FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Cooper, BT Parent, D Buckner, SW AF Cooper, BT Parent, D Buckner, SW TI Oxidation reactions and photochemistry of aluminum cluster anions (Al-3(-) to Al-23(-)) SO CHEMICAL PHYSICS LETTERS LA English DT Article ID COLLISION-INDUCED DISSOCIATION; RESONANCE MASS-SPECTROMETRY; METAL-CLUSTERS; IONS; OXYGEN; PHOTODISSOCIATION; CHEMISORPTION; SPECTROSCOPY; BARRIERS; ENERGIES AB Reactions of mass-selected Al-n(-) (n = 3-23) with O-2 produce AlO2-, AlO-, and electron detachment (n less than or equal to 8); or Al-n-4(-) (n = 8-12, 14-22) and sequential dissociation products. All clusters except Al-13(-) absorb at 1064 nm, losing one atom or electron. Several clusters require sequential absorption of two 1064 nm photons to dissociate. Single-photon excitation of Al-16(-) and Al-18(-) retards their oxidation reactions by factors of 2.5 +/- 1.0 and 5.0 +/- 2.0, respectively. Radiative relaxation of Al-16(-) proceeds with a rate constant of 0.47 +/- 0.10 s(-1), measured by the return to thermal reaction behavior. (C) 1998 Elsevier Science B.V. C1 Univ Arizona, Dept Chem, Tucson, AZ 85721 USA. USN, Res Lab, Div Chem, Washington, DC 20375 USA. RP Buckner, SW (reprint author), Columbus State Univ, Dept Chem & Geol, Columbus, GA 31907 USA. NR 27 TC 25 Z9 25 U1 1 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD MAR 6 PY 1998 VL 284 IS 5-6 BP 401 EP 406 DI 10.1016/S0009-2614(97)01432-2 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA ZF810 UT WOS:000072935500017 ER PT J AU Chapman, RD Welker, MF Kreutzberger, CB AF Chapman, RD Welker, MF Kreutzberger, CB TI Defluorination of heterocyclic ketones: Control of microbasicity SO JOURNAL OF ORGANIC CHEMISTRY LA English DT Article ID DENSITY CHARACTERISTICS; <4>PERISTYLANE; DERIVATIVES AB Difluoramination of a tetrahydro-1,5-diazocine-3,7(2H, 6H)-dione to the corresponding 3,3,7,7-tetrakis(difluoramino)diazocine was achieved by a judicious choice of protecting group. Arenesulfonyl protecting groups for the diazocine nitrogens proved superior to acetyl during the slow disruption of the transannular bridge in 9-oxa-3,7-diazabicyclo[3.3.1]nonane intermediates by difluorosulfamic acid, While a 1,5-ditosyl derivative failed to proceed beyond the product of addition of difluoramine to one ketone carbonyl (hemiaminal 6), the use of 4-nitrobenzenesulfonyl as the protecting groups lowered the nitrogens' basicities below that of the oxygen site in the dione and intermediates, allowing the reaction to proceed to a gem-bis(difluoramino)diazocine product (11). A safer procedure for handling difluoramine is described. C1 USN, Air Warfare Weap div, Res & Technol Grp, China Lake, CA 93555 USA. TPL Inc, Albuquerque, NM 87109 USA. RP Chapman, RD (reprint author), USN, Air Warfare Weap div, Res & Technol Grp, Code 4B22001, China Lake, CA 93555 USA. NR 43 TC 16 Z9 17 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0022-3263 J9 J ORG CHEM JI J. Org. Chem. PD MAR 6 PY 1998 VL 63 IS 5 BP 1566 EP 1570 DI 10.1021/jo9718399 PG 5 WC Chemistry, Organic SC Chemistry GA ZC310 UT WOS:000072564300029 ER PT J AU Witkowski, FX Leon, LJ Penkoske, PA Giles, WR Spano, ML Ditto, WL Winfree, AT AF Witkowski, FX Leon, LJ Penkoske, PA Giles, WR Spano, ML Ditto, WL Winfree, AT TI Spatiotemporal evolution of ventricular fibrillation SO NATURE LA English DT Article ID MECHANISMS; MUSCLE AB Sudden cardiac death is the leading cause of death in the industrialized world, with the majority of such tragedies being due to ventricular fibrillation(1). Ventricular fibrillation is a frenzied and irregular disturbance of the heart rhythm that quickly renders the heart incapable of sustaining life. Rotors, electrophysiological structures that emit rotating spiral waves, occur in several systems that all share with the heart the functional properties of excitability and refractoriness, These re-entrant waves, seen in numerical solutions of simplified models of cardiac tissue(2), may occur during ventricular tachycardias(3,4). It has been difficult to detect such forms of re-entry in fibrillating mammalian ventricles(5-8). Here we show that, in isolated perfused dog hearts, high spatial and temporal resolution mapping of optical transmembrane potentials can easily detect transiently erupting rotors during the early phase of ventricular fibrillation, This activity is characterized by a relatively high spatiotemporal cross-correlation. During this early fibrillatory interval, frequent wavefront collisions and wavebreak generation(9) are also dominant features. Interestingly, this spatiotemporal pattern undergoes an evolution to a less highly spatially correlated mechanism that lacks the epicardial manifestations of rotors despite continued myocardial perfusion. C1 Univ Alberta, Dept Med, Edmonton, AB T6G 2R7, Canada. Univ Alberta, Dept Surg, Edmonton, AB T6G 2R7, Canada. Ecole Polytech, Montreal, PQ H3C 3J7, Canada. Univ Calgary, Dept Physiol & Biophys, Calgary, AB T2N 4N1, Canada. USN, Ctr Surface Warfare, Bethesda, MD 20817 USA. Georgia Inst Technol, Sch Phys, Appl Chaos Lab, Atlanta, GA 30332 USA. Univ Arizona, Dept Ecol & Evolut Biol, Tucson, AZ 85721 USA. RP Univ Alberta, Dept Med, Edmonton, AB T6G 2R7, Canada. EM fwitkows@gpu.srv.ualberta.ca RI Spano, Mark/B-6883-2011 NR 15 TC 325 Z9 337 U1 1 U2 21 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 EI 1476-4687 J9 NATURE JI Nature PD MAR 5 PY 1998 VL 392 IS 6671 BP 78 EP 82 DI 10.1038/32170 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA ZA528 UT WOS:000072373000053 PM 9510250 ER PT J AU Hansen, DC Corcoran, SG Waite, JH AF Hansen, DC Corcoran, SG Waite, JH TI Enzymatic tempering of a mussel adhesive protein film SO LANGMUIR LA English DT Article ID MYTILUS-EDULIS-L; OXIDASE; BYSSUS; DOPA; NMR AB An adhesive protein isolated from the marine mussel Mytilus edulis has been adsorbed to highly oriented pyrolytic graphite and enzymatically oxidized to yield a sclerotized film that is tightly bound to the substrate. Atomic force microscopy was used to image the surface and the adsorbed biopolymer, indicating uniform coverage of the substrate within 1 s of adsorption time from solution. Film thicknesses of the adsorbed protein films were estimated to be 25 and 73 Angstrom for the sclerotized films. Imaging forces ranging from less than or equal to 20 to greater than or equal to 600 nN were used to determine the stability of adhesive protein films without and with added catechol oxidase, respectively. Results indicate that the resistance of adhesive protein films to displacement can be enhanced 10-fold by enzymatic oxidation. Oxidation presumably leads to formation of covalent crosslinks between adsorbed protein chains. C1 EG&G Idaho Inc, Oak Ridge, TN 37831 USA. USN, Res Lab, Washington, DC 20375 USA. Univ Delaware, Dept Chem & Biochem, Newark, DE 19716 USA. RP Hansen, DC (reprint author), EG&G Idaho Inc, Oak Ridge, TN 37831 USA. NR 23 TC 36 Z9 36 U1 0 U2 13 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD MAR 3 PY 1998 VL 14 IS 5 BP 1139 EP 1147 DI 10.1021/la970881w PG 9 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA ZA685 UT WOS:000072390800026 ER PT J AU Hobart, KD Twigg, ME Kub, FJ Desmond, CA AF Hobart, KD Twigg, ME Kub, FJ Desmond, CA TI Characterization of Si pn junctions fabricated by direct wafer bonding in ultra-high vacuum SO APPLIED PHYSICS LETTERS LA English DT Article ID SILICON AB The electrical characteristics of pn junctions formed by direct bonding of silicon wafers in ultra-high vacuum have been quantified. The bonding process produces low reverse leakage <1 mu A/cm(2) and near-ideal forward current. The observation of bulk-like bonded interfaces is supported by transmission electron microscopy and infra-red transmission imaging. (C) 1998 American Institute of Physics. C1 USN, Res Lab, Washington, DC 20375 USA. Calif State Univ Sacramento, Sacramento, CA 95819 USA. RP USN, Res Lab, Washington, DC 20375 USA. EM hobart@estd.nrl.navy.mil NR 14 TC 21 Z9 21 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0003-6951 EI 1077-3118 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD MAR 2 PY 1998 VL 72 IS 9 BP 1095 EP 1097 DI 10.1063/1.120975 PG 3 WC Physics, Applied SC Physics GA YZ775 UT WOS:000072290400033 ER PT J AU Henderson, DR AF Henderson, DR TI Technological upheavals - How distance is dying SO FORTUNE LA English DT Article C1 USN, Postgrad Sch, Monterey, CA 93940 USA. RP Henderson, DR (reprint author), USN, Postgrad Sch, Monterey, CA 93940 USA. NR 0 TC 1 Z9 1 U1 1 U2 2 PU TIME INC PI NEW YORK PA TIME & LIFE BUILDING ROCKEFELLER CENTER, NEW YORK, NY 10020-1393 USA SN 0015-8259 J9 FORTUNE JI Fortune PD MAR 2 PY 1998 VL 137 IS 4 BP 44 EP + PG 2 WC Business SC Business & Economics GA YW342 UT WOS:000071925100025 ER PT J AU Feyedelem, MS Sarpkaya, T AF Feyedelem, MS Sarpkaya, T TI Free- and near-free-surface swirling turbulent jets SO AIAA JOURNAL LA English DT Article; Proceedings Paper CT AIAA 35th Aerospace Science Meeting/Nonlinear Dynamical Systems Symposium CY JAN 06-10, 1997 CL RENO, NV SP Amer Inst Aeronaut & Astronaut, USAF, Off Sci Res, Sandia Natl Labs ID VORTEX; FLOWS; ROTATION AB The turbulent flowfield created by a round swirling jet issuing from a nozzle, beneath and parallel to a free surface, in both the deep-and shallow-submergence modes has been studied for three swirl numbers (S = 0.265, 0.500, and 0.522) and fixed Froude and Reynolds numbers using a three-component laser Doppler velocimetry system. The results have shown that a swirling jet is unique among all shear flows; stagnation occurs without vortex breakdown at a critical swirl of S = 0.50; vortex breakdown occurs for S greater than or equal to 0.51 and leads to the intensification of turbulence within or near the exit of the nozzle and to the nonmonotonic change of the turbulent kinetic energy with S; turbulence shear stresses exhibit anisotropic behavior, especially in the plane bisecting the jet; and the degree of anisotropy at the free surface depends on the degree of agitation of the free surface (swirl number, Froude number, rid, and Reynolds number). The need for a robust turbulence model that can deal with the alteration of turbulence by distortion and rotation is emphasized. C1 USN, Postgrad Sch, Dept Mech Engn, Monterey, CA 93943 USA. RP Feyedelem, MS (reprint author), USN, Postgrad Sch, Dept Mech Engn, Monterey, CA 93943 USA. NR 31 TC 4 Z9 4 U1 0 U2 1 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 MAR PY 1998 VL 36 IS 3 BP 359 EP 364 DI 10.2514/2.404 PG 6 WC Engineering, Aerospace SC Engineering GA YZ480 UT WOS:000072258300008 ER PT J AU Chandrasekhara, MS Wilder, MC Carr, LW AF Chandrasekhara, MS Wilder, MC Carr, LW TI Competing mechanisms of compressible dynamic stall SO AIAA JOURNAL LA English DT Article; Proceedings Paper CT AIAA 27th Fluid Dynamics Conference CY JUN 17-20, 1996 CL NEW ORLEANS, LOUISIANA SP Amer Inst Aeronaut & Astronaut ID FLOW AB Earlier experiments have documented the onset of compressible dynamic stall either from the bursting of a leading-edge laminar separation bubble or from a leading-edge shock, depending on the Reynolds number and Mach number, For certain combinations of conditions, the supersonic flow and the bubble dynamics compete with each other. The consequent complex interactions lead to a newly discovered mechanism of dynamic stall onset, Details of these various mechanisms are discussed. C1 USN, Postgrad Sch, Monterey, CA 93943 USA. RP Chandrasekhara, MS (reprint author), USN, Postgrad Sch, Monterey, CA 93943 USA. NR 13 TC 14 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 0001-1452 J9 AIAA J JI AIAA J. PD MAR PY 1998 VL 36 IS 3 BP 387 EP 393 DI 10.2514/2.375 PG 7 WC Engineering, Aerospace SC Engineering GA YZ480 UT WOS:000072258300012 ER PT J AU Venkataramani, A Strong, RM Anderson, DS Gilmore, IT Stokes, K Hofmann, AF AF Venkataramani, A Strong, RM Anderson, DS Gilmore, IT Stokes, K Hofmann, AF TI Abnormal duodenal bile composition in patients with acalculous chronic cholecystitis SO AMERICAN JOURNAL OF GASTROENTEROLOGY LA English DT Article AB Objective: Our goal was to characterize biliary lipid composition in patients with the syndrome of chronic biliary pain, absence of gallstones, and inflammation of the gallbladder mucosa (acalculous chronic cholecystitis), Methods: Duodenal bile, obtained from 27 patients with a history of right upper quadrant pain and with negative imaging studies of the biliary tract, was analyzed enzymatically for bile acids, phospholipids, and cholesterol, Fifteen patients were found to have inflammation and/or fibrosis of the gallbladder at cholecystectomy, Results: The 15 patients with abnormal gallbladder histology had more dilute duodenal bile, as indicated by a low bile acid concentration and a lower proportion of phospholipids (p < 0.01) when values were compared with those of duodenal bile samples from postmenopausal women without gallbladder disease or from radiolucent gallstone subjects participating in the National Cooperative Gallstone Study. Cholecystectomy relieved pain in 9 of 14 patients. Conclusions: Some patients with acalculous chronic cholecystitis have duodenal bile samples characterized by a decreased bile acid concentration and a decreased proportion of biliary phospholipids. The low biliary bile acid concentration may result from impaired gallbladder contraction and/or secretion by the biliary tract epithelium, The low proportion of phospholipid may result from posthepatic hydrolysis of luminal phosphatidylcholine followed by absorption of the hydrolysis products. The latter process could be caused by and/or contribute to mucosal inflammation and would also elevate the cholesterol saturation of bile, increasing the risk for cholesterol gallstone formation. (C) 1998 by Am. Cell. of Gastroenterology. C1 Univ Calif San Diego, Div Gastroenterol, Dept Med, San Diego, CA 92103 USA. USN Hosp, Dept Gastroenterol, San Diego, CA 92134 USA. RP Hofmann, AF (reprint author), Univ Calif San Diego, Div Gastroenterol, Dept Med, 200 W Arbor Dr, San Diego, CA 92103 USA. FU NIDDK NIH HHS [DK 21506] NR 5 TC 7 Z9 8 U1 0 U2 0 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 0002-9270 J9 AM J GASTROENTEROL JI Am. J. Gastroenterol. PD MAR PY 1998 VL 93 IS 3 BP 434 EP 441 PG 8 WC Gastroenterology & Hepatology SC Gastroenterology & Hepatology GA ZJ239 UT WOS:000073194100038 PM 9517653 ER PT J AU Wax, JR Gallagher, MW Eggleston, MK AF Wax, JR Gallagher, MW Eggleston, MK TI Adjunctive color Doppler ultrasonography in second-trimester transabdominal amnioinfusion SO AMERICAN JOURNAL OF OBSTETRICS AND GYNECOLOGY LA English DT Article DE amniocentesis; amnioinfusion; oligohydramnios; Doppler ultrasonography AB Transabdominal amnioinfusion improves the diagnostic accuracy of ultrasonography in pregnancies complicated by second-trimester oligohydramnios. Needle localization may be difficult because of patient obesity or the absence of an acoustic window. The two cases presented demonstrate that color Doppler imaging facilitates amnioinfusion by visualizing the injection jet of free-flowing infusate, confirming intraamniotic needle placement. C1 Hartford Hosp, Dept Obstet & Gynecol, Div Maternal Fetal Med, Hartford, CT 06115 USA. Natl Naval Med Ctr, Bethesda, MD 20889 USA. USN, Med Ctr, Washington, DC USA. RP Wax, JR (reprint author), Hartford Hosp, Dept Obstet & Gynecol, Div Maternal Fetal Med, Hartford, CT 06115 USA. NR 1 TC 2 Z9 2 U1 0 U2 0 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 MAR PY 1998 VL 178 IS 3 BP 622 EP 623 DI 10.1016/S0002-9378(98)70454-5 PG 2 WC Obstetrics & Gynecology SC Obstetrics & Gynecology GA ZE901 UT WOS:000072843000043 PM 9539541 ER PT J AU Driben, JS Bolger, WE Robles, HA Cable, B Zinreich, SJ AF Driben, JS Bolger, WE Robles, HA Cable, B Zinreich, SJ TI The reliability of computerized tomographic detection of the Onodi (sphenoethmoid) cell SO AMERICAN JOURNAL OF RHINOLOGY LA English DT Article ID MAJOR COMPLICATIONS; SINUS SURGERY; OPTIC-NERVE; NASAL AB Optic nerve injury is a devastating potential complication of endoscopic sinus surgery. Anatomic variations of the posterior ethmoid sinus are certainly contributing factors. In the most well described posterior ethmoid anatomical variant, the sphenoethmoid or Onodi cell, the optic nerve is placed at risk during sinus surgery. Improving preoperative and intraoperative identification of the sphenoethmoid (Onodi) cell could decrease the risk of optic nerve injury. The purpose of this investigation was to assess the reliability of computerized tomography (CT) in detecting the sphe noethmoid (Onodi) cell, and further our understanding of this clinically relevant anatomic variant. A total of 41 sinonasal complexes from 21 human adult cadaveric heads were studied with a standard coronal and axial plane CT, and subsequent endoscopic dissection. The prevalence of the sphenoethmoid (Onodi) cell was determined by CT and endoscopic dissection, as were other anatomic characteristics of the posterior ethmoid anatomy. In our study, CT identified a sphenoethmoid (Onodi) cell in 3/41 (7%) of the sphenoethmoid complexes. However, anatomic dissection identified a sphenoethmoid (Onodi) cell in 16/41 (39%) complexes. Coronal orientation of the anterior sphenoid wall was never associated with a sphenoethmoid (Onodi) cell. Conversely, oblique or horizontal orientations were present in all cases of sphenoethmoid (Onodi) cells. Current CT scanning protocols for the paranasal sinuses did not reliably detect the Onodi cell. Endoscopic dissection indicates that the sphenoethmoid (Onodi) cell is a more frequent anatomic variant than previously appreciated. Awareness of anterior sphenoid wall orientation may assist surgeons in identifying the Onodi cell, thereby reducing the risk of optic nerve trauma. C1 Natl Naval Med Ctr, Dept Otolaryngol, Bethesda, MD USA. RP Driben, JS (reprint author), USN Hosp, Dept Otolaryngol, Camp Lejeune, NC 28542 USA. NR 19 TC 34 Z9 39 U1 0 U2 0 PU OCEAN SIDE PUBLICATIONS INC PI PROVIDENCE PA 95 PITMAN ST, PROVIDENCE, RI 02906 USA SN 1050-6586 J9 AM J RHINOL JI Am. J. Rhinol. PD MAR-APR PY 1998 VL 12 IS 2 BP 105 EP 111 DI 10.2500/105065898781390325 PG 7 WC Otorhinolaryngology SC Otorhinolaryngology GA ZK122 UT WOS:000073287500006 PM 9578928 ER PT J AU Gray, GC Fogle, EF Albright, KL AF Gray, GC Fogle, EF Albright, KL TI Risk factors for primary pulmonary coccidioidomycosis hospitalizations among United States Navy and Marine Corps personnel, 1981-1994 SO AMERICAN JOURNAL OF TROPICAL MEDICINE AND HYGIENE LA English DT Article ID OUTBREAK; RECRUITS; ARMY AB Recent coccidioidomycosis outbreaks among military personnel have alarmed public health officials. Wt: used computerized hospitalization records to identify risk factors fbr coccidioidomycosis hospitalizations among active-duty United States Navy and Marine Corps personnel for the years 1981 to 1994. Primary pulmonary disease was the most common form of disease, accounting for 82 (73%) of the 113 first admissions. Crude annual rates of primary pulmonary disease increased markedly in 1992, and 1993 in concert with an epidemic in the United States. Demographic data from the pulmonary admissions were combined with that of a 2% random sample of the entire Navy and Marine Corps population for multivariate risk factor modeling. Persons from junior paygrades, older age groups, and those reporting a race/ethnicity other than Caucasian or Hispanic were most likely to be hospitalized with this disease. These risk factor data should be considered in designing coccidioidomycosis surveillance and prevention programs. C1 USN, Hlth Res Ctr, Emerging Illness Div, San Diego, CA 92186 USA. Vanderbilt Univ, Sch Med, Nashville, TN 37212 USA. RP Gray, GC (reprint author), USN, Hlth Res Ctr, Emerging Illness Div, POB 85122, San Diego, CA 92186 USA. NR 27 TC 14 Z9 14 U1 1 U2 1 PU AMER SOC TROP MED & HYGIENE PI MCLEAN PA 8000 WESTPARK DRIVE SUITE 130, MCLEAN, VA 22101 USA SN 0002-9637 J9 AM J TROP MED HYG JI Am. J. Trop. Med. Hyg. PD MAR PY 1998 VL 58 IS 3 BP 309 EP 312 PG 4 WC Public, Environmental & Occupational Health; Tropical Medicine SC Public, Environmental & Occupational Health; Tropical Medicine GA ZF396 UT WOS:000072893300009 PM 9546408 ER PT J AU Bigham, WJ Christensen, GR Fulcher, SF AF Bigham, WJ Christensen, GR Fulcher, SF TI Relapsing polychondritis associated with cutaneous polyarteritis nodosa presenting as orbital cellulitis SO ANNALS OF OPHTHALMOLOGY & GLAUCOMA LA English DT Article ID PERIARTERITIS-NODOSA; ANTIBODIES; COLLAGEN AB An elderly gentleman had a constellation of inflammatory disease findings with features of relapsing polychondritis, cutaneous polyarteritis nodosa, and orbital inflammation. Initial clinical signs were suggestive of orbital abscess; however, his ocular findings were preceded by painful subcutaneous nodules mistakenly thought to be thrombophlebitis. This case illustrates that different rheumatic diseases share many common ancillary findings, which may not only dominate the clinical picture but antedate the onset of the complete symptom complex by months or years. These diseases frequently involve ocular structures and this involvement may be the presenting symptom. C1 USN, Med Ctr, Dept Ophthalmol, San Diego, CA 92152 USA. USN, Med Ctr, Dept Clin Invest, San Diego, CA 92152 USA. RP Christensen, GR (reprint author), Natl Naval Med Ctr, Dept Ophthalmol, Bethesda, MD 20889 USA. NR 24 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC CONTEMPORARY OPHTHALMOLOGY PI SKOKIE PA 4711 GOLF RD, SUITE 408, SKOKIE, IL 60076-1242 USA SN 1079-4794 J9 ANN OPHTHALMOL GLAUC JI Ann. Ophthalmol. Glaucoma PD MAR-APR PY 1998 VL 30 IS 2 BP 102 EP 106 PG 5 WC Ophthalmology SC Ophthalmology GA ZL127 UT WOS:000073401500013 ER PT J AU Postma, GN Shockley, WW AF Postma, GN Shockley, WW TI Transient vocal fold immobility SO ANNALS OF OTOLOGY RHINOLOGY AND LARYNGOLOGY LA English DT Article DE laryngeal paralysis; vocal cord; vocal fold ID RECURRENT LARYNGEAL NERVE; SYSTEMIC LUPUS-ERYTHEMATOSUS; CORD PARALYSIS; STRIDOR; PALSY; SECONDARY; PARESIS AB Temporary vocal fold immobility resolving in 4 weeks or less is considered a transient immobility. Many different disorders may lead to this type of laryngeal motion impairment. It is important for otolaryngologists to be familiar with the differential diagnosis for transient vocal fold immobility in order to optimize the management of these unusual cases. C1 Univ N Carolina, Div Otolaryngol Head & Neck Surg, Chapel Hill, NC 27515 USA. USN, Med Ctr Portsmouth, Dept Otolaryngol Head & Neck Surg, Portsmouth, VA USA. RP Postma, GN (reprint author), Wake Forest Univ, Sch Med, Dept Otolaryngol, Ctr Voice Disorders, Med Ctr Blvd, Winston Salem, NC 27157 USA. NR 32 TC 8 Z9 8 U1 0 U2 0 PU ANNALS PUBL CO PI ST LOUIS PA 4507 LACLEDE AVE, ST LOUIS, MO 63108 USA SN 0003-4894 J9 ANN OTO RHINOL LARYN JI Ann. Otol. Rhinol. Laryngol. PD MAR PY 1998 VL 107 IS 3 BP 236 EP 240 PG 5 WC Otorhinolaryngology SC Otorhinolaryngology GA ZC176 UT WOS:000072548400009 PM 9525246 ER PT J AU Seely, JF Holland, GE Boehly, T Pien, G Bradley, D AF Seely, JF Holland, GE Boehly, T Pien, G Bradley, D TI Uniformity of the soft-x-ray emissions from gold foils irradiated by OMEGA laser beams determined by a two-mirror normal-incidence microscope with multilayer coatings SO APPLIED OPTICS LA English DT Article ID COMPRESSION; PLASMAS; FUSION AB A two-mirror normal-incidence microscope with multilayer coatings was used to image the soft-x-ray-emissions from planar foils irradiated by OMEGA laser beams. The bandpass of the multilayer coatings was centered at a wavelength of 48.3 Angstrom (257-eV energy) and was 0.5 Angstrom wide. Five overlapping OMEGA beams, without beam smoothing, were typically incident on the gold foils. The total energy was 1500 J, and the focused intensity was 6 x 10(13) W cm(-2). The 5.8x magnified images were recorded by a gated framing camera at various times during the 3-ns laser pulse. A pinhole camera imaged the x-ray emission in the energy range of >2 keV. On a spatial scale of 10 mu m, it was found that the soft-x-ray; images at 257 eV were quite uniform and featureless. In contrast, the hard-x-ray images in the energy range of >2 keV were highly nonuniform with numerous features of size 150 mu m. C1 USN, Res Lab, EO Hulburt Ctr Space Res, Washington, DC 20375 USA. SFA Inc, Landover, MD 20785 USA. Univ Rochester, Laser Energet Lab, Rochester, NY 14623 USA. RP Seely, JF (reprint author), USN, Res Lab, EO Hulburt Ctr Space Res, Washington, DC 20375 USA. NR 12 TC 4 Z9 8 U1 1 U2 2 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 MAR 1 PY 1998 VL 37 IS 7 BP 1140 EP 1145 DI 10.1364/AO.37.001140 PG 6 WC Optics SC Optics GA YY886 UT WOS:000072197000002 PM 18268696 ER PT J AU Van Dyk, SD Montes, MJ Weiler, KW Sramek, RA Panagia, N AF Van Dyk, SD Montes, MJ Weiler, KW Sramek, RA Panagia, N TI Radio detection of SN 1985L in NGC 5033 SO ASTRONOMICAL JOURNAL LA English DT Article DE supernovae, individual (SN 1985L) ID OPTICAL-EMISSION; SUPERNOVAE; RECOVERY; SN-1980K; SN-1979C; REMNANT; 1957D; M100; M83 AB Observations of SN 1985L in NGC 5033 with the Very Large Array radio telescope have resulted in two detections of radio emission at 6 cm wavelength about 8 and 16 months after optical discovery. Combined with a number of upper limits and a study of possible models, these indicate that SN 1985L was probably a fairly normal Type II-L radio supernova, somewhat intermediate in radio properties between the well-studied radio supernovae SN 1979C and SN 1980K. A possible late-time optical detection, discussed in an accompanying paper by Fesen (1998), continues the observed correlation between radio and late-time optical emission. C1 Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. USN, Res Lab, Remote Sensing Div, Washington, DC 20375 USA. Natl Radio Astron Observ, Socorro, NM 87801 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. ESA, Dept Space Sci, Div Astrophys, F-75738 Paris 15, France. RP Van Dyk, SD (reprint author), Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. RI Montes, Marcos/J-9239-2015 OI Montes, Marcos/0000-0002-4725-5380 NR 28 TC 6 Z9 6 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5801 S ELLIS AVENUE, CHICAGO, IL 60637 USA SN 0004-6256 J9 ASTRON J JI Astron. J. PD MAR PY 1998 VL 115 IS 3 BP 1103 EP 1106 DI 10.1086/300261 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA ZB173 UT WOS:000072443700019 ER PT J AU Pascu, D Rohde, JR Seidelmann, PK Wells, EN Kowal, CT Zellner, BH Storrs, AD Currie, DG Dowling, DM AF Pascu, D Rohde, JR Seidelmann, PK Wells, EN Kowal, CT Zellner, BH Storrs, AD Currie, DG Dowling, DM TI Hubble Space Telescope astrometric observations and orbital mean motion corrections for the inner uranian satellites SO ASTRONOMICAL JOURNAL LA English DT Article DE celestial mechanics, stellar dynamics; planets and satellites, individual (Uranus) ID RINGS AB The 10 small inner satellites of Uranus were discovered in 1986 with Voyager 2 and not seen again until 1994, when eight were recovered with the Hubble Space Telescope Wide Field Planetary Camera 2 for astrometric, dynamical, and photometric studies. Thirty-three exposures were taken on 1994 August 14 with the PC1 chip in the BVRI filters. Measurable images of Ariel and Miranda were also obtained on the same CCD frames with those of the faint satellites. We present here the astrometric observations of these eight satellites relative to Miranda, as well as corrected orbital mean motions for them. For the full-well images of Ariel and Miranda, the astrometric limitation was due to an inadequate geometric distortion correction and distance from center. For the faint inner satellites, the astrometric precision varied from 50 mas for Bianca (V = 23 mag) to 9 mas for Puck (V = 20 mag) and was due primarily to a centroiding error caused by a low signal-to-noise ratio. The orbits of Owen & Synnott for the inner satellites were compared with these observations and corrections derived to their mean daily motions. While the orbits of Owen & Synnott proved to be better than their errors indicated, the new mean motions are 2 orders of magnitude more precise. C1 USN Observ, Washington, DC 20392 USA. Comp Sci Corp, Space Telescope Sci Inst, Baltimore, MD 21218 USA. Georgia So Univ, Dept Phys, Statesboro, GA 30460 USA. Univ Maryland, Dept Phys & Astron, College Pk, MD 20742 USA. RP Pascu, D (reprint author), USN Observ, 3450 Massachusetts Ave NW, Washington, DC 20392 USA. NR 8 TC 11 Z9 12 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5801 S ELLIS AVENUE, CHICAGO, IL 60637 USA SN 0004-6256 J9 ASTRON J JI Astron. J. PD MAR PY 1998 VL 115 IS 3 BP 1190 EP 1194 DI 10.1086/300245 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA ZB173 UT WOS:000072443700028 ER PT J AU Urban, SE Corbin, TE Wycoff, GL Martin, JC Jackson, ES Zacharias, MI AF Urban, SE Corbin, TE Wycoff, GL Martin, JC Jackson, ES Zacharias, MI TI The AC 2000: The Astrographic Catalogue on the system defined by the Hipparcos Catalogue SO ASTRONOMICAL JOURNAL LA English DT Article DE astrometry; catalogs; reference systems; surveys ID CONVENTIONAL PLATE ADJUSTMENT; REDUCTIONS; FIELD; CPC2 AB The AC 2000 is a positional catalog of 4,621,836 stars covering the entire sky. The average epoch of position is 1907. The data are from the images measured and published as part of the Astrographic Catalogue (AC). The positions are on the system defined by the Hipparcos Catalogue, having originally been reduced plate-by-plate using the Astrographic Catalog Reference Stars. In addition to the astrometric data, magnitudes (on the Tycho B system) and cross-referencing information are included. These positions are valuable for the computation of proper motions, and were combined with the positions from the recently released Tycho Catalogue to improve proper motions of almost 1 million stars. The resulting catalog is known as the ACT Reference Catalog (the name ACT is from AC 2000 and Tycho). Both the AC 2000 and ACT are now available on CD-ROM and can be obtained by contacting the first author above. A World Wide Web site describing various aspects of the reductions is also maintained by the Astrometry Department, US Naval Observatory. C1 USN Observ, Washington, DC 20392 USA. RP Urban, SE (reprint author), USN Observ, 3450 Massachusetts Ave NW, Washington, DC 20392 USA. NR 30 TC 92 Z9 93 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5801 S ELLIS AVENUE, CHICAGO, IL 60637 USA SN 0004-6256 J9 ASTRON J JI Astron. J. PD MAR PY 1998 VL 115 IS 3 BP 1212 EP 1223 DI 10.1086/300264 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA ZB173 UT WOS:000072443700032 ER PT J AU Platais, I Kozhurina-Platais, V Girard, TM van Altena, WF Lopez, CE Hanson, RB Klemola, AR Jones, BF MacGillivray, HT Yentis, DJ Kovalevsky, J Lindegren, L AF Platais, I Kozhurina-Platais, V Girard, TM van Altena, WF Lopez, CE Hanson, RB Klemola, AR Jones, BF MacGillivray, HT Yentis, DJ Kovalevsky, J Lindegren, L TI The Hipparcos proper motion link to the extragalactic reference system using NPM and SPM SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE astrometry; catalogs; reference systems; methods : data analysis ID CATALOG AB We describe the use of the Lick Northern Proper Motion (NPM) program and its southern-sky complement, the Yale/San Juan Southern Proper Motion (SPM) program, to determine the Hipparcos proper motion link to the extragalactic reference system defined by galaxies. In total similar to 9,100 Hipparcos stars were chosen for the NPM link solution and similar to 4,100 for the SPM solution. The typical accuracy of the NPM absolute proper motions is 5 mas yr(-1). For the SPM proper motions it varies from 2 to 4 mas yr(-1). The link solutions indicate a presence of magnitude equation in both the NPM and SPM. In the case of the NPM three different approaches (i.e., introducing a magnitude cutoff, additional linear magnitude terms, and including a fictitious zone of avoidance) were examined to alleviate the magnitude equation problem. The SPM proper motions show a notable correlation between the postfit residuals and the size of the magnitude equation correction applied. It is quite likely that galaxies have a magnitude equation different from that affecting the stellar images. We note an improvement in the spin solution with re-calibrated galaxy magnitudes and, subsequently, changed magnitude-equation corrections for the galaxies. C1 Yale Univ, Dept Astron, New Haven, CT 06520 USA. Felix Aguilar Observ, San Juan, Argentina. Yale So Observ, San Juan, Argentina. Univ Calif Santa Cruz, Lick Observ, Santa Cruz, CA 95064 USA. Royal Observ, Edinburgh EH9 3HJ, Midlothian, Scotland. USN, Res Lab, Washington, DC 20375 USA. Observ Cote Azur, CERGA, F-06130 Grasse, France. Lund Observ, S-22100 Lund, Sweden. RP Platais, I (reprint author), Yale Univ, Dept Astron, POB 208101, New Haven, CT 06520 USA. NR 18 TC 11 Z9 12 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 1432-0746 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD MAR PY 1998 VL 331 IS 3 BP 1119 EP 1129 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA ZD690 UT WOS:000072713100048 ER PT J AU Dahlburg, RB Antiochos, SK Klimchuk, JA AF Dahlburg, RB Antiochos, SK Klimchuk, JA TI Prominence formation by localized heating SO ASTROPHYSICAL JOURNAL LA English DT Article DE MHD; Sun, corona; Sun, magnetic fields; Sun, prominences ID SOLAR PROMINENCES; TRANSITION REGION; CORONAL LOOP; CONDENSATION; DYNAMICS; FIELDS; MODEL AB We describe a model for the formation of the cool condensed material that comprises a coronal filament or prominence. Numerical calculations are presented which demonstrate that large condensations form in a coronal loop if the loop satisfies two key requirements: (1) the loop heating must be localized near the chromospheric footpoints, and (2) the loop must have a dipped geometry in order to support the prominence condensation against gravity. We calculate one-dimensional equilibrium solutions for the equations of force and energy balance assuming optically thin radiative losses and a parameterized form for the coronal heating. This physical situation is modeled as a boundary value problem, which we solve numerically using a B-spline collocation scheme. The relation of our solutions to the well-known loop scaling laws is discussed, and the implications of our model for active region and quiescent prominences are discussed. C1 USN, Res Lab, Computat Phys & Fluid Dynam Lab, Washington, DC 20375 USA. USN, Res Lab, EO Hulburt Ctr Space Res, Washington, DC 20375 USA. RP USN, Res Lab, Computat Phys & Fluid Dynam Lab, Code 6440, Washington, DC 20375 USA. RI Klimchuk, James/D-1041-2012; Antiochos, Spiro/D-4668-2012 OI Klimchuk, James/0000-0003-2255-0305; Antiochos, Spiro/0000-0003-0176-4312 NR 31 TC 35 Z9 35 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD MAR 1 PY 1998 VL 495 IS 1 BP 485 EP 490 DI 10.1086/305286 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA ZA394 UT WOS:000072359100043 ER PT J AU Karpen, JT Antiochos, SK DeVore, CR Golub, L AF Karpen, JT Antiochos, SK DeVore, CR Golub, L TI Dynamic responses to magnetic reconnection in solar arcades SO ASTROPHYSICAL JOURNAL LA English DT Article DE MHD; Sun, chromosphere; Sun, magnetic fields ID X-RAY JETS; H-ALPHA SURGES; EXPLOSIVE EVENTS; TELESCOPE; FLUX; ACCELERATION; ATMOSPHERE; MECHANISM; FIELDS; MODEL AB We present a numerical simulation of the interaction between two line dipoles through magnetic reconnection in the lower solar atmosphere, a process believed to be the origin of many manifestations of solar activity. This work differs from previous studies in that the held is sheared asymmetrically and that the dipoles have markedly unequal held strengths. This calculation already yielded one key discovery, denoted reconnection driven current filamentation, as described in a previous Astrophysical Journal letter. In this paper we focus on the chromospheric and coronal dynamics resulting from the shear-driven reconnection of unequal dipoles, discuss the important implications for chromospheric eruptions, compare our calculation with high-resolution Normal Incidence X-Ray Telescope observations of a surge, and contrast our results with the predictions of "fast reconnection" models. C1 USN, Res Lab, EO Hulburt Ctr Space Res, Washington, DC 20375 USA. USN, Res Lab, Computat Phys & Fluid Dynam Lab, Washington, DC 20375 USA. Smithsonian Astrophys Observ, Cambridge, MA 02138 USA. RP Karpen, JT (reprint author), USN, Res Lab, EO Hulburt Ctr Space Res, Code 7670, Washington, DC 20375 USA. RI Karpen, Judith/E-1484-2012; Antiochos, Spiro/D-4668-2012; DeVore, C/A-6067-2015; OI Antiochos, Spiro/0000-0003-0176-4312; DeVore, C/0000-0002-4668-591X; Golub, Leon/0000-0001-9638-3082 NR 45 TC 60 Z9 60 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAR 1 PY 1998 VL 495 IS 1 BP 491 EP 501 DI 10.1086/305252 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA ZA394 UT WOS:000072359100044 ER PT J AU Muth, ER Thayer, JF Stern, RM Friedman, BH Drake, C AF Muth, ER Thayer, JF Stern, RM Friedman, BH Drake, C TI The effect of autonomic nervous system activity on gastric myoelectrical activity: does the spectral reserve hypothesis hold for the stomach? SO BIOLOGICAL PSYCHOLOGY LA English DT Article DE autonomic nervous system; gastric myoelectrical activity; spectral reserve hypothesis ID RESPIRATORY SINUS ARRHYTHMIA; INDUCED MOTION SICKNESS; HEART; TONE AB Previous studies have associated changes in gastric myoelectrical activity during motion sickness, as indexed using the electrogastrogram (EGG), with changes in autonomic nervous system (ANS) activity. Subjects who did not report nausea in a rotating optokinetic drum were characterized by normal 3 cycles per minute (cpm) gastric myoelectrical activity, strong parasympathetic nervous system (PNS) activity, and low sympathetic nervous system (SNS) activity. The goals of this study were: (1) to determine whether tasks previously shown to alter ANS activity as indexed by changes in cardiac inter-beat intervals (IBIs) would result in systematic changes in gastric myoelectrical activity in accord with the findings from motion sickness studies; and (2) to determine whether the 'spectral reserve hypothesis' applies to gastric myoelectrical activity. EGGs and IBIs were collected from 24 healthy subjects during resting/baseline, reaction time/shock-avoidance (RT) and cold face stress (CF) tasks. Tachyarrhythmia was found to be significantly greater during the RT task than during the baseline and CF tasks. It was concluded that: (1) tasks that alter ANS activity do systematically alter gastric myoelectrical activity; and (2) gastric myoelectrical activity does not follow the cardiac model of health being associated with increased spectral complexity. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Penn State Univ, Dept Psychol, University Pk, PA 16802 USA. Univ Missouri, Dept Psychol, Quantitat Psychophysiol Lab, Columbia, MO 65211 USA. Virginia Polytech Inst & State Univ, Dept Psychol, Blacksburg, VA 24061 USA. RP Muth, ER (reprint author), USN, Aerosp Med Res Lab, 51 Hovey Rd, Pensacola, FL 32508 USA. NR 32 TC 18 Z9 19 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0301-0511 J9 BIOL PSYCHOL JI Biol. Psychol. PD MAR PY 1998 VL 47 IS 3 BP 265 EP 278 DI 10.1016/S0301-0511(97)00030-6 PG 14 WC Psychology, Biological; Behavioral Sciences; Psychology; Psychology, Experimental SC Psychology; Behavioral Sciences GA ZF623 UT WOS:000072915600005 PM 9564453 ER PT J AU Wadkins, RM Golden, JP Pritsiolas, LM Ligler, FS AF Wadkins, RM Golden, JP Pritsiolas, LM Ligler, FS TI Detection of multiple toxic agents using a planar array immunosensor SO BIOSENSORS & BIOELECTRONICS LA English DT Article DE biosensor; multianalyte; immunoassay; CCD; fluorescence; array ID DYE LABELING REAGENTS; OLIGONUCLEOTIDE ARRAYS; SUCCINIMIDYL ESTERS; BIOSENSOR; FABRICATION; ANTIBODIES; MOLECULES; SURFACES; SUPPORTS AB A planar array immunosensor, equipped with a charge-coupled device (CCD) as a detector, was used to simultaneously detect 3 toxic analytes. Wells approximately 2 mm in diameter were formed on glass slides using a photoactivated optical adhesive. Antibodies against staphylococcal enterotoxin B (SEB), ricin, and Yersinia pestis were covalently attached to the bottoms of the circular wells to form the sensing surface. Rectangular wells containing chicken immunoglobulin were used as alignment markers and to generate control signals. After removing the optical adhesive, the slides were mounted over a scientific grade CCD operating at ambient temperature in inverted (multipin phasing) mode. A two-dimensional graded index of refraction lens at-ray was used to focus the sensing surface onto the CCD. Solutions of toxins were then placed on the slide. After rinsing, Cy5-labeled antibodies were introduced. The identity and amount of toxin bound at each location on the slide were determined by quantitative image analysis. Concentrations as low as 25 ng/mL of ricin, 15 ng/mL of pestis F1 antigen, and 5 ng/mL of SEB could be routinely measured. (C) 1998 Elsevier Science S.A. All rights reserved. C1 USN, Res Lab, Ctr Biomol Sci & Engn, Washington, DC 20375 USA. RP Ligler, FS (reprint author), USN, Res Lab, Ctr Biomol Sci & Engn, Code 6900, Washington, DC 20375 USA. EM fligler@cbmse.nrl.navy.mil NR 24 TC 106 Z9 111 U1 1 U2 9 PU ELSEVIER ADVANCED TECHNOLOGY PI OXFORD PA OXFORD FULFILLMENT CENTRE THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0956-5663 J9 BIOSENS BIOELECTRON JI Biosens. Bioelectron. PD MAR 1 PY 1998 VL 13 IS 3-4 BP 407 EP 415 DI 10.1016/S0956-5663(97)00113-9 PG 9 WC Biophysics; Biotechnology & Applied Microbiology; Chemistry, Analytical; Electrochemistry; Nanoscience & Nanotechnology SC Biophysics; Biotechnology & Applied Microbiology; Chemistry; Electrochemistry; Science & Technology - Other Topics GA ZR002 UT WOS:000073925300015 PM 9642774 ER PT J AU Freitas, JA Moore, WJ AF Freitas, JA Moore, WJ TI Optical studies of undoped and doped wide bandgap carbide and nitride semiconductors SO BRAZILIAN JOURNAL OF PHYSICS LA English DT Article ID CHEMICAL VAPOR-DEPOSITION; CUBIC SILICON-CARBIDE; GAN FILMS; SINGLE-CRYSTALS; GALLIUM NITRIDE; PHOTOLUMINESCENCE; LAYERS; GROWTH; ENERGIES; DONORS AB The wide bandgap semiconductors Silicon carbide and gallium nitride have been studied by Raman scattering, photoluminescence, and infrared absorption. Raman scattering studies determined crystalline quality and polytype of bulk and thin film samples at room temperature. Photoluminescence studies were carried out as a function of temperature to detect and/or identify impurity centers and structure related defects and their role on the electronic properties of the materials. Infrared absorption spectroscopy was used to measure the binding energy of donors and their concentration. C1 USN, Res Lab, Washington, DC 20375 USA. RP Freitas, JA (reprint author), USN, Res Lab, 4555 Overlook Ave SW, Washington, DC 20375 USA. NR 42 TC 7 Z9 7 U1 0 U2 5 PU SOCIEDADE BRASILEIRA FISICA PI SAO PAULO PA CAIXA POSTAL 66328, 05315-970 SAO PAULO, BRAZIL SN 0103-9733 J9 BRAZ J PHYS JI Braz. J. Phys. PD MAR PY 1998 VL 28 IS 1 BP 12 EP 18 PG 7 WC Physics, Multidisciplinary SC Physics GA 135WA UT WOS:000076824600002 ER PT J AU May, DA Parmeter, MM Olszewski, DS McKenzie, BD AF May, DA Parmeter, MM Olszewski, DS McKenzie, BD TI Operational processing of satellite sea surface temperature retrievals at the Naval Oceanographic Office SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article AB A complete overview of the national Shared Processing Program (SPP) satellite sea surface temperature (SST) retrieval product is presented. This paper summarizes the operational processing of digital Advanced Very High Resolution Radiometer (AVHRR) satellite data into a global SST retrieval product at the Naval Oceanographic Office (NAVOCEANO). Satellite SST generation is described, detailing data processing procedures, algorithms used, and quality control techniques. User interaction and data monitoring through the SPP algorithm research panel for SST is presented along with SST products and information available to users. The NAVOCEANO national SST product consists of more than 150000 global retrievals per day and demonstrates monthly bias errors less than 0.1 degrees C and root-mean-square difference errors less than 0.6 degrees C relative to global drifting-buoy measurements. The product is important to and operationally utilized within thermal structure analyses, civilian and military maritime activities, and numerical weather prediction forecasts. C1 USN, Res Lab, Bay St Louis, MS 39529 USA. USN, Oceanog Off, Bay St Louis, MS 39529 USA. RP May, DA (reprint author), USN, Res Lab, Code 7240,Bldg 1105, Bay St Louis, MS 39529 USA. NR 16 TC 71 Z9 74 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD MAR PY 1998 VL 79 IS 3 BP 397 EP 407 DI 10.1175/1520-0477(1998)079<0397:OPOSSS>2.0.CO;2 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZE363 UT WOS:000072785100001 ER PT J AU Bastiaans, LM Smith, DR McPherson, RA Phoebus, PA Moran, JM Croft, PJ Ceritelli, MJ Rao, GV Schaefer, JT Gadomski, FJ Kloesel, KA Quayle, RG Zeitler, JW AF Bastiaans, LM Smith, DR McPherson, RA Phoebus, PA Moran, JM Croft, PJ Ceritelli, MJ Rao, GV Schaefer, JT Gadomski, FJ Kloesel, KA Quayle, RG Zeitler, JW TI The Sixth AMS Symposium on Education SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Editorial Material AB The American Meteorological Society held its Sixth Symposium on Education in conjunction with the 77th Annual Meeting in Long Beach, California. The theme of the symposium was "Atmospheric and Oceanographic Education:Teaching about the Global Environment." Thirty-eight oral presentations and 37 poster presentations summarized a variety of educational programs or examined educational issues for both the precollege and university levels. There was also a joint session with the Eighth Symposium on Global Change Studies and a special session on "home pages" to promote popular meteorological education. Over 200 people representing a wide spectrum of the Society attended one or more of the sessions in this two-day conference where they increased their awareness of teaching about the global environment. C1 USN Acad, Dept Oceanog, Annapolis, MD 21402 USA. Nassau Cty Community Coll, Dept Phys Sci, Garden City, NY USA. Oklahoma Climate Survey, Norman, OK USA. USN, Res Lab, Monterey, CA USA. Univ Wisconsin, Coll Environm Sci, Green Bay, WI 54302 USA. Jackson State Univ, Dept Phys & Atmospher Sci, Jackson, MS USA. Immaculate Concept Sch, Columbus, OH USA. St Louis Univ, Dept Earth & Atmospher Sci, St Louis, MO 63103 USA. Natl Storms Predict Ctr, Norman, OK USA. Penn State Univ, Dept Meteorol, University Pk, PA 16802 USA. Florida State Univ, Dept Meteorol, Tallahassee, FL 32306 USA. Natl Climat Data Ctr, Asheville, NC USA. Natl Weather Serv, Rapid City, SD USA. RP Smith, DR (reprint author), USN Acad, Dept Oceanog, 572 Holloway Rd, Annapolis, MD 21402 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD MAR PY 1998 VL 79 IS 3 BP 457 EP 466 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA ZE363 UT WOS:000072785100006 ER PT J AU Witkowski, FX Leon, LJ Penkoske, PA Clark, RB Spano, ML Ditto, WL Giles, WR AF Witkowski, FX Leon, LJ Penkoske, PA Clark, RB Spano, ML Ditto, WL Giles, WR TI A method for visualization of ventricular fibrillation: Design of a cooled fiberoptically coupled image intensified CCD data acquisition system incorporating wavelet shrinkage based adaptive filtering SO CHAOS LA English DT Article ID ELECTRICAL-ACTIVITY; REENTRANT ACTIVITY; APLYSIA NEURONS; CARDIAC-MUSCLE; RABBIT HEART; SHOCKS AB The measurement of cardiac transmembrane potential changes with voltage sensitive dyes is in increasing use. Detection of these very small fluorescent alterations using large multiplexed arrays, such as charge coupled device (CCD) cameras at high sampling rates, has proven challenging and usually requires significant averaging to improve the signal-to-noise ratio. To minimize the damage of living tissue stained with voltage sensitive dyes, excitation photon exposure must be limited, with the inevitable consequence of diminishing the fluorescence that is generated. State-of-the-art high frame rate CCD cameras have read noise levels in the 5-10 e(-) rms range, which is at least two orders of magnitude above that required to detect voltage sensitive dye alterations at individual pixels corresponding to 1 mm(2) heart regions illuminated with levels of 100 mW/cm(2) at frame rates approaching 1000 frames/sec. Image intensification is thus required prior to photon quantification. We report here the development of such a data acquisition system using commercially available hardware. Additionally, in the past ten years, a mathematical theory of multiresolution has been developed, and new building blocks called wavelets, allow a signal to be observed at different resolutions. Wavelet analysis also makes possible a new method of extricating signals from noise. We have incorporated spatially adaptive filters based on wavelet denoising of individual pixels to significantly reduce the multiple noise sources present in the acquired data. (C) 1998 American Institute of Physics. C1 Univ Alberta, Sch Med, Dept Med, Edmonton, AB, Canada. Univ Montreal, Quebec City, PQ, Canada. Univ Alberta, Sch Med, Dept Surg, Edmonton, AB, Canada. Univ Calgary, Dept Med Physiol, Calgary, AB, Canada. USN, Ctr Surface Warfare, Silver Spring, MD 20817 USA. Georgia Inst Technol, Sch Phys, Atlanta, GA 30332 USA. RP Witkowski, FX (reprint author), Univ Alberta, Sch Med, Dept Med, Edmonton, AB, Canada. RI Spano, Mark/B-6883-2011; OI Ditto, William/0000-0002-7416-8012 NR 23 TC 20 Z9 20 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 1054-1500 J9 CHAOS JI Chaos PD MAR PY 1998 VL 8 IS 1 BP 94 EP 102 DI 10.1063/1.166290 PG 9 WC Mathematics, Applied; Physics, Mathematical SC Mathematics; Physics GA ZC947 UT WOS:000072635100007 ER PT J AU Purdy, AP AF Purdy, AP TI Ammonothermal crystal growth of sulfide materials SO CHEMISTRY OF MATERIALS LA English DT Article ID HYDROTHERMAL SYNTHESIS; SUPERCRITICAL AMINES; METAL AB Single crystals of binary alkaline earth sulfides CaS and SrS and the new ternary copper sulfides NH4Cu4S3 and CaCu2S2 were grown in supercritical anhydrous ammonia at temperatures between 335 and 500 degrees C. The structure of CaCu2S2 is shown. C1 USN, Res Lab, Div Chem, Mat Chem Branch, Washington, DC 20375 USA. RP Purdy, AP (reprint author), USN, Res Lab, Div Chem, Mat Chem Branch, Code 6120, Washington, DC 20375 USA. NR 24 TC 13 Z9 13 U1 3 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD MAR PY 1998 VL 10 IS 3 BP 692 EP + DI 10.1021/cm970674h PG 4 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA ZC940 UT WOS:000072634300005 ER PT J AU DeCredico, MA AF DeCredico, MA TI Beating plowshares into swords: The political economy of American warfare, 1606-1865 SO CIVIL WAR HISTORY LA English DT Book Review C1 USN Acad, Annapolis, MD 21402 USA. RP DeCredico, MA (reprint author), USN Acad, Annapolis, MD 21402 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU KENT STATE UNIV PRESS PI KENT PA C/O JOURNALS DEPT, KENT, OH 44242 USA SN 0009-8078 J9 CIVIL WAR HIST JI Civil War Hist. PD MAR PY 1998 VL 44 IS 1 BP 73 EP 74 PG 2 WC History SC History GA 101CV UT WOS:000074852800017 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 Mizel, MS Temple, HT Michelson, JD Alvarez, RG Clanton, TO Frey, CC Gegenheimer, AP Hurwitz, SR Lutter, LD Mankey, MG Mann, RA Miller, RA Richardson, EG Schon, LC Thompson, FM Yodlowski, ML AF Mizel, MS Temple, HT Michelson, JD Alvarez, RG Clanton, TO Frey, CC Gegenheimer, AP Hurwitz, SR Lutter, LD Mankey, MG Mann, RA Miller, RA Richardson, EG Schon, LC Thompson, FM Yodlowski, ML TI Thromboembolism after foot and ankle surgery - A multicenter study SO CLINICAL ORTHOPAEDICS AND RELATED RESEARCH LA English DT Article ID TOTAL HIP-REPLACEMENT; DEEP-VEIN THROMBOSIS; LOW-DOSE HEPARIN; VENOUS THROMBOEMBOLISM; PROPHYLAXIS; ASPIRIN; ARTHROPLASTY; PREVENTION AB Thromboembolic disease presents a potentially fatal complication to patients undergoing orthopaedic surgery, Although the incidence after hip and knee surgery has been studied and documented, its incidence after surgery of the foot and ankle is unknown, For this reason, a prospective multicenter study was undertaken to identify patients with clinically evident thromboembolic disease to evaluate potential risk factors, Two thousand seven hundred thirty-three patients were evaluated for preoperative risk factors and postoperative thromboembolic events. There were six clinically significant thromboembolic events, including four nonfatal pulmonary emboli, after foot and ankle surgery. The incidence of deep vein thrombosis was six of 2733 (0.22%) and that of nonfatal pulmonary emboli was four of 2733 (0.15%). Factors found to correlate with an increased incidence of deep vein thrombosis were nonweightbearing status and immobilization after surgery, On the basis of these results, routine prophylaxis for thromboembolic disease after foot and ankle surgery probably is not warranted. C1 Boston Univ, Dept Orthopaed Surg, Boston, MA 02215 USA. Univ Virginia, Dept Orthopaed Surg, Charlottesville, VA USA. Univ Tennessee, Dept Orthopaed Surg, Chattanooga, TN USA. Univ Texas, Hlth Sci Ctr, Houston, TX USA. Univ So Calif, Los Angeles, CA USA. USN, Med Ctr, Dept Orthopaed, Portsmouth, VA USA. Univ Virginia, Sch Med, Dept Orthoped, Charlottesville, VA 22908 USA. Gillette Childrens Hosp, Dept Orthopaed Surg, Growth & Dev Ctr, St Paul, MN USA. Univ Washington, Seattle, WA 98195 USA. Univ Calif San Francisco, Sch Med, Dept Orthopaed Surg, Oakland, CA USA. Univ New Mexico Hosp, Dept Orthopaed Surg & Rehabil, Albuquerque, NM USA. Univ Tennessee, Coll Med, Staff Campbell Clin, Memphis, TN USA. Good Samaritan Hosp, Union Mem Hosp, Dept Orthopaed Surg, Baltimore, MD USA. Harvard Univ, Brigham & Womens Hosp, Sch Med, New England Baptist Hosp, Boston, MA 02115 USA. RP Mizel, MS (reprint author), Boston Med Ctr, 818 Harrison Ave,Dowling 2 N, Boston, MA 02118 USA. OI Michelson, James/0000-0001-6997-2666 NR 21 TC 56 Z9 56 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 MAR PY 1998 IS 348 BP 180 EP 185 PG 6 WC Orthopedics; Surgery SC Orthopedics; Surgery GA ZF333 UT WOS:000072887000028 PM 9553551 ER PT J AU Nowicki, MJ Peterson, RB AF Nowicki, MJ Peterson, RB TI Dubowitz syndrome and achalasia: Two rare conditions in a child SO CLINICAL PEDIATRICS LA English DT Article ID GLUCOCORTICOID DEFICIENCY; ESOPHAGEAL ACHALASIA; PNEUMATIC DILATATION; CARDIA; NIFEDIPINE; ESOPHAGOMYOTOMY; DISORDERS; PATIENT C1 USN, Med Ctr, Div Pediat, Portsmouth, VA 23708 USA. USN, Med Ctr, Div Adult Gastroenterol & Nutr, Portsmouth, VA 23708 USA. RP Nowicki, MJ (reprint author), USN, Med Ctr, Div Pediat Gastroenterol, Dept Pediat, 620 John Paul Jones Circle, Portsmouth, VA 23708 USA. NR 35 TC 3 Z9 3 U1 0 U2 0 PU WESTMINSTER PUBL INC PI GLEN HEAD PA 708 GLEN COVE AVE, GLEN HEAD, NY 11545 USA SN 0009-9228 J9 CLIN PEDIATR JI Clin. Pediatr. PD MAR PY 1998 VL 37 IS 3 BP 197 EP 200 DI 10.1177/000992289803700307 PG 4 WC Pediatrics SC Pediatrics GA ZC023 UT WOS:000072531800007 PM 9545609 ER PT J AU Todd, MD Vohra, ST AF Todd, MD Vohra, ST TI Transient dynamics of a lightly damped, roll-forced pendulum SO DYNAMICS AND STABILITY OF SYSTEMS LA English DT Article ID FRACTAL BASIN BOUNDARIES; SPHERICAL PENDULUM; CHAOS; MOTION AB A roll-forced pendulum is studied as a rudimentary model for a sea-state driven ship crane in this work. Centripetal acceleration measurements were made in a number of non-resonant forcing conditions. In addition to large-amplitude resonant responses, a variety of beating responses were found in the transient mode; this behavior is significant due to the light damping and thus long influence of the transient dynamics. The (transient as well as steady-state) frequency content of the centripetal acceleration spectrum is predicted and compared to experiment using power spectral methods and spectrograms. C1 USN, Res Lab, Washington, DC 20375 USA. RP Todd, MD (reprint author), USN, Res Lab, Code 5673,4555 Overlook Ave SW, Washington, DC 20375 USA. EM miketodd@ccf.nrl.navy.mil NR 19 TC 2 Z9 2 U1 0 U2 1 PU CARFAX PUBL CO PI ABINGDON PA PO BOX 25, ABINGDON, OXFORDSHIRE, ENGLAND OX14 3UE SN 0268-1110 J9 DYNAM STABIL SYST JI Dyn. Stab. Syst. PD MAR PY 1998 VL 13 IS 1 BP 95 EP 115 DI 10.1080/02681119808806255 PG 21 WC Mathematics, Applied; Mechanics SC Mathematics; Mechanics GA ZN873 UT WOS:000073692000004 ER PT J AU Lindler, KW Harper, MJ AF Lindler, KW Harper, MJ TI Combustor/emitter design tool for a thermophotovoltaic energy converter SO ENERGY CONVERSION AND MANAGEMENT LA English DT Article DE thermophotovoltaic; spreadsheet; energy conversion; combustion; thermal emitter AB Recently, there has been a renewed interest in thermophotovoltaic (TPV) energy conversion. A TPV device converts radiant energy from a high temperature incandescent emitter directly into electricity by photovoltaic cells. The current research at the U.S Naval Academy involves the design, construction and demonstration of a prototype TPV converter that uses a hydrocarbon fuel (such as natural gas) as the energy source. Since the photovoltaic cells are designed to convert radiant energy efficiently at a prescribed wavelength, it is