space Mission Technol Div, Kirtland AFB, NM 87117 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. France Telecom, Ctr Natl Etud Telecommun, F-38243 Meylan, France. Univ N Carolina, Dept Elect Engn, Charlotte, NC 28223 USA. RP Vanheusden, K (reprint author), USAF, Phillips Lab, Space Mission Technol Div, Kirtland AFB, NM 87117 USA. NR 20 TC 23 Z9 24 U1 0 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JAN 5 PY 1998 VL 72 IS 1 BP 28 EP 30 DI 10.1063/1.121447 PG 3 WC Physics, Applied SC Physics GA YP871 UT WOS:000071324400011 ER PT J AU Jenny, JR Van Nostrand, JE Kaspi, R AF Jenny, JR Van Nostrand, JE Kaspi, R TI The effect of Al on Ga desorption during gas source-molecular beam epitaxial growth of AlGaN SO APPLIED PHYSICS LETTERS LA English DT Article ID KINETICS; NITRIDE AB In this letter, we report on the impact aluminum has on gallium desorption kinetics in AlGaN alloys grown by gas source-molecular beam epitaxy. Aluminum is found to preferentially incorporate into the AlGaN films over the range of fluxes and temperatures investigated [0.05 less than or equal to J(i)(Ga) less than or equal to 0.5 ML/s; 0.1 less than or equal to J(i)(Al) less than or equal to 0.2 ML/s; 700 degrees C less than or equal to Ts less than or equal to 775 degrees C]. As a result, Ga is not observed to incorporate into the film until the NH3 flux exceeds that required to grow stoichiometric AIN. This preferential incorporation stems from two facts: (a) Al has an ammonia cracking efficiency similar to 2.5 times greater than that of Ga, and (b) Al participates in a Al-for-Ga exchange. As a result of these factors and under NH3 limited growth conditions, the aluminum mole fraction in a layer can be controlled by changing the incident NH3 flux. (C) 1998 American Institute of Physics. C1 AADP, Wright Lab, Wright Patterson AFB, OH 45433 USA. Univ New Mexico, Ctr High Technol Mat, Albuquerque, NM 87106 USA. RP Jenny, JR (reprint author), CREE Res Inc, 2810 Meridian Pkwy, Durham, NC 27713 USA. NR 11 TC 15 Z9 16 U1 1 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JAN 5 PY 1998 VL 72 IS 1 BP 85 EP 87 DI 10.1063/1.120652 PG 3 WC Physics, Applied SC Physics GA YP871 UT WOS:000071324400030 ER PT J AU Melchionda, RJ AF Melchionda, RJ TI Restore sampling mission SO AVIATION WEEK & SPACE TECHNOLOGY LA English DT Letter C1 USAF, Dover, DE 19901 USA. RP Melchionda, RJ (reprint author), USAF, Dover, DE 19901 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MCGRAW HILL INC PI NEW YORK PA 1221 AVENUE OF THE AMERICAS, NEW YORK, NY 10020 USA SN 0005-2175 J9 AVIAT WEEK SPACE TEC JI Aviat. Week Space Technol. PD JAN 5 PY 1998 VL 148 IS 1 BP 6 EP 6 PG 1 WC Engineering, Aerospace SC Engineering GA YP848 UT WOS:000071321900003 ER PT J AU Shan, XW He, XY AF Shan, XW He, XY TI Discretization of the velocity space in the solution of the Boltzmann equation SO PHYSICAL REVIEW LETTERS LA English DT Article ID NAVIER-STOKES EQUATION; LATTICE AB We point out an equivalence between the discrete velocity method of solving the Boltzmann equation, of which the lattice Boltzmann equation method is a special example, and the approximations to the Boltzmann equation by a Hermite polynomial expansion. Discretizing the Boltzmann equation with a Bhatnagar-Gross-Krook collision term at the velocities that correspond to the nodes of a Hermite quadrature is shown to be equivalent to truncating the Hermite expansion of the distribution function to the corresponding order. The truncated part of the distribution has no contribution to the moments of low orders and is negligible at small Mach numbers. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Complex Syst Grp, Los Alamos, NM 87545 USA. USAF, Res Lab, GPOF, PL, Hanscom AFB, MA 01731 USA. RP Shan, XW (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Complex Syst Grp, MS-B213, Los Alamos, NM 87545 USA. RI Shan, Xiaowen/H-2836-2013 OI Shan, Xiaowen/0000-0002-6350-9248 NR 17 TC 212 Z9 215 U1 2 U2 27 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 JAN 5 PY 1998 VL 80 IS 1 BP 65 EP 68 DI 10.1103/PhysRevLett.80.65 PG 4 WC Physics, Multidisciplinary SC Physics GA YQ289 UT WOS:000071370400017 ER PT B AU Moore, TC AF Moore, TC GP AMER METEOROL SOC AMER METEOROL SOC TI Vertical distribution of oxides of nitrogen in the semi-urban planetary boundary layer: Mixing ratios, sources and transport SO 10TH JOINT CONFERENCE ON THE APPLICATIONS OF AIR POLLUTION METEOROLOGY WITH THE A&WMA LA English DT Proceedings Paper CT 10th Joint Conference on the Applications of Air Pollution Meteorology with the A&WMA / American-Meteorological-Society CY JAN 11-16, 1998 CL PHOENIX, AZ SP Air & Waste Management Assoc, Amer Meteorol Soc C1 Armstrong Lab, Brooks AFB, TX 78235 USA. RP Moore, TC (reprint author), N Carolina State Univ, Dept Marine Earth & Atmospher Sci, Box 8208, Raleigh, NC 27695 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 1998 BP 82 EP 85 PG 4 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA BL92P UT WOS:000077162100018 ER PT B AU Doran, J Roeder, W Toth, Z Zhu, Y Venable, B Craig, B Ries, V McDonald, D AF Doran, J Roeder, W Toth, Z Zhu, Y Venable, B Craig, B Ries, V McDonald, D GP AMS AMS TI The AFWA 45 WS NCEP ensemble test (A4NET): An operational point verification of ensemble precipitation probability forecasts SO 12TH CONFERENCE ON NUMERICAL WEATHER PREDICTION LA English DT Proceedings Paper CT 12th Conference on Numerical Weather Prediction CY JAN 11-16, 1998 CL PHOENIX, AZ SP Amer Meteorol Soc (AMS) C1 USAF, Weather Agcy, DNXT, Offutt AFB, NE 68113 USA. RP Doran, J (reprint author), USAF, Weather Agcy, DNXT, 106 Peacekeeper Dr,Suite 2N3, Offutt AFB, NE 68113 USA. RI Toth, Zoltan/I-6624-2015 OI Toth, Zoltan/0000-0002-9635-9194 NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 1998 BP 281 EP 285 PG 5 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BM02Q UT WOS:000077436900090 ER PT B AU Vornbrock, F AF Vornbrock, F GP UWM/DE UWM/DE TI Lessons civilians can learn from air force distance learning programs: The good, the bad, and the ugly SO 14TH ANNUAL CONFERENCE ON DISTANCE TEACHING AND LEARNING, PROCEEDINGS LA English DT Proceedings Paper CT 14th Annual Conference on Distance Teaching and Learning CY AUG 05-07, 1998 CL MADISON, WI C1 USAF, Distance Learning Off, Maxwell AFB, AL 36112 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIV WISCONSIN MADISON PI MADISON PA 1050 UNIV AVE, B136 LATHROP HALL, MADISON, WI 53706 USA PY 1998 BP 413 EP 416 PG 4 WC Education & Educational Research SC Education & Educational Research GA BL87M UT WOS:000077020900067 ER PT B AU Bauman, WH Lefevre, RJ AF Bauman, WH Lefevre, RJ GP AMER METEOROL SOC AMER METEOROL SOC AMER METEOROL SOC TI Air Force Weather Global Theater Weather Analysis and Prediction System SO 16TH CONFERENCE ON WEATHER ANALYSIS AND FORECASTING / SYMPOSIUM ON THE RESEARCH FOCI OF THE U.S. WEATHER RESEARCH PROGRAM LA English DT Proceedings Paper CT 16th Conference on Weather Analysis and Forecasting / Symposium on the Research Foci of the US Weather Research Program CY JAN 11-16, 1998 CL PHOENIX, AZ SP Amer Meteorol Soc C1 AFWA, DNX, Scott AFB, IL 62225 USA. RP Bauman, WH (reprint author), AFWA, DNX, 102 W Losey St,Room 105, Scott AFB, IL 62225 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 1998 BP 247 EP 248 PG 2 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BL92Q UT WOS:000077162300085 ER PT B AU Roeder, WP Pinder, CS AF Roeder, WP Pinder, CS GP AMER METEOROL SOC AMER METEOROL SOC AMER METEOROL SOC TI Lightning forecasting empirical techniques for central Florida in support of America's space program SO 16TH CONFERENCE ON WEATHER ANALYSIS AND FORECASTING / SYMPOSIUM ON THE RESEARCH FOCI OF THE U.S. WEATHER RESEARCH PROGRAM LA English DT Proceedings Paper CT 16th Conference on Weather Analysis and Forecasting / Symposium on the Research Foci of the US Weather Research Program CY JAN 11-16, 1998 CL PHOENIX, AZ SP Amer Meteorol Soc RP Roeder, WP (reprint author), WS DOU 45, 1201 Minuteman St, Patrick AFB, FL 32925 USA. NR 0 TC 4 Z9 6 U1 0 U2 1 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 1998 BP 475 EP 477 PG 3 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BL92Q UT WOS:000077162300160 ER PT B AU Seaford, ML Tomich, DH Eyink, KG Lampert, WV Ejeckam, FE Lo, YH AF Seaford, ML Tomich, DH Eyink, KG Lampert, WV Ejeckam, FE Lo, YH BE Melloch, M Reed, MA TI Comparison of MBE grown InSb on CU substrates using different sacrificial layers SO 1997 IEEE INTERNATIONAL SYMPOSIUM ON COMPOUND SEMICONDUCTORS LA English DT Proceedings Paper CT 24th IEEE International Symposium on Compound Semiconductors CY SEP 08-11, 1997 CL SAN DIEGO, CA SP IEEE, Motorola, USN, Off Naval Res, Siemens, Aixtron, EPI AB InSb epitaxial layers with approximately 15% lattice mismatched to GaAs were grown on a conventional GaAs substrate and compliant universal (CU) substrates using various sacrificial layers. Transmission electron microscopy studies showed dislocation free InSb films grown on the CU substrate using the AlGaAs sacrificial layer, whereas the InSb films on the normal GaAs substrate and the CU substrate with the InGaP sacrificial layer exhibited dislocation densities as high as 10(11) cm(-2). Reciprocal space maps of the (004) peak for the dislocation free InSb layer revealed a large mosaic spread of similar to 0.25 degrees. Using atomic force microscopy on the dislocation free InSb layer, the mosaic spread was found to be generated by a periodic surface undulation with a three micron period and 700 Angstrom amplitude. C1 USAF, Res Lab, Mat Directorate, Wright Patterson AFB, OH 45433 USA. RP Seaford, ML (reprint author), USAF, Res Lab, Mat Directorate, Wright Patterson AFB, OH 45433 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-3883-9 PY 1998 BP 29 EP 32 PG 4 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Materials Science, Characterization & Testing; Optics; Physics, Applied SC Engineering; Materials Science; Optics; Physics GA BL44M UT WOS:000075543900006 ER PT B AU Dorsey, DL Mahalingam, K AF Dorsey, DL Mahalingam, K BE Melloch, M Reed, MA TI A comprehensive atomic-level simulator for AlGaAs/GaAs (001) MBE SO 1997 IEEE INTERNATIONAL SYMPOSIUM ON COMPOUND SEMICONDUCTORS LA English DT Proceedings Paper CT 24th IEEE International Symposium on Compound Semiconductors CY SEP 08-11, 1997 CL SAN DIEGO, CA SP IEEE, Motorola, USN, Off Naval Res, Siemens, Aixtron, EPI AB A comprehensive, quantitatively accurate, atomic-level simulator for AlGaAs/GaAs (001) MBE has been developed. The kinetic Monte Carlo method was applied within the solid-on-solid approximation, explicitly accounting for deposition, desorption and surface diffusion of both the group III and group V species. In contrast to previous efforts, the kinetic parameters of the model (neighbor interaction energies) were determined by matching model results to gallium desorption transients measured by desorption mass spectrometry (DMS) during GaAs/AlGaAs/GaAs heterointerface formation. The model reproduces these complex transients, and predicts the stoichiometry profile near the GaAs/AlGaAs heterointerface. C1 USAF, Res Lab, Mat & Mfg Directorate, Wright Patterson AFB, OH 45433 USA. RP Dorsey, DL (reprint author), USAF, Res Lab, Mat & Mfg Directorate, WL MLPO Bldg 651,3005 P St Ste 6, Wright Patterson AFB, OH 45433 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-3883-9 PY 1998 BP 147 EP 150 PG 4 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Materials Science, Characterization & Testing; Optics; Physics, Applied SC Engineering; Materials Science; Optics; Physics GA BL44M UT WOS:000075543900034 ER PT B AU Schuermeyer, F Cheskis, D Goldman, RS Wieder, HH AF Schuermeyer, F Cheskis, D Goldman, RS Wieder, HH BE Melloch, M Reed, MA TI Photoconduction studies on InGaAs HEMTs SO 1997 IEEE INTERNATIONAL SYMPOSIUM ON COMPOUND SEMICONDUCTORS LA English DT Proceedings Paper CT 24th IEEE International Symposium on Compound Semiconductors CY SEP 08-11, 1997 CL SAN DIEGO, CA SP IEEE, Motorola, USN, Off Naval Res, Siemens, Aixtron, EPI AB Photoconduction measurements made on In(0.53)Gs(0.47)As channel HEMTs indicate that the threshold energy for photoconduction corresponds to the bandgap of the quantum well and the absorption edge of the substrate. Many interband transitions are observed which can be correlated with the electronic subbands of the quantum well. Strong confinement of photogenerated holes is associated with a large modulation of the HEMT threshold voltage. C1 Wright Lab, AADD, Wright Patterson AFB, OH 45433 USA. RP Schuermeyer, F (reprint author), Wright Lab, AADD, Wright Patterson AFB, OH 45433 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-3883-9 PY 1998 BP 303 EP 306 PG 4 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Materials Science, Characterization & Testing; Optics; Physics, Applied SC Engineering; Materials Science; Optics; Physics GA BL44M UT WOS:000075543900072 ER PT B AU Lott, JA Noble, MJ AF Lott, JA Noble, MJ BE Melloch, M Reed, MA TI Model of intra and extracavity photodetection for planar resonant cavity light emitting diodes SO 1997 IEEE INTERNATIONAL SYMPOSIUM ON COMPOUND SEMICONDUCTORS LA English DT Proceedings Paper CT 24th IEEE International Symposium on Compound Semiconductors CY SEP 08-11, 1997 CL SAN DIEGO, CA SP IEEE, Motorola, USN, Off Naval Res, Siemens, Aixtron, EPI AB A classical model of spontaneous emission in resonant cavity light emitting diodes is developed. The model is based on a plane wave expansion of a randomly distributed ensemble of noninteracting optical dipole emitter pairs placed within a planar microcavity. The model accounts for losses due to leaky guided modes and intracavity absorption. Given an arbitrary device structure, the model predicts the total power emitted, the radiation pattern, and the relative magnitude of photocurrent generated in an intra or extracavity photodetector. Selected modeling results for an example device emitting at 650 nm are included. C1 USAF, Inst Technol, Dept Elect & Comp Engn, Wright Patterson AFB, OH 45433 USA. RP Lott, JA (reprint author), USAF, Inst Technol, Dept Elect & Comp Engn, 2950 P St Bldg 640, Wright Patterson AFB, OH 45433 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-3883-9 PY 1998 BP 585 EP 588 PG 4 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Materials Science, Characterization & Testing; Optics; Physics, Applied SC Engineering; Materials Science; Optics; Physics GA BL44M UT WOS:000075543900139 ER PT B AU Evans, BL Martin, JB Burggraf, LW Roggemann, MC AF Evans, BL Martin, JB Burggraf, LW Roggemann, MC BE Nalcioglu, O TI Nondestructive inspection using Compton scatter tomography SO 1997 IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD, VOLS 1 & 2 LA English DT Proceedings Paper CT 1997 IEEE Nuclear Science Symposium and Medical Imaging Conference CY NOV 09-15, 1997 CL ALBUQUERQUE, NM SP IEEE AB A method for non-invasively generating tomographic images of electron density in materials using Compton scattered gamma rays is investigated. Electron density is an indicator of density or composition changes in a material. In Compton scatter tomography, the energy distribution of monoenergetic gamma rays is measured after scattering from a material target. Measuring a scattered gamma ray's energy localizes the scattering position to a definable region of the sample. We develop an analytic computational model to study the image quality of a realistic system. In particular, the deleterious effects of finite source and detector size, Compton broadening, and Poisson noise are investigated. A backprojection algorithm is presented to demonstrate the impact of these effects on image reconstruction and contrast recovery. Detection of corrosion in low-Z materials is an application of interest, and is used to study the Compton scatter tomography technique. C1 USAF, Inst Technol, Dept Engn Phys, Wright Patterson AFB, OH 45433 USA. RP Evans, BL (reprint author), USAF, Inst Technol, Dept Engn Phys, 2950 P St, Wright Patterson AFB, OH 45433 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4259-3 PY 1998 BP 386 EP 390 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Physics; Radiology, Nuclear Medicine & Medical Imaging GA BL13T UT WOS:000074401900082 ER PT B AU Paschkewitz, JS AF Paschkewitz, JS GP IEEE, DIELECT & INSULAT SOC IEEE, DIELECT & INSULAT SOC TI Exposure testing of dielectric liquids for aircraft EHD heat exchanger applications SO 1998 ANNUAL REPORT CONFERENCE ON ELECTRICAL INSULATION AND DIELECTRIC PHENOMENA, VOLS 1 AND 2 LA English DT Proceedings Paper CT 67th Annual Conference on Electrical Insulation and Dielectric Phenomena CY OCT 25-28, 1998 CL ATLANTA, GA SP IEEE, Dielect & Insulat Soc AB An eight-week test evaluated long-term exposure effects of pulsed high voltage electric fields on fluid properties. Two electronics cooling fluids suitable for aviation use were tested: FC-72, a perfluorocarbon, and PAO, or polyalphaolefin, a dielectric cooling oil. These fluids were exposed to approximately 10,000 on-off cycles and tested for changes in fluid physical and electrical properties and chemical composition. Test results showed no significant changes in FC-72 properties, but a substantial reduction in the dielectric strength and increase in electrical conductivity of PAO. Further testing is required to isolate the cause of these changes. C1 USAF, Res Lab, Tranparency & Thermal Syst Sect, Wright Patterson AFB, OH 45433 USA. RP Paschkewitz, JS (reprint author), USAF, Res Lab, Tranparency & Thermal Syst Sect, Wright Patterson AFB, OH 45433 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-5035-9 PY 1998 BP 166 EP 169 PG 4 WC Engineering, Electrical & Electronic SC Engineering GA BM01M UT WOS:000077417300037 ER PT B AU Lehr, JM AF Lehr, JM GP IEEE, DIELECT & INSULAT SOC IEEE, DIELECT & INSULAT SOC TI Effect of de-aeration on the electrical breakdown characteristics of water SO 1998 ANNUAL REPORT CONFERENCE ON ELECTRICAL INSULATION AND DIELECTRIC PHENOMENA, VOLS 1 AND 2 LA English DT Proceedings Paper CT 67th Annual Conference on Electrical Insulation and Dielectric Phenomena CY OCT 25-28, 1998 CL ATLANTA, GA SP IEEE, Dielect & Insulat Soc AB In the study of electrical breakdown in liquids, attention is typically paid to the contamination of the liquid, and particularly ionic impurities. However, the purity of the sample is also compromised by dissolved gases as well as ionically charged species. To test the effect of de aeration, water, a highly gas-soluble liquid, was chosen as the test liquid. The delay time to breakdown was measured under the action of a rectangular pulse of 50 kV peak amplitude, 4 mu s duration and 250 ns risetime to planar electrodes. The de-aeration apparatus and a test to verify the complete degassing of the water is described. The breakdown properties axe strongly affected by the presence of dissolved air: the air saturated water takes significantly longer to breakdown. The experiment suggests that the breakdown strength in same liquids may be raised by careful degassing. C1 USAF, Res Lab, Directed Energy Directorate, High Power Syst Branch, Kirtland AFB, NM 87117 USA. RP Lehr, JM (reprint author), USAF, Res Lab, Directed Energy Directorate, High Power Syst Branch, 3550 Aberdeen Ave SE, Kirtland AFB, NM 87117 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-5035-9 PY 1998 BP 460 EP 463 DI 10.1109/CEIDP.1998.732935 PG 4 WC Engineering, Electrical & Electronic SC Engineering GA BM01M UT WOS:000077417300103 ER PT S AU Meink, TE AF Meink, TE GP IEEE TI Composite grid vs. composite sandwich: A comparison based on payload shroud requirements SO 1998 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOL 1 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 21-28, 1998 CL ASPEN, CO SP IEEE, Aerosp & Electr Syst Soc AB The use of sandwich construction, which is arguably the most structurally efficient structure, gives large weight savings over metallic structures. The substitution of Advanced Grid Stiffened (AGS) structures is not targeted at reducing structural weight, but at reducing manufacturing cost and the acoustic transmission characteristics of the payload shroud. To better quantify the advantages or disadvantages between the structural types a design comparison is made based on a composite sandwich shroud, currently in production, and an AGS Composite shroud. These shrouds are in the 4-meter class. The analysis includes: stiffness (deflection limits), material failure, stability, and natural frequency response. These analyses were done using a combination of Finite Element Modeling (FEM), and grid optimization programs. AGS structures are characterized by a lattice of rigid, interconnected ribs, which proves to be a highly efficient design. AGS structures also offer other inherent advantages such as high impact resistance. When damaged, delamination and crack propagation tend to remain isolated to a cell. They also do not suffer from moisture infiltration and the associated problems such as face sheet to core delamination, corrosion, and increased weight[l]. One of the most valuable assets of AGS structures is their high potential for automation. Several AGS structures have been successfully manufactured at the Air Force's Phillip Laboratories using automated techniques[5]. These techniques have been verified by flight qualification and flight demonstration on the Combined Experiments Program (CEP) Sub-Orbital launch. C1 USAF, Phillips Lab, Space Vehicle Technol Div, Kirtland AFB, NM 87117 USA. RP Meink, TE (reprint author), USAF, Phillips Lab, Space Vehicle Technol Div, 3550 Aberdeen Ave, Kirtland AFB, NM 87117 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-4311-5 J9 AEROSP CONF PROC PY 1998 BP 215 EP 220 PG 6 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA BL20E UT WOS:000074664600022 ER PT S AU Ewing, RL Hines, JW Peterson, GD Rubeiz, M AF Ewing, RL Hines, JW Peterson, GD Rubeiz, M GP IEEE TI VHDL-AMS design for flight control systems SO 1998 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOL 1 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 21-28, 1998 CL ASPEN, CO SP IEEE, Aerosp & Electr Syst Soc AB This paper investigates a method to address the present and future flight control system analog IC requirements. The explosive growth in the development of VHDL-AMS (Analog Mixed Signal) has initiated the need for commercial CAD products based on mixed-signal design methodologies. Several design methodologies exist for developing analog-digital interface circuits. These methodologies range from the use of commercial off the shelf parts (COTS) to custom analog Integrated Circuit (IC) components that meet performance specifications. The current VHDL-AMS language has potential problems in the design of custom analog IC components in terms of scaling the internal device dimensions and maintaining robust design performance. As an example, a digital controller is being used in flight control systems. The digital controller is an embedded processor, which, through a D/A, controls the actuators of the aircraft. Sensors from the actuators are fed back through an A/D, a low-pass Alter, and then to the embedded processor, completing the loop. In this example, the VHDL-AMS language is used to describe the electronic elements of the flight control system, and also, uniquely, the digital compensator. The digital compensator and filter are designed with the use of quantitative feedback theory (QFT)-theory that emphasizes the use of feedback to achieve the desired system performance tolerances despite plant uncertainty and disturbances. The QFT design technique uses the frequency domain, and has been developed for both linear and nonlinear, time-invariant and time-varying, continuous and sampled data, uncertain multiple-input signal-output (MISO) and multiple-input multiple-output (MIMO) plants, and distributed systems (partial differential equations). The Anal QFT VHDL-AMS design, is tuned for performance to the bounds of uncertainty, the parameter tolerances, and the sampling time of the A/D and D/A, and may be used for either COTS design or custom analog IC components. C1 USAF, Res Lab, AFRL, IFTA, Wright Patterson AFB, OH 45433 USA. RP Ewing, RL (reprint author), USAF, Res Lab, AFRL, IFTA, Bldg 620,Room N3F22,2241 Avion Circle, Wright Patterson AFB, OH 45433 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-4311-5 J9 AEROSP CONF PROC PY 1998 BP 223 EP 229 PG 7 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA BL20E UT WOS:000074664600023 ER PT S AU Peterson, GD Hines, JW AF Peterson, GD Hines, JW GP IEEE TI Advanced avionics system development: Achieving systems superiority through design automation SO 1998 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOL 1 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 21-28, 1998 CL ASPEN, CO SP IEEE, Aerosp & Electr Syst Soc AB Avionics systems in advanced aircraft provide the improved capability critical to achieving mission success for the war fighter. As the costs associated with aircraft avionics continue to mount, improved weapons system acquisition and support depends on cost-effective design methodologies and accurate design documentation. This paper explores how the standard hardware description language VHDL serves a critical role in effective acquisition of digital electronic systems. With the ever-increasing complexity of systems and interdependency of hardware and software through-out the weapon system life cycle, it is imperative to facilitate the development of effective standards, methodologies, and tools which support the acquisition of complex systems consisting of sophisticated hardware and software. For cost-effective development of weapons systems which may have operational deployment spanning decades, program offices need to exploit the best commercial design practices and adapt them to support concurrent engineering considerations. Programs such as the DARPA Rapid Prototyping of Application Specific Signal Processors (RASSP) effort demonstrate 3X improvements in avionics system development by advocating approaches such as using COTS (Commercial Off The Shelf) parts, Model Year Upgrades, and virtual prototyping as techniques to leverage the economies of scale driving commercial electronics cost and performance improvements. Wright Laboratory programs focusing on electronic systems design automation provide complementary improvements in design, documentation, and maintenance capabilities. Results from this research supports acquisition reform efforts to streamline the weapons system procurement process and provide design management techniques. At the same time, while the Department of Defense (DoD) is moving away from dictating standards in contracting, the electronics industry continues to embrace open standards as a means to ensure hardware and software component compatibility. The question arises: what methodology and standards developments are necessary to support the continuing development of sophisticated weapons systems for the military? To address this question, the paper explores methodological needs for hardware and software design, manufacturability, test, and related issues to provide context and motivation before describing ongoing work to meet these needs. C1 USAF, Wright Lab, Avion Directorate, Wright Patterson AFB, OH 45433 USA. RP Peterson, GD (reprint author), USAF, Wright Lab, Avion Directorate, 2241 Avion Circle,Rm N3-F22, Wright Patterson AFB, OH 45433 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-4311-5 J9 AEROSP CONF PROC PY 1998 BP 231 EP 238 PG 8 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA BL20E UT WOS:000074664600024 ER PT S AU McQuay, WK AF McQuay, WK GP IEEE TI A Collaborative Engineering Environment for 21st Century avionics SO 1998 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOL 1 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 21-28, 1998 CL ASPEN, CO SP IEEE, Aerosp & Electr Syst Soc AB Collaborative engineering and virtual prototyping is the application of advanced distributed modeling and simulation and engineering tools in an integrated environment to support technology development, system design, performance, cost, and producibility trade-off analyses throughout the entire product and system engineering life cycle. The Sensors and Information Directorates, Air Force Research Laboratory (AFRL) have initiated a major effort to implement a Collaborative Engineering Environment (CEE) to provide the infrastructure and development methodology required for affordable and timely avionics for the 21(st) Century warfighter. The CEE concept is a major cultural change in the technology development process that involves applying state-of-the-art simulation and information sharing technology to the way we do business. CEE enables partnerships among the laboratories, industry, and the warfighter to accelerate the development and transition of leading edge technology to the operational weapon systems. C1 USAF, Res Lab, Wright Patterson AFB, OH 45433 USA. RP McQuay, WK (reprint author), USAF, Res Lab, 2241 Av Cir,RM N3R22, Wright Patterson AFB, OH 45433 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-4311-5 J9 AEROSP CONF PROC PY 1998 BP 255 EP 262 PG 8 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA BL20E UT WOS:000074664600027 ER PT S AU McManamon, PF Watson, EA Eismann, MT AF McManamon, PF Watson, EA Eismann, MT GP IEEE TI Suggestions for low cost multifunction sensing SO 1998 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOL 1 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 21-28, 1998 CL ASPEN, CO SP IEEE, Aerosp & Electr Syst Soc AB Modern aerospace vehicles must perform a large number of sensing functions, but to fit within modernization budgets they must do it at very low cost. A modular, multifunction, open architecture, sensing system required of EO systems on a combat aircraft will be discussed. Multiple aperture modules will be used, and one or more systems modules will encompass common components. Target acquisition will be analyzed for a large forward looking aperture, while missile warning, situational awareness, IRCM, and other functions will be considered through multiple situational awareness apertures. A low cost multifunction RF system that is divided into three areas defined by analog to digital, A/D, converter state of the art will be discussed. C1 USAF, Res Lab, Sensors Directorate, AFRL,SNJ, Wright Patterson AFB, OH 45433 USA. RP McManamon, PF (reprint author), USAF, Res Lab, Sensors Directorate, AFRL,SNJ, Bldg 620,2241 Av Circle, Wright Patterson AFB, OH 45433 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-4311-5 J9 AEROSP CONF PROC PY 1998 BP 283 EP 307 PG 25 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA BL20E UT WOS:000074664600029 ER PT S AU Zelnio, EG AF Zelnio, EG GP IEEE TI Advanced decision-making systems in future avionics: Automatic target recognition example SO 1998 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOL 1 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 21-28, 1998 CL ASPEN, CO SP IEEE, Aerosp & Electr Syst Soc AB In future avionics systems, there will be a stronger and stronger pull for more automation of decisionmaking functions. The nature of these decision-making functions will be of such complexity that exhaustive testing of all possible decisions will be impossible. Further, the