important that the temperature of the emitter be nearly constant over its entire surface. The U.S Naval Academy is developing a small emitter (with a high emissivity) that can be maintained near 1478 K (2200F). This paper describes the computer spreadsheet model that was written as a tool to be used for the design of the high temperature emitter. Published by Elsevier Science Ltd. C1 USN Acad, Naval Architecture Ocean & Marine Dept, Annapolis, MD 21402 USA. RP Lindler, KW (reprint author), USN Acad, Naval Architecture Ocean & Marine Dept, 590 Holloway Rd, Annapolis, MD 21402 USA. NR 10 TC 4 Z9 4 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0196-8904 J9 ENERG CONVERS MANAGE JI Energy Conv. Manag. PD MAR-APR PY 1998 VL 39 IS 5-6 BP 391 EP 398 DI 10.1016/S0196-8904(97)00018-6 PG 8 WC Thermodynamics; Energy & Fuels; Mechanics SC Thermodynamics; Energy & Fuels; Mechanics GA YR390 UT WOS:000071483500004 ER PT J AU Wu, C Chen, LG Sun, FR AF Wu, C Chen, LG Sun, FR TI Optimization of steady flow heat pumps SO ENERGY CONVERSION AND MANAGEMENT LA English DT Article DE finite-time thermodynamics; heat pump; optimization ID MAXIMUM-POWER; FINITE-TIME; ENGINES; EFFICIENCY; LOAD AB The finite-time thermodynamic performance of steady flow Carnot and Brayton heat pump cycles has been studied for both finite and infinite thermal capacitance rates of heat reservoirs. The fundamental optimal relations of the two cycles are obtained. A comparison of the performance characteristics of the two cycles for the same boundary conditions (i.e. same heat source/sink inlet temperatures, thermal capacitance rates, and heat exchanger conductances) is shown. The effects of finite thermal capacitance rates of the working fluid and heat reservoirs and of the internal irreversibilities of the cycles on cycle performance are analyzed. Optimal matching between the temperatures of the working fluid and heat reservoirs is discussed. Published by Elsevier Science Ltd. C1 USN Acad, Dept Engn Mech, Annapolis, MD 21402 USA. USN, Acad Engn, Fac 306, Wuhan 430033, Peoples R China. RP Wu, C (reprint author), USN Acad, Dept Engn Mech, Annapolis, MD 21402 USA. NR 19 TC 45 Z9 47 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0196-8904 J9 ENERG CONVERS MANAGE JI Energy Conv. Manag. PD MAR-APR PY 1998 VL 39 IS 5-6 BP 445 EP 453 DI 10.1016/S0196-8904(97)00025-3 PG 9 WC Thermodynamics; Energy & Fuels; Mechanics SC Thermodynamics; Energy & Fuels; Mechanics GA YR390 UT WOS:000071483500010 ER PT J AU Morris, RE Hasan, MT Su, TCK Wechter, MA Turner, NH Schreifels, JA AF Morris, RE Hasan, MT Su, TCK Wechter, MA Turner, NH Schreifels, JA TI Significance of copper complex thermal stability in the use of metal deactivators at elevated temperatures SO ENERGY & FUELS LA English DT Article ID JET FUEL AB A series of compounds were examined to determine which structural aspects were necessary to effectively block the catalytic activity of soluble copper that promotes thermal deposition from jet fuel during JFTOT testing. The results indicated that salicylidene compounds such as that currently used as a metal-deactivating additive are the most effective, with the copper coordinated with both the nitrogen and oxygen atoms. The significance of the thermal stability of the copper complex of the metal-deactivator additive was revealed through thermal-desorption mass spectrometry and XPS examination of copper-rich JFTOT tube deposits generated at high temperatures. Through JFTOT testing with heater tubes constructed from a variety of alloys, the impact of alloy composition on thermal deposition from jet fuel was demonstrated. These findings were used to construct a hypothesis that is consistent with the appearance of MDA induction periods in accelerated turbulent flow fuel tests. C1 USN, Technol Ctr Safety & Survivabil, Res Lab, Washington, DC 20375 USA. USN, Surface Chem Branch, Res Lab, Washington, DC 20375 USA. Univ Massachusetts Dartmouth, Dept Chem, N Dartmouth, MA 02747 USA. George Mason Univ, Dept Chem, Fairfax, VA 22030 USA. RP Morris, RE (reprint author), USN, Technol Ctr Safety & Survivabil, Res Lab, Code 6181, Washington, DC 20375 USA. EM morris4@ccf.nrl.navy.mil NR 29 TC 5 Z9 5 U1 2 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0887-0624 J9 ENERG FUEL JI Energy Fuels PD MAR-APR PY 1998 VL 12 IS 2 BP 371 EP 378 DI 10.1021/ef970143f PG 8 WC Energy & Fuels; Engineering, Chemical SC Energy & Fuels; Engineering GA ZD102 UT WOS:000072651600027 ER PT J AU Yashiro, Y Tai, XG Toyo-oka, K Park, CS Abe, R Hamaoka, T Kobayashi, M Neben, S Fujiwara, H AF Yashiro, Y Tai, XG Toyo-oka, K Park, CS Abe, R Hamaoka, T Kobayashi, M Neben, S Fujiwara, H TI A fundamental difference in the capacity to induce proliferation of naive T cells between CD28 and other co-stimulatory molecules SO EUROPEAN JOURNAL OF IMMUNOLOGY LA English DT Article DE co-stimulation; CD28; T cell proliferation; IL-2 ID MONOCLONAL-ANTIBODIES; CD28-DEFICIENT MICE; INDUCED APOPTOSIS; RECEPTOR; ACTIVATION; ANTIGEN; COSTIMULATION; RESPONSES; EXPRESSION; SURVIVAL AB T cell activation requires two signals: a signal from the TCR and a co-stimulatory signal provided by antigen-presenting cells (APC). In addition to CD28, multiple molecules on the T cell have been described to deliver cc-stimulatory signals. Here, we investigated whether there exist quantitative or qualitative differences in the co-stimulatory capacity between CD28 and other molecules. Anti-CD28 monoclonal antibody (mAb) and mAb against CD5, CD9, CD2, CD44 or CD11a all induced activation of naive T cells in the absence of APC when coimmobilized with a submitogenic dose of anti-CD3 mAb. [H-3]Thymidine incorporation determined 2 days after cc-stimulation was all comparable. In contrast to progressive T cell proliferation induced by CD28 co-stimulation, cc-stimulation by other T cell molecules led to a decrease in viable cell recovery along with the induction of apoptosis of once activated T cells. This was associated with a striking difference in IL-2 production; CD28 co-stimulation induced progressively increasing IL-2 production, whereas cc-stimulation by other molecules produced limited amounts of IL-2. Addition of recombinant IL-2 to the latter cultures corrected the induction of apoptosis, resulting in levels of cellular proliferation comparable to those observed for CD28 co-stimulation. These results indicate that a fundamental difference exists in the nature of co-stimulation between CD28 and other molecules, which can be evaluated by the levels of IL-2 production, but not simply by [H-3]thymidine incorporation. C1 Osaka Univ, Sch Med, Biomed Res Ctr, Suita, Osaka 565, Japan. Sci Univ Tokyo, Res Inst Biol Sci, Chiba, Japan. USN, Med Res Inst, Immune Cell Biol Program, Bethesda, MD USA. Genet Inst, Cambridge, MA USA. RP Fujiwara, H (reprint author), Osaka Univ, Sch Med, Biomed Res Ctr, 2-2 Yamadaoka, Suita, Osaka 565, Japan. NR 42 TC 45 Z9 46 U1 0 U2 0 PU WILEY-V C H VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 0014-2980 J9 EUR J IMMUNOL JI Eur. J. Immunol. PD MAR PY 1998 VL 28 IS 3 BP 926 EP 935 DI 10.1002/(SICI)1521-4141(199803)28:03<926::AID-IMMU926>3.0.CO;2-0 PG 10 WC Immunology SC Immunology GA ZD715 UT WOS:000072716200019 PM 9541588 ER PT J AU Kirshenbaum, AS Worobec, AS Davis, TA Goff, JP Semere, T Metcalfe, DD AF Kirshenbaum, AS Worobec, AS Davis, TA Goff, JP Semere, T Metcalfe, DD TI Inhibition of human mast cell growth and differentiation by interferon gamma-1b SO EXPERIMENTAL HEMATOLOGY LA English DT Article DE IFN gamma-1b; IFN alpha-2b; mast cells; Fc(epsilon)RI ID MARROW PROGENITOR CELLS; BLOOD MONONUCLEAR-CELLS; BONE-MARROW; PERIPHERAL-BLOOD; C-KIT; MASTOCYTOSIS; MUTATION; DISEASES; LEUKEMIA AB In an effort to identify cytokines that inhibit human mast cell growth, we cultured HMC-1 cells and recombinant human stem cell factor (rhSCF)-dependent human bone marrow-derived mast cells (HBMCs) in the presence of interferon gamma (IFN gamma)-1b and interferon alpha (IFN alpha)-2b. HMC-1 cell numbers decreased in the presence of 1000 U/mL IFN gamma-1b but were unaffected by 1000 UlmL of IFN alpha-2b. HBMCs were then cultured for 0 to 7 days with 100 ng/mL rhSCF and 10 ng/mL recombinant human IL-3 (rhIL-3), followed by culture in rhSCF and administration of either 1000 U/mL IFN alpha-2b or 1000 U/mL IFN gamma-1b. HBMCs appearing in cultures with rhSCF alone or in combination with IFN alpha-2b were virtually identical in number through 8 weeks of culture. In cultures supplemented with IFN gamma-1b, HBMCs significantly decreased in number and incidence of granular metachromasia by 4 to 5 weeks (p < 0.001). Similar results were obtained when human marrow was cultured from day 0 with rhSCF and IFN gamma-1b. Mature rhSCF-dependent HBMCs were also cultured at 5 weeks with rhSCF alone or in combination with IFN gamma-1b. Compared with cells cultured in rhSCF, mature 5-week HBMC cultures treated with rhSCF plus IFN gamma-1b revealed a decrease in mast cells, and those mast cells that remained had fewer toluidine blue- and tryptase-positive granules after 5 to 8 weeks. FACS analysis of rhSCF plus IFN gamma-1b-treated mature HBMCs revealed increased c-kit and Fc(epsilon)RI expression. Mast cell releasibility was not increased. IFN gamma-1b was thus able to suppress mast cell growth from CD34(+) cells, suggesting that this agent should be considered as a candidate cytokine for the treatment of disorders of mast cell proliferation. C1 NIAID, Lab Allerg Dis, NIH, Bethesda, MD 20892 USA. USN, Med Res Inst, Immune Cell Biol Program, Stem Cell Biol Branch, Bethesda, MD USA. Univ Pittsburgh, Med Ctr, Dept Radiat Oncol, Pittsburgh, PA USA. RP Kirshenbaum, AS (reprint author), NIAID, Lab Allerg Dis, NIH, Bldg 10,Room 11C 208,10 Ctr Dr MSC 1881, Bethesda, MD 20892 USA. NR 28 TC 40 Z9 40 U1 0 U2 2 PU CARDEN JENNINGS PUBL CO LTD PI CHARLOTTESVILLE PA BLAKE CTR, STE 200, 1224 W MAIN ST, CHARLOTTESVILLE, VA 22903 USA SN 0301-472X J9 EXP HEMATOL JI Exp. Hematol. PD MAR PY 1998 VL 26 IS 3 BP 245 EP 251 PG 7 WC Hematology; Medicine, Research & Experimental SC Hematology; Research & Experimental Medicine GA YZ911 UT WOS:000072306900010 PM 9502621 ER PT J AU Slowey, MJ Coddington, CC AF Slowey, MJ Coddington, CC TI Microsurgical tubal anastomoses performed as an outpatient procedure by minilaparotomy are less expensive and as safe as those performed as an inpatient procedure SO FERTILITY AND STERILITY LA English DT Article DE cost analysis; outpatient surgery; sterilization reversal; tubal anastomoses; tubal reanastomoses ID STERILIZATION REVERSAL; LAPAROSCOPY AB Objective: To determine the cost-effectiveness, safety, and success of microsurgical tubal anastomoses performed by minilaparotomy as an outpatient. Design: Retrospective. Setting: Military tertiary care medical center. Patient(s): Seventy consecutively seen a omen of reproductive age who were undergoing surgical reversal of sterilization from August 1, 1993, through August 1, 1995. Intervention(s): Microsurgical sterilization reversal by minilaparotomy was performed as an inpatient (group 1, 47 patients) or as an outpatient (group 2, 23 patients), Main Outcome Measure(s): Cost, complication rate, pregnancy rate. Result(s): The procedure cost more for inpatients ($3,116) than for outpatients ($1,456). Pregnancy rates were similar (56% in group 1 vs. 75% in group 2). There was only one complication in the series. Conclusion(s): Outpatient microsurgical sterilization reversal performed by minilaparotomy is as safe and effective as the inpatient procedure and is less expensive. (C) 1998 by American Society for Reproductive Medicine. C1 USN, Med Ctr, Dept Obstet & Gynecol, Portsmouth, VA USA. Eastern Virginia Med Sch, Jones Inst Reprod Med, Dept Obstet & Gynecol, Norfolk, VA USA. RP Slowey, MJ (reprint author), NE Med Ctr, Fertil Ctr, 1521 Newgate Court, Concord, NC 28027 USA. NR 14 TC 11 Z9 13 U1 0 U2 1 PU AMER SOC REPRODUCTIVE MEDICINE PI BIRMINGHAM PA 1209 MONTGOMERY HIGHWAY, BIRMINGHAM, AL 35216-2809 USA SN 0015-0282 J9 FERTIL STERIL JI Fertil. Steril. PD MAR PY 1998 VL 69 IS 3 BP 492 EP 495 DI 10.1016/S0015-0282(97)00549-9 PG 4 WC Obstetrics & Gynecology; Reproductive Biology SC Obstetrics & Gynecology; Reproductive Biology GA ZD012 UT WOS:000072642000024 PM 9531884 ER PT J AU Lein, AY Vogt, P Crane, K Egorov, AV Pimenov, NV Savichev, AS Ginsburg, GD Ivanov, GI Cherkashev, GA Ivanov, MV AF Lein, AY Vogt, P Crane, K Egorov, AV Pimenov, NV Savichev, AS Ginsburg, GD Ivanov, GI Cherkashev, GA Ivanov, MV TI Geochemical features of gas-bearing (CH4) deposits of a submarine mud volcano in the Norwegian sea SO GEOKHIMIYA LA Russian DT Article ID METHANE; BIOGEOCHEMISTRY C1 VI Vernadskii Inst Geochem & Analyt Chem, Moscow 117975, Russia. USN, Res Lab, Marine Geosci Div, Washington, DC 20375 USA. CUNY Hunter Coll, New York, NY 10021 USA. PP Shirshov Oceanol Inst, Moscow 117218, Russia. Russian Acad Sci, Inst Microbiol, Moscow 117811, Russia. All Russian Oceanol Geol Res Inst, St Petersburg 190121, Russia. RP Lein, AY (reprint author), VI Vernadskii Inst Geochem & Analyt Chem, Ul Kosygina 19, Moscow 117975, Russia. RI Cherkashov, Georgy/N-6949-2013 OI Cherkashov, Georgy/0000-0002-9870-6428 NR 36 TC 9 Z9 12 U1 0 U2 0 PU ROSSIISKAYA AKADEMIYA NAUK PI MOSCOW PA SAVELEVSKII PER., 13 OCTOZHENKA, 119034 MOSCOW, RUSSIA SN 0016-7525 J9 GEOKHIMIYA+ JI Geokhimiya PD MAR PY 1998 IS 3 BP 230 EP 249 PG 20 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA ZJ974 UT WOS:000073272400002 ER PT J AU Henry, KS Patton, S AF Henry, KS Patton, S TI Measurement of the contact angle of water on geotextile fibers SO GEOTECHNICAL TESTING JOURNAL LA English DT Article DE geotextile; capillary barrier; contact angle; wetting; fiber AB The contact angle of water on geotextile fibers significantly influences capillary behavior. Measurements of the dynamic contact angle of tap water on geotextile fibers are reported for two geotextiles, as received from the manufacturer and after they had been treated (cleaned). There is considerable hysteresis between advancing and receding contact angles, as expected. Fibers from one geotextile have significantly lower contact angle cosines than the other, indicating that it is less wettable. The cleaning of geotextiles resulted in significant reduction in the advancing contact angles of fibers from one of the geotextiles but not the other. The heights of water capillary rise in strips of the geotextiles were also measured. Results showed that the contact angle measurements are helpful; but, information on pore sizes is also needed to predict capillary behavior. C1 USA, Cold Reg Res & Engn Lab, Hanover, NH 03755 USA. USN, Undersea Warfare Ctr, Environm Div, Newport, RI 02844 USA. RP Henry, KS (reprint author), USA, Cold Reg Res & Engn Lab, 72 Lyme Rd, Hanover, NH 03755 USA. NR 16 TC 12 Z9 12 U1 0 U2 0 PU AMER SOC TESTING MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DR, W CONSHOHOCKEN, PA 19428-2959 USA SN 0149-6115 J9 GEOTECH TEST J JI Geotech. Test. J. PD MAR PY 1998 VL 21 IS 1 BP 11 EP 17 PG 7 WC Engineering, Geological; Geosciences, Multidisciplinary SC Engineering; Geology GA YY809 UT WOS:000072187600002 ER PT J AU Overfelt, PL AF Overfelt, PL TI Electric lines of force of an electrically small dipole-loop antenna array SO IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION LA English DT Article DE antenna arrays ID EFFICIENCIES AB The electric Lines of force of an electrically small dipole-loop antenna array have been determined analytically for both the near- and far-fields of the array. It has been found that the behavior of the families of electric contours are dependent upon a coupling parameter, which is the ratio of the loop and dipole sizes and currents. This parameter also controls the appearance (or not) and position of the points of equilibrium for the radiated field when analyzed in a real phase plane. The electric lines of force of the dipole-loop array exhibit increased directivity in the plane of the array when the coupling parameter is purely real, indicating that the respective dipole and loop currents must be in phase quadrature for this effect to occur. C1 USN, Ctr Air Warfare, Weap Div, Res & Technol Grp, China Lake, CA 93555 USA. RP Overfelt, PL (reprint author), USN, Ctr Air Warfare, Weap Div, Res & Technol Grp, China Lake, CA 93555 USA. NR 24 TC 6 Z9 6 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 MAR PY 1998 VL 46 IS 3 BP 451 EP 456 DI 10.1109/8.662665 PG 6 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA ZB692 UT WOS:000072498000019 ER PT J AU Sudhoff, SD Corzine, KA Glover, SF Hegner, HJ Robey, HN AF Sudhoff, SD Corzine, KA Glover, SF Hegner, HJ Robey, HN TI DC link stabilized field oriented control of electric propulsion systems SO IEEE TRANSACTIONS ON ENERGY CONVERSION LA English DT Article AB Induction motor based electric propulsion systems can be used in a wide variety of applications including locomotives, hybrid electric vehicles, and ships. Field oriented control of these drives is attractive since it allows the torque to be tightly and nearly instantaneously controlled. However, such systems can be prone to negative impedance instability of the de link. This paper examines this type of instability and sets forth a readily implemented albeit nonlinear control strategy to mitigate this potential problem. C1 Univ Missouri, Dept Elect Engn, Rolla, MO 65401 USA. USN, Ctr Surface Warfare, Annapolis Detachment, Carderock Div, Annapolis, MD 21402 USA. RP Sudhoff, SD (reprint author), Univ Missouri, Dept Elect Engn, Rolla, MO 65401 USA. NR 8 TC 72 Z9 74 U1 1 U2 8 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0885-8969 J9 IEEE T ENERGY CONVER JI IEEE Trans. Energy Convers. PD MAR PY 1998 VL 13 IS 1 BP 27 EP 33 DI 10.1109/60.658200 PG 7 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA YY930 UT WOS:000072202200005 ER PT J AU Pekarek, SD Wasynczuk, O Hegner, HJ AF Pekarek, SD Wasynczuk, O Hegner, HJ TI An efficient and accurate model for the simulation and analysis of synchronous machine/converter systems SO IEEE TRANSACTIONS ON ENERGY CONVERSION LA English DT Article ID LINE-COMMUTATED CONVERTER; MACHINE SYSTEMS AB A new synchronous machine model is presented which is readily implemented in either circuit-based or differential-equation-based simulation programs. This model is well suited for the simulation and analysis of synchronous machine - converter systems, It is based upon standard representations and no approximations are made in its derivation, However, the numerical implementation is shown to be significantly more efficient. An example is provided which demonstrates a 1700% increase in simulation speed with no observable loss in accuracy. The model includes provisions for an arbitrary number of damper or rotor windings and may be easily modified to represent synchronous or induction machines with an arbitrary number of stator phases. C1 Purdue Univ, Sch Elect & Comp Engn, W Lafayette, IN 47907 USA. USN, Ctr Surface Warfare, Annapolis, MD USA. RP Pekarek, SD (reprint author), Purdue Univ, Sch Elect & Comp Engn, W Lafayette, IN 47907 USA. NR 10 TC 63 Z9 63 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 0885-8969 J9 IEEE T ENERGY CONVER JI IEEE Trans. Energy Convers. PD MAR PY 1998 VL 13 IS 1 BP 42 EP 48 DI 10.1109/60.658202 PG 7 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA YY930 UT WOS:000072202200007 ER PT J AU Fetterer, F Gineris, D Wackerman, CC AF Fetterer, F Gineris, D Wackerman, CC TI Validating a scatterometer wind algorithm for ERS-1 SAR SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article DE image analysis; radar applications; satellite applications; synthetic aperture radar (SAR); wind ID SYNTHETIC-APERTURE RADAR; IMAGERY; SATELLITE AB The ocean surface wind field is observed from space operationally using scatterometry. The European Space Agency's (ESA's) ERS-1 satellite scatterometer routinely produces a wind product that is assimilated into forecast models, Scatterometry cannot give accurate wind estimates close to land, however, because the field of view of a spaceborne scatterometer is on the order of 50 km, Side lobe contamination, due to the large contrast in backscatter between land and water, compounds the problem, Synthetic aperture radar (SAR) can provide wind speed and direction estimates on a finer scale, so that high-resolution wind fields can be constructed near shore, An algorithm has been developed that uses the spectral expression of wind in SAR imagery to estimate wind direction and calibrated backscatter to estimate wind strength, Three versions, based on C-band scatterometer algorithms, are evaluated here for accuracy in potential operational use, Algorithm estimates are compared with wind measurements from buoys in the Gulf of Alaska, Bering Strait, and off the Pacific Northwest coast by using a data set of 61 near-coincident buoy and ERS-1 SAR observations, Representative figures for the accuracy of the algorithm are +/-2 m/s for wind speed and +/-37 degrees for wind direction at a 25-km spatial resolution. C1 USN, Res Lab, Remote Sensing Applicat Branch, Environm Res Inst Michigan Off, Stennis Space Ctr, MS 39529 USA. Environm Res Inst Michigan, Ctr Earth Sci, Ann Arbor, MI 48113 USA. RP Fetterer, F (reprint author), Univ Colorado, CIRES, Natl Snow & Ice Data Ctr, Boulder, CO 80309 USA. EM fetterer@kryos.colorado.edu NR 20 TC 57 Z9 63 U1 2 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0196-2892 J9 IEEE T GEOSCI REMOTE JI IEEE Trans. Geosci. Remote Sensing PD MAR PY 1998 VL 36 IS 2 BP 479 EP 492 DI 10.1109/36.662731 PG 14 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA ZC333 UT WOS:000072566800010 ER PT J AU Ashton, EA AF Ashton, EA TI Detection of subpixel anomalies in multispectral infrared imagery using an adaptive Bayesian classifier SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article DE classification; multispectral; segmentation; subpixel; target detection ID TEXTURED IMAGES; SEGMENTATION; ALGORITHM; DESIGN AB The detection of subpixel targets with unknown spectral signatures and cluttered backgrounds in multispectral imagery is a topic of great interest for remote surveillance applications, Because no knowledge of the target is assumed, the only way to accomplish such a detection Is through a search for anomalous pixels. Two approaches to this problem are examined in this paper, The first is to separate the image into a number of statistical clusters by using an extension of the well-known k-means algorithm, Each bin of resultant residual vectors is then decorrelated, and the results are thresholded to provide detection, The second approach requires the formation of a probabilistic background model by using an adaptive Bayesian classification algorithm, This allows the calculation of a probability for each pixel, with respect to the model, These probabilities are then thresholded to provide detection, Both algorithms are shown to provide significant improvement over current filtering techniques for anomaly detection in experiments using multispectral IR imagery with both simulated and actual subpixel targets. C1 USN, Res Lab, Washington, DC 20375 USA. RP Ashton, EA (reprint author), USN, Res Lab, Code 5621, Washington, DC 20375 USA. NR 20 TC 63 Z9 65 U1 0 U2 7 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0196-2892 J9 IEEE T GEOSCI REMOTE JI IEEE Trans. Geosci. Remote Sensing PD MAR PY 1998 VL 36 IS 2 BP 506 EP 517 DI 10.1109/36.662733 PG 12 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA ZC333 UT WOS:000072566800012 ER PT J AU Biblarz, O Bell, WJ AF Biblarz, O Bell, WJ TI Thermionic arc breakdown in small discharge gaps: Model and applications SO IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS LA English DT Article; Proceedings Paper CT Annual Meeting of Industry-Applications-Society CY OCT 06-10, 1996 CL SAN DIEGO, CALIFORNIA SP Ind Applicat Soc DE incandescent arc ignition; ionization chambers; low-voltage discharges ID PLASMAS AB A model for thermionically induced breakdown is developed which predicts the voltage levels experienced in low-voltage discharges, Initially, electron emission across an active discharge minigap must be established, Prior to breakdown, emitted electrons populate the cathode space-charge region and the remaining gap is un-ionized. Breakdown criteria and a means for estimating the reduced breakdown voltage in the bulk gas are derived in terms of conventional Townsend ionization mechanisms, wherein multistep or cumulative ionization must be active. Since the cathode space-charge region is replete with emitted electrons, positive ions traversing it release to the bulk gas considerably more electrons than would be available with the conventional Townsend gamma mechanism at the cathode surface, This equivalently higher gamma significantly shifts the Paschen curve toward lower minima. One practical thermionic assisting device is a tungsten light-bulb-grade filament, which shunts the primary discharge electrodes and within the filament's minigaps breakdown occurs, Thermionic are breakdown has been implemented in the starting of are devices for lamps and in thermionic power converters; an application to ionization chambers in electrostatic thrusters is also discussed. C1 USN, Postgrad Sch, Monterey, CA 93943 USA. RP Biblarz, O (reprint author), USN, Postgrad Sch, Monterey, CA 93943 USA. NR 36 TC 2 Z9 2 U1 1 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0093-9994 J9 IEEE T IND APPL JI IEEE Trans. Ind. Appl. PD MAR-APR PY 1998 VL 34 IS 2 BP 325 EP 331 DI 10.1109/28.663475 PG 7 WC Engineering, Multidisciplinary; Engineering, Electrical & Electronic SC Engineering GA ZD221 UT WOS:000072663500012 ER PT J AU Amano, KI Williams, JC Dasch, GA AF Amano, KI Williams, JC Dasch, GA TI Structural properties of lipopolysaccharides from Rickettsia typhi and Rickettsia prowazekii and their chemical similarity to the lipopolysaccharide from Proteus vulgaris OX19 used in the Weil-Felix test SO INFECTION AND IMMUNITY LA English DT Article ID PHASE-I; COXIELLA-BURNETII; TEST ANTIGENS; IMMUNOLOGICAL CHARACTERIZATION; TSUTSUGAMUSHI; PEPTIDOGLYCAN; REACTIVITY; COMPONENTS; SERA AB The lipopolysaccharides (LPSs) isolated from typhus group (TG) rickettsiae Rickettsia typhi and Rickettsia prowazekii were characterized by chemical analysis and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) followed by silver staining. LPSs from two species of TG rickettsiae contained glucose, 3-deoxy-D-manno-octulosonic acid, glucosamine, quinovosamine, phosphate, and fatty acids (beta-hydroxylmyristic acid and heneicosanoic acid) but not heptose. The O-polysaccharides of these LPSs were composed of glucose, glucosamine, quinovosamine, and phosphorylated hexosamine. Resolution of these LPSs by their apparent molecular masses by SDS-PAGE showed that they have a common ladder-like pattern. Based on the results of chemical composition and SDS-PAGE pattern, we suggest that these LPSs act as group-specific antigens. Furthermore, glucosamine, quinovosamine, and phosphorylated hexosamine were also found in the O-polysaccharide of the LPS from Proteus vulgaris OX19 used in the Weil-Felix test, suggesting that they may represent the antigens common to LPSs from TG rickettsiae and P. vulgaris OX19. C1 USA, Med Res Inst Infect Dis, Rickettsial Dis Lab, Airborne Dis Div, Frederick, MD 21701 USA. NIAID, Off Sci Director, Bethesda, MD 20204 USA. USN, Med Res Inst, Bethesda, MD 20014 USA. RP Amano, KI (reprint author), Akita Univ, Sch Med, Cent Res Lab, Hondo 1-1-1, Akita 010, Japan. EM amanocrl@med.akita-u.ac.jp NR 34 TC 16 Z9 16 U1 0 U2 4 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 USA SN 0019-9567 J9 INFECT IMMUN JI Infect. Immun. PD MAR PY 1998 VL 66 IS 3 BP 923 EP 926 PG 4 WC Immunology; Infectious Diseases SC Immunology; Infectious Diseases GA YY565 UT WOS:000072160900006 PM 9488376 ER PT J AU Pei, ZH Burucoa, C Grignon, B Baqar, S Huang, XZ Kopecko, DJ Bourgeois, AL Fauchere, JL Blaser, MJ AF Pei, ZH Burucoa, C Grignon, B Baqar, S Huang, XZ Kopecko, DJ Bourgeois, AL Fauchere, JL Blaser, MJ TI Mutation in the peb1A locus of Campylobacter jejuni reduces interactions with epithelial cells and intestinal colonization of mice SO INFECTION AND IMMUNITY LA English DT Article ID ESCHERICHIA-COLI; GEL-ELECTROPHORESIS; NUCLEOTIDE-SEQUENCE; POLYACRYLAMIDE GELS; HELA-CELLS; PROTEINS; IDENTIFICATION; ENTERITIS; MEMBRANE; PATHOGENESIS AB Campylobacter jejuni is one of the leading causes of bacterial diarrhea throughout the world. We previously found that PERI is a homolog of cluster 3 binding proteins of bacterial ABC transporters and that a C. jejuni adhesin, cell-binding factor 1 (CBF1), if not identical to, contains PEB1. A single protein migrating at approximately 27 to 28 kDa was recognized by anti-CBF1 and anti-PEB1. To determine the role that the operon encoding PEB1 plays in C. jejuni adherence, peb1A, the gene encoding PEB1, was disrupted in strain 81-176 by insertion of a kanamycin resistance gene through homologous recombination. Inactivation of this operon completely abolished expression of CBF1, as determined by sodium dodecyl sulfate-polyaccrylamide gel electrophoresis (SDS-PAGE) and immunoblotting. In comparison to the wild-type strain, the mutant strain showed 50- to 100-fold less adherence to and 15-fold less invasion of epithelial cells in culture, Mouse challenge studies showed that the rate and duration of intestinal colonization by the mutant were significantly lower and shorter than with the wild-type strain. In summary, PEB1 is identical to a previously identified cell-binding factor, CBF1, in C. jejuni, and the peb1A locus plays an important role in epithelial cell interactions and in intestinal colonization in a mouse model. C1 Vanderbilt Univ, Sch Med, Div Infect Dis, Dept Med, Nashville, TN 37232 USA. Vanderbilt Univ, Sch Med, Dept Microbiol & Immunol, Nashville, TN 37232 USA. Vet Affairs Med Ctr, Nashville, TN 37212 USA. CHU La Miletrie, Lab Microbiol A, F-86021 Poitiers, France. USN, Med Res Inst, Enter Dis Program, Bethesda, MD USA. US FDA, Lab Enter & Sexually Transmitted Dis, CBER, Rockville, MD 20857 USA. RP Blaser, MJ (reprint author), Vanderbilt Univ, Sch Med, Div Infect Dis, Dept Med, A-3310 Med Ctr N, Nashville, TN 37232 USA. NR 43 TC 122 Z9 135 U1 0 U2 4 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 USA SN 0019-9567 J9 INFECT IMMUN JI Infect. Immun. PD MAR PY 1998 VL 66 IS 3 BP 938 EP 943 PG 6 WC Immunology; Infectious Diseases SC Immunology; Infectious Diseases GA YY565 UT WOS:000072160900009 PM 9488379 ER PT J AU Georgiou, IT Bajaj, AK Corless, M AF Georgiou, IT Bajaj, AK Corless, M TI Invariant manifolds and chaotic vibrations in singularly perturbed nonlinear oscillators SO INTERNATIONAL JOURNAL OF ENGINEERING SCIENCE LA English DT Article AB This work concerns the forced nonlinear vibrations of a dissipative soft-stiff structural dynamical system consisting of a soft nonlinear oscillator coupled to a linear stiff oscillator. The equations of motion are cast into a set of singularly perturbed ordinary differential equations, with the ratio of linear frequency like quantities as the singular parameter. Then, using the theory of invariant manifolds, it is shown that, for sufficiently small coupling, the forced system possesses a 3-dimensional slow invariant manifold. The invariant manifold is a regular perturbation of a global invariant manifold for the conservative system. It is shown that the conservative system possesses a homoclinic orbit on the slow invariant manifold. Numerical simulations reveal that the forced system undergoes a period doubling cascade of bifurcations. The cascade of bifurcations gives rise to a weak strange attractor which. undergoes a metamorphosis into a strong strange attractor as the forcing amplitude increases, Using Melnikov's method, it is shown that the strong strange attractor stems from transverse intersections of the invariant manifolds of a saddle-type periodic motion carried by the slow invariant manifold. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 USN, Res Lab, Washington, DC 20375 USA. Purdue Univ, Sch Mech Engn, W Lafayette, IN 47907 USA. Purdue Univ, Sch Aeronaut & Astronaut, W Lafayette, IN 47907 USA. RP Georgiou, IT (reprint author), USN, Res Lab, Code 6700-3, Washington, DC 20375 USA. RI Corless, Martin/F-2299-2011 NR 18 TC 7 Z9 7 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0020-7225 J9 INT J ENG SCI JI Int. J. Eng. Sci. PD MAR PY 1998 VL 36 IS 4 BP 431 EP 458 DI 10.1016/S0020-7225(97)00078-5 PG 28 WC Engineering, Multidisciplinary SC Engineering GA ZM309 UT WOS:000073525600006 ER PT J AU Cipolla, KM Rockwell, D AF Cipolla, KM Rockwell, D TI Instantaneous crossflow topology on a delta wing in presence of vortex breakdown SO JOURNAL OF AIRCRAFT LA English DT Article AB The crossflow structure of the leading-edge vortices on a delta wing is investigated via particle image velocimetry. The transformation of the streamline topology as the vortex breakdown position moves up- or downstream of its nominal value is characterized by comparing instantaneous images. While the streamline patterns are distinctly different depending on the location of vortex breakdown relative to the field of view, contours of constant vorticity do not exhibit such distinctions. Several classes of instantaneous streamline topology can exist in the crossflow plane. These topologies, which involve various combinations of limit cycles and foci, indicate the importance of considering the instantaneous nature of both the vorticity contours and streamlines when describing the flow physics. C1 Lehigh Univ, Dept Engn Mech, Bethlehem, PA 18015 USA. RP Cipolla, KM (reprint author), USN, Ctr Undersea Warfare, Newport, RI 02840 USA. NR 18 TC 4 Z9 6 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 218 EP 223 DI 10.2514/2.2311 PG 6 WC Engineering, Aerospace SC Engineering GA ZE540 UT WOS:000072803600008 ER PT J AU Kelso, JM AF Kelso, JM TI RANTES SO JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY LA English DT Letter C1 USN, Med Ctr, San Diego, CA 92134 USA. RP Kelso, JM (reprint author), USN, Med Ctr, San Diego, CA 92134 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 0091-6749 J9 J ALLERGY CLIN IMMUN JI J. Allergy Clin. Immunol. PD MAR PY 1998 VL 101 IS 3 BP 432 EP 432 PG 1 WC Allergy; Immunology SC Allergy; Immunology GA ZC570 UT WOS:000072593900030 PM 9525469 ER PT J AU Bewley, WW Vurgaftman, I Felix, CL Meyer, JR Lin, CH Zhang, D Murry, SJ Pei, SS Ram-Mohan, LR AF Bewley, WW Vurgaftman, I Felix, CL Meyer, JR Lin, CH Zhang, D Murry, SJ Pei, SS Ram-Mohan, LR TI Role of internal loss in limiting type-II mid-IR laser performance SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID QUANTUM-WELL LASERS; SEMICONDUCTOR-LASERS; AUGER LIFETIME; SUPERLATTICES; TEMPERATURE; ABSORPTION; TRANSITION; INAS; GAIN AB We report an experimental and theoretical investigation of internal losses in optically pumped type-II lasers with InAs/GaSb/Ga1-xInxSb/GaSb superlattice active regions. Whereas the losses are found to be moderate at 100 K (11-14 cm(-1)), they increase rapidly with increasing temperature (to 50-120 cm(-1) at 200 K). Comparison with a detailed numerical simulation shows that the internal losses play a much more important role than Auger recombination or carrier/lattice heating in limiting the laser performance at high temperatures. Calculations of the temperature-dependent intervalence absorption cross sections show that losses of the magnitude observed experimentally can easily occur if one does not take special care to avoid resonances in all regions of the Brillouin zone. Practical design guidelines are presented. The superlattice lasers yield maximum peak output powers of up to 6.5 W per facet at 100 K and 3.5 W per facet at 180 K, threshold incident pump intensities as low as 340 W/cm(2) at 100 K, and Shockley-Read lifetimes >30 ns at 100 K. The Auger coefficients are suppressed (less than or equal to 1.6x10(-27) cm(6)/s at T=260 K) despite the intervalence resonances which produce the high internal losses. (C) 1998 American Institute of Physics. C1 USN, Res Lab, Washington, DC 20375 USA. Univ Houston, Ctr Space Vacuum Epitaxy, Houston, TX 77204 USA. Worcester Polytech Inst, Worcester, MA 01609 USA. RP Bewley, WW (reprint author), USN, Res Lab, Code 5613, Washington, DC 20375 USA. EM meyer@sisyphus.nrl.navy.mil RI Ram-Mohan, Ramdas/C-5167-2012 NR 29 TC 55 Z9 55 U1 1 U2 5 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 2384 EP 2391 DI 10.1063/1.366997 PG 8 WC Physics, Applied SC Physics GA YZ942 UT WOS:000072310700002 ER PT J AU Sprunt, S Geer, RE Crawford, GP Naciri, J Ratna, BR Shashidhar, R AF Sprunt, S Geer, RE Crawford, GP Naciri, J Ratna, BR Shashidhar, R TI Large second-order optical nonlinearity in a molecular crystal formed from a chiral smectic liquid crystal SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID 2ND-HARMONIC GENERATION AB A new approach to achieving a large second-order nonlinear optical susceptibility in a chiral liquid crystal is described. This approach uses an aligned smectic-C* liquid crystal as a template for forming a molecular crystal, which freezes out the rotation of the molecular dipoles and thereby greatly enhances the noncentrosymmetric order of the structure. Analysis of the measured second harmonic generation gives maximum values of individual susceptibility components of similar to 25 pm/V, which are stable when the held is removed. (C) 1998 American Institute of Physics. C1 Kent State Univ, Dept Phys, Kent, OH 44242 USA. SUNY Albany, Dept Phys, Albany, NY 12222 USA. Brown Univ, Div Engn, Providence, RI 02912 USA. USN, Res Lab, Ctr Biomol Sci & Engn, Washington, DC 20375 USA. RP Sprunt, S (reprint author), Kent State Univ, Dept Phys, Kent, OH 44242 USA. NR 14 TC 1 Z9 1 U1 0 U2 0 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 2392 EP 2398 DI 10.1063/1.366998 PG 7 WC Physics, Applied SC Physics GA YZ942 UT WOS:000072310700003 ER PT J AU Grun, J Burris, R Joyce, G Slinker, S Huba, J Evans, K Manka, CK Barthel, JR Wiehe, JW AF Grun, J Burris, R Joyce, G Slinker, S Huba, J Evans, K Manka, CK Barthel, JR Wiehe, JW TI Small-scale laboratory measurement and simulation of a thermal precursor shock SO JOURNAL OF APPLIED PHYSICS LA English DT Article AB A shock precursor in a thin thermal layer above a 3000 K hot surface is measured in a small-scale laboratory experiment. Precursor and thermal layer characteristics are diagnosed using spectroscopy, interferometry, and dark-field shadowgraphy. The experiment is successfully simulated with a code previously validated using large-scale high-explosive tests, thereby demonstrating its applicability to events that differ in energy by 12 orders of magnitude. The simulation shows that a small-scale laboratory experiment can be a good surrogate for infrequent, expensive, and hard to diagnose large-scale tests. (C) 1998 American Institute of Physics. C1 USN, Res Lab, Div Plasma Phys, Washington, DC 20375 USA. Sachs Freeman Associates Inc, Landover, MD 20785 USA. Res Support Instruments, Lanham, MD 20706 USA. Maxwell Labs Inc, La Jolla, CA 92038 USA. RP Grun, J (reprint author), USN, Res Lab, Div Plasma Phys, Washington, DC 20375 USA. NR 26 TC 6 Z9 6 U1 0 U2 0 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 2420 EP 2427 DI 10.1063/1.367001 PG 8 WC Physics, Applied SC Physics GA YZ942 UT WOS:000072310700006 ER PT J AU Parker, EC Survanshi, SS Massell, PB Weathersby, PK AF Parker, EC Survanshi, SS Massell, PB Weathersby, PK TI Probabilistic models of the role of oxygen in human decompression sickness SO JOURNAL OF APPLIED PHYSIOLOGY LA English DT Article DE oxygen effects; gas-exchange kinetics; risk function; hazard function ID DIVES; TIME; AIR AB Probabilistic models of human decompression sickness (DCS) have been successful in describing DCS risk observed across a wide variety of N-2-O-2 dives but have failed to account for the observed DCS incidence in dives with high For, during decompression. Our most successful previous model, calibrated with 3,322 N-2-O-2 dives, predicts only 40% of the observed incidence in dives with 100% O-2 breathing during decompression. We added 1,013 O-2 decompression dives to the calibration data. Fitting the prior model to this expanded data set resulted in only a modest improvement in DCS prediction of O-2 data. Therefore, two O-2-specific modifications were proposed: Po-2-based alteration of inert gas kinetics (model 1) and Po-2 contribution to total inert gas (model 2). Both modifications statistically significantly improved the fit, and each predicts 90% of the observed DCS incidence in Oa dives. The success of models 1 and 2 in improving prediction of DCS occurrence suggests that elevated Po, levels contribute to DCS risk, although less than the equivalent amount of Nz. Both models allow rational optimization of O-2 use in accelerating decompression procedures. C1 USN, Med Res Inst, Albert R Behnke Diving Med Res Ctr, Bethesda, MD 20889 USA. RP Parker, EC (reprint author), USN, Med Res Inst, Albert R Behnke Diving Med Res Ctr, 8901 Wisconsin Ave, Bethesda, MD 20889 USA. NR 19 TC 27 Z9 27 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 MAR PY 1998 VL 84 IS 3 BP 1096 EP 1102 PG 7 WC Physiology; Sport Sciences SC Physiology; Sport Sciences GA YZ674 UT WOS:000072279000045 PM 9480974 ER PT J AU Gilardi, RD Butcher, RJ AF Gilardi, RD Butcher, RJ TI A new class of flexible energetic salts, part 3: The crystal structures of the 3,3-dinitroazetidinium dinitramide and 1-i-propyl-3,3-dinitroazetidinium dinitramide salts SO JOURNAL OF CHEMICAL CRYSTALLOGRAPHY LA English DT Article DE azetidine structures; substituted azetidines; azetidinium salts; dinitramide salts ID THERMOCHEMISTRY; BASES AB The crystal structures of 3,3-dinitroazetidinium, 1, and 1-i-propyl-3,3-dinitroazetidinium dinitramide, 2, have been determined. 1 crystallizes in the orthorhombic space group Cmc2(1) with cell dimensions a = 9.932(1), b = 8.545(1), c = 11.107(1) Angstrom, while 2 crystallizes in the orthorhombic space group Pbca with cell dimensions a = 11.464(2), b = 11.657(2), c = 17.916(4) Angstrom. Compound 2 formed spontaneously from 1 by reacting with the solvent, acetone, during attempts to recrystallize it. The conformations adopted by the dinitramide ions are quite different with the bend, twist, and torsion angles for the dinitramide ion in 1 being much smaller than those in 2. Possible reasons for the dramatic differences in conformations observed in 1 and 2 are the different local symmetries for this ion found in the two structures as well as the absence of hydrogen bonding interactions in 2. C1 USN, Res Lab, Struct Matter Lab, Washington, DC 20375 USA. Howard Univ, Dept Chem, Washington, DC 20059 USA. RP Gilardi, RD (reprint author), USN, Res Lab, Struct Matter Lab, Washington, DC 20375 USA. RI G, Neela/H-3016-2014 NR 39 TC 19 Z9 19 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1074-1542 J9 J CHEM CRYSTALLOGR JI J. Chem. Crystallogr. PD MAR PY 1998 VL 28 IS 3 BP 163 EP 169 DI 10.1023/A:1022410008353 PG 7 WC Crystallography; Spectroscopy SC Crystallography; Spectroscopy GA ZY194 UT WOS:000074595700001 ER PT J AU Copper, CL AF Copper, CL TI Capillary electrophoresis - Part I. Theoretical and experimental background SO JOURNAL OF CHEMICAL EDUCATION LA English DT Article ID IONIZATION MASS-SPECTROMETRY; AMINO-ACID ENANTIOMERS; ZONE ELECTROPHORESIS; ELECTROKINETIC CHROMATOGRAPHY; CHIRAL SEPARATION; PERFORMANCE; RESOLUTION; TEMPERATURE; OPTIMIZATION; LIQUID C1 USN Acad, Dept Chem, Annapolis, MD 21402 USA. RP Copper, CL (reprint author), USN Acad, Dept Chem, Annapolis, MD 21402 USA. NR 50 TC 14 Z9 14 U1 1 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0021-9584 J9 J CHEM EDUC JI J. Chem. Educ. PD MAR PY 1998 VL 75 IS 3 BP 343 EP 347 PG 5 WC Chemistry, Multidisciplinary; Education, Scientific Disciplines SC Chemistry; Education & Educational Research GA YW776 UT WOS:000071972900027 ER PT J AU Copper, CL Whitaker, KW AF Copper, CL Whitaker, KW TI Capillary electrophoresis: Part II. Applications SO JOURNAL OF CHEMICAL EDUCATION LA English DT Article ID POLYCYCLIC AROMATIC-HYDROCARBONS; SEPARATIONS; CHROMATOGRAPHY C1 USN Acad, Annapolis, MD 21402 USA. Univ Tennessee, Knoxville, TN 37996 USA. RP Copper, CL (reprint author), USN Acad, Annapolis, MD 21402 USA. NR 26 TC 8 Z9 8 U1 1 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0021-9584 J9 J CHEM EDUC JI J. Chem. Educ. PD MAR PY 1998 VL 75 IS 3 BP 347 EP 351 PG 5 WC Chemistry, Multidisciplinary; Education, Scientific Disciplines SC Chemistry; Education & Educational Research GA YW776 UT WOS:000071972900028 ER PT J AU Baronavski, AP Owrutsky, JC AF Baronavski, AP Owrutsky, JC TI Vibronic dependence of the (B)over-tilde state lifetimes of CH(3)I and CD(3)I using femtosecond photoionization spectroscopy SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID INTRAMOLECULAR PREDISSOCIATION DYNAMICS; ENHANCED MULTIPHOTON IONIZATION; HYPER-RAMAN SCATTERING; PARENT BENDING MOTION; IODIDE B-STATE; METHYL-IODIDE; RYDBERG STATES; PHOTODISSOCIATION DYNAMICS; EMISSION-SPECTROSCOPY; 193.3 NM AB Tunable deep UV femtosecond photoionization spectroscopy with single photon excitation and wavelengths longer than 192 nm has been used to determine predissociation-mediated excited state lifetimes for many vibronic levels of the (B) over tilde (6s[2] Rydberg) state of CH(3)I and CD(3)I. These include states with vibrational excitation in the nu(1), nu(2), nu(3), and nu(6) modes. We have previously reported lifetime measurements for the origin bands [Chem. Phys. Lett. 222, 335 (1994)]. The vibronic and isotopic dependences presented here qualitatively agree with various aspects of results from two indirect measurements. Our results corroborate the counterintuitive result from the resonance Raman work by Wang and Ziegler [J. Chem. Phys. 95, 288 (1991)] that the level singly excited in the C-I stretching mode (3(1)) dissociates more slowly (we measure similar to 4.0 ps for both CH(3)I and CD(3)I) than the vibrationless levels (1.38 and 1.90 ps, respectively). In contrast to the resonance Raman results and similar to those from resonance enhanced multiphoton ionization linewidth studies by Syage [Chem. Phys. Lett. 212, 124 (1993)], we find a faster predissociation rate upon excitation in the nu(6) mode. The lifetimes are considerably longer than those measured for the higher lying 6p and 7s Rydberg states by femtosecond mass-resolved photoionization studies by Janssen et al. [Chem. Phys. Lett. 214, 281 (1994)]. In that case, a faster dissociation rate was measured for the 31 compared to the vibrationless level. This work provides further evidence of the multidimensional nature of the (B) over tilde state predissociation mechanism and an opportunity to critically test high level calculations of the Rydberg state photodissociation dynamics. (C) 1998 American Institute of Physics. [S0021-9606(98)01009-5]. C1 USN, Res Lab, Div Chem, Washington, DC 20375 USA. RP Baronavski, AP (reprint author), USN, Res Lab, Div Chem, Code 6111, Washington, DC 20375 USA. RI Owrutsky, Jeffrey/K-7649-2012 NR 61 TC 29 Z9 29 U1 1 U2 4 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD MAR 1 PY 1998 VL 108 IS 9 BP 3445 EP 3452 DI 10.1063/1.475744 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA YZ048 UT WOS:000072215000009 ER PT J AU Manger, P Sum, M Szymanski, M Ridgway, S Krubitzer, L AF Manger, P Sum, M Szymanski, M Ridgway, S Krubitzer, L TI Modular subdivisions of dolphin insular cortex: Does evolutionary history repeat itself? SO JOURNAL OF COGNITIVE NEUROSCIENCE LA English DT Article ID OCULAR DOMINANCE COLUMNS; HUMAN VISUAL-CORTEX; MANATEE CEREBRAL-CORTEX; CYTOCHROME-OXIDASE; SOMATOSENSORY CORTEX; ENTORHINAL CORTEX; ORGANIZATION; MONKEYS; SYSTEM; BRAIN AB The structural organization of the insular cortex in the bottlenose dolphin was investigated by examining Nissl-and myelin-stained tissue that was sectioned coronally and tangentially. An uneven distribution of cell clusters that coincided with myelin-light zones was observed in layer II. When the present observations were compared to descriptions of modules in other animals, we found that the range of module size is restricted, while the size of the brain, particularly the neocortex, varies dramatically. Indeed, despite the tremendous expansion of the cetacean neocortex, the size of the modules in the insular cortex is similar to that described for small-brained mammals like the mouse, suggesting that module size is evolutionarily stable across species. Selection for optimal-size processing units, in terms of the lengths of connections within and between them, is a likely source of this stability. C1 Univ Calif Davis, Ctr Neurosci, Davis, CA 95616 USA. US Navy, Command Control & Ocean Surveillance Ctr, Washington, DC 20350 USA. RP Krubitzer, L (reprint author), Univ Calif Davis, Ctr Neurosci, 1544 Newton Ct, Davis, CA 95616 USA. EM lakrubitzer@ucdavis.edu FU NINDS NIH HHS [1 RO1 NS35103-01A1] NR 73 TC 43 Z9 43 U1 0 U2 4 PU M I T PRESS PI CAMBRIDGE PA FIVE CAMBRIDGE CENTER, CAMBRIDGE, MA 02142 USA SN 0898-929X J9 J COGNITIVE NEUROSCI JI J. Cogn. Neurosci. PD MAR PY 1998 VL 10 IS 2 BP 153 EP 166 DI 10.1162/089892998562627 PG 14 WC Neurosciences; Psychology, Experimental SC Neurosciences & Neurology; Psychology GA ZG744 UT WOS:000073035000001 PM 9555104 ER PT J AU Chu, PC Fan, CW AF Chu, PC Fan, CW TI A three-point combined compact difference scheme SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article ID BOUNDARY-CONDITIONS AB A new three-point combined compact difference (CCD) scheme is developed for numerical models, The major features of the CCD scheme are: three paint, implicit. sixth-order accuracy, and inclusion of boundary values. Due to its combination of the first and second derivatives, the CCD scheme becomes more compact and more accurate than normal compact difference schemes. The efficient twin-tridiagonal (for calculating derivatives) and triple-tridiagonal (for solving partial difference equation with the CCD scheme) methods are also presented. Besides, the CCD scheme has sixth-order accuracy at periodic boundaries and fifth-order accuracy at nonperiodic boundaries, The possibility of extending to a three-point eighth-order scheme is also included. (C) 1998 Academic Press. C1 USN, Postgrad Sch, Dept Oceanog, Monterey, CA 93943 USA. RP Chu, PC (reprint author), USN, Postgrad Sch, Dept Oceanog, Monterey, CA 93943 USA. EM chu@nps.navy.mil NR 23 TC 119 Z9 128 U1 0 U2 12 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 MAR 1 PY 1998 VL 140 IS 2 BP 370 EP 399 DI 10.1006/jcph.1998.5899 PG 30 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA ZF789 UT WOS:000072933400007 ER PT J AU Xu, HHK Smith, DT Jahanmir, S Romberg, E Kelly, JR Thompson, VP Rekow, ED AF Xu, HHK Smith, DT Jahanmir, S Romberg, E Kelly, JR Thompson, VP Rekow, ED TI Indentation damage and mechanical properties of human enamel and dentin SO JOURNAL OF DENTAL RESEARCH LA English DT Article DE crack; dentino-enamel junction; enamel rod; fracture toughness; tooth orientation; modulus ID FRACTURE PROPERTIES; MATERIAL-REMOVAL; TOUGHNESS; HARDNESS; MICROSTRUCTURE; CERAMICS; JUNCTION; ALUMINA AB Understanding the mechanical properties of human teeth is important to clinical tooth preparation and to the development of "tooth-like" restorative materials. Previous studies have focused on the macroscopic fracture behavior of enamel and dentin. In the present study, we performed indentation studies to understand the microfracture and deformation and the microcrack-microstructure interactions of teeth. It was hypothesized that crack propagation would be influenced by enamel rods and the dentino-enamel junction (DEJ), and the mechanical properties would be influenced by enamel rod orientation and tooth-to-tooth variation. Twenty-eight human third molars were used for the measurement of hardness, fracture toughness, elastic modulus, and energy absorbed during indentation. We examined the effect of enamel rod orientation by propagating cracks in the occlusal surface, and in the axial section in directions parallel and perpendicular to the occlusal surface. The results showed that the cracks in the enamel axial section were significantly longer in the direction perpendicular to the occlusal surface than parallel. The cracks propagating toward the DEJ were always arrested and unable to penetrate dentin. The fracture toughness of enamel was not single-valued but varied by a factor of three as a function of enamel rod orientation. The elastic modulus of enamel showed a significant difference between the occlusal surface and the axial section. It is concluded that the cracks strongly interact with the DEJ and the enamel rods, and that the mechanical properties of teeth are functions of microstructural orientations; hence, single values of properties (e.g., a single toughness value or a single modulus value) should not be used without information on microstructural orientation. C1 Natl Inst Stand & Technol, Amer Dent Assoc Hlth Fdn, Paffenbarger Res Ctr, Gaithersburg, MD 20899 USA. Natl Inst Stand & Technol, Div Ceram, Gaithersburg, MD 20899 USA. Univ Maryland, Sch Dent, Dept Oral Hlth Care Delivery, Stat Grp, Baltimore, MD 21201 USA. USN, Sch Dent, Dept Prosthodont, Bethesda, MD 20889 USA. Univ Maryland, Sch Dent, Dept Restorat Dent, Baltimore, MD 21201 USA. Univ Med & Dent New Jersey, Dept Orthodont, Newark, NJ 07103 USA. RP Xu, HHK (reprint author), Natl Inst Stand & Technol, Amer Dent Assoc Hlth Fdn, Paffenbarger Res Ctr, Bldg 224,Room A-153, Gaithersburg, MD 20899 USA. RI Smith, Douglas/I-4403-2016; OI Smith, Douglas/0000-0002-9358-3449; Thompson, Van P/0000-0003-0033-0344 FU NIDCR NIH HHS [1 P01DE10976-01A1] NR 24 TC 300 Z9 313 U1 10 U2 47 PU AMER ASSOC DENTAL RESEARCH PI ALEXANDRIA PA 1619 DUKE ST, ALEXANDRIA, VA 22314 USA SN 0022-0345 J9 J DENT RES JI J. Dent. Res. PD MAR PY 1998 VL 77 IS 3 BP 472 EP 480 PG 9 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA YZ958 UT WOS:000072312300006 PM 9496920 ER PT J AU DeNunzio, M AF DeNunzio, M TI Topical anesthetic as an adjunct to local anesthesia during pulpectomies SO JOURNAL OF ENDODONTICS LA English DT Article ID PULP AB A technique is described using topical anesthetic to supplement local anesthesia. It is the author's opinion that it enhances patient comfort during pulpectomies on teeth with irreversible pulpitis. C1 Naval Dent Sch, Bethesda, MD USA. USN, Dent Corps, Washington, DC 20350 USA. RP DeNunzio, M (reprint author), 5180 Willow Run Dr, Pensacola, FL 32504 USA. NR 10 TC 5 Z9 5 U1 0 U2 1 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 MAR PY 1998 VL 24 IS 3 BP 202 EP 203 DI 10.1016/S0099-2399(98)80185-4 PG 2 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA YZ998 UT WOS:000072317600013 PM 9558589 ER PT J AU Keyser, DR AF Keyser, DR TI The systematic uncertainty of laboratory flow calibrations SO JOURNAL OF FLUIDS ENGINEERING-TRANSACTIONS OF THE ASME LA English DT Article AB There are two axioms applicable to this paper: the first is that no flowmeter can be more accurate than the laboratory which calibrated it; the second that no uncalibrated flowmeter can be more accurate than a like one that is calibrated in a recognized standards laboratory. The fundamental systematic uncertainty in flow measurement is that inherited from the flow calibration laboratory. This paper focuses on ascertaining this fundamental systematic uncertainty by deriving from the published instances of interlaboratory comparisons a value in which one may be 95 percent confident. For water flow measurements, this value turns out To be +/-0.28 percent, and for liquid hydrocarbon fuels it is +/-0.77 percent. Cold water calibrations are the most accurate. C1 USN, Air Warfare Ctr, Div Aircraft, Patuxent River, MD 20670 USA. RP Keyser, DR (reprint author), USN, Air Warfare Ctr, Div Aircraft, Patuxent River, MD 20670 USA. NR 12 TC 0 Z9 0 U1 0 U2 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0098-2202 J9 J FLUID ENG-T ASME JI J. Fluids Eng.-Trans. ASME PD MAR PY 1998 VL 120 IS 1 BP 19 EP 22 DI 10.1115/1.2819647 PG 4 WC Engineering, Mechanical SC Engineering GA ZE038 UT WOS:000072751100003 ER PT J AU Abraham, BM Keith, WL AF Abraham, BM Keith, WL TI Direct measurements of turbulent boundary layer wall pressure wavenumber-frequency spectra SO JOURNAL OF FLUIDS ENGINEERING-TRANSACTIONS OF THE ASME LA English DT Article ID FLUCTUATIONS AB Direct measurements of streamwise wavenumber-frequency spectra of turbulent wall pressure fluctuations were made in an acoustically quiet water tunnel. A linear army of evenly spaced flush mounted pressure sensors was used to measure the wall pressure field at 48 streamwise locations. This array provided over 24 dB of resolution resolution (sidelobe rejection) in the wavenumber domain, leading to an accurate estimate of the "convective ridge" and part of the subconvective and low wavenumber portions of the spectrum at discrete frequencies. Boundary layer parameters, including the mean wall shear stress, boundary layer thickness, displacement thickness, and momentum thickness, were derived from mean streamwise velocity measurements for 8100 < R-theta < 16, 700. Time and length scales derived from these parameters were used to nondimensionalize the measured spectra. The effectiveness of different scalings for nondimensionalizing the low and convective wavenumber regions at discrete frequencies was evaluated. C1 USN, Ctr Underwater Syst, Submarine Sonar Dept, Div Newport, Newport, RI 02841 USA. RP Abraham, BM (reprint author), USN, Ctr Underwater Syst, Submarine Sonar Dept, Div Newport, Newport, RI 02841 USA. NR 30 TC 31 Z9 34 U1 0 U2 2 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0098-2202 J9 J FLUID ENG-T ASME JI J. Fluids Eng.