complexity will also preclude exhaustive "training" of the decision-making systems such as the training required of learning-based paradigms like neural networks. The primary thesis of this paper will advocate a change of focus in training and testing procedures for advanced decision-making systems such as automatic target recognizers (ATR's). Whereas currently, the predominant state of the art in ATR testing is preoccupied on making sure that the training and testing data come from the same population. This common procedure helps promote excellent results but does not provide insight into performance of the system under real world conditions. Rather, the focus should be on whether the testing is representative of the real world or whether it even scales to the complexity of the real world situations. Testing performed in this way will result in different approaches to decision-making systems such as ATR and, it is believed, will accelerate progress in ATR and other decision-making functions. C1 USAF, Res Lab, Sensors Directorate, Wright Patterson AFB, OH 45433 USA. RP Zelnio, EG (reprint author), USAF, Res Lab, Sensors Directorate, Wright Patterson AFB, OH 45433 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-4311-5 J9 AEROSP CONF PROC PY 1998 BP 309 EP 313 PG 5 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA BL20E UT WOS:000074664600030 ER PT S AU Martinez, EJ Bobb, RL AF Martinez, EJ Bobb, RL GP IEEE TI High performance Analog-to-Digital Converter technology for military avionics applications SO 1998 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOL 1 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 21-28, 1998 CL ASPEN, CO SP IEEE, Aerosp & Electr Syst Soc AB The signal processing requirements of military avionics systems are constantly increasing to meet the threats of the next century. This is especially true as the digital interface moves closer to the sensor/antenna and the Analog-to-Digital Converter (ADC) performance requirements become a major contributor to spaceborne data and signal/sensor processors and mission management specifications. The benefits of moving the digital interface closer to the sensor/antenna in avionics systems can be classified in four different categories: affordability, reliability and maintainability, physical, and performance. This reduction in RF downconversion stages as the digital interface migrates toward the sensor can result in some difficult ADC requirements that can not currently be met by commercial technologies. It is the intention of this presentation to expose the aerospace community to these emerging requirements for radar, communication and navigation (CNI), and electronic warfare missions. In addition to these requirements, we are presenting some examples of current state-of-the-art ADCs, their technology limitations, and briefly discuss potential applications in avionics systems. We have also included in this presentation a brief discussion on the fundamental and physical limitations that impair the progress of current and future ADC technologies. This presentation will conclude with a technology forecast, and an estimate on ADC availability for future avionics systems. C1 USAF, Res Lab, Electron Devices Div, WL,AADD, Wright Patterson AFB, OH 45433 USA. RP Martinez, EJ (reprint author), USAF, Res Lab, Electron Devices Div, WL,AADD, 2241 Av Circle, Wright Patterson AFB, OH 45433 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-4311-5 J9 AEROSP CONF PROC PY 1998 BP 315 EP 330 PG 16 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA BL20E UT WOS:000074664600031 ER PT B AU Peters, KW Bishop, JA Wilkes, JM AF Peters, KW Bishop, JA Wilkes, JM GP IEEE TI An analysis of membrane mirrors for use in large aperture imaging systems SO 1998 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOL 2 LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 21-28, 1998 CL ASPEN, CO SP IEEE, Aerosp & Electr Syst Soc AB The finite element model was used to determine the surface figure of membrane mirrors. The Poisson's ratio of the membrane was varied to determine the most desirable materials. It was found that materials with a Poisson's ratio of 0.45 or greater are desirable, Membranes mirrors alone are poor imaging surfaces, and the effects of radial boundary displacement are investigated. It was found that radial boundary displacement can reduce the rms wavefront error of a 42 inch diameter f/1,9 mirror by 78,7%. A 42 inch diameter f/1,06 membrane mirror would have the rms wavefront error reduced by 65,6%. The primary on-axis and off-axis aberration was found to be 3(rd) order spherical aberration for all f-numbers and at all radial displacements. C1 USAF, Res Lab, VSSS, AFRL, Kirtland AFB, NM 87117 USA. RP Peters, KW (reprint author), USAF, Res Lab, VSSS, AFRL, 3550 Aberdeen Ave SE, Kirtland AFB, NM 87117 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4311-5 PY 1998 BP 47 EP 53 PG 7 WC Engineering, Aerospace; Remote Sensing SC Engineering; Remote Sensing GA BL20F UT WOS:000074664900005 ER PT B AU Das, A Obal, MW AF Das, A Obal, MW GP IEEE TI Revolutionary satellite structural systems technology: A vision for the future SO 1998 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOL 2 LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 21-28, 1998 CL ASPEN, CO SP IEEE, Aerosp & Electr Syst Soc AB A number of revolutionary spacecraft structures and control concepts are currently being developed, which when successfully implemented will dramatically change the way future space systems are designed and developed. Many of these concepts will offer new challenges to the designers of the spacecraft structures and control systems. Some of the concepts being explored are: (i) Ultralight Precision Deployable Systems. Revolutionary concepts for compact, lightweight, deployable precision reflectors based on recent breakthroughs in ultralight optical quality mirrors and precision mechanisms. (ii) Multifunctional Structures Satellite. Satellite bus design concepts using multifunctional structures (MFS) that promise to reduce the bus weight by an order of magnitude as well as the fabrication, integration, and launch costs. (iii) Lightweight Flexible Solar Array Systems. To meet the ever-demanding space power requirements at low weight, ultra-lightweight solar array concepts using advances in smart materials, multifunctional structures, and thin film photovoltaics promise up to a factor of five improvement over current technology. (iv) Launch Vehicle Payload Isolation. Passive and active isolation of the payload from the launch environment providing innovative approaches for spacecraft design, integration, test and launch survivability. These revolutionary concepts are explored in the context of their impact on the future design of spacecraft. C1 USAF, Res Lab, Space Technol Integrat & Demonstrat Div, Space Vehicles Directorate, Kirtland AFB, NM 87117 USA. RP Das, A (reprint author), USAF, Res Lab, Space Technol Integrat & Demonstrat Div, Space Vehicles Directorate, Kirtland AFB, NM 87117 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4311-5 PY 1998 BP 57 EP 67 PG 11 WC Engineering, Aerospace; Remote Sensing SC Engineering; Remote Sensing GA BL20F UT WOS:000074664900006 ER PT B AU Huybrechts, S Griffin, S AF Huybrechts, S Griffin, S GP IEEE TI Ultra lightweight structures for deployed optics SO 1998 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOL 2 LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 21-28, 1998 CL ASPEN, CO SP IEEE, Aerosp & Electr Syst Soc AB Future space missions, such as acquisition of high-resolution images in visible or near-visible wavelengths for space surveillance, target identification, and astronomy, require the deployment of space-based telescopes with large (greater than 4 m) effective apertures and with surface accuracy of better than 0.1 micron RMS. Current systems are limited not only by the physical size of the launch vehicle shroud, but also by the quality and alignment of the system after incurring stresses induced by launch. A large, lightweight, durable space telescope using precision deployable structures offers the potential for breakthroughs in high-resolution image acquisition. The Air Force Research Laboratory Space Vehicle Technologies Division, in conjunction with Aeronautical and Astronautical Engineering Department at Stanford University, has been doing research into a new structural configuration fabricated using the newly developed Tooling Reinforced Grid (TRIG) process. These innovative lightweight TRIG structures are extremely stiff and easy to manufacture. Additionally, TRIG structures can be several times lighter than traditional composite structures for stiffness-controlled applications. The first full-scale TRIO structure, with accompanying deployment structure/hardware, was recently fabricated as part of a precision-deployed optical boom experiment. The objective of this experiment was to study deployment accuracy and stability. In this paper, an overview of this experiment is presented from a deployment and structural point of view. C1 USAF, Res Lab, Space Vehicle Technol Div, Kirtland AFB, NM 87117 USA. RP Huybrechts, S (reprint author), USAF, Res Lab, Space Vehicle Technol Div, 3550 Aberdeen Ave SE, Kirtland AFB, NM 87117 USA. NR 0 TC 0 Z9 0 U1 1 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4311-5 PY 1998 BP 83 EP 88 PG 6 WC Engineering, Aerospace; Remote Sensing SC Engineering; Remote Sensing GA BL20F UT WOS:000074664900008 ER PT B AU Pleimann, ME AF Pleimann, ME GP IEEE TI Lightweight meter class optics for deployable optical arrays SO 1998 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOL 2 LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 21-28, 1998 CL ASPEN, CO SP IEEE, Aerosp & Electr Syst Soc AB Next generation space-based imaging systems (> 4 meters) will require high resolution, timely imagery without substantially adding to system mass or cost. Locating tactical targets from high orbits that provide synoptic coverage requires large aperture imaging. The need for large aperture imaging systems pushes fairing volumetric constraints and launch mass constraints. To satisfy this need for large aperture optics, deployable lightweight optical arrays are required. The Space Vehicles Directorate of the Air Force Research Laboratory (AFRL/VS) has pooled its resources in an effort to enable space-based imaging systems at a reduced payload mass. Currently, AFRL/VS is working on a ground demonstration of lightweight meter class optics (UltraLITE program). The ground demonstration test bed includes a full scale deployable precision structure integrated with an optical-mechanical control system. A lightweight optical array flight experiment is being proposed as a follow-on. To support this initiative, AFRL is investing in two high payoff structures technologies: lightweight support structure for deployed optics and ultralight composite mirrors. The goal of the composite mirror program is to develop subscale lightweight (area densities: 5-8 kg/m(2)) mirrors with residual figure errors of lambda/40 rms and wavefront errors of lambda/20 rms. These subscale ground demonstration mirrors are to operate in the visible spectrum (650 nm). A composite fixed third surface mirror and a Continuous Fiber Reinforced Ceramic (CFRC) Silicon Carbide (SiC) mirror are being considered as possible candidates for future ground and flight demonstrations of lightweight mirrors. These technologies help to satisfy the requirement of deployable lightweight optical arrays. By leveraging recent advances in several technology areas including adaptive optics, advanced composites and autonomous control, the AFRL hopes to enable the next generation of low-cost, deployable, lightweight, space-based imaging systems. C1 USAF, Res Lab, Kirtland AFB, NM 87117 USA. RP Pleimann, ME (reprint author), USAF, Res Lab, 3550 Aberdeen Ave SE, Kirtland AFB, NM 87117 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4311-5 PY 1998 BP 89 EP 95 PG 7 WC Engineering, Aerospace; Remote Sensing SC Engineering; Remote Sensing GA BL20F UT WOS:000074664900009 ER PT B AU Leitner, J Calise, A Prasad, JVR AF Leitner, J Calise, A Prasad, JVR GP IEEE TI A full authority helicopter adaptive neuro-controller SO 1998 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOL 2 LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 21-28, 1998 CL ASPEN, CO SP IEEE, Aerosp & Electr Syst Soc AB This paper treats the development of a full authority, six degree of freedom controller for rotorcraft which provides autonomous, high performance, robust tracking of a specified trajectory. The nominal controller is a two time scale input-output-linearizing controller which exploits the well known nonlinearities in the equations of motion, but ignores the variations in the aerodynamically varying quantities. The nominal controller is enhanced with a simple two layer adaptive neural network which accommodates for the variations in the dynamics and guarantees ultimate boundedness of the tracking errors in closed loop. Simulation results are presented employing a high fidelity simulation for the Apache helicopter which has been validated at several flight conditions against flight test data. C1 USAF, Res Lab, Kirtland AFB, NM 87117 USA. RP Leitner, J (reprint author), USAF, Res Lab, 3550 Aberdeen Ave SE, Kirtland AFB, NM 87117 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4311-5 PY 1998 BP 117 EP 126 PG 10 WC Engineering, Aerospace; Remote Sensing SC Engineering; Remote Sensing GA BL20F UT WOS:000074664900011 ER PT B AU Denoyer, K Leitner, J AF Denoyer, K Leitner, J GP IEEE TI Autonomous neural control for the UltraLITE Phase I test article SO 1998 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOL 2 LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 21-28, 1998 CL ASPEN, CO SP IEEE, Aerosp & Electr Syst Soc AB This paper presents preliminary numerical simulation results for autonomous neural control of the Ultra-Lightweight Imaging Technology Experiments (UltraLITE) Phase I test article. The UltraLITE Phase I test article is a precision deployable structure currently under development at the United States Air Force Research Laboratory (AFRL). Its purpose is to examine control and hardware integration issues related to large deployable sparse optical array spacecraft systems. In this paper, a multi-stage control architecture is examined which incorporates artificial neural networks for model inversion tracking control. C1 USAF, Res Lab, VS, AFRL, Kirtland AFB, NM 87117 USA. RP Denoyer, K (reprint author), USAF, Res Lab, VS, AFRL, 3550 Aberdeen Ave SE, Kirtland AFB, NM 87117 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4311-5 PY 1998 BP 127 EP 132 PG 6 WC Engineering, Aerospace; Remote Sensing SC Engineering; Remote Sensing GA BL20F UT WOS:000074664900012 ER PT B AU Davis, TM Tomlinson, BJ AF Davis, TM Tomlinson, BJ GP IEEE TI An overview of Air Force Research Laboratory cryogenic technology development programs SO 1998 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOL 2 LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 21-28, 1998 CL ASPEN, CO SP IEEE, Aerosp & Electr Syst Soc AB This paper presents an overview of the cryogenic refrigerator and cryogenic integration programs in development and characterization under the Cryogenic Technologies Group, Space Vehicles Directorate of the Air Force Research Laboratory (AFRL). The vision statement for the Air Force Research Laboratory Cryogenic Technologies Group is to support the space community as the center of excellence for developing and transitioning space cryogenic thermal management technologies. The primary customers for the AFRL cryogenic technology development programs are BMDO (Ballistic Missile Defense Organization), the USAF SBIRS (Space Based Infrared) Low program office, and DoD space surveillance programs. This paper will describe a variety of Stirling, pulse tube, Reverse Brayton, Joule-Thomson, and Sorption cycle cryocoolers currently under development to meet current and future Air Force and DoD requirements. The AFRL customer single stage cooling requirements at 10K, 35 K, 60 K, 150 K, and multi-stage cooling requirements at 35/60 K are addressed. In order to meet these various requirements, the AFRL Cryogenic Technologies Group is pursuing various strategic cryocooler and cryogenic integration options. The Air Force Research Laboratory is also developing several advanced cryogenic integration technologies that will result in the reduction in current cryogenic system integration penalties and design time. These technologies include the continued development of the Cryogenic Systems Integration Model (CSIM), 60 K and 100 K thermal storage units and heat pipes, cryogenic straps, thermal switches, and development of an Integrated Lightweight Cryogenic Bus (CRYOBUS). C1 USAF, Res Lab, Kirtland AFB, NM 87117 USA. RP Davis, TM (reprint author), USAF, Res Lab, Bldg 30117 Manzano, Kirtland AFB, NM 87117 USA. NR 0 TC 0 Z9 0 U1 1 U2 4 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4311-5 PY 1998 BP 189 EP 198 PG 10 WC Engineering, Aerospace; Remote Sensing SC Engineering; Remote Sensing GA BL20F UT WOS:000074664900019 ER PT B AU Aeby, CA AF Aeby, CA GP IEEE TI Space systems survivability - the protection environment SO 1998 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOL 2 LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 21-28, 1998 CL ASPEN, CO SP IEEE, Aerosp & Electr Syst Soc AB The US military, civilian agencies, and commercial sectors of our economy are becoming increasingly dependent on space systems and their unique capabilities. The aspects of space systems which lend themselves to a concept of Global Virtual Presence also create requirements and technological challenges for protecting the space assets and assuring their operation in the presence of the natural and man-made space environments which can potentially degrade system performance or cause lifetime-limiting damage. This paper will discuss the "protection environment", the process and methods used for determining protection needs, and the framework employed to identify potential protection solutions. The emphasis will be on the orbital segments of space systems. The determination of the protection needs for a particular space asset is governed by: (1) The importance of the product delivered by the "system" to an end user and the criticality of the particular asset to the generation and delivery process; (2) the characteristics of the operational environment within which the space asset functions and performs its mission; and (3) the interactions of the spacecraft with the environment and the potential for unacceptable performance degradation or adverse mission impact. The mission of the spacecraft and the design of the payload(s) and bus will define the technologies important to assessing environment and component interactions, attendant susceptibilities, and potential performance degradation. The characteristics of the operational environment (natural and man-made) with regard to intensity, temporal characteristics, orbital dependence, and other critical parameters will determine the nature and "severity" of the interactions, and the design-dependent coupling of effects throughout the spacecraft. Based on the determination of protection needs, the options for providing cost-effective, performance-compatible protection solutions are evaluated. Typically, the options fall into the broad categories of avoiding and/or reducing exposure of the mission-critical components to the environment, or withstanding/operating through the environment. Protection options include "system" architectures, constellation sizing and orbit configurations, responsive and adaptive solutions, and hardware/software adaptations. Some of the protection solutions for environments which adversely impact spacecraft performance are dependent on "sensing" the presence and characteristics of the environment, whether natural or man-made. Protection needs for military spacecraft can include the additional burden of hostile threats designed to deliberately degrade, damage, or otherwise limit the military effectiveness of the system. Hence, additional protection options and approaches beyond those employed for civil/commercial spacecraft are required. C1 USAF, Res Lab, Kirtland AFB, NM 87117 USA. RP Aeby, CA (reprint author), USAF, Res Lab, 3550 Aberdeen Ave SE, Kirtland AFB, NM 87117 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4311-5 PY 1998 BP 201 EP 205 PG 5 WC Engineering, Aerospace; Remote Sensing SC Engineering; Remote Sensing GA BL20F UT WOS:000074664900020 ER PT B AU Hilland, DH Phipps, GS Jingle, CM Newton, G AF Hilland, DH Phipps, GS Jingle, CM Newton, G GP IEEE TI Satellite threat warning and attack reporting SO 1998 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOL 2 LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 21-28, 1998 CL ASPEN, CO SP IEEE, Aerosp & Electr Syst Soc AB The Air Force Research Laboratory's Satellite Threat Warning and Attack Reporting (STW/AR) program will provide technologies for advanced threat warning and reporting of radio frequency (RF) and laser threats. The STW/AR program objectives are: (1) Develop cost-effective technologies to detect, identify, locate, characterize, and report attacks or interference against U. S. and Allied satellites. (2) Demonstrate innovative, lightweight, low-power, RF and laser sensors. The program focuses on the demonstration of RF and laser sensors. The RF sensor effort includes the investigation of interferometric antenna arrays, multi-arm spiral and butler matrix antennas, wideband receivers, adaptive processors, and improved processing algorithms. The laser sensor effort includes the investigation of alternative detectors, broadband grating and optical designs, active pixel sensing, and improved processing algorithms. An objective for both sensors is to miniaturize the sensor packages to reduce the weight and power requirements. The most promising technologies will be demonstrated on two space experiments which will include the participation of Defense Department personnel involved with spacecraft operations. The ultimate goal is to deploy multiple STW/AR sensors as ride along payloads on high value spacecraft. An RF space experiment will be flown on the Air Force Research Laboratory's MightySat II satellite in a low earth orbit around the year 2001. This light weight, low power, RF payload will monitor frequencies covering typical satellite communications. The sensor will have the capability to gee-locate RF sources of interest. Due to the short physical span of the RF interferometers, the geo-location algorithm will utilize satellite motion to resolve ambiguities. The laser technology program will demonstrate various laser sensors on the ground with eventual demonstration in space. Linear arrays, to detect and gee-locate both continuous wave and pulsed laser sources, are being investigated. A visible and infrared subassembly is used to cover the required wavelengths while maintaining the needed sensitivity and false alarm rejection. In addition, algorithm development efforts are also underway to support the laser characterization and gee-location functions. C1 USAF, Res Lab, VS, AFRL, Kirtland AFB, NM 87117 USA. RP Hilland, DH (reprint author), USAF, Res Lab, VS, AFRL, Kirtland AFB, NM 87117 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4311-5 PY 1998 BP 207 EP 217 PG 11 WC Engineering, Aerospace; Remote Sensing SC Engineering; Remote Sensing GA BL20F UT WOS:000074664900021 ER PT B AU Nedeau, J King, D Lanza, D Hunt, K Byington, L AF Nedeau, J King, D Lanza, D Hunt, K Byington, L GP IEEE TI 32-bit radiation-hardened computers for space SO 1998 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOL 2 LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 21-28, 1998 CL ASPEN, CO SP IEEE, Aerosp & Electr Syst Soc AB Over the past 11 years, the Air Force Research Laboratory (AFRL), Phillips Research Center (formerly Phillips Laboratory) has championed the development of microprocessors and computers for United States Air Force (USAF) space and strategic missile application. The latest of these programs, the Advanced Technology Insertion Module (ATIM), is currently scheduled for completion at the end of 1997. ATIM is developing two single-board computers based on 32-bit reduced instruction set computer (RISC) processors. ATIM technology is baselined in the majority of today's Department of Defense (DoD), NASA, including Mars Pathfinder, and commercial satellite systems. The Improved Space Computer Program (ISCP) is envisioned as the next-generation space computer: merging advanced technologies and architectures to meet the high-performance, on-board processing needs for 21(st) century DoD, NASA, and commercial satellites. ISCP is a three pronged effort to evaluate evolving mission requirements, develop a commercial-heritage architecture, and integrate emerging technologies for space applications. These three areas are: the Phase I Concept/Architecture Studies, the Improved Space Architecture Concept (ISAC), and the technology development efforts. ISAC lays out a sequential approach aimed at developing and demonstrating the potential for on-board, satellite processing. The combined serial and parallel development activities will prove that commercial-heritage architectures and technologies can reduce the development time and costs associated with building the next-generation spacecraft. C1 USAF, Phillips Lab, VTME, Kirtland AFB, NM 87117 USA. RP Nedeau, J (reprint author), USAF, Phillips Lab, VTME, 3550 Aberdeen Ave SE, Kirtland AFB, NM 87117 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4311-5 PY 1998 BP 241 EP 253 PG 13 WC Engineering, Aerospace; Remote Sensing SC Engineering; Remote Sensing GA BL20F UT WOS:000074664900023 ER PT B AU Christensen, MK Weber, G Seelos, M Moua, C Gillen, S AF Christensen, MK Weber, G Seelos, M Moua, C Gillen, S GP IEEE TI F-16 Database Terrain Cueing - An investigation of display handling qualities SO 1998 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOL. 3 LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 21-28, 1998 CL ASPEN, CO SP IEEE, Aerosp & Electr Syst Soc AB Database Terrain Cueing (DBTC) is one of five functions in the new Digital Terrain System (DTS) to be integrated into all F-16s including those flown by the European Participating Air Forces. The Terrain Referenced Navigation (TRN) function of the DTS determines aircraft position relative to a stored digital flight map based upon digital terrain elevation data. The DBTC function provides a vertical steering guidance cue displayed as a box in the heads up display. By maintaining the flight path marker in this box, a pilot could fly at a preset terrain clearance height. The DBTC function demonstrated military utility by serving as a cue to aid the pilot in terrain masking under low visibility conditions. This system was particularly useful when flying with night vision goggles. C1 USAF, Edwards AFB, CA 93523 USA. RP Christensen, MK (reprint author), USAF, Edwards AFB, CA 93523 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4311-5 PY 1998 BP 51 EP 58 PG 8 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Remote Sensing SC Engineering; Remote Sensing GA BL20G UT WOS:000074665000005 ER PT B AU Hill, DE Wallace, KM AF Hill, DE Wallace, KM GP IEEE TI Differential GPS improves domestic and international flight test and evaluation applications SO 1998 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOL. 3 LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 21-28, 1998 CL ASPEN, CO SP IEEE, Aerosp & Electr Syst Soc AB Advanced airborne sensor technology in support of Non-Cooperative Target identification (NCTI) programs has been the subject of ongoing programs at Wright Laboratory for several years. To ensure valid experimental results, researchers recognized the need to control as many variables as possible during airborne sensor research and development activities. Ground-based multilateration systems such as the Air Combat Maneuvering Instrumentation (ACMI), Tactical Aircrew Combat Training System (TACTS), and Red Flag Measurement and Debriefing System (RFMDS) have provided data to support these tests; however, because these systems require large amounts of system hardware (microwave towers, downlink stations, etc.) located at permanent installations, the geographical area available for testing is limited. As a result, overall system usefulness has been less than desired. C1 USAF, Wright Lab, Avion Directorate, Wright Patterson AFB, OH 45433 USA. RP Hill, DE (reprint author), USAF, Wright Lab, Avion Directorate, 2241 Avion Circle, Wright Patterson AFB, OH 45433 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4311-5 PY 1998 BP 209 EP 215 PG 7 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Remote Sensing SC Engineering; Remote Sensing GA BL20G UT WOS:000074665000019 ER PT B AU Rich, M Stoyanof, M Glaister, D AF Rich, M Stoyanof, M Glaister, D GP IEEE TI Trade studies on IR gimbaled optics cooling technologies SO 1998 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOL 5 LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 21-28, 1998 CL ASPEN, CO SP IEEE, Aerosp & Electr Syst Soc AB As advanced space based IR target acquisition and tracking systems continue to mature, the necessity to remove heat across a two-axis gimbal joint has become a critical requirement. Heat loads and dun, cycles continue to increase, making current solutions no longer tenable. The Thermal Bus Focused Technology Area, a member of Air Force Research Laboratories (AFRL) under the Space Vehicles Directorate, conducted a system level trade study of the different methods and technologies under consideration. C1 USAF, Res Labs, Kirtland AFB, NM 87117 USA. RP Rich, M (reprint author), USAF, Res Labs, Bldg 30117 Manzano, Kirtland AFB, NM 87117 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4311-5 PY 1998 BP 255 EP 267 PG 13 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Remote Sensing; Optics SC Engineering; Remote Sensing; Optics GA BL20J UT WOS:000074665200026 ER PT B AU Kirkland, LV Wright, RG AF Kirkland, LV Wright, RG GP IEEE IEEE TI Stabilizing the GO-PATH by evaluating DTIF files for a "don't care status" SO 1998 IEEE AUTOTESTCON PROCEEDINGS - IEEE SYSTEMS READINESS TECHNOLOGY CONFERENCE LA English DT Proceedings Paper CT AUTOTESTCON IEEE Systems Readiness Technology Conference on Test Technology for the 21st Century CY AUG 24-27, 1998 CL SALT LAKE CITY, UT SP IEEE, Aerosp & Electr Syst Soc, Instrumentat & Measurement Soc, IEEE, Los Angeles Council AB The Digital Test Interchange Format (IEEE P1445 - DTIF) is a mechanism for logic data interchange between the automatic test system (ATS) and the unit under test (UUT). This paper will describe conflicts between theoretical logic and actual logic data that may occur periodically in test programs using DTIF format, causing a good UUT to fail when tested. Many of the factors associated with these types of problems will be addressed, a number of which are not illustrative of circuit operation. The paper will begin with a discussion of the variability of UUT functionality on a specific ATE based on factors like: impedance, timing, windows, and drive potential. This variability