-Trans. ASME PD MAR PY 1998 VL 120 IS 1 BP 29 EP 39 DI 10.1115/1.2819657 PG 11 WC Engineering, Mechanical SC Engineering GA ZE038 UT WOS:000072751100005 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 Savarino, SJ Brown, FM Hall, E Bassily, S Youssef, F Wierzba, T Peruski, L El-Masry, NA Safwat, M Rao, M Jertborn, M Svennerholm, AM Lee, YJ Clemens, JD AF Savarino, SJ Brown, FM Hall, E Bassily, S Youssef, F Wierzba, T Peruski, L El-Masry, NA Safwat, M Rao, M Jertborn, M Svennerholm, AM Lee, YJ Clemens, JD TI Safety and immunogenicity of an oral, killed enterotoxigenic Escherichia coli - Cholera toxin B subunit vaccine in Egyptian adults SO JOURNAL OF INFECTIOUS DISEASES LA English DT Article; Proceedings Paper CT 96th Annual General Meeting of the American-Society-for-Microbiology CY MAY 19-24, 1996 CL NEW ORLEANS, LOUISIANA SP Amer Soc Microbiol ID ANTIBODY-SECRETING CELLS; IMMUNOSORBENT-ASSAY; DIARRHEA; IMMUNIZATION AB Enterotoxigenic Escherichia coli (ETEC) is the leading cause of bacterial diarrhea in young children in developing countries. The safety and immunogenicity of a killed, oral ETEC vaccine consisting of whole cells plus recombinantly produced cholera toxin B subunit (rCTB) was evaluated in Egypt, which is endemic for ETEC diarrhea. Seventy-four healthy Egyptian adults (21-45 years old) were randomized and received two doses of the ETEC/rCTB vaccine (E003) or placebo 2 weeks apart. The frequency of adverse events after either dose did not differ by treatment group, and no severe adverse events were reported. After vaccination, peripheral blood IgA B cell responses to CTB (100%) and to vaccine colonization factor antigens CFA/I (94%), CS4 (100%), CS2 (81%), and CS1 (69%) were significantly higher than response rates for the placebo group. These favorable results in Egyptian adults indicate that the ETEC/rCTB vaccine is a promising candidate for evaluation in younger age groups in this setting. C1 USN, Med Res Unit 3, Cairo, Egypt. Eqyptian Minist Hlth, Benha, Egypt. NICHHD, NIH, Bethesda, MD 20892 USA. Gothenburg Univ, Gothenburg, Sweden. RP Savarino, SJ (reprint author), USN, Med Res Unit 3, PSC 452,Box 127, FPO, AE 09835 USA. FU NICHD NIH HHS [HD-0026-01] NR 14 TC 56 Z9 57 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 MAR PY 1998 VL 177 IS 3 BP 796 EP 799 PG 4 WC Immunology; Infectious Diseases; Microbiology SC Immunology; Infectious Diseases; Microbiology GA YY555 UT WOS:000072159900042 PM 9498468 ER PT J AU Suits, BH Garroway, AN Miller, JB AF Suits, BH Garroway, AN Miller, JB TI Noise-immune coil for unshielded magnetic resonance measurements SO JOURNAL OF MAGNETIC RESONANCE LA English DT Article DE NQR; noise pickup; surface coil; split-loop resonator; RDX AB A modified split-loop resonator that is electrically balanced and that has no magnetic dipole moment is shown to be relatively immune to environmental noise. Using a magnetic resonance surface coil of this design for N-14 NQR at 3.4 MHz, it is demonstrated that magnetic resonance measurements can be made in the laboratory without additional RF shielding and with less than a 2 dB increase in the rms noise. Compared to more traditional designs, the modified split-loop resonator showed a net 17-dB gain in sensitivity for unshielded measurements. (C) 1998 Academic Press. C1 USN, Res Lab, Div Chem, Washington, DC 20375 USA. Michigan Technol Univ, Dept Phys, Houghton, MI 49931 USA. RP Suits, BH (reprint author), USN, Res Lab, Div Chem, Washington, DC 20375 USA. NR 6 TC 28 Z9 28 U1 0 U2 3 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 1090-7807 J9 J MAGN RESON JI J. Magn. Reson. PD MAR PY 1998 VL 131 IS 1 BP 154 EP 158 DI 10.1006/jmre.1997.1335 PG 5 WC Biochemical Research Methods; Physics, Atomic, Molecular & Chemical; Spectroscopy SC Biochemistry & Molecular Biology; Physics; Spectroscopy GA ZH656 UT WOS:000073133900021 ER PT J AU Curlee, C AF Curlee, C TI Primary care for women. SO JOURNAL OF NURSE-MIDWIFERY LA English DT Book Review C1 USN, Med Ctr, San Diego, CA 92152 USA. RP Curlee, C (reprint author), USN, Med Ctr, San Diego, CA 92152 USA. NR 1 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 0091-2182 J9 J NURSE-MIDWIFERY JI J. Nurse-Midwifery PD MAR-APR PY 1998 VL 43 IS 2 BP 133 EP 134 PG 2 WC Nursing SC Nursing GA ZJ888 UT WOS:000073263800018 ER PT J AU Wagener, JS AF Wagener, JS TI Inhaled steroids in children: Risks versus rewards SO JOURNAL OF PEDIATRICS LA English DT Editorial Material ID BECLOMETHASONE DIPROPIONATE; ASTHMATIC-CHILDREN; LUNG-FUNCTION; GROWTH; CORTICOSTEROIDS C1 USN Hosp, Med Corp, San Diego, CA 92134 USA. Univ Colorado, Sch Med, Denver, CO 80218 USA. RP Wagener, JS (reprint author), Univ Colorado, Sch Med, Denver, CO 80218 USA. NR 18 TC 11 Z9 12 U1 0 U2 2 PU MOSBY-ELSEVIER PI NEW YORK PA 360 PARK AVENUE SOUTH, NEW YORK, NY 10010-1710 USA SN 0022-3476 EI 1097-6833 J9 J PEDIATR-US JI J. Pediatr. PD MAR PY 1998 VL 132 IS 3 BP 381 EP 383 DI 10.1016/S0022-3476(98)70003-4 PN 1 PG 3 WC Pediatrics SC Pediatrics GA ZF241 UT WOS:000072877800003 PM 9544884 ER PT J AU Kodres, CA Murphy, GL AF Kodres, CA Murphy, GL TI Jet-engine test cell augmenter performance SO JOURNAL OF PROPULSION AND POWER LA English DT Article AB The prime gauge of jet-engine test cell performance is the ability to provide repeatable results of the engine measurements. Based on this criterion, the U.S. military test cells are among the finest air-cooled turbojet test facilities in the world, But this high performance is being achieved at a relatively high cost, Switching from a round or obround augmenter tube to a square or rectangular tube will save up to 30% in construction and maintenance costs. Performance as well as cost, however, must be considered, and the objective of this work is to quantitatively assess the aerothermal performance of the rectangular tube, Round, square, and rectangular augmenter tubes of similar dimensions are compared using a mathematical model of the U.S. Navy's standard jet-engine test cell. Both the square and rectangular tubes are found to be acceptable alternatives. C1 USN, Facil Engn Serv Ctr, Pollut Prevent Div, Port Hueneme, CA 93043 USA. USN, Facil Engn Serv Ctr, Facil Syst Div, Port Hueneme, CA 93043 USA. RP Kodres, CA (reprint author), USN, Facil Engn Serv Ctr, Pollut Prevent Div, Port Hueneme, CA 93043 USA. NR 11 TC 5 Z9 5 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 MAR-APR PY 1998 VL 14 IS 2 BP 129 EP 134 DI 10.2514/2.5267 PG 6 WC Engineering, Aerospace SC Engineering GA ZB675 UT WOS:000072496300001 ER PT J AU Tuncer, IH Platzer, MF VanDyken, RD AF Tuncer, IH Platzer, MF VanDyken, RD TI Navier-Stokes analysis of subsonic flowfields over a missile configuration SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article; Proceedings Paper CT AIAA 35th Aerospace Science Meeting / Nonlinear Dynamical Systems Symposium CY JAN 06-10, 1997 CL RENO, NEVADA SP Amer Inst Aeronaut & Astronaut, USAF, Off Sci Res, Sandia Natl Labs AB Subsonic flowfields over a missile configuration are computed at high angles of attack ranging from 15 to 60 deg with the NASA Ames Research Center OVERFLOW Navier-Stokes solver. The computed flowfields are presented in terms of particle traces, helicity contours; and surface streamlines. The dow separation over the missile body, the development of leeward-side vortex patterns, and the canard and tail vortices and their interaction are identified. The computed normal force and pitching moment coefficients compare well with the experimental data at an incidence of 15 deg; At higher incidences the normal force is underpredicted by up to 15%. The computed pitching moments agree qualitatively well with the,experimental data, but Percentage deviations are substantial in the higher incidence range. C1 USN, Postgrad Sch, Dept Aeronaut & Astronaut, Monterey, CA 93943 USA. USN, Air Warfare Ctr, Weapons Div, China Lake, CA 93555 USA. RP Tuncer, IH (reprint author), USN, Postgrad Sch, Dept Aeronaut & Astronaut, Monterey, CA 93943 USA. NR 11 TC 1 Z9 1 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 127 EP 131 DI 10.2514/2.3318 PG 5 WC Engineering, Aerospace SC Engineering GA ZG315 UT WOS:000072989000002 ER PT J AU Moore, FG Hymer, TC AF Moore, FG Hymer, TC TI Improved methodology for axial force prediction at angle of attack SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article AB An improved semiempirical method for axial force calculation on missile configurations has been developed. The method uses the theoretical methods currently used in the U.S. Naval Surface Warfare Center's aeroprediction code for zero angle-of-attack axial force computations and several wind-tunnel databases to compute changes in axial force at angle of attack. The method is applicable to bodies alone, wing-body, and wing-body-tail configurations for both zero and nonzero control deflections. It has been developed to allow computation for angle of attack up to 90 deg at Mach numbers up to 20. However, it has been validated against data only to Mach number of 4.6 and angle of attack to 40 deg for all configurations. For body alone and wing-body cases, it has been validated to 90 deg angle of attack. Additional test data or Navier-Stokes computations would allow refinement of the improved method. The new method has been compared with several existing techniques. The method was found to be as good as or better than existing techniques but more general than existing methods in terms of configurations and Mach numbers allowed for the method to be used. C1 USN, Ctr Surface Warfare, Weapons Syst Dept, Dahlgren Div, Dahlgren, VA 22448 USA. USN, Ctr Surface Warfare, Aeromech Branch, Weapons Syst Dept, Dahlgren, VA 22448 USA. RP Moore, FG (reprint author), USN, Ctr Surface Warfare, Weapons Syst Dept, Dahlgren Div, Dahlgren, VA 22448 USA. NR 19 TC 0 Z9 1 U1 0 U2 1 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 132 EP 139 DI 10.2514/2.3320 PG 8 WC Engineering, Aerospace SC Engineering GA ZG315 UT WOS:000072989000003 ER PT J AU Gopinath, A Tait, NL Garrett, SL AF Gopinath, A Tait, NL Garrett, SL TI Thermoacoustic streaming in a resonant channel: The time-averaged temperature distribution SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article ID PRIME MOVER; SELF-OSCILLATION; HEAT ENGINES; REFRIGERATORS; WORKING; STACKS; HELIUM; ONSET; TUBE; FLOW AB The problem of thermoacoustic streaming in a plane parallel resonant channel, representative of the stack in a thermoacoustic engine, has been developed in a general dimensionless form. The utility of such a formulation and its wide ranging applicability to different solid-fluid combinations is demonstrated by which a consistent account of all the energy-exchange mechanisms can be made. Certain (wide-gap, thick-wall) simplifications are initially made to arrive at more manageable forms of the time-averaged temperature distributions of interest in both the fluid gap, and the channel walls. These simplifications clarify the origin of the thermoacoustic effect and provide a description of the responsible physical mechanisms based on which the validity of the "bucket-brigade" model is examined. The unexpected role of a little-known second-order thermal expansion coefficient is pointed out. It is shown that the conjugate wall-fluid coupling is crucial in yielding the large time-averaged axial temperature gradients that can be induced in the channel. In particular, the heat transfer rates at the ends of the channel are found to play an important role in determining the magnitude of these time-averaged gradients. The more general and practically useful case of arbitrary channel gap widths is also treated and it is found that for ideal gas working fluids there is an optimum channel gap width for which the axial thermal stratification in the channel is maximized. A comparison of the predictions from this study with available experimental data shows very good agreement. (C) 1998 Acoustical Society of America. [S0001-4966(98)02203-6]. C1 USN, Postgrad Sch, Dept Mech Engn, Monterey, CA 93943 USA. Penn State Univ, Grad Program Acoust, State Coll, PA 16804 USA. RP Gopinath, A (reprint author), USN, Postgrad Sch, Dept Mech Engn, Code ME Gk, Monterey, CA 93943 USA. NR 44 TC 24 Z9 25 U1 0 U2 3 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 MAR PY 1998 VL 103 IS 3 BP 1388 EP 1405 DI 10.1121/1.421298 PG 18 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA ZB933 UT WOS:000072522900019 ER PT J AU Guillot, FM Jarzynski, J Balizer, E AF Guillot, FM Jarzynski, J Balizer, E TI Electromechanical response of polymer films by laser Doppler vibrometry SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article AB A two-sided laser Doppler vibrometer (LDV) was designed to measure the d(33) electromechanical coupling coefficient of piezoelectric and electrostrictive thin films. Optical fibers and optical fiber couplers were used to split the light into multiple beams and to simultaneously illuminate the same spot on both sides of the film. This probe measured the normal displacement on each side of the sample and allowed computation of the change in thickness by summing the two LDV signals. Data for PVDF films are presented to illustrate problems associated with this type of measurement A large bending motion of the sample occurred which was responsible for a significant error in the measured thickness change. Reducing the amplitude of this motion by stacking films was an efficient way to increase the accuracy of the data. An error analysis was carried out to qualitatively explain these experimental observations. It was also discovered that the measurement accuracy improved when the ac driving voltage frequency was less than the bending resonance frequency of the sample. (C) 1998 Acoustical Society of America. [S0001-4966(98)01303-4]. C1 Georgia Inst Technol, Sch Mech Engn, Atlanta, GA 30332 USA. USN, Ctr Surface Warfare, Silver Spring, MD 20903 USA. RP Guillot, FM (reprint author), Georgia Inst Technol, Sch Mech Engn, Atlanta, GA 30332 USA. NR 11 TC 10 Z9 10 U1 0 U2 9 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 MAR PY 1998 VL 103 IS 3 BP 1421 EP 1427 DI 10.1121/1.421282 PG 7 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA ZB933 UT WOS:000072522900022 ER PT J AU Manry, CW Broschat, SL AF Manry, CW Broschat, SL TI Inverse imaging of the breast with a material classification technique SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article ID DIFFRACTION TOMOGRAPHY; MOMENT METHOD; SINC BASIS; EQUATION AB In recent publications [Chew et al., IEEE Trans. Blomed. Eng, BME-9, 218-225 (1990); Borup et al., Ultrason. Imaging 14, 69-55 (1992)] the inverse imaging problem has been solved by means of a two-step iterative method. In this paper, a third step is introduced for ultrasound imaging of the breast. In this step, which is based on statistical pattern recognition, classification of tissue types and a priori knowledge of the anatomy of the breast are integrated into the iterative method. Use of this material classification technique results in more rapid convergence to the inverse solution-approximately 40% fewer iterations are required-as well as greater accuracy. In addition, tumors an detected early in the reconstruction process. Results for reconstructions of a simple two-dimensional model of the human breast are presented. These reconstructions are extremely accurate when system noise and variations in tissue parameters an not too great. However, for the algorithm used, degradation of the reconstructions and divergence from the correct solution occur when system noise and variations in parameters exceed threshold values. Even in this case, however, tumors are still identified within a few iterations. (C) 1998 Acoustical Society of America. C1 USN, SPAWARSYSCEN D851 PL MR, San Diego, CA 92152 USA. Washington State Univ, Sch Elect Engn & Comp Sci, Pullman, WA 99164 USA. RP Manry, CW (reprint author), USN, SPAWARSYSCEN D851 PL MR, 53560 Hull St, San Diego, CA 92152 USA. EM cmanry@spawar.navy.mil; shira@eecs.wsu.edu NR 22 TC 6 Z9 6 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD MAR PY 1998 VL 103 IS 3 BP 1538 EP 1546 DI 10.1121/1.423110 PG 9 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA ZB933 UT WOS:000072522900035 PM 9514017 ER PT J AU Gaunaurd, GC Brill, D Huang, H Moore, PWB Strifors, HC AF Gaunaurd, GC Brill, D Huang, H Moore, PWB Strifors, HC TI Signal processing of the echo signatures returned by submerged shells insonified by dolphin "clicks": Active classification SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article ID SCATTERING; DISTRIBUTIONS AB A large set of dolphin-emitted acoustic pulses ("echolocation clicks") have been examined, which were reflected from various elastic shells that were suspended, underwater, 4.5 m in front of the animal in a large test site in Kaneohe Bay, Hawaii. A carefully instrumented analog-to-digital system continuously captured the emitted clicks and also the returned, backscattered echoes (A/D conversion at 500 kHz). Using standard conditioning techniques and food reinforces, the dolphin is taught to push an underwater paddle when the "correct" target-the one he has been trained to identify-is presented to him. He communicates his consistently correct identifying choices in this manner. Many echoes returned by three types of cylindrical shells in both the time and frequency domains as well as in the joint time-frequency (t-f) domain, by means of Wigner-type distributions have been examined. It will be shown exactly how specific features observable in these displays are directly related to the physical characteristics of the shells. This processing takes advantage of certain fundamental resonance principles to show which echo features contain information about the size, shape, wall thickness, and material composition of both the shell and its filler substance. In the same fashion that these resonance features give the identifying characteristics of each shell, it is believed they may also give them to the dolphin. These echo features may allow him to extract the target properties by inspection without any need for computations. It is claimed that this may be the fundamental physical explanation of the dolphin's amazing target ID feats, upon which they base their recognition choices. This claim may be substantiated by the detailed analysis of many typical echoes returned by various shells, when they are interrogated by several dolphins. Thus far, this analysis of many echoes from many shells has only been carried out for a single dolphin. (C) 1998 Acoustical Society of America. C1 USN, Ctr Surface Warfare, Silver Spring, MD 20903 USA. USN, Command Control & Ocean Syst Ctr, NRaD, San Diego, CA 92152 USA. Natl Def Res Estab, S-17290 Stockholm, Sweden. RP Gaunaurd, GC (reprint author), USN, Ctr Surface Warfare, Carderock Div, Code 684,9500 MacArthur Blvd, W Bethesda, MD 20817 USA. NR 16 TC 12 Z9 14 U1 1 U2 3 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 MAR PY 1998 VL 103 IS 3 BP 1547 EP 1557 DI 10.1121/1.421302 PG 11 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA ZB933 UT WOS:000072522900036 PM 9514018 ER PT J AU Kumar, A Fox, AG AF Kumar, A Fox, AG TI Microstructural study of the hot corrosion of a calcium aluminosilicate glass-ceramic and a Si-C-O-fiber-reinforced calcium aluminosilicate matrix composite via sodium sulfate in air and argon at 900 degrees C SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID MAGNESIUM ALUMINOSILICATES; PROPERTY RELATIONSHIPS; MECHANICAL-BEHAVIOR; NICALON FIBERS; STRENGTH; 1000-DEGREES-C AB The hot corrosion of a calcium aluminosilicate (GAS) glass-ceramic and a composite of CAS matrix that has been reinforced with Si-C-O (Nicalon) fiber has been investigated by X-ray diffractometry, scanning electron microscopy, and transmission electron microscopy. Samples of the monolithic CAS and the Si-C-O-CAS composite were subjected to corrosion using liquid sodium sulfate at 900 degrees C for 50 h in air and argon environments, The monolithic and composite samples both were corroded by sodium sulfate, and corrosion damage in the composites was more severe than in the monolithic GAS, irrespective of the gaseous environment, The increased corrosion damage in the composites was due to the presence of Si-C-O fibers, which changes the mechanism of corrosion. The corrosion products in monolithic CAS were different from those in the composites; this disparity was also due to the presence of the fibers in the composite, The corrosion zones in all the samples were severely cracked, and the cracks extended into the unaffected regions of the samples, Mechanisms of hot corrosion have been proposed and discussed for both the monolithic and composite samples. C1 USN, Postgrad Sch, Dept Mech Engn, Ctr Mat Sci & Engn, Monterey, CA 93943 USA. RP Kumar, A (reprint author), IBM Corp, C7M-013,5600 Cottle Rd, San Jose, CA 95193 USA. NR 35 TC 0 Z9 0 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 MAR PY 1998 VL 81 IS 3 BP 613 EP 623 PG 11 WC Materials Science, Ceramics SC Materials Science GA ZC554 UT WOS:000072592300021 ER PT J AU Cobb, MA Petry, FE AF Cobb, MA Petry, FE TI Modeling spatial relationships within a fuzzy framework SO JOURNAL OF THE AMERICAN SOCIETY FOR INFORMATION SCIENCE LA English DT Article ID DATABASES AB In this article, we present a model for defining and representing binary topological and directional relationships between P-dimensional objects that is used to provide a basis for fuzzy querying capabilities. The definition of the relationships is based on an extension of Alien's temporal relations (Alien, 1983) to the spatial domain. This is done by allowing each of Alien's 13 relations to represent the interaction of P-dimensional objects in terms of an x and y relationship component. The resulting set of relationships is then used for defining topological and directional relationship terminology. A data structure called an abstract spatial graph (ASG) is defined for the binary relationships that maintains all necessary information regarding topology and direction. Abstract spatial graphs provide the basis for processing of fuzzy topological and directional queries. C1 USN, Res Lab, Mapping Sci Sect, Stennis Space Ctr, MS 39529 USA. Tulane Univ, Ctr Intelligent & Knowledge Based Syst, New Orleans, LA 70118 USA. RP Univ So Mississippi, Dept Comp Sci & Stat, Hattiesburg, MS 39406 USA. EM cobb@nrlssc.navy.mil; petry@cs.tulane.edu RI Petry, Frederick/F-9894-2010 NR 34 TC 27 Z9 28 U1 2 U2 2 PU JOHN WILEY & SONS INC PI HOBOKEN PA 111 RIVER ST, HOBOKEN, NJ 07030 USA SN 0002-8231 J9 J AM SOC INFORM SCI JI J. Am. Soc. Inf. Sci. PD MAR PY 1998 VL 49 IS 3 BP 253 EP 266 PG 14 WC Computer Science, Information Systems; Information Science & Library Science SC Computer Science; Information Science & Library Science GA YW793 UT WOS:000071974600006 ER PT J AU Barton, O Raouf, RA AF Barton, O Raouf, RA TI Vibration of variable thickness orthotropic plates using eigensensitivity analysis SO JOURNAL OF THERMOPLASTIC COMPOSITE MATERIALS LA English DT Article ID RECTANGULAR-PLATES; DIFFERENTIAL QUADRATURE; NONUNIFORM THICKNESS; VARYING THICKNESS AB An approximate closed-form expression is presented which can be used to compute the fundamental frequency of orthotropic laminates of variable thickness. The quadratic expression is derived for a laminate with a general thickness variation in one direction, and explicit results are provided for a laminate with a linear thickness variation. The desired expression is determined by casting the governing differential equation into discrete form using the Ritz method and expanding the discrete equations in a Maclaurin series about the off-diagonal elements of both the stiffness and mass matrices. Simply supported and clamped boundary conditions are analyzed using both beam shape functions and orthogonal polynomials. Results are compared with those obtained numerically using the Rayleigh-Ritz approach for several laminate tapers xi and plate aspect ratios R. C1 USN Acad, Dept Mech Engn, Annapolis, MD 21402 USA. RP Barton, O (reprint author), USN Acad, Dept Mech Engn, Annapolis, MD 21402 USA. NR 13 TC 0 Z9 0 U1 0 U2 1 PU TECHNOMIC PUBL CO INC PI LANCASTER PA 851 NEW HOLLAND AVE, BOX 3535, LANCASTER, PA 17604 USA SN 0892-7057 J9 J THERMOPLAST COMPOS JI J. Thermoplast. Compos. Mater. PD MAR PY 1998 VL 11 IS 2 BP 185 EP 197 PG 13 WC Materials Science, Composites SC Materials Science GA ZC043 UT WOS:000072533800007 ER PT J AU Johnstone, PAS Powell, CR Riffenburgh, R Rohde, DC Kane, CJ AF Johnstone, PAS Powell, CR Riffenburgh, R Rohde, DC Kane, CJ TI Second primary malignancies in T1-3N0 prostate cancer patients treated with radiation therapy with 10-year followup SO JOURNAL OF UROLOGY LA English DT Article DE prostatic neoplasms; radiotherapy; lymph nodes; neoplasm metastasis ID ASSOCIATION; BLADDER; CARCINOMA; TUMORS AB Purpose: The risk of patients with prostate cancer to have second primary malignancies is unclear. Population and autopsy based studies have shown no increased risk, which is at variance with several institutional analyses. A retrospective review was performed With comparison to expected cancer data from the Connecticut Tumor Registry. Materials and Methods: Records of a cohort of prostate cancer patients treated with staging pelvic lymphadenectomy and definitive radiotherapy between November 1, 1974 and July 7, 1987 were reviewed. Median potential followup from date of diagnosis was 10.9 years. Results: Of the 164 patients 150 (91.5%) had followup to death or to August 1995, with data available in part on 4 of the remaining patients. In 43 patients 51 second primary malignancies developed. Increased frequency of lymphomas, and kidney, bladder and rectal lesions (all p <0.001) was observed concurrently with diagnosis of prostate cancer, although this may be due to bias since full staging for the prostate cancer mag have led to their diagnosis. An increased frequency of renal lesions in the 1 to 4-year followup period (p = 0.032) also was observed. Two sarcomas and a leukemia were putatively radiation induced but their frequency was not significantly different from the comparison baseline. Conclusions: Much of the apparent increase in second primary malignancies associated with prostate cancer noted by some authors may be attributed to bias in the staging process. Renal cancers may occur more frequently in patients with prostate cancer but the distribution of these lesions is inconsistent with a field defect mechanism of cancer induction. C1 USN, Div Radiat Oncol, Med Ctr, San Diego, CA 92134 USA. USN, Dept Urol, Med Ctr, San Diego, CA 92134 USA. USN, Dept Clin Invest, Med Ctr, San Diego, CA 92134 USA. Univ Calif San Diego, Div Radiat Oncol, San Diego, CA 92103 USA. RP Johnstone, PAS (reprint author), USN, Div Radiat Oncol, Med Ctr, San Diego, CA 92134 USA. NR 21 TC 27 Z9 28 U1 0 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 946 EP 949 DI 10.1016/S0022-5347(01)63777-7 PG 4 WC Urology & Nephrology SC Urology & Nephrology GA YW252 UT WOS:000071913700088 PM 9474189 ER PT J AU Pinkney, H Thompson, DA Robinson, BJ Mascher, P Simpson, PJ Myler, U Kang, JU Frankel, MY AF Pinkney, H Thompson, DA Robinson, BJ Mascher, P Simpson, PJ Myler, U Kang, JU Frankel, MY TI Characterization of annealed high-resistivity InP grown by He-plasma-assisted epitaxy SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article; Proceedings Paper CT 8th Canadian Semiconductor Technology Conference CY AUG 12-15, 1997 CL OTTAWA, CANADA AB In this work we report on the effect of annealing high-resistivity InP grown by gas source molecular beam epitaxy in the presence of an electron cyclotron resonance generated He plasma, Previous work has shown that InP grown using this technique exhibits resistivity greater than 10(5) Ohm cm and Be-doped InGaAsP (lattice matched to InP, band-gap wavelength 1.5 mu m) exhibits subpicosecond carrier lifetime. This behavior is due to the presence of defects caused by the plasma particles during growth. To gain a better understanding of the nature of these defects, samples were annealed over the temperature range 500-700 degrees C and evaluated by variable energy positron annihilation measurements, transient ellipsometric surface photoreflectance, sheet resistance, and n-i-n device resistivity studies. For all samples. the resistivity increased with annealing, as did the carrier lifetime from the optical measurements which suggests the presence of more than one defect type in the material. Positron annihilation studies suggest that the open volume defects, present in the as-grown material as single vacancies and vacancy clusters, become larger upon annealing although this effect may be obscured in the Be-doped samples at higher annealing temperatures. The Be-doped samples were found to be mon resistive and optically faster than the undoped material, Also, the sheet resistance measurements may indicate that the Be in the doped samples is activated at annealing temperatures above 600 degrees C, since the material changes from weakly n-type to p-type. (C) 1995 American Vacuum Society. [S0734-2101(98)04002-0]. C1 McMaster Univ, Dept Engn Phys, Ctr Electrophoton Mat & Devices, Dept Engn Phys, Hamilton, ON L8S 4L7, Canada. Univ Western Ontario, Dept Phys, London, ON N6A 3K7, Canada. USN, Res Lab, Div Opt Sci, Washington, DC 20375 USA. RP Pinkney, H (reprint author), McMaster Univ, Dept Engn Phys, Ctr Electrophoton Mat & Devices, Dept Engn Phys, Hamilton, ON L8S 4L7, Canada. RI Kang, Jin/A-3228-2010; OI Mascher, Peter/0000-0002-8108-0334 NR 10 TC 5 Z9 5 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD MAR-APR PY 1998 VL 16 IS 2 BP 772 EP 775 DI 10.1116/1.581057 PG 4 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA ZC509 UT WOS:000072587200061 ER PT J AU Jensen, KL Abrams, RH Parker, RK AF Jensen, KL Abrams, RH Parker, RK TI Field emitter array development for high frequency applications SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article; Proceedings Paper CT 10th International Vacuum Microelectronics Conference (IVMC 97) CY AUG 17-21, 1997 CL KYONGJU, SOUTH KOREA ID AMPLIFIERS AB Radio frequency vacuum microelectronics combines the advantages of electron transport in vacuum with gated electron emission structures derived from solid-state microfabrication. The advent of practical gated vacuum emitters of micron size will have a strong impact on rf source technology. Next-generation rf amplifiers incorporating microfabricated emitters will allow amplifier designs that minimize the need for high-voltage power supplies, complex modulating circuitry, and the heavy magnets common with linear beam tubes. One attractive application for such efficient compact amplifiers is as the vacuum power booster of a microwave power module, a device that combines a solid-state preamplifier with a low-gain vacuum amplifier for efficiency. Program goals are to create a 50 W 10 GHz amplifier with 10 dB gain and efficiency exceeding 50%. We will survey the requirements placed on field emitter arrays for performance in a microwave amplifier as determined by various analyses, describe the present status of the performance of ring cathodes designed for inductive output amplifiers, i.e., the narrow-band, cavity-based klystrode under development at Varian/CPI and the wide-band, helix-based twystrode under development at NRL, and identify the challenges that remain before this new rf source technology is realized. [S0734-211X(98)02702-4]. C1 USN, Res Lab, Div Elect Sci & Technol, Washington, DC 20375 USA. RP Jensen, KL (reprint author), USN, Res Lab, Div Elect Sci & Technol, Code 6840, Washington, DC 20375 USA. EM kevin.jensen@nrl.navy.mil RI Jensen, Kevin/I-1269-2015 OI Jensen, Kevin/0000-0001-8644-1680 NR 12 TC 37 Z9 38 U1 0 U2 3 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 MAR-APR PY 1998 VL 16 IS 2 BP 749 EP 753 DI 10.1116/1.590217 PG 5 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA ZH976 UT WOS:000073167200054 ER PT J AU Kaihatu, JM Kirby, JT AF Kaihatu, JM Kirby, JT TI Two-dimensional parabolic modeling of extended Boussinesq equations SO JOURNAL OF WATERWAY PORT COASTAL AND OCEAN ENGINEERING-ASCE LA English DT Article ID LINEAR DISPERSION CHARACTERISTICS; NONLINEAR REFRACTION DIFFRACTION; WATER-WAVE PROPAGATION; SHALLOW-WATER; STOKES WAVES; FORM; APPROXIMATIONS; VERIFICATION; BATHYMETRY; EVOLUTION AB A frequency domain wave transformation model is derived from a set of time-dependent extended Boussinesq equations. In contrast to an earlier study, this model is derived directly from the (eta, u) form of the equations. The resulting model maintains the excellent dispersive properties of the original equations and also accurately mimics the shoaling behavior of dispersive linear theory for a wide range of water depths. The model is formulated in terms of a free parameter that can be tuned for optimum shoaling behavior. We tune the parameter in two ways; the first seeks the minimum error for the shoaling parameter while using the optimum value for the dispersion parameter, while the second seeks the minimum combined error for both dispersion and shoaling. These lead to two different sets of free parameters, with the second method leading to more favorable linear shoaling behavior than the first. The effectiveness of the linear terms of the model is demonstrated by using them, with both sets of free parameters, to propagate waves over a shoal; comparisons to both experimental data and a linear mild-slope parabolic model are performed, and agreement is favorable for both sets of parameters. The full model, with nonlinear terms and both sets of parameters, is then used to simulate a laboratory experiment involving harmonic generation and nonlinear wave focusing. Results indicate that the model can reproduce the characteristics of a lowest-order Kadomtsev-Petviashvili (KP) model in shallow water. The model also shows improved agreement with data relative to the KP model and another dispersive frequency-domain model in intermediate water depth. Additionally, there is little difference between the results from either set of parameters used in the model, indicating that for these cases it is not clear which optimization is most ideal. C1 USN, Res Lab, Div Oceanog, Stennis Space Ctr, MS 39529 USA. Univ Delaware, Ctr Appl Coast Res, Newark, DE 19716 USA. RP Kaihatu, JM (reprint author), USN, Res Lab, Div Oceanog, Code 7322, Stennis Space Ctr, MS 39529 USA. RI Kaihatu, James/H-7561-2016 OI Kaihatu, James/0000-0002-9277-6409 NR 30 TC 12 Z9 16 U1 0 U2 0 PU ASCE-AMER SOC CIVIL ENGINEERS PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 USA SN 0733-950X J9 J WATERW PORT C-ASCE JI J. Waterw. Port Coast. Ocean Eng.-ASCE PD MAR-APR PY 1998 VL 124 IS 2 BP 57 EP 67 DI 10.1061/(ASCE)0733-950X(1998)124:2(57) PG 11 WC Engineering, Civil; Engineering, Ocean; Water Resources SC Engineering; Water Resources GA YX294 UT WOS:000072025800003 ER PT J AU Thornton, EB Swayne, JL Dingler, JR AF Thornton, EB Swayne, JL Dingler, JR TI Small-scale morphology across the surf zone SO MARINE GEOLOGY LA English DT Article DE small-scale morphology; ripples; morphology; bedforms; nearshore bedforms; surf zone; waves and currents ID NEARSHORE; GEOMETRY AB Small-scale (<5 m horizontal length) nearshore morphologic height variations were measured by combining CRAB surveys with bed elevations acquired with a 1 MKz sonic altimeter mounted on the CRAB during the October Phase of the DUCK94 experiment. Bedform plan views were recorded simultaneously using a 500 kHz side-scan sonar mounted on the CRAB. Waves and currents were measured at the same time. Significant temporal and spatial variations in the small-scale morphology were measured in response to changing waves and currents during the 2 weeks examined. Three cases are examined in detail: (1) mild waves and weak longshore currents resulting in wave ripples throughout the study area; (2) storm waves with strong longshore currents resulting in lunate and straight-crested mega-ripples in the trough of the barred beach; and (3) narrow-band, normally incident waves with a strong rip current resulting in a planar bed except in the throat of the rip where mega-ripples were measured. Wavenumber spectra of the bed were generally broad, indicating newly formed ripples coexisted with residual ripples from the past to form complex, multi-scaled ripple patterns. (C) 1998 Elsevier Science B.V. C1 USN, Postgrad Sch, Dept Oceanog, Monterey, CA 93943 USA. US Geol Survey, Menlo Park, CA 94025 USA. RP Thornton, EB (reprint author), USN, Postgrad Sch, Dept Oceanog, Monterey, CA 93943 USA. NR 16 TC 31 Z9 31 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0025-3227 J9 MAR GEOL JI Mar. Geol. PD MAR PY 1998 VL 145 IS 3-4 BP 173 EP 196 DI 10.1016/S0025-3227(97)00114-X PG 24 WC Geosciences, Multidisciplinary; Oceanography SC Geology; Oceanography GA ZH755 UT WOS:000073144400002 ER PT J AU Shifler, DA AF Shifler, DA TI Flow-influenced corrosion in a waste energy sparge line SO MATERIALS PERFORMANCE LA English DT Article AB An inclined section of a carbon steel sparge line (I-in. [2.5 cm] outside diameter) with intermittent flow (similar to 10-s cycles) from a land-based steam boiler system had suffered failure after only 18 months in service. The area of failure occurred near the line's outlet to a 4-in. (10-cm) condensate collection line. The sparge line had severe, jagged pitting along the upper half of the steamside surface near the 4-in. line. There were wall perforations near the sparge line/collection line joint, with pitting gradually decreasing over a 1-ft (30-cm) distance away from the joint. This article discusses the failure evaluation and possible methods to contain the condition. C1 Naval Surface Warfare Ctr, Carderock Div, Corros Branch, W Bethesda, MD 20817 USA. RP Shifler, DA (reprint author), Naval Surface Warfare Ctr, Carderock Div, Corros Branch, Code 613,9500 MacArthur Blvd, W Bethesda, MD 20817 USA. NR 24 TC 0 Z9 0 U1 0 U2 0 PU NATL ASSN CORROSION ENG PI HOUSTON PA 1440 SOUTH CREEK DRIVE, HOUSTON, TX 77084-4906 USA SN 0094-1492 J9 MATER PERFORMANCE JI Mater. Perform. PD MAR PY 1998 VL 37 IS 3 BP 38 EP 44 PG 7 WC Materials Science, Characterization & Testing SC Materials Science GA ZA586 UT WOS:000072379400013 ER PT J AU Geltmacher, AB Koss, DA Stout, MG Matic, P AF Geltmacher, AB Koss, DA Stout, MG Matic, P TI Flow localization in sheet specimens with pairs of holes SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article ID DUCTILE FRACTURE AB The deformation localization behavior of sheet specimens containing geometric perturbations in the form of pairs of through-thickness holes is examined. Both experiments and computational modeling are performed in either uniaxial or equal-biaxial tension in order to examine the effect of applied loading path on the far-field strain needed to initiate localized necking in the ligament between the hole pairs, The models also examine the influence of hole spacing and matrix strain hardening on ligament localization. The far-field strain needed to cause the localization of the ligament is shown to increase as the biaxiality of the loading path increases, the hole spacing increases, and the strain-hardening exponent increases. The present study also indicates that the onset of localized necking can be predicted by employing the Hill criterion, if the local strain states within the ligament are taken into account. C1 Penn State Univ, Dept Met Sci & Engn, University Pk, PA 16802 USA. USN, Res Lab, Mech Mat Dept, Washington, DC 20375 USA. RP Geltmacher, AB (reprint author), Penn State Univ, Dept Met Sci & Engn, University Pk, PA 16802 USA. NR 10 TC 5 Z9 5 U1 0 U2 2 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 MAR PY 1998 VL 29 IS 3 BP 775 EP 780 DI 10.1007/s11661-998-0268-x PG 6 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA ZE391 UT WOS:000072787900007 ER PT J AU Ham, DW Pitman, KT Lassen, LF AF Ham, DW Pitman, KT Lassen, LF TI Fibrous dysplasia of the clivus and sphenoid sinus SO MILITARY MEDICINE LA English DT Article AB Fibrous dysplasia is a primary disease of bone that may lead to bony distortion, expansion, and weakness, Craniofacial involvement is an important entity for physicians to be aware of because of the potential for impingement on neurovascular structures, intracranial extension, and cosmetic deformity, We report two cases of craniofacial fibrous dysplasia and discuss the clinical presentation, radiographic and histologic findings, and the management of affected patients. C1 USN, Med Ctr, Dept Otolaryngol Head & Neck Surg, Portsmouth, VA 23708 USA. RP Ham, DW (reprint author), USN, Med Ctr, Dept Otolaryngol Head & Neck Surg, Portsmouth, VA 23708 USA. NR 14 TC 13 Z9 13 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 MAR PY 1998 VL 163 IS 3 BP 186 EP 189 PG 4 WC Medicine, General & Internal SC General & Internal Medicine GA ZA537 UT WOS:000072374300015 PM 9542863 ER PT J AU Guertin, NH Miller, RW AF Guertin, NH Miller, RW TI A-RCI - The right way to submarine superiority SO NAVAL ENGINEERS JOURNAL LA English DT Article AB Over the last ten years, there have been enormous changes in the fundamental factors that influence the development and procurement of submarine sonar systems. These changes can be summarized as: 1) the end of the Cold War; 2) a commercial sector technology revolution; and 3) Department of Defense (DoD) realizations that acquisition reforms were mandatory. Against this backdrop is the fact that the acoustic advantage held by U.S. submarines was being eroded by Russian nuclear submarine development and the proliferation of quiet non-nuclear submarines among countries of concern to the United States. A dramatic, innovative approach to reclaiming acoustic superiority had to be devised. The solution is the Acoustic Rapid COTS (Commercial-Off-the-Shelf) Insertion (A-RCI) program. A-RCI brings the benefits of the commercial processing revolution and DoD acquisition reforms to the submarine sonar system. It will provide a sonar system upgrade with far more capability than the existing systems have today at a fraction of their cost. This article provides a framework from which to view the significant leap that A-RCI provides to the Navy, and details both the programmatic and technical sides of the program to help the reader understand the impact A-RCI will have on the operating forces. C1 Naval Undersea Warfare Ctr, Div Newport, A RCI Program, Newport, RI 02840 USA. RP Guertin, NH (reprint author), Naval Undersea Warfare Ctr, Div Newport, A RCI Program, Newport, RI 02840 USA. NR 3 TC 0 Z9 0 U1 1 U2 2 PU AMER SOC NAVAL ENG INC PI ALEXANDRIA PA 1452 DUKE STREET, ALEXANDRIA, VA 22314-3458 USA SN 0028-1425 J9 NAV ENG J JI Nav. Eng. J. PD MAR PY 1998 VL 110 IS 2 BP 21 EP 33 PG 13 WC Engineering, Marine; Engineering, Civil; Oceanography SC Engineering; Oceanography GA ZL388 UT WOS:000073427900005 ER PT J AU Holden, RA Thomas, RW AF Holden, RA Thomas, RW TI Time-domain characteristics of complex computer networks SO NAVAL ENGINEERS JOURNAL LA English DT Article AB This paper presents a nontraditional use of statistical analysis methods to gain new insight in understanding complex systems. The properties of computer networks described here have implications in terms of the design, construction, and management of systems. An empirical approach is used to construct a covariance matrix that is a mathematical system which represents the real physical network. Some of the general physical properties of networks are deduced from the mathematical properties of covariance matrices. A network coupling coefficient is defined, and partitioning is described in terms of component variance and internal network processes that are shown to depend on data sample time, thus leading to time-domain behavior. Extensive illustrations are given using data taken from a combat system computer network. Also provided is a discussion of the practical application and meaning of the time-domain approach reported here. C1 USN, Ctr Surface Warfare, Dahlgren Div, Dahlgren, VA 22448 USA. RP Holden, RA (reprint author), USN, Ctr Surface Warfare, Dahlgren Div, Dahlgren, VA 22448 USA. NR 3 TC 1 Z9 1 U1 0 U2 0 PU AMER SOC NAVAL ENG INC PI ALEXANDRIA PA 1452 DUKE STREET, ALEXANDRIA, VA 22314-3458 USA SN 0028-1425 J9 NAV ENG J JI Nav. Eng. J. PD MAR PY 1998 VL 110 IS 2 BP 61 EP 72 PG 12 WC Engineering, Marine; Engineering, Civil; Oceanography SC Engineering; Oceanography GA ZL388 UT WOS:000073427900008 ER PT J AU Hansen, IS Wegner, DM AF Hansen, IS Wegner, DM TI Centenary of the destruction of USS Maine - A technical and historical review SO NAVAL ENGINEERS JOURNAL LA English DT Article AB The USS Maine exploded in Havana harbor on February 15, 1898 with the loss of 266 lives. Its loss sparked the battle cry "Remember the Maine," it became one of the causes of the Spanish-American War, and the ship and the event now symbolize an era. The ship has grabbed the public's interest and fascination for one hundred years, in large part due to the perceived mystery surrounding the cause of the disaster. The official investigations at the time blamed a mine, but this was not universally accepted. Lingering doubts resulted in much speculation without putting the "riddle" to rest. Admiral Hyman Rick-over became interested and assembled a team to see what could be determined from the original evidence when modern knowledge of explosion damage was applied. The results, which were published in his book of 1976, dispelled the main part of the mystery-there was no mine. A new foreword and a new addendum to the technical appendix of the book were provided by the authors of this article when a new edition was published in 1995. The verdict is still the same. Among several magazine articles occasioned by the centenary of the disaster, the National Geographic Magazine reports on the result of a new study they commissioned. That study maintains that the "riddle" still persists. This article summarizes the historical background and the technical factors which lead to the conclusion that a mine did not cause the destruction of the Maine. C1 NSWC, Carderock Div, Protect & Weap Effects Dept, Carderock, MD 20817 USA. NR 7 TC 1 Z9 1 U1 0 U2 1 PU AMER SOC NAVAL ENG INC PI ALEXANDRIA PA 1452 DUKE STREET, ALEXANDRIA, VA 22314-3458 USA SN 0028-1425 J9 NAV ENG J JI Nav. Eng. J. PD MAR PY 1998 VL 110 IS 2 BP 93 EP 104 PG 12 WC Engineering, Marine; Engineering, Civil; Oceanography SC Engineering; Oceanography GA ZL388 UT WOS:000073427900010 ER PT J AU Maclear, RD Connell, SH Doyle, BP Machi, IZ Butler, JE Sellschop, JPF Naidoo, SR Fritsch, E AF Maclear, RD Connell, SH Doyle, BP Machi, IZ Butler, JE Sellschop, JPF Naidoo, SR Fritsch, E TI Quantitative trace hydrogen distributions in natural diamond using 3D-micro-ERDA microscopy SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 13th International Conference on Ion Beam Analysis (IBA-13) CY JUL 27-AUG 01, 1997 CL LISBON, PORTUGAL AB A 3-D quantitative microscopy for minor distributions of surface and near-surface bulk hydrogen in solid samples has been developed. The technique employs a 15 MeV Si7+ microbeam and a two-dimensional position sensitive detector (2D PSD) with event reconstruction in an Elastic Recoil Detection Analysis (ERDA) geometry. Lateral resolutions of 10 mu m and depth resolutions of 300 Angstrom at an MDL of 100 ppm are currently possible. The technique is quantitative due to the use of an internal implanted spot standard or by cross calibration to an H implanted reference sample using RES as a normalisation transfer. Hydrogen content and configuration in diamond illuminates the genesis mechanism and environment. A hydrogen rich diamond exhibiting zoned cloud-like ensembles of micro-inclusions as well as smaller pockets of these inclusions has been interrogated for its near-surface-bulk hydrogen distribution. The sample has also been well characterised with optical microscopies and with bulk optical spectroscopies. A striking correlation between the hydrogen distribution and the optically visible inclusion have been obtained. This is the first direct evidence for aggregations of hydrogen associated with cloudy inclusions in natural hydrogen rich diamonds. (C) 1998 Elsevier Science B.V. C1 Univ Witwatersrand, Schonland Res Ctr Nucl Sci, ZA-2050 Wits, South Africa. USN, Res Lab, Div Chem, Gas Surface Dynam Sect, Washington, DC USA. Inst Mat Nantes, Lab Phys Cristalline Equipe, F-44322 Nantes, France. RP Maclear, RD (reprint author), Univ Witwatersrand, Schonland Res Ctr Nucl Sci, PO Wits, ZA-2050 Wits, South Africa. EM maclear@schonlan.src.wits.ac.za RI Butler, James/B-7965-2008; Connell, Simon/F-2962-2015 OI Butler, James/0000-0002-4794-7176; Connell, Simon/0000-0001-6000-7245 NR 7 TC 6 Z9 7 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-583X J9 NUCL INSTRUM METH B JI Nucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms PD MAR PY 1998 VL 136 BP 579 EP 582 DI 10.1016/S0168-583X(97)00701-5 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA ZW154 UT WOS:000074380400102 ER PT J AU Cormican, KJ Morton, DP Wood, RK AF Cormican, KJ Morton, DP Wood, RK TI Stochastic network interdiction SO OPERATIONS RESEARCH LA English DT Article ID LINEAR-PROGRAMS; RECOURSE; BOUNDS AB Using limited assets, an interdictor attempts to destroy parts of a capacitated network through which an adversary will subsequently maximize flow. We formulate and solve a stochastic version of the interdictor's problem: Minimize the expected maximum flow through the network when interdiction successes are binary random variables. Extensions are made to handle uncertain are capacities and other realistic variations. These two-stage stochastic integer programs have applications to interdicting illegal drugs and to reducing the effectiveness of a military force moving materiel, troops, information, etc., through a network in wartime. Two equivalent model formulations allow Jensen's inequality to be used to compute both lower and upper bounds on the objective, and these bounds are improved within a sequential approximation algorithm. Successful computational results are reported on networks with over 100 nodes, 80 interdictable arcs, and 180 total arcs. C1 USN, Postgrad Sch, Monterey, CA 93940 USA. Univ Texas, Dept Mech Engn, Operat Res Grp, Austin, TX 78712 USA. Stanford Univ, Dept Operat Res, Stanford, CA 94305 USA. RP Cormican, KJ (reprint author), USN, Postgrad Sch, Monterey, CA 93940 USA. RI Morton, David/K-2388-2014; OI Wood, Kevin/0000-0002-0311-8712 NR 32 TC 101 Z9 104 U1 0 U2 3 PU INST OPERATIONS RESEARCH MANAGEMENT SCIENCES PI LINTHICUM HTS PA 901 ELKRIDGE LANDING RD, STE 400, LINTHICUM HTS, MD 21090-2909 USA SN 0030-364X J9 OPER RES JI Oper. Res. PD MAR-APR PY 1998 VL 46 IS 2 BP 184 EP 197 DI 10.1287/opre.46.2.184 PG 14 WC Management; Operations Research & Management Science SC Business & Economics; Operations Research & Management Science GA 117CR UT WOS:000075763500003 ER PT J AU Schallhorn, SC Reid, JL Kaupp, SE Blanton, CL Zoback, L Goforth, H Flowers, CW McDonnell, PJ AF Schallhorn, SC Reid, JL Kaupp, SE Blanton, CL Zoback, L Goforth, H Flowers, CW McDonnell, PJ TI Topographic detection of photorefractive keratectomy SO OPHTHALMOLOGY LA English DT Article ID CORNEAL TOPOGRAPHY AB Purpose: This study aimed to evaluate the sensitivity and specificity of subjective review of corneal topography to detect patients who have undergone photorefractive keratectomy (PRK). Methods: Topographic maps from 3 different devices were obtained from 19 patients with postoperative PRK and 9 control subjects with emmetropia and 10 control subjects with myopia. Each image was printed in an absolute and relative scale (total of 228 maps) and graded for overall shape and pattern. Fifteen masked reviewers independently rated each map as either postoperative PRK or not. Results: The overall sensitivity (ability to detect PRK) and specificity rates (ability to exclude control subjects) by reviewers were 65% and 93%, respectively, Sensitivity was influenced independently by the scale (relative, 68%; absolute, 62%; P < 0.01), experience of reviewer (experienced, 77%; inexperienced, 53%; P < 0.001), and device (Alcon, 67 +/- 29.9; Eyesys, 75 +/- 29.4%; and Tomey, 54 +/- 31.7%; P < 0.001), Low levels of preoperative myopia were consistently more difficult to detect than higher levels (low myopia -1.50 to -2.99 diopters [D] sensitivity: 53 +/- 34.5%; medium level -3.00 to -4.49 D:67 +/- 28.9%; and high level -4.50 to -6.00 D:77 +/- 21.1%; P < 0.0001), Differences in specificity between experienced and inexperienced reviewers were obtained when maps had a homogeneous topographic pattern (97 +/- 5.6% and 85 +/- 13.7%, respectively; P < 0.05), Several control topography patterns (e.g., homogeneous, focal, and keyhole) were disproportionately more difficult to correctly identify on the Eyesys device. Conclusions: Topographic experience is a significant factor influencing the correct identification of PRK. Techniques also can be used to enhance detection, such as the use of different devices and scales, However, if subjective review of topography is used as the only method of detection, many patients with PRK will not be identified properly. In addition, the most prevalent preoperative myopic category in the general population (myopia < -3.00 D) also is the most difficult to detect after treatment, This reduces the usefulness of topography as a screening tool, Other techniques are needed to improve the detection of patients with postoperative PRK. C1 USN, Med Ctr, Dept Ophthalmol & Clin Invest, San Diego, CA 92134 USA. USN, Hlth Res Ctr, San Diego, CA 92152 USA. Inland Eye Inst, Colton, CA USA. Charles R Drew Univ Med & Sci, Los Angeles, CA 90059 USA. Doheny Eye Inst, Los Angeles, CA 90033 USA. RP Schallhorn, SC (reprint author), USN, Med Ctr, Dept Ophthalmol & Clin Invest, San Diego, CA 92134 USA. NR 14 TC 8 Z9 8 U1 0 U2 0 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 507 EP 516 DI 10.1016/S0161-6420(98)93035-4 PG 10 WC Ophthalmology SC Ophthalmology GA YZ385 UT WOS:000072249100038 PM 9499783 ER PT J AU Driggers, RG Cox, PG Leachtenauer, J Vollmerhausen, R Scribner, DA AF Driggers, RG Cox, PG Leachtenauer, J Vollmerhausen, R Scribner, DA TI Targeting and intelligence electro-optical recognition modeling: a juxtaposition of the probabilities of discrimination and the general image quality equation SO OPTICAL ENGINEERING LA English DT Article DE electro-optical; performance; infrared; target acquisition; minimum resolvable temperature, National Imagery Interpretability Scale, general image quality equation AB The recognition of objects using target acquisition systems is modeled by a sensor's minimum resolvable temperature (MRT), the Johnson criteria, atmospherics, and object specifics. Collectively, these three characteristics provide an acquisition model for estimating the probability of object recognition (and detection, identification) as a function of sensor-to-object range. This technique is called the probabilities of discrimination. When quantifying the performance of intelligence-surveillance-reconnaissance (ISR) systems, object recognition is assessed using the National Imagery Interpretability Scale (NIIRS). Each NIIRS level corresponds to a different capacity for object recognition and is defined by a set of recognition criteria. The general image quality equation (GIQE) is the ISR sensor model that determines the expected NIIRS level of a sensor for a given set of sensor parameters. It is important that electro-optical sensor engineers understand both of these recognition models. The segregation between the target acquisition and ISR sensor communities is becoming less sharp as ISR sensors are beginning to be used for target acquisition purposes and visa versa. Network and wireless communication advances are providing the means for dual exploitation of these systems. Descriptions of these two recognition models, probabilities of discrimination, and the GIQE are provided. The two models are applied to example systems. Finally, the two models are compared and contrasted. (C) 1998 Society of Photo-Optical Instrumentation Engineers.