causes sporadic or intermittent measurements such that, given the same stimulus, they sometimes pass and sometimes they fail. An example of this variability is that of power supply capacitance between the ATE and UUT. After compensating fo, or correcting these variable UUT functionality factors, a measurement may still continue to be sporadic. Such a failure that cannot be stabilized causes the associated tests to become useless and causes considerable testing problems ranging from wasted staff, time, and material resources. In particular, needless UUT repair actions that do not alter test results cause excessive wear on the UUT and significantly reduces its useful life. Sporadic failures must be corrected and the test sequences must be stable and repeatable to effect proper repair and reduce the frustration level of the repair technician. The mechanism to remove sporadic failures from the test program when normal procedures fail to isolate the problem will be presented on the basis of evaluating the ability to detect such tests and to alter their characteristics based upon well-defined criteria. This will include a discussion of the specific criteria that must exist and the methods that should be used to alter the appropriate files to eliminate sporadic failures. The paper will conclude with an evaluation of the DTIF files with respect to their applicability to the fault detection and functionality of the UUT. C1 USAF, TISAC, Larry V Kirkland OO ALC, Hill AFB, UT 84056 USA. RP Kirkland, LV (reprint author), USAF, TISAC, Larry V Kirkland OO ALC, 7278 4th St, Hill AFB, UT 84056 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4420-0 PY 1998 BP 1 EP 5 DI 10.1109/AUTEST.1998.713412 PG 5 WC Engineering, Aerospace; Engineering, Multidisciplinary; Engineering, Electrical & Electronic; Instruments & Instrumentation; Medical Informatics; Transportation SC Engineering; Instruments & Instrumentation; Medical Informatics; Transportation GA BL72A UT WOS:000076427600001 ER PT B AU Head, M AF Head, M GP IEEE IEEE TI Data acquisition of mechanical devices a new way to think SO 1998 IEEE AUTOTESTCON PROCEEDINGS - IEEE SYSTEMS READINESS TECHNOLOGY CONFERENCE LA English DT Proceedings Paper CT AUTOTESTCON IEEE Systems Readiness Technology Conference on Test Technology for the 21st Century CY AUG 24-27, 1998 CL SALT LAKE CITY, UT SP IEEE, Aerosp & Electr Syst Soc, Instrumentat & Measurement Soc, IEEE, Los Angeles Council AB In today's environment of high speed personal computers and laptops, acquisition system design has remained unaffected. Most systems use interface electronics to convert a mechanical signal representing either positional movement or rate of change into an analog or digital format. This interface is a series of conversions from a complicated electrical signal into a simple one and is done outside the computer to simplify software. With the speed of today's systems, this task is better done in software for many applications. In the world of jet engine testing, sensors on the engine are used to measure parameters while testing the engine; there is the common Resistance Temperature Device (RTD) and thermocouple, but there are also syncros/resolvers, vibration transducers, flowmeters and tachometers. Current state-of-the-art testers rely on expensive electronics to convert these latter signals into analog or digital format, to then be processed through the computer into calibrated and scaled units for display and calculations. These transducers specifically could be measured with simple analog channels and mathematically processed in software, allowing a much simplified and less expensive system both in terms of total system hardware as well as software. Topics covered by this paper will be discussed by individual sensor type. The mathematics involved and LabVIEW methods of measurement will be detailed, including a discussion of the methods used to apply this way of thinking to other types of transducers. C1 San Antonio Air Logist Ctr, SA, ALC, TIS, Kelly AFB, TX 78241 USA. RP Head, M (reprint author), San Antonio Air Logist Ctr, SA, ALC, TIS, Kelly AFB, TX 78241 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4420-0 PY 1998 BP 479 EP 485 DI 10.1109/AUTEST.1998.713488 PG 7 WC Engineering, Aerospace; Engineering, Multidisciplinary; Engineering, Electrical & Electronic; Instruments & Instrumentation; Medical Informatics; Transportation SC Engineering; Instruments & Instrumentation; Medical Informatics; Transportation GA BL72A UT WOS:000076427600076 ER PT B AU Allred, LG AF Allred, LG GP IEEE IEEE TI Using infrared thermography to detect age degradation in EPROM chips SO 1998 IEEE AUTOTESTCON PROCEEDINGS - IEEE SYSTEMS READINESS TECHNOLOGY CONFERENCE LA English DT Proceedings Paper CT AUTOTESTCON IEEE Systems Readiness Technology Conference on Test Technology for the 21st Century CY AUG 24-27, 1998 CL SALT LAKE CITY, UT SP IEEE, Aerosp & Electr Syst Soc, Instrumentat & Measurement Soc, IEEE, Los Angeles Council AB Dozens of circuit cards (about 5% of the total) failed to function after a recent upgrade of the digital Plight Control Computer (FLCC), even though all of these cards operated correctly before the modifications. The shop called for the use of the infrared camera to assist in diagnosing and repairing these cards. What the Neural Radiant Energy Detection (NREDS) found was faulty and marginal chips. Of particular interest was the presence of degraded EPROM chips on the Program Memory (PM) cards. While it is known that EPROMs have a limited life cycle (in terms of number of total recordings), the failure has been further characterized. Thermography provides a quantification of the degradation in thermal performance as the EPROMs are reused. When the heat rates exceed a given value, the EPROM chips will not accept a program. Some of the failed chips exhibited enormous heat rates. What is clear from these results is that infrared thermography can he used to identify degrading EPROM chips for replacement before failures become immanent. C1 TIS, Software Engn Div, Ogden Air Logist Ctr, Hill AFB, UT 84056 USA. RP Allred, LG (reprint author), TIS, Software Engn Div, Ogden Air Logist Ctr, Hill AFB, UT 84056 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4420-0 PY 1998 BP 546 EP 551 DI 10.1109/AUTEST.1998.713496 PG 6 WC Engineering, Aerospace; Engineering, Multidisciplinary; Engineering, Electrical & Electronic; Instruments & Instrumentation; Medical Informatics; Transportation SC Engineering; Instruments & Instrumentation; Medical Informatics; Transportation GA BL72A UT WOS:000076427600083 ER PT B AU Kirkland, LV AF Kirkland, LV GP IEEE IEEE TI Techniques and applications for NEURAL NETWORKS "An air force perspective" SO 1998 IEEE AUTOTESTCON PROCEEDINGS - IEEE SYSTEMS READINESS TECHNOLOGY CONFERENCE LA English DT Proceedings Paper CT AUTOTESTCON IEEE Systems Readiness Technology Conference on Test Technology for the 21st Century CY AUG 24-27, 1998 CL SALT LAKE CITY, UT SP IEEE, Aerosp & Electr Syst Soc, Instrumentat & Measurement Soc, IEEE, Los Angeles Council AB This paper describes the use of neural networks in combination with algorithmic test programs to aid in improving test efficiency and accuracy, especially in test situations where "bad actor" test programs exist that have difficulty in detecting and isolating Unit Under Test (UUT) failures. C1 OO ALC TISAC, Hill AFB, UT 84056 USA. RP Kirkland, LV (reprint author), OO ALC TISAC, 7278 4th St, Hill AFB, UT 84056 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4420-0 PY 1998 BP 580 EP 583 DI 10.1109/AUTEST.1998.713500 PG 4 WC Engineering, Aerospace; Engineering, Multidisciplinary; Engineering, Electrical & Electronic; Instruments & Instrumentation; Medical Informatics; Transportation SC Engineering; Instruments & Instrumentation; Medical Informatics; Transportation GA BL72A UT WOS:000076427600087 ER PT B AU McNeely, JA Cento, SJ AF McNeely, JA Cento, SJ GP IEEE IEEE TI Multiple data base integration & update (MDBI&U) SO 1998 IEEE INFORMATION TECHNOLOGY CONFERENCE, PROCEEDINGS LA English DT Proceedings Paper CT 1998 IEEE Information Technology Conference on Information Environment for the Future CY SEP 01-03, 1998 CL SYRACUSE, NY SP AF Res Lab/Informat Directorate & Informat Inst, ANDRO Consulting Serv, IIT Res Inst, ITT Syst Corp, NY State Technol Enterprise Corp, Synectics Corp AB The Multiple Data Base Integration and Update (MDBI&U) effort began in October 1995 and is scheduled for completion in September 1998. The Air Force Research Laboratory (ARFL) Information Fusion and Engineering Branch (IFEA), in Rome, NY is the Government sponsor for this Advanced Technology Demonstration (ATD) effort. Northrop Grumman Corporation (NGC) in Bethpage, NY is the prime contractor. MDBI&U automatically maintains the timeliness and consistency of a geospatial baseline feature data base using all available update source materials within Air Force channels : (1) formatted text from the field and DIA's Modernized Intelligent Data Base (MIDB), (2) NIMA aeronautical products (i.e., ECHUM, DAFIF, etc.), and (3) information extracted from digital imagery and terrain. Today's digital geospatial data sources differ with respect to scale/resolution, accuracy, extent of coverage, content, attribution, format, and/or media. Our objective is to automatically reconcile and integrate these multiple disparate geospatial sources to produce a Unified Vector Data Base (UVDB). This 'value-added' geospatial foundation provides 'combat ready' feature data to support predictive intelligence and proactive engagement activities by establishing and maintaining a common, consistent, and current representation of the battlespace. C1 USAF, Res Lab, Informat Fus Branch IFEA, Griffiss AFB, NY 13441 USA. RP McNeely, JA (reprint author), USAF, Res Lab, Informat Fus Branch IFEA, Rome Site,32 Brooks Rd, Griffiss AFB, NY 13441 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-9914-5 PY 1998 BP 19 EP 22 DI 10.1109/IT.1998.713372 PG 4 WC Computer Science, Information Systems; Computer Science, Interdisciplinary Applications SC Computer Science GA BL72L UT WOS:000076450700006 ER PT B AU Sisti, AF AF Sisti, AF GP IEEE IEEE TI Enabling technologies for simulation science SO 1998 IEEE INFORMATION TECHNOLOGY CONFERENCE, PROCEEDINGS LA English DT Proceedings Paper CT 1998 IEEE Information Technology Conference on Information Environment for the Future CY SEP 01-03, 1998 CL SYRACUSE, NY SP AF Res Lab/Informat Directorate & Informat Inst, ANDRO Consulting Serv, IIT Res Inst, ITT Syst Corp, NY State Technol Enterprise Corp, Synectics Corp AB While there has been much attention paid to Modeling and Simulation as it relates to specific application areas, little has been done to address those broad technology areas that enhance, and in some cases, revolutionize the way we configure, execute and analyze the results of simulations. Recognizing that our simulation capabilities are expected to keep pace with ever-changing demands made of them, we differentiate between those technologies that are evolutionary in nature - that is, where existing tools and techniques can undergo incremental improvements in order to address consumer requirements and those of a revolutionary nature; which address those requirements for which no current technology solutions exist. C1 USAF, Res Lab, IFSB, Rome, NY 13441 USA. RP Sisti, AF (reprint author), USAF, Res Lab, IFSB, 525 Brooks Rd, Rome, NY 13441 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-9914-5 PY 1998 BP 33 EP 36 DI 10.1109/IT.1998.713375 PG 4 WC Computer Science, Information Systems; Computer Science, Interdisciplinary Applications SC Computer Science GA BL72L UT WOS:000076450700009 ER PT B AU Pflug, DR AF Pflug, DR GP IEEE IEEE TI Model based parameter estimation as a model abstraction technique SO 1998 IEEE INFORMATION TECHNOLOGY CONFERENCE, PROCEEDINGS LA English DT Proceedings Paper CT 1998 IEEE Information Technology Conference on Information Environment for the Future CY SEP 01-03, 1998 CL SYRACUSE, NY SP AF Res Lab/Informat Directorate & Informat Inst, ANDRO Consulting Serv, IIT Res Inst, ITT Syst Corp, NY State Technol Enterprise Corp, Synectics Corp AB In this paper it is demonstrated that the technique of Model Based Parameter Estimation (MBPE), specifically Cauchy's Method, can be used in the frequency domain to extrapolate/interpolate a narrowband set of system data or information to a broadband set of data or information. The information can be either computed data or measured experimental data over a frequency band. For computed data the sampled values of the function and a few derivative values are used to reconstruct the function. For measured data only sampled values of the function are used as derivative values are too noisy. Cauchy's method is based on applying the principle of analytic continuation to a complex, hard to specify function, analytic except at isolated poles, that represents the frequency domain property of interest. Such a function can be represented by a ratio of two polynomials, a reduced order model, which can be considered to be a variant of model abstraction [3]. A procedure is outlined for determining the order of the polynomials and their coefficients using the methods of Singular Value Decomposition (SVD) and Least Squares. The method is applied to a selected set of frequency domain problems to illustrate the accuracy and versatility of the method. C1 USAF, Res Lab, IFSB, Rome, NY 13441 USA. RP Pflug, DR (reprint author), USAF, Res Lab, IFSB, 525 Brooks Rd, Rome, NY 13441 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-9914-5 PY 1998 BP 37 EP 40 DI 10.1109/IT.1998.713376 PG 4 WC Computer Science, Information Systems; Computer Science, Interdisciplinary Applications SC Computer Science GA BL72L UT WOS:000076450700010 ER PT B AU Ratazzi, EP Ryan, JP AF Ratazzi, EP Ryan, JP GP IEEE IEEE TI Ultra Comm: The next generation of multi-band, multi-mode communication systems SO 1998 IEEE INFORMATION TECHNOLOGY CONFERENCE, PROCEEDINGS LA English DT Meeting Abstract CT 1998 IEEE Information Technology Conference on Information Environment for the Future CY SEP 01-03, 1998 CL SYRACUSE, NY SP AF Res Lab/Informat Directorate & Informat Inst, ANDRO Consulting Serv, IIT Res Inst, ITT Syst Corp, NY State Technol Enterprise Corp, Synectics Corp C1 USAF, Informat Directorate, Griffiss AFB, NY 13441 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-9914-5 PY 1998 BP 173 EP 176 DI 10.1109/IT.1998.713408 PG 4 WC Computer Science, Information Systems; Computer Science, Interdisciplinary Applications SC Computer Science GA BL72L UT WOS:000076450700042 ER PT B AU Van Veldhuizen, DA Sandlin, BS Marmelstein, RE Lamont, GB Terzuoli, AJ AF Van Veldhuizen, DA Sandlin, BS Marmelstein, RE Lamont, GB Terzuoli, AJ GP IEEE TI Finding improved wire-antenna geometries with genetic algorithms SO 1998 IEEE INTERNATIONAL CONFERENCE ON EVOLUTIONARY COMPUTATION - PROCEEDINGS SE IEEE Congress on Evolutionary Computation LA English DT Proceedings Paper CT IEEE International Conference on Evolutionary Computation CY MAY 04-09, 1998 CL ANCHORAGE, AK SP Int Neural Network Soc, IEEE, Neural Networks Council, IEEE, Alaska Sect AB A remote monitoring system's performance is measured largely by its associated antennas' efficacy. Improving antenna performance is not a straightforward process, as many (sometimes conflicting) design trade-offs must be considered. An alternative approach specifies desired antenna properties and then searches for antenna geometries producing those properties. We implement this approach of designing a wire antenna having optimal performance under user-defined adverse conditions by using a genetic algorithm, where fitness of promising designs is analysed using the Numerical Electromagnetics Code (NEC) Version 4.1. Two versions of an integrated GA-NEC code are implemented; both produce geometries showing improvement over current designs. Results for both versions are presented, compared, and discussed. C1 USAF, Inst Technol, Grad Sch Engn, Dept Elect & Comp Engn, Wright Patterson AFB, OH 45433 USA. RP Van Veldhuizen, DA (reprint author), USAF, Inst Technol, Grad Sch Engn, Dept Elect & Comp Engn, Wright Patterson AFB, OH 45433 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4869-9 J9 IEEE C EVOL COMPUTAT PY 1998 BP 102 EP 107 DI 10.1109/ICEC.1998.699330 PG 6 WC Computer Science, Artificial Intelligence; Computer Science, Interdisciplinary Applications; Computer Science, Theory & Methods SC Computer Science GA BL57Z UT WOS:000075926200018 ER PT S AU O'Neil, P Paik, WJ AF O'Neil, P Paik, WJ GP IEEE IEEE IEEE IEEE TI The Chronological information Extraction SyStem (CHESS) SO 1998 IEEE INTERNATIONAL CONFERENCE ON SYSTEMS, MAN, AND CYBERNETICS, VOLS 1-5 SE IEEE INTERNATIONAL CONFERENCE ON SYSTEMS, MAN, AND CYBERNETICS, CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE International Conference on Systems, Man, and Cybernetics - Intelligent Systems for Humans in a Cyberworld (SMC 98) CY OCT 11-14, 1998 CL SAN DIEGO, CA SP IEEE, Syst Man & Cybernet Soc AB The Chronological information Extraction SyStem (CHESS) performs two main functions to provide the user with rich contextual, time-stamped information about relevant people, organizations, countries, or any other named entities. First, it extracts information about named entities and compiles a chronological outline. Second, it acts as a question answering system, allowing the user to find information of interest. In this capacity, the knowledge automatically extracted by CHESS can be examined in different information access modes: 1) as a browser, for information seekers who do not have specific queries; 2) as a question-answering system, for users with specific queries. Information is extracted from free text utilizing natural language processing techniques. CHESS takes advantage of the common practice of writers placing information-rich linguistic constructions in close proximity to named entities. First, the proper name is recognized, and then the surrounding information is used to develop relationships to other names entities. In this manner, concept-relation-concept (CRC) triples are formed and stored in an object database. Complex histories of events in relation to a given named entity are constructed from these CRC triples, utilizing techniques from conceptual graph theory. C1 USAF, Res Lab, Rome, NY 13441 USA. RP O'Neil, P (reprint author), USAF, Res Lab, Rome, NY 13441 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1062-922X BN 0-7803-4778-1 J9 IEEE SYS MAN CYBERN PY 1998 BP 1674 EP 1679 PG 6 WC Computer Science, Cybernetics SC Computer Science GA BL88E UT WOS:000077033700294 ER PT S AU Salerno, JJ AF Salerno, JJ GP IEEE IEEE IEEE IEEE TI Neural networks: Life after training SO 1998 IEEE INTERNATIONAL CONFERENCE ON SYSTEMS, MAN, AND CYBERNETICS, VOLS 1-5 SE IEEE INTERNATIONAL CONFERENCE ON SYSTEMS, MAN, AND CYBERNETICS, CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE International Conference on Systems, Man, and Cybernetics - Intelligent Systems for Humans in a Cyberworld (SMC 98) CY OCT 11-14, 1998 CL SAN DIEGO, CA SP IEEE, Syst Man & Cybernet Soc AB There has been much work done in the use of neural networks to model an existing problem, but little has been done to address what happens after training has been completed and the model must continue to learn new information. How well does the model work on information that it has not seen before? How does it adapt to new information? In this paper we address these issues beginning our discussion with a neural model that has been trained on parsing simple natural language phrases and how well the model can generalize. Based on these results we will then investigate two techniques which attempt to allow the model to "grow" or learn information that it has never before seen. C1 USAF, Res Lab, Rome, NY 13441 USA. RP Salerno, JJ (reprint author), USAF, Res Lab, Rome Site, Rome, NY 13441 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1062-922X BN 0-7803-4778-1 J9 IEEE SYS MAN CYBERN PY 1998 BP 1680 EP 1685 PG 6 WC Computer Science, Cybernetics SC Computer Science GA BL88E UT WOS:000077033700295 ER PT S AU Marmelstein, RE Van Veldhuizen, DA Lamont, GB AF Marmelstein, RE Van Veldhuizen, DA Lamont, GB GP IEEE IEEE IEEE IEEE TI A distributed architecture for an adaptive computer virus immune system SO 1998 IEEE INTERNATIONAL CONFERENCE ON SYSTEMS, MAN, AND CYBERNETICS, VOLS 1-5 SE IEEE INTERNATIONAL CONFERENCE ON SYSTEMS, MAN, AND CYBERNETICS, CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE International Conference on Systems, Man, and Cybernetics - Intelligent Systems for Humans in a Cyberworld (SMC 98) CY OCT 11-14, 1998 CL SAN DIEGO, CA SP IEEE, Syst Man & Cybernet Soc AB Computer viruses are widely recognized as a significant computer threat. The "birth rate" of new viruses is high and increasing due to global connectivity, and technology improvements can accelerate their spread. In response to this threat, some contemporary research efforts are aimed at creating computer virus immune systems (CVIS). A CVIS uses the human immune system as a model for identifying, attacking, and eradicating viruses from computers and networks. This paper analyzes the requirements of such a computer virus immune system and evaluates current approaches with respect to these requirements. Based on this analysis, we propose a distributed architecture for implementing a CVIS. In particular, we discuss how emerging technologies such as evolutionary algorithms (EAs) and intelligent agents (IAs) can be employed to give the CVIS a self-adaption capability for new viral threats. C1 USAF, Inst Technol, Grad Sch Engn, Dept Elect & Comp Engn, Wright Patterson AFB, OH 45433 USA. RP Marmelstein, RE (reprint author), USAF, Inst Technol, Grad Sch Engn, Dept Elect & Comp Engn, Wright Patterson AFB, OH 45433 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1062-922X BN 0-7803-4778-1 J9 IEEE SYS MAN CYBERN PY 1998 BP 3838 EP 3843 PG 6 WC Computer Science, Cybernetics SC Computer Science GA BL88E UT WOS:000077033700667 ER PT B AU Ebel, J Bozada, C Schlesinger, T Cerny, C DeSalvo, G Dettmer, R Gillespie, J Jenkins, T Nakano, K Pettiford, C Quach, T Sewell, J Via, G Welch, R AF Ebel, J Bozada, C Schlesinger, T Cerny, C DeSalvo, G Dettmer, R Gillespie, J Jenkins, T Nakano, K Pettiford, C Quach, T Sewell, J Via, G Welch, R GP IEEE TI Cross-sectional atomic force microscopy of focused ion beam milled devices SO 1998 IEEE INTERNATIONAL RELIABILITY PHYSICS SYMPOSIUM PROCEEDINGS - 36TH ANNUAL LA English DT Proceedings Paper CT 36th Annual IEEE International Reliability Physics Symposium CY MAR 31, 1996-APR 02, 1998 CL RENO, NV SP IEEE Electron Devices Soc, IEEE Reliabil Soc C1 USAF, Res Lab, Av Directorate, Electron Devices Div, Wright Patterson AFB, OH 45433 USA. RP Ebel, J (reprint author), USAF, Res Lab, Av Directorate, Electron Devices Div, Wright Patterson AFB, OH 45433 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4400-6 PY 1998 BP 157 EP 162 DI 10.1109/RELPHY.1998.670475 PG 6 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA BK90C UT WOS:000073835800024 ER PT B AU James, C DiBene, JT AF James, C DiBene, JT GP IEEE IEEE TI The charge density distributions and mutual capacitance of a shielded twisted four-wire transmission line SO 1998 IEEE INTERNATIONAL SYMPOSIUM ON ELECTROMAGNETIC COMPATIBILITY - SYMPOSIUM RECORD, VOLS 1 AND 2 LA English DT Proceedings Paper CT 1998 International Symposium on Electromagnetic Compatibility CY AUG 24-28, 1998 CL DENVER, CO SP IEEE EMS Soc, Rocky Mt Chapter AB In this paper, the authors characterize the capacitance of a shielded twisted four-wire transmission line structure. The procedure used was developed by the author Dr. Craig James, and Dr. John Norgard for the characterization of the shielded twisted pair transmission line, presented at the IEEE 1996 International Symposium on Electromagnetic Compatibility. The characterization is based on the determination of the quasi-static charge density distributions on the conductor surfaces making up the shielded twisted four-wire transmission line. From the determined charges, the electric potential distribution and capacitances are found. The characterization of the four wire structure is significantly different from the pair because some of the symmetry of the pair is lost. C1 USAF, Res Lab, IFTC, Rome, NY 13440 USA. RP James, C (reprint author), USAF, Res Lab, IFTC, Rome, NY 13440 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-5015-4 PY 1998 BP 1156 EP 1160 PG 5 WC Engineering, Electrical & Electronic SC Engineering GA BM59X UT WOS:000079200400215 ER PT B AU Pflug, DR AF Pflug, DR GP IEEE IEEE TI A novel test article for validation of EMC codes for antenna-to-antenna coupling and antenna isolation: The transformable scale aircraft-like model SO 1998 IEEE INTERNATIONAL SYMPOSIUM ON ELECTROMAGNETIC COMPATIBILITY - SYMPOSIUM RECORD, VOLS 1 AND 2 LA English DT Proceedings Paper CT 1998 International Symposium on Electromagnetic Compatibility CY AUG 24-28, 1998 CL DENVER, CO SP IEEE EMS Soc, Rocky Mt Chapter AB A novel all-metal test article, the Transformable Scale Aircraft-Like Model (TSAM) has been constructed recently to obtain measured antenna pattern and isolation data for validating electromagnetic compatibility (EMC) and computational electromagnetics (CEM) analysis codes used to analyze antenna-to-antenna coupling and platform effects on antenna radiation patterns. TSAM makes use of a changeable configuration to identify those parts of the platform that affect the radiation performance and coupling properties of mounted antennas.. All components and antennas are removable allowing TSAM complexity to be modified gradually in stages. As platform complexity changes, the measured data of electromagnetic observables changes correspondingly. Computed results from electromagnetics codes then should track the measured results as the TSAM computer geometry model changes. If they do not then information has been obtained to help identify where in the codes the shortcomings are located. This paper will present and discuss a set of antenna pattern and isolation measurements made on TSAM in the 4-8 GHz. range involving several different TSAM configurations that are useful to validate EMC and CEM codes. The TSAM test article and antenna measurement process will be discussed and the applicability to validating electromagnetics analysis codes will be explained. C1 USAF, Res Lab, Rome, NY 13441 USA. RP Pflug, DR (reprint author), USAF, Res Lab, Rome Res Site,525 Brooks Rd, Rome, NY 13441 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-5015-4 PY 1998 BP 1161 EP 1165 PG 5 WC Engineering, Electrical & Electronic SC Engineering GA BM59X UT WOS:000079200400216 ER PT S AU Lorenzo, J AF Lorenzo, J GP IEEE IEEE TI History and highlights, a chronicle of IPRM SO 1998 INTERNATIONAL CONFERENCE ON INDIUM PHOSPHIDE AND RELATED MATERIALS - CONFERENCE PROCEEDINGS SE CONFERENCE PROCEEDINGS - INDIUM PHOSPHIDE AND RELATED MATERIALS LA English DT Proceedings Paper CT International Conference on Indium Phosphide and Related Materials CY MAY 11-15, 1998 CL UNIV TSUKUBA, UNIV HALL TSUKUBA, IBARAKI, JAPAN SP Japan Soc Appl Phys, IEEE, Lasers & Electro Optics Soc, IEEE, Electron Devices Soc, Inst Electr Informat & Commun Engineers, Optoelectr Ind & Technol Dev Assoc, Res & Dev Assoc Future Electron Devices, Commemorat Assoc Japan World Exposit, Marubun Res Promot Fdn, Nippon Sheet Glass Fdn Mat Sci & Engn, Ogasawara Fdn Promot Sci & Engn, Aixtron AG, Epichem, Epitaxial Prod Int Ltd HO UNIV TSUKUBA, UNIV HALL TSUKUBA AB Although there was some keen scientific interest in InP in the 70's, to a large extent IPRM signaled the "coming of age" of InP. IPRM was born because of a pent-up need to share the abundance of stimulating science and puzzling physics inherent in an emergent and exciting materials system. InP-based technology had potential for both new commercial markets and stringent military requirements. Scientific curiosity not withstanding, a significant, initial driving force for this new compound semiconductor system was the promise of very high-speed, broad-band communications using glass fibers that required compound semiconductor lasers. For the commercial market this meant orders of magnitude higher information throughput for less cost while for the military, secure, lightweight, broadband, EMI-free data links was the 'carrot'. Rapid advances in glass purification and extrusion techniques yielded impurity-free optical fibers with attenuation and dispersion minima that moved the optimum data transmission window from the GaAs-based 0.85nm to 1300nm and 1550nm, the sole regime of InP and its alloys. Long-haul optical systems were clearly on the horizon and telecommunications companies worldwide began to seriously consider adopting InP-based technology as a standard. Although opto-electronics applications was the initial driver, the evidence for superior electronic devices was quickly established. IPRM's role in this complex technology saga was to provide a focal point for technologists. It provided an open, truly international, workshop-like forum that fostered technology exchange while catalyzing the growth of the infrastructure so crucial to any fledgling venture. The fact that we are here in 1998 is ample evidence that IPRM has been an important factor in the development of InP and related materials. Beyond the flood of worldwide scientific journal publications heralding our new breakthroughs in InP, an assortment of new businesses have emerged, academic dynasties were created and existing ventures found IPRM a fertile breeding environment for maturation and new business directions((1)). C1 USAF, Res Lab, Sensors Electromagnet Technol Div, Hanscom AFB, MA 01731 USA. RP Lorenzo, J (reprint author), USAF, Res Lab, Sensors Electromagnet Technol Div, 80 Scott Rd, Hanscom AFB, MA 01731 USA. NR 0 TC 0 Z9 0 U1 1 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1092-8669 BN 0-7803-4220-8 J9 CONF P INDIUM PHOSPH PY 1998 BP 10 EP 13 DI 10.1109/ICIPRM.1998.712388 PG 4 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Materials Science, Characterization & Testing; Optics; Physics, Applied SC Engineering; Materials Science; Optics; Physics GA BL47Q UT WOS:000075657000003 ER PT S AU Bliss, D Bryant, G Jafri, I Prasad, V Gupta, K Farmer, R Chandra, M AF Bliss, D Bryant, G Jafri, I Prasad, V Gupta, K Farmer, R Chandra, M GP IEEE IEEE TI A new high-pressure system for synthesis and crystal growth of large diameter InP SO 1998 INTERNATIONAL CONFERENCE ON INDIUM PHOSPHIDE AND RELATED MATERIALS - CONFERENCE PROCEEDINGS SE CONFERENCE PROCEEDINGS - INDIUM PHOSPHIDE AND RELATED MATERIALS LA English DT Proceedings Paper CT International Conference on Indium Phosphide and Related Materials CY MAY 11-15, 1998 CL UNIV TSUKUBA, UNIV HALL TSUKUBA, IBARAKI, JAPAN SP Japan Soc Appl Phys, IEEE, Lasers & Electro Optics Soc, IEEE, Electron Devices Soc, Inst Electr Informat & Commun Engineers, Optoelectr Ind & Technol Dev Assoc, Res & Dev Assoc Future Electron Devices, Commemorat Assoc Japan World Exposit, Marubun Res Promot Fdn, Nippon Sheet Glass Fdn Mat Sci & Engn, Ogasawara Fdn Promot Sci & Engn, Aixtron AG, Epichem, Epitaxial Prod Int Ltd HO UNIV TSUKUBA, UNIV HALL TSUKUBA AB An advanced high-pressure crystal growth system for one-step synthesis and growth has been constructed from a design based on numerical simulations and experiments. Experimental work reported previously(1,2), optimizing the one-step in-situ process for synthesis and growth, served as a basis for developing the new furnace. A global model developed to simulate growth conditions in the prototype system, has contributed to our understanding of complex transport phenomena such as thermoelastic strain and dopant incorporation(3). Using both the experimental and the simulation results, we have designed a system to produce large diameter, high purity, low defect density compound semiconductor crystals at low cost. C1 USAF, Res Lab, Hanscom AFB, MA 01731 USA. RP Bliss, D (reprint author), USAF, Res Lab, Hanscom AFB, MA 01731 USA. NR 0 TC 1 Z9 1 U1 0 U2 3 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1092-8669 BN 0-7803-4220-8 J9 CONF P INDIUM PHOSPH PY 1998 BP 38 EP 41 DI 10.1109/ICIPRM.1998.712395 PG 4 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Materials Science, Characterization & Testing; Optics; Physics, Applied SC Engineering; Materials Science; Optics; Physics GA BL47Q UT WOS:000075657000010 ER PT S AU Cerny, C Kaspi, R Via, D Ebel, J DeSalvo, G Quach, T Bozada, C Dettmer, R Gillespie, J Jenkins, T Pettiford, C Schuermeyer, F Welch, R O'Keefe, M Stutz, E Taylor, E Van Nostrand, J AF Cerny, C Kaspi, R Via, D Ebel, J DeSalvo, G Quach, T Bozada, C Dettmer, R Gillespie, J Jenkins, T Pettiford, C Schuermeyer, F Welch, R O'Keefe, M Stutz, E Taylor, E Van Nostrand, J GP IEEE IEEE TI Experimental development and incorporation of strain in P-type GaAsSb/InAlAs single metal heterostructure field effect transistors SO 1998 INTERNATIONAL CONFERENCE ON INDIUM PHOSPHIDE AND RELATED MATERIALS - CONFERENCE PROCEEDINGS SE CONFERENCE PROCEEDINGS - INDIUM PHOSPHIDE AND RELATED MATERIALS LA English DT Proceedings Paper CT International Conference on Indium Phosphide and Related Materials CY MAY 11-15, 1998 CL UNIV TSUKUBA, UNIV HALL TSUKUBA, IBARAKI, JAPAN SP Japan Soc Appl Phys, IEEE, Lasers & Electro Optics Soc, IEEE, Electron Devices Soc, Inst Electr Informat & Commun Engineers, Optoelectr Ind & Technol Dev Assoc, Res & Dev Assoc Future Electron Devices, Commemorat Assoc Japan World Exposit, Marubun Res Promot Fdn, Nippon Sheet Glass Fdn Mat Sci & Engn, Ogasawara Fdn Promot Sci & Engn, Aixtron AG, Epichem, Epitaxial Prod Int Ltd HO UNIV TSUKUBA, UNIV HALL TSUKUBA AB The incorporation of bi-axially compressive strain has been experimentally designed into GaAsSb/LnAlAs heterostructures grown on InP substrates for improved electronic transport. The bi-axially compressive strain results from growing the GaAsSb off the lattice match to InP, through increased antimony composition. Dual Group V (As Sb) compositional control is achieved during molecular beam epitaxial growth through desorption mass spectroscopy and is found to be consistent with post deposition X-ray data. The biaxially compressive stress level measured after the heterostructure growth was on the order of 1 Gpa. The GaAsSb channel region is left unintentionally doped during processing to minimize coulombic scattering of the carriers by the ionized impurities. A novel, self-aligned, ion-implanted, single metal, electron-beam/optical lithography process is used to fabricate deep submicron p-type GaAsSb/InAlAs HFETs. Lattice-matched, enhancement-mode, 0.15 mu m GaAsSb/InAlAs p-HFETs demonstrated a transconductance (g(m)) of 16mS/mm and a cutoff frequency (f(t)) of 4 GHz. C1 AFRL, SND, Wright Patterson AFB, OH 45433 USA. RP Cerny, C (reprint author), AFRL, SND, Bldg 620 RM C2G69,2241 Av Circle, Wright Patterson AFB, OH 45433 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1092-8669 BN 0-7803-4220-8 J9 CONF P INDIUM PHOSPH PY 1998 BP 127 EP 130 DI 10.1109/ICIPRM.1998.712418 PG 4 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Materials Science, Characterization & Testing; Optics; Physics, Applied SC Engineering; Materials Science; Optics; Physics GA BL47Q UT WOS:000075657000033 ER PT S AU Dauplaise, HM Vaccaro, K Davis, A Waters, WD Lorenzo, JP AF Dauplaise, HM Vaccaro, K Davis, A Waters, WD Lorenzo, JP GP IEEE IEEE TI Passivation of InP with thin layers of MBE-grown CdS SO 1998 INTERNATIONAL CONFERENCE ON INDIUM PHOSPHIDE AND RELATED MATERIALS - CONFERENCE PROCEEDINGS SE CONFERENCE PROCEEDINGS - INDIUM PHOSPHIDE AND RELATED MATERIALS LA English DT Proceedings Paper CT International Conference on Indium Phosphide and Related Materials CY MAY 11-15, 1998 CL UNIV TSUKUBA, UNIV HALL TSUKUBA, IBARAKI, JAPAN SP Japan Soc Appl Phys, IEEE, Lasers & Electro Optics Soc, IEEE, Electron Devices Soc, Inst Electr Informat & Commun Engineers, Optoelectr Ind & Technol Dev Assoc, Res & Dev Assoc Future Electron Devices, Commemorat Assoc Japan World Exposit, Marubun Res Promot Fdn, Nippon Sheet Glass Fdn Mat Sci & Engn, Ogasawara Fdn Promot Sci & Engn, Aixtron AG, Epichem, Epitaxial Prod Int Ltd HO UNIV TSUKUBA, UNIV HALL TSUKUBA AB Thin layers of CdS were grown on (100) n-InP by molecular beam epitaxy (MBE). Substrates were pre-treated in an ammonia/thiourea solution, then annealed at similar to 150-250 degrees C in vacuo prior to CdS growth. A single effusion cell with a polycrystalline CdS source was used. Reflection high energy electron diffraction (RHEED) analysis showed surface reconstruction following predeposition anneals at 200 degrees C of sulfur-passivated InP. Subsequent CdS deposition at 200 degrees C resulted in lattice-matched epitaxial layers in the metastable cubic phase, as observed with RHEED. X-ray photo-electron spectroscopy (XPS) analysis of the CdS/InP structures showed that the near-surface of InP is phosphorus deficient following the pre-deposition anneal, with an In2S3 layer present at the substrate/CdS interface. Subsequent processing of MIS structures with CdS layers (25-85 Angstrom) between the InP and SiO2 resulted in MIS capacitors with consistently low density of interface states (2 x 10(11) eV(-1)cm(-2)) and hysteresis (20mV). C1 USAF, Res Lab, Optoelect Components Branch, Hanscom AFB, MA 01731 USA. RP Dauplaise, HM (reprint author), USAF, Res Lab, Optoelect Components Branch, Hanscom AFB, MA 01731 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1092-8669 BN 0-7803-4220-8 J9 CONF P INDIUM PHOSPH PY 1998 BP 455 EP 458 DI 10.1109/ICIPRM.1998.712521 PG 4 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Materials Science, Characterization & Testing; Optics; Physics, Applied SC Engineering; Materials Science; Optics; Physics GA BL47Q UT WOS:000075657000116 ER PT B AU Butler, JT Bright, VM Chu, PB Saia, RJ AF Butler, JT Bright, VM Chu, PB Saia, RJ GP IMAPS TI Adapting multichip module foundries for MEMS packaging SO 1998 INTERNATIONAL CONFERENCE ON MULTICHIP MODULES AND HIGH DENSITY PACKAGING, PROCEEDINGS LA English DT Proceedings Paper CT 1998 International Conference on Multichip Modules and High Density Packaging (MCM 98) CY APR 15-17, 1998 CL DENVER, CO SP IMAPS, IEEE, CPMT, EIA, MCM DE multichip modules; micro-electro-mechanical systems; packaging; MCM foundries AB Methods of packaging micro-electro-mechanical systems (MEMS) using advanced multichip module (MCM) foundry processes are described. MCM packaging provides an efficient solution for integration of MEMS with other microelectronic technologies. The MCM foundries investigated for MEMS packaging were the General Electric high density interconnect (HDI) and Chip-on-Flex (COF) as well as the Micro Module Systems (MMS) MCM-D process. Bulk and surface micromachined test die were packaged with CMOS electronics using these MCM foundries. Procedures were developed to successfully release and assemble the MEMS devices without degrading the MCM package or other die in the module. The use of MCM foundries enables the cost-effective development of microsystems in situations for which monolithic integration of MEMS and microelectronics is not suitable. C1 USAF, Inst Technol, Dept Elect Engn, Wright Patterson AFB, OH 45433 USA. RP Butler, JT (reprint author), USAF, Inst Technol, Dept Elect Engn, Wright Patterson AFB, OH 45433 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4850-8 PY 1998 BP 106 EP 111 DI 10.1109/ICMCM.1998.670763 PG 6 WC Computer Science, Hardware & Architecture; Engineering, Electrical & Electronic; Materials Science, Coatings & Films SC Computer Science; Engineering; Materials Science GA BK95T UT WOS:000073940900019 ER PT B AU Hill, RR AF Hill, RR BE Medeiros, DJ Watson, EF Carson, JS Manivannan, MS TI An analytical comparison of optimization problem generation methodologies SO 1998 WINTER SIMULATION CONFERENCE PROCEEDINGS, VOLS 1 AND 2 LA English DT Proceedings Paper CT 1998 Winter Simulation Conference on Simulation in the 21st-Century (WSC 98) CY DEC 13-16, 1998 CL WASHINGTON, D.C. AB Heuristics are an increasingly popular solution method for combinatorial optimization problems. Heuristic use often frees the modeler from some of the restrictions placed on classical optimization methods required to constrain problem complexity. As a result, modelers are using heuristics to tackle problems previously considered unsolvable, improve performance over classical optimization methods, and open new avenues of empirical study. Researchers should fully understand key test problem attributes and sources of variation to produce efficient and effective optimization studies. These problem attributes and sources of variation are reviewed. Problem correlation structure significantly effects algorithm performance but is often overlooked or ignored in empirical studies. This paper analyzes the correlation structure among a set of standard multidimensional knapsack problems and recommends an improved approach to synthetic, or randomly generated optimization problems for the empirical study of solution algorithms for combinatorial optimization problems. C1 USAF, Inst Technol, Dept Operat Sci, Wright Patterson AFB, OH 45433 USA. RP Hill, RR (reprint author), USAF, Inst Technol, Dept Operat Sci, 2950 P St,Bldg 640, Wright Patterson AFB, OH 45433 USA. NR 16 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-5133-9 PY 1998 BP 609 EP 615 PG 7 WC Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering; Engineering, Multidisciplinary; Engineering, Manufacturing; Engineering, Electrical & Electronic; Transportation SC Computer Science; Engineering; Transportation GA BM30S UT WOS:000078340100082 ER PT B AU Ryan, JL Bailey, TG Moore, JT Carlton, WB AF Ryan, JL Bailey, TG Moore, JT Carlton, WB BE Medeiros, DJ Watson, EF Carson, JS Manivannan, MS TI Reactive Tabu Search in unmanned aerial reconnaissance simulations SO 1998 WINTER SIMULATION CONFERENCE PROCEEDINGS, VOLS 1 AND 2 LA English DT Proceedings Paper CT 1998 Winter Simulation Conference on Simulation in the 21st-Century (WSC 98) CY DEC 13-16, 1998 CL WASHINGTON, D.C. AB We apply a Reactive Tabu Search (RTS) heuristic within a discrete-event simulation to solve routing problems for Unmanned Aerial Vehicles (UAVs). Our formulation represents this problem as a multiple Traveling Salesman Problem with time windows (mTSPTW), with the objective of maximizing expected target coverage. Incorporating weather and probability of UAV survival at each target as random inputs, the RTS heuristic in the simulation searches for the best solution in each realization of the problem scenario in order to identify those routes that are robust to variations in weather, threat, or target service times. We present an object-oriented implementation of this approach using CACI's simulation language MODSIM. C1 USAF, Inst Technol, Dept Operat Sci, Wright Patterson AFB, OH 45433 USA. RP Ryan, JL (reprint author), USAF, Inst Technol, Dept Operat Sci, 2950 P St,Bldg 640 AFIT ENS, Wright Patterson AFB, OH 45433 USA. NR 9 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-5133-9 PY 1998 BP 873 EP 879 PG 7 WC Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering; Engineering, Multidisciplinary; Engineering, Manufacturing; Engineering, Electrical & Electronic; Transportation SC Computer Science; Engineering; Transportation GA BM30S UT WOS:000078340100118 ER PT B AU Farr, SD Sisti, AF AF Farr, SD Sisti, AF BE Medeiros, DJ Watson, EF Carson, JS Manivannan, MS TI The Virtual M & S Lyceum: A consortium for modeling and simulation technology SO 1998 WINTER SIMULATION CONFERENCE PROCEEDINGS, VOLS 1 AND 2 LA English DT Proceedings Paper CT 1998 Winter Simulation Conference on Simulation in the 21st-Century (WSC 98) CY DEC 13-16, 1998 CL WASHINGTON, D.C. AB This paper addresses the opportunity to put into place a virtual consortium for modeling and simulation. While periodic conferences such as the Winter Simulation Conference are tremendously vital to the continued growth of modeling and simulation research, they do not offer the day-to-day technical exchange that can now be made possible with matured collaborative technologies. We call this web-based meeting place Virtual M&S Lyceum, after the research institute founded by Aristotle in 335 BC; where young Athenian students were imparted great knowledge and insight by the great minds of the time. (Interestingly enough, the physical Lyceum recently came into the news again after 2300 years, when advance excavation crews, preparing for the construction of the new Museum of Modern Art, unearthed what is believed to be Aristotle's original school). It is in the spirit of this "hall of learning" that we try to create a place - albeit a virtual one - in which great minds can once again impart knowledge and insight to the masses. C1 USAF, Res Lab, IFSB, Rome, NY 13441 USA. RP Farr, SD (reprint author), USAF, Res Lab, IFSB, 525 Brooks Rd, Rome, NY 13441 USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-5133-9 PY 1998 BP 1677 EP 1680 PG 4 WC Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering; Engineering, Multidisciplinary; Engineering, Manufacturing; Engineering, Electrical & Electronic; Transportation SC Computer Science; Engineering; Transportation GA BM30S UT WOS:000078340100229 ER PT S AU Cinibulk, MK AF Cinibulk, MK BE Bray, D TI Synthesis of calcium hexaluminate and lanthanum hexaluminate fiber coatings SO 22ND ANNUAL CONFERENCE ON COMPOSITES, ADVANCED CERAMICS, MATERIALS, AND STRUCTURES: A SE CERAMIC ENGINEERING AND SCIENCE PROCEEDINGS LA English DT Proceedings Paper CT 22nd Annual Conference on Composites, Advanced Ceramics, Materials, and Structures CY JAN 20-24, 1998 CL COCOA BEACH, FL ID PRECURSORS; ALUMINA AB A cleavable hexaluminate fiber-matrix interphase requires that phase-pure, textured coatings be obtained at less than 1200-1300 degrees C to minimize polycrystalline oxide-fiber degradation. The synthesis of phase-pure powders and texturing of thin films at reduced temperatures using polymeric precursors and metal-oxide dopants are discussed. Calcium hexaluminate coatings were not obtained on polycrystalline fibers due to CaO segregation; coatings of iron-doped lanthanum hexaluminate were produced at 1100 degrees C, but basal-texture was not obtained. C1 USAF, Res Lab, Mat & Mfg Directorate, Wright Patterson AFB, OH 45433 USA. RP Cinibulk, MK (reprint author), USAF, Res Lab, Mat & Mfg Directorate, Wright Patterson AFB, OH 45433 USA. NR 21 TC 5 Z9 5 U1 0 U2 0 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, WESTERVILLE, OH 43081-8720 USA SN 0196-6219 J9 CERAM ENG SCI PROC PY 1998 VL 19 IS 3 BP 27 EP 35 PG 9 WC Materials Science, Ceramics; Materials Science, Characterization & Testing; Materials Science, Composites SC Materials Science GA BN01Q UT WOS:000080406200004 ER PT S AU Zawada, LP AF Zawada, LP BE Bray, D TI Longitudinal and transthickness tensile behavior of several oxide oxide composites SO 22ND ANNUAL CONFERENCE ON COMPOSITES, ADVANCED CERAMICS, MATERIALS, AND STRUCTURES: A SE CERAMIC ENGINEERING AND SCIENCE PROCEEDINGS LA English DT Proceedings Paper CT 22nd Annual Conference on Composites, Advanced Ceramics, Materials, and Structures CY JAN 20-24, 1998 CL COCOA BEACH, FL ID DAMAGE-TOLERANT AB Four oxide/oxide ceramic matrix composites (CMCs) were investigated in longitudinal tension and transthickness tension. The longitudinal tests were conducted at 23 degrees C and 1000 degrees C, while the transthickness tension tests were only performed at 23 degrees C. The four CMCs showed good high temperature tensile behavior, with the tensile strength at 1000 degrees C only dropping by 7-16%. Transthickness tension results revealed that a N610/Aluminosilicate system demonstrated an average strength of 7.1 MPa, while the remaining three systems averaged approximately 2.8 MPa. C1 USAF, Res Lab, Mat & Mfg Directorate, Wright Patterson AFB, OH 45433 USA. RP Zawada, LP (reprint author), USAF, Res Lab, Mat & Mfg Directorate, Wright Patterson AFB, OH 45433 USA. NR 10 TC 28 Z9 28 U1 1 U2 1 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, WESTERVILLE, OH 43081-8720 USA SN 0196-6219 J9 CERAM ENG SCI PROC PY 1998 VL 19 IS 3 BP 327 EP 339 PG 13 WC Materials Science, Ceramics; Materials Science, Characterization & Testing; Materials Science, Composites SC Materials Science GA BN01Q UT WOS:000080406200036 ER PT S AU Jero, PD Rebillat, F Kent, DJ Jones, JG AF Jero, PD Rebillat, F Kent, DJ Jones, JG BE Bray, D TI Crystallization of lanthanum hexaluminate from MOCVD precursors SO 22ND ANNUAL CONFERENCE ON COMPOSITES, ADVANCED CERAMICS, MATERIALS, AND STRUCTURES: A SE CERAMIC ENGINEERING AND SCIENCE PROCEEDINGS LA English DT Proceedings Paper CT 22nd Annual Conference on Composites, Advanced Ceramics, Materials, and Structures CY JAN 20-24, 1998 CL COCOA BEACH, FL C1 USAF, Res Lab, Wright Patterson AFB, OH 45433 USA. RP Jero, PD (reprint author), USAF, Res Lab, Wright Patterson AFB, OH 45433 USA. NR 4 TC 6 Z9 6 U1 1 U2 4 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, WESTERVILLE, OH 43081-8720 USA SN 0196-6219 J9 CERAM ENG SCI PROC PY 1998 VL 19 IS 3 BP 359 EP 360 PG 2 WC Materials Science, Ceramics; Materials Science, Characterization & Testing; Materials Science, Composites SC Materials Science GA BN01Q UT WOS:000080406200039 ER PT S AU Moore, EH Smith, RA AF Moore, EH Smith, RA BE Bray, D TI Dust erosion testing of coated AETB tile for aerospace applications SO 22ND ANNUAL CONFERENCE ON COMPOSITES, ADVANCED CERAMICS, MATERIALS, AND STRUCTURES: B SE CERAMIC ENGINEERING AND SCIENCE PROCEEDINGS LA English DT Proceedings Paper CT 22nd Annual Conference on Composites, Advanced Ceramics, Materials, and Structures CY JAN 20-24, 1998 CL COCOA BEACH, FL AB The durability of alumina enhanced thermal barrier (AETB) tile has been found unacceptable with regard to meeting long-term. performance requirements under use conditions. A tetra-ethyl-ortho-silicate (TEOS)-coated AETB tile's integrity and properties may degrade under some chemical, physical, and thermal environments. A dust erosion apparatus (DEA) was used to address the physical degradation of several AETB tile concepts. These concepts looked at the durability of the bare AETB tile, TEOS-coated AETB tile, an aluminosilicate-coated AETB tile, and an aluminosilicate-coated TEOS-coated AETB tile. Results of this investigation, as well as its test parameters, will be discussed. C1 AFRL, MLLM, Wright Patterson AFB, OH 45433 USA. RP Moore, EH (reprint author), AFRL, MLLM, Bldg 655,2230 10th St,Suite 1, Wright Patterson AFB, OH 45433 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, WESTERVILLE, OH 43081-8720 USA SN 0196-6219 J9 CERAM ENG SCI PROC PY 1998 VL 19 IS 4 BP 303 EP 310 PG 8 WC Materials Science, Ceramics; Materials Science, Composites SC Materials Science GA BN01R UT WOS:000080406400034 ER PT B AU Purdy, S Barnhart, D Johnston, R AF Purdy, S Barnhart, D Johnston, R BE Boukerche, A Reynolds, P TI Latency measurements obtained from the simulation network analysis project SO 2ND INTERNATIONAL WORKSHOP ON DISTRIBUTED INTERACTIVE SIMULATION AND REAL-TIME APPLICATIONS, PROCEEDINGS LA English DT Proceedings Paper CT 2nd International Workshop on Distributed Interactive Simulation and Real-Time Applications CY JUL 19-20, 1998 CL MONTREAL, CANADA SP IEEE Comp Soc Tech Comm on Pattern anal & Machine Intelligence AB Simulator time-delays (latencies) are an important factor in the simulation world. In research and/or training, an), high-fidelity simulation is adversely affected by latencies. The Simulation Network Analysis Project ((SNAP) was developed to investigate these latencies. The SNAP system can measure latencies between vital points (stick input, state variables, visual displays, and the Network Interface Unit - or any other points of interest) in a stand-alone simulator and between networked simulators. Data correlation is accomplished via Global Positioning System (GPS) time-stamping. This paper will report on the findings from past latency measurements and key lessons learned. Factors affecting latency: such as network configuration (hardware and software), simulator modifications; and network loading will be discussed. C1 USAF, Res Lab, Control Integrat & Assessment Branch, VACD, Dayton, OH 45433 USA. RP Purdy, S (reprint author), USAF, Res Lab, Control Integrat & Assessment Branch, VACD, Dayton, OH 45433 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA BN 0-8186-8594-8 PY 1998 BP 71 EP 81 DI 10.1109/DISRTA.1998.694568 PG 11 WC Computer Science, Artificial Intelligence; Computer Science, Theory & Methods SC Computer Science GA BL38S UT WOS:000075345500008 ER PT B AU Anderson, HJ Anderson, DP Kearns, KM AF Anderson, HJ Anderson, DP Kearns, KM BE Kliger, HS Rasmussen, BM Pilato, LA Tolle, TB TI Microcellular pitch-based carbon foams blown with helium gas SO 43RD INTERNATIONAL SAMPE SYMPOSIUM AND EXHIBITION ON MATERIALS AND PROCESS AFFORDABILITY - KEYS TO THE FUTURE, VOL 43 LA English DT Proceedings Paper CT 43rd International SAMPE Symposium and Exhibition on Materials and Process Affordability - Keys to the Future CY MAY 31-JUN 04, 1998 CL ANAHEIM, CA SP Soc Adv Mat & Proc Engn DE carbon foam; microcellular structural foam; and foam processing AB Microcellular graphite foams were produced with graphitic alignment along the struts from anisotropic pitch. The foams were created by first pressurizing the pitch with helium gas. The pitch temperature was raised above its softening point. At temperature, more helium was added to the system and held for a length of time. The system was finally vented to the atmosphere, generating the porous material(foam). The pores created in the foam, form a three dimensional, interconnected network of struts. The graphite planes are aligned along the struts by the expansion of the cells in the foam, similar to the spinning mechanism for fibers. The foams were carbonized in a similar manner as pitch based fibers. Open-celled graphitic foams possess excellent specific mechanical properties. Current work including foam morphology, and microscopy will be discussed. C1 USAF, Mat & Mfg Directorate, Wright Patterson AFB, OH 45433 USA. RP Anderson, HJ (reprint author), USAF, Mat & Mfg Directorate, 2941 P St Ste 1, Wright Patterson AFB, OH 45433 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC ADVANCEMENT MATERIAL & PROCESS ENGINEERING PI COVINA PA 1161 PARKVIEW DR,, COVINA, CA 91724-3748 USA BN 0-938994-79-4 PY 1998 BP 756 EP 762 PG 7 WC Materials Science, Multidisciplinary; Materials Science, Characterization & Testing; Materials Science, Composites; Polymer Science SC Materials Science; Polymer Science GA BL49K UT WOS:000075698500070 ER PT B AU Kearns, KM AF Kearns, KM BE Kliger, HS Rasmussen, BM Pilato, LA Tolle, TB TI Recent developments in carbon-carbon composites SO 43RD INTERNATIONAL SAMPE SYMPOSIUM AND EXHIBITION ON MATERIALS AND PROCESS AFFORDABILITY - KEYS TO THE FUTURE, VOL 43 LA English DT Proceedings Paper CT 43rd International SAMPE Symposium and Exhibition on Materials and Process Affordability - Keys to the Future CY MAY 31-JUN 04, 1998 CL ANAHEIM, CA SP Soc Adv Mat & Proc Engn DE carbon carbon composites; thermal management; space application; aircraft applications AB Carbon-carbon composites have historically been used for high temperature, ablative, and/or high friction applications. However, carbon has many other unique properties such as high thermal conductivity, tailorable mechanical stiffness and strength, chemical inertness, low thermal expansion, and low density. Recent research in carbon-carbon composites has taken advantage of these properties. This has developed opportunities for carbon-carbon in spacecraft and aircraft thermal management, electronic packaging thermal control, and power storage applications. Future uses of carbon-carbon will build on these properties and take advantage of some of the other properties of carbon, for instance, high temperature stability, tailorable electrical conductivity, etc. Applications that are currently being investigated as well as some potential future ones will be discussed. The advantages and pitfalls of carbon-carbon versus the current chosen materials will be outlined. C1 USAF, Res Lab, Mat & Mfg Directorate, Wright Patterson AFB, OH 45433 USA. RP Kearns, KM (reprint author), USAF, Res Lab, Mat & Mfg Directorate, Wright Patterson AFB, OH 45433 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU SOC ADVANCEMENT MATERIAL & PROCESS ENGINEERING PI COVINA PA 1161 PARKVIEW DR,, COVINA, CA 91724-3748 USA BN 0-938994-79-4 PY 1998 BP 1362 EP 1369 PG 8 WC Materials Science, Multidisciplinary; Materials Science, Characterization & Testing; Materials Science, Composites; Polymer Science SC Materials Science; Polymer Science GA BL49K UT WOS:000075698500128 ER PT B AU Farmer, JD Janke, CJ Lopata, VJ AF Farmer, JD Janke, CJ Lopata, VJ BE Kliger, HS Rasmussen, BM Pilato, LA Tolle, TB TI The electron beam cure of epoxy paste adhesives SO 43RD INTERNATIONAL SAMPE SYMPOSIUM AND EXHIBITION ON MATERIALS AND PROCESS AFFORDABILITY - KEYS TO THE FUTURE, VOL 43 LA English DT Proceedings Paper CT 43rd International SAMPE Symposium and Exhibition on Materials and Process Affordability - Keys to the Future CY MAY 31-JUN 04, 1998 CL ANAHEIM, CA SP Soc Adv Mat & Proc Engn AB Recently developed epoxy paste adhesives were electron beam cured and experimentally explored to determine their suitability for use in an aerospace-quality aircraft component. There were two major goals for this program. The first was to determine whether the electron beam-curable paste adhesives were capable of meeting the requirements of the U.S. Air Force T-38 supersonic jet trainer's composite windshield frame. The T-38 windshield frame's arch is currently manufactured by bonding thin stainless steel pries using an aerospace-grade thermally-cured epoxy Nm adhesive. The second goal was to develop the lowest cost hand layup and debulk process that could be used to produce laminated steel plies with acceptable properties. The laminate properties examined to determine adhesive suitability include laminate mechanical and physical properties at room, adhesive tack, out-time capability, and the debulk requirements needed to achieve these properties. Eighteen paste adhesives and four scrim cloths were experimentally examined using this criteria. One paste adhesive was found to have suitable characteristics in each of these categories and was later chosen for the manufacture of the T-38 windshield frame. This experimental study shows that by using low cost. debulk and layup processes, the electron beam-cured paste adhesive mechanical and physical properties meet the specifications of the T-38 composite windshield frame. C1 USAF, Adv Composites Program Off, McClellan AFB, CA 95652 USA. RP Farmer, JD (reprint author), USAF, Adv Composites Program Off, WL MLS OL, McClellan AFB, CA 95652 USA. RI Janke, Christopher/E-1598-2017 OI Janke, Christopher/0000-0002-6076-7188 NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC ADVANCEMENT MATERIAL & PROCESS ENGINEERING PI COVINA PA 1161 PARKVIEW DR,, COVINA, CA 91724-3748 USA BN 0-938994-79-4 PY 1998 BP 1639 EP 1646 PG 8 WC Materials Science, Multidisciplinary; Materials Science, Characterization & Testing; Materials Science, Composites; Polymer Science SC Materials Science; Polymer Science GA BL49K UT WOS:000075698500158 ER PT B AU Farmer, JD Warnock, RB Janke, CJ Lopata, VJ AF Farmer, JD Warnock, RB Janke, CJ Lopata, VJ BE Kliger, HS Rasmussen, BM Pilato, LA Tolle, TB TI Electron-beam cure of composite T-38 windshield frame/arch SO 43RD INTERNATIONAL SAMPE SYMPOSIUM AND EXHIBITION ON MATERIALS AND PROCESS AFFORDABILITY - KEYS TO THE FUTURE, VOL 43 LA English DT Proceedings Paper CT 43rd International SAMPE Symposium and Exhibition on Materials and Process Affordability - Keys to the Future CY MAY 31-JUN 04, 1998 CL ANAHEIM, CA SP Soc Adv Mat & Proc Engn DE aerospace; electron beam curing; manufacturing AB Recently-developed electron-beam-curable epoxy resin paste adhesives and laminating resins were explored to determine their suitability for use in aircraft components. The application chosen for demonstration was the composite windshield frame/arch of the T-38 Talon, the U.S. Air Force's primary supersonic jet training aircraft. The current configuration of the T-38 windshield frame/arch, designed by the USAF Advanced Composites Program Office, incorporates thermally-cured epoxy prepreg and film adhesive. Two windshield assemblies were fabricated, substituting electron-beam materials for thermally cured materials. Fabrication of the innerskin, bulkhead doubler, and fairing fiberglass/epoxy components took place using the AECL Whiteshell Laboratory's I-10/1 Electron Accelerator (10 MeV, 1 kW). The arch is 25.4 cm thick, containing 15 mm of stainless steel. Curing through this cross-section required the use of X-rays. The arch was cured at E-Beam Services using a 50 kW accelerator. Assembly of the components was done at McClellan AFB, CA using the conventional thermally-cured adhesives. The T-38 windshield frame/arch must be able to withstand the impact of a 4 pound bird at 400 knots. The new e-beam frame/arch was tested at the PPG bird-strike facility in Huntsville, AL. Results of the test, and comparisons to the thermally-cured frame and arch are discussed. C1 USAF, Adv Composites Program Off, AFRL MLS OL, Livermore, CA 95652 USA. RP Farmer, JD (reprint author), USAF, Adv Composites Program Off, AFRL MLS OL, Livermore, CA 95652 USA. RI Janke, Christopher/E-1598-2017 OI Janke, Christopher/0000-0002-6076-7188 NR 0 TC 1 Z9 1 U1 0 U2 0 PU SOC ADVANCEMENT MATERIAL & PROCESS ENGINEERING PI COVINA PA 1161 PARKVIEW DR,, COVINA, CA 91724-3748 USA BN 0-938994-79-4 PY 1998 BP 1647 EP 1659 PG 13 WC Materials Science, Multidisciplinary; Materials Science, Characterization & Testing; Materials Science, Composites; Polymer Science SC Materials Science; Polymer Science GA BL49K UT WOS:000075698500159 ER PT B AU Buynak, C Cordell, T Golis, M AF Buynak, C Cordell, T Golis, M BE Kliger, HS Rasmussen, BM Pilato, LA Tolle, TB TI Air force research laboratory program for nondestructive testing of composite materials SO 43RD INTERNATIONAL SAMPE SYMPOSIUM AND EXHIBITION ON MATERIALS AND PROCESS AFFORDABILITY - KEYS TO THE FUTURE, VOL 43 LA English DT Proceedings Paper CT 43rd International SAMPE Symposium and Exhibition on Materials and Process Affordability - Keys to the Future CY MAY 31-JUN 04, 1998 CL ANAHEIM, CA SP Soc Adv Mat & Proc Engn DE non-destructive evaluation; composite components; composite structures AB The United