[S0091-3286(98)00503-0]. C1 USA, Commun & Elect Command, Night Vis & Elect Sensors Directorate, Ft Belvoir, VA 22060 USA. Sci Applicat Int Corp, Arlington, VA 22203 USA. ERIM Lab, Arlington, VA 22209 USA. USN, Res Lab, Div Opt Sci, Washington, DC 20375 USA. RP Driggers, RG (reprint author), USA, Commun & Elect Command, Night Vis & Elect Sensors Directorate, 10221 Burbeck Rd,Suite 430, Ft Belvoir, VA 22060 USA. NR 15 TC 20 Z9 20 U1 1 U2 8 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 789 EP 797 DI 10.1117/1.601911 PG 9 WC Optics SC Optics GA ZC007 UT WOS:000072530200009 ER PT J AU McBride, MT Hennrikus, WL Mologne, TS AF McBride, MT Hennrikus, WL Mologne, TS TI Newborn clavicle fractures SO ORTHOPEDICS LA English DT Article; Proceedings Paper CT 63rd Annual Meeting of the American-Academy-of-Orthopaedic-Surgeons CY FEB 22-27, 1996 CL ATLANTA, GEORGIA SP Amer Acad Orthopaed Surgeons ID BIRTH TRAUMA AB A prospective screening program of 9106 newborns identified 43 infants with clavicle fractures for a prevalence of 1 fracture in every 213 live births (0.5%). The fractures were equally distributed by right and left side involvement, and male and female sex. All fractures occurred during vaginal deliveries. None were breech presentation. Risk factors for fracture included large birthweight, shoulder dystocia, mechanically assisted delivery, and prolonged gestational age. One in 11 newborns with a clavicle fracture also had a brachial plexus palsy. C1 USN Hosp, Dept Orthoped Surg & Clin Invest, San Diego, CA 92134 USA. RP Hennrikus, WL (reprint author), Valley Childrens Hosp, Dept Orthoped, 3151 N Millbrook Ave, Fresno, CA 93703 USA. NR 18 TC 8 Z9 8 U1 0 U2 0 PU SLACK INC PI THOROFARE PA 6900 GROVE RD, THOROFARE, NJ 08086 USA SN 0147-7447 J9 ORTHOPEDICS JI Orthopedics PD MAR PY 1998 VL 21 IS 3 BP 317 EP 320 PG 4 WC Orthopedics SC Orthopedics GA ZE371 UT WOS:000072785900013 PM 9547816 ER PT J AU Menon, ESK Fox, AG AF Menon, ESK Fox, AG TI Debye-Waller factors of stoichiometric and Al-rich gamma-TiAl alloys SO PHILOSOPHICAL MAGAZINE A-PHYSICS OF CONDENSED MATTER STRUCTURE DEFECTS AND MECHANICAL PROPERTIES LA English DT Article ID BONDING CHARGE-DENSITY; MEAN-SQUARE DISPLACEMENTS; ELECTRON-DIFFRACTION AB Average room temperature Debye-Waller factors (B) over bar and individual (isotropic) temperature factors B-Ti and B-Al of gamma-TiAl alloys containing 51, 54 and 56 at.% Al have been determined by conventional powder X-ray diffraction. The (B) over bar values for Ti-50at.%Al and Ti-56at.%Al were also measured by the critical voltage method in electron diffraction. The temperature factors were calculated from the X-ray intensities using both free-atom relativistic Hartree-Fock structure factors as well as a set of structure factors obtained from first principles local density calculations for the equiatomic gamma-TiAl alloy. The (B) over bar values determined from the X-ray intensities using the free-atom structure factors were found to be in poor agreement with those determined by electron diffraction whereas the (B) over bar values calculated from the X-ray intensities using structure factors obtained from first-principles calculations were found to be in good agreement with the electron diffraction data. This difference appears to arise because many of the low-angle structure factors of gamma-TiAl (up to hkl = 224) are significantly different from the free-atom values owing to crystal bonding. It was found to be difficult to determine the individual temperature factors B-Ti and B-Al With high accuracy, particularly for the 54 and 56at.%Al alloys. This is ascribed to the static contributions to the Debye-Waller factors associated with the excess Al atoms on Ti sites and to the ordering of these excess Al atoms on the Ti sublattice as discussed in recent single-crystal X-ray work on this topic. C1 USN, Postgrad Sch, Ctr Mat Sci & Engn, Monterey, CA 93943 USA. RP Menon, ESK (reprint author), USN, Postgrad Sch, Ctr Mat Sci & Engn, Monterey, CA 93943 USA. NR 29 TC 5 Z9 5 U1 1 U2 3 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON EC4A 3DE, ENGLAND SN 0141-8610 J9 PHILOS MAG A JI Philos. Mag. A-Phys. Condens. Matter Struct. Defect Mech. Prop. PD MAR PY 1998 VL 77 IS 3 BP 577 EP 592 PG 16 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Physics, Applied; Physics, Condensed Matter SC Materials Science; Metallurgy & Metallurgical Engineering; Physics GA YZ239 UT WOS:000072234200003 ER PT J AU Chakarian, V Idzerda, YU Chen, CT AF Chakarian, V Idzerda, YU Chen, CT TI Absolute helicity-dependent photoabsorption cross sections of Fe thin films and quantitative evaluation of magnetic-moment determination SO PHYSICAL REVIEW B LA English DT Article ID RAY CIRCULAR-DICHROISM; SUM-RULES; ABSORPTION; NI; TRANSMISSION; EDGES; METALS; CO AB Energy and helicity-dependent absolute photoabsorption cross sections at the Fe L-2,L-3 edge, measured in transmission from a supported ultrathin Fe film, are presented. These cross sections and semiempirical total-electron-yield (TEY) equations are used to show that the effects of saturation/self-absorption in the TEY spectra, as reflected in the quantitative evaluation of magnetic moments, can be quite severe. These conclusions are confirmed by directly comparing the data obtained simultaneously by TEY and transmission. C1 USN, Res Lab, Washington, DC 20375 USA. AT&T Bell Labs, Murray Hill, NJ 07974 USA. RP Chakarian, V (reprint author), Brookhaven Natl Lab, Bldg 510E, Upton, NY 11973 USA. NR 23 TC 52 Z9 52 U1 0 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 1 PY 1998 VL 57 IS 9 BP 5312 EP 5315 DI 10.1103/PhysRevB.57.5312 PG 4 WC Physics, Condensed Matter SC Physics GA ZA389 UT WOS:000072358600063 ER PT J AU Geer, RE Singer, SJ Selinger, JV Ratna, BR Shashidhar, R AF Geer, RE Singer, SJ Selinger, JV Ratna, BR Shashidhar, R TI Electric-field-induced layer buckling in chiral smectic-A liquid crystals SO PHYSICAL REVIEW E LA English DT Article ID INSTABILITIES; EVOLUTION; DISORDER; PATTERNS; TEXTURE; CELLS AB X-ray-scattering data from chiral smectic-A liquid crystals under an applied electric field have been analyzed to investigate the layer-buckling instability. A quantitative description of the scattering data at all values of the field is obtained via calculation of the minimal-energy layer displacement profiles determined from the continuum smectic free energy. From this analysis the real-space layer-buckling profiles are determined, revealing a sinusoid to soliton evolution with increasing field. C1 Ohio State Univ, Dept Chem, Columbus, OH 43210 USA. USN, Res Lab, Ctr Biomol Sci & Engn, Washington, DC 20375 USA. RP Geer, RE (reprint author), SUNY Albany, Dept Phys, Albany, NY 12222 USA. RI Selinger, Jonathan/D-1445-2010; Singer, Sherwin/G-8424-2015 OI Selinger, Jonathan/0000-0002-4982-2457; Singer, Sherwin/0000-0002-4539-5742 NR 16 TC 32 Z9 32 U1 0 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD MAR PY 1998 VL 57 IS 3 BP 3059 EP 3062 DI 10.1103/PhysRevE.57.3059 PN A PG 4 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA ZD003 UT WOS:000072641100071 ER PT J AU Colombant, D Klapisch, M Bar-Shalom, A AF Colombant, D Klapisch, M Bar-Shalom, A TI Increase in Rosseland mean opacity for inertial fusion hohlraum walls SO PHYSICAL REVIEW E LA English DT Article ID PLASMA; MODEL; HOT AB The Rosseland mean opacity of hohlraum gold walls can be increased by filling in the low absorption gaps in the gold spectrum with one or more additional elements. Using our opacity code STA, we investigated various mixtures. A combination of gold and copper, or nickel, is equivalent or better than the previously proposed gold and gadolinium mixture, and is much easier to fabricate. Other more elaborate mixtures yield even higher opacities. Our simulations are in good agreement with experiment. At the temperatures and densities of interest, non-local-thermodynamic-equilibrium corrections are minor, of order 10%, and not significant in view of the experimental accuracy. C1 USN, Div Plasma Phys, Res Lab, Washington, DC 20375 USA. ARTEP Inc, Columbia, MD 21045 USA. NRCN, Beer Sheva, Israel. RP Colombant, D (reprint author), USN, Div Plasma Phys, Res Lab, Washington, DC 20375 USA. NR 15 TC 40 Z9 47 U1 2 U2 4 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1539-3755 J9 PHYS REV E JI Phys. Rev. E PD MAR PY 1998 VL 57 IS 3 BP 3411 EP 3416 DI 10.1103/PhysRevE.57.3411 PN B PG 6 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA ZD006 UT WOS:000072641400039 ER PT J AU Wentworth, M Wentworth, A AF Wentworth, M Wentworth, A TI Hamstring muscle stretching SO PHYSICAL THERAPY LA English DT Letter C1 USN Hosp, Jacksonville, FL 32214 USA. RP Wentworth, M (reprint author), USN Hosp, 2080 Child St, Jacksonville, FL 32214 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER PHYSICAL THERAPY ASSOC PI ALEXANDRIA PA 1111 N FAIRFAX ST, ALEXANDRIA, VA 22314 USA SN 0031-9023 J9 PHYS THER JI Phys. Ther. PD MAR PY 1998 VL 78 IS 3 BP 321 EP 321 PG 1 WC Orthopedics; Rehabilitation SC Orthopedics; Rehabilitation GA ZE826 UT WOS:000072835500011 PM 9520977 ER PT J AU McKeown, DA Bell, MI AF McKeown, DA Bell, MI TI Linked four-membered silicate rings: vibrational analysis of Gillespite. BaFeSi4O10 and implications for glass structure SO PHYSICS AND CHEMISTRY OF MINERALS LA English DT Article ID BENITOITE BATISI3O9; RAMAN-SPECTROSCOPY AB Raman spectra and lattice dynamics calculations are presented for the silicate mineral gillespite, BaFeSi4O10, which contains sheets of linked four-membered silicate rings. The results are analyzed in relation to earlier work done on the isolated four-membered ring silicate BaCuSi2O6 and to published claims that vibrational modes of four-membered rings are responsible for the sharp D-1 "defect line" observed in the Raman spectra of SiO2 glass. The crystal structure of gillespite (space group P4/ncc or D-4h(8)) consists of puckered Si4O12 rings, where each SiO4 tetrahedron is linked to two neighboring tetrahedra within a ring and to a third tetrahedron within a different ring. The rings are linked to each other in a staggered configuration to form sheets, which are also bonded together by Ba2+ and Fe2+. The calculation adjusts the bond bending and bond stretching force constants so that calculated fundamental mode frequencies best fit observed fundamental frequencies in the Raman spectra; eigenmodes associated with each calculated fundamental mode are then generated. Some eigenmodes calculated are unique to the gillespite structure, but many of the more localized four-membered ring modes are similar to those calculated for the four-membered rings in BaCuSi2O6 and for the three-and six-membered rings in the cyclosilicates studied earlier. The results for gillespite indicate that the Raman-active A(1g) mode at 450 cm(-1) is a four-membered ring bridging oxygen breathing mode that is mixed with other minor ring deformation displacements; because of this mixing, the calculated frequency of this mode is 45 to 61 cm(-1) lower than that calculated for bridging oxygen binding breathing modes of puckered four-membered rings in BaCuSi2O6 and in simulated glass structures. C1 Howard Univ, Dept Chem, Washington, DC 20059 USA. USN, Res Lab, Dynam Solids Branch, Washington, DC 20375 USA. RP McKeown, DA (reprint author), Catholic Univ Amer, Vitreous State Lab, 620 Michigan Ave NE, Washington, DC 20064 USA. NR 14 TC 8 Z9 8 U1 3 U2 11 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0342-1791 J9 PHYS CHEM MINER JI Phys. Chem. Miner. PD MAR PY 1998 VL 25 IS 4 BP 273 EP 281 DI 10.1007/s002690050114 PG 9 WC Materials Science, Multidisciplinary; Mineralogy SC Materials Science; Mineralogy GA ZF508 UT WOS:000072904500004 ER PT J AU Uhm, HS AF Uhm, HS TI Control of plasma sheath and its potential by dielectric medium SO PHYSICS OF PLASMAS LA English DT Article AB Influence of a dielectric medium on the properties of plasma sheaths is investigated. A theoretical model is developed under the assumption that collisionless plasma is confined by two planar electrodes. A planar dielectric medium with a finite thickness is inserted into the plasma, partitioning it into two pieces. Without a priori assumption about the plasma density, an analytical expression of potential distribution in the plasma-dielectric system is obtained. It is found that the electric potential at the dielectric center in high-density plasma is independent of its position and is a half-value of the applied voltage. The electric potential, field, and the charge density in high-density plasma are inversely proportional to the sum of 4+D/epsilon lambda, where D and epsilon are the thickness and dielectric constant, respectively, of the dielectric medium, and lambda is the Debye length of high-density plasmas. In this context, the plasma sheaths may easily be controlled by an appropriate choice of dielectric material and its size. C1 USN, Ctr Surface Warfare, Carderock Div, W Bethesda, MD 20817 USA. RP Uhm, HS (reprint author), USN, Ctr Surface Warfare, Carderock Div, 9500 MacArthur Blvd, W Bethesda, MD 20817 USA. NR 2 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 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD MAR PY 1998 VL 5 IS 3 BP 818 EP 824 DI 10.1063/1.872769 PG 7 WC Physics, Fluids & Plasmas SC Physics GA ZA377 UT WOS:000072357400033 ER PT J AU Soulen, RJ Fogle, WE AF Soulen, RJ Fogle, WE TI Author's expressions change in reaction to superfluidity glitches SO PHYSICS TODAY LA English DT Letter C1 USN, Res Lab, Washington, DC 20375 USA. Lawrence Berkeley Lab, Berkeley, CA USA. RP Soulen, RJ (reprint author), USN, Res Lab, Washington, DC 20375 USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0031-9228 J9 PHYS TODAY JI Phys. Today PD MAR PY 1998 VL 51 IS 3 BP 117 EP 117 DI 10.1063/1.882171 PG 1 WC Physics, Multidisciplinary SC Physics GA ZA380 UT WOS:000072357700028 ER PT J AU Koch, JA Landen, OL Hammel, BA Seely, J Barbee, TW Bennett, G Brown, C Celliers, P Da Silva, LB Glendinning, SG Hsing, W Kalantar, DH AF Koch, JA Landen, OL Hammel, BA Seely, J Barbee, TW Bennett, G Brown, C Celliers, P Da Silva, LB Glendinning, SG Hsing, W Kalantar, DH TI High-energy X-ray microscopy of laser-fusion plasmas at the National Ignition Facility SO PLASMA PHYSICS REPORTS LA English DT Article AB Multi-keV X-ray microscopy will be an important laser-produced plasma diagnostic at future megajoule facilities such as the National Ignition Facility (NIF). In preparation for the construction of this facility, we have investigated several instrumentation options in detail, and we conclude that near-normal-incidence single spherical or toroidal crystals may offer the best general solution for high-energy X-ray microscopy at NIF and at similar large facilities. Kirkpatrick-Baez microscopes using multilayer mirrors may also be good secondary options, particularly if apertures are used to increase the band width-limited field of view. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. USN, Res Lab, Washington, DC 20375 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Koch, JA (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,L-473, Livermore, CA 94550 USA. NR 10 TC 0 Z9 0 U1 1 U2 3 PU MAIK NAUKA/INTERPERIODICA PUBL PI WOODBURY PA C/O AMERICAN INST PHYSICS, 500 SUNNYSIDE BLVD, MEMBER SUBSCRIBER SERVICES, WOODBURY, NY 11797-2999 USA SN 1063-780X J9 PLASMA PHYS REP JI Plasma Phys. Rep. PD MAR PY 1998 VL 24 IS 3 BP 177 EP 179 PG 3 WC Physics, Fluids & Plasmas SC Physics GA ZF061 UT WOS:000072858800002 ER PT J AU Wirtz, JJ AF Wirtz, JJ TI Tonkin Gulf and the escalation of the Vietnam war SO POLITICAL SCIENCE QUARTERLY LA English DT Book Review C1 USN, Postgrad Sch, Monterey, CA 93943 USA. RP Wirtz, JJ (reprint author), USN, Postgrad Sch, Monterey, CA 93943 USA. NR 1 TC 0 Z9 0 U1 0 U2 3 PU ACAD POLITICAL SCIENCE PI NEW YORK PA 475 RIVERSIDE DRIVE, SUITE 1274, NEW YORK, NY 10115-1274 USA SN 0032-3195 J9 POLIT SCI QUART JI Polit. Sci. Q. PD SPR PY 1998 VL 113 IS 1 BP 145 EP 146 DI 10.2307/2657664 PG 2 WC Political Science SC Government & Law GA ZK626 UT WOS:000073344000017 ER PT J AU Stephens, MB Pepper, PV AF Stephens, MB Pepper, PV TI Streptokinase therapy - Recognizing and treating allergic reactions SO POSTGRADUATE MEDICINE LA English DT Article ID ACUTE MYOCARDIAL-INFARCTION AB Streptokinase is an important component in the treatment strategy for acute myocardial infarction. However, physicians need to be aware that some patients may experience allergic reactions to this drug. Prompt recognition and appropriate management of symptoms usually result in recovery from the allergic event without further complication. PGM. C1 USN, Med Ctr, Primary Care Grp, San Diego, CA 92106 USA. RP Stephens, MB (reprint author), USN, Med Ctr, Primary Care Grp, 2650 Stockton Rd, San Diego, CA 92106 USA. EM stephens@snd10.med.navy.mil RI Stephens, Mark/A-2679-2015 NR 8 TC 3 Z9 3 U1 0 U2 1 PU MCGRAW HILL HEALTHCARE PUBLICATIONS PI MINNEAPOLIS PA 4530 WEST 77TH ST, MINNEAPOLIS, MN 55435-5000 USA SN 0032-5481 J9 POSTGRAD MED JI Postgrad. Med. PD MAR PY 1998 VL 103 IS 3 BP 89 EP 90 PG 2 WC Medicine, General & Internal SC General & Internal Medicine GA ZB003 UT WOS:000072425100014 PM 9519032 ER PT J AU Nash, WP AF Nash, WP TI Information gating: An evolutionary model of personality function and dysfunction SO PSYCHIATRY-INTERPERSONAL AND BIOLOGICAL PROCESSES LA English DT Article ID FACIAL EXPRESSIONS; EMPATHY; DISORDERS; EMOTION; PSYCHOPATHOLOGY; PSYCHOTHERAPY; TEMPERAMENT; PERSPECTIVE; PSYCHOLOGY; INTENSITY AB UTILIZING principles of evolutionary biology, a model is developed which defines the essential adaptive functions of personality as a whole, and describes how failure in those functions produces the maladaptations characteristic of personality disorders. In this model, personality is hypothesized to have evolved specifically to make human culture possible by managing the flow of information within the culture, especially by mediating teaching and learning, competition and cooperation, and leading and following. These essential culture-forming capacities of personality have at their root the more basic function of information gating, which is defined here as the continuous regulation by personality of its openness for the bidirectional flow of sensory, cognitive, emotional, and motor information between internal self and external social systems, to best meet the needs of both in various situations. The maladaptations characteristic of personality disorders are postulated to be due to their being chronically and frequently too open or too closed for expressing or assimilating social information, given their circumstances. The relationship of this model to other evolutionary models of personality is discussed, as are its clinical and research implications. C1 USN, Med Ctr, Dept Psychiat, San Diego, CA 92134 USA. RP Nash, WP (reprint author), USN, Med Ctr, Dept Psychiat, San Diego, CA 92134 USA. NR 57 TC 1 Z9 1 U1 1 U2 3 PU GUILFORD PUBLICATIONS INC PI NEW YORK PA 72 SPRING STREET, NEW YORK, NY 10012 USA SN 0033-2747 J9 PSYCHIATRY JI Psychiatry-Interpers. Biol. Process. PD SPR PY 1998 VL 61 IS 1 BP 46 EP 60 PG 15 WC Psychiatry SC Psychiatry GA ZM226 UT WOS:000073517300005 PM 9595595 ER PT J AU Hyams, KC AF Hyams, KC TI Lessons derived from evaluating Gulf War syndrome: Suggested guidelines for investigating possible outbreaks of new diseases SO PSYCHOSOMATIC MEDICINE LA English DT Editorial Material ID CHRONIC FATIGUE SYNDROME; SYMPTOMS C1 USN, Med Res Inst, Div Epidemiol, Bethesda, MD 20889 USA. RP Hyams, KC (reprint author), USN, Med Res Inst, Div Epidemiol, 8901 Wisconsin Ave, Bethesda, MD 20889 USA. NR 17 TC 3 Z9 3 U1 1 U2 1 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 USA SN 0033-3174 J9 PSYCHOSOM MED JI Psychosom. Med. PD MAR-APR PY 1998 VL 60 IS 2 BP 137 EP 139 PG 3 WC Psychiatry; Psychology; Psychology, Multidisciplinary SC Psychiatry; Psychology GA ZE098 UT WOS:000072757500001 PM 9560859 ER PT J AU Stroup, MD AF Stroup, MD TI Some evidence of congressional political markets in DOD personnel allocations across states SO PUBLIC CHOICE LA English DT Article AB An empirical analysis of the distribution of Department of Defense (DOD) personnel (both military and civilian) across states is developed with a commonly used Public Choice model of resource allocation in a legislative setting. The model specification employs Congressional seniority, Congressional committee representation, Presidential electoral votes, and the per capita dollar value of prime defense contract awards to explain the variation of DOD personnel across states over time. The empirical analysis is performed over the last three decades, and the results indicate that this particular Public Choice legislative model performs well in explaining the variation in DOD personnel allocations across states. The results also provide some limited evidence of a possible political market between the states for DOD personnel allocations. This analysis has implications for future testing of whether the Base Realignment and Closure Commission (established in 1988 under President Reagan), and the Defense Base Closure and Realignment Commission of 1990 (under President Bush) were effective in significantly decreasing the legislative politics involved in the selection and approval process for base closure and realignment. C1 USN, Postgrad Sch, DRMI, Monterey, CA 93943 USA. RP Stroup, MD (reprint author), USN, Postgrad Sch, DRMI, 1522 Cunningham Rd, Monterey, CA 93943 USA. NR 14 TC 0 Z9 0 U1 0 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0048-5829 J9 PUBLIC CHOICE JI Public Choice PD MAR PY 1998 VL 94 IS 3-4 BP 241 EP 254 DI 10.1023/A:1017923420545 PG 14 WC Economics; Political Science SC Business & Economics; Government & Law GA ZF169 UT WOS:000072870600002 ER PT J AU Mokole, EL Choudhury, AK Samaddar, SN AF Mokole, EL Choudhury, AK Samaddar, SN TI Transient radiation from thin, half-wave, orthogonal dipoles SO RADIO SCIENCE LA English DT Article ID ANTENNA AB The intent of this work is to ascertain through analytical means whether a circularly polarized radiated field is possible for some antenna configuration with an ultrawideband (UWB) source. Consequently, the behavior of the radiated electric field from identical, thin, half-wave, electromagnetically uncoupled, orthogonal dipoles in free space that are excited by a finite-duration UWB voltage is studied. The zero-order approximate solution for the current distribution along a dipole is used to permit easy calculation and interpretation of the time domain current and radiated far field. The far field is derived, and this result is applied to a finite-cycle-sine input (L cycles) to each dipole, where the carrier frequency f(0) corresponds to the dipoles' common length and the inputs are separated in time by 0.25/f(0). When the dipoles and the feed network are perfectly matched and the observation direction is broadside, the time domain field is extended in time to (L + 0.75)/f(0) with respect to the duration of the source Lifo, and circular polarization occurs for (L - 0.75)/f(0). For the UWB case (L = 1), the radiated field's duration is 1.75 times the duration of the source, and circular polarization occurs only for one quarter of the period of the source. When the dipoles and the feed network are not matched exactly, the field's duration is infinite, and circular polarization never occurs in the strict sense. However, if the feed network and the dipoles are approximately matched, the field is negligible after a time, and nearly circular polarization occurs. C1 USN, Res Lab, Div Radar, Washington, DC 20375 USA. Howard Univ, Dept Elect Engn, Washington, DC 20059 USA. RP Mokole, EL (reprint author), USN, Res Lab, Div Radar, Code 5341, Washington, DC 20375 USA. NR 10 TC 2 Z9 2 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0048-6604 J9 RADIO SCI JI Radio Sci. PD MAR-APR PY 1998 VL 33 IS 2 BP 219 EP 229 DI 10.1029/98RS00126 PG 11 WC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Remote Sensing; Telecommunications SC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Remote Sensing; Telecommunications GA ZE395 UT WOS:000072788300003 ER PT J AU Raphael, MP Reeves, ME Skelton, EF AF Raphael, MP Reeves, ME Skelton, EF TI Nonlinear response of type II superconductors: A new method of measuring the pressure dependence of the transition temperature T-c(P) SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID HARMONIC SUSCEPTIBILITIES; MAGNETIC RESPONSE AB A technique of measuring T-c(P) in the diamond anvil cell try the third harmonic of the ac susceptibility (V-3f) is described. It requires no background subtraction and allows the use of gasket materials made from hardened steels. In addition, the observed peak structure in the V-3f VS T data allows regions with different critical temperatures to be distinguished. Results for single crystals (with typical size, 0.25 mmX0.25 mmx0.1 mm) of the Tl2Ba2CuO6+delta and YBa2Cu3O7-delta systems are presented. The effects of sample inhomogeneities and nonhydrostatic conditions are discussed. (C) 1998 American Institute of Physics. C1 Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. George Washington Univ, Dept Phys, Washington, DC 20052 USA. USN, Res Lab, Washington, DC 20375 USA. RP Reeves, ME (reprint author), Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. EM reevesme@gwis2.circ.gwu.edu NR 18 TC 6 Z9 7 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD MAR PY 1998 VL 69 IS 3 BP 1451 EP 1455 DI 10.1063/1.1148780 PG 5 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA ZC403 UT WOS:000072574500045 ER PT J AU Hyde, BD AF Hyde, BD TI SandyDuck 97: 'Lost our way'? SO SEA TECHNOLOGY LA English DT Letter C1 USN, Tenants Harbor, ME USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU COMPASS PUBL INC PI ARLINGTON PA SUITE 1000 1117 N 19 ST, ARLINGTON, VA 22209 USA SN 0093-3651 J9 SEA TECHNOL JI Sea Technol. PD MAR PY 1998 VL 39 IS 3 BP 87 EP 87 PG 1 WC Engineering, Ocean SC Engineering GA ZC606 UT WOS:000072598300011 ER PT J AU O'Leary, SK Foutz, BE Shur, MS Bhapkar, UV Eastman, LF AF O'Leary, SK Foutz, BE Shur, MS Bhapkar, UV Eastman, LF TI Monte Carlo simulation of electron transport in wurtzite aluminum nitride SO SOLID STATE COMMUNICATIONS LA English DT Article DE semiconductors; electronic transport ID GALLIUM NITRIDE; VELOCITY; GAN; SEMICONDUCTORS; MOBILITY; GAAS AB We present the steady-state, velocity-field characteristics of wurtzite aluminum nitride, determined using an ensemble Monte Carlo approach. A three valley model for the conduction band is employed and ionized impurity, polar optical phonon, piezoelectric, deformation potential and intervalley scattering mechanisms are considered. We find that aluminum nitride exhibits peak and saturation drift velocities of 1.7 x 10(7) cm s(-1) and 1.4 x 10(7) cm s(-1), respectively, at a temperature of 300 K and a doping concentration of 1.0 x 10(17) cm(-3). The sensitivity of these steady-state results to variations in temperature and doping concentration is examined and is found to be much less than that of gallium arsenide. We also explore the sensitivity of our results to variations in the piezoelectric constant and demonstrate that piezoelectric scattering plays a significant role in determining the form of the wurtzite aluminum nitride velocity-field characteristic. (C) 1998 Elsevier Science Ltd. C1 Rensselaer Polytech Inst, Dept Elect Comp & Syst Engn, Troy, NY 12180 USA. Cornell Univ, Sch Elect Engn, Ithaca, NY 14853 USA. USN, Ctr Surface Warfare, Dahlgren, VA 22448 USA. RP O'Leary, SK (reprint author), Rensselaer Polytech Inst, Dept Elect Comp & Syst Engn, Troy, NY 12180 USA. RI Shur, Michael/A-4374-2016 OI Shur, Michael/0000-0003-0976-6232 NR 31 TC 55 Z9 61 U1 1 U2 4 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 MAR PY 1998 VL 105 IS 10 BP 621 EP 626 DI 10.1016/S0038-1098(97)10207-1 PG 6 WC Physics, Condensed Matter SC Physics GA YX125 UT WOS:000072008900003 ER PT J AU Guha, S Leppert, VJ Risbud, SH Kang, I AF Guha, S Leppert, VJ Risbud, SH Kang, I TI Observation of excitonic states in PbSe nanocrystals SO SOLID STATE COMMUNICATIONS LA English DT Article ID SIZE; EMISSION; GLASSES AB We report the observation of excitonic states in PbSe nanocrystals with a size distribution varying between 2 and 6 nm. Size selective photoluminescence (PL) and PL excitation spectroscopy (PLE) are used to probe the discrete excitonic states associated with PbSe nanocrystals. By using various excitation wavelengths, we observed two broad PL bands between 300 and 900 nm. These PL bands were identified as the first-and second-exciton recombination in PbSe nanocrystals. A reasonable agreement is obtained between the observed strong bands and calculated oscillator strengths for exciton recombination in PbSe nanocrystals with an average particle size of 4 (+/-2) nm. (C) 1998 Elsevier Science Ltd. C1 USN, Res Lab, Div Condensed Matter & Radiat Sci, Washington, DC 20375 USA. Univ Calif Davis, Dept Chem Engn & Mat Sci, Davis, CA 95616 USA. Cornell Univ, Dept Appl Phys, Ithaca, NY 14853 USA. RP Guha, S (reprint author), USN, Res Lab, Div Condensed Matter & Radiat Sci, Washington, DC 20375 USA. NR 17 TC 21 Z9 22 U1 0 U2 0 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 MAR PY 1998 VL 105 IS 11 BP 695 EP 699 DI 10.1016/S0038-1098(97)10217-4 PG 5 WC Physics, Condensed Matter SC Physics GA YZ742 UT WOS:000072287100007 ER PT J AU Yesinowski, JP AF Yesinowski, JP TI Special issue - Unconventional Methods for Detecting Magnetic Resonance - Foreword SO SOLID STATE NUCLEAR MAGNETIC RESONANCE LA English DT Editorial Material C1 USN, Res Lab, Mat Chem Branch, Washington, DC 20375 USA. RP Yesinowski, JP (reprint author), USN, Res Lab, Mat Chem Branch, Washington, DC 20375 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0926-2040 J9 SOLID STATE NUCL MAG JI Solid State Nucl. Magn. Reson. PD MAR PY 1998 VL 11 IS 1-2 SI SI BP VII EP VII DI 10.1016/S0926-2040(97)00091-X PG 1 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical; Physics, Condensed Matter; Spectroscopy SC Chemistry; Physics; Spectroscopy GA ZT411 UT WOS:000074083000001 ER PT J AU Brown, SW Kennedy, TA Gammon, D AF Brown, SW Kennedy, TA Gammon, D TI Optical NMR from single quantum dots SO SOLID STATE NUCLEAR MAGNETIC RESONANCE LA English DT Article DE optical pumping; Overhauser shift; high sensitivity; quantum dot; GaAs ID NUCLEAR-MAGNETIC-RESONANCE; GALLIUM-ARSENIDE; SPECTROSCOPY; EXCITONS; WELLS AB Nuclear magnetic resonance (NMR) from constituent Ga and As nuclei was optically detected on excitonic recombination in single GaAs quantum dots formed by interface fluctuations in GaAs/Al0.3Ga0.7As quantum wells. Orientation of the nuclear spin system by optical pumping causes an Overhauser shift of the excitonic energy levels proportional to the degree of nuclear orientation. NMR was subsequently detected by monitoring changes in the combined Overhauser plus Zeeman splitting of excitons localized in single quantum dots as the RF frequency was swept through a nuclear resonance. The NMR signals originate from similar to 10(5) nuclei in the quantum dot-with dimensions of approximately 4 nm X 10 nm x 100 nm-illustrating the extreme sensitivity and spatial resolution of the technique. NMR from such small structures provides a chemically specific probe of the local environment on the nanometer scale. (C) 1998 Elsevier Science B.V. C1 USN, Res Lab, Washington, DC 20375 USA. RP Brown, SW (reprint author), USN, Res Lab, Washington, DC 20375 USA. RI Schaff, William/B-5839-2009 NR 22 TC 18 Z9 18 U1 1 U2 11 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0926-2040 J9 SOLID STATE NUCL MAG JI Solid State Nucl. Magn. Reson. PD MAR PY 1998 VL 11 IS 1-2 SI SI BP 49 EP 58 DI 10.1016/S0926-2040(97)00095-7 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical; Physics, Condensed Matter; Spectroscopy SC Chemistry; Physics; Spectroscopy GA ZT411 UT WOS:000074083000005 PM 9650789 ER PT J AU Ellis, RJ Cosby, RL Lees, JA AF Ellis, RJ Cosby, RL Lees, JA TI Pulmonary embolus masquerading as pneumonia in a patient with Hodgkin's disease and nephrotic syndrome SO SOUTHERN MEDICAL JOURNAL LA English DT Article ID HYPERCOAGULABILITY AB Fatal pulmonary embolus is an infrequent cause of death in patients with Hodgkin's disease who respond to initial therapy. This patient had associated minimal change disease and nephrotic syndrome that was responding to therapy, but had this complication. The diagnosis was delayed by the presentation that suggested pneumonia. A high index of suspicion for thrombotic complications and an aggressive diagnostic pursuit thereof are merited in these patients. C1 USN, Med Ctr, Dept Clin Invest, San Diego, CA 92134 USA. USN, Med Ctr, Dept Internal Med, Div Gen Internal Med,Nephrol Div, San Diego, CA 92134 USA. RP Lees, JA (reprint author), USN, Med Ctr, Dept Clin Invest, 34800 Bob Wilson Dr, San Diego, CA 92134 USA. NR 11 TC 1 Z9 1 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 MAR PY 1998 VL 91 IS 3 BP 283 EP 286 PG 4 WC Medicine, General & Internal SC General & Internal Medicine GA 170AC UT WOS:000078782100016 PM 9521373 ER PT J AU Brook, I Frazier, EH AF Brook, I Frazier, EH TI Aerobic and anaerobic infection associated with malignancy SO SUPPORTIVE CARE IN CANCER LA English DT Article DE malignancy; infection; anaerobic bacteria; Staphylococcus aureus; Escherichia coli; abscess ID CANCER-PATIENTS; BACTEREMIA; GROWTH AB The goal of this work was to study the microbiology and clinical characteristics of patients with infections associated with malignancy treated over a period of 17 years. A total of 668 specimens were obtained from 605 patients. The malignancies include 224 hematological malignancies and 381 nonhematogenic malignancies. Anaerobic bacteria only were isolated in 201 (30%) specimens, aerobic bacteria in 226 (34%), mixed aerobic-anaerobic bacteria in 231 (35%) and Candida spp. in 10 (1%). A total of 683 anaerobic (1.0 isolates per specimens) and 592 aerobic or facultative (0.9 per specimen) organ isms were recovered. The predominant anaerobic bacteria included Bacteroides fragilis group isolates (181), Peptostreptococcus spp. (166), Prevotella spp. (106), Clostridium spp. (70), and Fusobacterium spp. (43). The predominant aerobic bacteria included Escherichia coli (133), Staphylococcus aureus (100), Klebsiella pneumoniae (48), and Pseudomonas aeroginosa (45). The type of infections included abscesses (221), bacteremia (198), wounds (175), including 61 cellulitis, 24 post surgical wounds and 23 decubitus ulcers), peritonitis (48), empyema (12), cholecystitis (6) and thrombophlebitis (5). S. aureus and Peptostreptococcus spp. were isolated from all sites. However, organisms of the oropharyngeal flora (Prevotella and Fusobacterium spp.) predominated in local infections and bacteremia that originated from this site (head and neck wounds and abscesses and pulmonary infections), and organisms of the gastrointestinal tract flora predominated in infections that originated from this site (peritonitis, abdominal abscesses and decubitus ulcers). This retrospective study demonstrates polymicrobial features of many infections associated with malignancies. C1 USN Hosp, Dept Pediat, Bethesda, MD USA. USN Hosp, Dept Infect Dis, Bethesda, MD USA. RP Brook, I (reprint author), POB 70412, Chevy Chase, MD 20813 USA. NR 31 TC 22 Z9 22 U1 0 U2 1 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0941-4355 J9 SUPPORT CARE CANCER JI Support. Care Cancer PD MAR PY 1998 VL 6 IS 2 BP 125 EP 131 DI 10.1007/s005200050146 PG 7 WC Oncology; Health Care Sciences & Services; Rehabilitation SC Oncology; Health Care Sciences & Services; Rehabilitation GA ZD249 UT WOS:000072666300009 PM 9540171 ER PT J AU Qadri, SB Khan, HR Skelton, EF Lubitz, P AF Qadri, SB Khan, HR Skelton, EF Lubitz, P TI Indium-doped transparent conducting oxides of ZrO2 SO SURFACE & COATINGS TECHNOLOGY LA English DT Article; Proceedings Paper CT Symposium K on Coatings and Surface Modifications for Surface Protection and Tribological Applications, at ICAM 97 CY JUN 16-20, 1997 CL STRASBOURG, FRANCE DE transparent conducting oxides; ceramic films; ceramic structure ID THIN-FILMS AB Thin films made of varying compositions of ZrxIn1-xOy have been prepared by electron beam evaporation. The (Zr, In)O-y in the films is stabilized in its cubic phase by the In2O3. The electrical resistivity and the wavelength dependence of the optical transparency of the films have been measured, The results are encouraging for potential applications of (Zr,In)O-y as a transparent conducting oxide. (C) 1998 Elsevier Science S.A. C1 USN, Res Lab, Washington, DC 20375 USA. FEM, D-73525 Schwabisch Gmund, Germany. RP USN, Res Lab, Washington, DC 20375 USA. NR 13 TC 3 Z9 3 U1 1 U2 4 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 MAR PY 1998 VL 100 IS 1-3 BP 94 EP 97 DI 10.1016/S0257-8972(97)00595-1 PG 4 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA ZN366 UT WOS:000073638700020 ER PT J AU Mercer, TW Pehrsson, PE AF Mercer, TW Pehrsson, PE TI Surface state transitions on the reconstructed diamond C(100) surface SO SURFACE SCIENCE LA English DT Letter DE carbon; electron energy loss spectroscopy; semiconducting surfaces; surface electronic phenomena ID SCANNING-TUNNELING-MICROSCOPY; NEGATIVE ELECTRON-AFFINITY; AB-INITIO CALCULATIONS; TO-METAL TRANSITION; DIMER RECONSTRUCTION; 100 SURFACES; HYDROGEN; PHOTOEMISSION; INTERFACE; SI(001) AB The diamond C(100) surface was investigated with a high-resolution electron energy loss spectrometer (HREELS) in both the electronic excitation and surface vibrational excitation regimes. The 0-15 eV electronic excitation spectra on the bare C(100) surface revealed three dominant loss features at 3.5, 4.7 and 5.9 eV. These peaks have been attributed to two mid-gap surface states. These states were absent on the H-terminated surface, indicating that they were localized at the surface and were due either to pi-bonded dimers or dangling bonds on the surface. The separation between the states, and their possible positions relative to the valence band maximum, were compared to recent surface band structure calculations, and provide evidence for symmetric dimers on the C(100) surface. (C) 1998 Elsevier Science B.V. C1 USN, Res Lab, Gas Surface Dynam Sect, Washington, DC 20375 USA. RP Pehrsson, PE (reprint author), USN, Res Lab, Gas Surface Dynam Sect, Washington, DC 20375 USA. EM mercer@ccf.nrl.navy.mil NR 24 TC 25 Z9 25 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD MAR 1 PY 1998 VL 399 IS 1 BP L327 EP L331 DI 10.1016/S0039-6028(97)00877-7 PG 5 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA ZD644 UT WOS:000072708000001 ER PT J AU Greason, KL Rappold, JF Liberman, MA AF Greason, KL Rappold, JF Liberman, MA TI Incidental laparoscopic appendectomy for acute right lower quadrant abdominal pain - Its time has come SO SURGICAL ENDOSCOPY-ULTRASOUND AND INTERVENTIONAL TECHNIQUES LA English DT Article; Proceedings Paper CT Annual Meeting of the Society-of-American-Gastrointestinal-Endoscopic-Surgeons CY MAR 19-22, 1997 CL SAN DIEGO, CALIFORNIA SP Soc Amer Gastrointestinal Endoscop Surgeons DE appendectomy; laparoscopy; laparoscopic appendectomy ID APPENDIX AB Background: Removing the normal appendix when operating for suspected acute appendicitis is the standard of care. The use of laparoscopy should not alter this practice. Methods: Retrospective review of 72 patients found to have grossly normal appendices while undergoing laparoscopy for suspected appendicitis. Twenty-eight patients underwent diagnostic laparoscopy (DL) alone while 44 patients underwent diagnostic laparoscopy with incidental laparoscopic appendectomy (ILA). Results: There was no difference in length of hospitalization (DL = 44 h, ILA = 43 h, p = 0.49) or morbidity (DL = 11%, ILA = 5%, p = 0.37). One patient required appendectomy 11 days after diagnostic laparoscopy for recurrent acute right lower quadrant abdominal pain. Five percent of resected appendices (2/44) demonstrated acute inflammation upon pathologic review. Conclusions: Laparoscopic removal of the normal appendix produces no added morbidity or increase in length of hospitalization as compared to diagnostic laparoscopy. It demonstrates cost effectiveness by preventing missed and future appendicitis. Incidental laparoscopic appendectomy is the preferred treatment option. C1 USN, Med Ctr, Dept Gen Surg & Clin Invest, San Diego, CA 92134 USA. RP Liberman, MA (reprint author), USN, Med Ctr, Dept Gen Surg & Clin Invest, 34800 Bob Wilson Dr, San Diego, CA 92134 USA. NR 12 TC 24 Z9 25 U1 0 U2 0 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 MAR PY 1998 VL 12 IS 3 BP 223 EP 225 DI 10.1007/s004649900639 PG 3 WC Surgery SC Surgery GA YZ656 UT WOS:000072277200009 PM 9502700 ER PT J AU Fothergill, DM Taylor, WF Hyde, DE AF Fothergill, DM Taylor, WF Hyde, DE TI Physiologic and perceptual responses to hypercarbia during warm- and cold-water immersion SO UNDERSEA & HYPERBARIC MEDICINE LA English DT Article DE carbon dioxide; thermoregulation; breathlessness; diving; hypercapnia symptoms ID CARBON-DIOXIDE; MODERATE COLD; CO2; HYPERCAPNIA; HUMANS; BREATHLESSNESS; PSYCHOMOTOR; PERFORMANCE; INHALATION; NARCOSIS AB Thermoregulatory, respiratory, and perceptual responses to acute CO2 exposure during light exercise (75 W) were assessed in 12 U.S. Navy divers clad only in swim trunks while immersed to the neck in water at 18 degrees and 34 degrees C. The CO2 exposures consisted of a linear 10-min ramp increase in the inspired fraction of CO2 (FICO2) from 0 to 6% followed by 5 min of breathing 6% CO2. The ability to detect and rate the severity of hypercarbia, as well as subjective changes in thermal comfort, were assessed by comparing subjective ratings given during the CO2 exposures with those given during immersion trials where the FICO2 was maintained at 0%. Hypercarbia was recognized earlier and, at a given PETCO2, was perceived to be greater during cold- than during warm-water immersions (P < 0.01). The CO2 exposures did not affect the thermal balance of divers as assessed by changes in heat flux and rectal temperature. However, increased feelings of warmth were reported during both the cold and warm immersions when breathing raised concentrations of CO2 (P < 0.01). During the cold immersions, acute exposure to 6% CO2 significantly decreased forearm blood flow (P < 0.05), but did not affect finger blood flow. It is concluded that PETCO2 levels can reach unacceptably high concentrations (>60 mmHg) before hypercarbia can be reliably detected by working divers. Furthermore, the ability to detect hypercarbia is poorer when immersed in warm water than when in cold water. C1 USN, Med Res Inst, Bethesda, MD 20889 USA. RP Fothergill, DM (reprint author), Naval Submarine Red Res Lab, Naval Submarine Base New London, Groton, CT 06349 USA. NR 44 TC 8 Z9 8 U1 2 U2 5 PU UNDERSEA & HYPERBARIC MEDICAL SOC INC PI KENSINGTON PA 10531 METROPOLITAN AVE, KENSINGTON, MD 20895 USA SN 1066-2936 J9 UNDERSEA HYPERBAR M JI Undersea Hyperb. Med. PD SPR PY 1998 VL 25 IS 1 BP 1 EP 12 PG 12 WC Marine & Freshwater Biology; Medicine, Research & Experimental SC Marine & Freshwater Biology; Research & Experimental Medicine GA ZH023 UT WOS:000073064400001 PM 9566081 ER PT J AU Lillo, RS Parker, EC AF Lillo, RS Parker, EC TI Evaluation of oxygen and pressure in treatment of decompression sickness in guinea pigs SO UNDERSEA & HYPERBARIC MEDICINE LA English DT Article DE oxygen; decompression sickness; recompression; diving; pressure ID PHYSIOLOGICAL-RESPONSES; VENOUS BUBBLES; EMBOLISM; AIR AB These experiments examined whether increasing the partial pressure of oxygen (PO2), hydrostatic pressure, or both were responsible for the improvement in effectiveness of recompression treatment previously observed in guinea pigs with increasing depths of air. Unanesthetized male guinea pigs (600-700 g) were subjected to 8.6 atm abs (871 kPa) air dives for 60 min and then decompressed at 1.82 atm (184 kPa)/min to the surface. Subsequently, animals usually displayed hypotension, cardiac arrhythmia, and tachypnea, indicative of a fatal bout (> 95% death rate) of decompression sickness (DCS). Animals that developed DCS were treated by recompressing to depths ranging from 2.5 to 11.6 atm abs (253-1175 kPa), with 14, 28, 42, or 100% O-2/balance N-2. This design produced PO2's at treatment depth ranging from 0.4 to 3.6 atm abs (41-365 kPa). Upon recompression, recovery of blood pressure, heart rate, and breathing rate generally occurred. The area under the breathing rate vs. time curve was used to examine the effectiveness of treatment over a period of 60 min. A dramatic improvement in recovery over time was observed with increasing recompression depth for all gas mixtures. Analysis indicated that the positive response to depth was related to increasing hydrostatic pressure; increasing PO2 had no statistically significant beneficial effect. C1 USN, Med Res Inst, Bethesda, MD 20889 USA. RP Lillo, RS (reprint author), USN, Med Res Inst, 8901 Wisconsin Ave, Bethesda, MD 20889 USA. NR 22 TC 2 Z9 2 U1 0 U2 0 PU UNDERSEA & HYPERBARIC MEDICAL SOC INC PI KENSINGTON PA 10531 METROPOLITAN AVE, KENSINGTON, MD 20895 USA SN 1066-2936 J9 UNDERSEA HYPERBAR M JI Undersea Hyperb. Med. PD SPR PY 1998 VL 25 IS 1 BP 51 EP 57 PG 7 WC Marine & Freshwater Biology; Medicine, Research & Experimental SC Marine & Freshwater Biology; Research & Experimental Medicine GA ZH023 UT WOS:000073064400007 PM 9566087 ER PT J AU Blain, CA Westerink, JJ Luettich, RA AF Blain, CA Westerink, JJ Luettich, RA TI Grid convergence studies for the prediction of hurricane storm surge SO INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS LA English DT Article DE storm surge; shallow water model; grid convergence; coastal ocean ID NUMERICAL-MODEL; EQUATION; SIMULATION; PROGRESS; FLOWS AB The focus of this paper is a systematic determination of the relationship between grid resolution and errors associated with computations of hurricane storm surge. A grid structure is sought that provides the spatial resolution necessary to capture pertinent storm surge physics and does not overdiscretize. A set of numerical experiments simulating storm surge generation over 14 grid discretizations of idealized domains examines the influence of grid spacing, shoreline detail, coastline resolution and characteristics of the meteorological forcing on storm surge computations. Errors associated with a given grid are estimated using a Richardson-based error estimator. Analysis of the magnitude and location of estimated errors indicates that underresolution on the continental shelf leads to significant overprediction of the primary storm surge. In deeper waters, underresolution causes smearing or damping of the inverted barometer forcing function, which in turn results in underprediction of the surge elevation. In order to maintain a specified error level throughout the duration of the storm, the highest grid resolution is required on the continental shelf and particularly in nearshore areas. The disparity of discretization requirements between deep waters and coastal regions is best met using a graded grid. Application of the graded gridding strategy to the hindcast of Hurricane Camille reinforces the necessity of using a grid that has high levels of resolution in nearshore regions and areas of complex coastal geometry. (C) 1998 John Wiley & Sons, Ltd. C1 USN, Res Lab, Stennis Space Ctr, MS 39529 USA. Univ Notre Dame, Dept Civil Engn & Geol Sci, Notre Dame, IN 46556 USA. Univ N Carolina, Inst Marine Sci, Morehead City, NC 28557 USA. RP Blain, CA (reprint author), USN, Res Lab, Code 7322, Stennis Space Ctr, MS 39529 USA. NR 36 TC 45 Z9 48 U1 3 U2 4 PU JOHN WILEY & SONS LTD PI CHICHESTER PA THE ATRIUM, SOUTHERN GATE, CHICHESTER PO19 8SQ, W SUSSEX, ENGLAND SN 0271-2091 J9 INT J NUMER METH FL JI Int. J. Numer. Methods Fluids PD FEB 28 PY 1998 VL 26 IS 4 BP 369 EP 401 DI 10.1002/(SICI)1097-0363(19980228)26:4<369::AID-FLD624>3.0.CO;2-0 PG 33 WC Computer Science, Interdisciplinary Applications; Mathematics, Interdisciplinary Applications; Mechanics; Physics, Fluids & Plasmas SC Computer Science; Mathematics; Mechanics; Physics GA YY783 UT WOS:000072184700001 ER PT J AU Campbell, PM Snow, ES AF Campbell, PM Snow, ES TI Proximal probe-based fabrication of nanometer-scale devices 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 atomic force microscope; nanofabrication; oxidation; nanometer-scale devices ID SCANNING TUNNELING MICROSCOPE; ATOMIC-FORCE MICROSCOPE; FIELD-EFFECT TRANSISTORS; SILICON; STM; OXIDATION; OPERATION; SURFACES AB We describe a simple and reliable process for the fabrication of nanometer-scale structures by using the local electric field of a conducting tip atomic force microscope to write surface oxide patterns by local anodic oxidation. These oxide patterns can be used as masks for selective etching to transfer the pattern into the substrate. This process has been used to fabricate side-gated Si field effect transistors with critical features as small as 30 nm. Alternately, this process of anodic oxidation can be used to oxidize completely through thin metal films to make nanometer-scale lateral metal-oxide-metal tunnel junctions. (C) 1998 Published by Elsevier Science S.A. All rights reserved. C1 USN, Res Lab, Washington, DC 20375 USA. RP Campbell, PM (reprint author), USN, Res Lab, Code 6863, Washington, DC 20375 USA. EM campbell@bloch.nrl.navy.mil NR 23 TC 8 Z9 10 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 173 EP 177 DI 10.1016/S0921-5107(97)00255-9 PG 5 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA ZD831 UT WOS:000072728800038 ER PT J AU Jishi, RA White, CT Mintmire, JW AF Jishi, RA White, CT Mintmire, JW TI First-principles simulations of endohedral bromine in BC3 nanotubes SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID BORON-NITRIDE NANOTUBES; CARBON NANOTUBES; ELECTRONIC-STRUCTURE; GROWTH; PHASE; POLYACETYLENE; CAPILLARITY; NITROGEN; TUBULES AB Using first-principles calculations, we investigate the stability of composite systems consisting of BC3 nanotubes with a linear chain of bromine atoms inside. For the BC3 (n,n) nanotubes considered here (n = 2, 3, 4), we find that the binding energy per bromine atom exceeds its corresponding value in solid, liquid-phase, or gas-phase bromine. Charge transfer from the BC3 nanotube to the bromine chain results in hole pockets in the valence sigma bands of the BC3 wall. C1 USN, Div Chem, Res Lab, Washington, DC 20375 USA. Calif State Univ Los Angeles, Dept Phys & Astron, Los Angeles, CA 90032 USA. RP Mintmire, JW (reprint author), USN, Div Chem, Res Lab, Washington, DC 20375 USA. OI Mintmire, John/0000-0002-6551-0349 NR 36 TC 14 Z9 14 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD FEB 26 PY 1998 VL 102 IS 9 BP 1568 EP 1570 DI 10.1021/jp9730407 PG 3 WC Chemistry, Physical SC Chemistry GA YZ899 UT WOS:000072305600012 ER PT J AU Riley, T AF Riley, T TI Epilepsy - Video atlas of epileptic seizures: Classical examples SO JAMA-JOURNAL OF THE AMERICAN MEDICAL ASSOCIATION LA English DT Software Review C1 USN, Pensacola, FL 32508 USA. RP Riley, T (reprint author), USN, Pensacola, FL 32508 USA. NR 0 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 25 PY 1998 VL 279 IS 8 BP 633 EP 633 DI 10.1001/jama.279.8.633 PG 1 WC Medicine, General & Internal SC General & Internal Medicine GA YX457 UT WOS:000072041900044 ER PT J AU Collins, GE Choi, LS Callahan, JH AF Collins, GE Choi, LS Callahan, JH TI Effect of solvent polarity, pH, and metal complexation on the triple fluorescence of 4-(N-1,4,8,11-tetraazacyclotetradecyl)benzonitrile SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID INTRAMOLECULAR CHARGE-TRANSFER; ANOMALOUS FLUORESCENCE; MOLECULAR-STRUCTURE; EXCIPLEX SYSTEMS; AQUEOUS-SOLUTION; EXCITED-STATES; IONS; DONOR AB Triple fluorescence is observed for 3-(N-1,4,8,11-tetraazacyclotetradecyl)benzonitrile (DMABN-Cyclam) in ethanol, corresponding to a locally excited (LE) singlet state, a twisted intramolecular charge-transfer (TICT) state. and an intramolecular exciplex (E). The LE state emission dominates the spectrum in nonpolar solvents such as n-hexane, while polar solvents stabilize the charge-transfer states, TICT and E. Optimal intramolecular exciplex emission, however, was observed in toluene, while the TICT band was maximal in water. The influence of pH on the fluorescent properties of DMABN-Cyclam were studied, indicating that protonation of cyclam strongly influences the equilibria existing between the three excited-state species, as well as the extent of quenching apparent for each excited-state band. DMABN-Cyclam uniquely responded to the addition of micromolar quantities of transition metal cations with varying changes in the triple fluorescence emission. C1 USN, Res Lab, Div Chem, Washington, DC 20375 USA. RP Collins, GE (reprint author), USN, Res Lab, Div Chem, Code 6116, Washington, DC 20375 USA. NR 26 TC 47 Z9 49 U1 0 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD FEB 25 PY 1998 VL 120 IS 7 BP 1474 EP 1478 DI 10.1021/ja972169r PG 5 WC Chemistry, Multidisciplinary SC Chemistry GA YZ359 UT WOS:000072246500019 ER PT J AU Pinto, JF Esterowitz, L Carrig, TJ AF Pinto, JF Esterowitz, L Carrig, TJ TI Extended wavelength coverage of a Ce3+: LiCAF laser between 223 and 243 nm by sum frequency mixing in beta-barium borate SO APPLIED OPTICS LA English DT Article ID ULTRAVIOLET-LASER AB We obtained coherent radiation in the spectral region between 223 and 243 nm by frequency mixing the tunable output of a solid-state Ce3+:LiCAF laser with 1.064-mu m radiation from a Nd3+:YAG pump laser in a beta-barium borate nonlinear crystal. (C) 1998 Optical Society of America. C1 USN, Res Lab, Washington, DC 20375 USA. RP Pinto, JF (reprint author), USN, Res Lab, Code 5641, Washington, DC 20375 USA. NR 6 TC 7 Z9 7 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 FEB 20 PY 1998 VL 37 IS 6 BP 1060 EP 1061 DI 10.1364/AO.37.001060 PG 2 WC Optics SC Optics GA YW353 UT WOS:000071926500015 PM 18268686 ER PT J AU Harris, MJ Share, GH AF Harris, MJ Share, GH TI A search for hard-spectrum gamma-ray bursts using SMM SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays, bursts; surveys ID HIGH-ENERGY EMISSION; EVENTS; BATSE; LONG AB We have searched over 9 yr of data from the Solar Maximum Mission (SMM) Gamma Ray Spectrometer for gamma-ray bursts (GRBs) with abnormally hard spectra that may have been missed in previous searches in the 0.35-0.8 MeV energy band. For this purpose, we searched the higher 0.8-10 MeV band. We have found only two new GRBs in this search, compared to 177 GRBs found in the 0.35-0.8 MeV band. We have made a careful examination of the threshold conditions for identifying the 0.8-10 MeV events. which confirms that there is no undiscovered population of hard-spectrum GRBs that have escaped detection by SMM, BATSE, and other instruments triggered by low-energy gamma-ray emission. This conclusion does not apply to GRBs with duration less than 2 s, nor to those that are much fainter than the general population. Our results constrain models of GRBs that require or allow the peak in energy emission to be above 1 MeV. C1 Univ Space Res Assoc, Washington, DC 20024 USA. USN, Res Lab, Washington, DC 20375 USA. RP Harris, MJ (reprint author), Univ Space Res Assoc, 300 D St SW,Suite 801, Washington, DC 20024 USA. NR 27 TC 30 Z9 30 U1 0 U2 0 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 724 EP 733 DI 10.1086/305227 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA YZ796 UT WOS:000072292500020 ER PT J AU Combi, MR Brown, ME Feldman, PD Keller, HU Meier, RR Smyth, WH AF Combi, MR Brown, ME Feldman, PD Keller, HU Meier, RR Smyth, WH TI Hubble Space Telescope ultraviolet imaging and high-resolution spectroscopy of water photodissociation products in comet Hyakutake (C/1996 B2) SO ASTROPHYSICAL JOURNAL LA English DT Article DE comets, individual (Hyakutake); molecular processes; ultraviolet, solar system ID LYMAN-ALPHA; IUE OBSERVATIONS; PRODUCTION-RATES; HYDROGEN; OH; ATMOSPHERES; P/HALLEY; FLUORESCENCE; H2O AB Comet Hyakutake (C/1996 B2) provided a target of opportunity for performing a systematic study of water photodissociation products in which we obtained data from three instruments on the Hubble Space Telescope (HST). The HST Goddard High Resolution Spectrograph (GHRS) was used to measure the line profile of hydrogen Ly alpha (H Ly alpha) at six locations around the coma of the comet, ranging from the nucleus to a displacement of 100,000 km, and covering different directions compared with the comet-sun line. GHRS yielded line profiles with a spectral resolution (FWHM similar to 4 km s(-1)) that was a factor of 2-3 better than any previous H Ly alpha or H alpha ground-based measurements. The Wide Field Planetary Camera 2 (WFPC2) and the Woods filter were used to obtain H Ly alpha images of the inner coma. Th faint object spectrograph (FOS) was used to determine the OH production rate and monitor its variation throughout the HST observing sequence. The GHRS H Ly alpha line profiles show the behavior of a line profile that is optically thick in the core for positions near the nucleus (<5000 km) and gradually becoming more optically thin at larger displacements and lower column abundances. A composite H Ly alpha image constructed from four separate WFPC3 exposures is consistent with the relative fluxes seen in GHRS observations and clearly shows the dayside enhancement of a solar illuminated optically thick coma. These data were analyzed self-consistently to test our understanding of the detailed physics and chemistry of the expanding coma and our ability to obtain accurate water production rates from remote observations of gaseous hydrogen (H) and hydroxyl (OH), the major water dissociation products. Our hybrid kinetic/hydrodynamic model of the coma combined with a spherical radiative transfer calculation is able to account for (1) the velocity distribution of H atoms, (2) the spatial distribution of the H Ly alpha emission in the inner coma, and (3) the absolute intensities of H and OH emissions, giving a water production rate of (2.6 +/- 0.4) x 10(29) s(-1) on 1996 April 4. C1 Univ Michigan, Space Phys Res Lab, Ann Arbor, MI 48109 USA. CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Max Planck Inst Aeron, D-37191 Katlenburg