States Air Force (USAF) has maintained a long tradition in the support of research activities related to the Nondestructive Evaluation (NDE) of both metal and composite materials. The results of several of such efforts are being presented at this SAMPE conference. This paper has been prepared in order to communicate to the technical community the current approaches being investigated and some of the initiatives being used to couple the concepts of nondestructive materials evaluation to the continuing development of practical applications for composite materials. Outlined below are some of the recent programs which are resulting in improved means for testing composite materials and plans for future developments aimed at transitioning these improvements into Air Force and industrial practices. C1 USAF, Res Lab, Washington, DC 20330 USA. RP Buynak, C (reprint author), USAF, Res Lab, Washington, DC 20330 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU SOC ADVANCEMENT MATERIAL & PROCESS ENGINEERING PI COVINA PA 1161 PARKVIEW DR,, COVINA, CA 91724-3748 USA BN 0-938994-79-4 PY 1998 BP 1724 EP 1729 PG 6 WC Materials Science, Multidisciplinary; Materials Science, Characterization & Testing; Materials Science, Composites; Polymer Science SC Materials Science; Polymer Science GA BL49K UT WOS:000075698500167 ER PT S AU West, RL Wickert, MA AF West, RL Wickert, MA GP IEEE TI Utilizing wireless ATM over OFDM for a rural communications infrastructure SO 48TH IEEE VEHICULAR TECHNOLOGY CONFERENCE, VOLS 1-3 SE IEEE VEHICULAR TECHNOLOGY CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 48th IEEE Vehicular Technology Conference (VTC 98) CY MAY 18-21, 1998 CL OTTAWA, CANADA SP IEEE, Vehicular Technol Soc, IEEE, Ottawa Sect AB This paper describes research in support of a project to implement a wireless ATM network utilizing OFDM for rural communities. There are many issues of the wireless environment that OFDM helps to combat and ATM appears to be a useful protocol for implementing present and future data requirements. The main focus of the paper is a simulation model of a contention based reservation channel, connection admission control, and output buffering analysis. The results appear to support the conclusion that wireless ATM can support a vast mix of data requirements of today and tomorrow. C1 USAF Acad, Dept Elect Engn, Colorado Springs, CO 80840 USA. RP West, RL (reprint author), USAF Acad, Dept Elect Engn, Colorado Springs, CO 80840 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1090-3038 BN 0-7803-4320-4 J9 IEEE VTC P PY 1998 BP 1200 EP 1203 PG 4 WC Engineering, Electrical & Electronic; Telecommunications; Transportation SC Engineering; Telecommunications; Transportation GA BL27R UT WOS:000075144500242 ER PT B AU Myers, L Wuilleumier, M AF Myers, L Wuilleumier, M BE Cantu, FJ Soto, R Liebowitz, J Sucar, E TI Using meta-knowledge in a coordinating expert system SO 4TH WORLD CONGRESS OF EXPERT SYSTEMS, VOL 1 AND 2: APPLICATION OF ADVANCED INFORMATION TECHNOLOGIES LA English DT Proceedings Paper CT 4th World Congress of Expert Systems - Application of Advanced Information Technologies CY MAR 16-20, 1998 CL INST TECNOLOG & ESTUDIOS SUPER MONTERREY, MEXICO CITY, MEXICO SP CEMEX, TV Azteca, ISIS, Mexican Soc Artificial Intelligence, CONACYT REDII, Amer Assoc Artificial Intelligence, Inst Technol & Estudios Super Monterrey, Ctr Artificial Intelligence HO INST TECNOLOG & ESTUDIOS SUPER MONTERREY AB The Intelligent Computer Aided Design System (ICADS) is a series of systems developed to assist building architects throughout the design activity. The research involves experiments with many different hardware, software, and conceptual problems and their solutions. This paper features the Cooperation Expert Acquisition Module (CEAM) which provides a theory for development of a Coordination Expert (CE) for ICADS. CEAM uses meta-knowledge to implement four general strategies replacing all previous CE domain rules. CEAM makes it possible to better teach the formulation of CE rules and to develop Coordination Experts more effectively. C1 USAF Acad, Colorado Springs, CO 80840 USA. RP Myers, L (reprint author), USAF Acad, Colorado Springs, CO 80840 USA. NR 0 TC 0 Z9 0 U1 0 U2 2 PU COGNIZANT COMMUNICATION CORP PI ELMSFORD PA 3 HARTSDALE RD, ELMSFORD, NY 10523-3701 USA BN 1-882345-22-3 PY 1998 BP 391 EP 398 PG 8 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Computer Science, Information Systems; Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering; Computer Science, Theory & Methods SC Automation & Control Systems; Computer Science GA BL16A UT WOS:000074517400062 ER PT J AU Webb, JT Pilmanis, AA AF Webb, JT Pilmanis, AA TI A new preoxygenation procedure for extravehicular activity (EVA) SO ACTA ASTRONAUTICA LA English DT Article ID DECOMPRESSION AB A 10.2 psi staged-decompression schedule or a 4-hour preoxygenation at 14.7 psi is required prior to extravehicular activity (EVA) to reduce decompression sickness (DCS) risk. Results of recent research at the Air Force Research Laboratory (AFRL) showed that a 1-hour resting preoxygenation followed by a 4-hour, 4.3 psi exposure resulted in 77% DCS risk (N=26), while the same profile beginning with 10 min of exercise at 75% of VO2peak during preoxygenation reduced the DCS risk to 42% (P<.03; N=26). A 4-hour preoxygenation without exercise followed by the 4.3 psi exposure resulted in 47% DCS risk (N=30). The 1-hour preoxygenation with exercise and the 4-hour preoxygenation without exercise results were not significantly different. Elimination of either 3 hours of preoxygenation or 12 hours of staged-decompression are compelling reasons to consider incorporation of exercise-enhanced preoxygenation. (C) 1998 Published by Elsevier Science Ltd. All rights reserved. C1 KRUG Life Sci Inc, AFRL, HEPR, Brooks AFB, TX 78235 USA. RP Webb, JT (reprint author), KRUG Life Sci Inc, AFRL, HEPR, 2504 Gillingham Dr,Suite 25, Brooks AFB, TX 78235 USA. NR 11 TC 10 Z9 10 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0094-5765 J9 ACTA ASTRONAUT JI Acta Astronaut. PD JAN-APR PY 1998 VL 42 IS 1-8 SI SI BP 115 EP 122 DI 10.1016/S0094-5765(98)00111-8 PG 8 WC Engineering, Aerospace SC Engineering GA 113KH UT WOS:000075549800012 PM 11541597 ER PT S AU Ryan, PT Fugate, RQ Langlois, M Sandler, DG AF Ryan, PT Fugate, RQ Langlois, M Sandler, DG BE Bonaccini, D Tyson, RK TI Scattered energy at the Starfire Optical Range 3.5 m adaptive optic telescope SO ADAPTIVE OPTICAL SYSTEM TECHNOLOGIES, PARTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Adaptive Optical System Technologies CY MAR 23-26, 1998 CL KONA, HI SP SPIE, European So Observ DE exosolar planets; adaptive optics AB In order to image faint stellar companions from the ground, high resolution adaptive optics (AO) is needed to correct atmospheric seeing. The 3.5 m AO system at the Starfire Optical Range (SOR) was used to confirm theoretical models of scattered light. Halo levels were reduced by a 50% at 0.5 ", which, when combined with the increased Strehl ratio, improved the gain by a factor of 23. Speckle lifetimes ranged from 20 ms at 0.1 " (twice the diffraction limit) to 4 ms at 0.4 ", much longer than the 0.7 ms correction time. These results show good agreement with predictions for current technology and reveal no limitations in principle to detection of exo-solar planets using AO systems with higher speed and resolution. C1 USAF, RL, DES, Starfire Opt Range, Kirtland AFB, NM 87117 USA. RP Ryan, PT (reprint author), USAF, RL, DES, Starfire Opt Range, Kirtland AFB, NM 87117 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2800-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3353 BP 107 EP 115 DI 10.1117/12.321641 PG 9 WC Optics SC Optics GA BL80V UT WOS:000076793400012 ER PT S AU Whiteley, MR Welsh, BM Roggemann, MC AF Whiteley, MR Welsh, BM Roggemann, MC BE Bonaccini, D Tyson, RK TI Effect of modal atmospheric compensation on angular anisoplanatism in optical interferometric imaging SO ADAPTIVE OPTICAL SYSTEM TECHNOLOGIES, PARTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Adaptive Optical System Technologies CY MAR 23-26, 1998 CL KONA, HI SP SPIE, European So Observ DE optical interferometry; atmospheric optics; adaptive optics AB Turbulence-induced phase aberrations cause the fringe pattern observed in an optical interferometer to change randomly. For long exposure measurements, the aperture-averaged mean-square differential phase between apertures comprising the interferometer baseline attenuates fringe visibility measurements, and thus reduces the ability to recover spatial-frequency spectrum information for the object being imaged. Application of modal atmospheric phase correction in each aperture of the interferometer reduces the degradation of visibility measurements when the turbulence-induced phase is measured with a wave front sensing device. For objects of interest in optical interferometric imaging, light levels are insufficient for adequate wave front sensing. Thus, a nearby naturally-occurring source must be used for modal compensation. Since this beacon is separated from the object being imaged, angular anisoplanatic effects are introduced which limit the benefits gained by the turbulence compensation. In this work, we quantify the interaperture correlation of modal aberrations, including finite outer scale and angular anisoplanatic effects. These quantities determine the residual phase upon correction of each aberration mode. For given levels of modal correction and relative aperture diameter D/tau(0) we establish the maximum angular separation between the beacon and the object being imaged that corresponds to an aperture-averaged mean-square residual differential phase less than 1rad(2). For D/tau(0) = 5, we show this limit to be approximately 3 times the isoplanatic angle, theta(0). For D/tau(0) = 30, however, the beacon offset is limited to approximately 0.2 theta(0). C1 USAF, Inst Technol, Dept Engn Phys, Wright Patterson AFB, OH 45433 USA. RP Whiteley, MR (reprint author), USAF, Inst Technol, Dept Engn Phys, 2950 P St,Bldg 640, Wright Patterson AFB, OH 45433 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2800-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3353 BP 177 EP 188 DI 10.1117/12.321675 PG 12 WC Optics SC Optics GA BL80V UT WOS:000076793400020 ER PT S AU De la Rue, IA Ellerbroek, BL AF De la Rue, IA Ellerbroek, BL BE Bonaccini, D Tyson, RK TI A study of multiple guide stars to improve the performance of laser guide star adaptive optical systems SO ADAPTIVE OPTICAL SYSTEM TECHNOLOGIES, PARTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Adaptive Optical System Technologies CY MAR 23-26, 1998 CL KONA, HI SP SPIE, European So Observ DE adaptive optics; laser guide stars; multiple laser guide stars; anisoplanatism AB Multiple guide stars are studied as a means of improving the performance of laser guide star (LGS) adaptive optical (AO) systems by reducing the effects of anisoplanatism. Previous work has shown that combining one sodium LGS and one Rayleigh LGS reduces tilt anisoplanatism for some turbulence profiles. In this paper, we investigate two scenarios of multiple guide star configurations. In the first scenario, AO correction based on three or more sodium beacons is studied. The second scenario investigates the use of a single sodium beacon in conjunction with a single Rayleigh beacon. For each of these cases, two turbulence profiles, two deformable mirror conjugate altitudes, numerous tip-tilt guide star offsets, and two WFS subaperture array sizes are investigated. The best results of the two scenarios are determined and compared in terms of Strehl Ratio and residual tilt. C1 USAF, Res Lab, DES, Starfire Opt Range, Kirtland AFB, NM 87117 USA. RP De la Rue, IA (reprint author), USAF, Res Lab, DES, Starfire Opt Range, 3550 Aberdeen Ave SE, Kirtland AFB, NM 87117 USA. NR 0 TC 7 Z9 7 U1 1 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2800-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3353 BP 310 EP 319 DI 10.1117/12.321723 PG 10 WC Optics SC Optics GA BL80V UT WOS:000076793400034 ER PT S AU Radick, RR Rimmele, TR Dunn, RB AF Radick, RR Rimmele, TR Dunn, RB BE Bonaccini, D Tyson, RK TI The image improvement program at the NSO/SP vacuum Tower Solar Telescope SO ADAPTIVE OPTICAL SYSTEM TECHNOLOGIES, PARTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Adaptive Optical System Technologies CY MAR 23-26, 1998 CL KONA, HI SP SPIE, European So Observ DE telescopes; solar telescopes; correlation tracking; active optics AB Over the past several years, a number of steps have been taken to improve the optical performance of the Vacuum Tower Solar Telescope at Sacramento Peak. We believe that the optical system of the telescope is now corrected to better that 1/10 wave rms after these improvements. C1 USAF, Res Lab, Space Hazards Branch, Sunspot, NM 88349 USA. RP Radick, RR (reprint author), USAF, Res Lab, Space Hazards Branch, Sunspot, NM 88349 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2800-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3353 BP 621 EP 627 DI 10.1117/12.321628 PG 7 WC Optics SC Optics GA BL80V UT WOS:000076793400068 ER PT S AU Restaino, SR Payne, D Anderson, M Baker, JT Serati, S Loos, GC AF Restaino, SR Payne, D Anderson, M Baker, JT Serati, S Loos, GC BE Bonaccini, D Tyson, RK TI Progress report on the USAF research laboratory liquid crystal AO program. SO ADAPTIVE OPTICAL SYSTEM TECHNOLOGIES, PARTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Adaptive Optical System Technologies CY MAR 23-26, 1998 CL KONA, HI SP SPIE, European So Observ DE adaptive optics; liquid crystals AB In this paper we present a status report of our liquid crystal (LC) adaptive optics program. Liquid crystal have been proposed to be used for adaptive optics components by several authors. We are actively persuing a two prong approach, on one side we have built a closed loop test bed based on a 127 element nematic LC device; on the other side we are actively involved in research on the ferroelectric side of the LC devices. In this paper we present preliminary results from our testeb. The essential elements of this testbed are a Shack-Hartmann based wavefront sensor with an analog reconstructor, and the 127 nematic elements from Meadowlark Optics. Some of the basic experimental parameters will be reviewed, and results will be discussed. Furthermore we will present the status of our activity in the field of ferroelectric LC. Several prototypes are under testing to establish their capabilities as AO components. C1 USAF, Res Lab, DEBS, Kirtland AFB, NM 87117 USA. RP Restaino, SR (reprint author), USAF, Res Lab, DEBS, Kirtland AFB, NM 87117 USA. NR 0 TC 10 Z9 10 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2800-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3353 BP 776 EP 781 DI 10.1117/12.321694 PG 6 WC Optics SC Optics GA BL80V UT WOS:000076793400084 ER PT S AU Cowan, WD Lee, MK Bright, VM Welsh, BM AF Cowan, WD Lee, MK Bright, VM Welsh, BM BE Bonaccini, D Tyson, RK TI Evaluation of microfabricated deformable mirror systems SO ADAPTIVE OPTICAL SYSTEM TECHNOLOGIES, PARTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Adaptive Optical System Technologies CY MAR 23-26, 1998 CL KONA, HI SP SPIE, European So Observ DE micro-electro-mechanical systems (MEMS); micromirrors; adaptive optics; beam steering; deformable mirrors AB This paper presents recent results for aberration correction and beam steering experiments using polysilicon surface micromachined piston micromirror arrays. Microfabricated deformable mirrors offer a substantial cost reduction for adaptive optic systems. In addition to the reduced mirror cost, microfabricated mirrors typically require low control voltages (less than 30 volts), thus eliminating high voltage amplifiers. The greatly reduced cost per channel of adaptive optic systems employing microfabricated deformable mirrors promise high order aberration correction at low cost. Arrays of piston micromirrors with 128 active elements were tested. Mirror elements are on a 203 mu m 12x12 square grid (with 16 inactive elements, 4 in each corner of the array). The overall array size is 2.4 mm square. The arrays were fabricated in the commercially available DARPA supported MUMPs surface micromachining foundry process. The cost per mirror array in this prototyping process is less than $200. Experimental results are presented for a hybrid correcting element comprised of a lenslet array and piston micromirror array, and for a piston micromirror array only. Also presented is a novel digital deflection micromirror which requires no digital to analog converters, further reducing the cost of adaptive optics systems. C1 USAF, Inst Technol, Dept Elect & Comp Engn, ENG,AFIT, Wright Patterson AFB, OH 45433 USA. RP Cowan, WD (reprint author), USAF, Inst Technol, Dept Elect & Comp Engn, ENG,AFIT, 2950 P St, Wright Patterson AFB, OH 45433 USA. NR 0 TC 6 Z9 6 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2800-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3353 BP 790 EP 804 DI 10.1117/12.321696 PG 15 WC Optics SC Optics GA BL80V UT WOS:000076793400086 ER PT S AU Michalicek, MA Clark, N Comtois, JH Schriner, HK AF Michalicek, MA Clark, N Comtois, JH Schriner, HK BE Bonaccini, D Tyson, RK TI Design and simulation of advanced surface micromachined micromirror devices for telescope adaptive optics applications SO ADAPTIVE OPTICAL SYSTEM TECHNOLOGIES, PARTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Adaptive Optical System Technologies CY MAR 23-26, 1998 CL KONA, HI SP SPIE, European So Observ DE MEMS; micromirrors; optical MEMS; MOEMS; CMP planarization; SUMMiT; adaptive optics; Strehl ratio AB This paper describes the design, fabrication, modeling, surface characterization, and simulation of advanced surface micromachined micromirror devices that are optimized for adaptive optics applications. Design considerations and fabrication capabilities are presented. Simulation of adaptive optics performance of unique Flexure-Beam (FBMD) and Axial-Rotation Micromirror Devices (ARMD) is performed for many common aberrations. These devices are fabricated in the state-of-the-art four-level planarized polysilicon process available at Sandia National Laboratories known as the Sandia Ultra-planar Multi-level MEMS Technology (SUMMiT). This enabling process permits the development of micromirror devices with near-ideal characteristics that have previously been unrealizable in standard three-layer polysilicon processes. This paper describes such characteristics as elevated address electrodes, array wiring techniques, planarized mirror surfaces using Chemical Mechanical Polishing (CMP), unique post-process metallization, and the best active surface area to date. C1 USAF, Res Lab, Kirtland AFB, NM 87117 USA. RP Michalicek, MA (reprint author), USAF, Res Lab, Kirtland AFB, NM 87117 USA. NR 0 TC 8 Z9 8 U1 0 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2800-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3353 BP 805 EP 815 DI 10.1117/12.321697 PG 11 WC Optics SC Optics GA BL80V UT WOS:000076793400087 ER PT S AU Christou, JC Marchis, F Ageorges, N Bonaccini, D Rigaut, F AF Christou, JC Marchis, F Ageorges, N Bonaccini, D Rigaut, F BE Bonaccini, D Tyson, RK TI Deconvolution of ADONIS images SO ADAPTIVE OPTICAL SYSTEM TECHNOLOGIES, PARTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Adaptive Optical System Technologies CY MAR 23-26, 1998 CL KONA, HI SP SPIE, European So Observ DE Adaptive Optics; astronomy; infrared imaging; image post processing; deconvolution; blind deconvolution AB Post processing of data obtained from the European Southern Observatory's ADONIS system is presented here. A physically constrained iterative deconvolution algorithm is applied to two distinctly different objects demonstrating both object and point spread function recovery. Surface features are found in thermal imaging of Io which compare well with Galileo measurements of vulcanism. Ansioplanatic behaviour of the ADONIS system is studied with wide field imaging of the cluster NGC1850. C1 USAF, Res Lab, DES, Starfire Opt Range, Kirtland AFB, NM 87117 USA. RP Christou, JC (reprint author), USAF, Res Lab, DES, Starfire Opt Range, 3550 Aberdeen Ave SE, Kirtland AFB, NM 87117 USA. RI Marchis, Franck/H-3971-2012 NR 0 TC 4 Z9 4 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2800-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3353 BP 984 EP 993 DI 10.1117/12.321719 PG 10 WC Optics SC Optics GA BL80V UT WOS:000076793400106 ER PT S AU Drummond, JD AF Drummond, JD BE Bonaccini, D Tyson, RK TI The adaptive optics Lorentzian point spread function SO ADAPTIVE OPTICAL SYSTEM TECHNOLOGIES, PARTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Adaptive Optical System Technologies CY MAR 23-26, 1998 CL KONA, HI SP SPIE, European So Observ DE adaptive optics; point spread function; image analysis; asteroids; vesta AB A Lorentzian shaped point spread function (PSF) for adaptive optics is demonstrated. In some cases, a Lorentz atop an Airy pattern is a better description of the PSF. If the object can also be described with an analytic function, then Parametric Blind Deconvolution can be applied as a self referencing method to extract information about both the object and PSF simultaneously. The technique is used to derive the triaxial shape and rotational pole of the asteroid Vesta from observations made on the night of October 18, 1997, marking the first time the high order loop was closed for science with the Starfire Optical Range's 3.5m telescope. C1 USAF, Res Lab, Starfire Opt Range, Kirtland AFB, NM 87117 USA. RP Drummond, JD (reprint author), USAF, Res Lab, Starfire Opt Range, Kirtland AFB, NM 87117 USA. NR 0 TC 11 Z9 11 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2800-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3353 BP 1030 EP 1037 DI 10.1117/12.321648 PG 8 WC Optics SC Optics GA BL80V UT WOS:000076793400111 ER PT S AU Montera, DA Ellerbroek, BL Brown, JM AF Montera, DA Ellerbroek, BL Brown, JM BE Bonaccini, D Tyson, RK TI A phase and slope screen generator for spatially and temporally correlated unlimited length sequences. SO ADAPTIVE OPTICAL SYSTEM TECHNOLOGIES, PARTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Adaptive Optical System Technologies CY MAR 23-26, 1998 CL KONA, HI SP SPIE, European So Observ DE phase screen generator; slope screen generator AB The ability to generate long sequences of spatially and temporally correlated phase and slope screens is critical to simulating adaptive optics systems. Covariance based methods exist for generating short sequences of phase and slope screens which theoretically could produce the long sequences needed. However, implementing these methods for large sequences of frames is impractical with today's computer technology. FFT-based methods may be used to generate unlimited-length sequences which are periodic. This paper presents a method for generating unlimited length sequences which are not periodic using optimal estimators. This method does not yield perfect spatial and temporal statistics for screens separated by large numbers of frames in time. However, the short term statistics for any frame are accurate, while the errors in long term statistics are small. C1 USAF, Res Lab, Starfire Opt Range, Kirtland AFB, NM 87117 USA. RP Montera, DA (reprint author), USAF, Res Lab, Starfire Opt Range, 3550 Aberdeen Ave SE, Kirtland AFB, NM 87117 USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2800-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3353 BP 1070 EP 1079 DI 10.1117/12.321729 PG 10 WC Optics SC Optics GA BL80V UT WOS:000076793400115 ER PT S AU Lee, D Ellerbroek, B Christou, J AF Lee, D Ellerbroek, B Christou, J BE Bonaccini, D Tyson, RK TI First results for the Starfire Optical Range 3.5m telescope adaptive optics system: Point-spread functions and tracking performance SO ADAPTIVE OPTICAL SYSTEM TECHNOLOGIES, PARTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Adaptive Optical System Technologies CY MAR 23-26, 1998 CL KONA, HI SP SPIE, European So Observ C1 USAF, Res Lab, DES, Starfire Opt Range, Kirtland AFB, NM 87117 USA. RP Lee, D (reprint author), USAF, Res Lab, DES, Starfire Opt Range, Kirtland AFB, NM 87117 USA. NR 0 TC 4 Z9 4 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2800-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3353 BP 1080 EP 1091 DI 10.1117/12.321730 PG 12 WC Optics SC Optics GA BL80V UT WOS:000076793400116 ER PT S AU Clark, N Furth, P Whitfield, G Comtois, J McKecknie, S Michalicek, A AF Clark, N Furth, P Whitfield, G Comtois, J McKecknie, S Michalicek, A BE Bonaccini, D Tyson, RK TI Silicon adaptive optics systems using micro-mirrors SO ADAPTIVE OPTICAL SYSTEM TECHNOLOGIES, PARTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Adaptive Optical System Technologies CY MAR 23-26, 1998 CL KONA, HI SP SPIE, European So Observ DE smart vision; adaptive optics; liquid crystals; and micro-mirrors; phase diversity; wavefront correction AB Many factors contribute to the aberrations induced in an optical system. Atmospheric turbulence between the object and the imaging system, physical or thermal perturbations in optical elements degrade the system's point spread function, and misaligned optics are the primary sources of aberrations that affect image quality. The design of a non-conventional real-time adaptive optic system using a micro-mirror device for wavefront correction is presented. The adaptive optic system uses a VLSI circuit that can be reconfigured for use with many wavefront sensors including the Hartmann, shearing, and curvature wavefront sensors. The unconventional adaptive optic imaging systems presented offer advantages in speed, cost, power consumption, and weight. Experimental and modeling results that characterizes the performance of each wavefront sensor in the micro-mirror adaptive optic system are presented. C1 USAF, Res Lab, Kirtland AFB, NM 87117 USA. RP Clark, N (reprint author), USAF, Res Lab, Kirtland AFB, NM 87117 USA. NR 0 TC 1 Z9 1 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2800-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3353 BP 1146 EP 1154 DI 10.1117/12.321665 PG 9 WC Optics SC Optics GA BL80V UT WOS:000076793400123 ER PT S AU Ellerbroek, BL Rhoadarmer, TA AF Ellerbroek, BL Rhoadarmer, TA BE Bonaccini, D Tyson, RK TI Real-time adaptive optimization of wave-front reconstruction algorithms for closed-loop adaptive-optical systems SO ADAPTIVE OPTICAL SYSTEM TECHNOLOGIES, PARTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Adaptive Optical System Technologies CY MAR 23-26, 1998 CL KONA, HI SP SPIE, European So Observ DE wavefront reconstruction; adaptive optics; recursive least squares AB In recent years several methods have been presented for optimizing closed-loop adaptive-optical (AO) wave-front reconstruction algorithms. These algorithms, which can significantly improve the performance of AO systems, compute the reconstruction matrix using measured atmospheric statistics. Since atmospheric conditions vary on time scales of minutes, it becomes necessary to constantly update the reconstructor so that it adjusts to the changing atmospheric statistics. This paper presents a method for adaptively optimizing the reconstructor of a closed-loop AO system in real time. The method relies on recursive least squares techniques to track the temporal and spatial correlations of the turbulent wave-front. The performance of this method is examined for a sample scenario in which the AO control algorithm attempts to compensate for signal processing latency by reconstructing the future value of the wave-front from a combination of past and current wave-front sensor measurements. For this case, the adaptive reconstruction algorithm yields Strehl ratios within a few per cent of those obtained by an optimal reconstructor derived from a priori knowledge of the strength of the turbulence and the velocity of the wind. This level of performance can be a dramatic improvement over the Strehls achievable with a conventional least squares reconstructor. C1 USAF, Res Lab, DES, Kirtland AFB, NM 87117 USA. RP Ellerbroek, BL (reprint author), USAF, Res Lab, DES, 3550 Aberdeen SE, Kirtland AFB, NM 87117 USA. NR 0 TC 24 Z9 24 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2800-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3353 BP 1174 EP 1185 DI 10.1117/12.321732 PG 12 WC Optics SC Optics GA BL80V UT WOS:000076793400126 ER PT J AU Ji, FS Dharani, LR Mall, S AF Ji, FS Dharani, LR Mall, S TI Analysis of transverse cracking in cross-ply composite laminates SO ADVANCED COMPOSITE MATERIALS LA English DT Article DE transverse cracking; stiffness; energy release rate; cross-ply laminates; critical stress; crack density ID MULTIPLE MATRIX CRACKING; STIFFNESS REDUCTION; GLASS; BEHAVIOR; POISSON; FATIGUE; STRAIN AB An analytical model based on the principle of minimum potential energy is developed and applied to determine the two-dimensional thermoelastic stress state in cross-ply composite laminates containing multiple equally spaced transverse cracks in the 90 degrees plies and subjected to tensile loading in the longitudinal direction. The model provides full field solution for displacements and stresses including the residual thermal stresses which in turn are used to calculate the strain energy release rate associated with various failure modes. The strain energy release rate criterion has been employed to evaluate the critical applied stresses for two of the possible fracture modes; self-similar extension of a pre-existing flaw and the formation of a new parallel crack. The computed results indicate that formation of new cracks never takes place until pre-existing cracks extend through the entire thickness of the 90 degrees plies. The predicted results of transverse crack density are in good agreement with the available experimental data. C1 Univ Missouri, Dept Mech & Aerosp Engn & Engn Mech, Rolla, MO 65409 USA. USAF, Inst Technol, Dept Aeronaut, Wright Patterson AFB, OH 45433 USA. RP Dharani, LR (reprint author), Univ Missouri, Dept Mech & Aerosp Engn & Engn Mech, Rolla, MO 65409 USA. NR 32 TC 8 Z9 9 U1 1 U2 3 PU VSP BV PI ZEIST PA PO BOX 346, 3700 AH ZEIST, NETHERLANDS SN 0924-3046 J9 ADV COMPOS MATER JI Adv. Compos. Mater. PY 1998 VL 7 IS 1 BP 83 EP 103 DI 10.1163/156855198X00075 PG 21 WC Materials Science, Composites SC Materials Science GA ZA500 UT WOS:000072369500007 ER PT S AU Craig, AE AF Craig, AE BE Mitkas, PA Hasan, ZU TI Direction in optical storage SO ADVANCED OPTICAL MEMORIES AND INTERFACES TO COMPUTER STORAGE SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Advanced Optical Memories and Interfaces to Computer Storage CY JUL 22-24, 1998 CL SAN DIEGO, CA SP SPIE Int Soc Opt Engn AB Data communication aggregate bandwidth now doubles every 100 days. This transmitted data has origins and destinations, as well as way-stations. At terabit per second channel bandwidth, new optical memory technology may enhance the capability to launch, buffer, and collect multiplexed data streams in the optical domain. Candidate technologies include soliton fiber-loop and coherent transient memories. C1 AF Off Sci Res, Bolling AFB, DC 20332 USA. RP Craig, AE (reprint author), AF Off Sci Res, Bolling AFB, DC 20332 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2923-6 J9 P SOC PHOTO-OPT INS PY 1998 VL 3468 BP 96 EP 100 DI 10.1117/12.330406 PG 5 WC Computer Science, Hardware & Architecture; Optics SC Computer Science; Optics GA BM20R UT WOS:000078029300012 ER PT S AU Thai, S Song, QW AF Thai, S Song, QW BE Mitkas, PA Hasan, ZU TI Transient diffraction efficiency of a D96N mutant bacteriorhodopsin film SO ADVANCED OPTICAL MEMORIES AND INTERFACES TO COMPUTER STORAGE SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Advanced Optical Memories and Interfaces to Computer Storage CY JUL 22-24, 1998 CL SAN DIEGO, CA SP SPIE Int Soc Opt Engn DE three laser beam technique; laser-induced transient gratings; D96N mutant bacteriorhodopsin film AB A three-laser-beam technique is developed to study the transient diffraction efficiency of M-state dynamic phase holograms in a D96N mutant bacteriorhodopsin film (BR). A CW beam from 532 nm doubled Nd: YAD laser is used to pump BR molecules from B-state to photoexcited M-state. Then the M-state absorption laser 413-nm wavelength from a Krypton Ion laser is used to write holographic gratings in the excited M-state. The writing process also depletes M-molar concentrations. This process offers the advantages of better modulation and faster response. The reading is done with a 680 nm laser, which is far away from the absorption bands to ensure a negligible erasing effect on the gratings written in the film, resulting a pure phase hologram with high efficiency. A maximized transient peak diffraction efficiency approaches a saturated value when the ratio of write to pump intensity is approximately unity. C1 USAF, Res Lab, SNDP, Rome, NY 13441 USA. RP Thai, S (reprint author), USAF, Res Lab, SNDP, 25 Elect Pkwy, Rome, NY 13441 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2923-6 J9 P SOC PHOTO-OPT INS PY 1998 VL 3468 BP 206 EP 214 DI 10.1117/12.330419 PG 9 WC Computer Science, Hardware & Architecture; Optics SC Computer Science; Optics GA BM20R UT WOS:000078029300024 ER PT B AU Hunt, BW Stevens, KS Suter, BW Gelosh, DS AF Hunt, BW Stevens, KS Suter, BW Gelosh, DS GP IEEE, COMP SOC TI A single chip low power asynchronous implementation of an FFT algorithm for space applications SO ADVANCED RESEARCH IN ASYNCHRONOUS CIRCUITS AND SYSTEMS - FOURTH INTERNATIONAL SYMPOSIUM LA English DT Proceedings Paper CT 4th International Symposium on Advanced Research in Asynchronous Circuits and Systems CY MAR 30-APR 02, 1998 CL SAN DIEGO, CA SP IEEE, Comp Soc, Tech Comm VLSI, Univ Calif, INTEL Corp AB A fully asynchronous fixed point FFT processor is introduced for low power space applications. The architecture is based on an algorithm developed by Suter and Stevens specifically for a low power implementation. The novelty of this architecture lies in its high localization of components and pipelining with no need to share a global memory. High throughput is attained using large numbers of small, local components working in parallel. A derivation of the algorithm from the discrete Fourier transform is presented followed by a discussion of circuit design parameters specifically those relevant to space applications. A survey of this application specific architecture is included with a detailed look at the design of the complex-valued Booth multiplier to demonstrate the design methodology of this project. Finally, simulation results based on layout extractions are presented and an outline for future work is given. C1 USAF, Inst Technol, Dept Elect & Comp Engn, Wright Patterson AFB, OH 45433 USA. RP Hunt, BW (reprint author), USAF, Inst Technol, Dept Elect & Comp Engn, Wright Patterson AFB, OH 45433 USA. NR 0 TC 4 Z9 4 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA BN 0-8186-8392-9 PY 1998 BP 216 EP 223 DI 10.1109/ASYNC.1998.666507 PG 8 WC Computer Science, Hardware & Architecture; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BK78T UT WOS:000073380500018 ER PT S AU Suter, BW Stevens, KS AF Suter, BW Stevens, KS BE Luk, FT TI A low power, high performance approach for time-frequency/time-scale computations SO ADVANCED SIGNAL PROCESSING ALGORITHMS, ARCHITECTURES, AND IMPLEMENTATIONS VIII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Advanced Signal Processing Algorithms, Architectures, and Implementations VIII CY JUL 22-24, 1998 CL SAN DIEGO, CA SP SPIE DE time-frequency computations; time-scale computations; asynchronous circuit design; multirate signal processing; generalized distributive law; fast Fourier transform AB This paper presents an application of formal mathematics to create a high performance, low power architecture for time-frequency and time-scale computations implemented in asynchronous circuit technology that achieves significant power reductions and performance enhancements over more traditional approaches. Utilizing a combination of concepts from multirate signal processing and asynchronous circuit design, a case study is presented dealing with a new architecture for the fast Fourier transform, an algorithm that requires globally shared results. Then, the generalized distributive law is presented as an important paradigm for advanced asynchronous hardware design. C1 USAF, Res Lab, IFGC, Griffiss AFB, NY 13441 USA. RP Suter, BW (reprint author), USAF, Res Lab, IFGC, 525 Brooks Rd, Griffiss AFB, NY 13441 USA. NR 0 TC 6 Z9 6 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2916-3 J9 P SOC PHOTO-OPT INS PY 1998 VL 3461 BP 86 EP 90 DI 10.1117/12.325727 PG 5 WC Engineering, Electrical & Electronic SC Engineering GA BL81C UT WOS:000076796000009 ER PT S AU Varanasi, C Biggers, RR Maartense, I Dempsey, D Peterson, TL Solomon, J McDaniel, J Kozlowski, G Nekkanti, R Oberly, CE AF Varanasi, C Biggers, RR Maartense, I Dempsey, D Peterson, TL Solomon, J McDaniel, J Kozlowski, G Nekkanti, R Oberly, CE BE Singh, RK Lowndes, DH Chrisey, DB Fogarassy, E Narayan, J TI Pulsed laser deposition of Nd-doped YBa2Cu3O7-x films for coated conductor applications SO ADVANCES IN LASER ABLATION OF MATERIALS SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Advances in Laser Ablation of Materials at the 1998 MRS Spring Meeting CY APR 13-16, 1998 CL SAN FRANCISCO, CA SP Mat Res Soc (MRS) AB Pulsed-laser ablation was used to deposit YBa2Cu3O7-x (YBCO) films on LaAlO3 and metallic substrates in an effort to understand and develop the processing of coated conductors with enhanced properties. Doping of YBCO films with Nd was utilized as an approach for increasing their flux pinning properties. Separate targets of Nd2O3 and YBCO were used instead of a pre-mixed Nd2O3-YBCO target. The critical current density (J(c)) of the films was measured by whole body de transport measurements and the transition temperature (T-c) by ac susceptibility. The composition vs. depth profiles of the films were obtained by Secondary Ion Mass Spectrometry. The critical current of a 5000 Angstrom thick Nd-doped YBCO film on a LaAlO3 substrate was measured at 77 K and found to be 57 A (J(c) = 1.1 x 10(6) A/cm(2)). C1 USAF, Res Lab, Wright Patterson AFB, OH 45433 USA. RP Varanasi, C (reprint author), USAF, Res Lab, Wright Patterson AFB, OH 45433 USA. NR 0 TC 5 Z9 5 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-432-7 J9 MATER RES SOC SYMP P PY 1998 VL 526 BP 263 EP 268 PG 6 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Optics SC Materials Science; Optics GA BM12Q UT WOS:000077696000039 ER PT S AU Culpepper, MA Metz, JP Stapp, JL AF Culpepper, MA Metz, JP Stapp, JL BE Khounsary, AM TI Liquid-cooled transmissive optical component SO ADVANCES IN MIRROR TECHNOLOGY FOR SYNCHROTRON X-RAY AND LASER APPLICATIONS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Advances in Mirror Technology for Synchrotron X-Ray and Laser Applications CY JUL 20, 1998 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers DE optical components; high-energy lasers; windows; cooled optics; optical contact bonding; optical liquids AB The objective of this project is to develop a liquid-cooled window to transmit a high-energy (HEL) laser beam. The window is to be used with continuous wave lasers with wavelengths between 1.0 - 1.4 mu m and is to be 20 or more centimeters in diameter. The window must transmit the beam with only small phase and amplitude distortions. The goal is less than 1/20 wave distortion across the beam at 1.315 mu m that is the primary wavelength of interest. A prototype window will be built at a later date. In this paper results are presented of research into a) techniques for bonding two pieces of fused silica to form the window and b) suitable coolants. C1 USAF, Res Lab, Kirtland AFB, NM 87117 USA. RP Culpepper, MA (reprint author), USAF, Res Lab, Kirtland AFB, NM 87117 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2902-3 J9 P SOC PHOTO-OPT INS PY 1998 VL 3447 BP 54 EP 61 DI 10.1117/12.331129 PG 8 WC Optics SC Optics GA BM20A UT WOS:000078011100006 ER PT S AU McDaniel, JW AF McDaniel, JW BE Kumar, S TI Design requirements for human strength: Asking the right question SO ADVANCES IN OCCUPATIONAL ERGONOMICS AND SAFETY, VOL 2 SE ADVANCES IN OCCUPATIONAL ERGONOMICS AND SAFETY LA English DT Proceedings Paper CT XIIIth Annual International Occupational Ergonomics and Safety Conference CY JUN 11-14, 1998 CL YPSILANTI, MI AB Due to erroneous assumptions and misunderstanding of ergonomics terminology, equipment designers invariably ask the wrong question when initiating a consultation. Beginning in the wrong direction is not only wasteful, but may lead to erroneous conclusions. Because human strength is task specific, a consulting ergonomist should first perform a detailed requirements analysis to help the designer understand the task the human will be asked to perform. Because measures of human characteristics are better known than measures of the human performance, they may be erroneously applied. The complex interacting factors of strength performance are discussed and guidance is given. C1 USAF, Res Lab, AFRL, HECP, Wright Patterson AFB, OH 45433 USA. RP McDaniel, JW (reprint author), USAF, Res Lab, AFRL, HECP, Wright Patterson AFB, OH 45433 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU I O S PRESS PI AMSTERDAM PA NIEUWE HEMWEG 6B, 1013 BG AMSTERDAM, NETHERLANDS SN 1384-2269 BN 90-5199-393-5 J9 ADV OCCUP ERGO SAF PY 1998 VL 2 BP 345 EP 348 PG 4 WC Engineering, Industrial; Ergonomics; Public, Environmental & Occupational Health; Rehabilitation SC Engineering; Public, Environmental & Occupational Health; Rehabilitation GA BL57P UT WOS:000075917700082 ER PT J AU Rizzetta, DP AF Rizzetta, DP TI Evaluation of explicit algebraic Reynolds-stress models for separated supersonic flows SO AIAA JOURNAL LA English DT Article; Proceedings Paper CT AIAA 28th Fluid Dynamics Conference CY JUN 29-JUL 02, 1997 CL SNOWMASS VILLAGE, CO SP Amer Inst Aeronaut & Astronaut ID BOUNDARY-LAYER INTERACTION; NUMERICAL-SIMULATION; 2-EQUATION MODEL; TURBULENT FLOWS; PREDICTION; EQUATION; SCHEME AB High-Reynolds number supersonic flowfields were generated numerically to assess the performance of three explicit algebraic Reynolds-stress turbulence models. The configurations consist of a shock/boundary-layer interaction and a 24-deg compression ramp, both of which exhibit an appreciable region of separated how Solutions were also obtained using standard zero-equation and k-epsilon models. Details of the computations are summarized, and the accuracy of numerical results is established via grid resolution studies. Comparisons are made with experimental data in terms of surface pressure and skin friction, as well as off-surface profiles of mean velocity and components of the Reynolds-stress tenser. For the flows considered here, it is found that the algebraic-stress models offer little improvement over existing closures. C1 USAF, Res Lab, Computat Fluid Dynam Res Branch, Aeromech Div, Wright Patterson AFB, OH 45433 USA. RP USAF, Res Lab, Computat Fluid Dynam Res Branch, Aeromech Div, Wright Patterson AFB, OH 45433 USA. NR 38 TC 10 Z9 10 U1 0 U2 4 PU AMER INST AERONAUTICS ASTRONAUTICS PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0001-1452 EI 1533-385X J9 AIAA J JI AIAA J. PD JAN PY 1998 VL 36 IS 1 BP 24 EP 30 DI 10.2514/2.370 PG 7 WC Engineering, Aerospace SC Engineering GA YR192 UT WOS:000071470000003 ER PT J AU Gaitonde, D Shang, JS AF Gaitonde, D Shang, JS TI Shock pattern of a triple-shock turbulent interaction SO AIAA JOURNAL LA English DT Article C1 USAF, Wright Lab, Wright Patterson AFB, OH 45433 USA. NR 4 TC 2 Z9 2 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0001-1452 J9 AIAA J JI AIAA J. PD JAN PY 1998 VL 36 IS 1 BP 113 EP 115 DI 10.2514/2.362 PG 3 WC Engineering, Aerospace SC Engineering GA YR192 UT WOS:000071470000017 ER PT S AU Kelchner, BL Dauk, R AF Kelchner, BL Dauk, R BE Steiner, TD Merritt, PH TI ABL beam control segment SO AIRBORNE LASER ADVANCED TECHNOLOGY SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Airborne Laser Advanced Technology CY APR 13-14, 1998 CL ORLANDO, FL SP SPIE Int Soc Opt Engn DE ABL; beam control; fire control; high energy lasers; illuminator lasers; ATP AB The U.S. Air Force Airborne Laser (ABL) consists of four primary subsystem segments; aircraft, battle management and C4I, laser device, and beam control segment(BCS). The BCS performs two major function, beam control and fire control, using three primary products, turret assembly, beam transfer assembly, and fire control hardware and software. The fire control sequence involves slewing the turret to the target coordinates as received from the battle management segment, centering the target in the acquisition sensor, acquiring the plume in the coarse track sensor, acquiring the hard body of the missile with the track illuminator laser (TILL), and establishing active tracking of the nose of the target theater ballistic missile. The beam control sequence begins after established active nose track by firing another beacon illuminator laser (BILL) to establish the aim point on the missile for the high energy laser. The resulting spot on the missile is imaged in the wavefront sensor and compared with the outgoing sample of the BILL. By applying the conjugate of the wavefront difference from the beacon to a deformable mirror then the atmosphere serves to correct the arriving wavefront on target. At this point the HEL is fired along the same path with similar wavefront correction, and dwells on target until the missile skin is weakened and rips open or buckles. C1 USAF, Space & Missile Ctr, Airborne Laser Syst Program Off, Kirtland AFB, NM 87117 USA. RP Kelchner, BL (reprint author), USAF, Space & Missile Ctr, Airborne Laser Syst Program Off, Kirtland AFB, NM 87117 USA. NR 0 TC 2 Z9 2 U1 1 U2 3 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2830-2 J9 P SOC PHOTO-OPT INS PY 1998 VL 3381 BP 8 EP 13 DI 10.1117/12.323934 PG 4 WC Engineering, Aerospace; Optics SC Engineering; Optics GA BL83Q UT WOS:000076893600002 ER PT S AU Steiner, TD Butts, RR Kramer, MA AF Steiner, TD Butts, RR Kramer, MA BE Steiner, TD Merritt, PH TI Airborne Laser Advanced Concepts Testbed SO AIRBORNE LASER ADVANCED TECHNOLOGY SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Airborne Laser Advanced Technology CY APR 13-14, 1998 CL ORLANDO, FL SP SPIE Int Soc Opt Engn AB The Airborne Laser Advanced Concepts Testbed (ABL ACT) is a low power beam control testbed located at the northern end of White Sands Missile Range. The purpose of ABL ACT is to explore advanced beam control concepts for laser propagation under high scintillation conditions. This paper gives the capabilities of the system and subsystem that are in place or will be in place within the next year. C1 USAF, Res Lab, Directorate Energy Directorate, Airborne Laser Technol Branch, Kirtland AFB, NM 87117 USA. RP Steiner, TD (reprint author), USAF, Res Lab, Directorate Energy Directorate, Airborne Laser Technol Branch, Kirtland AFB, NM 87117 USA. NR 0 TC 4 Z9 4 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2830-2 J9 P SOC PHOTO-OPT INS PY 1998 VL 3381 BP 23 EP 27 DI 10.1117/12.323951 PG 5 WC Engineering, Aerospace; Optics SC Engineering; Optics GA BL83Q UT WOS:000076893600004 ER PT S AU Browning, WM Olson, DS Keenan, DE AF Browning, WM Olson, DS Keenan, DE BE Steiner, TD Merritt, PH TI High Altitude Balloon Experiment SO AIRBORNE LASER ADVANCED TECHNOLOGY SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Airborne Laser Advanced Technology CY APR 13-14, 1998 CL ORLANDO, FL SP SPIE Int Soc Opt Engn DE acquisition; tracking and pointing; space-based lasers AB The mission of the High Altitude Balloon Experiment (HABE) is to resolve critical acquisition, tracking, and pointing (ATP) and fire control issues, validate enabling technologies, and acquire supporting data for future space-based lasers (SBL)experiments. HABE is integrating components from existing technologies into a payload that can autonomously acquire, track, and point a low power laser at a ballistic missile in its boost phase of flight. For its primary mission the payload will be flown multiple times to an altitude of 85,000 feet above the White Sands Missile Range ((WSMR). From the near-space environment of the balloon flight, HABE will demonstrate the ATP functions required for a space-based laser in a ballistic missile defense role. The HABE platform includes coarse and fine gimbal pointing, infrared and visible passive tracking, active fine tracking, internal auto-alignment and boresighting, and precision line-of-sight (LOS) stabilization functions. This paper presents an overview and status of the HABE program. C1 USAF, Res Lab, Kirtland AFB, NM 87117 USA. RP Browning, WM (reprint author), USAF, Res Lab, Kirtland AFB, NM 87117 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2830-2 J9 P SOC PHOTO-OPT INS PY 1998 VL 3381 BP 28 EP 36 DI 10.1117/12.323952 PG 5 WC Engineering, Aerospace; Optics SC Engineering; Optics GA BL83Q UT WOS:000076893600005 ER PT S AU Oppenheimer, MW Pachter, M AF Oppenheimer, MW Pachter, M BE Steiner, TD Merritt, PH TI The statistics of the beacon and high energy laser wavefronts in the AirBorne Laser SO AIRBORNE LASER ADVANCED TECHNOLOGY SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Airborne Laser Advanced Technology CY APR 13-14, 1998 CL ORLANDO, FL SP SPIE Int Soc Opt Engn DE adaptive optics; AirBorne Laser; novel frozen flow hypothesis AB In this work, the application of adaptive optics to the AirBorne Laser is considered. The objective is to determine the statistics of the Zernike polynomial coefficients of the phase of the beacon and high energy laser wavefronts. The: process of determining the covariance matrix of the phase expansion coefficients of the inbound (beacon) and outbound (high energy laser) wavefront phases is outlined. This work differs from previous research in that it exclusively focuses on the AirBorne Laser (ABL) engagement kinematics. Specifically, the temporal dependence of the above mentioned covariance matrix is determined with appropriate modifications to previous work. Atmospheric wind is neglected due to the large virtual wind induced by the aperture and target velocities. This requires that Taylor's frozen flow hypothesis be modified. Moreover, due to the finite distance between the receiving/transmitting apertures and the target, spherical wavefronts must be used throughout the development. C1 USAF, Inst Technol, Dept Elect & Comp Engn, Wright Patterson AFB, OH 45433 USA. RP Oppenheimer, MW (reprint author), USAF, Inst Technol, Dept Elect & Comp Engn, 2950 P St,Bldg 640, Wright Patterson AFB, OH 45433 USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2830-2 J9 P SOC PHOTO-OPT INS PY 1998 VL 3381 BP 88 EP 97 DI 10.1117/12.323928 PG 4 WC Engineering, Aerospace; Optics SC Engineering; Optics GA BL83Q UT WOS:000076893600011 ER PT S AU Whiteley, MR Roggemann, MC Welsh, BM AF Whiteley, MR Roggemann, MC Welsh, BM BE Steiner, TD Merritt, PH TI Optimal beam steering using time-delayed wavefront measurements in Airborne Laser target engagements SO AIRBORNE LASER ADVANCED TECHNOLOGY SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Airborne Laser Advanced Technology CY APR 13-14, 1998 CL ORLANDO, FL SP SPIE Int Soc Opt Engn DE atmospheric optics; adaptive optics; tilt compensation; beam steering AB In Airborne Laser (ABL) target engagements, beam steering should account for the effects of turbulence-induced wavefront tilt. Due to the finite temporal response of adaptive-optical systems, steering commands must be based upon time-delayed wavefront measurements. The dynamics of the ABL target engagement scenario and turbulence-induced anisoplanatism cause the time-delayed wavefront measurements to be decorrelated from the required wavefront tilt correction. This decorrelation leads to suboptimal beam steering when time-delayed wavefront measurements are used directly in the control loop. To assess beam steering performance, we calculate the aperture-averaged mean square residual phase error after tilt correction, as a function of measurement time delay, and show that this quantity is minimized by the minimum mean square error (MMSE) estimate of tilt given a set of time-delayed wavefront measurements. Therefore, a temporal MMSE tilt estimator is constructed using time-delayed tilt plus higher-order aberration measurements. We define the tilt correction interval tau(c) as the time delay at which the residual phase error is 1% larger than its value at zero time delay. Our results show that tau(c) using the MMSE tilt estimator with modal measurements through Zernike 15 is over 3 times larger than tau(c) using time-delayed tilt measurements only. Accordingly, the beam steering bandwidth for ABL target engagements is reduced by more than 70% when higher order modal measurements are used in optimal tilt correction. C1 USAF, Inst Technol, Dept Engn Phys, Wright Patterson AFB, OH 45433 USA. RP Welsh, BM (reprint author), USAF, Inst Technol, Dept Engn Phys, 2950 P St,Bldg 640, Wright Patterson AFB, OH 45433 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2830-2 J9 P SOC PHOTO-OPT INS PY 1998 VL 3381 BP 98 EP 109 DI 10.1117/12.323929 PG 4 WC Engineering, Aerospace; Optics SC Engineering; Optics GA BL83Q UT WOS:000076893600012 ER PT S AU Whiteley, MR Gardner, PJ AF Whiteley, MR Gardner, PJ BE Steiner, TD Merritt, PH TI Experimental measurement of tilt correlation with higher-order modes in the time domain for turbulence-induced phase aberrations; implications to Airborne Laser beam steering SO AIRBORNE LASER ADVANCED TECHNOLOGY SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Airborne Laser Advanced Technology CY APR 13-14, 1998 CL ORLANDO, FL SP SPIE Int Soc Opt Engn DE atmospheric optics; turbulence; tilt compensation; adaptive optics; airborne laser AB Theoretical analysis of the temporal cross-correlation properties of turbulence-induced phase aberrations predict that while tilt is uncorrelated with most higher-order modes at zero time delay, the magnitude of the cross-correlation increases through some maximum value before going to zero at long time delays. To test this theoretical prediction, we employ laboratory measurements of phase induced on a laser beam propagating through a channeled flow of turbulent gas. From these measurements, the temporal cross-correlation of various aberration modes was estimated. Theoretical expressions were derived for these cross-correlations, and the results of these calculations agree well with experimental measurements. Both the experimental and the theoretical results demonstrate that the magnitude of cross-correlation between tilt and higher-order modes is non-zero over a range of temporal delay. Thus, higher-order modal measurements may be incorporated into an optimal estimator for tilt, enhancing estimator performance. C1 USAF, Inst Technol, Dept Engn Phys, Wright Patterson AFB, OH 45433 USA. RP Whiteley, MR (reprint author), USAF, Inst Technol, Dept Engn Phys, 2950 P St,Bldg 640, Wright Patterson AFB, OH 45433 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2830-2 J9 P SOC PHOTO-OPT INS PY 1998 VL 3381 BP 110 EP 120 DI 10.1117/12.323930 PG 5 WC Engineering, Aerospace; Optics SC Engineering; Optics GA BL83Q UT WOS:000076893600013 ER PT S AU Venet, BP AF Venet, BP BE Steiner, TD Merritt, PH TI Optical scintillometry over a long, elevated horizontal path SO AIRBORNE LASER ADVANCED TECHNOLOGY SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Airborne Laser Advanced Technology CY APR 13-14, 1998 CL ORLANDO, FL SP SPIE Int Soc Opt Engn DE atmospheric turbulence; turbulence measurement; scintillation; irradiance variance; intensity variance AB We report scintillometer measurements for near-infrared propagation over a 51.4-km path, at an average altitude of 760 m over mountainous desert terrain. We present time series and histograms of normalized irradiance variance and path-averaged C-n(2) values. We compare the results with an average vertical C-n(2) profile constructed from past balloon measurements. We also present preliminary results on the temporal power spectra of normalized irradiance. C1 USAF, Res Lab, DEBA, Kirtland AFB, NM 87117 USA. RP Venet, BP (reprint author), USAF, Res Lab, DEBA, 3550 Aberdeen Ave SE, Kirtland AFB, NM 87117 USA. NR 0 TC 3 Z9 3 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2830-2 J9 P SOC PHOTO-OPT INS PY 1998 VL 3381 BP 212 EP 219 DI 10.1117/12.323942 PG 4 WC Engineering, Aerospace; Optics SC Engineering; Optics GA BL83Q UT WOS:000076893600023 ER PT S AU Eaton, FD Nastrom, GD Masson, B Hahn, I McCrae, K Nowlin, SR Berkopec, T AF Eaton, FD Nastrom, GD Masson, B Hahn, I McCrae, K Nowlin, SR Berkopec, T BE Steiner, TD Merritt, PH TI Radar and aircraft observations of a layer of strong refractivity turbulence SO AIRBORNE LASER ADVANCED TECHNOLOGY SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Airborne Laser Advanced Technology CY APR 13-14, 1998 CL ORLANDO, FL SP SPIE Int Soc Opt Engn DE refractive index structure parameter; VHF radar observations; aircraft observations; turbulent atmospheric layers; persistent layers AB The Air Force Research Laboratory at Kirtland Air Force Base examined the characteristics of the refractive index structure parameter (C-n(2)) within a strong and persistent layer of turbulence using observations obtained from a 49.25 MHz radar and an instrumented C-135E aircraft at the Atmospheric Profiler Research Facility at White Sands Missile Range, NM on January 23,1997. The aircraft measurements sensed the atmospheric temperature structure parameter (C-T(2)) with fine-wire aerothermal probes for deriving C-n(2) while the radar measurements provided C-n(2) from Bragg scatter at turbulent scales in the clear air. The aircraft results provide horizontal spatial information at the specific altitudes flown while the radar-obtained values show temporal profile information. Flight legs approximately 200 km long were flown along the wind direction at eight different altitudes from 11.01 km to 12.21 km MSL. The turbulent layer and direction of flights were selected from the VHF radar-obtained C-n(2) and wind measurements prior to take-off. Presentations include a range-height display of the patterns of refractivity turbulence obtained from the aircraft measurements and a range-height display derived from the radar observations corresponding to the aircraft results. Both range-height displays were produced by assuming Taylor's hypothesis and applying the actual wind profile to the time-height data. The evolution and persistency of features is discussed. A statistical evaluation comparing the two different methods of sensing C-n(2) is presented. Salient features of the aircraft sensors and radar are discussed. C1 USAF, Res Lab, Kirtland AFB, NM 87117 USA. RP Eaton, FD (reprint author), USAF, Res Lab, Kirtland AFB, NM 87117 USA. NR 0 TC 4 Z9 4 U1 2 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2830-2 J9 P SOC PHOTO-OPT INS PY 1998 VL 3381 BP 230 EP 238 DI 10.1117/12.323944 PG 5 WC Engineering, Aerospace; Optics SC Engineering; Optics GA BL83Q UT WOS:000076893600025 ER PT S AU Weaver, LD AF Weaver, LD BE Steiner, TD Merritt, PH TI Saturation resistant optical turbulence sensor SO AIRBORNE LASER ADVANCED TECHNOLOGY SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Airborne Laser Advanced Technology CY APR 13-14, 1998 CL ORLANDO, FL SP SPIE Int Soc Opt Engn DE scintillation; turbulence sensor; laser propagation AB The optical measurement of atmospheric turbulence strength is often subject to the effects of scintillation saturation. In the saturation regime, the intensity variance no longer increases with turbulence strength. In some instances, the observed behavior with respect to turbulence strength shows a flattening of the variance followed by a shallow drop-off with further increases in turbulence. The Air Force Research Laboratory requires a robust instrument for determining path-integrated turbulence effects on a laser propagating over a 50 km path under a variety of clear-air atmospheric conditions and turbulence strengths. The approach described here is based on the measurement of the Mutual Coherence Function (MCF). The MCF doesn't saturate since it depends on the total wave structure function, a function consisting of a non-saturating phase term as well as the saturating log-amplitude term. The sensor itself is an interferometer which measures fringe visibility. In addition to a measure of turbulence strength, or C-n(2,) the wave structure function itself can be determined. The latter feature is an especially important one for determining whether or not Kolmogorov statistics prevail. C1 USAF, Res Lab, Kirtland AFB, NM 87117 USA. RP Weaver, LD (reprint author), USAF, Res Lab, Kirtland AFB, NM 87117 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2830-2 J9 P SOC PHOTO-OPT INS PY 1998 VL 3381 BP 268 EP 272 DI 10.1117/12.323948 PG 5 WC Engineering, Aerospace; Optics SC Engineering; Optics GA BL83Q UT WOS:000076893600029 ER PT S AU Hajek, DL Whiteley, MR AF Hajek, DL Whiteley, MR BE Steiner, TD Merritt, PH TI Relating turbulence parameters to synoptic scale meteorological data for Airborne Laser performance modeling SO AIRBORNE LASER ADVANCED TECHNOLOGY SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Airborne Laser Advanced Technology CY APR 13-14, 1998 CL ORLANDO, FL SP SPIE Int Soc Opt Engn DE optical turbulence; refractivity structure parameter; atmospheric refractive index; regression analysis AB The refractivity structure parameter C-n(2) characterizes the strength of refractive index fluctuations in the propagation path of; electromagnetic waves and specifies the magnitude of the spatial power spectral density of turbulence-induced phase aberrations. In addition, the integrated value of C-n(2) along the propagation path determines the performance of the adaptive optical system. In this study, we explore the statistical relationship between the refractivity structure parameter and synoptic scale meteorological measurements. To this end, we have employed simultaneous measurements of the structure constant and meteorological data associated with fronts and jet streams at the synoptic scale. Using linear regression techniques, the degree of association between the meteorological data and radar-observed structure parameter values was computed. The parameters most strongly related to the structure constant are indicated; however, further research is needed to define the exact relationship between