Lindau, Germany. USN, Res Lab, EO Hulburt Ctr Space Res, Washington, DC 20375 USA. Atmospher & Environm Res Inc, Cambridge, MA 02139 USA. RP Combi, MR (reprint author), Univ Michigan, Space Phys Res Lab, 2455 Hayward St, Ann Arbor, MI 48109 USA. EM mcombi@umich.edu RI Combi, Michael/J-1697-2012; Meier, Robert/G-4749-2014 OI Combi, Michael/0000-0002-9805-0078; Meier, Robert/0000-0001-8497-7115 NR 40 TC 24 Z9 24 U1 0 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 816 EP + DI 10.1086/305228 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA YZ796 UT WOS:000072292500032 ER PT J AU Titi, RJ AF Titi, RJ TI On the defense SO HOSPITALS & HEALTH NETWORKS LA English DT Letter C1 USN, Med Serv Corps, Quantico, VA 22134 USA. RP Titi, RJ (reprint author), USN, Med Serv Corps, Quantico, VA 22134 USA. NR 0 TC 0 Z9 0 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 FEB 20 PY 1998 VL 72 IS 4 BP 10 EP 10 PG 1 WC Health Policy & Services SC Health Care Sciences & Services GA YX765 UT WOS:000072075000002 ER PT J AU Nedoluha, GE Bevilacqua, RM Gomez, RM Siskind, DE Hicks, BC Russell, JM Connor, BJ AF Nedoluha, GE Bevilacqua, RM Gomez, RM Siskind, DE Hicks, BC Russell, JM Connor, BJ TI Increases in middle atmospheric water vapor as observed by the Halogen Occultation Experiment and the ground-based Water Vapor Millimeter-wave Spectrometer from 1991 to 1997 SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID UPPER MESOSPHERE; GRAVITY-WAVES; STRATOSPHERE; OZONE; TRANSPORT; H2O; CH4 AB Water vapor measurements made by the Halogen Occultation Experiment (HALOE) from 1991 to 1997 are compared with ground-based observations by the Water Vapor Millimeter-wave Spectrometers (WVMS) taken from 1992 to 1997 at Table Mountain, California (34.4 degrees N, 242.3 degrees E), and at Lauder, New Zealand (45.0 degrees S, 169.7 degrees E). The HALOE measurements show that an upward trend in middle atmospheric water vapor is present at all latitudes. The average trend in the HALOE water vapor retrievals at all latitudes in the 40-60 km range is 0.129 ppmv/yr, while the average trend observed by the WVMS instruments in this altitude range is 0.148 ppmv/yr. This trend is occurring below the altitude where changes in Lyman a associated with solar cycle variations should produce a significant increase in water vapor during this period, and is much larger than the similar to 0.02 ppmv/yr trend in water vapor associated with increases in methane entering the stratosphere. In addition to the water vapor increase, HALOE measurements show that there is a temporal decrease in methane at altitudes between 40 and 70 km. This indicates an increase in the conversion of the available methane to water vapor, thus contributing to the observed increase in water vapor. The increase in water vapor observed by both instruments is larger than that which would be expected from the sum of all of the above effects. We therefore conclude that there has been a significant increase in the amount of water vapor entering the middle atmosphere. A temperature increase of similar to 0.1K/yr in regions of stratosphere-troposphere exchange could increase the saturation mixing ratio of water vapor by an amount consistent with the observed increase. C1 USN, Res Lab, Washington, DC 20375 USA. Hampton Univ, Dept Phys, Hampton, VA 23668 USA. Natl Inst Water & Atmospher Res, Lauder, New Zealand. RP Nedoluha, GE (reprint author), USN, Res Lab, 4555 Overlook Ave SW, Washington, DC 20375 USA. EM nedoluha@wvms.nrl.navy.mil NR 19 TC 84 Z9 85 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 FEB 20 PY 1998 VL 103 IS D3 BP 3531 EP 3543 DI 10.1029/97JD03282 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA YY455 UT WOS:000072148300015 ER PT J AU Krowne, CM AF Krowne, CM TI Nonlinear electromagnetic wave propagation in ferroelectric integrated structures SO MICROWAVE AND OPTICAL TECHNOLOGY LETTERS LA English DT Article DE nonlinear films; ferroelectric materials; TE modes; coplanar guide; electromagnetic fields ID THIN-FILMS AB The complete theory for the electromagnetic solution of the canonical representation of a coplanar integrated circuit structure is provided in the regime of moderate nonlinearity of a ferroelectic film sandwiched between a superstrate and a substrate. The solution is valid for both second-and third-order polarization effects turned on. The relationship to earlier work with only third-order polarization present is given. (C) 1998 John Wiley & Sons, Inc. C1 USN, Res Lab, Div Elect Sci & Technol, Microwave Technol Branch, Washington, DC 20375 USA. RP USN, Res Lab, Div Elect Sci & Technol, Microwave Technol Branch, Washington, DC 20375 USA. NR 26 TC 8 Z9 8 U1 0 U2 0 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0895-2477 EI 1098-2760 J9 MICROW OPT TECHN LET JI Microw. Opt. Technol. Lett. PD FEB 20 PY 1998 VL 17 IS 3 BP 213 EP 225 DI 10.1002/(SICI)1098-2760(19980220)17:3<213::AID-MOP18>3.0.CO;2-5 PG 13 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA YT029 UT WOS:000071556900018 ER PT J AU Boos, JB Bennett, BR Kruppa, W Park, D Yang, MJ Shanabrook, BV AF Boos, JB Bennett, BR Kruppa, W Park, D Yang, MJ Shanabrook, BV TI AlSb/InAs HEMTs using modulation InAs(Si)-doping SO ELECTRONICS LETTERS LA English DT Article AB AlSb/InAs HEMTs have been fabricated using Si-coping in a very thin (9 Angstrom) InAs layer located in the upper AlSb barrier. Quantum Hall measurements show that there is no parallel channel. Devices with a 0.5 mu m gate length exhibit a drain current density of > 1A/mm and an f(T)L(g) product of 30 GHz mu m at V-DS = 0.4 V after correction for the gate bonding pad capacitance. C1 USN, Res Lab, Washington, DC 20375 USA. RP Boos, JB (reprint author), USN, Res Lab, Washington, DC 20375 USA. RI Bennett, Brian/A-8850-2008 OI Bennett, Brian/0000-0002-2437-4213 NR 7 TC 8 Z9 8 U1 0 U2 0 PU IEE-INST ELEC ENG PI HERTFORD PA MICHAEL FARADAY HOUSE SIX HILLS WAY STEVENAGE, HERTFORD SG1 2AY, ENGLAND SN 0013-5194 J9 ELECTRON LETT JI Electron. Lett. PD FEB 19 PY 1998 VL 34 IS 4 BP 403 EP 404 DI 10.1049/el:19980219 PG 2 WC Engineering, Electrical & Electronic SC Engineering GA YZ226 UT WOS:000072232900061 ER PT J AU Dermer, CD Chiang, J AF Dermer, CD Chiang, J TI Electron acceleration and synchrotron radiation in decelerating plasmoids SO NEW ASTRONOMY LA English DT Article DE galaxies : active; galaxies : jets; gamma rays : bursts; gamma rays : theory; radiation mechanisms : non-thermal ID GAMMA-RAY BURSTS; RELATIVISTIC FIREBALLS; PARTICLE-ACCELERATION; EMISSION; MODELS; BATSE; WAVES AB An equation is derived to calculate the dynamics of relativistic magnetized plasma which decelerates by sweeping up matter from the ISM. Reduction to the non-radiative and radiative regimes is demonstrated for the general case of a collimated plasmoid whose area increases as a power of distance x from the explosion, and in the specific case of a blast-wave geometry where the area increases quadratically with x. An equation for the evolution of the electron momentum distribution function in the comoving fluid frame is used to calculate the observed synchrotron radiation spectrum. The central uncertainty involves the mechanism for transfering energy from the non-thermal protons to the electrons. The simplest prescription is to assume that a fixed fraction of the comoving proton power is instantaneously transformed into a power-law, "shock"-like electron distribution function. This permits an analytic solution for the case of a relativistic plasmoid with a constant internal magnetic field. Effects of parameter changes are presented. Breaks in the temporal behavior of the primary burst emission and long wavelength afterglows occur on two time scales for external ISM density distributions n(ext) proportional to x(-eta). The first, as emphasized by Meszaros & Rees, represents the time when the outflow sweeps up approximate to M(th)/Gamma(0) of material from the ISM, where M(th) is the mass in the outflow ejecta and Gamma(0) is the initial Lorentz factor of the plasmoid. The second represents the time when synchrotron cooling begins strongly to regulate the number of nonthermal electrons that are producing radiation which is observed at a given energy. Results are applied to GRB and blazar variability. The slopes of the time profiles of the X-ray and optical light curves of the afterglows of GRB 970228 and GRB 970508 are explained by injection of hard electron spectra with indices s<2 in a deceleration regime near the radiative limit. We also propose that blazar flares are due to the transformation of the directed kinetic energy of the plasmoid when interacting with the external medium, as would occur if relativistic outflows pass through clouds orbiting the central supermassive black hole. Published by Elsevier Science B.V. C1 USN, Res Lab, EO Hulburt Ctr Space Res, Washington, DC 20375 USA. RP Dermer, CD (reprint author), USN, Res Lab, EO Hulburt Ctr Space Res, Code 7653, Washington, DC 20375 USA. EM dermer@osse.nrl.navy.mil; chiang@osse.nrl.navy.mil NR 48 TC 34 Z9 34 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1384-1076 J9 NEW ASTRON JI New Astron. PD FEB 18 PY 1998 VL 3 IS 3 BP 157 EP 173 DI 10.1016/S1384-1076(98)00004-9 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA YY992 UT WOS:000072209100002 ER PT J AU Meyer, JR AF Meyer, JR TI Quantum well laser design - Introduction SO OPTICS EXPRESS LA English DT Editorial Material C1 USN, Res Lab, Washington, DC 20375 USA. RP Meyer, JR (reprint author), USN, Res Lab, Washington, DC 20375 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1094-4087 J9 OPT EXPRESS JI Opt. Express PD FEB 16 PY 1998 VL 2 IS 4 BP 118 EP 118 PG 1 WC Optics SC Optics GA 122CG UT WOS:000076052600001 ER PT J AU Vurgaftman, I Meyer, JR AF Vurgaftman, I Meyer, JR TI High-temperature HgTe/CdTe multiple-quantum-well lasers SO OPTICS EXPRESS LA English DT Article ID CHEMICAL-VAPOR-DEPOSITION; THEORETICAL PERFORMANCE; HETEROSTRUCTURE LASERS; OPTICAL-PROPERTIES; HGCDTE; SUPERLATTICES; LAYER; CDTE AB While most previous studies of Hg-based mid-IR lasers have focused on either bulk Hg1-xCdxTe alloys or thick (> 100 Angstrom) Hg1-xCdxTe quantum wells with relatively large x, we show that much thinner (20-30 Angstrom) HgTe binary wells may be engineered to suppress both Auger recombination and intervalence free carrier absorption. On the basis of detailed numerical simulations, we predict 4.3 mu m cw emission at temperatures up to 220 K for optical pumping and 105 K for diode operation. In pulsed mode, we expect maximum lasing temperatures more than 100 K higher than any prior Hg-based mid-IR result. (C) 1998 Optical Society of America. C1 USN, Res Lab, Washington, DC 20375 USA. RP Vurgaftman, I (reprint author), USN, Res Lab, Code 5613, Washington, DC 20375 USA. NR 23 TC 5 Z9 5 U1 0 U2 1 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1094-4087 J9 OPT EXPRESS JI Opt. Express PD FEB 16 PY 1998 VL 2 IS 4 BP 137 EP 142 PG 6 WC Optics SC Optics GA 122CG UT WOS:000076052600005 PM 19377592 ER PT J AU Carroll, TL AF Carroll, TL TI Multiple attractors and periodic transients in synchronized nonlinear circuits SO PHYSICS LETTERS A LA English DT Article ID CHAOTIC SYSTEMS AB I study a pair of synchronized nonlinear circuits which may be periodic or chaotic. The circuits are synchronized by a one-way driving signal from the drive circuit to the response circuit. Because the nonlinearities are symmetric about zero, the drive circuit has two periodic attractors. When the value of a bifurcation parameter is above a certain threshold, the response circuit also has two periodic attractors, one in-sync with the drive and one out-of-sync. Below the threshold, the drive circuit still has two attractors but the response circuit has only one attractor, the in-sync attractor. If the response circuit is started in the basin of attraction of the former out-of-sync attractor, a long periodic transient (many cycles long) is seen. (C) 1998 Published by Elsevier Science B.V. C1 USN, Res Lab, Washington, DC 20375 USA. RP USN, Res Lab, Code 6343, Washington, DC 20375 USA. OI Carroll, Thomas/0000-0002-2371-2049 NR 14 TC 3 Z9 4 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9601 EI 1873-2429 J9 PHYS LETT A JI Phys. Lett. A PD FEB 16 PY 1998 VL 238 IS 6 BP 365 EP 368 DI 10.1016/S0375-9601(97)00755-X PG 4 WC Physics, Multidisciplinary SC Physics GA ZC841 UT WOS:000072623600008 ER PT J AU Sheldon, IV Taylor, H AF Sheldon, IV Taylor, H TI Intrathecal narcotics for labor analgesia SO AMERICAN FAMILY PHYSICIAN LA English DT Letter ID EPIDURAL ANALGESIA C1 USN Hosp, Jacksonville, FL 32214 USA. RP Sheldon, IV (reprint author), USN Hosp, 2080 Child St, Jacksonville, FL 32214 USA. NR 3 TC 0 Z9 0 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 FEB 15 PY 1998 VL 57 IS 4 BP 640 EP 641 PG 2 WC Primary Health Care; Medicine, General & Internal SC General & Internal Medicine GA YX911 UT WOS:000072093100009 PM 9490988 ER PT J AU Stephens, MB AF Stephens, MB TI Intrathecal narcotics for labor analgesia - In reply SO AMERICAN FAMILY PHYSICIAN LA English DT Letter ID EPIDURAL ANALGESIA; SUFENTANIL; DELIVERY C1 USN, Med Ctr, San Diego Primary Care Grp, San Diego, CA 92106 USA. RP Stephens, MB (reprint author), USN, Med Ctr, San Diego Primary Care Grp, 2650 Stockton Rd,Bldg 624, San Diego, CA 92106 USA. RI Stephens, Mark/A-2679-2015 NR 10 TC 0 Z9 0 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 FEB 15 PY 1998 VL 57 IS 4 BP 642 EP + PG 3 WC Primary Health Care; Medicine, General & Internal SC General & Internal Medicine GA YX911 UT WOS:000072093100011 ER PT J AU Schafer, DR Thompson, LDR Smith, BC Wenig, BM AF Schafer, DR Thompson, LDR Smith, BC Wenig, BM TI Primary ameloblastoma of the sinonasal tract - A clinicopathologic study of 24 cases SO CANCER LA English DT Article; Proceedings Paper CT Annual Meeting of the American-Academy-of-Oral-and-Maxillofacial-Pathology CY MAY 03-07, 1997 CL VANCOUVER, CANADA SP Amer Acad Oral & Maxillofacial Pathol DE ameloblastoma; nasal cavity; paranasal sinuses; treatment; prognosis ID MAXILLARY AMELOBLASTOMA; PERIPHERAL AMELOBLASTOMA AB BACKGROUND. Ameloblastomas are locally aggressive jaw tumors with a high propensity for recurrence and are believed to arise from the remnants of odontogenic epithelium. Extragnathic ameloblastomas are unusual and primary sinonasal tract origin is extraordinarily uncommon. METHODS. Twenty-four cases of ameloblastoma confined to the sinonasal tract were retrieved from the Otorhinolaryngic-Head & Neck Pathology and Oral-Maxillofacial Pathology Tumor Registries of the Armed Forces Institute of Pathology between 1956 and 1996. RESULTS. The patients included 5 females and 19 males with an age range of 43-81 years, with a mean age at presentation of 59.7 years. The patients presented with an enlarging mass in the maxillary sinus or nasal cavity (n = 24), sinusitis (n = 9), or epistaxis (n = 8). Unilateral opacification of the maxillary sinus (n = 12) was the most common radiographic finding. Histologically, the tumors exhibited the characteristic features of ameloblastoma, including peripherally palisaded columnar cells with reverse polarity, The majority of the tumors showed a plexiform growth pattern. Fifteen tumors demonstrated surface epithelial derivation. Surgical excision is the treatment of choice, ranging from conservative surgery (polypectomy) to more aggressive surgery (radical maxillectomy). Five patients experienced at least 1 recurrence, usually within 1 year of initial surgery. With follow-up intervals of up to 44 years (mean, 9.5 years), all 24 patients were alive without evidence of disease or had died of unrelated causes, without evidence of disease. CONCLUSIONS. Primary ameloblastoma of the sinonasal tract is rare. In contrast to their gnathic counterparts, sinonasal tract tumors have a predilection for older age men. Therapy should be directed toward complete surgical resection to prevent local tumor recurrence. (C) 1998 American Cancer Society. C1 Armed Forces Inst Pathol, Dept Oral Maxillofacial Pathol, Washington, DC 20306 USA. Armed Forces Inst Pathol, Dept Endocrine & Otorhinolaryng Head & Neck Patho, Washington, DC 20306 USA. RP Schafer, DR (reprint author), USN, Natl Naval Dent Ctr, Dept Oral & Maxillofacial Pathol, 8901 Wisconsin Ave, Bethesda, MD 20889 USA. RI Thompson, Lester/J-8404-2016 OI Thompson, Lester/0000-0003-3714-1432 NR 35 TC 22 Z9 22 U1 0 U2 3 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 FEB 15 PY 1998 VL 82 IS 4 BP 667 EP 674 DI 10.1002/(SICI)1097-0142(19980215)82:4<667::AID-CNCR8>3.0.CO;2-I PG 8 WC Oncology SC Oncology GA YW148 UT WOS:000071903300008 PM 9477098 ER PT J AU Hintsa, EJ Newman, PA Jonsson, HH Webster, CR May, RD Herman, RL Lait, LR Schoeberl, MR Elkins, JW Wamsley, PR Dutton, GS Bui, TP Kohn, DW Anderson, JG AF Hintsa, EJ Newman, PA Jonsson, HH Webster, CR May, RD Herman, RL Lait, LR Schoeberl, MR Elkins, JW Wamsley, PR Dutton, GS Bui, TP Kohn, DW Anderson, JG TI Dehydration and denitrification in the Arctic polar vortex during the 1995-1996 winter SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID LOWER STRATOSPHERE; CONDENSATION NUCLEI; HYDROGEN BUDGET; NASA ER-2; AIRCRAFT; CLOUD; PARTICLES; NITROGEN; AEROSOL; HNO3 AB Dehydration of more than 0.5 ppmv water was observed between 18 and 19 km (theta similar to 450-465 K) at the edge of the Arctic polar vortex on February 1, 1996. More than half the reactive nitrogen (NO,) had also been removed, with layers of enhanced NO, at lower altitudes. Back trajectory calculations show that air parcels sampled inside the vortex had experienced temperatures as low as 188 K within the previous 12 days, consistent with a small amount of dehydration. The depth of the dehydrated layer (similar to 1 km) and the fact that trajectories passed through the region of ice saturation in one day imply selective growth of a small fraction of particles to sizes large enough (>10 mu m) to be irreversibly removed on this timescale. Over 25% of the Arctic vortex in a 20-30 K range of theta is estimated to have been dehydrated in this event. C1 Harvard Univ, Dept Chem & Biol Chem, Cambridge, MA 02138 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. USN, Postgrad Sch, Dept Meteorol, Monterey, CA 94943 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80307 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Hintsa, EJ (reprint author), Harvard Univ, Dept Chem & Biol Chem, Cambridge, MA 02138 USA. RI Newman, Paul/D-6208-2012; Herman, Robert/H-9389-2012 OI Newman, Paul/0000-0003-1139-2508; Herman, Robert/0000-0001-7063-6424 NR 19 TC 31 Z9 31 U1 0 U2 3 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 15 PY 1998 VL 25 IS 4 BP 501 EP 504 DI 10.1029/98GL00115 PG 4 WC Geosciences, Multidisciplinary SC Geology GA YY192 UT WOS:000072122500024 ER PT J AU Fine, B Gaglione, AM Myasnikov, A Rosenberger, G Spellman, D AF Fine, B Gaglione, AM Myasnikov, A Rosenberger, G Spellman, D TI A classification of fully residually free groups of rank three or less SO JOURNAL OF ALGEBRA LA English DT Article ID MODEL-THEORY AB A group G is fully residually free provided to every finite set S subset of G \ {1} of non-trivial elements of G there is a free group F-S and an epimorphism h(S): G --> F-S such that h(S)(g) not equal 1 for all g is an element of S. If n is a positive integer, then a group G is n-free provided every subgroup of G generated by n or fewer distinct elements is free. Our main result shows that a fully residually free group of rank at most 3 is either abelian, free, or a free rank one extension of centralizers of a rank two free group. To prove this we prove that every 2-free, fully residually free group is actually 3-free. There are fully residually free groups which are not 2-free and there are 3-free, fully residually free groups which are not 4-free. (C) 1998 Academic Press. C1 Fairfield Univ, Dept Math, Fairfield, CT 06430 USA. USN Acad, Dept Math, Annapolis, MD 21402 USA. CUNY City Coll, Dept Math, New York, NY 10031 USA. Univ Dortmund, Fachbereich Math, D-44227 Dortmund, Germany. St Joseph Univ, Dept Math, Philadelphia, PA 19131 USA. RP Fine, B (reprint author), Fairfield Univ, Dept Math, Fairfield, CT 06430 USA. NR 30 TC 16 Z9 16 U1 0 U2 0 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-8693 J9 J ALGEBRA JI J. Algebra PD FEB 15 PY 1998 VL 200 IS 2 BP 571 EP 605 DI 10.1006/jabr.1997.7205 PG 35 WC Mathematics SC Mathematics GA ZB959 UT WOS:000072525500008 ER PT J AU Lovett-Racke, AE Trotter, JL Lauber, J Perrin, PJ June, CH Racke, MK AF Lovett-Racke, AE Trotter, JL Lauber, J Perrin, PJ June, CH Racke, MK TI Decreased dependence of myelin basic protein-reactive T cells on CD28-mediated costimulation in multiple sclerosis patients - A marker of activated/memory T cells SO JOURNAL OF CLINICAL INVESTIGATION LA English DT Article DE costimulation; immunological memory; multiple sclerosis; myelin basic protein; T cells ID EXPERIMENTAL ALLERGIC ENCEPHALOMYELITIS; FINE SPECIFICITY; LYMPHOCYTE-T; NEGATIVE REGULATOR; CLONAL ANERGY; CTLA-4; ACTIVATION; ANTIGEN; FREQUENCY; BLOCKADE AB Although multiple sclerosis (MS) patients and healthy individuals have similar frequencies of myelin basic protein (MBP)-specific T cells, the activation state of these cells has not been well characterized, Therefore, we investigated the dependence of MBP-reactive T cells on CD28-mediated costimulation in MS patients, healthy controls, and stroke patients, MBP-reactive T cells from healthy controls and stroke patients failed to proliferate efficiently when costimulation was blocked using anti-CD28, consistent with a naive T cell response. In contrast, MBP-specific T cell proliferation was not inhibited, or was only partially inhibited when CD28-mediated costimulation was blocked in MS patients. Blockade of CD28 failed to inhibit tetanus toxoid-specific T cell proliferation in both the controls and MS patients, demonstrating that memory cells are not dependent on CD28-mediated costimulation, Limiting dilution analysis indicated that the frequency of MBP-reactive T cells was significantly decreased in healthy controls compared with MS patients when CD28-mediated costimulation was blocked, These data suggest that MBP-reactive T cells are more likely to have been activated in vivo and/or differentiated into memory T cells in MS patients compared with controls, indicating that these cells may be participating in the pathogenesis of MS. C1 Washington Univ, Sch Med, Dept Neurol, St Louis, MO 63110 USA. Univ Penn, Sch Med, Dept Med, Philadelphia, PA 19104 USA. USN, Med Res Inst, Immune Cell Biol Program, Bethesda, MD 20889 USA. RP Lovett-Racke, AE (reprint author), Washington Univ, Sch Med, Dept Neurol, 660 S Euclid Ave, St Louis, MO 63110 USA. RI Lovett-Racke, Amy/E-3545-2011 FU NINDS NIH HHS [R01 NS29851] NR 32 TC 185 Z9 186 U1 0 U2 1 PU ROCKEFELLER UNIV PRESS PI NEW YORK PA 1114 FIRST AVE, 4TH FL, NEW YORK, NY 10021 USA SN 0021-9738 J9 J CLIN INVEST JI J. Clin. Invest. PD FEB 15 PY 1998 VL 101 IS 4 BP 725 EP 730 DI 10.1172/JCI1528 PG 6 WC Medicine, Research & Experimental SC Research & Experimental Medicine GA YY869 UT WOS:000072195300001 PM 9466965 ER PT J AU Gallagher, EL Elgar, S Guza, RT AF Gallagher, EL Elgar, S Guza, RT TI Observations of sand bar evolution on a natural beach SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID CROSS-SHORE CURRENTS; PLANE SLOPING BEACH; SEDIMENT TRANSPORT; SURF-ZONE; NEARSHORE; MODEL; ENVIRONMENT; GENERATION AB Waves, currents, and the location of the seafloor were measured on a barred beach for about 2 months at nine locations along a cross-shore transect extending 255 m from 1 to 4 m water depth. The seafloor location was measured nearly continuously, even in the surf zone during storms, with sonar altimeters mounted on fixed frames. The crest of a sand bar initially located about 60 m from the shoreline moved 130 m offshore (primarily when the offshore significant wave height exceeded about 2 m), with 1.5 m of erosion near the initial location and I m of accretion at the final location. An energetics-type sediment transport model driven by locally measured near-bottom currents predicts the observed offshore bar migration, but not the slow onshore migration observed during low-energy wave conditions. The predicted offshore bar migration is driven primarily by cross-shore gradients in predicted suspended sediment transport associated with quasi-steady, near-bottom, offshore flows. These strong (> 50 cm/s) currents, intensified near the bar crest by wave breaking, are predicted to cause erosion on the shoreward slope of the bar and deposition on the seaward side. The feedback amoung morphology, waves, circulation, and sediment transport thus forces offshore bar migration during storms. C1 USN, Postgrad Sch, Dept Oceanog, Monterey, CA 93943 USA. Washington State Univ, Sch Elect Engn & Comp Sci, Pullman, WA 99164 USA. Univ Calif San Diego, Scripps Inst Oceanog, Ctr Coastal Studies, La Jolla, CA 92093 USA. RP USN, Postgrad Sch, Dept Oceanog, 833 Dyer Rd,Rm 328, Monterey, CA 93943 USA. EM egallagh@oc.nps.navy.mil; elgar@eecs.wsu.edu; rtg@coast.ucsd.edu NR 53 TC 201 Z9 202 U1 2 U2 28 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9275 EI 2169-9291 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD FEB 15 PY 1998 VL 103 IS C2 BP 3203 EP 3215 DI 10.1029/97JC02765 PG 13 WC Oceanography SC Oceanography GA YY122 UT WOS:000072115500029 ER PT J AU Faria, AFG Thornton, EB Stanton, TP Soares, CV Lippmann, TC AF Faria, AFG Thornton, EB Stanton, TP Soares, CV Lippmann, TC TI Vertical profiles of longshore currents and related bed shear stress and bottom roughness SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID CALIFORNIA CONTINENTAL-SHELF; BOUNDARY-LAYER; COMBINED WAVE; RIPPLED BED; FLOW; DISSIPATION; NEARSHORE; MODEL; SAND; ENERGETICS AB The vertical structure of the mean wave-driven longshore current over a barred beach is examined on three strong current days during the DUCK94 experiment, and it is found that the bottom boundary layer is well described by a logarithmic profile (mean correlation coefficient for all 22 profiles, 0.98). The logarithmic profile fits better in the trough, where turbulent bottom boundary layer processes predominate, than over the bar, where breaking-wave-induced turbulence generated at the surface modifies the profile. The surface layer in the presence of waves is well described by adjusting the logarithmic profile for the intermittent presence of water and adding the alongshore component of the mass transport velocity (slope of the least squares linear regression between model predictions and observations, 1.005 and root-mean-square (rms) error of 7%). Bed shear stresses calculated from logarithmic velocity profiles are equated to a quadratic bottom shear stress formulation. The associated bed shear stress coefficients vary by more than an order; of magnitude across the surf zone (0.0006-0.012). Bottom roughness was measured throughout the nearshore using a sonic altimeter mounted on a moving platform. The bed shear stress coefficients are positively correlated with bottom roughness (linear correlation coefficient, 0.6). A higher linear correlation coefficient (0.8) is obtained by subtracting skin friction from the total bed shear stress. C1 USN, Postgrad Sch, Dept Oceanog, Monterey, CA 93943 USA. RP Faria, AFG (reprint author), Diretoria Hidrog & Navegacao, BR-24048 Rio De Janeiro, Brazil. NR 52 TC 64 Z9 65 U1 1 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD FEB 15 PY 1998 VL 103 IS C2 BP 3217 EP 3232 DI 10.1029/97JC02265 PG 16 WC Oceanography SC Oceanography GA YY122 UT WOS:000072115500030 ER PT J AU Deniz, AV Lehecka, T Lehmberg, RH Obenschain, SP AF Deniz, AV Lehecka, T Lehmberg, RH Obenschain, SP TI Comparison between measured and calculated nonuniformities of Nike laser beams smoothed by induced spatial incoherence SO OPTICS COMMUNICATIONS LA English DT Article ID PROFILES; FUSION; SYSTEM; ILLUMINATION; UNIFORMITY AB We have studied the spatial fluence nonuniformities in single beams from the Nike KrF laser smoothed by the Induced Spatial Incoherence (ISI) technique. This study compares time-integrated CCD camera measurements with a numerical model of ISI speckle used in the NRL FAST2D hydrocode, and with analytic calculations that examine the ensemble-ever age behavior of that model. The results verify the model and calculations, showing good agreement of both the spatial mode spectra and the total nonuniformity versus pulsewidth and bandwidth. (C) 1998 Elsevier Science B.V. C1 Sci Applicat Int Corp, Mclean, VA 22102 USA. USN, Res Lab, Div Plasma Phys, Washington, DC 20375 USA. RP Lehmberg, RH (reprint author), Sci Applicat Int Corp, MS 2-3-1,1710 Goodridge Dr, Mclean, VA 22102 USA. NR 19 TC 23 Z9 23 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 FEB 15 PY 1998 VL 147 IS 4-6 BP 402 EP 410 DI 10.1016/S0030-4018(97)00515-4 PG 9 WC Optics SC Optics GA ZL003 UT WOS:000073389100032 ER PT J AU Moriarty, RM Enache, LA Zhao, L Gilardi, R Mattson, MV Prakash, O AF Moriarty, RM Enache, LA Zhao, L Gilardi, R Mattson, MV Prakash, O TI Rigid phencyclidine analogues. Binding to the phencyclidine and sigma(1) receptors SO JOURNAL OF MEDICINAL CHEMISTRY LA English DT Article ID METHYL-D-ASPARTATE; RAT-BRAIN MEMBRANES; INDUCED NEURONAL DAMAGE; CENTRAL NERVOUS-SYSTEM; HIGH-AFFINITY BINDING; GUINEA-PIG BRAIN; ANTICONVULSANT MK-801; NMDA RECEPTOR; GLUTAMATE NEUROTOXICITY; BIOLOGICAL-ACTIVITY AB Three phencyclidine (PCP) analogues possessing a highly rigid carbocyclic structure and an attached piperidine ring which is free to rotate were synthesized. Each analogue has a specific fixed orientation of the ammonium center of the piperidinium ring to the centrum of the phenyl ring. The binding affinities of the rigid analogues 1-piperidino-7,8-benzobicyclo[4.2.0]octene (14), 1-piperidinobenzobicyclo[2.2.1]heptene (16), and 1-piperidinobenzobicyclo[2.2.2]octene (13) for the PCP receptor ([H-3]TCP) and sigma-receptor (NANM) were determined. The three analogues show low to no affinity for the PCP receptor but good affinity for the sigma-receptor and can be considered sigma-receptor selective ligands with PCP/sigma ratios of 13, 293, and 368, respectively. The binding affinities for the sigma-receptor are rationalized in terms of a model for the sigma-pharmacophore. C1 Univ Illinois, Dept Chem, Chicago, IL 60607 USA. USN, Res Lab, Struct Matter Lab, Washington, DC 20375 USA. NIDDK, Med Chem Lab, NIH, Bethesda, MD 20892 USA. RP Moriarty, RM (reprint author), Univ Illinois, Dept Chem, Chicago, IL 60607 USA. NR 95 TC 23 Z9 23 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0022-2623 J9 J MED CHEM JI J. Med. Chem. PD FEB 12 PY 1998 VL 41 IS 4 BP 468 EP 477 DI 10.1021/jm970059p PG 10 WC Chemistry, Medicinal SC Pharmacology & Pharmacy GA YX340 UT WOS:000072030400007 PM 9484497 ER PT J AU Carslaw, KS Wirth, M Tsias, A Luo, BP D"rnbrack, A Leutbecher, M Volkert, H Renger, W Bacmeister, JT Reimer, E Peter, T AF Carslaw, KS Wirth, M Tsias, A Luo, BP Drnbrack, A Leutbecher, M Volkert, H Renger, W Bacmeister, JT Reimer, E Peter, T TI Increased stratospheric ozone depletion due to mountain-induced atmospheric waves SO NATURE LA English DT Article ID 1988/89 ARCTIC WINTER; TEMPERATURE-FLUCTUATIONS; CHLORINE; SIMULATION; MODEL AB Chemical reactions on polar stratospheric cloud (PSC) particles are responsible for the production of reactive chlorine species (chlorine 'activation') which cause ozone destruction(1). Gas-phase deactivation of these chlorine species can take several weeks in the Arctic winter stratosphere, so that ozone destruction can be sustained even in air parcels that encounter PSCs only intermittently(2,3). Chlorine activation during a PSC encounter proceeds much faster at low temperatures when cloud particle surface area and heterogeneous reaction rates are higher(4). Although mountain-induced atmospheric gravity waves are known to cause local reductions in stratospheric temperature of as much as 10-15 K (refs 5-9), and are often associated with mesoscale PSCs10-12, their effect on chlorine activation and ozone depletion has not been considered. Here we describe aircraft observations of mountain-wave-induced mesoscale PSCs in which temperatures were 12 K lower than expected synoptically, Model calculations show that despite their localized nature, these PSCs can cause almost complete conversion of inactive chlorine species to ozone-destroying forms in air flowing through the clouds. Using a global mountain-wave model(8), we identify regions where mountain waves can develop, and show that they can cause frequent chlorine activation of air in the Arctic stratosphere. Such mesoscale processes offer a possible explanation for the underprediction of reactive chlorine concentrations and ozone depletion rates calculated by three-dimensional models of the Arctic stratosphere(13-17). C1 Max Planck Inst Chem, D-55128 Mainz, Germany. DLR, D-32230 Wessling, Germany. USN, Res Lab, Washington, DC 20375 USA. Inst Meteorol, D-12165 Berlin 41, Germany. RP Carslaw, KS (reprint author), Max Planck Inst Chem, Postfach 3060, D-55128 Mainz, Germany. EM carslaw@mpch-mainz.mpg.de RI Volkert, Hans/A-7041-2013; Carslaw, Ken/C-8514-2009 OI Volkert, Hans/0000-0003-1688-208X; Carslaw, Ken/0000-0002-6800-154X NR 27 TC 149 Z9 150 U1 1 U2 12 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD FEB 12 PY 1998 VL 391 IS 6668 BP 675 EP 678 DI 10.1038/35589 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA YW872 UT WOS:000071982500046 ER PT J AU Gorny, MK Mascola, JR Israel, ZR VanCott, TC Williams, C Balfe, P Hioe, C Brodine, S Burda, S Zolla-Pazner, S AF Gorny, MK Mascola, JR Israel, ZR VanCott, TC Williams, C Balfe, P Hioe, C Brodine, S Burda, S Zolla-Pazner, S TI A human monoclonal antibody specific for the V3 loop of HIV type 1 clade E cross-reacts with other HIV type 1 clades SO AIDS RESEARCH AND HUMAN RETROVIRUSES LA English DT Article ID HUMAN-IMMUNODEFICIENCY-VIRUS; NEUTRALIZATION SEROTYPES; ENVELOPE GLYCOPROTEIN; VIRAL GENOTYPE; SUBTYPE-E; GP120; ASSAY; CELL; BINDING; SENSITIVITY AB To ascertain the antigenic relationship between HIV-1 viruses belonging to various genetically defined subgroups (clades), shared epitopes need to be defined, Human monoclonal antibodies (MAbs) are particularly useful for this purpose because they can detect complex regions of viral proteins that may be missed by sequence analysis and because, by definition, they react with epitopes that stimulate the human immune system, Monoclonal antibodies derived from the cells of HIV-1 clade B-infected subjects have been used extensively for this purpose, Here we describe the first human MAb derived from a clade E-infected individual; the MAb is specific for the V3 loop, recognizing a core epitope represented by the amino acids TRTSVR on the N-terminal side of the crown of the V3 loop, The IgG(1)(kappa) MAb, designated 1324E, binds to the clade E consensus V3 loop, to rgp120 proteins from clade E and to peripheral blood mononuclear cells infected in vitro with the virus that infected the subject from whose cells the MAb-producing heterohybridoma was derived, Strong cross-reactivity of the MAb to the V3 peptides, rgp120 proteins, and native monomeric gp120s representing clades A and C, as well as to cells infected with a clade C primary isolate, revealed a shared V3 epitope between these clades, When tested for its neutralizing ability, MAb 1324E neutralized a clade E isolate that had been adapted for growth in H9 cells but failed to neutralize five clade E primary isolates. C1 Vet Affairs Med Ctr, New York, NY 10010 USA. NYU, Med Ctr, New York, NY 10016 USA. Walter Reed Army Inst Res, Rockville, MD 20850 USA. USN, Inst Med Res, Rockville, MD 20850 USA. Henry M Jackson Fdn, Rockville, MD 20850 USA. UCL, Sch Med, London, England. USN, Hlth Res Ctr, San Diego, CA 92186 USA. RP Zolla-Pazner, S (reprint author), Vet Affairs Med Ctr, 423 E 23rd St,Room 18124N, New York, NY 10010 USA. OI Gorny, Miroslaw/0000-0002-2714-8780 FU NIAID NIH HHS [AI 32424, AI 36085, AI 07382] NR 41 TC 22 Z9 22 U1 0 U2 0 PU MARY ANN LIEBERT INC PI NEW ROCHELLE PA 140 HUGUENOT STREET, 3RD FL, NEW ROCHELLE, NY 10801 USA SN 0889-2229 J9 AIDS RES HUM RETROV JI Aids Res. Hum. Retrovir. PD FEB 10 PY 1998 VL 14 IS 3 BP 213 EP 221 DI 10.1089/aid.1998.14.213 PG 9 WC Immunology; Infectious Diseases; Virology SC Immunology; Infectious Diseases; Virology GA YW536 UT WOS:000071946200004 PM 9491911 ER PT J AU Spicer, DS Feldman, U Widing, KG Rilee, M AF Spicer, DS Feldman, U Widing, KG Rilee, M TI The neon-to-magnesium abundance ratio as a tracer of the source region of prominence material SO ASTROPHYSICAL JOURNAL LA English DT Article DE Sun, abundances; Sun, corona; Sun, magnetic fields; Sun, prominences AB A survey of all 1000 spectroheliograms in the Skylab spectroheliograph plate collection was made to identify prominences above the limb and prominence-like features. The Ne/Mg abundance ratios obtained from the measurements have been determined from relative intensities of Ne VI and Mg VI lines at 400 Angstrom of seven prominences and prominence-like features observed above the solar limb. The derived abundance ratios have values intermediate between the photosphere and corona, while none are as low as the ratio of 0.7 expected in the corona, which implies that the material found in prominences is photospheric in origin. The significance of these results for the formation of prominences is briefly discussed. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. USN, Res Lab, EO Hulburt Ctr Space Res, Washington, DC 20735 USA. RP Spicer, DS (reprint author), NASA, Goddard Space Flight Ctr, Code 930, Greenbelt, MD 20771 USA. NR 6 TC 15 Z9 15 U1 0 U2 0 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 10 PY 1998 VL 494 IS 1 BP 450 EP + DI 10.1086/305203 PN 1 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA YY520 UT WOS:000072155800037 ER PT J AU Campbell, ML AF Campbell, ML TI Gas-phase kinetics of ground-state platinum with O-2, NO, N2O and CH4 SO JOURNAL OF THE CHEMICAL SOCIETY-FARADAY TRANSACTIONS LA English DT Article ID TRANSITION-METAL ATOMS; EXOTHERMIC HOMOLOGOUS REACTIONS; ACTIVATION BARRIERS; OXIDATION REACTIONS; ROOM-TEMPERATURE; LINEAR ALKANES; CHROMIUM ATOMS; COPPER ATOMS; ALKENES; REACTIVITY AB The gas-phase reactivity of ground-state platinum with O-2, NO, N2O and CH4 is reported. Platinum atoms were produced by the photodissociation of [Pt(CH3)(3)(C5H4CH3)] and detected by laser-induced fluorescence. The reaction rates of platinum with all the reactants are pressure dependent indicating adduct formation; however, the reaction with N2O has a bimolecular component. The room-temperature limiting low-pressure third-order rate constants in argon buffer are (2.3 +/- 0.2) x 10(-31) molecule(-2) cm(6) s(-1), (4.3 +/- 0.4) x 10(-31) molecule(-2) cm(6) s(-1), (3.7 +/- 0.5) x 10(-31) molecule(-2) cm(6) s(-1) and (2.1 +/- 0.9) x 10(-28) molecule(-2) cm(6) s(-1) for O-2, NO, N2O and CH4, respectively, where the uncertainties are +/-2 sigma. The limiting high-pressure second-order rate constants are (2.5 +/- 0.5) x 10(-12) molecule(-1) cm(3) s(-1), (2.3 +/- 0.8) x 10(-11) molecule(-1) cm(3) s(-1), (2.3 +/- 0.3) x 10(-12) molecule(-1) cm(3) s(-1) and (6.3 +/- 0.3) x 10(-12) molecule(-1) cm(3) s(-1) for O-2, NO, N2O and CH4, respectively. The second-order rate constant for the abstraction channel for the reaction with N2O at 296 K is approximately 1 x 10(-13) molecule(-1) cm(3) s(-1). C1 USN Acad, Dept Chem, Annapolis, MD 21402 USA. RP Campbell, ML (reprint author), USN Acad, Dept Chem, Annapolis, MD 21402 USA. NR 60 TC 25 Z9 25 U1 0 U2 1 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON ROAD, CAMBRIDGE CB4 4WF, CAMBS, ENGLAND SN 0956-5000 J9 J CHEM SOC FARADAY T JI J. Chem. Soc.-Faraday Trans. PD FEB 7 PY 1998 VL 94 IS 3 BP 353 EP 358 DI 10.1039/a705892f PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA YW963 UT WOS:000071992300002 ER PT J AU Yang, MJ Moore, WJ Bennett, BR Shanabrook, BV AF Yang, MJ Moore, WJ Bennett, BR Shanabrook, BV TI Growth and characterisation of InAs/InGaSb/InAs/AlSb infrared laser structures SO ELECTRONICS LETTERS LA English DT Article ID QUANTUM-WELL LASERS; SUPERLATTICES AB The authors have studied the molecular-beam epitaxial growth of type-II heterostructures for mid-wavelength infrared lasers. Based on their photoluminescence spectra and X-ray diffraction patterns, it is found that the quality of these heterostructures is highly sensitive to the growth temperature and the interfacial bond type. C1 USN, Res Lab, Washington, DC 20375 USA. RP Yang, MJ (reprint author), USN, Res Lab, Washington, DC 20375 USA. RI Bennett, Brian/A-8850-2008 OI Bennett, Brian/0000-0002-2437-4213 NR 10 TC 37 Z9 38 U1 0 U2 10 PU IEE-INST ELEC ENG PI HERTFORD PA MICHAEL FARADAY HOUSE SIX HILLS WAY STEVENAGE, HERTFORD SG1 2AY, ENGLAND SN 0013-5194 J9 ELECTRON LETT JI Electron. Lett. PD FEB 5 PY 1998 VL 34 IS 3 BP 270 EP 272 DI 10.1049/el:19981221 PG 3 WC Engineering, Electrical & Electronic SC Engineering GA YY494 UT WOS:000072152200032 ER PT J AU Campbell, ML AF Campbell, ML TI Kinetic study of the reaction of Re(a(6)S(5/2)) with O-2, NO, N2O, and CH4 SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID TRANSITION-METAL ATOMS; EXOTHERMIC HOMOLOGOUS REACTIONS; GAS-PHASE REACTIONS; ACTIVATION BARRIERS; OXIDATION REACTIONS; ROOM-TEMPERATURE; LINEAR ALKANES; CHROMIUM ATOMS; COPPER ATOMS; CU ATOMS AB The gas-phase reactivity of ground-state Re(a(6)S(5/2)) with O-2, NO, N2O, and CH4 is reported. Rhenium atoms were produced by the photodissociation of Re(CO)(5)Cl and detected by laser-induced fluorescence. The reaction rate of the a(6)S(5/2) state with O-2 is slow and temperature-dependent. The reaction is pressure-independent, indicating a bimolecular abstraction reaction. The bimolecular rate constant from 296 to 548 K is described in Arrhenius form by (2.1 +/- 0.3) x 10(-11) exp(-11.6 +/- 0.6 kJ/mol/RT) where the uncertainties represent +/- 2 sigma. The reaction rate of the a(6)S(5/2) state-with NO is pressure-dependent, indicating adduct formation. The limiting low-pressure third-order, k(0), and limiting high-pressure second-order, k(infinity), room-temperature rate constants with NO in nitrogen buffer are (3.7 +/- 0.8) x 10(-30) cm(6) s(-1) and (7.0 +/- 0.8) x 10(-12) cm(3) s(-1), respectively. There is no evidence of chemical reaction for the ground state of rhenium with N2O or CH4 up to a temperature of 548 K. C1 USN Acad, Dept Chem, Annapolis, MD 21402 USA. RP Campbell, ML (reprint author), USN Acad, Dept Chem, Annapolis, MD 21402 USA. NR 53 TC 17 Z9 17 U1 1 U2 1 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 5 PY 1998 VL 102 IS 6 BP 892 EP 896 DI 10.1021/jp9725846 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA YW472 UT WOS:000071939100003 ER PT J AU Zhang, Y Kong, JA Jordan, AK AF Zhang, Y Kong, JA Jordan, AK TI Inversion of arbitrary electromagnetic scattering data to reconstruct the scattering potential of a plasma medium SO MICROWAVE AND OPTICAL TECHNOLOGY LETTERS LA English DT Article DE inverse scattering; GLM integral equation; plasma layer AB A numerical method using matrix inversion has been generalized to solve the Gel'fand-Levitan-Marchenko (GLM) inverse scattering problem for arbitrary forms of reflection coefficient data for plasma medium. An accurate representation of the reflection transient was calculated using the Gauss-Legendre method with a small number of sampling data points of the reflection coefficient. The reflection coefficient has also been derived in a closed form for a uniform plasma layer, and the inversion result accurately reconstructed the original profile. The algorithm can also be applied to reconstruct the 1-D profile for inhomogeneous plasma medium from measured reflection coefficient data. (C) 1998 John Wiley & Sons, Inc. C1 MIT, Dept Elect Engn & Comp Sci, Cambridge, MA 02139 USA. USN, Res Lab, Remote Sensing Div, Washington, DC 20375 USA. RP Zhang, Y (reprint author), MIT, Dept Elect Engn & Comp Sci, Cambridge, MA 02139 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0895-2477 J9 MICROW OPT TECHN LET JI Microw. Opt. Technol. Lett. PD FEB 5 PY 1998 VL 17 IS 2 BP 97 EP 101 PG 5 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA YR254 UT WOS:000071476400007 ER PT J AU Krowne, CM AF Krowne, CM TI 2-D cross-coupling recursive dyadic Green's function, circuit parameters, and fields for radially inhomogeneous microstrip circular ferrite circulator SO MICROWAVE AND OPTICAL TECHNOLOGY LETTERS LA English DT Article DE microstrip circulator; dyadic Green's function; inhomogeneous ferrite; electromagnetic fields; two dimensional ID DISK CIRCULATOR AB EH and HH dyadic Green's function elements are presented, streamlined recursive equations are given in matrix form, circuit impedances and admittances are derived for arbitrarily placed ports, and magnetic field expressions are derived which can be used in contour plotting for an inhomogeneous microstrip circular ferrite circulator. (C) 1998 John Wiley & Sons, Inc. C1 USN, Res Lab, Div Elect Sci & Technol, Microwave Technol Branch, Washington, DC 20375 USA. RP Krowne, CM (reprint author), USN, Res Lab, Div Elect Sci & Technol, Microwave Technol Branch, Washington, DC 20375 USA. NR 5 TC 1 Z9 1 U1 0 U2 0 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0895-2477 J9 MICROW OPT TECHN LET JI Microw. Opt. Technol. Lett. PD FEB 5 PY 1998 VL 17 IS 2 BP 140 EP 148 DI 10.1002/(SICI)1098-2760(19980205)17:2<140::AID-MOP17>3.0.CO;2-C PG 9 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA YR254 UT WOS:000071476400017 ER PT J AU McKeown, MJ Jung, TP Makeig, S Brown, G Kindermann, SS Lee, TW Sejnowski, TJ AF McKeown, MJ Jung, TP Makeig, S Brown, G Kindermann, SS Lee, TW Sejnowski, TJ TI Spatially independent activity patterns in functional MRI data during the Stroop color-naming task SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article; Proceedings Paper CT Colloquium on Neuroimaging of Human Brain Function CY MAY 29-31, 1997 CL ARNOLD & MABEL BECKMAN CTR, IRVINE, CALIFORNIA SP Natl Acad Sci HO ARNOLD & MABEL BECKMAN CTR ID HEAD-INJURY; DATA SETS; ACTIVATION; BRAIN; PET AB A method is given for determining the time course and spatial extent of consistently and transiently task-related activations from other physiological and artifactual components that contribute to functional MRI (fMRI) recordings. Independent component analysis (ICA) was used to analyze two fMRI data sets from a subject performing 6-min trials composed of alternating 40-sec Stroop color-naming and control task blocks, Each component consisted of a fixed three-dimensional spatial distribution of brain voxel values (a "map") and an associated time course of activation, For each trial, the algorithm detected, without a priori knowledge of their spatial or temporal structure, one consistently task-related component activated during each Stroop task block, plus several transiently task-related components activated at the onset of one or two of the Stroop task blocks only, Activation patterns occurring during only part of the fMRI trial are not observed with other techniques, because their time courses cannot easily be known in advance, Other ICA components were related to physiological pulsations, head movements, or machine noise, By using higher-order statistics to specify stricter criteria for spatial independence between component maps, ICA produced improved estimates of the temporal and spatial extent of task-related activation in our data compared with principal component analysis (PCA), ICA appears to be a promising tool for exploratory analysis of fMRI data, particularly when the time courses of activation are not known in advance. C1 Salk Inst Biol Studies, Computat Neurobiol Lab, Howard Hughes Med Inst, La Jolla, CA 92086 USA. USN, Hlth Res Ctr, San Diego, CA 92186 USA. Univ Calif San Diego, Sch Med, Dept Neurosci, La Jolla, CA 92093 USA. Univ Calif San Diego, Sch Med, Dept Psychiat, La Jolla, CA 92093 USA. Univ Calif San Diego, Dept Biol, La Jolla, CA 92093 USA. RP McKeown, MJ (reprint author), Salk Inst Biol Studies, Computat Neurobiol Lab, 10010 N Torrey Pines Rd, La Jolla, CA 92037 USA. NR 27 TC 298 Z9 308 U1 2 U2 13 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD FEB 3 PY 1998 VL 95 IS 3 BP 803 EP 810 DI 10.1073/pnas.95.3.803 PG 8 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA YV928 UT WOS:000071878500007 PM 9448244 ER PT J AU Ding, YJ Korotkov, R Khurgin, JB Rabinovich, WS Katzer, DS AF Ding, YJ Korotkov, R Khurgin, JB Rabinovich, WS Katzer, DS TI Observation of an anomalously large blueshift of apparent donor-acceptor pair transition peak in compensation-doped quantum wells SO APPLIED PHYSICS LETTERS LA English DT Article ID PHOTOLUMINESCENCE AB Wt have observed an anomalously large blueshift of the apparent donor-acceptor pair transition peak as the laser intensity increases in compensation-doped coupled quantum wells. The mechanism for the blueshift is the change of the Coulomb interaction energy between the recombined donors and accepters due to the decrease in their separation as the laser intensity increases. The blueshift is accompanied by the saturation of the relative donor-acceptor pair transition peak intensity due to filling of the impurity states. (C) 1998 American Institute of Physics. C1 Bowling Green State Univ, Ctr Mat, Dept Phys & Astron, Bowling Green, OH 43403 USA. Bowling Green State Univ, Ctr Photochem Sci, Bowling Green, OH 43403 USA. Johns Hopkins Univ, Dept Elect & Comp Engn, Baltimore, MD 21218 USA. USN, Res Lab, Washington, DC 20375 USA. RP Ding, YJ (reprint author), Bowling Green State Univ, Ctr Mat, Dept Phys & Astron, Bowling Green, OH 43403 USA. RI khurgin, Jacob/A-3278-2010; Katzer, D. Scott/N-7841-2013 NR 14 TC 5 Z9 5 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 FEB 2 PY 1998 VL 72 IS 5 BP 534 EP 536 DI 10.1063/1.120812 PG 3 WC Physics, Applied SC Physics GA YU312 UT WOS:000071704700008 ER PT J AU Ngai, KL Greaves, GN Moynihan, CT AF Ngai, KL Greaves, GN Moynihan, CT TI Correlation between the activation energies for ionic conductivity for short and long time scales and the Kohlrausch stretching parameter beta for ionically conducting solids and melts SO PHYSICAL REVIEW LETTERS LA English DT Article ID NON-ARRHENIUS CONDUCTIVITY; LITHIUM BORATE GLASSES; ELECTRICAL RELAXATION; NEUTRON-SCATTERING; MOBILE IONS; TRANSPORT; EXPLANATION; DIFFUSION; ALUMINA; MODEL AB The temperature dependence of the dc conductivity sigma of most glass-forming and crystalline ionic conductors is Arrhenius with constant activation energy, E-sigma, at sufficiently low temperatures or conductivity levels. However, sigma becomes non-Arrhenius at high temperatures or conductivity levels. We have round that the product, beta E-sigma, of the Kohlrausch stretching exponent for the conductivity relaxation, beta, and the dc conductivity activation energy in the Arrhenius regime is approximately the same as the high temperature apparent activation energy, E-a, of sigma at the temperature where sigma reaches the high level or 1 Ohm(-1) cm(-1) and the conductivity relaxation time tau(sigma) is of the order of 1 psec. C1 USN, Res Lab, Washington, DC 20375 USA. Univ Wales, Dept Phys, Aberystwyth SY23 3BZ, Ceredigion, Wales. Rensselaer Polytech Inst, Dept Mat Sci & Engn, Troy, NY 12180 USA. RP Ngai, KL (reprint author), USN, Res Lab, Washington, DC 20375 USA. NR 53 TC 87 Z9 88 U1 0 U2 11 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 FEB 2 PY 1998 VL 80 IS 5 BP 1018 EP 1021 DI 10.1103/PhysRevLett.80.1018 PG 4 WC Physics, Multidisciplinary SC Physics GA YU675 UT WOS:000071742600032 ER PT J AU Simmons, M Porter, KR Escamilla, J Graham, R Watts, DM Eckels, KH Hayes, CG AF Simmons, M Porter, KR Escamilla, J Graham, R Watts, DM Eckels, KH Hayes, CG TI Evaluation of recombinant dengue viral envelope B domain protein antigens for the detection of dengue complex-specific antibodies SO AMERICAN JOURNAL OF TROPICAL MEDICINE AND HYGIENE LA English DT Article ID LINKED IMMUNOSORBENT-ASSAY; IMMUNOLOGICAL MEMORY; ELISA; INFECTIONS; IGG AB To increase the specificity of dengue (DEN) diagnosis based on antibody detection, we have evaluated recombinant proteins as antigens that incorporate most of the B domain of the DEN virus envelope protein fused to the trpE protein of Escherichia coli (trpE-DEN). A pooled antigen consisting of trpE-DEN proteins representing all four serotypes of DEN virus was used in an indirect ELISA for the detection of IgG or IgM antibody. This assay was compared with a standard IgG indirect ELISA and an IgM-capture ELISA using DEN virus-infected cell culture pooled antigens. The results indicated that the trpE-DEN antigens and the cell culture antigens were equally sensitive for detecting IgM and IgG antibodies in convalescent sera from Peru and Indonesia representing virus isolation-confirmed primary and secondary DEN infections, respectively. Fourteen day postinfection IgG antibody-positive sera obtained from individuals infected with DEN-1 virus who had been vaccinated with other flaviviruses were more strongly reactive with the cell culture antigen than with the recombinant antigen, but by day 21 postinfection, a strong antibody response to the trpE-DEN antigens was present. These results suggested that the early antibody response was directed predominantly towards shared flavivirus group antigens that were not detected with the trpE-DEN antigens. Comparison of the trpE-DEN-1 recombinant antigen with a DEN-1 virus-infected cell lysate antigen for the detection of IgG antibody in sera from a cohort of 55 individuals from Peru who seroconverted over a one-year period indicated greater specificity for the recombinant antigens. Also, sera from individuals with no known DEN infections that had been sequentially vaccinated with yellow fever and Japanese encephalitis reacted with the DEN virus cell culture antigen in the IgG ELISA, but did not react with the trpE-DEN pooled antigens. Similarly, YF IgM antibody positive samples that showed cross-reactivity with the DEN virus cell. culture antigens, did not react with the trpE-DEN pooled antigens. These results indicated that the trpE-DEN pooled antigen provided a more specific diagnosis of dengue infections than DEN virus-infected cell culture antigen and avoided the biohazards associated with handling live virus during the preparation of diagnostic reagents. The trpE-DEN pooled antigen should permit a better approach to distinguish between past DEN and other flavivirus infections in epidemiologic surveys, and also increase the specificity of serologic diagnosis of acute DEN infections. C1 USN, Med Res Inst, Dept Infect Dis, Bethesda, MD 20889 USA. USN, Ctr Environm Hlth, Norfolk, VA 23513 USA. Walter Reed Army Inst Res, Dept Biol Res, Washington, DC 20307 USA. USN, Med Res Unit 2, Jakarta, Indonesia. USN, Med Res Inst Detachment, Lima, Peru. RP Simmons, M (reprint author), USN, Med Res Inst, Dept Infect Dis, Code 4121,8901 Wisconsin Ave, Bethesda, MD 20889 USA. NR 24 TC 23 Z9 26 U1 0 U2 2 PU AMER SOC TROP MED & HYGIENE PI MCLEAN PA 8000 WESTPARK DRIVE SUITE 130, MCLEAN, VA 22101 USA SN 0002-9637 J9 AM J TROP MED HYG JI Am. J. Trop. Med. Hyg. PD FEB PY 1998 VL 58 IS 2 BP 144 EP 151 PG 8 WC Public, Environmental & Occupational Health; Tropical Medicine SC Public, Environmental & Occupational Health; Tropical Medicine GA YZ465 UT WOS:000072256800006 PM 9502595 ER PT J AU Zukowski, M Lord, J Ash, K Shouse, B Getz, S Robb, G AF Zukowski, M Lord, J Ash, K Shouse, B Getz, S Robb, G TI The gracilis free flap revisited: A review of 25 cases of transfer to traumatic extremity wounds SO ANNALS OF PLASTIC SURGERY LA English DT Article ID FREE-TISSUE TRANSFER; MUSCULOCUTANEOUS FLAP; LIMB SALVAGE; FOOT; REVASCULARIZATION AB Trauma to the extremities often results in a complex bony and soft-tissue injury requiring free flap reconstruction, Muscles from various body sites have been used in extremity reconstruction since the early 1970s, The gracilis muscle is usually not considered the first choice for free flap reconstruction of these defects. It is usually relegated to small defects or used to reanimate the face, Our purpose is to present our experience with the gracilis muscle as a first-choice flap in reconstruction of traumatic extremity defects, A retrospective review of all gracilis muscle free flap transfers for traumatic extremity wounds between 1988 and 1995 at the Naval Medical Center Portsmouth was performed, Twenty-five patients age 20 to 71 years (mean, 29.7 years) underwent 26 free flaps to the lower leg, ankle, foot, or forearm to cover traumatic wounds. Defects ranged in size from 3 x 3 cm (9 cm(2)) to 13 X 18 cm (234 cm(2)), with a mean of 75.5 cm(2). There were no flap losses and all wounds healed, Nine patients experienced 11 complications, which consisted of minor wound separation (16%), wound infection (12%), partial or complete loss of split-thickness skin graft (8%), thrombosis of graft with successful revascularization (4%), and nonunion of an underlying fracture (4%). Our overall success rate for gracilis free flap reconstruction of traumatic wounds is 100%, The gracilis free muscle flap has become our first option for tissue coverage in traumatized extremities, It leaves minimal functional defect limited to the side of the primary injury and provides a good cosmetic result, It can cover large defects when the epimysium is cut, and allows