the refractivity structure constant and synoptic-scale meteorological data. C1 USAF, Inst Technol, Dept Engn Phys, Wright Patterson AFB, OH 45433 USA. RP Hajek, DL (reprint author), USAF, Inst Technol, Dept Engn Phys, 2950 P St, Wright Patterson AFB, OH 45433 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2830-2 J9 P SOC PHOTO-OPT INS PY 1998 VL 3381 BP 273 EP 283 DI 10.1117/12.323949 PG 5 WC Engineering, Aerospace; Optics SC Engineering; Optics GA BL83Q UT WOS:000076893600030 ER PT S AU Louthain, JA Welsh, BM AF Louthain, JA Welsh, BM BE Steiner, TD Merritt, PH TI Fourier series based phase and amplitude optical field screen generator for weak atmospheric turbulence SO AIRBORNE LASER ADVANCED TECHNOLOGY SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Airborne Laser Advanced Technology CY APR 13-14, 1998 CL ORLANDO, FL SP SPIE Int Soc Opt Engn DE adaptive optics; atmospheric optics; atmospheric turbulence AB A new atmospheric screen generator is developed for use in performance calculations of adaptive optics and imaging systems. The generator is valid over a aide range of atmospheric turbulence parameters and incorporates both phase and amplitude effects. The nem screen generator accounts for diffraction effects caused by turbulence and incorporates the phase, amplitude, and cross statistics of a weak turbulence model. The second order statistics of the phase and amplitude perturbations are based on the auto-correlation functions developed by Lee and Harp and the cross-correlation of the phase and amplitude perturbations derived in this paper. The correlations are derived by modeling the turbulence as a number of layers of randomly varying refractivity perpendicular to the propagation path. As the field propagates through the medium, diffraction occurs at each of the lasers. A Fourier series expansion of the wavefront phase and amplitude is used. The screen generator uses the power and cross spectral densities of the phase and amplitude perturbations. The mean square value and the structure functions of the wavefront phase and amplitude are calculated in a Monte Carlo experiment and shown to be within 1% of the theoretical values. C1 USAF, Inst Technol, Dept Elect & Comp Engn, Wright Patterson AFB, OH 45433 USA. RP Louthain, JA (reprint author), USAF, Inst Technol, Dept Elect & Comp Engn, 2950 P St,Bldg 640, Wright Patterson AFB, OH 45433 USA. NR 0 TC 7 Z9 7 U1 1 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2830-2 J9 P SOC PHOTO-OPT INS PY 1998 VL 3381 BP 286 EP 296 DI 10.1117/12.323950 PG 5 WC Engineering, Aerospace; Optics SC Engineering; Optics GA BL83Q UT WOS:000076893600031 ER PT S AU Power, GJ Karim, MA AF Power, GJ Karim, MA BE Fishell, WG Andraitis, AA Fagan, MS Greer, JD Norton, MC TI Automatic removal of poor quality images from digital image sequences SO AIRBORNE RECONNAISSANCE XXII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT XXII Conference on Airborne Reconnaissance CY JUL 21-22, 1998 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers DE target recognition; image quality; spatio-temporal analysis; digital transmission; image sequence; recce subsystem; reconnaissance; velocital AB This paper introduces a spatio-temporal technique for selecting or filtering out lower quality digital image frames. The technique is demonstrated on Electro-Optical/Infrared image sequences which suggests it is a candidate for exploiting reconnaissance (recce) imagery or can be part of a recce subsystem. For human vision exploitation, a few poor quality image frames out of hundreds in a digital image sequence may be only a minor irritation when the sequence runs at the typical 30 frames per second. Of course, if that human needs to examine each frame, a system that automatically removes or enhances lower quality image frames could be beneficial. For machine vision subsystems, a few poor quality image frames could cause lower probability of recognition. The filtering technique introduced in this paper can improve input into machine vision algorithms. Another application for this technique is digital transmission to filter out unwanted images prior to transmission or to selectively enhance the poor quality frames. A major portion of current research into quality in digital image sequences focuses on transmission systems where an input high quality image sequence can be compared to the lower quality image sequence received at the output of the transmission system. However, this paper shows a technique for judging the quality of the input image frames prior to transmission, without a transmission system or without any knowledge of the higher quality image input. The impact of digital image artifacts on the spatio-temporal quality are shown. The quality variations in the individual frames of the input image sequence are charted to show which frames are of lower quality and thus need filtering. C1 USAF, Res Lab, AFRL, SNAT,Target Recognit Branch, Wright Patterson AFB, OH 45433 USA. RP Power, GJ (reprint author), USAF, Res Lab, AFRL, SNAT,Target Recognit Branch, 2010 5th St, Wright Patterson AFB, OH 45433 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2886-8 J9 P SOC PHOTO-OPT INS PY 1998 VL 3431 BP 72 EP 80 DI 10.1117/12.330188 PG 9 WC Engineering, Aerospace; Imaging Science & Photographic Technology SC Engineering; Imaging Science & Photographic Technology GA BM19T UT WOS:000078007900009 ER PT S AU Power, GJ Karim, MA AF Power, GJ Karim, MA BE Zelnio, EG TI Determining a confidence factor for automatic target recognition based on image sequence quality SO ALGORITHMS FOR SYNTHETIC APERTURE RADAR IMAGERY V SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Algorithm for Synthetic Aperture Radar Imagery V CY APR, 1998 CL ORLANDO, FL SP SPIE DE target recognition; image quality; probability of recognition; image sequence; image degradation AB For the Automatic Target Recognition (ATR) algorithm, the quality of the input image sequence can be a major determining factor as to the ATR algorithm's ability to recognize an object. Based on quality, an image can be easy to recognize, barely recognizable or even mangled beyond recognition. If a determination of the image quality can be made prior to entering the ATR algorithm, then a confidence factor can be applied to the probability of recognition. This confidence factor can be used to rate sensors; to improve quality through selectively preprocessing image sequences prior to applying ATR; or to limit the problem space by determining which image sequences need not be processed by the ATR algorithm. It could even determine when human intervention is needed. To get a flavor for the scope of the image quality problem, this paper reviews analog and digital forms of image degradation. It looks at traditional quality metric approaches such as peak signal-to-noise ratio (PSNR). It examines a newer metric based on human vision data, a metric introduced by the Institute for Telecommunication Sciences (ITS). These objective quality metrics can be used as confidence factors primarily in ATR systems that use image sequences degraded due to transmission systems. However, to determine the quality metric, a transmission system needs the original input image sequence and the degraded output image sequence. This paper suggests a more general approach to determining quality using analysis of spatial and temporal vectors where the original input sequence is not explicitly given. This novel approach would be useful where there is no transmission system but where the ATR system is part of the sensor, on-board a mobile platform. The results of this work are demonstrated on a few standard image sequences. C1 USAF, Res Lab, SNAT, Target Recognit Branch, Wright Patterson AFB, OH 45433 USA. RP Power, GJ (reprint author), USAF, Res Lab, SNAT, Target Recognit Branch, 2010 5th St, Wright Patterson AFB, OH 45433 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2819-1 J9 P SOC PHOTO-OPT INS PY 1998 VL 3370 BP 156 EP 165 DI 10.1117/12.321819 PG 10 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BL85L UT WOS:000076935900015 ER PT S AU Velten, VJ AF Velten, VJ BE Zelnio, EG TI Geometric invariance for synthetic aperture radar (SAR) sensors SO ALGORITHMS FOR SYNTHETIC APERTURE RADAR IMAGERY V SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Algorithm for Synthetic Aperture Radar Imagery V CY APR, 1998 CL ORLANDO, FL SP SPIE DE synthetic aperture radar; scattering centers; geometric invariance; model-based vision AB Synthetic Aperture Radar (SAR) sensors have many advantages over electro-optical sensors (EO) for target recognition applications, such as range-independent resolution and superior poor weather performance. However, the relative unavailability of SAR data to the basic research community has retarded analysis of the fundamental invariant properties of SAR sensors relative to the extensive invariant literature for EO, and in particular photographic sensors. This paper develops the basic geometric imaging transformation associated with SAR from first principles, and then gives an existence proof for several geometric scatter configurations which give rise to SAR image invariants. C1 USAF, Res Lab, SNAT, Wright Patterson AFB, OH 45433 USA. RP Velten, VJ (reprint author), USAF, Res Lab, SNAT, 2010 5th St, Wright Patterson AFB, OH 45433 USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2819-1 J9 P SOC PHOTO-OPT INS PY 1998 VL 3370 BP 176 EP 187 DI 10.1117/12.321821 PG 12 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BL85L UT WOS:000076935900017 ER PT S AU Bryant, M Worrell, S Dixon, A AF Bryant, M Worrell, S Dixon, A BE Zelnio, EG TI MSE template size analysis for MSTAR data SO ALGORITHMS FOR SYNTHETIC APERTURE RADAR IMAGERY V SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Algorithm for Synthetic Aperture Radar Imagery V CY APR, 1998 CL ORLANDO, FL SP SPIE AB Analysis of statistical pattern recognition algorithms is typically performed using stationary, gaussian noise to simplify the analysis. An example is the excellent paper titled, "Effects of Sample Size in Classifier Design", which was written by Keinosuke Fukunaga and Raymond Hayes and published in the August 1989 issue of IEEE Transactions on Pattern Analysis and Machine Intelligence. One of the main conclusions of this paper is that more training samples will improve the estimation of classifier design parameters and classifier performance. This conclusion is valid when the observed signatures are stationary. However, when the observed signatures are non-stationary, as is the case for the synthetic aperture radar (SAR) data collected for the Moving and Stationary Target Acquisition and Recognition (MSTAR) program, more samples can actually corrupt the design parameter estimation process and lead to degraded performance. This fact has been known for some time, which explains the standard practice of designing templates at various pose angles. However, no theory currently exists to determine the optimum number of signatures to use in the template design process. This paper presents some initial work to determine the optimum number of samples to use. C1 AFRL, SNAT, ATR Technol Branch, Wright Patterson AFB, OH 45433 USA. RP Bryant, M (reprint author), AFRL, SNAT, ATR Technol Branch, 2010 1st St, Wright Patterson AFB, OH 45433 USA. NR 0 TC 7 Z9 10 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2819-1 J9 P SOC PHOTO-OPT INS PY 1998 VL 3370 BP 396 EP 405 DI 10.1117/12.321844 PG 10 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BL85L UT WOS:000076935900037 ER PT S AU Deardorf, CE AF Deardorf, CE BE Zelnio, EG TI The HEATR project: ATR algorithm parallelization SO ALGORITHMS FOR SYNTHETIC APERTURE RADAR IMAGERY V SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Algorithm for Synthetic Aperture Radar Imagery V CY APR, 1998 CL ORLANDO, FL SP SPIE DE automatic target recognition (ATR); High Performance Computing (HPC); parallel processing; model-based vision; template-based ATR; model-based ATR; MSTAR; Common HPC Software Support Initiative (CHSSI); high performance computing modernization program (HPCMP) AB High Performance Computing (KPC) Embedded Application for Target Recognition (HEATR) is a project funded by the High Performance Computing Modernization Office (HPCMO) through the Common HPC Software Support Initiative (CHSSI). The goal of CHSSI is to produce portable, parallel, multi-purpose, freely distributable? support software to exploit emerging parallel computing technologies and enable application of scalable HPG's for various critical DoD applications. Specifically, the CHSSI goal for HEATR is to provide portable, parallel versions of several existing ATR detection and classification algorithms to the ATR-user community to achieve near real-time capability. The HEATR project will create parallel versions of existing automatic target recognition (ATR) detection and classification algorithms and generate reusable code that will support porting and software development process for ATR HPC software. The HEATR Team has selected detection/classification algorithms from both the model-based and training-based (template-based) arena in order to consider the parallelization requirements for detection/classification algorithms across ATR technology. This would allow the Team to assess the impact that parallelization would have on detection/classification performance across ATR technology. A field demo is included in this project. Finally, any parallel tools produced to support the project will be refined and returned to the ATR user community along with the parallel ATR algorithms. This paper will review 1. HPCMP structure as it relates to HEATR, 2. Overall structure of the HEATR project, 3. Preliminary results for the first algorithm Alpha Test, 4. CHSSI requirements for HEATR, 5. Project management issues and lessons learned. C1 USAF, Res Lab, SNAS, Wright Patterson AFB, OH 45433 USA. RP Deardorf, CE (reprint author), USAF, Res Lab, SNAS, Bldg 23,2010 5th St, Wright Patterson AFB, OH 45433 USA. NR 0 TC 0 Z9 0 U1 0 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2819-1 J9 P SOC PHOTO-OPT INS PY 1998 VL 3370 BP 420 EP 427 DI 10.1117/12.321846 PG 8 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BL85L UT WOS:000076935900039 ER PT S AU Pack, DJ Tamburino, LA Sturtz, K AF Pack, DJ Tamburino, LA Sturtz, K BE Zelnio, EG TI An optimal target recognition method using accumulated evidence SO ALGORITHMS FOR SYNTHETIC APERTURE RADAR IMAGERY V SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Algorithm for Synthetic Aperture Radar Imagery V CY APR, 1998 CL ORLANDO, FL SP SPIE DE object recognition; matching; optimization; pose estimation AB In this paper we present a new model-based feature matching method for an object recognition system. The actual matching takes place on a 2D image space by comparing a projected image of a 3D model with a sensor-extracted image of an actual target. The proposed method can be used with images generated by a wide variety of both camera and radar sensors, but we focus our attention on camera images with some discussions on synthetic aperture radar images. The effectiveness of the method is demonstrated only using point features. An extension. to include region features should require some but not major revisions to the main structure of the proposed method. The method contains three phases to complete the target recognition process. The inputs to the method are a model projected image, a sensor-extracted image, an estimated current pose of the sensor with respect to a reference coordinate frame, and the Jacobian function associated with the estimated current sensor pose which relates 3D target features with 2D image features. The first stage uses geometric information of the target model to limit the number of possible corresponding feature sets, the second stage generates a set of possible sensor pose changes by solving a set of optimization problems, and the final stage finds the "best" change of sensor pose out of all possible ones. This change of sensor pose is added to the current sensor pose to form a new sensor location and orientation. The revised pose can then be used to reproject the model features and subsequently compute a compatibility measure between the model-projected and sensor-extracted images: this quantifies the reliability of the desired target recognition[10]. In this paper we describe each of the three stages of the method and provide experimental results to demonstrate its validity. C1 USAF Acad, Dept Elect Engn, Colorado Springs, CO 80840 USA. RP Pack, DJ (reprint author), USAF Acad, Dept Elect Engn, Colorado Springs, CO 80840 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2819-1 J9 P SOC PHOTO-OPT INS PY 1998 VL 3370 BP 470 EP 480 DI 10.1117/12.321850 PG 11 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BL85L UT WOS:000076935900044 ER PT S AU Diemunsch, J Wissinger, J AF Diemunsch, J Wissinger, J BE Zelnio, EG TI Moving and stationary target acquisition and recognition (MSTAR) model-based automatic target recognition: Search technology for a robust ATR SO ALGORITHMS FOR SYNTHETIC APERTURE RADAR IMAGERY V SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Algorithm for Synthetic Aperture Radar Imagery V CY APR, 1998 CL ORLANDO, FL SP SPIE AB DARPA/Air Force Research Laboratory Moving and Stationary Target Acquisition and Recognition (MSTAR) program is developing state-of-the-art model based vision approach to Synthetic Aperture Radar (SAR) Automatic Target Recognition (ATR). The model-based approach requires using off-line developed target models in an on-line hypothesize-and-test manner to compare predicted target signatures with image data and output target reports. Central to this model-based ATR is the PEMS (Predict-Extract-Match-Search) subsystem. The Search module is critical to PEMS by providing intelligent control to traverse the hypothesis feature space. A major MSTAR goal is to demonstrate robust ATR for variations in targets including partially hidden targets. This paper will provide an update on the technology being developed under MSTAR and the status of this model based ATR research, specifically concentrating on the Search Module. C1 AFRL, SNAA, Wright Patterson AFB, OH 45433 USA. RP Diemunsch, J (reprint author), AFRL, SNAA, Wright Patterson AFB, OH 45433 USA. NR 0 TC 16 Z9 16 U1 0 U2 3 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2819-1 J9 P SOC PHOTO-OPT INS PY 1998 VL 3370 BP 481 EP 492 DI 10.1117/12.321851 PG 12 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BL85L UT WOS:000076935900045 ER PT S AU Ross, T Worrell, S Velten, V Mossing, J Bryant, M AF Ross, T Worrell, S Velten, V Mossing, J Bryant, M BE Zelnio, EG TI Standard SAR ATR evaluation experiments using the MSTAR public release data set SO ALGORITHMS FOR SYNTHETIC APERTURE RADAR IMAGERY V SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Algorithm for Synthetic Aperture Radar Imagery V CY APR, 1998 CL ORLANDO, FL SP SPIE DE ATR; automatic target recognition; evaluation; SAR; data sets; performance; standards AB The recent public release of high resolution Synthetic Aperture Radar (SAR) data collected by the DARPA/AFRL Moving and Stationary Target Acquisition and Recognition (MSTAR) program has provided a unique opportunity to promote and assess progress in SAR ATR algorithm development. This paper will suggest general principles to follow and report on a specific ATR performance experiment using these principles and this data. The principles and experiments are motivated by AFRL experience with the evaluation of the MSTAR ATR. C1 USAF, Res Lab, Sensors Directorate, Sensor ATR Technol Div, Wright Patterson AFB, OH 45433 USA. RP Ross, T (reprint author), USAF, Res Lab, Sensors Directorate, Sensor ATR Technol Div, AFRL SNA 2010 5th St, Wright Patterson AFB, OH 45433 USA. NR 0 TC 97 Z9 109 U1 0 U2 9 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2819-1 J9 P SOC PHOTO-OPT INS PY 1998 VL 3370 BP 566 EP 573 DI 10.1117/12.321859 PG 8 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BL85L UT WOS:000076935900052 ER PT S AU Williams, R Gross, D Palomino, A Westerkamp, J Wardell, D AF Williams, R Gross, D Palomino, A Westerkamp, J Wardell, D BE Zelnio, EG TI 1D HRR data analysis and ATR assessment SO ALGORITHMS FOR SYNTHETIC APERTURE RADAR IMAGERY V SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Algorithm for Synthetic Aperture Radar Imagery V CY APR, 1998 CL ORLANDO, FL SP SPIE DE HRR; ATR; match surface; Fisher surface; performance evaluation; target variants AB High range resolution (HRR) radar is important for its all-weather, day/night, long standoff capability. Additionally, it is an excellent sensor for identifying moving ground targets because it produces high resolution target signatures and because targets can be separated from ground clutter using Doppler processing. Ongoing research under the System Oriented HRR Automatic Recognition Program (SHARP) has led to an increased understanding of the HRR data, the target separability, and a baseline assessment of target recognition algorithms using template based approaches. C1 USAF, Res Lab, Wright Patterson AFB, OH 45433 USA. RP Williams, R (reprint author), USAF, Res Lab, 2241 Av Circle, Wright Patterson AFB, OH 45433 USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2819-1 J9 P SOC PHOTO-OPT INS PY 1998 VL 3370 BP 588 EP 599 DI 10.1117/12.321861 PG 12 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BL85L UT WOS:000076935900054 ER PT J AU Kulkarni, PM Tripathi, RC Michalek, JE AF Kulkarni, PM Tripathi, RC Michalek, JE TI Maximum (Max) and Mid-P confidence intervals and p values for the standardized mortality and incidence ratios SO AMERICAN JOURNAL OF EPIDEMIOLOGY LA English DT Article DE confidence intervals; Poisson distribution; risk; significance tests ID SHORTCUT METHOD AB The authors present algorithms to compute the confidence interval for a Poisson parameter (lambda) and the p value for testing the hypothesis that lambda is equal to a constant, which can be used to make inferences about the standardized mortality ratio and the standardized incidence ratio. The p value and confidence interval always agree, despite the discrete nature of the Poisson distribution. The authors also give simple equations to compute numeric approximations of the confidence limits that do not require the use of any probability distributions. An example based on data arising from a study of cancer incidence is given. C1 Univ S Alabama, Dept Math & Stat, Mobile, AL 36688 USA. Univ Texas, Dept Math & Stat, San Antonio, TX 78285 USA. Armstrong Lab, Brooks AFB, TX 78235 USA. RP Kulkarni, PM (reprint author), Univ S Alabama, Dept Math & Stat, Mobile, AL 36688 USA. NR 20 TC 10 Z9 10 U1 0 U2 0 PU JOHNS HOPKINS UNIV SCHOOL HYGIENE PUB HEALTH PI BALTIMORE PA 111 MARKET PLACE, STE 840, BALTIMORE, MD 21202-6709 USA SN 0002-9262 J9 AM J EPIDEMIOL JI Am. J. Epidemiol. PD JAN 1 PY 1998 VL 147 IS 1 BP 83 EP 86 PG 4 WC Public, Environmental & Occupational Health SC Public, Environmental & Occupational Health GA YQ848 UT WOS:000071429700012 PM 9440403 ER PT J AU Naef, RW Allbert, JR Ross, EL Weber, BM Martin, RW Morrison, JC AF Naef, RW Allbert, JR Ross, EL Weber, BM Martin, RW Morrison, JC TI Premature rupture of membranes at 34 to 37 weeks' gestation: Aggressive versus conservative management SO AMERICAN JOURNAL OF OBSTETRICS AND GYNECOLOGY LA English DT Article DE premature rupture of membranes; induction; chorioamnionitis ID EXPECTANT MANAGEMENT; BIRTH-WEIGHT; TERM; AGE AB OBJECTIVE: Our purpose was to compare induction of labor with preterm rupture of membranes between 34 and 37 weeks' gestation with expectant management. STUDY DESIGN: In this prospective investigation 120 gravid women at greater than or equal to 34 weeks 0 days and <36 weeks 6 days of gestation were randomized to receive oxytocin induction (n = 57) or observation (n = 63). RESULTS: Estimated gestational age at rupture of membranes (34.3 +/- 1.4 weeks vs 34.5 +/- 1.4 weeks) and ultrasonographically estimated fetal weight (2230 +/- 321 gm vs 2297 +/- 365 gm) were equivalent between groups (not significant). Chorioamnionitis occurred more often (16% vs 2%, p = 0.007), and maternal hospital stay (5.2 +/- 6.8 days vs 2.6 +/- 1.6 days, p = 0.006) was significantly longer in the control group. Neonatal sepsis was also more common in the observation group (n = 3) than among induction patients (n = 0), but the difference was not statistically significant. CONCLUSION: Aggressive management of preterm premature rupture of the membranes at greater than or equal to 34 weeks 0 days of gestation by induction of labor is safe for the infant in our population and avoids maternal-neonatal infectious complications. C1 Univ Mississippi, Med Ctr, Dept Obstet & Gynecol, Jackson, MS 39216 USA. Carolinas Med Ctr, Jackson, MS USA. USAF, Keesler Med Ctr, Jackson, MS USA. RP Naef, RW (reprint author), Vicksburg Hosp Med Fdn, Vicksburg, MS 39180 USA. NR 14 TC 83 Z9 84 U1 0 U2 2 PU MOSBY-YEAR BOOK INC PI ST LOUIS PA 11830 WESTLINE INDUSTRIAL DR, ST LOUIS, MO 63146-3318 USA SN 0002-9378 J9 AM J OBSTET GYNECOL JI Am. J. Obstet. Gynecol. PD JAN PY 1998 VL 178 IS 1 BP 126 EP 130 DI 10.1016/S0002-9378(98)70638-6 PN 1 PG 5 WC Obstetrics & Gynecology SC Obstetrics & Gynecology GA YU977 UT WOS:000071776100022 PM 9465815 ER PT J AU Cantu, E Ryan, WJ Tansey, S Johnson, CS AF Cantu, E Ryan, WJ Tansey, S Johnson, CS TI Tracheoesophageal speech: Predictors of success and social validity ratings SO AMERICAN JOURNAL OF OTOLARYNGOLOGY LA English DT Article ID TOTAL LARYNGECTOMY; VOICE REHABILITATION; PUNCTURE; RESTORATION; COMPLICATIONS AB Purpose: The purpose of this study was to examine long-term success rates and predictors of success for patients who had undergone either primary or secondary tracheoesophageal puncture. An additional aim was to compare judgments of communication effectiveness made by a speech-language pathologist with those made by the patient or significant other. Patients and Methods: Thirty-six laryngectomees were initially rated on a 5-point functional communication scale. These ratings resulted in the formation of two distinct groups that were identified as "successful" and "unsuccessful." The groups were compared on the basis of age at time of surgery and 10 categorical variables that have been implicated in the success or failure of tracheoesophageal puncture surgery. Results: Results indicated that nearly two thirds of the patients had successful communication at an average of approximately 4 years posttracheoesophageal puncture. For the 13 patients judged as "unsuccessful," reduced vision, limited arm/hand movement, and history of radiotherapy were found in significantly greater numbers. When communication profile ratings made by a speech-language pathologist were compared with those made by the patient or significant other (P/SO), approximately one-third varied by at least "1" scale value, with the vast majority resulting in comparatively higher ratings by the speech-language pathologist. Conclusion: The findings of this study are in general agreement with previously published success rates for tracheoesophageal puncture and attest to the long-term nature of these success rates in a majority of patients. Additional investigation is necessary to identify factors that may contribute to discrepancies between clinician expectations and those of the patient or significant other. Copyright (C) 1998 by W.B. Saunders Company. C1 Wilford Hall USAF Med Ctr, Dept Audiol Speech Pathol, Lackland AFB, TX 78236 USA. RP Cantu, E (reprint author), 59 Med Wing AETC-PSSOS,2200 Bergquist Dr,Ste 1, Lackland AFB, TX 78236 USA. NR 18 TC 18 Z9 19 U1 0 U2 0 PU W B SAUNDERS CO PI PHILADELPHIA PA INDEPENDENCE SQUARE WEST CURTIS CENTER, STE 300, PHILADELPHIA, PA 19106-3399 USA SN 0196-0709 J9 AM J OTOLARYNG JI Am. J. Otolaryngol. PD JAN-FEB PY 1998 VL 19 IS 1 BP 12 EP 17 DI 10.1016/S0196-0709(98)90059-X PG 6 WC Otorhinolaryngology SC Otorhinolaryngology GA YR522 UT WOS:000071503700003 PM 9470945 ER PT J AU Arriaga, MA Dixon, P AF Arriaga, MA Dixon, P TI Cytotoxicity of cytokeratin monoclonal antibody against keratinocytes: A possible therapeutic adjunct for cholesteatoma? SO AMERICAN JOURNAL OF OTOLOGY LA English DT Article; Proceedings Paper CT National Meeting of the American-Otological-Society CY MAY 10-11, 1997 CL SCOTTSDALE, ARIZONA SP Amer Otol Soc DE cholesteatoma; monoclonal antibodies; biological therapy ID ACQUIRED CHOLESTEATOMA; PATTERNS; EXPRESSION; EPITHELIUM; CELLS AB Hypothesis: Monoclonal antibodies directed against cytokeratin subtypes in cholesteatoma produce growth inhibition of keratinocytes. Background: Despite elegant surgical procedures for cholesteatoma, residual disease is an important clinical problem. Although gross cholesteatoma removal usually is feasible, microscopic foci of residual keratinocytes may develop into clinically significant disease. This study was designed to evaluate the keratinocyte cytotoxicity of monoclonal antibodies directed against a cytokeratin subtype relatively unique to cholesteatoma. Methods: Keratinocytes and skin fibroblasts were trypsinized, counted, and seeded in multiwell plates. The cells were exposed to mouse monoclonal antibody to cytokeratin 10 at dilutions of 1:10, 1:25, 1:50, 1:100, and 1:200 with six replicates. After 24-, 48-, and 96-hour incubations, cells that had been pulsed with 3H-thymidine were harvested. Cellular DNA was processed for quantification of SH-thymidine incorporation with a beta scintillation counter. Cells exposed to antibody are reported as percent inhibition relative to controls. Results: inhibition ranged from 88.9% for the 1:10 concentration to 26.9% for the 1:200 concentration after 24 hours of incubation. Similar effects were noted at the 48- and 96-hour intervals. Overall, the effect was significantly more pronounced on the keratinocytes than inhibition on skin fibroblasts. Conclusions: These results suggest that monoclonal antibodies have in vitro activity against keratinocytes. Additional investigation of a possible role for cytokeratin monoclonal antibodies should be pursued with a goal of developing a clinically useful biologic adjunct for cholesteatoma management. C1 Allegheny Gen Hosp, Hearing & Balance Ctr, Pittsburg Ear Associates, Pittsburgh, PA 15212 USA. Wilford Hall USAF Med Ctr, Lackland AFB, TX 78236 USA. RP Arriaga, MA (reprint author), Allegheny Gen Hosp, Hearing & Balance Ctr, Pittsburg Ear Associates, 320 E North Ave, Pittsburgh, PA 15212 USA. NR 9 TC 28 Z9 28 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 USA SN 0192-9763 J9 AM J OTOL JI Am. J. Otol. PD JAN PY 1998 VL 19 IS 1 BP 26 EP 29 PG 4 WC Otorhinolaryngology SC Otorhinolaryngology GA ZD086 UT WOS:000072650000005 PM 9455943 ER PT J AU Wolfe, RR Norwick, ML Bofill, JA AF Wolfe, RR Norwick, ML Bofill, JA TI Fatal maternal beta-hemolytic group B streptococcal meningitis: A case report SO AMERICAN JOURNAL OF PERINATOLOGY LA English DT Article DE beta-hemolytic group B streptococcus; maternal meningitis; maternal mortality AB Meningitis secondary to beta-hemolytic group B streptococcus is rare and represents less than 1% of cases of adult meningitis. We report the first known case of maternal mortality attributed to beta-hemolytic group B streptococcal meningitis. A 23-year-old African-American woman with a benign prenatal course delivered a viable male infant at term. Labor was complicated by thick meconium for which a saline amnioinfusion was utilized. On postpartum Day 1, the patient complained of right hip pain and a headache. Within 12 hr the patient was comatose with fixed and dilated pupils. Life support measures were discontinued secondary to absence of electrocortical activity. Postmortem examination revealed endomyometritis and fulminant meningitis with gram-positive cocci. Placental histologic sections demonstrated acute chorioamnionitis and bateriological cultures noted beta-hemolytic group B streptococcus. The virulence of beta-hemolytic group B streptococcus in the neonate is well recognized. This case demonstrates that beta-hemolytic group B streptococcus is also a potentially fatal maternal pathogen. C1 USAF, Med Ctr, Dept Obstet & Gynecol, Wright Patterson AFB, OH USA. Wright State Univ, Sch Med, Dept Obstet & Gynecol, Dayton, OH USA. RP Bofill, JA (reprint author), E Carolina Univ, Sch Med, Dept Obstet & Gynecol, 4S-22 Brody, Greenville, NC 27858 USA. NR 3 TC 9 Z9 9 U1 0 U2 0 PU THIEME MEDICAL PUBL INC PI NEW YORK PA 333 SEVENTH AVE, NEW YORK, NY 10001 USA SN 0735-1631 J9 AM J PERINAT JI Am. J. Perinatol. PY 1998 VL 15 IS 11 BP 597 EP 600 DI 10.1055/s-2007-994076 PG 4 WC Obstetrics & Gynecology; Pediatrics SC Obstetrics & Gynecology; Pediatrics GA 169BY UT WOS:000078728700001 PM 10064199 ER PT J AU Laskin, WB Fetsch, JF Mostofi, FK AF Laskin, WB Fetsch, JF Mostofi, FK TI Angiomyofibroblastomalike tumor of the male genital tract - Analysis of 11 cases with comparison to female angiomyofibroblastoma and spindle cell lipoma SO AMERICAN JOURNAL OF SURGICAL PATHOLOGY LA English DT Article; Proceedings Paper CT 85th Annual Meeting of the United-States-and-Canadian-Academy-of-Pathology CY MAR 23-29, 1996 CL WASHINGTON, D.C. SP US & Canadian Acad Pathol DE angiomyofibroblastoma; spindle cell lipoma; myofibroblast; male genital region; vulvovaginal region; soft tissue ID SOLITARY FIBROUS TUMOR; LEIOMYOMATOSIS PERITONEALIS DISSEMINATA; SOFT-TISSUE TUMOR; AGGRESSIVE ANGIOMYXOMA; PLEOMORPHIC LIPOMA; GLOMUS TUMORS; VULVA; CD34; HEMANGIOPERICYTOMAS; VARIANT AB The clinicopathologic features and immunoprofile of 11 cases of an uncharacterized male genital tract tumor with features of vulvovaginal angiomyofibroblastoma (AMF) and spindle cell lipoma (male AMF-like tumor) are described. The lesions presented as a mass involving the scrotum (six cases) or inguinal region (five cases) in males ranging in age from 39 to 88 years (median 57). The tumors were superficially located and well-marginated and ranged in size from 2.5 to 14 cm (approximate mean 7 cm). Microscopically, they were composed of tapered spindled cells proliferating between numerous small to medium-sized vessels. Epithelioid appearing stromal cells were a focal finding in four cases. Mitotic activity was minimal with no abnormal mitotic figures identified. Mild nuclear atypia was identified in two cases. The tumors possessed an acid mucopolysaccharide-rich, finely collagenous stroma. A small quantity of intralesional fat was present in six cases. Tumor cells exhibited immunoreactivity for vimentin (seven of seven cases), progesterone receptor protein (five of seven cases), CD34 (four of eight cases), estrogen receptor protein (three of seven cases), desmin (three of eight cases), muscle-specific actin (three of eight cases), and smooth-muscle actin (two of eight cases) but not for S-100 protein, One of seven patients with follow-up after simple excision had recurrent/persistent disease. The male AMF-like tumor is a soft-tissue neoplasm of the male genital tract that shares clinicopathologic features and a proposed perivascular stem cell derivation with both the female angiomyofibroblastoma and spindle cell lipoma. C1 Northwestern Univ, Sch Med, Dept Pathol, Chicago, IL 60611 USA. USAF, Inst Pathol, Dept Soft Tissue Pathol, Washington, DC 20330 USA. USAF, Inst Pathol, Dept Genitourinary Pathol, Washington, DC 20330 USA. RP Laskin, WB (reprint author), Northwestern Univ, Sch Med, Dept Pathol, 303 E Super St,345 Passavant Pavil, Chicago, IL 60611 USA. NR 53 TC 67 Z9 80 U1 0 U2 2 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 USA SN 0147-5185 J9 AM J SURG PATHOL JI Am. J. Surg. Pathol. PD JAN PY 1998 VL 22 IS 1 BP 6 EP 16 DI 10.1097/00000478-199801000-00002 PG 11 WC Pathology; Surgery SC Pathology; Surgery GA YN584 UT WOS:000071184000002 PM 9422311 ER PT J AU Lavine, BK Moores, AJ Mayfield, HT Faruque, A AF Lavine, BK Moores, AJ Mayfield, HT Faruque, A TI Fuel spill identification by gas chromatography genetic algorithms/pattern recognition techniques SO ANALYTICAL LETTERS LA English DT Article DE discriminant analysis; feature selection; fuel-spill identification; genetic algorithms; pattern recognition ID PATTERN-RECOGNITION AB Gas chromatography and pattern recognition methods were used to develop a potential method for typing jet fuels so a spill sample in the environment can be traced to its source. The test data consisted of 256 gas chromatograms of neat jet fuels. 31 fuels that have undergone weathering in a subsurface environment were correctly identified by type using discriminants developed from the gas chromatograms of the neat jet fuels. Coalescing poorly resolved peaks, which occurred during preprocessing, diminished the resolution and hence information content of the GC profiles. Nevertheless, a genetic algorithm was able to extract enough information from these profiles to correctly classify the chromatograms of weathered fuels. This suggests that cheaper and simpler GC instruments can be used to type jet fuels. C1 Clarkson Univ, Dept Chem, Potsdam, NY 13676 USA. Mississippi Valley State Univ, Dept Comp Sci, Itta Bena, MS 38941 USA. AFCESA, RDVC, Tyndall AFB, FL 32403 USA. RP Lavine, BK (reprint author), Clarkson Univ, Dept Chem, Box 5810, Potsdam, NY 13676 USA. NR 23 TC 12 Z9 12 U1 1 U2 2 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 0003-2719 J9 ANAL LETT JI Anal. Lett. PY 1998 VL 31 IS 15 BP 2805 EP 2822 PG 18 WC Chemistry, Analytical SC Chemistry GA 142CE UT WOS:000077181700017 ER PT J AU Haws, JL Herman, N Clark, Y Bjoraker, R Jones, D AF Haws, JL Herman, N Clark, Y Bjoraker, R Jones, D TI The chemical stability and sterility of sodium thiopental after preparation SO ANESTHESIA AND ANALGESIA LA English DT Article; Proceedings Paper CT Post Graduate Assembly of the New-York-State-Society-of-Anesthesiologists Annual Meeting CY DEC, 1995 CL NEW YORK, NEW YORK SP New York State Soc Anesthesiologists ID PERFORMANCE LIQUID-CHROMATOGRAPHY; COMPATIBILITY; GROWTH AB Manufacturer's instructions recommend discarding unused portions of sodium thiopental 24 h after reconstitution. Heeding this recommendation may result in the disposal of a large proportion of prepared thiopental. Although thiopental is relatively inexpensive, the volume prepared by many anesthesia departments could make this waste significant. To address this possibility, we investigated the chemical stability and sterility of thiopental in pharmacy-prepared, prefilled syringes. Stock solutions of thiopental were mixed and drawn into syringes under sterile conditions by pharmacists or pharmacy assistants. Fifty-six samples were stored under refrigeration (3 degrees C); the remaining 56 samples were stored at room temperature (22 degrees C). Each day for 7 days, eight samples from each group were analyzed by using high-performance liquid chromatography for chemical stability and cultured for microbiological colonization. Differences in thiopental concentration between the room temperature and the refrigerated samples were measured over time by using repeated-measures analysis of variance (P less than or equal to 0.05). Three positive culture samples (S. epidermidis and S. hemolyticus) most likely represent laboratory contamination and not colonization. At 22 degrees C, thiopental remains stable and sterile for 6 days and well beyond 7 days at 3 degrees C. Implications: This study examines the shelf life of the anesthetic drug thiopental in pharmacy-filled syringes stored at either room temperature or under refrigeration. The results justify the use of prepared solutions beyond the package insert recommendation of 24 h. C1 Witford Hall Med Ctr, Dept Anesthesiol, Lackland AFB, TX 78236 USA. Witford Hall Med Ctr, Dept Pharm, Lackland AFB, TX 78236 USA. Univ Texas, Hlth Sci Ctr, Dept Anesthesiol, Anesthesia Res Labs, San Antonio, TX 78284 USA. Cornell Univ, Med Ctr, New York Hosp, Dept Anesthesiol, New York, NY 10021 USA. RP Haws, JL (reprint author), 77th Med Grp, Dept Anesthesiol SGOSAH, 10535 Hosp Dr, Mather AFB, CA 95635 USA. NR 20 TC 19 Z9 19 U1 0 U2 2 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 USA SN 0003-2999 J9 ANESTH ANALG JI Anesth. Analg. PD JAN PY 1998 VL 86 IS 1 BP 208 EP 213 DI 10.1097/00000539-199801000-00040 PG 6 WC Anesthesiology SC Anesthesiology GA YN320 UT WOS:000071155100040 PM 9428880 ER PT J AU Murad, E AF Murad, E TI The shuttle glow phenomenon SO ANNUAL REVIEW OF PHYSICAL CHEMISTRY LA English DT Review DE shuttle glow; spacecraft glow; space chemistry; surface recombination; hyperthermal gas-surface collisions ID SPACECRAFT-ENVIRONMENT INTERACTION; TIME-DEPENDENT CHEMILUMINESCENCE; SURFACE-CATALYZED RECOMBINATION; VEHICLE GLOW; ATMOSPHERE EXPLORER; NITROGEN-DIOXIDE; OPTICAL GLOW; RADIATIVE RELAXATION; CHEMISTRY MODEL; SATELLITE AB Spacecraft in low earth orbit exhibit an unusual phenomenon: Surfaces facing the atmospheric wind produce a bright orange glow. This phenomenon was first noticed on the space shuttle but has since been verified as occurring on all spacecraft. The intensity of the glow depends on atmospheric density, on the angle between the velocity vector and the spacecraft surface, and on the temperature of the surface. This review summarizes the observations as well as the current explanation for the glow, namely its being due to NO2* formed in surface-aided recombination between O and NO. Laboratory measurements and surface studies related to the phenomenon are briefly discussed. C1 USAF, Res Lab, VSBM, Hanscom AFB, MA 01731 USA. RP Murad, E (reprint author), USAF, Res Lab, VSBM, Hanscom AFB, MA 01731 USA. EM murad@plh.af.mil NR 111 TC 23 Z9 23 U1 0 U2 5 PU ANNUAL REVIEWS INC PI PALO ALTO PA 4139 EL CAMINO WAY, PO BOX 10139, PALO ALTO, CA 94303-0139 USA SN 0066-426X J9 ANNU REV PHYS CHEM JI Annu. Rev. Phys. Chem. PY 1998 VL 49 BP 73 EP + DI 10.1146/annurev.physchem.49.1.73 PG 27 WC Chemistry, Physical SC Chemistry GA 130VP UT WOS:000076541300004 PM 15012425 ER PT S AU Myers, LR Keller, JG Rogers, SK Kabrisky, M AF Myers, LR Keller, JG Rogers, SK Kabrisky, M BE Rogers, SK Fogel, DB Bezdek, JC Bosacchi, B TI Evolution programs for Bayesian training of neural networks SO APPLICATIONS AND SCIENCE OF COMPUTATIONAL INTELLIGENCE SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE International Conference on Applications and Science of Computational Intelligence CY APR 13-16, 1998 CL ORLANDO, FL SP SPIE, Int Soc Opt Engn DE genetic algorithms; evolution programs; Bayesian learning; neural networks AB In this paper, it is shown that Evolution Programs can be used to search the weight space for Bayesian training of a Neural Network. Bayesian Analysis is an integration problem (as opposed to an optimization problem) over weight space. The first application of the Bayesian method primarily focused on using a Gaussian approximation of the posterior distribution in an area of high probability in the weight space instead of using formal integration. More recently, training a neural network in a Bayesian fashion has been accomplished by searching weight space for areas of high probability density which obviates the need for the Gaussian assumption. In particular, a hybrid Monte-Carlo method was used to search weight space in a logical manner to obtain an arbitrarily close approximation of the integration involved in a Bayesian analysis. Genetic Algorithms have been used in the past to determine the weights in an ANN, and (with some slight modifications) are ideally suited for searching the weight space to approximate the Bayesian integration. In this respect, the Bayesian framework provides a simple and elegant way to apply Evolution Programs to the ANN training problem. While this paper concentrates on using ANNs as classifiers, the generalization to regression problems is straightforward. C1 USAF, Inst Technol, Wright Patterson AFB, OH 45433 USA. RP Myers, LR (reprint author), USAF, Inst Technol, 2950 P St, Wright Patterson AFB, OH 45433 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2839-6 J9 P SOC PHOTO-OPT INS PY 1998 VL 3390 BP 90 EP 98 PG 9 WC Computer Science, Artificial Intelligence; Computer Science, Interdisciplinary Applications; Optics SC Computer Science; Optics GA BK80N UT WOS:000073452600009 ER PT S AU Wilson, T Rogers, S Oxley, M Rathbun, T DeSimio, M Kabrisky, M AF Wilson, T Rogers, S Oxley, M Rathbun, T DeSimio, M Kabrisky, M BE Rogers, SK Fogel, DB Bezdek, JC Bosacchi, B TI RBF iterative construction algorithm (RICA) SO APPLICATIONS AND SCIENCE OF COMPUTATIONAL INTELLIGENCE SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE International Conference on Applications and Science of Computational Intelligence CY APR 13-16, 1998 CL ORLANDO, FL SP SPIE, Int Soc Opt Engn DE Radial Basis Function; construction; adaptive AB A Radial Basis Function (RBF) Iterative Construction Algorithm (RICA) is presented that autonomously determines the size of the network architecture needed to perform classification on a given data set. The algorithm uses a combination of a Gaussian goodness-of-fit measure and Mahalanobis distance clustering to calculate the number of hidden nodes needed and to estimate the parameters of the hidden node basis functions. An iterative minimum squared error reduction method is used to optimize the output layer weights. RICA is compared to several neural network algorithms, including a fixed architecture multilayer perceptron (MLP), a fixed architecture RBF, and an adaptive architecture MLP, using optical character recognition and infrared image data. C1 USAF, Inst Technol, WPAFB, Wright Patterson AFB, OH 45433 USA. RP Wilson, T (reprint author), USAF, Inst Technol, WPAFB, 2950 P St, Wright Patterson AFB, OH 45433 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2839-6 J9 P SOC PHOTO-OPT INS PY 1998 VL 3390 BP 412 EP 419 DI 10.1117/12.304831 PG 8 WC Computer Science, Artificial Intelligence; Computer Science, Interdisciplinary Applications; Optics SC Computer Science; Optics GA BK80N UT WOS:000073452600043 ER PT S AU Blasch, E Gainey, J AF Blasch, E Gainey, J BE Rogers, SK Fogel, DB Bezdek, JC Bosacchi, B TI Physio-associative temporal sensor integration SO APPLICATIONS AND SCIENCE OF COMPUTATIONAL INTELLIGENCE SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE International Conference on Applications and Science of Computational Intelligence CY APR 13-16, 1998 CL ORLANDO, FL SP SPIE, Int Soc Opt Engn DE thalamic gating; association-cortex filter; association learning; sensor integration; tracking AB The paper describes the physio-associative temporal sensor integration algorithm which is motivated by the observed function of the thalamus and utilizes signals theory mathematics to model how a human efficiently perceives information in the environment. The algorithm is consistent with that of an aircraft pilot; namely, to estimate, filter, and predict sensed afferent signals and produce efferent controls under dynamic flight conditions. Dynamic sensor integration under uncertainty requires feature selection which can be formulated as a associative-learning problem in which sensed states are represented as current situational beliefs, and the information either excites or inhibits long-term memory associations. The objective of the learner/observer is to 1) abstract salient signals from the environment, 2) integrate the signal for real-time beliefs, and 3) compare beliefs to learned associations. Biologically, the paper models these processes from the biological systems of the eye, thalamus, and association-cortex; respectively. By selecting the optimal set of mutually non-exclusive sensors and comparing the integrated signal to learned associations, the physio-associative temporal algorithm maximizes the identification of targets in a simulated dynamic flight situation. C1 USAF, Inst Technol, Sensors Directorate, Avion Ctr,WPAFB, Wright Patterson AFB, OH 45433 USA. RP Blasch, E (reprint author), USAF, Inst Technol, Sensors Directorate, Avion Ctr,WPAFB, Wright Patterson AFB, OH 45433 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2839-6 J9 P SOC PHOTO-OPT INS PY 1998 VL 3390 BP 440 EP 450 DI 10.1117/12.304834 PG 11 WC Computer Science, Artificial Intelligence; Computer Science, Interdisciplinary Applications; Optics SC Computer Science; Optics GA BK80N UT WOS:000073452600046 ER PT S AU Foltz, TM Welsh, BM AF Foltz, TM Welsh, BM BE Tescher, AG TI Diagonal forms of symmetric convolution matrices for asymmetric multidimensional sequences SO APPLICATIONS OF DIGITAL IMAGE PROCESSING XXI SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Applications of Digital Image Processing XXI CY JUL 21-24, 1998 CL SAN DIEGO, CA SP SPIE DE symmetric convolution; discrete trigonometric transforms; discrete cosine transform; multidimensional filtering AB This paper presents diagonal forms of matrices representing symmetric convolution which is the underlying form of convolution for discrete trigonometric transforms. Symmetric convolution is identically equivalent to linear convolution for appropriately zero-padded sequences. These diagonal forms provide an alternate derivation of the symmetric convolution-multiplication property of the discrete trigonometric transforms. Derived in this manner, the symmetric convolution-multiplication property extends easily to multiple dimensions, and generalizes to multidimensional asymmetric sequences. The symmetric convolution of multidimensional asymmetric sequences can then be accomplished by taking the product of the trigonometric transforms of the sequences and then applying an inverse transform to the result. An example is given of how this theory can be used for applying a two-dimensional FDR filter with nonlinear phase which models atmospheric turbulence. C1 USAF, Inst Technol, Dept Elect & Comp Engn, Wright Patterson AFB, OH 45433 USA. RP Foltz, TM (reprint author), USAF, Inst Technol, Dept Elect & Comp Engn, 2950 P St Bldg 640, Wright Patterson AFB, OH 45433 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2915-5 J9 P SOC PHOTO-OPT INS PY 1998 VL 3460 BP 214 EP 225 DI 10.1117/12.323174 PG 4 WC Computer Science, Software Engineering SC Computer Science GA BL85W UT WOS:000076961900022 ER PT S AU Power, GJ Karim, MA Ahmed, F AF Power, GJ Karim, MA Ahmed, F BE Tescher, AG TI Charting image artifacts in digital image sequences using Velocital Information Content SO APPLICATIONS OF DIGITAL IMAGE PROCESSING XXI SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Applications of Digital Image Processing XXI CY JUL 21-24, 1998 CL SAN DIEGO, CA SP SPIE DE image quality; spatial-temporal analysis; digital transmission; image sequence; quality metric; velocital AB This paper introduces a metric called Velocital Information Content (VIC) which is used to chart quality variations in digital image sequences. Both spatially-based and temporally-based artifacts are charted using this single metric. VIC is based on the velocital information in each image. A mathematical formulation for VIC is shown along with its relation to the spatial and temporal information content. Some strengths and weaknesses of the VIC formulation are discussed. VIC is tested on some standard image sequences with various spatio-temporal attributes. VIC is also tested on a standard image sequence with various degrees of blurring using a linear blurring algorithm. Additionally, VIC is tested using standard sequences that have been processed through a digital transmission algorithm. The transmission algorithm is based on the discrete cosine transform (DCT), and thus introduces many of the known digital artifacts such as blocking. Finally, the ability of VIC to chart image artifacts is compared to a few other traditional quality metrics. VIC offers a different role from traditional transmission-based quality metrics which require two images: the original input image and degraded output image to calculate the quality metric. VIC can detect artifacts from a single image sequence by charting variations from the norm. Therefore, VIC offers a metric for judging the quality of the image frames prior to transmission, without a transmission system or without any knowledge of the higher quality image input. The differences between VIC and transmission-oriented quality metrics, can provide a different role for VIC in analysis and image sequence processing. C1 USAF, Res Lab, AFRL, SNAT,Target Recognit Branch, Wright Patterson AFB, OH 45433 USA. RP Power, GJ (reprint author), USAF, Res Lab, AFRL, SNAT,Target Recognit Branch, 2010 5th St, Wright Patterson AFB, OH 45433 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2915-5 J9 P SOC PHOTO-OPT INS PY 1998 VL 3460 BP 642 EP 651 DI 10.1117/12.323220 PG 4 WC Computer Science, Software Engineering SC Computer Science GA BL85W UT WOS:000076961900062 ER PT S AU Rockwell, BA Payne, DJ Hopkins, RA Hammer, DX Kennedy, PK Amnotte, RE Eilert, B Druessel, JJ Toth, CA Roach, WP Phillips, SL Stolarski, DJ Noojin, GD Thomas, RJ Cain, CP AF Rockwell, BA Payne, DJ Hopkins, RA Hammer, DX Kennedy, PK Amnotte, RE Eilert, B Druessel, JJ Toth, CA Roach, WP Phillips, SL Stolarski, DJ Noojin, GD Thomas, RJ Cain, CP BE Neev, J TI Retinal damage mechanisms from ultrashort laser exposure SO APPLICATIONS OF ULTRASHORT-PULSE LASERS IN MEDICINE AND BIOLOGY SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Applications of Ultrashort-Pulse Lasers in Medicine and Biology CY JAN 29-30, 1998 CL SAN JOSE, CA SP USAF Off Sci Res, Int Biomed Opt Soc, Soc Photo Opt Instrumentat Engineers DE eye; safety; laser; nonlinear optics; retinal damage AB Extensive research of ultrashort ocular damage mechanisms has shown that less energy is required for retinal damage for pulses shorter than one nanosecond. Laser minimum visible lesion (MVL) thresholds for retinal damage from ultrashort (i.e. < 1 ns) laser pulses occur at lower energies than in the nanosecond (ras) to microsecond (mu s) laser pulse regime. We review the progress made in determining the trends in retinal damage from laser pulses of one nanosecond to one hundred femtoseconds in the visible and near-infrared wavelength regimes. We discuss the most likely damage mechanism(s) operative in this pulse width regime and discuss implications on laser safety standards. C1 USAF, Res Lab, Human Effectiveness Directorate, Directed Energy Bioeffects Div,Opt Radiat Branch, Brooks AFB, TX 78235 USA. RP Rockwell, BA (reprint author), USAF, Res Lab, Human Effectiveness Directorate, Directed Energy Bioeffects Div,Opt Radiat Branch, 8111 18 St, Brooks AFB, TX 78235 USA. RI toth, cynthia/F-5614-2011 NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2694-6 J9 P SOC PHOTO-OPT INS PY 1998 VL 3255 BP 50 EP 55 DI 10.1117/12.308221 PG 6 WC Engineering, Biomedical; Optics SC Engineering; Optics GA BL09E UT WOS:000074239000006 ER PT J AU Vorbeck, C Lenke, H Fischer, P Spain, JC Knackmuss, HJ AF Vorbeck, C Lenke, H Fischer, P Spain, JC Knackmuss, HJ TI Initial reductive reactions in aerobic microbial metabolism of 2,4,6-trinitrotoluene SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Article ID PHANEROCHAETE-CHRYSOSPORIUM; PSEUDOMONAS SP; NITROAROMATIC COMPOUNDS; DEGRADATION; BIODEGRADATION; IDENTIFICATION; 2,4-DINITROTOLUENE; PRODUCTS; STRAIN; TRANSFORMATION AB Because of its high electron deficiency initial microbial transformations of 2,4,6-trinitrotoluene (TNT) are characterized by reductive rather than oxidation reactions. The reduction of the nitro groups seems to he the dominating mechanism, whereas hydrogenation of the aromatic ring, as described for picric acid, appears to be of minor importance, Thus, two bacterial strains enriched with TNT as a sole source of nitrogen under aerobic conditions, a gram-negative strain called TNT-8 and a gram-positive strain called TNT-32, carried our nitro-group reduction, In contrast, both a picric acid-utilizing Rhodococcus erythropolis strain, HL PM-I, and a 4-nitrotoluene-utilizing Mycobacterium sp. strain, HL 4-NT-1, possessed reductive enzyme systems, which catalyze ring hydrogenation, i.e., the addition of a hydride ion to the aromatic ring of TNT. The hydride-Meisenheimer complex thus formed (H(-)-TNT) was further converted to a yellow metabolite, which by electrospray mass and nuclear magnetic resonance spectral analyses was established as the protonated dihydride-Meisenheimer complex of TNT (2H(-)-TNT). Formation of hydride complexes could not be identified with the TNT-enriched strains TNT-8 and TNT-32, or with Pseudomonas sp. clone A (2NT(-)), for which such a mechanism has been proposed, Correspondingly, reductive denitration ofm TNT did not occur. C1 Univ Stuttgart, Fraunhofer Inst Grenzflachen & Bioverfahrenstech, D-70569 Stuttgart, Germany. Univ Stuttgart, Inst Mikrobiol, D-70569 Stuttgart, Germany. Univ Stuttgart, Inst Organ Chem, D-70569 Stuttgart, Germany. Armstrong Lab, EQC, Tyndall AFB, FL 32403 USA. RP Knackmuss, HJ (reprint author), Univ Stuttgart, Fraunhofer Inst Grenzflachen & Bioverfahrenstech, Nobelstr 12, D-70569 Stuttgart, Germany. EM hjkimb@uni-stuttgart.de NR 40 TC 106 Z9 112 U1 3 U2 15 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1752 N ST NW, WASHINGTON, DC 20036-2904 USA SN 0099-2240 J9 APPL ENVIRON MICROB JI Appl. Environ. Microbiol. PD JAN PY 1998 VL 64 IS 1 BP 246 EP 252 PG 7 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA YP406 UT WOS:000071273600039 PM 16349484 ER PT B AU Shang, JS Shang, CC AF Shang, JS Shang, CC BE ElDabaghi, F Morgan, K Parrott, K Periaux, J TI Simulating electromagnetic phenomena on an Intel Paragon XP/S system SO APPROXIMATIONS AND NUMERICAL METHODS FOR THE SOLUTION OF MAXWELL'S EQUATIONS SE INSTITUTE OF MATHEMATICS AND ITS APPLICATIONS CONFERENCE SERIES : NEW SERIES LA English DT Proceedings Paper CT 3rd International Conference on Approximations and Numerical Methods for the Solution of Maxwells Equations CY APR, 1995 CL UNIV OXFORD, ST JOHNS COLL, OXFORD, ENGLAND SP Inst Math & Applicat HO UNIV OXFORD, ST JOHNS COLL AB A benchmark set consisting of a radiating electric dipole, square wave guide, and scattered fields around a perfectly conducting sphere were successfully simulated on a 256-node Intel Paragon XP/S. The one-dimensional domain decomposition strategy was adopted to map a characteristic-based finite-volume numerical procedure onto the parallel computer to achieve an estimated data processing rate of 1.58 Gigaflops. The numerical accuracy of all simulations have been validated by comparison with theoretical results. C1 USAF, Wright Lab, Wright Patterson AFB, OH 45433 USA. RP Shang, JS (reprint author), USAF, Wright Lab, Wright Patterson AFB, OH 45433 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU CLARENDON PRESS PI OXFORD PA WALTON ST, OXFORD OX2 6DP, OXON, ENGLAND BN 0-19-851483-2 J9 INST MATH C PY 1998 VL 65 BP 341 EP 361 PG 21 WC Mathematics, Applied; Mathematics SC Mathematics GA BK99J UT WOS:000074024400021 ER PT J AU Olszewski, AD Miller, MD Ritchie, JR AF Olszewski, AD Miller, MD Ritchie, JR TI Ideal tibial tunnel length for endoscopic anterior cruciate ligament reconstruction SO ARTHROSCOPY LA English DT Article DE anterior cruciate ligament reconstruction; single incision; surgical technique; tunnel preparation ID ACL RECONSTRUCTION; PLACEMENT AB A successful single-incision endoscopic anterior cruciate ligament reconstruction using bone-patellar tendon-bone autograft requires attention to many technical details. The emphasis of placing the femoral bone plug flush with the opening of the femoral tunnel results in distal shift of the graft. Longer tibial tunnels are required to prevent excessive graft extrusion. The purpose of this study is to compare four direct and indirect measurement methods of tibial tunnel preparation to determine which method can be used to create consistently reproducible tibial tunnels that prevent excessive extrusion or recession of the graft within the tunnel. Tunnels placed at the empiric angles of 40 degrees, 50 degrees, and 60 degrees to the tibial plateau resulted in the incidence of acceptable tibial tunnel lengths of 44%, 83%, and 39%, respectively. Tunnels placed at an angle determined by the formula "N + 7" where 7 degrees is added to the patellar tendon length (N) resulted in acceptable tunnels 89% of the time. Direct measurement methods using the formulas "graft - 50 mm" and "N + 2 mm" resulted in acceptable tibial tunnels of 44% and 100%, respectively. We recommend using the "N + 7" in conjunction with the "N + 2 mm" formula to obtain the advantages of both indirect and direct measurement methods. C1 Wilford Hall USAF Med Ctr, Dept Orthopaed, Lackland AFB, TX 78236 USA. Uniformed Serv Univ Hlth Sci, Bethesda, MD 20814 USA. Univ Colorado, USAF, Colorado Springs, CO USA. Dept Orthopaed, Wright Patterson AFB, OH USA. RP Olszewski, AD (reprint author), USAF, MC, FS, 9903 Cinnamon Ridge, San Antonio, TX 78251 USA. NR 8 TC 30 Z9 30 U1 1 U2 1 PU W B SAUNDERS CO PI PHILADELPHIA PA INDEPENDENCE SQUARE WEST CURTIS CENTER, STE 300, PHILADELPHIA, PA 19106-3399 USA SN 0749-8063 J9 ARTHROSCOPY JI Arthroscopy PD JAN-FEB PY 1998 VL 14 IS 1 BP 9 EP 14 DI 10.1016/S0749-8063(98)70114-8 PG 6 WC Orthopedics; Surgery SC Orthopedics; Surgery GA YV325 UT WOS:000071811900004 PM 9486327 ER PT J AU Miller, MD AF Miller, MD TI Revision cruciate ligament surgery with retention of femoral interference screws SO ARTHROSCOPY LA English DT Article DE revision cruciate ligament; interference screws AB As the popularity of cruciate ligament reconstruction continues to escalate, the need for revision surgery has also increased. Revision cruciate ligament surgery is often associated with difficult technical challenges including removing previously placed femoral interference screws. Not only can this hardware be difficult to remove, interference screw extraction often creates a large bony defect immediately adjacent to the revised femoral tunnel that can jeopardize the fixation of the new cruciate ligament graft. It is often possible to perform revision cruciate ligament reconstruction without removing femoral interference screws. This technical note provides several examples of this technique. Routine removal of femoral interference screws during revision cruciate ligament surgery is often not necessary. C1 USAF Acad, Colorado Springs, CO 80840 USA. RP Miller, MD (reprint author), USAF, Med Ctr, 59th Med Wing,MKFO,220 Bergquist Dr,Suite 1, Lackland AFB, TX 78236 USA. NR 4 TC 11 Z9 11 U1 0 U2 0 PU W B SAUNDERS CO PI PHILADELPHIA PA INDEPENDENCE SQUARE WEST CURTIS CENTER, STE 300, PHILADELPHIA, PA 19106-3399 USA SN 0749-8063 J9 ARTHROSCOPY JI Arthroscopy PD JAN-FEB PY 1998 VL 14 IS 1 BP 111 EP 114 DI 10.1016/S0749-8063(98)70134-3 PG 4 WC Orthopedics; Surgery SC Orthopedics; Surgery GA YV325 UT WOS:000071811900024 PM 9486347 ER EF