an epidural block to be performed for sympathectomy effect and pain control in the affected extremity during the immediate postoperative period. C1 USN, Med Ctr, Dept Plast & Reconstruct Surg, Portsmouth, VA USA. USN, Med Ctr, Dept Gen Surg, Portsmouth, VA USA. RP Zukowski, M (reprint author), Zukowski Ctr Cosmet Plast Surg, 3612 W Lake Ave, Wilmette, IL 60091 USA. NR 15 TC 20 Z9 20 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 USA SN 0148-7043 J9 ANN PLAS SURG JI Ann. Plast. Surg. PD FEB PY 1998 VL 40 IS 2 BP 141 EP 144 DI 10.1097/00000637-199802000-00006 PG 4 WC Surgery SC Surgery GA YV537 UT WOS:000071835000006 PM 9495461 ER PT J AU Lucke, RL Thonnard, SE AF Lucke, RL Thonnard, SE TI Stacked-grid collimators described with dimensionless parameters SO APPLIED OPTICS LA English DT Article AB The properties of a one-dimensional stacked-grid collimator can be specified by two dimensionless parameters. This is useful because a two-dimensional collimator can usually be described as two one-dimensional collimators. Plots are given that show normal-incidence transmission and FWHM angular response in terms of these parameters. Transmission is calculated with Fourier optics instead of the Fresnel-Kirchhoff integral. C1 USN, Res Lab, Washington, DC 20375 USA. RP Lucke, RL (reprint author), USN, Res Lab, Washington, DC 20375 USA. NR 14 TC 5 Z9 5 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 1 PY 1998 VL 37 IS 4 BP 616 EP 621 DI 10.1364/AO.37.000616 PG 6 WC Optics SC Optics GA YV841 UT WOS:000071868700002 PM 18268631 ER PT J AU Seltzer, MD AF Seltzer, MD TI Continuous air monitoring using inductively coupled plasma atomic emission spectrometry: Correction of spectral interferences arising from CN emission SO APPLIED SPECTROSCOPY LA English DT Article DE continuous air monitoring; air pollutant metals; atomic emission spectrometry; spectral interferences AB Introduction of sample stream air into an argon inductively coupled plasma permits continuous monitoring of hazardous air pollutant metals in combustion flue gases. Along with entrained particulates and metal vapors, various molecular components of the hue gas are introduced into the plasma. These species, and reaction products thereof, also undergo excitation resulting in complex emission spectra of appreciable intensity. Serious spectral interferences arise for several metal elements, from molecular emission bands associated with the stable CN radical and other polyatomic species. Failure to account for these interferences can significantly degrade accuracy particularly at low flue gas metal concentrations. Reported here is an effective method for measurement and correction of CN spectral interferences affecting the on-line detection of hazardous air pollutant metals that incorporates conventional polychromator hardware and existing instrument software capabilities. A demonstration of the ability of this method to achieve virtually complete correction of these interferences under both laboratory and field conditions is presented. C1 USN, Res & Technol Grp, Air Warfare Ctr, Weap Div, China Lake, CA 93555 USA. RP Seltzer, MD (reprint author), USN, Res & Technol Grp, Air Warfare Ctr, Weap Div, Code 4B2300D, China Lake, CA 93555 USA. NR 7 TC 21 Z9 23 U1 0 U2 1 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 195 EP 199 DI 10.1366/0003702981943482 PG 5 WC Instruments & Instrumentation; Spectroscopy SC Instruments & Instrumentation; Spectroscopy GA ZF981 UT WOS:000072952600006 ER PT J AU Ross, EV Naseef, G Lin, C Kelly, M Michaud, N Flotte, TJ Raythen, J Anderson, RR AF Ross, EV Naseef, G Lin, C Kelly, M Michaud, N Flotte, TJ Raythen, J Anderson, RR TI Comparison of responses of tattoos to picosecond and nanosecond Q-switched neodymium : YAG lasers SO ARCHIVES OF DERMATOLOGY LA English DT Article; Proceedings Paper CT 16th Annual Meeting of the American-Society-for-Laser-Medicine-and-Surgery CY APR 16-17, 1996 CL ORLANDO, FLORIDA SP Amer Soc Laser Med & Surg ID DOSE-RESPONSE; RUBY-LASER AB Objective: To test the hypothesis that picosecond laser pulses are more effective than nanosecond domain pulses in clearing of tattoos. Design: Intratattoo comparison trial of 2 laser treatment modalities. Setting: A large interdisciplinary biomedical laser laboratory on the campus of a tertiary medical center. Patients: Consecutive patients with black tattoos were enrolled; all 16 patients completed the study. Intervention: We treated designated parts of the same tattoo with 35-picosecond and 10-nanosecond pulses from 2 neodymium:YAG lasers. Patients received a total of 4 treatments at 4-week intervals. All laser pulse parameters were held constant except pulse duration. Radiation exposure was 0.65 J/cm(2) at the skin surface. Biopsies were performed for routine microscopic and electron microscopic analysis at the initial treatment session and 4 weeks after the final treatment in 8 consenting patients. Also, ink samples were irradiated in vitro. Main Outcome Measures: In vivo, on the completion of treatment, a panel of dermatologists not associated with the study (and blinded to the treatment type) evaluated photographs to assess tattoo lightening. Formalin-fixed specimens were examined for qualitative epidermal and dermal changes as well as depth of pigment alteration. Electron micrographs were examined for particle electron density and size changes (in vivo and in vitro). The gross in vitro optical density changes were measured. Results: In 12 of 16 tattoos, there was significant lightening in the picosecond-treated areas compared with those treated with nanosecond pulses. Mean depth of pigment alteration was greater for picosecond pulses, but the difference was not significant. In vitro biopsy specimens showed similar electron-lucent changes for both pulse durations. In vitro results were similar for both pulse durations, showing increases in particle sizes and decreased electron density as well as gross ink lightening. Conclusions: Picosecond pulses are more efficient than nanosecond pulses in clearing black tattoos. Black tattoos clear principally by laser-induced changes in the intrinsic optical properties of the ink. C1 Harvard Univ, Massachusetts Gen Hosp, Sch Med, Dept Dermatol,Wellman Labs Photomed, Boston, MA USA. RP Ross, EV (reprint author), USN, Med Ctr, Dept Clin Res, 34800 Bob Wilson Dr, San Diego, CA 92134 USA. NR 12 TC 56 Z9 56 U1 2 U2 4 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 FEB PY 1998 VL 134 IS 2 BP 167 EP 171 DI 10.1001/archderm.134.2.167 PG 5 WC Dermatology SC Dermatology GA YX017 UT WOS:000071998000004 ER PT J AU Stout, JC Ellis, RJ Jernigan, TL Archibald, SL Abramson, I Wolfson, T McCutchan, JA Wallace, MR Atkinson, JH Grant, I AF Stout, JC Ellis, RJ Jernigan, TL Archibald, SL Abramson, I Wolfson, T McCutchan, JA Wallace, MR Atkinson, JH Grant, I CA HIV Neurobehav Res Ctr Grp TI Progressive cerebral volume loss in human immunodeficiency virus infection - A longitudinal volumetric magnetic resonance imaging study SO ARCHIVES OF NEUROLOGY LA English DT Article ID AIDS DEMENTIA COMPLEX; CENTRAL-NERVOUS-SYSTEM; HIV-INFECTION; HIV-1-INFECTED INDIVIDUALS; CEREBROSPINAL-FLUID; BRAIN ATROPHY; ASSOCIATION; ZIDOVUDINE; DISEASE AB Objective: To compare rates and anatomical patterns of brain atrophy during 3 stages of human immunodeficiency virus (HIV) disease. Design: Comparisons of multiple serial brain magnetic resonance images in men without HIV infection and HIV-infected men in Centers for Disease Control and Prevention (CDC, Atlanta, Ga) stages A, B, and C. Setting: Longitudinal cohort study of the San Diego HIV Neurobehavioral Research Center, San Diego, Calif. Participants: Eighty-six HIV-l-positive (HIV-positive) and 23 HIV-negative men who were similar in age and risk group. The number of HIV-positive men in each CDC stage was as follows: A, 33; B, 19; C, 34. All HIV-positive men were free of clinically detectable opportunistic neurologic illness. Main Outcome Measures: Regional volumes of serial magnetic resonance images converted to standardized slope estimates of change in regional volumes of interest. Results: Medically asymptomatic men (CDC stage A) and medically symptomatic men (CDC stage C) had more rapid loss of cortical tissues than did HIV-negative men as manifested by higher slopes (Tukey honestly significant difference test, P=.02 and P=.001, respectively) for cortical fluid volume. Accelerated ventricular volume enlargement occurred only in men with CDC Stage C disease. Reduction in the volume of white matter was accelerated in participants with CDC stage C disease compared with participants with CDC stage A disease. Of the gray matter regions, only the caudate nucleus sustained accelerated volume loss during CDC stage C disease. Participants whose systemic disease progressed to a higher CDC stage had significantly accelerated ventricular volume increases and caudate atrophy. Rates of cortical and subcortical fluid volume increases and reductions in the volumes of white matter and the caudate nucleus were significantly related to the rate of decline in the CD4(+) lymphocyte count. Conclusions: In the absence of cerebral opportunistic disease, HIV infection causes progressive atrophy within the gray and white matter in the brain. These changes were most severe in the most advanced stage of disease but were evident even in medically asymptomatic HIV-positive persons. Within the gray matter, the caudate nucleus exhibited progressive volume loss linked to disease stage and the rate of decline of the CD4(+) cell count. Structural brain changes can begin in the early stages of HIV infection and accelerate during advanced illness. C1 Univ Calif San Diego, Dept Psychiat, San Diego, CA 92103 USA. Univ Calif San Diego, Dept Neurosci, San Diego, CA 92103 USA. Univ Calif San Diego, Dept Math, San Diego, CA 92103 USA. Univ Calif San Diego, Dept Med, San Diego, CA 92103 USA. Dept Vet Affairs Med Ctr, San Diego, CA USA. USN, Med Ctr, San Diego, CA USA. RP Stout, JC (reprint author), Indiana Univ, Dept Psychol, Bloomington, IN 47405 USA. EM jstout@indiana.edu RI Ellis, Ronald/K-3543-2015 OI Ellis, Ronald/0000-0003-4931-752X FU NIMH NIH HHS [P50-MH45294] NR 38 TC 116 Z9 120 U1 1 U2 4 PU AMER MEDICAL ASSOC PI CHICAGO PA 515 N STATE ST, CHICAGO, IL 60610 USA SN 0003-9942 J9 ARCH NEUROL-CHICAGO JI Arch. Neurol. PD FEB PY 1998 VL 55 IS 2 BP 161 EP 168 DI 10.1001/archneur.55.2.161 PG 8 WC Clinical Neurology SC Neurosciences & Neurology GA YX019 UT WOS:000071998200003 PM 9482357 ER PT J AU Magnus, RH AF Magnus, RH TI Afghanistan in 1997 - The war moves North SO ASIAN SURVEY LA English DT Article C1 Naval Postgrad Sch, Dept Natl Secur, Monterey, CA USA. RP Magnus, RH (reprint author), Naval Postgrad Sch, Dept Natl Secur, Monterey, CA USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU UNIV CALIF PRESS PI BERKELEY PA JOURNALS DEPT 2120 BERKELEY WAY, BERKELEY, CA 94720 USA SN 0004-4687 J9 ASIAN SURV JI Asian Surv. PD FEB PY 1998 VL 38 IS 2 BP 109 EP 115 DI 10.1525/as.1998.38.2.01p0322p PG 7 WC Area Studies SC Area Studies GA ZL497 UT WOS:000073439200001 ER PT J AU Verter, F Rickard, LJ AF Verter, F Rickard, LJ TI Infrared properties of molecular cirrus. I. Photometry of extended sources on IRAS image products SO ASTRONOMICAL JOURNAL LA English DT Article DE infrared radiation; ISM, clouds; ISM, molecules ID HIGH GALACTIC LATITUDE; 100 MICRON CIRRUS; SPECTROSCOPIC ANALYSIS; PHYSICAL CONDITIONS; DUST CLOUD; EMISSION; SEARCH; STARS; GAS; DISTANCES AB We have conducted a survey of IRAS images of the high-latitude molecular cirrus clouds cataloged by Magnani, Blitz, & Mundy. This paper reports the data reduction methods used in our survey and also studies the photometric accuracy that can be achieved for faint extended sources on IRAS image products. The principal topics covered are the modeling and removal of sky backgrounds at high Galactic latitude, and as a function of ecliptic latitude; the relative accuracy of different background models and methods of background removal; the integration of source flux on background-subtracted images; the proper definition of flux error bars, their calculation, and the minimum uncertainties set by the performance of the IRAS detectors; the creation of multiple-wavelength composite images; and the creation of temperature and opacity maps. We find that most error bars quoted for IRAS fluxes in the literature are incorrect. We conclude that the limiting surface brightness to which Sky Flux Plates may be used to study faint extended sources is approximately 0.05 MJy sr(-1). The photometric issues discussed herein are relevant to all IRAS image products, including Sky Flux Plates, co-added images, and the IRAS Sky Survey Atlas (ISSA). We compare the accuracy of data reduction on different products and discuss their relative advantages and disadvantages. We are particularly concerned with the accurate removal of zodiacal backgrounds near the ecliptic plane, a region known as the ISSA Reject Set. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. USN, Res Lab, Washington, DC 20375 USA. RP NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 66 TC 9 Z9 9 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-6256 EI 1538-3881 J9 ASTRON J JI Astron. J. PD FEB PY 1998 VL 115 IS 2 BP 745 EP 766 DI 10.1086/300199 PG 22 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA YW535 UT WOS:000071946100030 ER PT J AU Mason, BD Gies, DR Hartkopf, WI Bagnuolo, WG ten Brummelaar, T McAlister, HA AF Mason, BD Gies, DR Hartkopf, WI Bagnuolo, WG ten Brummelaar, T McAlister, HA TI ICCD speckle observations of binary stars. XIX. An astrometric/spectroscopic survey of O stars SO ASTRONOMICAL JOURNAL LA English DT Review DE binaries, general; binaries, spectroscopic; binaries, visual; open clusters and associations, general ID ULTRAVIOLET RADIAL-VELOCITIES; MASS-RATIO DISTRIBUTION; SPECTROSCOPIC BINARY; RUNAWAY STARS; B-STARS; TOMOGRAPHIC SEPARATION; COMPOSITE SPECTRA; PULSAR COMPANIONS; PLASKETTS STAR; VARIABLE-STARS AB We present the results of a speckle interferometric survey made with the CHARA speckle camera and 4 m-class telescopes of Galactic O-type stars with V < 8. We can detect with the speckle camera binaries in the angular separation range 0".035 < rho < 1".5 with Delta m < 3, and we have discovered 15 binaries among 227 O-type systems. We combined our results on visual binaries with measurements of wider pairs from the Washington Double Star Catalog and fainter pairs from the Hipparcos Catalogue, and we made a literature survey of the spectroscopic binaries among the sample. We then investigated the overall binary frequency of the sample and the orbital characteristics of the known binaries. Binaries are common among O stars in clusters and associations (>59% have a visual or spectroscopic companion) but less so among field and especially runaway stars. There are many triple systems among the speckle binaries, and we discuss their possible role in the ejection of stars from clusters. The period distribution of the binaries is bimodal in log P, but we suggest that binaries with periods of years and decades may eventually be found to fill the gap. The mass ratio distribution of the visual binaries increases toward lower mass ratios, but low mass ratio companions are rare among close, spectroscopic binaries (probably because of the difficulty of spectroscopic detection rather than a real deficit). We present distributions of the eccentricity and longitude of periastron for spectroscopic binaries with elliptical orbits, and we find strong evidence of a bias in the longitude of periastron distribution (the "Barr effect"), which is probably caused by line distortions introduced by circumstellar gas. C1 Georgia State Univ, Ctr High Angular Resolut Astron, Atlanta, GA 30303 USA. RP Mason, BD (reprint author), USN Observ, Astrometry Dept, 3450 Massachusetts Ave, Washington, DC 20392 USA. EM bdm@crux.usno.navy.mil; gies@chara.gsu.edu; hartkopf@chara.gsu.edu; bagnuolo@chara.gsu.edu; theo@chara.gsu.edu; hal@chara.gsu.edu NR 209 TC 300 Z9 301 U1 0 U2 5 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-6256 J9 ASTRON J JI Astron. J. PD FEB PY 1998 VL 115 IS 2 BP 821 EP 847 DI 10.1086/300234 PG 27 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA YW535 UT WOS:000071946100036 ER PT J AU Gaume, RA Wilson, TL Vrba, FJ Johnston, KJ Schmid-Burgk, J AF Gaume, RA Wilson, TL Vrba, FJ Johnston, KJ Schmid-Burgk, J TI Water masers in Orion SO ASTROPHYSICAL JOURNAL LA English DT Article DE masers; radio lines, ISM; stars, individual (Orion BN/KL) ID MOLECULAR CLOUD-1; DUST EMISSION; OMC-1; OUTFLOW; NEBULA; KL; RESOLUTION; CONDENSATIONS; REGION; RIDGE AB Measurements of the 6(16) --> 5(23) line of H2O at 1.3 cm in the Orion region of star formation are reported. With a spatial resolution of approximate to 0." 1, H2O maser emission was detected in two regions: Orion BN/KL and Orion S. The well-known masers in the BN/KL region are distributed in a 30 " by 30 " area. The "shell" masers, within the BN/KL region, are distributed in a 2 " by 0." 5 strip centered on radio source I and are offset from IRc2. The average shell maser spectrum is doubly peaked, resembling the spectrum of the upsilon = 1 SiO masers. The shell masers have deconvolved sizes of 24-38 AU, slightly smaller than the synthesized beam. Newly detected H2O masers in the Orion S region are distributed in a 15 " by 20 " area. One cluster of masers in the Orion S region is found in a thin 0."(6 strip. The velocity range of the masers in this cluster is nearly 65 km s(-1). We suggest that this cluster of masers is associated with the energetic source of the Orion S molecular outflow. A search in the Orion S region for associated maser emission in the ground-state OH main lines and the 9(2) --> 10, A(+) and 6(2) --> 6(1) E lines of CH3OH gave only upper limits, as did a search for centimeter-wavelength continuum. Near-infrared images of the Orion region are presented in the J, H, and K bands. Three objects with very red near-infrared colors were detected in the Orion S region, near the H2O masers and the previously detected millimeter-wavelength dust continuum peak. One of these objects exhibits near-infrared colors consistent with a B2 zero-age main-sequence star. Although this object may heat the northern part of the Orion S dust cloud, its luminosity and separation from the dust maximum make it unlikely that it alone heats the entire Orion S region. More likely, the primary heat source of the Orion S region is deeply embedded in dust and completely extincted in the near-infrared. C1 USN Observ, Washington, DC 20392 USA. Max Planck Inst Radioastron, D-53010 Bonn, Germany. USN Observ, Flagstaff Stn, Flagstaff, AZ 86002 USA. RP Gaume, RA (reprint author), USN Observ, 3450 Massachusetts Ave NW, Washington, DC 20392 USA. NR 33 TC 67 Z9 67 U1 0 U2 2 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 1 PY 1998 VL 493 IS 2 BP 940 EP + DI 10.1086/305161 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA YW232 UT WOS:000071911700041 ER PT J AU McNamara, MF Bottoms, SF AF McNamara, MF Bottoms, SF TI The incidence of respiratory distress syndrome does not increase when preterm delivery occurs greater than 7 days after steroid administration SO AUSTRALIAN & NEW ZEALAND JOURNAL OF OBSTETRICS & GYNAECOLOGY LA English DT Article ID BETAMETHASONE; INFANTS; PREVENTION; MATURATION; TRIAL AB We sought to determine if the risk of the respiratory distress syndrome (RDS) is increased when preterm delivery occurs greater than 7 days from the last steroid administration. At our hospital, steroids were repeated weekly only on inpatients. Linking pharmacy and delivery records, we analyzed the risk of RDS with preterm delivery by interval since last steroid administration. Discriminant function analysis revealed that adjusted for gestational age, there was a negative correlation between interval since last steroids administration and risk for RDS (p<0.05, n=254). Using analysis of variance to control more precisely for gestational age (28-32 weeks, n=19) we found no difference in the risk for RDS with longer intervals since the last steroid administration. We then used multiway contingency analysis to consider intervals as zero to 7 versus greater than 7 days and similar results were obtained. Our findings suggest that the process of pulmonary maturation induced by steroid administration is permanent rather than transient. Repetitive steroid administration does not appear to be beneficial. Only a large, prospective randomized trial could definitively address the issue of repeat steroid administration. However, on the basis of our findings and review of available literature, we believe there is insufficient data to recommend weekly repeat steroid administration to women at risk for preterm delivery. C1 Wayne State Univ, Hutzel Hosp, Dept Obstet & Gynecol, Detroit, MI USA. RP McNamara, MF (reprint author), USN, Med Ctr, Dept Ob Gyn, San Diego, CA 92134 USA. NR 11 TC 12 Z9 13 U1 0 U2 0 PU AUSTRALIAN NZ J OBSTET GYNAEC PI EAST MELBOURNE PA 254 ALBERT STREET COLLEGE HOUSE, EAST MELBOURNE, VIC 3002, AUSTRALIA SN 0004-8666 J9 AUST NZ J OBSTET GYN JI Aust. N. Z. J. Obstet. Gynaecol. PD FEB PY 1998 VL 38 IS 1 BP 8 EP 10 DI 10.1111/j.1479-828X.1998.tb02948.x PG 3 WC Obstetrics & Gynecology SC Obstetrics & Gynecology GA YY776 UT WOS:000072184000002 PM 9521381 ER PT J AU Dufrene, YF Barger, WR Lee, GU AF Dufrene, YF Barger, WR Lee, GU TI Direct characterization of mixed phospholipid/glycolipid bilayers with chemically-functionalized AFM probes SO BIOPHYSICAL JOURNAL LA English DT Meeting Abstract C1 USN, Res Lab, Div Chem, Washington, DC 20375 USA. RI Lee, Gil/P-8696-2016 OI Lee, Gil/0000-0002-7949-5848 NR 0 TC 2 Z9 2 U1 0 U2 1 PU BIOPHYSICAL SOCIETY PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0006-3495 J9 BIOPHYS J JI Biophys. J. PD FEB PY 1998 VL 74 IS 2 BP A330 EP A330 PN 2 PG 1 WC Biophysics SC Biophysics GA ZL549 UT WOS:000073445401911 ER PT J AU Lee, GU MacKerell, AD AF Lee, GU MacKerell, AD TI Structure, force and energy of double-stranded DNA oligonucleotides under tensile load SO BIOPHYSICAL JOURNAL LA English DT Meeting Abstract C1 USN, Res Lab, Div Chem, Washington, DC 20375 USA. Univ Maryland, Sch Pharm, Baltimore, MD 21201 USA. RI Lee, Gil/P-8696-2016 OI Lee, Gil/0000-0002-7949-5848 NR 0 TC 0 Z9 0 U1 0 U2 0 PU BIOPHYSICAL SOCIETY PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0006-3495 J9 BIOPHYS J JI Biophys. J. PD FEB PY 1998 VL 74 IS 2 BP A226 EP A226 PN 2 PG 1 WC Biophysics SC Biophysics GA ZL549 UT WOS:000073445401308 ER PT J AU Randall, D Curry, J Battisti, D Flato, G Grumbine, R Hakkinen, S Martinson, D Preller, R Walsh, J Weatherly, J AF Randall, D Curry, J Battisti, D Flato, G Grumbine, R Hakkinen, S Martinson, D Preller, R Walsh, J Weatherly, J TI Status of and outlook for large-scale modeling of atmosphere-ice-ocean interactions in the Arctic SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID SHALLOW-WATER EQUATIONS; GLOBAL CLIMATE MODEL; GRAVITY-WAVE DRAG; SEA-ICE; THICKNESS DISTRIBUTION; GENERAL-CIRCULATION; NUMERICAL-INTEGRATION; STRATUS CLOUDS; SENSITIVITY; RADIATION AB Arctic air masses have direct impacts on the weather and climatic extremes of midlatitude areas such as central North America. Arctic physical processes pose special and very important problems for global atmospheric models used for climate simulation and numerical weather prediction. At present, the observational database is inadequate to support research aimed at overcoming these problems. Three interdependent Arctic field programs now being planned will help to remedy this situation: SHEBA, which will operate an ice camp in the Arctic for a year; ARM, which will supply instruments for use at the SHEBA ice camp and which will also conduct longer-term measurements near Barrow, Alaska; and FIRE, which will conduct one or more aircraft campaigns, in conjunction with remote-sensing investigations focused on the SHEBA ice camp. This paper provides an introductory overview of the physics of the Arctic from the perspective of large-scale modelers, outlines some of the modeling problems that arise in attempting to simulate these processes, and explains how the data to be provided by the three field programs can be used to test and improve large-scale models. C1 Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 USA. Univ Colorado, Boulder, CO 80309 USA. Univ Washington, Seattle, WA 98195 USA. Canadian Ctr Climate Modelling & Anal, Victoria, BC, Canada. Natl Ctr Environm Predict, Camp Springs, MD USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Lamont Doherty Geophys Observ, Palisades, NY USA. USN, Res Lab, Stennis Space Ctr, MS 39529 USA. Univ Illinois, Urbana, IL 61801 USA. Natl Ctr Atmospher Res, Boulder, CO 80307 USA. RP Randall, D (reprint author), Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 USA. RI Grumbine, Robert/B-9865-2008; Hakkinen, Sirpa/E-1461-2012; Battisti, David /A-3340-2013; Flato, Gregory/K-6711-2015; Randall, David/E-6113-2011 OI Battisti, David /0000-0003-4871-1293; Randall, David/0000-0001-6935-4112 NR 111 TC 110 Z9 115 U1 0 U2 10 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD FEB PY 1998 VL 79 IS 2 BP 197 EP 219 DI 10.1175/1520-0477(1998)079<0197:SOAOFL>2.0.CO;2 PG 23 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA YZ883 UT WOS:000072303900001 ER PT J AU Clarkson, ED Lesser, D Paul, BD AF Clarkson, ED Lesser, D Paul, BD TI Effective GC-MS procedure for detecting iso-LSD in urine after base-catalyzed conversion to LSD SO CLINICAL CHEMISTRY LA English DT Article ID LYSERGIC-ACID DIETHYLAMIDE AB A sensitive method is described to detect isolysergic acid diethylamide (iso-LSD) in urine. The compound was extracted from urine and converted to a C-8 carbanion by sodium ethoxide in ethanol. Protonation of the carbanion by water selectively produced LSD. The conversion of iso-LSD to LSD was almost quantitative (98%). The product was purified by solid-phase fractionation and acid-base separation techniques. The trimethylsilyl derivative of LSD was detected by a gas chromatography-mass spectrometry method. The overall recovery of the procedure was approximately 69%. Quantification of iso-LSD was linear over the concentration range 50-2000 ng/L. In specimen analysis, iso-LSD was detected when the LSD concentration was below the limit of the detection (50 ng/L) of the procedure. Because iso-LSD is a byproduct of illicit preparation of LSD, presence of iso-LSD in urine is an indication of LSD use. C1 USN, Drug Screening Lab, San Diego, CA 92134 USA. RP Paul, BD (reprint author), Off Armed Forces Med Examiner, Div Forens Toxicol, AFIP Annex,1413 Res Blvd, Rockville, MD 20850 USA. NR 18 TC 10 Z9 10 U1 0 U2 2 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 287 EP 292 PG 6 WC Medical Laboratory Technology SC Medical Laboratory Technology GA YW156 UT WOS:000071904100016 PM 9474026 ER PT J AU Kieffer, LV Takimoto, CH Morrison, GB Cantilena, LR Allegra, CJ Grem, JL Marino, M AF Kieffer, LV Takimoto, CH Morrison, GB Cantilena, LR Allegra, CJ Grem, JL Marino, M TI Development of a pharmacokinetic and pharmacodynamic population model of paclitaxel administered with 5-fluorouracil. SO CLINICAL PHARMACOLOGY & THERAPEUTICS LA English DT Meeting Abstract C1 NCI, USN, Metab Oncol Branch, NIH, Bethesda, MD USA. US FDA, Rockville, MD 20857 USA. WRAIR, Washington, DC USA. USUHS, Bethesda, MD 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 0009-9236 J9 CLIN PHARMACOL THER JI Clin. Pharmacol. Ther. PD FEB PY 1998 VL 63 IS 2 MA PIII69 BP 224 EP 224 PG 1 WC Pharmacology & Pharmacy SC Pharmacology & Pharmacy GA ZA963 UT WOS:000072420300348 ER PT J AU Abraham, FF Broughton, JQ AF Abraham, FF Broughton, JQ TI Large-scale simulations of brittle and ductile failure in fcc crystals SO COMPUTATIONAL MATERIALS SCIENCE LA English DT Article; Proceedings Paper CT Symposium on Computational Modeling of Issues in Materials Science at the International Conference on Applied Materials / European-Materials-Research-Society Meeting CY JUN 16-20, 1997 CL STRASBOURG, FRANCE SP European Mat Res Soc ID FRACTURE; DYNAMICS AB We are simulating the failure of three-dimensional notched fee solids under mode one tension using molecular dynamics, simple interatomic potentials and system of tens of millions of atoms. We have discovered that crystal orientation with respect to the uniaxial loading is important; the solid fails by brittle cleavage for a notch with (1 1 0) faces and by ductile plasticity for a notch with (1 1 1) faces or(1 0 0) faces. We argue that the competition between bond-breaking and interplanar slippage is governed by the nonlinearity and anisotropy of the crystal elasticity near materials failure. if the speed of the (1 1 0) brittle crack velocity reaches approximately one-third of the Rayleigh sound speed, a "brittle-to-ductile" transition occurs and is consistent with the onset of a dynamic instability of brittle fracture. Such an instability was seen in our earlier two-dimensional fracture simulations of rare-gas films and appears to be a general feature of the dynamic brittle fracture process. We close with a simulation showing the consequences of a brittle crack colliding with a void. Copyright (C) 1998 Elsevier Science B.V. C1 IBM Corp, Almaden Res Ctr, Div Res, San Jose, CA 95120 USA. USN, Res Lab, Washington, DC 20375 USA. RP Abraham, FF (reprint author), IBM Corp, Almaden Res Ctr, Div Res, San Jose, CA 95120 USA. NR 16 TC 29 Z9 29 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-0256 J9 COMP MATER SCI JI Comput. Mater. Sci. PD FEB PY 1998 VL 10 IS 1-4 BP 1 EP 9 DI 10.1016/S0927-0256(97)00092-X PG 9 WC Materials Science, Multidisciplinary SC Materials Science GA ZD225 UT WOS:000072663900002 ER PT J AU Guth, PL AF Guth, PL TI Comment on "The influence of timescales in basin modeling calculations", by R. O. Thomsen and I. Lerche, Computers & Geosciences, 23, 33-44 SO COMPUTERS & GEOSCIENCES LA English DT Letter ID CAMBRIAN TIME C1 USN Acad, Dept Oceanog, Annapolis, MD 21402 USA. RP Guth, PL (reprint author), USN Acad, Dept Oceanog, Annapolis, MD 21402 USA. NR 11 TC 1 Z9 1 U1 1 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0098-3004 J9 COMPUT GEOSCI JI Comput. Geosci. PD FEB PY 1998 VL 24 IS 1 BP 101 EP 103 PG 3 WC Computer Science, Interdisciplinary Applications; Geosciences, Multidisciplinary SC Computer Science; Geology GA ZM693 UT WOS:000073566400011 ER PT J AU Vollmer, DP Garber, JD Glass, GA Braun, RD St John, TJ Sheu, WJ AF Vollmer, DP Garber, JD Glass, GA Braun, RD St John, TJ Sheu, WJ TI Electrochemical passivity of titanium implanted with 1 MeV gold ions SO CORROSION SCIENCE LA English DT Article DE ion implantation; electrochemical passivity; corrosion AB Titanium samples implanted with 1 MeV gold ions at doses of 8.8 x 10(14) ions/cm(2) to 1.5 x 10(16) ions/cm(2) were allowed to corrode freely in 20 wt% sulfuric acid solution at 40 degrees C while continuously measuring the open circuit potential (OCP). Inductively Coupled Plasma (ICP), was used to calculate the corrosion rates from the corrosive solutions. The time required for the OCP to drop to a value characteristic of pure titanium in this solution (-718 mV(SCE)), was related to the implant dose. Implantation of gold produced a passivating effect but the observed trend towards passivity persisted beyond the depth of implanted gold. Rutherford Backscattering (RBS) and Nuclear Resonance Scattering (NRS) spectra revealed the presence of oxygen atoms recoil-implanted slightly deeper than the gold. Scanning Tunneling Microscopy (STM) was used to study the differences in surface roughness before and after ion implantation. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 OSCA Inc, Lafayette, LA USA. Univ SW Louisiana, Dept Chem Engn, Corros Res Ctr, Lafayette, LA 70504 USA. Univ SW Louisiana, Dept Phys, Acadiana Res Lab, Lafayette, LA 70504 USA. Univ SW Louisiana, Dept Chem, Acadiana Res Lab, Lafayette, LA 70504 USA. USN, Washington, DC USA. RP Vollmer, DP (reprint author), OSCA Inc, Lafayette, LA USA. NR 10 TC 6 Z9 8 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0010-938X J9 CORROS SCI JI Corrosion Sci. PD FEB-MAR PY 1998 VL 40 IS 2-3 BP 297 EP 306 DI 10.1016/S0010-938X(97)00136-4 PG 10 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA ZU271 UT WOS:000074180000012 ER PT J AU Dinsmore, AD Crocker, JC Yodh, AG AF Dinsmore, AD Crocker, JC Yodh, AG TI Self-assembly of colloidal crystals SO CURRENT OPINION IN COLLOID & INTERFACE SCIENCE LA English DT Review ID HARD-SPHERE EQUATION; LOW IONIC-STRENGTH; PHOTONIC BAND-GAP; ELECTROPHORETIC DEPOSITION; CONFINED COLLOIDS; PHASE-SEPARATION; STATE; SUSPENSIONS; PARTICLES AB Recently, there has been much progress in the self-assembly of colloidal crystals. Major advances include the growth of colloidal crystals on lithographically templated substrates, the synthesis of ordered macroporous materials starting with crystalline emulsions, the investigation of the role of entropy in hard sphere colloids in space and on earth, and the use of electrohydrodynamic forces to create ordered structures. C1 USN, Res Lab, Ctr Biomol Sci & Engn, Washington, DC 20375 USA. Univ Penn, Dept Phys & Astron, Philadelphia, PA 19104 USA. RP Dinsmore, AD (reprint author), USN, Res Lab, Ctr Biomol Sci & Engn, 4555 Overlook Ave SW, Washington, DC 20375 USA. RI Crocker, John/D-4991-2012 OI Crocker, John/0000-0001-6239-6010 NR 82 TC 99 Z9 99 U1 9 U2 64 PU ELSEVIER SCIENCE LONDON PI LONDON PA 84 THEOBALDS RD, LONDON WC1X 8RR, ENGLAND SN 1359-0294 J9 CURR OPIN COLLOID IN JI Curr. Opin. Colloid Interface Sci. PD FEB PY 1998 VL 3 IS 1 BP 5 EP 11 PG 7 WC Chemistry, Physical SC Chemistry GA ZB253 UT WOS:000072452500002 ER PT J AU Cholewa, M Kamiya, T Saint, A Prawer, S Legge, G Butler, JE Vestyck, DJ AF Cholewa, M Kamiya, T Saint, A Prawer, S Legge, G Butler, JE Vestyck, DJ TI Diamond membranes: applications for single ion detection using secondary electron emission 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 polycrystalline CVD diamond; single ion detection; vacuum window AB The assessment of mechanisms for radiation damage in both biological and semiconductor systems is much enhanced by ensuring that each cell or memory unit is hit by one and only one ion. Such "single ion" systems operate by detecting the passage of an ion and using the signal to deflect the beam upstream thus ensuring that only a single ion is injected to the system at a time. For biological investigations of the effects of single ion impact on living cells, the ion needs to be extracted from the vacuum of the accelerator through a thin window into the atmosphere. The requirements on such a window are: (a) that it be thin enough to allow the passage of the ion through it without excessive energy loss; (b) that it possess mechanical strength sufficient to survive the pressure differential; and (c) that upon passage of the ion through it, a sufficiently large signal is generated to ensure a 100% efficient detection of the passage of the ion. This set of demanding requirements can be met by a thin diamond window fabricated by CVD technique, taking advantage of the high secondary electron yield of B-doped diamond. In the present work, we report on the use of B-doped diamond membranes for this purpose. (C) 1998 Elsevier Science S.A. C1 Univ Melbourne, Sch Phys, Parkville, Vic 3052, Australia. USN, Res Lab, Washington, DC 20375 USA. Geocenters Inc, Washington, MD 20744 USA. RP Prawer, S (reprint author), Univ Melbourne, Sch Phys, Parkville, Vic 3052, Australia. RI Butler, James/B-7965-2008; Cholewa, Marian/C-9474-2011; OI Butler, James/0000-0002-4794-7176; PRAWER, STEVEN/0000-0002-4959-0828 NR 4 TC 10 Z9 10 U1 0 U2 5 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-9635 J9 DIAM RELAT MATER JI Diam. Relat. Mat. PD FEB PY 1998 VL 7 IS 2-5 BP 510 EP 512 DI 10.1016/S0925-9635(97)00249-5 PG 3 WC Materials Science, Multidisciplinary SC Materials Science GA ZB444 UT WOS:000072472600078 ER PT J AU Chen, LG Sun, FR Wu, CI AF Chen, LG Sun, FR Wu, CI TI Optimal expansion of a heated working fluid with phenomenological heat transfer SO ENERGY CONVERSION AND MANAGEMENT LA English DT Article DE finite-time thermodynamics; heat transfer; phenomenological law ID FINITE-TIME; MAXIMUM-POWER; TRANSFER LAW; OPTIMAL PERFORMANCE; ENGINES; THERMODYNAMICS; EFFICIENCY; CYCLES AB The optimal motion of a piston fitted with a cylinder containing an ideal gas is examined. The gas is heated ata given rate f(t) and coupled to a heat bath with a heat transfer law q proportional to Delta(T-1) for a finite amount of time. The optimal path which maximizes the expansion work is obtained. Several applications of the optimal path are also given. Published by Elsevier Science Ltd. C1 Naval Acad Engn, Fac 306, Wuhan 430033, Peoples R China. RP Wu, CI (reprint author), USN Acad, Dept Mech Engn, Annapolis, MD 21402 USA. NR 50 TC 41 Z9 52 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0196-8904 J9 ENERG CONVERS MANAGE JI Energy Conv. Manag. PD FEB-MAR PY 1998 VL 39 IS 3-4 BP 149 EP 156 DI 10.1016/S0196-8904(96)00231-2 PG 8 WC Thermodynamics; Energy & Fuels; Mechanics SC Thermodynamics; Energy & Fuels; Mechanics GA YL922 UT WOS:000071008400001 ER PT J AU Flack, KA Johnston, JP AF Flack, KA Johnston, JP TI Near-wall flow in a three-dimensional boundary layer on the endwall of a 30 degrees bend SO EXPERIMENTS IN FLUIDS LA English DT Article ID TURBULENT; SWEPT AB Turbulence measurements are reported on the three-dimensional turbulent boundary layer along the centerline of the flat endwall in a 30 degrees bend. Profiles of mean velocities and Reynolds stresses were obtained down to y(+) approximate to 2 for the mean flow and y(+) approximate to 8 for the turbulent stresses. Mean velocity data collapsed well on a simple law-of-the-wall based on the magnitude of the resultant velocity. The turbulence intensity and turbulent shear stress magnitude both increased with increased three-dimensionality. The ratio of these two quantities, the a(1) structure parameter, decreased in the central regions of the boundary layer and showed profile similarity for y(+) < 50. The shear stress vector angle lagged behind the velocity gradient vector angle in the outer region of the boundary layer, however there was an indication that the shear stress vector tends to lead the velocity gradient vector close to the wall. C1 USN Acad, Dept Mech Engn, Annapolis, MD 21402 USA. Stanford Univ, Dept Mech Engn, Stanford, CA 94305 USA. RP Flack, KA (reprint author), USN Acad, Dept Mech Engn, Annapolis, MD 21402 USA. NR 25 TC 4 Z9 4 U1 0 U2 2 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0723-4864 J9 EXP FLUIDS JI Exp. Fluids PD FEB PY 1998 VL 24 IS 2 BP 175 EP 184 DI 10.1007/s003480050164 PG 10 WC Engineering, Mechanical; Mechanics SC Engineering; Mechanics GA ZF621 UT WOS:000072915400009 ER PT J AU Minshull, TA Bruguier, NJ Brozena, JM AF Minshull, TA Bruguier, NJ Brozena, JM TI Ridge-plume interactions or mantle heterogeneity near Ascension Island? SO GEOLOGY LA English DT Article ID MID-ATLANTIC RIDGE; SOUTH-ATLANTIC; CRUSTAL THICKNESS; PB ISOTOPE; OCEAN; ANOMALIES; GEOCHEMISTRY; BATHYMETRY; INVERSION; BASALTS AB Between the Ascension and Bode Verde Fracture Zones, an similar to 200 km length of the axis of the Mid-Atlantic Ridge has a large positive residual depth anomaly and an axial high morphology that suggest a plume influence, New wide-angle seismic and gravity data from this area show that (1) the crustal thickness increases from 6 km at the propagating rift marking the northern limit of the anomalous zone to 10 km at the center of the zone and (2) the residual depth anomalies may be largely explained by Airy isostatic support for these crustal-thickness variations. These observations, combined with the lack of long-wavelength gravity and residual depth anomalies associated with the proposed Ascension plume, suggest either the presence of a weak and intermittent plume, or melting of a series of small mantle heterogeneities. C1 Univ Cambridge, Dept Earth Sci, Bullard Labs, Cambridge CB3 0EZ, England. USN, Res Lab, Code 5110, Washington, DC 20375 USA. RP Univ Cambridge, Dept Earth Sci, Bullard Labs, Madingley Rd, Cambridge CB3 0EZ, England. RI Minshull, Timothy/D-1147-2010 OI Minshull, Timothy/0000-0002-8202-1379 NR 28 TC 22 Z9 22 U1 0 U2 2 PU GEOLOGICAL SOC AMER, INC PI BOULDER PA PO BOX 9140, BOULDER, CO 80301-9140 USA SN 0091-7613 EI 1943-2682 J9 GEOLOGY JI Geology PD FEB PY 1998 VL 26 IS 2 BP 115 EP 118 DI 10.1130/0091-7613(1998)026<0115:RPIOMH>2.3.CO;2 PG 4 WC Geology SC Geology GA YW331 UT WOS:000071924000005 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 Mattox, GA AF Mattox, GA TI France-Germany 1983-93: The struggle to cooperate. SO GERMAN STUDIES REVIEW LA English DT Book Review C1 US Naval Acad, Annapolis, MD 21402 USA. RP Mattox, GA (reprint author), US Naval Acad, Annapolis, MD 21402 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU ARIZ STATE UNIV PI TEMPE PA WEST ASSN GERMAN STUD, TEMPE, AZ 85287-4205 USA SN 0149-7952 J9 GER STUD REV JI Ger. Stud. Rev. PD FEB PY 1998 VL 21 IS 1 BP 192 EP 193 DI 10.2307/1432455 PG 2 WC Area Studies; Humanities, Multidisciplinary SC Area Studies; Arts & Humanities - Other Topics GA ZN518 UT WOS:000073653900073 ER PT J AU Xie, GG Lam, SS AF Xie, GG Lam, SS TI Real-time block transfer under a link-sharing hierarchy SO IEEE-ACM TRANSACTIONS ON NETWORKING LA English DT Article DE admission control; ATM block transfer; burst scheduling; delay guarantee; hierarchical link sharing ID BANDWIDTH ALLOCATION; RESOURCE-MANAGEMENT; NETWORKS; ATM AB Most application data units are too large to be carried in a single packet (or cell) and must be segmented for network delivery. To an application, the end-to-end delays and loss rate of its data units are much more relevant performance measures than ones specified for individual packets (or cells), The concept of a burst (or block) was introduced to represent a sequence of packets (or cells) Bleat carry an application data unit, hn this paper, me describe how a real-time variable bit-rate (VBR) service, with quality of service (QoS) parameters for black transfer delay and block loss rate, can be provided by integrating concepts and delay guarantee results from our previous work on burst scheduling, together with ideas from asynchronous transfer mode (ATM) block transfer, Two new contributions are presented herein. First, we design an admission control algorithm to provide the following two classes of service: bounded-delay block transfer with mo loss, and bounded-delay block transfer at a specified black lass rate, Secondly, me shaw how to extend existing end-to-end delay bounds to networks with hierarchical link sharing. C1 USN, Postgrad Sch, Dept Comp Sci, Monterey, CA 93943 USA. Univ Texas, Dept Comp Sci, Austin, TX 78712 USA. RP Xie, GG (reprint author), USN, Postgrad Sch, Dept Comp Sci, Monterey, CA 93943 USA. EM xie@cs.nps.navy.mil NR 32 TC 3 Z9 4 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 1063-6692 EI 1558-2566 J9 IEEE ACM T NETWORK JI IEEE-ACM Trans. Netw. PD FEB PY 1998 VL 6 IS 1 BP 30 EP 41 DI 10.1109/90.663938 PG 12 WC Computer Science, Hardware & Architecture; Computer Science, Theory & Methods; Engineering, Electrical & Electronic; Telecommunications SC Computer Science; Engineering; Telecommunications GA YX951 UT WOS:000072097000003 ER PT J AU Ziegler, JF Nelson, ME Shell, JD Peterson, RJ Gelderloos, CJ Muhlfeld, HP Montrose, CJ AF Ziegler, JF Nelson, ME Shell, JD Peterson, RJ Gelderloos, CJ Muhlfeld, HP Montrose, CJ TI Cosmic ray soft error rates of 16-Mb DRAM memory chips SO IEEE JOURNAL OF SOLID-STATE CIRCUITS LA English DT Article DE aircraft computers; error analysis; integrated circuit design; integrated circuit measurements; integrated circuit reliability; memory fault diagnosis; memory testing; particle beams ID DYNAMIC RAMS; ABSORPTION; PROTONS; NUCLEI; CELL AB Manufactured 16-Mb DRAM memory chips use three different cell technologies for bit storage: stacked capacitors, trenches with internal charge, and trenches with external charge, We have measured the soft fail probability of 26 different 16-Mb chips produced by nine vendors to evaluate whether the different cell technologies have an impact on the chip soft error rate. This testing involved irradiation with neutrons, protons, and pions, the principle hadrons of terrestrial cosmic rays, The results show clear differences in soft-fail sensitivity, which appears to be related to the cell structure. C1 IBM Corp, Res, Yorktown Heights, NY 10598 USA. USN Acad, Annapolis, MD 21402 USA. Univ Colorado, Nucl Phys Lab, Boulder, CO 80909 USA. IBM Corp, Microelect Div, Hopewell Junction, NY 12533 USA. RP Ziegler, JF (reprint author), IBM Corp, Res, Yorktown Heights, NY 10598 USA. NR 35 TC 29 Z9 29 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 0018-9200 J9 IEEE J SOLID-ST CIRC JI IEEE J. Solid-State Circuit PD FEB PY 1998 VL 33 IS 2 BP 246 EP 252 DI 10.1109/4.658626 PG 7 WC Engineering, Electrical & Electronic SC Engineering GA YU020 UT WOS:000071671800009 ER PT J AU Samaddar, SN Mokole, EL AF Samaddar, SN Mokole, EL TI Biconical antennas with unequal cone angles SO IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION LA English DT Article AB The problem of radiation and reception of electromagnetic waves associated with a spherically capped biconical antenna having unequal cone angles psi(1) and psi(2) is investigated, Both cones that comprise a bicone are excited symmetrically at the apices by a voltage source so that the only higher order modes are TM, A variational expression for the terminal admittance is derived, Under the wide-angle approximation, expressions for the radiated field, the effective height, and the terminal admittance are obtained, In addition, limiting values of these quantities are derived for electrically small and electrically large wide-angle bicones. The results for arbitrary cone angles are new and subsume results that appear in the existing literature as special cases such as where psi(1) = psi(2) or psi(2) = pi/2. Moreover, the approximations of this paper are more accurate than many in the literature, It is argued that the radiation pattern of an electrically small cone is proportional to sin theta, which is similar to that of a short dipole; whereas the pattern behaves like 1/sin theta for electrically large cones, The parameter theta is the angle from the bicone's axis of symmetry to the observation direction, Consequently, the direction of maximum radiation changes with exciting frequency for a bicone of fixed length, Although most of the analyses are presented in the frequency-domain, time-domain responses of bicones are discussed for some special cases that are similar to situations considered by Harrison and Williams. In particular, the time-domain radiated field and the received voltage are shown to depend on the input's passband and on the match between the source and the bicone. C1 USN, Res Lab, Washington, DC 20375 USA. RP Samaddar, SN (reprint author), USN, Res Lab, Washington, DC 20375 USA. NR 13 TC 24 Z9 28 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 0018-926X J9 IEEE T ANTENN PROPAG JI IEEE Trans. Antennas Propag. PD FEB PY 1998 VL 46 IS 2 BP 181 EP 193 DI 10.1109/8.660962 PG 13 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA YV867 UT WOS:000071871300003 ER PT J AU Avramov-Zamurovic, S Oldham, NM Parker, ME Waltrip, BC AF Avramov-Zamurovic, S Oldham, NM Parker, ME Waltrip, BC TI Low-frequency characteristics of thin-film multijunction thermal voltage converters SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article; Proceedings Paper CT IEEE Instrumentation and Measurement Technology Conference - Sensing, Processing, Networking (IMTC/97) CY MAY 18-22, 1997 CL OTTAWA, CANADA SP IEEE Instrumentat & Measurement Soc, IEEE Ottawa Sect DE AC-DC power conversion; error analysis; frequency domain analysis; nonlinear systems; thermal converters; thin-film circuit thermal factors; thin-film circuits; transfer functions AB Low-frequency errors of thin-film multijunction thermal voltage converters are estimated using a simple model based on easily measured parameters. The model predictions are verified by measuring the converter's frequency characteristic using a digitally synthesized source. C1 USN Acad, Weap & Syst Engn Dept, Annapolis, MD 21402 USA. Natl Inst Stand & Technol, Div Elect, Gaithersburg, MD 20899 USA. RP Avramov-Zamurovic, S (reprint author), USN Acad, Weap & Syst Engn Dept, Annapolis, MD 21402 USA. NR 5 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 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD FEB PY 1998 VL 47 IS 1 BP 87 EP 89 DI 10.1109/19.728796 PG 3 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 136CZ UT WOS:000076841900019 ER PT J AU Newman, HS Krowne, CM AF Newman, HS Krowne, CM TI Analysis of ferrite circulators by 2-D finite-element and recursive Green's function techniques SO IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES LA English DT Article DE ferrite circulators; finite-element methods; Green's functions; magnetostatics AB Ferrite circulator operation is analyzed here by two techniques, The first employs a two-dimensional (2-D) finite-element (FE) technique, using a publicly available FE package. We show how to adapt this code to the solution of the magnetostatic equations and solve for the distribution of internal magnetic field inside a round ferrite puck of finite thickness, and use it to verify existing approximations for the demagnetizing fields. Additionally, the 2-D FE method has also been used to calculate the RF fields and scattering parameters in circulators having noncircular shapes, as well as nonuniform material properties and bias conditions, We have also investigated the field solutions for round circulators, calculated using a recursive Green's function (RGF) technique. This technique allows for radially varying properties in the material or bias fields, and thus accommodates the nonuniform demagnetizing field distribution in finite pucks, A comparison of the results of this technique with experiment is made. We show how the impedance-matching structures attached to the circulator affect the field distributions inside, and present plots of the field distributions as a function of frequency, which provide insight into circulator operation. C1 USN, Res Lab, Div Elect Sci & Technol, Microwave Technol Branch, Washington, DC 20375 USA. RP Newman, HS (reprint author), USN, Res Lab, Div Elect Sci & Technol, Microwave Technol Branch, Washington, DC 20375 USA. NR 18 TC 16 Z9 16 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 0018-9480 J9 IEEE T MICROW THEORY JI IEEE Trans. Microw. Theory Tech. PD FEB PY 1998 VL 46 IS 2 BP 167 EP 177 DI 10.1109/22.660983 PG 11 WC Engineering, Electrical & Electronic SC Engineering GA YX405 UT WOS:000072036700005 ER PT J AU Barthelemy, AC Willett, PK AF Barthelemy, AC Willett, PK TI Volumetric array prewhitening SO IEEE TRANSACTIONS ON SIGNAL PROCESSING LA English DT Article DE array signal processing; direction finding; prewhitening ID UNKNOWN COLORED NOISE; SIGNAL; FIELDS; BOUNDS AB Direction finders such as MUSIC experience loss of resolution and increased bias in the presence of nonwhite noise, This paper presents two versions of a steepest descent gradient algorithm that prewhiten the signal received by an arbitrarily oriented volumetric sensor array, minimizing these undesirable effects. The algorithms optimize a whiteness functional over a surface with desirable properties including low dimensionality, unimodality, and concavity, Two ambient noise models facilitate algorithm development through succinct parameterization. The first, which is a novel linear matricial ambient noise model based on a spherical harmonic expansion, places no constraints on array geometry, The second model requires a spatially uniformly sampled sensor array and reduces problem dimensionality associated with exact multidimensional autoregressive modeling, The algorithms estimate a stacked vector arrangement of the model parameters, Application with MUSIC demonstrates enhanced performance in terms of angular resolution and detection of low signal-to-noise ratio (SNR) sources. C1 USN, Undersea Warfare Ctr, Newport, RI 02841 USA. Univ Connecticut, Dept Elect & Syst Engn, Storrs, CT 06268 USA. RP Barthelemy, AC (reprint author), Northrop Grumman Norden Syst Inc, Res Dev & Adv Syst Dept, Norwalk, CT 06856 USA. OI Willett, Peter/0000-0001-8443-5586 NR 34 TC 4 Z9 4 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 1053-587X J9 IEEE T SIGNAL PROCES JI IEEE Trans. Signal Process. PD FEB PY 1998 VL 46 IS 2 BP 281 EP 293 DI 10.1109/78.655415 PG 13 WC Engineering, Electrical & Electronic SC Engineering GA YV869 UT WOS:000071871700001 ER PT J AU Montain, SJ Sawka, MN Latzka, WA Valeri, CR AF Montain, SJ Sawka, MN Latzka, WA Valeri, CR TI Thermal and cardiovascular strain from hypohydration: Influence of exercise intensity SO INTERNATIONAL JOURNAL OF SPORTS MEDICINE LA English DT Article DE dehydration; stroke volume; cardiac output; thermoregulation ID HEAT-STRESS; DEHYDRATION; BLOOD; PERFORMANCE; HYDRATION; TOLERANCE; RESPONSES; PLASMA AB This study determined the effects of exercise intensity on the physiologic (thermal and cardiovascular) strain induced from hypohydration during heat stress. We hypothesized that the added thermal and cardiovascular strain induced by hypohydration would be greater during high intensity than low intensity exercise. Nine heat-acclimated men completed a matrix of nine trials: three exercise intensities, 25%, 45% and 65% (V) over dot O(2)max; and three hydration levels, euhydration and hypohydration at 3% and 5% body weight loss (BWL). During each trial, subjects attempted 50 min of treadmill exercise in a hot room (30 degrees C db, 50% rh) while body temperatures and cardiac output were measured. Hypohydration was achieved by exercise and fluid restriction the day preceding the trials. Core temperature increased (P<0.05) 0.12 degrees C per%BWL at each hypohydration level and was not affected by exercise intensity. Cardiac output was reduced (P<0.05) compared to euhydration levels and was reduced more during high compared to low intensity exercise after 5% BWL. It was concluded that: a) the thermal penalty (core temperature increase) accompanying hypohydration is not altered by exercise intensity; and b) at severe hypohydration levels, the cardiovascular penalty (cardiac output reduction) increases with exercise intensity. C1 USA, Environm Med Res Inst, Thermal & Mt Med Div, Natick, MA 01760 USA. Boston Univ, Med Ctr, USN, Blood Res Lab, Boston, MA USA. RP Montain, SJ (reprint author), USA, Environm Med Res Inst, Thermal & Mt Med Div, Natick, MA 01760 USA. NR 23 TC 28 Z9 29 U1 1 U2 4 PU GEORG THIEME VERLAG PI STUTTGART PA P O BOX 30 11 20, D-70451 STUTTGART, GERMANY SN 0172-4622 J9 INT J SPORTS MED JI Int. J. Sports Med. PD FEB PY 1998 VL 19 IS 2 BP 87 EP 91 DI 10.1055/s-2007-971887 PG 5 WC Sport Sciences SC Sport Sciences GA ZF142 UT WOS:000072867100003 PM 9562215 ER PT J AU Stallworth, PE Kostov, S denBoer, ML Greenbaum, SG Lampe-Onnerud, C AF Stallworth, PE Kostov, S denBoer, ML Greenbaum, SG Lampe-Onnerud, C TI X-ray absorption and magnetic resonance spectroscopic studies of LixV6O13 SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID LITHIUM INTERCALATION; V6O13; XAS; CELLS; V2O5; FTIR AB Polycrystalline LixV6O13 samples, 0.5 less than or equal to x less than or equal to 6, were prepared by chemical intercalation in n-butyl lithium and investigated spectroscopically by x-ray absorption, electron paramagnetic resonance (EPR), and Li-7 solid state nuclear magnetic resonance (NMR). Both the EPR results and the vanadium K-edge x-ray absorption fine structure spectra show that the average oxidation state of the vanadium decreases with the addition of Li, and the x-ray results provide evidence of lithium deficient and oxygen deficient impurity phases. The local symmetry of the vanadium atoms first decreases with increasing x from 0 less than or equal to x less than or equal to 1 and then increases with increasing x as the vanadium octahedral environment becomes less distorted. These changes are revealed by both the intensity of the first V-O peak in the radial distribution function and by the decrease in the x-ray absorption pre-edge peak intensity. However, structural correlations beyond the nearest neighbor atoms rapidly decrease with increasing Li content above x=1.5, reflecting increased disorder. The observed increase in the V-O distance implies a modest lattice expansion with intercalated Li, from 1.93 Angstrom at x=0 (in agreement with x-ray diffraction) to 2.11 Angstrom at x=5. Variable temperature Li-7 NMR linewidth and spin-lattice relaxation measurements demonstrate that dynamic processes govern the spin-lattice relaxation when 0.5 less than or equal to x less than or equal to 2, but paramagnetic and homonuclear dipolar interactions reduce the spin-lattice relaxation time as x is increased beyond 2. The Li-7 NMR lineshape confirms the presence of impurity phases. Paramagnetic and diamagnetic chemical shifts imply local magnetic ordering accompanying the structural changes on lithium intercalation. (C) 1998 American Institute of Physics. [S0021-8979(98)07103-5]. C1 USN Acad, Dept Phys, Annapolis, MD 21402 USA. CUNY Hunter Coll, Dept Phys, New York, NY 10021 USA. MIT, Dept Chem, Cambridge, MA 02139 USA. RP Stallworth, PE (reprint author), USN Acad, Dept Phys, Annapolis, MD 21402 USA. NR 27 TC 25 Z9 25 U1 0 U2 6 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 FEB 1 PY 1998 VL 83 IS 3 BP 1247 EP 1255 DI 10.1063/1.366822 PG 9 WC Physics, Applied SC Physics GA YU523 UT WOS:000071726400014 ER PT J AU Keen, TR Glenn, SM AF Keen, TR Glenn, SM TI Factors influencing model skill for hindcasting shallow water currents during Hurricane Andrew SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID TROPICAL STORM DELIA; BOUNDARY-LAYER MODEL; ENERGY-DISSIPATION; BREAKING WAVES; TURBULENCE; STRESS; FLOW AB Hurricane Andrew made landfall in the Gulf of Mexico after crossing directly over several moored current meter arrays deployed on the Louisiana-Texas shelf. The resulting three-dimensional current, temperature, and salinity time series are used in a quantitative analysis of the factors affecting the hindcast skill of ocean circulation models. This paper describes parameters for quantifying a model's skill at matching both maximum currents and time series at specific locations and depths. It then briefly discusses the following factors with respect to currents hindcast with the Princeton Ocean Model: 1) model domain size; 2) horizontal resolution, including the bathymetry and coastline; 3) vertical resolution (i.e., number of model levels); 4) the surface drag formulation; 5) the bottom drag coefficient; 6) turbulent mixing parameters and sources of turbulence; and 7) the initial temperature field. Model performance is found to be most dependent on parameters within the turbulent energy closure scheme and the initial temperature and salinity distributions. The best overall model performance is gained by adjusting one of the closure scheme coefficients (B-1,) that decreases turbulence dissipation (and increases mixing where a density gradient exists). Results incorporating wave breaking and a depth-dependent initial temperature field, however, are also reasonable, and differences between the model skill parameters are insufficient to determine which approach is preferable. C1 USN, Res Lab, Div Oceanog, Stennis Space Ctr, MS 39529 USA. Rutgers State Univ, Inst Marine & Coastal Sci, New Brunswick, NJ 08903 USA. RP Keen, TR (reprint author), USN, Res Lab, Div Oceanog, Code 7322, Stennis Space Ctr, MS 39529 USA. NR 20 TC 7 Z9 7 U1 1 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD FEB PY 1998 VL 15 IS 1 BP 221 EP 236 DI 10.1175/1520-0426(1998)015<0221:FIMSFH>2.0.CO;2 PN 2 PG 16 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA YV253 UT WOS:000071804700001 ER PT J AU Trump, CL Marmorino, GO AF Trump, CL Marmorino, GO TI Use of single-ping bottom-track ADCP data to characterize small-scale bathymetry SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article AB A shipboard acoustic Doppler current profiler, in its bottom-track mode, estimates the radial velocity of the transducer relative to the bottom and the range from the transducer to the bottom for each beam of each ping. These data, along with attitude data (pitch, roll, and heading), can be used to map the X, Y, and Z positions of the beam/bottom intercepts. This paper shows how these intercepts can then be used to characterize the size, shape, and orientation of small-scale bathymetric features. The method is applied to data collected over a field of sand waves located 40 km east-northeast of Cape Hatteras, North Carolina, in 30 m of water. Forty-five sand waves were crossed. The sand waves were oriented in an east-west direction, had characteristic heights of 3 m, wavelengths of 230 m, and northern slopes steeper than southern slopes (e.g., 3.8% versus 2.4%). Some sand waves were sampled repeatedly and extended for several kilometers. C1 USN, Res Lab, Washington, DC 20375 USA. RP Trump, CL (reprint author), USN, Res Lab, Code 7250, Washington, DC 20375 USA. NR 5 TC 4 Z9 4 U1 1 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD FEB PY 1998 VL 15 IS 1 BP 299 EP 303 DI 10.1175/1520-0426(1998)015<0299:UOSPBT>2.0.CO;2 PN 2 PG 5 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA YV253 UT WOS:000071804700006 ER PT J AU Butcher, RJ Gilardi, RD AF Butcher, RJ Gilardi, RD TI A new class of flexible energetic salts, part 2: The crystal structures of the cubane-1,4-diammonium dinitramide and cubane-1,2,4,7-tetraammonium dinitramide salts SO JOURNAL OF CHEMICAL CRYSTALLOGRAPHY LA English DT Article DE cubane structures; substituted cubanes; cubane ammonium salts; dinitramide salts ID THERMOCHEMISTRY; CHEMISTRY; CUBANES; BASES AB The crystal structures of cubane-1,4-diammonium dinitramide, 1, and cubane-1,2,4,7-tetraammonium dinitramide, 2, have been determined. 1 crystallizes in the space group P2(1)/c with cell dimensions a = 6.018(2), b = 11.642(3), c = 9.754(3) Angstrom, beta = 107.24(2), while 2 crystallizes in the space group P2(1)/c with cell dimensions a = 9.401(4), b = 9.603(3), c = 12.603(4) Angstrom, beta 111.08(3). In these structures the ammonium substituents are symmetrically attached with respect to the cubane skeleton and have neither low lying empty orbitals nor available lone pairs of electrons thus they have a minimal effect on the metrical parameters of the cubane skeleton. All C-C bond lengths are close to the overall average C-C bond length for all reported cubanes of 1.559 Angstrom. The conformations adopted by the dinitramide ions in both structures are quite different, with the bend, twist, and torsion angles for the dinitramide ion in 1 being significantly larger than those found for the dinitramide ions in 2, due to the different types of hydrogen bonding found in the two structures. In 2, the conformation adopted by the adjacent ammonium ions allows two of the three protons from each ammonium cation to form hydrogen bonds in such a manner that they span either the syn or the anti oxygen atoms of a single dinitramide anion. The dinitramide anion is thus constrained by these interactions and is less free to twist and bend. These results provide further confirmation that the metrical parameters of both the cubane and dinitramide moieties are flexible and reflect their local environment. C1 USN, Struct Matter Lab, Res Lab, Washington, DC 20375 USA. Howard Univ, Dept Chem, Washington, DC 20059 USA. RP Gilardi, RD (reprint author), USN, Struct Matter Lab, Res Lab, Washington, DC 20375 USA. RI G, Neela/H-3016-2014 NR 40 TC 13 Z9 15 U1 0 U2 1 PU SPRINGER/PLENUM PUBLISHERS PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1074-1542 J9 J CHEM CRYSTALLOGR JI J. Chem. Crystallogr. PD FEB PY 1998 VL 28 IS 2 BP 95 EP 104 DI 10.1023/A:1022433512219 PG 10 WC Crystallography; Spectroscopy SC Crystallography; Spectroscopy GA ZP675 UT WOS:000073777200001 ER PT J AU Gilardi, RD Butcher, RJ AF Gilardi, RD Butcher, RJ TI A new class of flexible energetic salts, part 4: The crystal structures of hexaaquomagnesium(II), hexaaquomanganese(II), and hexaaquozinc(II) dihydrate salts of dinitramide SO JOURNAL OF CHEMICAL CRYSTALLOGRAPHY LA English DT Article DE hexaaquomagnesium structures; hexaaquomanganese structures; hexaaquozinc structures; dinitramide salts ID THERMOCHEMISTRY AB The crystal structures of the hexaaquomagnesium (1), hexaaquomanganese (2), and hexaaquozinc (3) dihydrate salts of dinitramide have been determined; 1 crystallizes in the monoclinic space group P2(1)/n with cell dimensions a = 9.589(2), b = 7.420(1), c = 11.116(2) Angstrom, beta = 108.25(3)degrees, 2 crystallizes in the monoclinic space group P2(1)/n with cell dimensions a 9.623(4), b = 7.477(2), c = 11.274(3) Angstrom, beta = 108.38(3)degrees and 3 crystallizes in the monoclinic space group P2(1)/n with cell dimensions a = 9.513(1), b = 7.4270(8), c = 11.164(1) Angstrom, beta = 108.806(6)degrees. The three structures are isostructural, consisting of hexaaquo cations, dinitramide anions and water molecules interlinked by an extensive three dimensional hydrogen bonding interactions. All oxygen atoms as well as the central nitrogen atom of the dinitramide anion are involved in acceptor hydrogen bonds with neighboring water protons. As a consequence of the constraints imposed by these hydrogen bonds the dinitramide ions are almost planar with average deviations of 0.01 Angstrom for 1, 0.03 Angstrom for 2 and 0.03 Angstrom for 3. C1 USN, Struct Matter Lab, Res Lab, Washington, DC 20375 USA. Howard Univ, Dept Chem, Washington, DC 20059 USA. RP Gilardi, RD (reprint author), USN, Struct Matter Lab, Res Lab, Washington, DC 20375 USA. RI G, Neela/H-3016-2014 NR 14 TC 13 Z9 14 U1 0 U2 1 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1074-1542 J9 J CHEM CRYSTALLOGR JI J. Chem. Crystallogr. PD FEB PY 1998 VL 28 IS 2 BP 105 EP 110 DI 10.1023/A:1022485529057 PG 6 WC Crystallography; Spectroscopy SC Crystallography; Spectroscopy GA ZP675 UT WOS:000073777200002 ER PT J AU Felix, CL Bewley, WW Aifer, EH Vurgaftman, I Meyer, JR Lin, CH Zhang, D Murry, SJ Yang, RQ Pei, SS AF Felix, CL Bewley, WW Aifer, EH Vurgaftman, I Meyer, JR Lin, CH Zhang, D Murry, SJ Yang, RQ Pei, SS TI Low threshold 3 mu m interband cascade "W" laser SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Article DE interband cascade laser; InAs/GaInSb; mid-infrared; slope efficiency; threshold; type-II semiconductor AB We have demonstrated the operation at lambda approximate to 3.0 mu m of a 22-stage interband cascade laser with a "W" active region for enhanced gain. The threshold current density for a ridge structure is 170 A/cm(2) at 80K, and it remains lower than the best reported intersubband quantum cascade laser results at all T up to the maximum lasing temperature of 225K. At T = 100K, peak output powers up to 532 mW are observed, and the slope of 342 mW/A per facet for high injection levels corresponds to a differential quantum efficiency of 1.6 photons emitted for every injected electron. C1 USN, Res Lab, Washington, DC 20375 USA. Univ Houston, Ctr Space Vacuum Epitaxy, Houston, TX 77204 USA. RP Felix, CL (reprint author), USN, Res Lab, Code 5613, Washington, DC 20375 USA. NR 16 TC 10 Z9 11 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 FEB PY 1998 VL 27 IS 2 BP 77 EP 80 DI 10.1007/s11664-998-0192-2 PG 4 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA YW251 UT WOS:000071913600007 ER PT J AU Guzdar, PN Chaturvedi, PK Papadopoulos, K Ossakow, SL AF Guzdar, PN Chaturvedi, PK Papadopoulos, K Ossakow, SL TI The thermal self-focusing instability near the critical surface in the high-latitude ionosphere SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID HF EXCITED INSTABILITIES; HIGH-POWER; ELECTROMAGNETIC-WAVES; RADIO-WAVES; DENSITY IRREGULARITIES; POLAR IONOSPHERE; PLASMA-WAVES; ARECIBO; SCINTILLATIONS AB A fully nonlinear development of the thermal self-focusing instability of high power radio waves in the ionosphere in the region near the critical surface is the subject of the present study. In the simulation model studied, a high-powered radio wave in the frequency range 5 - 10 MHz, with a 1% amplitude modulation, is launched vertically. In the high latitude geometry this represents a direction antiparallel to the magnetic field which is almost vertically downwards. The modulated wave undergoes strong self-focusing at the critical surface, where the group velocity of the wave goes to zero. The scale size of the structures transverse to the magnetic field is controlled by the wave intensity and the die-action effects. The large parallel thermal conduction leads to the diffusion of these irregularities into the underdense and overdense plasma in narrow filaments. The depletion in the density in the overdense plasma allows propagation of the wave to higher altitude above the original critical surface and hence into the overdense plasma. C1 Univ Maryland, Inst Plasma Phys, College Pk, MD 20742 USA. Univ Maryland, Dept Phys, College Pk, MD 20742 USA. USN, Res Lab, Div Plasma Phys, Washington, DC 20375 USA. RP Guzdar, PN (reprint author), Univ Maryland, Inst Plasma Phys, College Pk, MD 20742 USA. EM guzdar@ipr.umd.edu; kp@astro.umd.edu; os-sakaw@nrl.navy.mil.gov NR 32 TC 39 Z9 40 U1 0 U2 1 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 FEB 1 PY 1998 VL 103 IS A2 BP 2231 EP 2237 DI 10.1029/97JA03247 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA YV622 UT WOS:000071845800033 ER PT J AU Bernhardt, PA Huba, JD Swartz, WE Kelley, MC AF Bernhardt, PA Huba, JD Swartz, WE Kelley, MC TI Incoherent scatter from space shuttle and rocket engine plumes in the ionosphere SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID ION VELOCITY RING; INSTABILITIES DRIVEN; F-REGION; PLASMA; RADAR; DISTRIBUTIONS; CLOUDS AB Enhanced echoes from the 430 MHz radar at Arecibo were observed during burns of the space shuttle orbital maneuver subsystem (OMS) engines near 317 km altitude. Similar radar signatures of enhanced backscatter were also obtained by the Millstone Hill radar observing the plume of a Centaur engine burning in the ionosphere. A theoretical model of incoherent scatter is presented to explain the radar backscatter observations. The theory considers molecular ion beams generated in the exhaust plume as a result of charge exchange between the ambient O+ ions and the high-speed exhaust molecules (primarily H2O). The field-aligned gyromotion of the pickup ions affects the radio wave scattering from the random thermal fluctuations of electron density. Numerical calculations are carried out for plasmas modified by the space shuttle or Centaur engines, and reasonable agreement with observations is found for the total scattered power. Incoherent backscatter spectra respond to characteristics of the exhaust plume such as vector flow velocity, temperature, and composition; The nonequilibrium velocity distributions for the ions in the pickup ion plume are similar to the distributions found in strongly convecting auroral region ionospheres. The incoherent scatter from the plume ions can be used to validate techniques used to study naturally disturbed plasmas. The predictions of our radar scatter calculations will be tested in future experiments using the space shuttle OMS engines over incoherent scatter radars located at equatorial latitudes and midlatitudes. C1 USN, Res Lab, Div Plasma Phys, Washington, DC 20375 USA. Cornell Univ, Sch Elect Engn, Ithaca, NY 14853 USA. RP Bernhardt, PA (reprint author), USN, Res Lab, Div Plasma Phys, 4555 Overlook Ave SW, Washington, DC 20375 USA. NR 33 TC 15 Z9 16 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 FEB 1 PY 1998 VL 103 IS A2 BP 2239 EP 2251 DI 10.1029/97JA02866 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA YV622 UT WOS:000071845800034 ER PT J AU Williams, KJ Nichols, LT Esman, RD AF Williams, KJ Nichols, LT Esman, RD TI Photodetector nonlinearity limitations on a high-dynamic range 3 GHz fiber optic link SO JOURNAL OF LIGHTWAVE TECHNOLOGY LA English DT Article DE analog systems; electrooptic modulation; optical fiber delay lines; nonlinear distortion; nonlinearities; phase matching; photodetectors; photodiodes ID INTERMODULATION DISTORTION; MICROWAVE PHOTODETECTORS; EXTERNAL MODULATION; TRANSMISSION; PERFORMANCE AB The performance of a de to 3 GHz externally modulated link utilizing balanced high-power photodetection is presented, Nonlinearity measurements of high power photodiodes show 1 dB compression currents in excess of 55 mA and an output third-order intercept point of +32 to +34 dBm, These high current photodetectors permit the use of high power lasers as external modulator sources for low noise fiber optic links with only small degradations in the predicted link dynamic range. An externally modulated link with a 240 mW NdYAG laser, a dual-output 4-V V-pi (de) modulator, and balanced 100 mA total photocurrent yielded a link noise figure from 15.5 to 17.5 dB, a spur-free dynamic range of 119.5 dBHz(2/3), and a l-dB compression dynamic range of 168.4 dBHz. C1 USN, Res Lab, Washington, DC 20375 USA. RP Williams, KJ (reprint author), USN, Res Lab, Washington, DC 20375 USA. NR 30 TC 87 Z9 87 U1 0 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0733-8724 J9 J LIGHTWAVE TECHNOL JI J. Lightwave Technol. PD FEB PY 1998 VL 16 IS 2 BP 192 EP 199 DI 10.1109/50.661009 PG 8 WC Engineering, Electrical & Electronic; Optics; Telecommunications SC Engineering; Optics; Telecommunications GA YW032 UT WOS:000071888800003 ER PT J AU Mossadegh, R Sanghera, JS Schaafsma, D Cole, BJ Nguyen, VQ Miklos, PE Aggarwal, ID AF Mossadegh, R Sanghera, JS Schaafsma, D Cole, BJ Nguyen, VQ Miklos, PE Aggarwal, ID TI Fabrication of single-mode chalcogenide optical fiber SO JOURNAL OF LIGHTWAVE TECHNOLOGY LA English DT Article DE chalcogenide fiber; double crucible technique; fiber fabrication; fiber loss measurement; infrared optical fiber; numerical aperture; single-mode fiber; sulphide optical fiber ID GLASS; AMPLIFIERS AB Long lengths (>150 m) of single-mode chalcogenide optical fiber were fabricated by a double crucible technique, Single-mode transmission through 10 m of continuous fiber was demonstrated using an F-center laser at 2.7 mu m. The optical loss of this fiber was measured by a standard cutback technique using an FTIR spectrometer and also using an F-center laser, A minimum loss of less than 1 dB/m was obtained. C1 Univ Greenbeld, Res Fdn, Greenbelt, MD 20770 USA. USN, Res Lab, Washington, DC 20375 USA. Virginia Polytech Inst & State Univ, Blacksburg, VA 24061 USA. SFA Inc, Landover, MD 20785 USA. RP Mossadegh, R (reprint author), Univ Greenbeld, Res Fdn, Greenbelt, MD 20770 USA. NR 11 TC 34 Z9 36 U1 3 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0733-8724 J9 J LIGHTWAVE TECHNOL JI J. Lightwave Technol. PD FEB PY 1998 VL 16 IS 2 BP 214 EP 217 DI 10.1109/50.661012 PG 4 WC Engineering, Electrical & Electronic; Optics; Telecommunications SC Engineering; Optics; Telecommunications GA YW032 UT WOS:000071888800006 ER PT J AU Yang, HS Kirkpatrick, SM Dennis, WM AF Yang, HS Kirkpatrick, SM Dennis, WM TI Nonequilibrium phonon dynamics in LaF3 : Pr3+ SO JOURNAL OF LUMINESCENCE LA English DT Article; Proceedings Paper CT 11th International Conference on Dynamical Processes in Excited States of Solids CY JUL 20-24, 1997 CL MITTELBERG, AUSTRIA SP Deutsch Forschungsgemein, WE Heraeus Fdn DE nonequilibrium phonons; lattice dynamics; LaF3 ID LAF3 AB The presence of low-lying optical modes in LaF3 can introduce additional decay processes which cause the frequency dependence of the phonon relaxation rate to deviate from the omega(5) dependence predicted by the isotropic dispersionless model. In this paper we investigate the frequency dependence of the phonon relaxation rate in LaF3:Pr3+ over a wide range of frequencies using a combination of defect-induced. one-phonon absorption and absorption vibronic sideband spectroscopy. For comparison with our experimental results, we calculate the phonon relaxation rates for a system with low-lying optical modes. In our model, we consider that both the dispersion curves and the three-phonon coupling constants are isotropic. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ Georgia, Dept Phys & Astron, Athens, GA 30602 USA. USN, Res Lab, Laser Phys Branch, Washington, DC 20375 USA. RP Dennis, WM (reprint author), Univ Georgia, Dept Phys & Astron, Athens, GA 30602 USA. NR 9 TC 1 Z9 2 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-2313 J9 J LUMIN JI J. Lumines. PD FEB PY 1998 VL 76-7 BP 540 EP 543 DI 10.1016/S0022-2313(97)00246-9 PG 4 WC Optics SC Optics GA ZF211 UT WOS:000072874800123 ER PT J AU Marquardt, CL Pinto, JF Allen, RE Esterowitz, L Dergachev, AY Ke, S Mirov, SB AF Marquardt, CL Pinto, JF Allen, RE Esterowitz, L Dergachev, AY Ke, S Mirov, SB TI Method for producing large, stable concentrations of Sc2+ in optically clear CaF2 crystals SO JOURNAL OF MATERIALS RESEARCH LA English DT Article AB This communication describes a new method for producing stable, high concentrations of Sc2+ in optically clear CaF2 crystals. We have achieved Sc2+ concentrations as high as 3 x 10(18) cm(-3) without degradation of optical quality. We have converted as much as 5% of the scandium dopant to the divalent state. The concentration of divalent scandium is stable during room temperature storage for periods of at least one year. C1 USN, Res Lab, Washington, DC 20375 USA. Univ Alabama, Birmingham, AL 35294 USA. RP Marquardt, CL (reprint author), USN, Res Lab, Washington, DC 20375 USA. NR 11 TC 2 Z9 2 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD FEB PY 1998 VL 13 IS 2 BP 257 EP 260 DI 10.1557/JMR.1998.0035 PG 4 WC Materials Science, Multidisciplinary SC Materials Science GA ZJ205 UT WOS:000073190000004 ER PT J AU Sunada, F Rash, FC Tam, DA AF Sunada, F Rash, FC Tam, DA TI MRI findings in a patient with partial monosomy 10p SO JOURNAL OF MEDICAL GENETICS LA English DT Article DE partial monosomy 10p; MRI findings ID DELETION SYNDROME; DIGEORGE AB Partial monosomy 10p is a rare chromosomal disorder charaterised by frontal bossing, micrognathia, congenital heart defects, vesicoureteral abnormalities, and developmental delay. This is the first report to describe seizures not associated with hypocalcaemia, as well as cortical atrophy and decreased white matter volume on magnetic resonance imaging, in a patient with documented partial monosomy 10p. The neuroradiographic abnormalities found in this patient provide a first step towards understanding the aetiology of the developmental delay and ventriculomegaly associated with this chromosomal abnormality. C1 USN, Dept Pediat & Clin Invest, Med Ctr, San Diego, CA 92152 USA. Uniformed Serv Univ Hlth Sci, Bethesda, MD 20814 USA. Univ Calif San Diego, Div Child Neurol, San Diego, CA 92103 USA. RP Tam, DA (reprint author), USN, Dept Clin Invest, Med Ctr, 34800 Bob Wilson Dr, San Diego, CA 92134 USA. NR 18 TC 11 Z9 11 U1 0 U2 0 PU BRITISH MED JOURNAL PUBL GROUP PI LONDON PA BRITISH MED ASSOC HOUSE, TAVISTOCK SQUARE, LONDON WC1H 9JR, ENGLAND SN 0022-2593 J9 J MED GENET JI J. Med. Genet. PD FEB PY 1998 VL 35 IS 2 BP 159 EP 161 DI 10.1136/jmg.35.2.159 PG 3 WC Genetics & Heredity SC Genetics & Heredity GA YW967 UT WOS:000071992700016 PM 9507399 ER PT J AU Merzbacher, CI Barker, JG Swider, KE Rolison, DR AF Merzbacher, CI Barker, JG Swider, KE Rolison, DR TI Effect of re-wetting on silica aerogel structure: a SANS study SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Letter ID NEUTRON-SCATTERING AB Small angle neutron scattering (SANS) has been used to study (1) the ability to refill the pores of a silica aerogel (rho = 0.3 g/cm(3)) with water and (2) and effect of the water and the re-wetting process on the aerosol structure on the 1 nm to 100 nm scale. A sample filled with a D2O:H2O solution which was chosen tu match the scattering properties of silica shows no scattering at length scales < 40 nm down to the detection limit (similar to 2 nm) of the experiment. This lack of scattering demonstrates that the mesopores of the silica aerogel were successfully filled with the contrast-matching fluid. SANS spectra for samples filled with air or D2O are similar, indicating that the aerogel structure as detected by this technique is not affected by the reintroduction of water into the pores. Results suggest that some aerogels may be suited for applications in aqueous environments such as catalysis or chemical sensing. (C) 1998 Elsevier Science B.V. C1 USN, Res Lab, Div Opt Sci, Washington, DC 20375 USA. NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. USN, Res Lab, Div Chem, Washington, DC 20375 USA. RP Merzbacher, CI (reprint author), USN, Res Lab, Div Opt Sci, Washington, DC 20375 USA. EM merzbacher@nrl.navy.mil NR 18 TC 13 Z9 13 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD FEB PY 1998 VL 224 IS 1 BP 92 EP 96 DI 10.1016/S0022-3093(97)00454-7 PG 5 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA ZB560 UT WOS:000072484800013 ER PT J AU Dawson, TH AF Dawson, TH TI On Markov theory and wave-crest statistics SO JOURNAL OF OFFSHORE MECHANICS AND ARCTIC ENGINEERING-TRANSACTIONS OF THE ASME LA English DT Article AB The Longuet-Higgins connection between Markov description of runs of high waves and the truncated frequency spectrum of a given sea is developed in a simplified experimentally based manner using combined results from envelope and Markov theories. A high-frequency truncation limit is proposed as 2 omega(p) - 0.5 omega(o), where w(p) denotes peak spectral frequency and w(o) denotes mean frequency. Results are shown to apply to measurements from laboratory and computer simulations of standard Bretschneider and Jonswap seas. C1 USN Acad, Ocean Engn Program, Annapolis, MD 21402 USA. RP Dawson, TH (reprint author), USN Acad, Ocean Engn Program, Annapolis, MD 21402 USA. NR 7 TC 2 Z9 2 U1 1 U2 1 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0892-7219 J9 J OFFSHORE MECH ARCT JI J. Offshore Mech. Arct. Eng. Trans. ASME PD FEB PY 1998 VL 120 IS 1 BP 56 EP 58 DI 10.1115/1.2829521 PG 3 WC Engineering, Ocean; Engineering, Mechanical SC Engineering GA YY610 UT WOS:000072165500008 ER PT J AU Viudez, A Haney, RL Vazquez-Cuervo, J AF Viudez, A Haney, RL Vazquez-Cuervo, J TI The deflection and division of an oceanic baroclinic jet by a coastal boundary: A case study in the Alboran Sea SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID SYNOPTIC HYDROGRAPHIC OBSERVATIONS; STAGNATION-POINT FLOW; ANTICYCLONIC GYRES; ROTATING FLUID; CIRCULATION; SEPARATION; VORTICITY; TURBULENCE; GIBRALTAR; EDDIES AB An oceanic baroclinic jet impinging on a coastal boundary represents a particular type of ocean-coast interaction. This specific oceanographic phenomenon is an example of the stagnation in line flows occurring in fluid dynamics with three additional features: rotation, stratification, and a sloping boundary. In this study the authors describe the density, vorticity, and deformation characteristics of an oceanic jet impinging on a sloping boundary. The case study corresponds to the impinging process of the Atlantic jet at the African coast (Alboran Sea). In the impinging region, the acceleration field is divergent related to the fact that the magnitude of the deformation is larger than the magnitude of the rotation. It is also found that the stagnation streamsurface does not lie in a vertical plane but tilts in the opposite direction to the tilt of the isopycnals. The how upstream of the stagnation point is characterized by backing, speed convergence, diffluence, and negative streamwise vorticity. The flow past the stagnation point is characterized by veering, speed divergence, confluence, and positive streamwise vorticity. The current can only be considered irrotational in a narrow part of the impinging region. C1 Naval Postgrad Sch, Dept Meteorol, Monterey, CA USA. CALTECH, Jet Prop Lab, Pasadena, CA USA. RP Viudez, A (reprint author), Univ Illes Balears, Dept Fis, E-07071 Palma de Mallorca, Spain. EM DFSAVL4@PS.UIB.ES RI Viudez, Alvaro/A-8201-2008 OI Viudez, Alvaro/0000-0001-7862-9835 NR 81 TC 7 Z9 7 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-3670 J9 J PHYS OCEANOGR JI J. Phys. Oceanogr. PD FEB PY 1998 VL 28 IS 2 BP 289 EP 308 DI 10.1175/1520-0485(1998)028<0289:TDADOA>2.0.CO;2 PG 20 WC Oceanography SC Oceanography GA YY524 UT WOS:000072156200008 ER PT J AU Weishaupt, K Held, JT Hochheimer, HD Qadri, SB Skelton, EF Brister, K AF Weishaupt, K Held, JT Hochheimer, HD Qadri, SB Skelton, EF Brister, K TI Equation of state of PrBa2Cu3O7-delta SO JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS LA English DT Article DE superconductors; high pressure; X-ray diffraction; equations-of-state ID HIGH-TEMPERATURE SUPERCONDUCTORS; VANHOVE SCENARIO; UNIAXIAL-STRESS; YBA2CU3O7; TC AB We have measured the pressure-dependence of the lattice-parameters of PrBa2Cu3O7-delta at room temperature up to 3.5 GPa using energy-dispersive X-ray diffraction. These results have been used to calculate the pressure-dependence of the unit-cell volume and to determine the equation of state of this material. Published by Elsevier Science Ltd. C1 Colorado State Univ, Dept Phys, Ft Collins, CO 80523 USA. USN, Res Lab, Div Condensed Matter & Radiat Sci, Washington, DC 20375 USA. Cornell Univ, Cornell High Energy Synchrotron Source, Wilson Lab, Ithaca, NY 14853 USA. RP Weishaupt, K (reprint author), Colorado State Univ, Dept Phys, Ft Collins, CO 80523 USA. NR 15 TC 2 Z9 2 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-3697 J9 J PHYS CHEM SOLIDS JI J. Phys. Chem. Solids PD FEB PY 1998 VL 59 IS 2 BP 211 EP 214 DI 10.1016/S0022-3697(97)00138-8 PG 4 WC Chemistry, Multidisciplinary; Physics, Condensed Matter SC Chemistry; Physics GA YR502 UT WOS:000071501700009 ER PT J AU Yang, Y Photiadis, DM AF Yang, Y Photiadis, DM TI Stochastic model for wave localization in one-dimensional disordered structures SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article ID ANDERSON LOCALIZATION; VIBRATION; IRREGULARITY; CONFINEMENT; ENERGY AB This paper presents a probabilistic study of the effects of structural irregularity on wave propagation along an infinite 1-D chain. A general integral equation method based on Markov chain theory is used to determine the phase probability density function (pdf) at the scatterers distributed irregularly along the chain. The scatterers could be atoms in a one-dimensional crystal, or ribs on a flat plate or membrane. The integral equation derived for the phase pdf is simplified considerably when the scatterers are distributed completely randomly or quasi-periodically. In these cases, the integral equations may be asymptotically solved for the phase density functions in the limit of weak or strong scattering; the localization factors are then obtained. The present approach is quite general and is directly applicable to any disordered one-dimensional system consisting of identical scatterers that are arranged according to a probability distribution function. The validity of the present asymptotic solutions is examined and verified by comparing against the existing analytical solutions for simple atomic or mechanical disordered systems. (C) 1998 Acoustical Society of America. [S0001-4966(98)00402-0]. C1 SFA Inc, Landover, MD 20785 USA. USN, Res Lab, Washington, DC 20375 USA. RP Yang, Y (reprint author), SFA Inc, 1401 McCormick Dr, Landover, MD 20785 USA. NR 14 TC 1 Z9 1 U1 0 U2 1 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 FEB PY 1998 VL 103 IS 2 BP 751 EP 759 DI 10.1121/1.421239 PG 9 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA YX461 UT WOS:000072042300012 ER PT J AU Smith, AR Smith, KB AF Smith, AR Smith, KB TI Mode functions for the wide-angle approximation to the parabolic equation SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article ID PROPAGATION; HELMHOLTZ; OCEAN AB The parabolic approximation to the wave equation is examined within the context of normal mode theory. In a layered waveguide, the horizontal propagation constants and modal amplitudes of the field Psi satisfying the standard parabolic equation (SPE) approximation can be mapped exactly into the amplitudes and wave numbers of the normal modes for the field p satisfying the Helmholtz wave equation. However, this is not the case for certain other parabolic approximations, such as the wide-angle parabolic equation (WARE) approximation. Approximate mode functions for the WAPE approximation are developed. These mode functions are then used to decompose range-independent sound-pressure fields computed using the WAPE approximation. The resulting modal coefficients and eigenfunctions obtained using the WAPE mode functions are compared with those obtained using standard normal mode theory. (C) 1998 Acoustical Society of America. [S0001-4966(98)03901-0]. C1 USN, Postgrad Sch, Dept Phys, Monterey, CA 93943 USA. RP Smith, AR (reprint author), USN, Postgrad Sch, Dept Phys, Monterey, CA 93943 USA. NR 21 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 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD FEB PY 1998 VL 103 IS 2 BP 814 EP 821 DI 10.1121/1.421202 PG 8 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA YX461 UT WOS:000072042300019 ER PT J AU Furman, MI Benoit, SE Barnard, MR Valeri, CR Borbone, ML Becker, RC Hechtman, HB Michelson, AD AF Furman, MI Benoit, SE Barnard, MR Valeri, CR Borbone, ML Becker, RC Hechtman, HB Michelson, AD TI Increased platelet reactivity and circulating monocyte-platelet aggregates in patients with stable coronary artery disease SO JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY LA English DT Article ID GRANULE MEMBRANE-PROTEIN; P-SELECTIN; ACTIVATED PLATELETS; MONOCLONAL-ANTIBODY; UNSTABLE ANGINA; IN-VIVO; MYOCARDIAL-INFARCTION; LEUKOCYTE AGGREGATION; ADENOSINE-DIPHOSPHATE; CYTOMETRIC DETECTION AB Objectives. We sought to examine whether patients with stable coronary artery disease (CAD) have increased platelet reactivity and an enhanced propensity to form monocyte-platelet aggregates. Background. Platelet-dependent thrombosis and leukocyte infiltration into the vessel wall are characteristic cellular events seen in atherosclerosis. Methods. Anticoagulated peripheral venous blood from 19 patients with stable CAD and 19 normal control subjects was incubated with or without various platelet agonists and analyzed by whole blood Bow cytometry, Results. Circulating degranulated platelets were increased in patients with CAD compared with control subjects (mean [+/-SEM] percent P-selectin-positive platelets: 2.1 +/- 0.2 vs, 1.5 +/- 0.2, p < 0.01) and were more reactive to stimulation with 1 mu mol/liter of adenosine diphosphate (ADP) (28.7 +/- 3.9 vs. 16.1 +/- 2.2, p < 0.01), 1 mu mol/liter of ADP/epinephrine (51.4 +/- 4.6 vs, 37.5 +/- 3.8, p < 0.05) or 5 mu mol/liter of thrombin receptor agonist peptide (TRAP) (65.7 +/- 6.8 vs, 20.2 +/- 5.1, p < 0.01), Patients with stable CAD also had increased circulating monocyte-platelet aggregates compared with control subjects (percent platelet positive monocytes: 15.3 +/- 3.0 Vs, 6.3 +/- 0.9, p < 0.01), Furthermore, patients with stable CAD formed more monocyte-platelet aggregates than did control subjects when their whole blood was stimulated with 1 mu mol/liter of ADP (50.4 +/- 4.5 vs. 28.1 +/- 5.3, p < 0.01), 1 mu mol/liter of ADP/epinephrine (60.7 +/- 4.3 vs. 48.0 +/- 4.8, p < 0.05) or 5 mu mol/liter of TRAP (67.6 +/- 5.7 vs, 34.3 +/- 7.0, p < 0.01), Conclusions. Patients with stable CAD have circulating activated platelets, circulating monocyte platelet aggregates, increased platelet reactivity and an increased propensity to form monocyte-platelet aggregates. (C) 1998 by the American College of Cardiology. C1 Univ Massachusetts, Med Ctr, Div Cardiovasc Med,Cardiovasc Thrombosis Res Ctr, Ctr Platelet Funct Studies, Worcester, MA 01655 USA. Univ Massachusetts, Med Ctr, Dept Med, Worcester, MA 01655 USA. Univ Massachusetts, Med Ctr, Dept Pediat, Worcester, MA 01655 USA. Univ Massachusetts, Med Ctr, Dept Surg, Worcester, MA 01655 USA. Boston Univ, Sch Med, USN, Blood Res Lab, Boston, MA 02118 USA. Harvard Univ, Brigham & Womens Hosp, Sch Med, Dept Surg, Boston, MA 02115 USA. RP Furman, MI (reprint author), Univ Massachusetts, Med Ctr, Div Cardiovasc Med,Cardiovasc Thrombosis Res Ctr, Ctr Platelet Funct Studies, 55 Lake Ave N, Worcester, MA 01655 USA. FU NIGMS NIH HHS [GM24891-18, GM35141-10] NR 56 TC 356 Z9 368 U1 0 U2 2 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 BP 352 EP 358 DI 10.1016/S0735-1097(97)00510-X PG 7 WC Cardiac & Cardiovascular Systems SC Cardiovascular System & Cardiology GA YV175 UT WOS:000071796900018 PM 9462579 ER PT J AU Heilman, MEJ AF Heilman, MEJ TI A simplified pattern for a cast metal post SO JOURNAL OF THE AMERICAN DENTAL ASSOCIATION LA English DT Article C1 USN, Jacksonville, FL USA. RP Heilman, MEJ (reprint author), 2348 Glenfinnan Dr, Orange Pk, FL 32073 USA. NR 0 TC 3 Z9 3 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 223 EP 223 PG 1 WC Dentistry, Oral Surgery & Medicine SC Dentistry, Oral Surgery & Medicine GA YW277 UT WOS:000071916200020 PM 9495056 ER PT J AU Le, TP Tuazon, CU AF Le, TP Tuazon, CU TI Human immunodeficiency virus (HIV) infection in older people: A case report SO JOURNAL OF THE AMERICAN GERIATRICS SOCIETY LA English DT Letter ID AIDS; EPIDEMIOLOGY C1 USN, Med Res Inst, Rockville, MD 20852 USA. George Washington Univ, Med Ctr, Washington, DC 20037 USA. RP Le, TP (reprint author), USN, Med Res Inst, Rockville, MD 20852 USA. NR 12 TC 0 Z9 0 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 USA SN 0002-8614 J9 J AM GERIATR SOC JI J. Am. Geriatr. Soc. PD FEB PY 1998 VL 46 IS 2 BP 249 EP 250 PG 2 WC Geriatrics & Gerontology; Gerontology SC Geriatrics & Gerontology GA YW198 UT WOS:000071908300023 PM 9475460 ER PT J AU Wolter, SD Mohney, SE Venugopalan, H Wickenden, AE Koleske, DD AF Wolter, SD Mohney, SE Venugopalan, H Wickenden, AE Koleske, DD TI Kinetic study of the oxidation of gallium nitride in dry air SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID ALUMINUM NITRIDE; GAN AB The oxidation of polycrystalline GaN powder and GaN epi layers in dry air has been investigated. Bulk theta-2 theta X-ray diffraction (XRD) revealed no evidence of oxide formation on the powder specimen exposed to temperatures of to 750 degrees C for 25 h. However, when oxidized at temperatures of 900 degrees C or greater for 1 h or longer, an oxide was observed to form and was identified as the monoclinic beta-Ga2O3, the same oxide observed previously by the present investigators to form on epitaxial GaN films. Information regarding the oxidation kinetics was obtained in the present study by measuring the intensity of the beta-Ga2O3, ((2) over bar 1 7) XRD peak as a function of oxidation time at various temperatures, and the initial stage of the oxidation was found to be limited by the rate of an interfacial reaction with an activation energy of similar to 3 x 10(5) J/mol. An interfacial reaction-controlled mechanism was also observed to limit the rate of oxidation of GaN epi layers at 900 degrees C. C1 Penn State Univ, Dept Mat Sci & Engn, University Pk, PA 16802 USA. USN, Res Lab, Elect Sci & Technol Div, Washington, DC 20375 USA. RP Wolter, SD (reprint author), Penn State Univ, Dept Mat Sci & Engn, University Pk, PA 16802 USA. NR 14 TC 40 Z9 40 U1 4 U2 21 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 10 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD FEB PY 1998 VL 145 IS 2 BP 629 EP 632 DI 10.1149/1.1838314 PG 4 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA YW750 UT WOS:000071969500050 ER PT J AU Statman, D Stefanini, CC Statman, MM Gilbreath, GC AF Statman, D Stefanini, CC Statman, MM Gilbreath, GC TI Temporal memory effects in photorefractive two-beam coupling: a study comparing n-doped and p-doped BaTiO3 at 514 nm and 830 nm SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID STEADY-STATE; CRYSTALS; AMPLIFICATION; BI12SIO20 AB The photorefractive gain and time response of n-doped and p-doped BaTiO3 were compared in the visible, lambda = 514 nm, and in the infrared, lambda = 830 nm. Two-beam coupling experiments were conducted for beam ratios between 3600:1, 5000:1, and 8000:1. In both infrared and visible it was observed that the measured gains were higher for the p-BaTiO3 by an order of magnitude or more. When the gain was high, a temporal memory effect was observed, suggesting that the time dependence of the space-charge field is determined by the history of the modulation depth. This effect is shown to be consistent with the Kukhtarev equations for a single carrier. Low-gain behavior was observed at all interaction angles for both crystals in the IR. In the visible the high-gain temporal memory effect is reported for the p-BaTiO3. (C) 1998 Optical Society of America. C1 Allegheny Coll, Dept Phys, Meadville, PA 16335 USA. Grove City High Sch, Grove City, PA USA. USN, Res Lab, Naval Ctr Space Technol, Washington, DC 20375 USA. RP Statman, D (reprint author), Allegheny Coll, Dept Phys, Meadville, PA 16335 USA. NR 21 TC 1 Z9 1 U1 0 U2 0 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 577 EP 585 DI 10.1364/JOSAB.15.000577 PG 9 WC Optics SC Optics GA YX192 UT WOS:000072015600008 ER PT J AU Bowman, SR Rabinovich, WS Beadie, G Kirkpatrick, SM Katzer, DS Ikossi-Anastasiou, K Adler, CL AF Bowman, SR Rabinovich, WS Beadie, G Kirkpatrick, SM Katzer, DS Ikossi-Anastasiou, K Adler, CL TI Characterization of high performance integrated optically addressed spatial light modulators SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID MULTIPLE-QUANTUM-WELLS; PHOTOREFRACTIVE DEVICES; RESOLUTION; TRANSPORT AB An improved design for optically addressed multiple-quantum-well spatial light modulators is reported. These integrated AlGaAs modulators are of high optical quality and are simple to fabricate. They exhibit excellent performance characteristics such as 10:1 reflection contrast ratio, 1.5% diffraction efficiency, 7-mu m spatial resolution, and illumination sensitivity less than 1 mu J/cm(2). Additionally, a new mode of operation is reported that dramatically improves the optical response of these devices at low frequencies. A new physical model is proposed that accurately describes the modulation process. (C) 1998 Optical Society of America. C1 USN, Res Lab, Div Opt Sci, Washington, DC 20375 USA. USN, Res Lab, Div Elect Sci & Technol, Washington, DC 20375 USA. Cleveland State Univ, Dept Phys, Cleveland, OH 44115 USA. RP Bowman, SR (reprint author), USN, Res Lab, Div Opt Sci, Code 5640, Washington, DC 20375 USA. RI Katzer, D. Scott/N-7841-2013 NR 17 TC 20 Z9 20 U1 0 U2 0 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 640 EP 647 DI 10.1364/JOSAB.15.000640 PG 8 WC Optics SC Optics GA YX192 UT WOS:000072015600015 ER PT J AU Blantz, RC Madias, NE Ziegler, T Mehta, RL Steiner, R Ward, DM McDonald, B Gabbai, FB AF Blantz, RC Madias, NE Ziegler, T Mehta, RL Steiner, R Ward, DM McDonald, B Gabbai, FB TI Pathophysiology of pre-renal azotemia - Discussion SO KIDNEY INTERNATIONAL LA English DT Editorial Material ID CONGESTIVE HEART-FAILURE; CHRONIC SODIUM DEPLETION; TUBULO-GLOMERULAR FEEDBACK; ANGIOTENSIN-II; NITRIC-OXIDE; TUBULOGLOMERULAR FEEDBACK; PROXIMAL TUBULE; RAT-KIDNEY; HOMEOSTATIC EFFICIENCY; ANTIOXIDANT THERAPY C1 Univ Calif San Diego, Dept Nephrol, Div Nephrol & Hypertens, San Diego, CA 92103 USA. New England Med Ctr, Div Nephrol, Boston, MA 02111 USA. Univ Calif San Diego, La Jolla, CA 92093 USA. USN, Med Ctr, Div Nephrol, San Diego, CA 92152 USA. Vet Affairs Med Ctr, Nephrol Sect, San Diego, CA 92161 USA. Vet Affairs Med Ctr, Nephrol Sect, La Jolla, CA USA. RP Blantz, RC (reprint author), Univ Calif San Diego, Dept Nephrol, Div Nephrol & Hypertens, San Diego, CA 92103 USA. FU NHLBI NIH HHS [HL48018]; NIDDK NIH HHS [DK28602] NR 72 TC 36 Z9 37 U1 0 U2 0 PU BLACKWELL SCIENCE INC PI MALDEN PA 350 MAIN ST, MALDEN, MA 02148 USA SN 0085-2538 J9 KIDNEY INT JI Kidney Int. PD FEB PY 1998 VL 53 IS 2 BP 512 EP 523 DI 10.1046/j.1523-1755.2003_t01-1-00784.x PG 12 WC Urology & Nephrology SC Urology & Nephrology GA YU007 UT WOS:000071670500034 PM 9461116 ER PT J AU O'Sullivan, DW Millero, FJ AF O'Sullivan, DW Millero, FJ TI Continual measurement of the total inorganic carbon in surface seawater SO MARINE CHEMISTRY LA English DT Article; Proceedings Paper CT 1st International Meeting on Carbon Dioxide in the Oceans CY JAN, 1996 CL MAYAGUEZ, PUERTO RICO DE seawater; analytical; inorganic carbon; method ID HIGH-PRECISION MEASUREMENTS; ALTERNATE DETECTION METHODS; HIGH-ACCURACY MEASUREMENTS; POTENTIOMETRIC TITRATION; DIOXIDE; ALKALINITY; CALIBRATION; SYSTEM; MARINE; OCEAN AB An automated sampling and analysis system was developed to determine the total inorganic carbon (TCO2) in seawater. Measurements are performed on subsamples taken from the shipboard flowing seawater line. The flowing TCO2 system (FTCO2) automatically acidifies and strips the CO2 out of a known volume of sea water and determines the concentration by integrating the infra red (IR) absorbance. Laboratory results have demonstrated an analytical precision of 2-5 mu M in TCO2 for this system, Intercomparison of TCO2 measurements with the FTCO2 system and the SOMMA (single operator multimetabolic analyzer) agreed within their respective uncertainties. The TCO2 in surface seawater was determined continually on the flowing seawater line aboard the R/V Thompson in the Arabian Sea. The average difference between the TCO2 determined on surface seawater with the flowing system and the SOMMA was 6.5 +/- 8.7 mu M. Measurements made with the flowing system on CRMs agreed to +/-3 mu M with the assigned value. TCO2 in surface waters in the Arabian Sea varied by as much as 40 mu M on short spatial and temporal scales. Although the accuracy of the present design of the FTCO2 system is not as good as the SOMMA, the surface TCO2 variability with time and space is captured with the FTCO2 system and is completely missed by discrete measurements made on CTD casts. Continual measurements of TCO2 will be valuable in characterizing the temporal and spatial changes in the carbon dioxide system in surface ocean waters. (C) 1998 Elsevier Science B.V. C1 USN Acad, Dept Chem, Annapolis, MD 21401 USA. Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Miami, FL 33149 USA. RP O'Sullivan, DW (reprint author), USN Acad, Dept Chem, 572 Holloway Rd, Annapolis, MD 21401 USA. OI O'Sullivan, Daniel/0000-0001-9104-5703 NR 21 TC 33 Z9 33 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-4203 J9 MAR CHEM JI Mar. Chem. PD FEB PY 1998 VL 60 IS 1-2 BP 75 EP 83 DI 10.1016/S0304-4203(97)00079-0 PG 9 WC Chemistry, Multidisciplinary; Oceanography SC Chemistry; Oceanography GA ZM128 UT WOS:000073507500007 ER PT J AU Perez-Prado, MT McNelley, TR Ruano, OA Gonzalez-Doncel, G AF Perez-Prado, MT McNelley, TR Ruano, OA Gonzalez-Doncel, G TI Microtexture evolution during annealing and superplastic deformation of Al-5 pct Ca-5 pct Zn SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article ID ALUMINUM-MAGNESIUM ALLOY; SHEET ALLOY AB The microtexture and grain boundary misorientation distributions (i.e., mesotexture) of the superplastic alloy Al-5 pct Ca-5 pct Zn have been investigated in the as-processed condition, after annealing at 520 degrees C (for times ranging from 7 minutes to 90 hours) and after tensile straining in the transverse direction (TD). Three different superplastic straining conditions were considered: 550 degrees C/10(-2) s(-1), 550 degrees C/10(-1) s(-1), and 400 degrees C/10(-2) s(-1). Microtexture data were obtained by means of computer-aided electron backscatter diffraction analysis methods. The retention of the deformation texture of the as-received material and the development of an increasingly bimodal grain boundary misorientation distribution following static annealing are consistent with the occurrence of recovery and continuous recrystallization. During superplastic straining, deformation texture components are also retained, but with a change in the grain boundary misorientation distribution toward random, indicating that grain switching occurs during grain boundary sliding (GBS). At the midlayer, however, a change from an initial texture component near the Cu-type texture component toward the Brass texture component, {011}<211>, was observed even as the misorientation distribution became more random. This change in texture component is associated with the occurrence of single slip during superplastic flow. C1 CSIC, Ctr Nacl Invest Met, Dept Met Phys, Madrid 28040, Spain. USN, Postgrad Sch, Dept Mech Engn, Monterey, CA 93943 USA. RP CSIC, Ctr Nacl Invest Met, Dept Met Phys, Madrid 28040, Spain. RI Perez-Prado, Maria Teresa/M-2050-2014 OI Perez-Prado, Maria Teresa/0000-0003-0758-2851 NR 22 TC 26 Z9 26 U1 0 U2 1 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1073-5623 EI 1543-1940 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD FEB PY 1998 VL 29 IS 2 BP 485 EP 492 DI 10.1007/s11661-998-0129-7 PG 8 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA YZ133 UT WOS:000072223600008 ER PT J AU Miller, TA AF Miller, TA TI Provider assumptions should be reconsidered SO MILITARY MEDICINE LA English DT Letter ID PHYSICIAN C1 USN, MC, Washington, DC 20350 USA. RP Miller, TA (reprint author), USN, MC, Washington, DC 20350 USA. NR 4 TC 0 Z9 0 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 IV EP IV PG 1 WC Medicine, General & Internal SC General & Internal Medicine GA YX190 UT WOS:000072015400001 PM 9503889 ER PT J AU White, MR AF White, MR TI Hospitalization rates of tuberculosis in US Navy enlisted personnel: A 15-year perspective SO MILITARY MEDICINE LA English DT Article ID UNITED-STATES; INFECTION; EPIDEMIOLOGY AB The epidemiology of tuberculosis in this country is changing because of a combination of biological and social factors. The recent use of DNA fingerprinting of Mycobacterium tuberculosis using restriction-fragment-length polymorphism analysis has suggested that nearly one-third of new cases of tuberculosis being reported in a large metropolitan city is a result of recent infection. The immunosuppression of individuals with the human immunodeficiency virus and the prevalence of multiple drug-resistant tuberculosis has resulted in a renewed interest in the epidemiology and prevention of this disease. To determine the magnitude of the problem in the U.S. Navy enlisted population, a computer search of more than one million inpatient hospitalization records from January 1980 to December 1994 was performed. Total first hospitalization rates for all cases of tuberculosis during this period ranged from 2.2 per 100,000 person-years at risk in white females to 27.5 per 100,000 person-years in males, race "other" (includes mostly Filipinos and Asian-Americans). First hospitalization rates across all cases of tuberculosis declined during this period from a high of 8.7 per 100,000 in 1980 to a low of 2.2 per 100,000 in 1994. C1 Naval Hlth Res Ctr, Med Informat Syst & Operat Res Dept, San Diego, CA 92186 USA. RP White, MR (reprint author), Naval Hlth Res Ctr, Med Informat Syst & Operat Res Dept, POB 85122, San Diego, CA 92186 USA. NR 18 TC 9 Z9 9 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 71 EP 75 PG 5 WC Medicine, General & Internal SC General & Internal Medicine GA YX190 UT WOS:000072015400007 PM 9503895 ER PT J AU Gramzinski, RA Millan, CLB Obaldia, N Hoffman, SL Davis, HL AF Gramzinski, RA Millan, CLB Obaldia, N Hoffman, SL Davis, HL TI Immune response to a hepatitis B DNA vaccine in Aotus monkeys: A comparison of vaccine formulation, route, and method of administration SO MOLECULAR MEDICINE LA English DT Article ID DIRECT GENE-TRANSFER; CYTOTOXIC T-LYMPHOCYTES; PLASMID DNA; RHESUS-MONKEYS; VIRUS; IMMUNIZATION; INDUCTION; MUSCLE; CELLS; EXPRESSION AB Background: Attempts to optimize DNA vaccines in mice include using different routes of administration and different formulations. It may be more relevant to human use to carry such studies out in nonhuman primates. Here we compare different approaches to delivery of a DNA vaccine against the hepatitis B virus (HBV) in Aotus monkeys. Materials and Methods: Thirty-two adult Aotus l. lemurinus monkeys divided into 8 groups of four were immunized with 400 mu g of a DNA vaccine which encoded hepatitis B surface antigen (HBsAg). DNA in saline was administered by intradermal (ID) or intramuscular (IM) injection with needle and syringe, LM injection with the Biojector(R) needleless injection system or combined ID (needle) and IM (Biojebor). DNA formulated with cationic liposomes (CellFECTIN)(R) was injected IM with needle or Biojector. DNA with added E. coli DNA (100 mu g) was injected IM with the Biojector or ID. A ninth group of 4 monkeys was injected LM (needle) with Engerix-B, a commercial vaccine containing recombinant HBsAg (10 mu g) adsorbed onto alum. Monkeys were boosted in an identical fashion to their prime at 8 weeks, but all received the protein vaccine (Engerix-B) at 16 weeks. Sera was assessed for antibodies against HBsAg (anti-HBs) by enzyme-linked imunosorbent assay (ELISA). Results: The primary humoral response induced by IM delivery of the DNA vaccine was very poor. In most cases there was no detectable anti-HBs even after 2 DNA doses but the kinetics of the response to subsequent protein indicated that a memory B cell response had been induced. In contrast, following IM-administration of DNA using the Biojector, detectable anti-HBs were observed in 3 of 8 animals and evidence for immunological priming was apparent in an additional 4 of the 8 monkeys. ID injection of DNA vaccine in saline induced a potent antibody response which was augmented 6-fold by the addition of E. coli DNA. Combining ID and IM administration did not improve humoral immunity over ID injection alone. Conclusions: For immunization of primates with DNA vaccines, ID may be a preferable route to LM, although it is not clear whether the Aotus monkey is a relevant model for humans in this respect. Nevertheless, the use of the Biojector needleless injection system may improve responses with IM delivery of DNA vaccines. As well, the immunostimulatory action of E. coli DNA may be used to augment the humoral response induced by a DNA vaccine. C1 Ottawa Civic Hosp, Loeb Res Inst, Ottawa, ON K1Y 4E9, Canada. Ottawa Civic Hosp, Fac Hlth Sci, Ottawa, ON K1Y 4E9, Canada. Ottawa Civic Hosp, Fac Med, Ottawa, ON K1Y 4E9, Canada. Promed Trading Inc, Panama City, Panama. Gorgas Mem Lab, Panama City, Panama. USN, Med Res Inst, Malaria Program, Rockville, MD USA. RP Davis, HL (reprint author), Ottawa Civic Hosp, Loeb Res Inst, 725 Parkdale Ave, Ottawa, ON K1Y 4E9, Canada. EM hdavis@lri.ca RI Obaldia, Nicanor/O-8460-2015; OI Obaldia, Nicanor/0000-0002-3711-9449 NR 38 TC 63 Z9 65 U1 0 U2 5 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 1076-1551 J9 MOL MED JI Mol. Med. PD FEB PY 1998 VL 4 IS 2 BP 109 EP 118 PG 10 WC Biochemistry & Molecular Biology; Cell Biology; Medicine, Research & Experimental SC Biochemistry & Molecular Biology; Cell Biology; Research & Experimental Medicine GA ZC168 UT WOS:000072547600005 PM 9508788 ER PT J AU Gammon, D AF Gammon, D TI High-resolution spectroscopy of individual quantum dots in wells SO MRS BULLETIN LA English DT Article ID EXCITONS; GAAS; PHOTOLUMINESCENCE; RELAXATION C1 USN, Res Lab, Washington, DC 20375 USA. RP Gammon, D (reprint author), USN, Res Lab, Code 6876,4555 Overlook Ave SW, Washington, DC 20375 USA. EM gammon@bloch.nrl.nvy.mil NR 23 TC 1 Z9 1 U1 1 U2 4 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 0883-7694 J9 MRS BULL JI MRS Bull. PD FEB PY 1998 VL 23 IS 2 BP 44 EP 48 PG 5 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA YX197 UT WOS:000072016100019 ER PT J AU Alouani, AT Rice, TR AF Alouani, AT Rice, TR TI On optimal synchronous and asynchronous track fusion SO OPTICAL ENGINEERING LA English DT Article DE sensor fusion; Kalman filtering; track fusion; synchronous; asynchronous; optimization AB In practice, multisensor systems use dissimilar sensors that may have different data rates. Such sensors may also have inherent delays due to multitasking as well as communication delays between the sensor platform and a remote central processing site. Track fusion algorithms are presented that are valid for asynchronous sensors (the sensors have different data rates and different delays) as well as synchronous sensors (all of the sensors take measurements at the same time and the same rate with no delays). The asynchronous track fusion problem is formulated and solved first. Then the synchronous track fusion problem is obtained as a special case of the asynchronous one. Finally, using simulated target tracks, the performance of the asynchronous track fusion (ASTF) algorithm is analyzed and compared to an existing track fusion algorithm. Different sensor data rates and communication delays are used in the simulations. It is found that the ASTF algorithm outperforms its counterpart and is able to handle relatively large communication delays. The results presented set the foundation for deriving optimal track fusion algorithms when taking into account realistic constraints such as sensors with different data rates and different communication and/or processing delays. The results can also be used as a benchmark to evaluate existing suboptimal track fusion algorithms. (C) 1998 Society of Photo-Optical Instrumentation Engineers. C1 Tennessee Technol Univ, Dept ECE, Cookeville, TN 38505 USA. USN, Ctr Surface Warfare, Syst Res & Technol Dept, Dahlgren Div, Dahlgren, VA 22448 USA. RP Tennessee Technol Univ, Dept ECE, Cookeville, TN 38505 USA. EM ata7303@tntech.edu NR 7 TC 18 Z9 29 U1 0 U2 2 PU SPIE-SOC PHOTO-OPTICAL INSTRUMENTATION ENGINEERS PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98225 USA SN 0091-3286 EI 1560-2303 J9 OPT ENG JI Opt. Eng. PD FEB PY 1998 VL 37 IS 2 BP 427 EP 433 DI 10.1117/1.601628 PG 7 WC Optics SC Optics GA YX568 UT WOS:000072053600008 ER PT J AU Friebele, EJ Putnam, MA Patrick, HJ Kersey, AD Greenblatt, AS Ruthven, GP Krim, MH Gottschalck, KS AF Friebele, EJ Putnam, MA Patrick, HJ Kersey, AD Greenblatt, AS Ruthven, GP Krim, MH Gottschalck, KS TI Ultrahigh-sensitivity fiber-optic strain and temperature sensor SO OPTICS LETTERS LA English DT Article ID BRAGG GRATINGS; DISCRIMINATION; GLASSES AB We report ultrahigh-sensitivity static strain sensing (noise equivalent strain less than or equal to 1.5 n epsilon rms) by two fiber etalon cavities made from silica and fluoride fibers. The anomalous thermo-optic coefficient of fluoride glass fibers allows for determination of thermal and laser drift. This sensor is also capable of simultaneous strain and temperature measurement, with errors in strain and temperature of 6.4% and 0.68%, respectively. C1 USN, Res Lab, Div Opt Sci, Washington, DC 20375 USA. Hughes Danbury Opt Syst, Danbury, CT 06810 USA. RP Friebele, EJ (reprint author), USN, Res Lab, Div Opt Sci, Washington, DC 20375 USA. NR 9 TC 15 Z9 15 U1 2 U2 5 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 222 EP 224 DI 10.1364/OL.23.000222 PG 3 WC Optics SC Optics GA YU188 UT WOS:000071691100026 PM 18084466 ER PT J AU Hunsaker, DH AF Hunsaker, DH TI Approaches to otolaryngic allergy emergencies SO OTOLARYNGOLOGIC CLINICS OF NORTH AMERICA LA English DT Article ID ANAPHYLAXIS; IMMUNOTHERAPY AB The otolaryngic allergist should take every measure possible to prevent reactions during testing and treatment of the allergic patient. Because the risk of this rare complication cannot be completely eliminated, however, it is essential to be prepared for prompt recognition and proper treatment of an anaphylactic emergency. An emergency set, including airway management tools, oxygen, intravenous materials, and proper medication, is essential. The entire office staff should be educated to cope with the emergency. Finally, a medication history must be repeated at intervals to detect patients who are receiving beta blockers to either remove them from the patients' treatment regimen or to prepare for the special treatment of the patients on beta blockers. C1 USN, Med Ctr, Dept Otolaryngol, San Diego, CA 92152 USA. Univ Calif San Diego, Dept Surg, La Jolla, CA 92093 USA. Uniformed Serv Sch Hlth Sci, Bethesda, MD USA. RP Hunsaker, DH (reprint author), Suite 200,34520 Bob Wilson Dr, San Diego, CA 92134 USA. NR 49 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 0030-6665 J9 OTOLARYNG CLIN N AM JI Otolaryngol. Clin. N. Am. PD FEB PY 1998 VL 31 IS 1 BP 207 EP + DI 10.1016/S0030-6665(05)70039-6 PG 15 WC Otorhinolaryngology SC Otorhinolaryngology GA ZA870 UT WOS:000072410300016 PM 9530687 ER PT J AU Batts, KF Munter, DW AF Batts, KF Munter, DW TI Metoclopramide toxicity in an infant SO PEDIATRIC EMERGENCY CARE LA English DT Article DE metoclopramide; toxicity; overdose; adverse reactions ID EXTRAPYRAMIDAL REACTIONS; CANCER-CHEMOTHERAPY; CHILDREN AB Metoclopramide (4-amino-5-chloro-N-2-methoxybenzamide) is a central and peripheral acting dopamine antagonist. It also stimulates motility in the upper gastrointestinal tract and increases lower esophageal sphincter pressure. In the pediatric population, it is used extensively as an antiemetic and in the treatment of gastroesophageal reflux disease. The case of a six-month-old infant who was accidentally overdosed,vith 24 mg (3 mg/kg) of metoclopramide within a nine-hour period is presented. The patient demonstrated toxic extrapyramidal effects. There have been multiple early reports in the European literature of acute extrapyramidal reactions in the pediatric population, but no reports of toxicity exist in the current emergency medicine literature. C1 USN, Med Ctr, Dept Emergency Med, Portsmouth, VA 23708 USA. RP Batts, KF (reprint author), USN, Med Ctr, Dept Emergency Med, Portsmouth, VA 23708 USA. NR 17 TC 15 Z9 16 U1 1 U2 1 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 USA SN 0749-5161 J9 PEDIATR EMERG CARE JI Pediatr. Emerg. Care PD FEB PY 1998 VL 14 IS 1 BP 39 EP 41 DI 10.1097/00006565-199802000-00011 PG 3 WC Emergency Medicine; Pediatrics SC Emergency Medicine; Pediatrics GA YY491 UT WOS:000072151900011 PM 9516631 ER PT J AU Caviness, JA Tucker, MH Pia, SK Tam, DA AF Caviness, JA Tucker, MH Pia, SK Tam, DA TI Hydrocephalus as a possible early symptom in a child with a spinal cord tumor SO PEDIATRIC NEUROLOGY LA English DT Article AB Spinal cord tumors are relatively uncommon in children. These tumors have been associated with increased intracranial pressure in both children and adults. An infant presented initially with hydrocephalus and subsequently developed symptoms consistent with spinal cord abnormalities. Various proposed etiologies for increased intracranial pressure in spinal cord tumors are presented. Spinal cord tumors should be considered in the presence of childhood hydrocephalus and increased intracranial pressure without a clearly defined etiology. (C) 1998 by Elsevier Science Inc. All rights reserved. C1 USN, Dept Clin Invest, Med Ctr, San Diego, CA 92134 USA. USN, Dept Pediat, Med Ctr, San Diego, CA 92134 USA. Univ Calif San Diego, Div Child Neurol, San Diego, CA 92103 USA. Uniformed Serv Univ Hlth Sci, Bethesda, MD 20814 USA. RP Tam, DA (reprint author), USN, Dept Clin Invest, Med Ctr, 34800 Bob Wilson Dr, San Diego, CA 92134 USA. NR 12 TC 7 Z9 7 U1 0 U2 0 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 0887-8994 J9 PEDIATR NEUROL JI Pediatr. Neurol. PD FEB PY 1998 VL 18 IS 2 BP 169 EP 171 DI 10.1016/S0887-8994(97)00158-6 PG 3 WC Clinical Neurology; Pediatrics SC Neurosciences & Neurology; Pediatrics GA ZB268 UT WOS:000072454000011 PM 9535305 ER PT J AU Feldman, JL Bickham, SR Engel, GE Davidson, BN AF Feldman, JL Bickham, SR Engel, GE Davidson, BN TI Modes in amorphous silicon SO PHILOSOPHICAL MAGAZINE B-PHYSICS OF CONDENSED MATTER STATISTICAL MECHANICS ELECTRONIC OPTICAL AND MAGNETIC PROPERTIES LA English DT Article; Proceedings Paper CT 6th International Workshop on Disordered Systems CY MAR 03-06, 1997 CL ANDALO, ITALY SP Univ Trento, Dipartiemento Fis, Grp Nazl Struttura Mat, Consiglio Nazl Ric, Cassa Risparmio Trento & Rovereto ID THERMAL-CONDUCTIVITY; COMPUTER-SIMULATION; MOLECULAR-DYNAMICS; GENERATION; SI AB We discuss how the vibrational modes in an amorphous material can be characterized by various correlation functions. The spectrum of modes can be expected to contain both extended and localized states separated by mobility edges. The inverse participation ratio can be used as a measure of localization. To examine the vibrational modes in more detail, we propose to study mod;li of Fourier transforms of powers of the eigenvector components. We have applied the analysis to vibrational modes of amorphous silicon. The structural and potential models that we use are based on the Wooten-Winer-Weaire bond-switching algorithm and Stillinger-Weber classical potential. The structural models are cubic supercells, periodically repealed. Whereas models ranging in size from 216 to 4096 atoms have been studied, only the 4096-atom model results are included here. In the analysis, we employ only q vectors that are consistent with the boundary conditions used to obtain the modes. Upon averaging over q-vector direction, systematic dependences result. The structural aspects of the model are briefly considered. In particular, no unusual structural ordering has been detected in the pair distribution function for the 4096-atom model. C1 USN, Res Lab, Washington, DC 20375 USA. RP Feldman, JL (reprint author), USN, Res Lab, Washington, DC 20375 USA. NR 10 TC 5 Z9 5 U1 0 U2 2 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON EC4A 3DE, ENGLAND SN 0141-8637 J9 PHILOS MAG B JI Philos. Mag. B-Phys. Condens. Matter Stat. Mech. Electron. Opt. Magn. Prop. PD FEB PY 1998 VL 77 IS 2 BP 507 EP 512 DI 10.1080/13642819808204979 PG 6 WC Materials Science, Multidisciplinary; Mechanics; Physics, Applied; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA YW812 UT WOS:000071976500036 ER PT J AU Bickham, SR Feldman, JL AF Bickham, SR Feldman, JL TI Molecular dynamics simulations of vibrational lifetimes in amorphous silicon SO PHILOSOPHICAL MAGAZINE B-PHYSICS OF CONDENSED MATTER STATISTICAL MECHANICS ELECTRONIC OPTICAL AND MAGNETIC PROPERTIES LA English DT Article; Proceedings Paper CT 6th International Workshop on Disordered Systems CY MAR 03-06, 1997 CL ANDALO, ITALY SP Univ Trento, Dipartiemento Fis, Grp Nazl Struttura Mat, Consiglio Nazl Ric, Cassa Risparmio Trento & Rovereto ID PHONONS; SI; TEMPERATURE; DECAY; GE AB Recent theoretical and time resolved Raman studies disagree on the lifetime of high energy vibrational modes in amorphous silicon. The latter suggests that the lifetime increases with increasing frequency and is of the order of 10 ns for the highest frequency modes, while the former predicts a picosecond timescale that follows the two-phonon density of states. Here we present the results of molecular dynamics simulations which are complementary to the perturbative calculations. At different temperatures, kinetic energy is put into selected modes of vibration in 216 and 4096 atom systems with periodic boundary conditions and the Stillinger-Weber potential. The lifetime of medium and high frequency modes is found to be of the order of 10 ps at 5, 10 and 30 K, in qualitative agreement with the perturbative calculations. C1 USN, Res Lab, Complex Syst Theory Branch, Washington, DC 20375 USA. RP Bickham, SR (reprint author), USN, Res Lab, Complex Syst Theory Branch, Washington, DC 20375 USA. NR 13 TC 9 Z9 9 U1 0 U2 2 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON EC4A 3DE, ENGLAND SN 0141-8637 J9 PHILOS MAG B JI Philos. Mag. B-Phys. Condens. Matter Stat. Mech. Electron. Opt. Magn. Prop. PD FEB PY 1998 VL 77 IS 2 BP 513 EP 521 DI 10.1080/13642819808204980 PG 9 WC Materials Science, Multidisciplinary; Mechanics; Physics, Applied; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA YW812 UT WOS:000071976500037 ER PT J AU Ngai, KL Rendell, RW AF Ngai, KL Rendell, RW TI A coupling model analysis of dynamics of concentrated colloidal suspensions SO PHILOSOPHICAL MAGAZINE B-PHYSICS OF CONDENSED MATTER STATISTICAL MECHANICS ELECTRONIC OPTICAL AND MAGNETIC PROPERTIES LA English DT Article; Proceedings Paper CT 6th International Workshop on Disordered Systems CY MAR 03-06, 1997 CL ANDALO, ITALY SP Univ Trento, Dipartiemento Fis, Grp Nazl Struttura Mat, Consiglio Nazl Ric, Cassa Risparmio Trento & Rovereto ID GLASS TRANSFORMATION TEMPERATURE; NEUTRON-SCATTERING; CONDUCTIVITY SPECTRA; FORMING SYSTEMS; ION DYNAMICS; PHASE-SPACE; RELAXATION; TRANSITION; DIFFUSION; TRANSPORT AB Recent dynamic light scattering measurement on concentrated suspensions of 'hard-sphere' colloidal particles by Segre and Pusey (1996, Phys. Rev. Lett., 77, 771) are compared with the theoretical results calculated by the coupling model. The calculated normalized intermediate scattering function decays exponentially at both short and long times, f(Q, short t) proportional to exp[-D-S(Q)Q(2)t] and f(Q, long t) proportional to exp [-D-L(Q)Q(2)t] respectively, with D-L(Q) and D-S(Q) having the same Q dependence. The ratio D-L(Q)/D-S(Q) decreases rapidly with volume fraction phi. At intermediate times, the decay of f(Q, t) is slower and nonexponential, becomes increasing slower and extends to longer times as phi increases. There is good agreement between theory and experiment. It is also pointed out that the diffusional dynamics found in concentrated colloidal suspensions are general and shared by other densely packed interacting systems. C1 USN, Res Lab, Washington, DC 20375 USA. RP Ngai, KL (reprint author), USN, Res Lab, Washington, DC 20375 USA. NR 37 TC 23 Z9 23 U1 1 U2 2 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON EC4A 3DE, ENGLAND SN 0141-8637 J9 PHILOS MAG B JI Philos. Mag. B-Phys. Condens. Matter Stat. Mech. Electron. Opt. Magn. Prop. PD FEB PY 1998 VL 77 IS 2 BP 621 EP 631 DI 10.1080/13642819808204989 PG 11 WC Materials Science, Multidisciplinary; Mechanics; Physics, Applied; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA YW812 UT WOS:000071976500046 ER PT J AU Warren, RW Dunlap, BI AF Warren, RW Dunlap, BI TI Effect of exchange-correlation functionals and symmetry constraints of electronic structure on the trajectories of reactive molecular collisions SO PHYSICAL REVIEW A LA English DT Article ID POTENTIAL-ENERGY SURFACES; HARTREE-FOCK; FRACTIONAL OCCUPATIONS; LINEAR COMBINATION; CHI-ALPHA; DYNAMICS; SYSTEMS; BOND; GRADIENTS; APPROXIMATIONS AB Two computationally efficient implementations of first-principles molecular dynamics are examined using the reactive scattering of two linear ozone molecules to yield three molecules of oxygen. These methods are based on Kohn-Sham density-functional theory in which the charge density is fitted variationally. The linear combination of Gaussian-type orbitals approach is used to construct the orbital and local-potential basis sets. The first method is a completely general approach requiring variational fitting of the exchange-correlation energy density on a grid of points. The second method avoids the grid of joints, but is restricted to the X alpha functional. Key elements of the dynamics calculation include self-consistent-field convergence at each time step, use of fractional occupation numbers to model the configurational mixing that occurs upon bond formation or dissociation, and accurate analytic evaluation of the appropriate forces acting upon the nuclei. Trajectories computed using modern local-density and gradient-corrected functionals, as well as X alpha (alpha = 0.6667) treated analytically, are compared. It is found that reactive trajectories obtained using analytic X alpha and the generalized gradient approximation are very similar when the initial kinetic energy is well above threshold for reaction. Under similar conditions, trajectories resulting from use of modern local-density functionals exhibit somewhat distinctive behavior. These results suggest that the particularly efficient analytic X alpha approach is suitable for preliminary investigations of chemical reactions using first-principles molecular dynamics based on density-functional theory. [S1050-2947(98)02502-5]. C1 USN, Theoret Chem Sect, Res Lab, Washington, DC 20375 USA. RP Warren, RW (reprint author), St Michaels Coll, Dept Chem, Winooski Pk, Colchester, VT 05439 USA. OI Dunlap, Brett/0000-0003-1356-6559 NR 53 TC 8 Z9 8 U1 1 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 FEB PY 1998 VL 57 IS 2 BP 899 EP 905 DI 10.1103/PhysRevA.57.899 PG 7 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA YW253 UT WOS:000071913800034 ER PT J AU Zheleznyak, AT Yakovenko, VM Drew, HD Mazin, II AF Zheleznyak, AT Yakovenko, VM Drew, HD Mazin, II TI Phenomenological interpretations of the ac Hall effect in the normal state of YBa2Cu3O7 SO PHYSICAL REVIEW B LA English DT Article ID T-C SUPERCONDUCTORS; HIGH-TEMPERATURE SUPERCONDUCTORS; ANGLE-RESOLVED PHOTOEMISSION; FERMI-SURFACE; ENERGY-GAP; HOT-SPOTS; CRYSTAL; METALS; MAGNETORESISTANCE; ANISOTROPY AB ac and de magnetotransport data in the normal state of YBa2Cu3O7 are analyzed within Fermi-liquid and non-Fermi-liquid models. In the Fermi-liquid analysis we use the Fermi surface deduced from band-structure calculations and angular-resolved photoemission experiments and assume that the electron relaxation rate varies over the Fermi surface. The non-Fermi-liquid models are the two-dimensional Luttinger-liquid model and the charge-conjugation-symmetry model. We find that the existing experimental data can be adequately fit by any of these models. This work provides a framework for the analysis of experiments that may discriminate among these models. C1 Univ Maryland, Dept Phys, College Pk, MD 20742 USA. Univ Maryland, Ctr Superconduct Res, College Pk, MD 20742 USA. George Mason Univ, Washington, DC 20375 USA. USN, Res Lab, Washington, DC 20375 USA. RP Zheleznyak, AT (reprint author), Univ Maryland, Dept Phys, College Pk, MD 20742 USA. EM anatoley@glue.umd.edu; yakovenk@glue.umd.edu RI Yakovenko, Victor/A-7559-2008; Mazin, Igor/B-6576-2008; OI Yakovenko, Victor M./0000-0003-3754-1794 NR 57 TC 46 Z9 46 U1 0 U2 7 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 FEB 1 PY 1998 VL 57 IS 5 BP 3089 EP 3098 DI 10.1103/PhysRevB.57.3089 PG 10 WC Physics, Condensed Matter SC Physics GA YV538 UT WOS:000071835100065 ER PT J AU Carroll, TL Johnson, GA AF Carroll, TL Johnson, GA TI Synchronizing broadband chaotic systems to narrow-band signals SO PHYSICAL REVIEW E LA English DT Article ID OPTIMAL PERIODIC-ORBITS AB We show that it is possible to take a signal from a chaotic drive system, pass it through a bandpass filter, and still use it to synchronize a chaotic response system. Narrow-band chaotic signals should be less sensitive to channel distortion and noise, so filtering should be useful for chaotic communications schemes. [S1063-651X(98)05002-8]. C1 USN, Res Lab, Washington, DC 20375 USA. RP USN, Res Lab, Code 6343, Washington, DC 20375 USA. OI Carroll, Thomas/0000-0002-2371-2049 NR 25 TC 10 Z9 10 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0045 EI 2470-0053 J9 PHYS REV E JI Phys. Rev. E PD FEB PY 1998 VL 57 IS 2 BP 1555 EP 1558 DI 10.1103/PhysRevE.57.1555 PN A PG 4 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA YY127 UT WOS:000072116000049 ER PT J AU Krushelnick, K Ting, A Moore, CI Burris, HR AF Krushelnick, K Ting, A Moore, CI Burris, HR TI Large-amplitude radial-plasma-wave generation during high-intensity laser interactions with underdense plasmas SO PHYSICAL REVIEW E LA English DT Article ID WAKE-FIELD ACCELERATION; RAMAN SCATTERED-LIGHT; 2ND-HARMONIC GENERATION; ELECTRON ACCELERATION; PULSE; FREQUENCY; FILAMENTATION; EMISSION AB Forward-scattered radiation produced from the interaction of an ultraintense laser pulse (P similar to 2 TW) with underdense hydrogen and helium plasmas (n(e) approximate to 10(19) cm(-3)) is measured. The coherently Thomson scattered satellites of the second harmonic at off-axis scattering angles are observed to be significant, in contrast to observations in the directly forward direction. These results are likely due to the existence of large-amplitude radial plasma waves generated by ponderomotive forces as the laser pulse propagates through the plasma. C1 Cornell Univ, Plasma Studies Lab, Ithaca, NY 14853 USA. USN, Res Lab, Div Plasma Phys, Washington, DC 20375 USA. RP Krushelnick, K (reprint author), Cornell Univ, Plasma Studies Lab, Ithaca, NY 14853 USA. NR 29 TC 2 Z9 2 U1 1 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD FEB PY 1998 VL 57 IS 2 BP 2475 EP 2478 DI 10.1103/PhysRevE.57.2475 PN B PG 4 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA YY128 UT WOS:000072116100077 ER PT J AU Schmitt, AJ Afeyan, BB AF Schmitt, AJ Afeyan, BB TI Time-dependent filamentation and stimulated Brillouin forward scattering in inertial confinement fusion plasmas SO PHYSICS OF PLASMAS LA English DT Article ID LASER-BEAM DEFLECTION; LIGHT; RADIATION; FLOW AB Numerical simulations of the temporal evolution of laser light filamentation and stimulated Brillouin forward scattering (SBFS); in plasmas, under conditions that are relevant to laser fusion, are presented and analyzed. Long term unsteady behavior of filaments is observed to be the norm. Temporal and spatial incoherence due to filamentation and SBFS are impressed upon time-independent incident laser beams. The bandwidth and angular divergence imposed upon the beam increase with the strength of the interaction. In addition, the spectrum of the transmitted light is redshifted by an amount that increases with the interaction strength. Spectral analysis of the transmitted light reveals that SBFS plays a role in the generation of the observed temporal incoherence. Incident beams with some spatial incoherence but no temporal smoothing are compared to those with ab initio temporal beam smoothing (TBS). Under typical conditions, TBS beams will undergo far less angular and spectral spreading and far less SBFS than unsmoothed beams. C1 USN, Res Lab, Div Plasma Phys, Washington, DC 20375 USA. Univ Calif Lawrence Livermore Natl Lab, Inst Laser Sci & Applicat, Livermore, CA 94551 USA. Univ Calif Lawrence Livermore Natl Lab, Dept Appl Sci, Livermore, CA 94551 USA. RP Schmitt, AJ (reprint author), USN, Res Lab, Div Plasma Phys, Washington, DC 20375 USA. NR 46 TC 80 Z9 82 U1 0 U2 6 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 FEB PY 1998 VL 5 IS 2 BP 503 EP 517 DI 10.1063/1.872733 PG 15 WC Physics, Fluids & Plasmas SC Physics GA YV530 UT WOS:000071834300022 ER PT J AU Santangelo, PG Ngai, KL Roland, CM AF Santangelo, PG Ngai, KL Roland, CM TI The coupling model approach to the terminal relaxation SO POLYMER LA English DT Article DE coupling; terminal relaxation; polymer ID MISCIBLE POLYMER BLEND; SEGMENTAL RELAXATION; MOLECULAR-WEIGHT; VISCOELASTIC PROPERTIES; TEMPERATURE-DEPENDENCE; COMPONENT DYNAMICS; INTERMOLECULAR COOPERATIVITY; THERMORHEOLOGICAL COMPLEXITY; EPOXIDIZED POLYISOPRENE; NEUTRON-SCATTERING AB Various predictions of the coupling model (CM) are known to be in agreement with observations of relaxation phenomena in polymers. However, as shown herein, when applied to the terminal relaxation, the model deviates from experimental data for monodisperse polymers; to wit the shape of the terminal relaxation spectrum does not conform to the CM equation. Nevertheless, the main premise of the model-that the dynamics transition from intermolecularly uncorrelated to entanglement-coupled relaxation at a temperature-independent crossover time-is supported by the data. Specifically, it is shown that the continuity condition of the model, relating the magnitudes of the non-cooperative and cooperative relaxation times, can be determined numerically to yield predictions for the molecular weight and temperature dependencies of the terminal viscosity in agreement with experiment. Previously the derivation of this continuity relation relied on the assumption of a specific form for the relaxation function's shape. The discrepancy concerning the shape of the relaxation function is apparently due to alleviation of the entanglement constraints, with consequent time-dependence of the coupling parameter. Previously, the coupling parameter has been regarded as strictly constant; however, at times approaching and longer than the terminal relaxation time, mitigation of the lateral constraints causes a decrease in the degree of intermolecular cooperativity, and hence in the coupling strength. The deviation of experimental spectra from the model's prediction is likely due to the neglect of this fluctuation in the severity of entanglements. Published by Elsevier Science Ltd. C1 USN, Res Lab, Div Chem, Washington, DC 20375 USA. RP Santangelo, PG (reprint author), USN, Res Lab, Div Chem, Code 6120, Washington, DC 20375 USA. NR 63 TC 13 Z9 14 U1 0 U2 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0032-3861 J9 POLYMER JI Polymer PD FEB PY 1998 VL 39 IS 3 BP 681 EP 687 DI 10.1016/S0032-3861(97)00315-7 PG 7 WC Polymer Science SC Polymer Science GA YM767 UT WOS:000071098800021 ER PT J AU Chapman, RD Fronabarger, JW AF Chapman, RD Fronabarger, JW TI A convenient correlation for prediction of binary eutectics involving organic explosives SO PROPELLANTS EXPLOSIVES PYROTECHNICS LA English DT Article ID EXCESS THERMODYNAMIC FUNCTIONS; SYSTEMS AB The best predictor of the extent of eutectic formation between explosive ingredients is the difference between their reciprocal melting temperatures (r(2)=0.838 among 74 examples). Though thermodynamic relationships such as van't Hoff's equation have come to be recognized in recent years as a basis for predicting eutectic behavior, a quantitative correlation to melting point differences as the major contributor to this behavior seems to have been unrecognized in the energetic materials community. The correlation for binary compositions has the form: In[X(solute)/X(solvent)] = -4077.04 Delta(T-m(-1))-0.0979, where solvent is defined as the lower-melting component. This correlation is derived on the basis of thermodynamic theory with simple approximations. C1 TPL Inc, Albuquerque, NM 87109 USA. Exotherm Inc, Sun Lakes, AZ 85248 USA. RP Chapman, RD (reprint author), USN, Air Warfare Ctr, Weapons Div, Res & Technol Grp, Code 4822C, China Lake, CA 93555 USA. NR 14 TC 5 Z9 5 U1 0 U2 0 PU WILEY-V C H VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 0721-3115 J9 PROPELL EXPLOS PYROT JI Propellants Explos. Pyrotech. PD FEB PY 1998 VL 23 IS 1 BP 50 EP 55 DI 10.1002/(SICI)1521-4087(199802)23:1<50::AID-PREP50>3.0.CO;2-E PG 6 WC Chemistry, Applied; Engineering, Chemical SC Chemistry; Engineering GA ZE699 UT WOS:000072821400010 ER PT J AU Bain, BK AF Bain, BK TI CT scans of first-break psychotic patients in good general health SO PSYCHIATRIC SERVICES LA English DT Article ID PSYCHIATRIC-PATIENTS AB A computed tomography (CT) scan of the head is often routine for patients with new-onset psychosis to rule out somatic causes. Charts of 127 such patients admitted to a major military medical center were examined. Most patients were young and otherwise in good health. Relationships were examined between CT scan findings and demographic variables, seizure history, neurological abnormalities, and discharge diagnosis. None of the 127 patients had an abnormal scan; four had incidental findings. Incidental findings were strongly associated with ethnic minority status but not with neurologic abnormalities, seizure history, or diagnosis. Findings suggest that routine CT scans for all newly psychotic military patients may not be warranted. C1 USN, Med Ctr, Dept Clin Invest, San Diego, CA 92134 USA. USN, Med Ctr, Dept Psychiat, San Diego, CA 92134 USA. RP Bain, BK (reprint author), USN, Med Ctr, Dept Clin Invest, 34800 Bob Wilson Dr, San Diego, CA 92134 USA. NR 8 TC 13 Z9 15 U1 0 U2 0 PU AMER PSYCHIATRIC ASSOCIATION PI WASHINGTON PA 1400 K ST NW, WASHINGTON, DC 20005 USA SN 1075-2730 J9 PSYCHIATR SERV JI Psychiatr. Serv. PD FEB PY 1998 VL 49 IS 2 BP 234 EP 235 PG 2 WC Health Policy & Services; Public, Environmental & Occupational Health; Psychiatry SC Health Care Sciences & Services; Public, Environmental & Occupational Health; Psychiatry GA YV307 UT WOS:000071810100016 PM 9575012 ER PT J AU Jones, TW Rudnick, L Jun, BI Borkowski, KJ Dubner, G Frail, DA Kang, H Kassim, NE McCray, R AF Jones, TW Rudnick, L Jun, BI Borkowski, KJ Dubner, G Frail, DA Kang, H Kassim, NE McCray, R TI 10(51) Ergs: The Evolution of Shell Supernova Remnants SO PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC LA English DT Review ID LARGE MAGELLANIC CLOUD; DIFFUSIVE PARTICLE-ACCELERATION; CASSIOPEIA-A SUPERNOVA; GAMMA-RAY EMISSION; RADIO-EMISSION; COSMIC-RAYS; X-RAY; HYDRODYNAMIC INSTABILITIES; CIRCUMSTELLAR INTERACTION; ASCA OBSERVATIONS AB This paper reports on the workshop "10(51) Ergs: The Evolution of Shell Supernova Remnants," hosted by the University of Minnesota, 1997 March 23-26. The workshop was designed to address fundamental dynamical issues associated with the evolution of shell supernova remnants and to understand better the relationships between supernova remnants and their environments. Although the title points only to classical, shell SNR structures, the workshop also considered dynamical issues involving X-ray-filled composite remnants and pulsar-driven shells, such as that in the Crab Nebula. Approximately 75 observers, theorists, and numerical simulators with wide-ranging interests attended the workshop. An even larger community helped through extensive on-line debates prior to the meeting to focus issues and galvanize discussion. In order to deflect thinking away from traditional patterns, the workshop was organized around chronological sessions for "very young," "young," "mature," and "old" remnants, with the implicit recognition that these labels are often difficult to apply. Special sessions were devoted to related issues in plerions and "thermal X-ray composites." Controversy and debate were encouraged. Each session also addressed some underlying, general physical themes: How are supernova remnant (SNR) dynamics and structures modified by the character of the circumstellar medium (CSM) and the interstellar medium (ISM), and vice versa? How are magnetic fields generated in SNRs and how do magnetic fields influence SNRs? Where and how are cosmic rays (electrons and ions) produced in SNRs, and how does their presence influence or reveal SNR dynamics? How does SNR blast energy partition into various components over time, and what controls conversion between components? In lieu of a proceedings volume, we present here a synopsis of the workshop in the form of brief summaries of the workshop sessions. The sharpest impressions from the workshop were the crucial and underappreciated roles that environments have on SNR appearance and dynamics and the critical need for broad-based studies to understand these beautiful but enigmatic objects. C1 Univ Minnesota, Dept Astron, Minneapolis, MN 55455 USA. N Carolina State Univ, Dept Phys, Raleigh, NC 27695 USA. Inst Astron & Fis Espacio, RA-1428 Buenos Aires, DF, Argentina. Natl Radio Astron Observ, Socorro, NM 87801 USA. Univ Washington, Dept Astron, Seattle, WA 98195 USA. USN, Res Lab, Washington, DC 20375 USA. Univ Colorado, JILA, Boulder, CO 80309 USA. RP Jones, TW (reprint author), Univ Minnesota, Dept Astron, 116 Church St SE, Minneapolis, MN 55455 USA. NR 114 TC 60 Z9 61 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-6280 EI 1538-3873 J9 PUBL ASTRON SOC PAC JI Publ. Astron. Soc. Pac. PD FEB PY 1998 VL 110 IS 744 BP 125 EP 151 DI 10.1086/316122 PG 27 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA ZB272 UT WOS:000072454400005 ER PT J AU Karle, J Huang, L Massa, L AF Karle, J Huang, L Massa, L TI Quantum crystallography, a technique for extending the concept of structure SO PURE AND APPLIED CHEMISTRY LA English DT Article; Proceedings Paper CT 20th IUPAC Symposium on the Chemistry of Natural Products CY SEP 15-20, 1996 CL CHICAGO, ILLINOIS SP IUPAC ID MEMBRANE AB A developing area of research concerns a technique for extracting quantum mechanically valid properties from X-ray diffraction experiments. Quantum mechanics and crystallography are joined through the fact that the electron distributions around atoms are the source of X-ray diffraction and electron density distributions are observables that lend themselves readily to quantum mechanical description. Direct contact with the X-ray diffraction data is made by equating the structure factor magnitudes, which are readily obtained from the measured X-ray diffraction intensities with the magnitudes of Fourier transforms of the quantum mechanical description of the electron distribution. The article concerns a further discussion of quantum crystallography and its implications. To create a quantum mechanical model, crystallographic information in the form of atomic positions is used. Since quantum crystallography is applicable to very large structures, methods for handling very large structures are described. C1 USN, Res Lab, Struct Matter Lab, Washington, DC 20375 USA. CUNY Hunter Coll, New York, NY 10021 USA. CUNY, Grad Ctr, New York, NY 10021 USA. RP Karle, J (reprint author), USN, Res Lab, Struct Matter Lab, Washington, DC 20375 USA. NR 8 TC 12 Z9 12 U1 0 U2 2 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0033-4545 J9 PURE APPL CHEM JI Pure Appl. Chem. PD FEB PY 1998 VL 70 IS 2 BP 319 EP 324 DI 10.1351/pac199870020319 PG 6 WC Chemistry, Multidisciplinary SC Chemistry GA ZU823 UT WOS:000074238800015 ER PT J AU Davis-Lunde, K Rudolph, DK Miller, RL Estess, RS AF Davis-Lunde, K Rudolph, DK Miller, RL Estess, RS TI MERMAID Optics System SO SEA TECHNOLOGY LA English DT Article C1 USN, Opt Program, Stennis Space Ctr, MS 39529 USA. USN, Oceanog Off, Stennis Space Ctr, MS 39529 USA. NASA, Earth Syst Sci Off, Stennis Space Ctr, MS USA. RP Davis-Lunde, K (reprint author), USN, Opt Program, Stennis Space Ctr, MS 39529 USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU COMPASS PUBL INC PI ARLINGTON PA SUITE 1000 1117 N 19 ST, ARLINGTON, VA 22209 USA SN 0093-3651 J9 SEA TECHNOL JI Sea Technol. PD FEB PY 1998 VL 39 IS 2 BP 10 EP + PG 6 WC Engineering, Ocean SC Engineering GA YZ655 UT WOS:000072276800002 ER PT J AU Meyer, JL Harrington, WB Agrawal, BN Song, GB AF Meyer, JL Harrington, WB Agrawal, BN Song, GB TI Vibration suppression of a spacecraft flexible appendage using smart material SO SMART MATERIALS & STRUCTURES LA English DT Article AB This paper presents the results of positive position feedback (PPF) control and linear-quadratic Gaussian (LQG) control for vibration suppression of a flexible structure using piezoceramics. Experiments were conducted on the US Naval Postgraduate School's flexible spacecraft simulator (FSS), which is comprised of a rigid central body and a flexible appendage. The objective of this research is to suppress the vibration of the flexible appendage. Experiments show that both control methods have unique advantages for vibration suppression. PPF control is effective in providing high damping for a particular mode and is easy to implement. LQG control provides damping to all modes; however, it cannot provide high damping for a specific mode. LQG control is very effective in meeting specific requirements, such as minimization of tip motion of a flexible beam, but at a higher implementation cost. C1 USN, Postgrad Sch, Dept Aeronaut & Astronaut, Monterey, CA 93943 USA. NR 10 TC 29 Z9 31 U1 0 U2 8 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0964-1726 J9 SMART MATER STRUCT JI Smart Mater. Struct. PD FEB PY 1998 VL 7 IS 1 BP 95 EP 104 DI 10.1088/0964-1726/7/1/011 PG 10 WC Instruments & Instrumentation; Materials Science, Multidisciplinary SC Instruments & Instrumentation; Materials Science GA ZB347 UT WOS:000072462500011 ER PT J AU Nee, SMF Cole, T AF Nee, SMF Cole, T TI Effects of depolarization of polarimetric components on null ellipsometry SO THIN SOLID FILMS LA English DT Article; Proceedings Paper CT 2nd International Conference on Spectroscopic Ellipsometry (ICSE-2) CY MAY 12-15, 1997 CL CHARLESTON, SOUTH CAROLINA DE depolarization; Mueller matrix; NE; RAE; PCSA; PSA ID NEAR-SPECULAR SCATTERING; POLARIZATION AB Depolarization of optical components degrades the performance of a polarimeter, especially in the short wavelength region. Expressions for the light intensity in a null ellipsometer (NE) and a polarizer-sample-analyzer (PSA) system with depolarization errors in all components are given. Errors in Psi and Delta using IVE are mainly caused by depolarization of the compensator. A sample consisting of a thin sapphire slab 0.8 mm thick was tested. Delta measured by NE were shown to be accurate even for sample depolarization as large as 0.3, while those measured by rotating-analyzer ellipsometry (RAE) were seriously affected by sample depolarization. Methods for measuring depolarization were devised. The measured depolarization increases with the slit-width of the monochromator and the aperture size of irises and decreases with increasing wavelength. Depolarization spectra measured using NE, RAE and transmittance agree with one another. Published by Elsevier Science S.A. C1 USN, Air Warfare Ctr, Weap Div, Res & Technol Grp,Phys Branch, China Lake, CA 93555 USA. RP Nee, SMF (reprint author), USN, Air Warfare Ctr, Weap Div, Res & Technol Grp,Phys Branch, China Lake, CA 93555 USA. NR 8 TC 22 Z9 22 U1 0 U2 3 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD FEB PY 1998 VL 313 BP 90 EP 96 DI 10.1016/S0040-6090(97)00776-1 PG 7 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA ZP520 UT WOS:000073761700015 ER PT J AU Gragg, RF AF Gragg, RF TI One-way propagation in weakly nonuniform media SO WAVE MOTION LA English DT Article AB A series of energy-conserving generalized rotations is applied to the Helmholtz equation for a weakly nonuniform one-dimensional medium. These transformations decouple the wave field, to arbitrary order in the strength of the nonuniformity, into counter-propagating modes with separately conserved energies. The result is asymptotic propagation without backscatter at arbitrary order. Low-order results coincide with the WKB form of the solution. Higher orders provide WKB modifications applicable to long-range propagation, e.g. in long time-of-flight applications or very-long baseline interferometry. The result is illustrated in a numerical example. Copyright (C) 1998 Elsevier Science B.V. C1 USN, Res Lab, Washington, DC 20375 USA. RP Gragg, RF (reprint author), USN, Res Lab, Washington, DC 20375 USA. NR 21 TC 6 Z9 6 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0165-2125 J9 WAVE MOTION JI Wave Motion PD FEB PY 1998 VL 27 IS 2 BP 95 EP 115 DI 10.1016/S0165-2125(97)00044-9 PG 21 WC Acoustics; Mechanics; Physics, Multidisciplinary SC Acoustics; Mechanics; Physics GA YT948 UT WOS:000071662600001 ER PT J AU Wahl, KJ Belin, M Singer, IL AF Wahl, KJ Belin, M Singer, IL TI A triboscopic investigation of the wear and friction of MoS2 in a reciprocating sliding contact SO WEAR LA English DT Article DE MoS2; sliding contact; triboscopy; friction ID BEAM-ASSISTED DEPOSITION; IMPLANTED 52100 STEEL; FILMS; BEHAVIOR; COATINGS; LUBRICATION; ENDURANCE; VACUUM AB Reciprocating sliding tests with ball-on-flat geometry were performed on a duplex coating at low speeds in moist air (RH = 60%). The coating, 55 nm MoS2 on 35 nm of TiN, was deposited by ion-beam assisted deposition onto a steel substrate. Friction coefficient (mu) and electrical contact resistance (R-c) measurements were recorded at similar to 2 mu m intervals along the track; these spatially resolved measurements were compared to the more commonly presented cycle-averaged values. The last-cycle tracks of several runs were also analyzed by a variety of microscopies and spectroscopies to identify compositions and determine thicknesses of films on the tracks and balls. R-c measurements, both averaged and spatially resolved, were more sensitive to coating damage and loss than mu measurements. In the averaged data, fluctuations in R-c were observed before fluctuations in mu. Spatially resolved data showed that local drops in R-c could be detected as early as 20% of life. Additionally, recovery of both high mu and low R-c regions, interpreted as healing of damage in the contact, occured. Friction coefficient data were insensitive to changes in MoS2 coating thickness; conversely, R-c followed wear track thickness and consequently may provide an in situ method of monitoring coating wear. (C) 1998 Published by Elsevier Science S.A. C1 USN, Res Lab, Washington, DC 20375 USA. Ecole Cent Lyon, Lab Tribol & Dynam Syst, F-69131 Ecully, France. RP Wahl, KJ (reprint author), USN, Res Lab, Code 6176, Washington, DC 20375 USA. EM wahl@stm2.nrl.navy.mil OI Wahl, Kathryn/0000-0001-8163-6964 NR 34 TC 63 Z9 63 U1 1 U2 11 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0043-1648 J9 WEAR JI Wear PD FEB PY 1998 VL 214 IS 2 BP 212 EP 220 DI 10.1016/S0043-1648(97)00246-9 PG 9 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA YZ626 UT WOS:000072272900010 ER PT J AU In, V Spano, ML Ding, MZ AF In, V Spano, ML Ding, MZ TI Maintaining chaos in high dimensions SO PHYSICAL REVIEW LETTERS LA English DT Article ID CRITICAL EXPONENT AB In dynamical systems, as a parameter is varied past a critical value, a chaotic attractor may be destroyed by a crisis. This attractor is replaced by a chaotic transient, which eventually leads to a different attractor. We present a method for maintaining chaotic dynamics after the crisis. The model, formulated for arbitrary dimensions, directs the phase space trajectory toward a target region near the periodic saddle orbit that mediates the crisis. It is used to maintain chaos numerically in the Ikeda map and experimentally in a magnetoelastic ribbon. [S0031-9007(97)05100-4]. C1 USN, Ctr Surface Warfare, W Bethesda, MD 20817 USA. Florida Atlantic Univ, Ctr Complex Syst, Boca Raton, FL 33431 USA. Florida Atlantic Univ, Dept Math Sci, Boca Raton, FL 33431 USA. RP In, V (reprint author), USN, Ctr Surface Warfare, 9500 MacArthur Blvd,Code 684, W Bethesda, MD 20817 USA. RI Spano, Mark/B-6883-2011 NR 18 TC 23 Z9 23 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 26 PY 1998 VL 80 IS 4 BP 700 EP 703 DI 10.1103/PhysRevLett.80.700 PG 4 WC Physics, Multidisciplinary SC Physics GA YU437 UT WOS:000071717100014 ER PT J AU Gavrishchaka, VV Ganguli, SB Ganguli, GI AF Gavrishchaka, VV Ganguli, SB Ganguli, GI TI Origin of low-frequency oscillations in the ionosphere SO PHYSICAL REVIEW LETTERS LA English DT Article ID TRANSVERSE ION-ACCELERATION; ACOUSTIC SOLITARY WAVES; POLAR CUSP; TOPSIDE IONOSPHERE; MAGNETIZED PLASMA; CYCLOTRON WAVES; VELOCITY SHEAR; ALFVEN WAVES; FIELD LINES; REGION AB The threshold current for the ion-acoustic branch is shown to be significantly lower than the ion-cyclotron branch and insensitive to the ion/electron temperature ratio if there is a transverse gradient in the relative magnetic field aligned drift, V-d, and \(k(y)/k(z))(1/Omega(i))(dV(d)/dx)\ is sufficiently large. The effect persists even when \dV(d)/dx\ --> 0 provided (k(z)/k(y)) --> 0, where k(z) and k(y) are wave vectors along and across the magnetic field and Omega(i) is the ion gyrofrequency. Therefore, the ion-acoustic branch is more central to the plasma processes in the ionosphere than is currently believed. [S0031-9007(97)05043-6]. C1 Sci Applicat Int Corp, Mclean, VA 22102 USA. USN, Res Lab, Div Plasma Phys, Washington, DC 20375 USA. RP Gavrishchaka, VV (reprint author), Sci Applicat Int Corp, Mclean, VA 22102 USA. NR 37 TC 77 Z9 78 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 26 PY 1998 VL 80 IS 4 BP 728 EP 731 DI 10.1103/PhysRevLett.80.728 PG 4 WC Physics, Multidisciplinary SC Physics GA YU437 UT WOS:000071717100021 ER PT J AU Hirth, JP Spanos, G Hall, MG Aaronson, HI AF Hirth, JP Spanos, G Hall, MG Aaronson, HI TI Mechanisms for the development of tent-shaped and invariant-plane-strain-type surface reliefs for plates formed during diffusional phase transformations SO ACTA MATERIALIA LA English DT Article ID PROEUTECTOID ALPHA-PLATES; FCC-BCC BOUNDARIES; FE-C ALLOYS; EPITAXIAL MULTILAYERS; FERRITE PLATES; DISLOCATIONS; DEFECTS; DISCONNECTIONS; NUCLEATION; KINETICS AB Tent-shaped and invariant-plane-strain type surface reliefs are considered for f.c.c. --> h.c.p., --> b.c.c. --> b.c.c. and b.c.c. --> h.c.p. diffusional phase transformations that produce plate-shaped products. Mechanisms of growth by means of mobile structural ledges with disconnection character are described. Different mechanisms are proposed to account for the two types of surface relief in cases where the transformation product is a single crystal. The predicted relief shapes and relief angles are in good agreement with experimental observations. C1 Washington State Univ, Dept Mech & Mat Engn, Pullman, WA 99164 USA. USN, Res Lab, Phys Met Branch, Washington, DC 20375 USA. Univ Birmingham, Sch Met & Mat, Birmingham B15 2TT, W Midlands, England. Carnegie Mellon Univ, Dept Mat Sci & Engn, Pittsburgh, PA 15213 USA. RP Hirth, JP (reprint author), Washington State Univ, Dept Mech & Mat Engn, Pullman, WA 99164 USA. NR 80 TC 34 Z9 34 U1 2 U2 6 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6454 J9 ACTA MATER JI Acta Mater. PD JAN 23 PY 1998 VL 46 IS 3 BP 857 EP 868 DI 10.1016/S1359-6454(97)00302-9 PG 12 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA YW752 UT WOS:000071969800014 ER PT J AU Ofman, L Klimchuk, JA Davila, JM AF Ofman, L Klimchuk, JA Davila, JM TI A self-consistent model for the resonant heating of coronal loops: The effects of coupling with the chromosphere SO ASTROPHYSICAL JOURNAL LA English DT Article DE MHD; Sun, chromosphere; Sun, corona; Sun, magnetic fields; waves ID ALFVEN WAVES; SCALING LAWS; RESISTIVE MHD; ACTIVE-REGION; SOLAR CORONA; GLOBAL MODE; ABSORPTION; DRIVEN; EFFICIENCY; LINES AB We present the first model of resonant heating of coronal loops that incorporates the dependence of the loop density on the heating rate. By adopting the quasi-static equilibrium scaling law rho proportional to Q(5/7), where rho is the density and Q is the volumetric heating rate, we are able to approximate the well-known phenomena of chromospheric evaporation and chromospheric condensation, which regulate the coronal density. We combine this scaling law with a quasi-nonlinear MHD model for the resonant absorption of Alfven waves in order to study the spatial and temporal dependence of the heating. We find that the heating is concentrated in multiple resonance layers, rather than in the single layer of previous models, and that these layers drift throughout the loop to heat the entire volume. These newfound properties are in much better agreement with coronal observations. C1 Hughes STX, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. USN, Res Lab, EO Hulburt Ctr Space Res, Washington, DC 20375 USA. RP Ofman, L (reprint author), Hughes STX, Code 682, Greenbelt, MD 20771 USA. RI Klimchuk, James/D-1041-2012 OI Klimchuk, James/0000-0003-2255-0305 NR 37 TC 64 Z9 64 U1 0 U2 2 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 JAN 20 PY 1998 VL 493 IS 1 BP 474 EP 479 DI 10.1086/305109 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA YV314 UT WOS:000071810800042 ER PT J AU McCarthy, J AF McCarthy, J TI We can do a lot to reduce turbulence accidents SO AVIATION WEEK & SPACE TECHNOLOGY LA English DT Editorial Material C1 USN, Res Lab, Monterey, CA 93940 USA. RP McCarthy, J (reprint author), USN, Res Lab, Monterey, CA 93940 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 19 PY 1998 VL 148 IS 3 BP 70 EP 70 PG 1 WC Engineering, Aerospace SC Engineering GA YT175 UT WOS:000071572900040 ER PT J AU Blanche, W AF Blanche, W TI Refining a food-drug interaction program SO AMERICAN JOURNAL OF HEALTH-SYSTEM PHARMACY LA English DT Editorial Material C1 USN Hosp, Dept Pharm, Jacksonville, FL 32214 USA. RP Blanche, W (reprint author), USN Hosp, Dept Pharm, 2080 Child St, Jacksonville, FL 32214 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 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 JAN 15 PY 1998 VL 55 IS 2 BP 122 EP 123 PG 2 WC Pharmacology & Pharmacy SC Pharmacology & Pharmacy GA YV742 UT WOS:000071858200008 ER PT J AU O'Leary, SK Foutz, BE Shur, MS Bhapkar, UV Eastman, LF AF O'Leary, SK Foutz, BE Shur, MS Bhapkar, UV Eastman, LF TI Electron transport in wurtzite indium nitride SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID MONTE-CARLO CALCULATION; HIGH-FIELD TRANSPORT; GALLIUM NITRIDE; BAND-GAP; VELOCITY; SEMICONDUCTORS; MOBILITY; GAAS; INN AB We present the velocity-field characteristics of wurtzite indium nitride, determined using an ensemble Monte Carlo approach. It is found that indium nitride exhibits an extremely high peak drift velocity at room temperature, 4.3 X 10(7) cm/s, at a doping concentration of 1.0 X 10(17) cm(-3). We also demonstrate that the saturation drift velocity of indium nitride, 2.5 X 10(7) cm/s, is comparable to that of gallium nitride, and much larger than that of gallium arsenide. Our results suggest that the transport characteristics of indium nitride are superior to those of gallium nitride and gallium arsenide, over a wide range of temperatures, from 150 to 500 K, and doping concentrations, up to 1.0 X 10(19) cm(-3). Hence, indium nitride has considerable potential for device applications. (C) 1998 American Institute of Physics. [S0021-8979(98)02202-6]. C1 Rensselaer Polytech Inst, Dept Elect Comp & Syst Engn, Troy, NY 12180 USA. Cornell Univ, Sch Elect Engn, Ithaca, NY 14853 USA. USN, Ctr Surface Warfare, Dahlgren, VA 22448 USA. RP O'Leary, SK (reprint author), Rensselaer Polytech Inst, Dept Elect Comp & Syst Engn, Troy, NY 12180 USA. NR 25 TC 251 Z9 255 U1 3 U2 13 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 JAN 15 PY 1998 VL 83 IS 2 BP 826 EP 829 DI 10.1063/1.366641 PG 4 WC Physics, Applied SC Physics GA YR575 UT WOS:000071509000030 ER PT J AU Craig, AP Bullister, JL Harrison, DE Chervin, RM Semtner, AJ AF Craig, AP Bullister, JL Harrison, DE Chervin, RM Semtner, AJ TI A comparison of temperature, salinity, and chlorofluorocarbon observations with results from a 1 degrees resolution three-dimensional global ocean model SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID GENERAL-CIRCULATION MODELS; SCALE WATER MASSES; WORLD OCEAN; CLIMATE MODEL; CHLOROFLUOROMETHANES; DISTRIBUTIONS; ATLANTIC; SIMULATIONS; RADIOCARBON; FIELDS AB We describe the ability of a moderate-resolution global ocean model to simulate the general circulation and the ocean-atmosphere exchange and redistribution of chlorofluorocarbons (CFCs). The model was spun up from climatological initial conditions and has been integrated for decades representing 1930 to the present. Climatological monthly mean winds were imposed during the spin-up and first 50 years of the integration, From 1980, monthly mean European Centre for Medium-Range Weather Forecasts (ECMWF) wind stress fields were used. We compare model results to cruise data and to long-term mean observations and find good qualitative agreement in most areas. Overall, the model agrees reasonably well in regions where measurable CFCs have. been observed, and the large-scale model ventilation pathways appear realistic. One of the most conspicuous shortcomings is the small volume of Antarctic Intermediate Water in the model results. This leads to errors in the general water mass structure and in CFC concentrations in the model in other regions. Notable CFC differences are found in regions where deep water masses are formed and in the upper subtropical gyre regions in which the Kuroshio extension exists. The model oceanic CFC sink represents <1% of all CFCs produced since 1930 and is small relative to the stratospheric sink for these compounds. C1 Natl Ctr Atmospher Res, Boulder, CO 80307 USA. NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. USN, Postgrad Sch, Monterey, CA 93943 USA. RP Natl Ctr Atmospher Res, Pob 3000, Boulder, CO 80307 USA. EM harrison@pmel.noaa.gov RI Harrison, Don/D-9582-2013 NR 43 TC 14 Z9 18 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9275 EI 2169-9291 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD JAN 15 PY 1998 VL 103 IS C1 BP 1099 EP 1119 DI 10.1029/97JC02394 PG 21 WC Oceanography SC Oceanography GA YQ713 UT WOS:000071415800007 ER PT J AU Lin, HB Tonucci, RJ Campillo, AJ AF Lin, HB Tonucci, RJ Campillo, AJ TI Two-dimensional photonic bandgap optical limiter in the visible SO OPTICS LETTERS LA English DT Article AB Operation of a two-dimensional photonic bandgap optical limiter was studied at 514.5 nm for pulse durations of 0.1 to 4 ms. Photonic crystals consisted of 180-230-nm spatial-period nanochannel glasses containing a thermal nonlinear liquid. A dynamic range in excess of 130 was observed in a single-element device. C1 USN, Res Lab, Washington, DC 20375 USA. RP Lin, HB (reprint author), USN, Res Lab, Code 5610, Washington, DC 20375 USA. NR 12 TC 54 Z9 57 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 JAN 15 PY 1998 VL 23 IS 2 BP 94 EP 96 DI 10.1364/OL.23.000094 PG 3 WC Optics SC Optics GA YQ966 UT WOS:000071443100005 PM 18084423 ER PT J AU Putnam, MA Dennis, ML Duling, IN Askins, CG Friebele, EJ AF Putnam, MA Dennis, ML Duling, IN Askins, CG Friebele, EJ TI Broadband square-pulse operation of a passively mode-locked fiber laser for fiber Bragg grating interrogation SO OPTICS LETTERS LA English DT Article ID ARRAYS; INSTRUMENTATION AB A long-cavity, passively mode-locked erbium fiber laser operated in the square-pulse regime is demonstrated as a useful light source for interrogating fiber Bragg grating arrays. Output pulses with 4-W peak-power, 10-ns pulse widths, and bandwidths greater than 60 nm were used successfully to interrogate 2% fiber Bragg gratings. C1 USN, Res Lab, Div Opt Sci, Washington, DC 20375 USA. RP Putnam, MA (reprint author), USN, Res Lab, Div Opt Sci, Washington, DC 20375 USA. NR 14 TC 47 Z9 49 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 JAN 15 PY 1998 VL 23 IS 2 BP 138 EP 140 DI 10.1364/OL.23.000138 PG 3 WC Optics SC Optics GA YQ966 UT WOS:000071443100020 PM 18084438 ER PT J AU Gunnarsson, O Erwin, SC Koch, E Martin, RM AF Gunnarsson, O Erwin, SC Koch, E Martin, RM TI Role of alkali atoms in A(4)C(60) SO PHYSICAL REVIEW B LA English DT Article ID ELECTRON-VIBRON INTERACTIONS; CHARGED FULLERENES; DOPED C-60; METAL; SUPERCONDUCTIVITY; 1ST-PRINCIPLES; FULLERIDES; RB4C60; C60; C70 AB We show that hopping via alkali atoms plays an important role for the t(1u) band of A(4)C(60) (A = K, Rb), in strong contrast to A(3)C(60) Thus the t(1u) band is broadened by more than 40% by the presence of the alkali atoms. The difference between A(4)C(60) and A(3)C(60) is in particular due to the less symmetric location of the alkali atoms in A(4)C(60). We present tight-binding and ab initio band-structure calculations to support our conclusions. C1 Max Planck Inst Festkorperforsch, D-70506 Stuttgart, Germany. USN, Res Lab, Complex Syst Theory Branch, Washington, DC 20375 USA. Univ Illinois, Dept Phys, Urbana, IL 61801 USA. RP Gunnarsson, O (reprint author), Max Planck Inst Festkorperforsch, D-70506 Stuttgart, Germany. RI Erwin, Steven/B-1850-2009 NR 23 TC 24 Z9 24 U1 0 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 JAN 15 PY 1998 VL 57 IS 4 BP 2159 EP 2162 DI 10.1103/PhysRevB.57.2159 PG 4 WC Physics, Condensed Matter SC Physics GA YV536 UT WOS:000071834900031 ER PT J AU Yang, SH Mehl, MJ Papaconstantopoulos, DA AF Yang, SH Mehl, MJ Papaconstantopoulos, DA TI Application of a tight-binding total-energy method for Al, Ga, and In SO PHYSICAL REVIEW B LA English DT Article ID NOBLE-METALS; TRANSITION; GALLIUM; PRESSURE; ELEMENTS; ALUMINUM; CRYSTAL; INDIUM AB We apply our tight-binding (TB) methodology to the sp metals Al, Ga, and In, all of which have distinctive ground states. The results show that this approach works as well for such elements as it does for transition metals. Bulk properties such as lattice constants, bulk moduli, and elastic constants were found to be consistent with experiments. We emphasize that our method successfully predicts the correct ground states of both Ga and In, without inclusion of the corresponding first-principles data in the fit. In addition, we note the success of our method in Al, a metal not normally described by TB. C1 USN, Complex Syst Theory Branch, Res Lab, Washington, DC 20375 USA. RP Yang, SH (reprint author), USN, Complex Syst Theory Branch, Res Lab, Washington, DC 20375 USA. RI Mehl, Michael/H-8814-2016 NR 27 TC 22 Z9 23 U1 1 U2 5 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JAN 15 PY 1998 VL 57 IS 4 BP R2013 EP R2016 DI 10.1103/PhysRevB.57.R2013 PG 4 WC Physics, Condensed Matter SC Physics GA YV536 UT WOS:000071834900004 ER PT J AU Stellman, CM Bucholtz, F Ewing, KJ Aggarwal, ID AF Stellman, CM Bucholtz, F Ewing, KJ Aggarwal, ID TI A fiber-optic pipette for rapid long-pathlength capillary spectroscopy SO SENSORS AND ACTUATORS B-CHEMICAL LA English DT Article DE fiber-optic pipette; spectroscopy; Raman spectra AB A fiber-optic pipette (FOP) has been developed. The device uniquely couples a glass capillary, a commun syringe and a single optical fiber to provide for a facile means of achieving long-pathlength capillary spectroscopy. The novel mechanical configuration uf the FOP allows for the acquisition of rapid spectroscopic measurements of small-volume liquid samples while simultaneously achieving signal enhancements of the collected spectroscopic signal. The device has been successful employed in collective the Raman spectra of several solvents, a preliminary characterization of the signal enhancement capabilities has been demonstrated and the advantages associated with the device have been discussed. (C) 1998 Published by Elsevier Science S.A. All rights reserved. C1 USN, Res Lab, Div Opt Sci, Washington, DC 20375 USA. RP Stellman, CM (reprint author), USN, Res Lab, Div Opt Sci, Code 5606,4555 Overlook Ave SW, Washington, DC 20375 USA. NR 6 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-4005 J9 SENSOR ACTUAT B-CHEM JI Sens. Actuator B-Chem. PD JAN 15 PY 1998 VL 46 IS 1 BP 56 EP 60 DI 10.1016/S0925-4005(97)00329-8 PG 5 WC Chemistry, Analytical; Electrochemistry; Instruments & Instrumentation SC Chemistry; Electrochemistry; Instruments & Instrumentation GA ZJ334 UT WOS:000073203600009 ER PT J AU Smith, MP George, C Kozikowski, AP AF Smith, MP George, C Kozikowski, AP TI The synthesis of tricyclic cocaine analogs via the 1,3-dipolar cycloaddition of oxidopyridinium betaines. SO TETRAHEDRON LETTERS LA English DT Article ID DOPAMINE TRANSPORTER; BINDING; RECEPTOR; NITROGEN; ESTERS AB Tricyclic cocaine analogs with a spatially fixed nitrogen lone pair were synthesized as structural probes of the dopamine transporter. A tandem cycloaddition/radical cyclization protocol was used to gain access to analog 12 with a two carbon linker between C-2 and N-8. On the other hand, the intramolecular dipolar cycloaddition reaction of betaine 13 was used to procure cocaine analog 18 and its C-3 epimer 19 in which an extra ring links N-8 to C-6. Binding studies reveal 12c and 18 to be potent DAT ligands. (C) 1997 Elsevier Science Ltd. All rights reserved. C1 Georgetown Univ, Med Ctr, Drug Discovery Program, Inst Cognit & Comp Sci, Washington, DC 20007 USA. USN, Res Lab, Struct Matter Lab, Washington, DC 20375 USA. RP Kozikowski, AP (reprint author), Georgetown Univ, Med Ctr, Drug Discovery Program, Inst Cognit & Comp Sci, 3970 Reservior Rd NW, Washington, DC 20007 USA. NR 19 TC 19 Z9 19 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0040-4039 J9 TETRAHEDRON LETT JI Tetrahedron Lett. PD JAN 15 PY 1998 VL 39 IS 3-4 BP 197 EP 200 DI 10.1016/S0040-4039(97)10524-X PG 4 WC Chemistry, Organic SC Chemistry GA YP098 UT WOS:000071241000008 ER PT J AU Fatemi, M Thompson, PE Twigg, ME Chaudhuri, J AF Fatemi, M Thompson, PE Twigg, ME Chaudhuri, J TI The effect of post-growth cooling rate on the defect structure in MBE-grown buried layers of Si1-xGex on Si substrates SO THIN SOLID FILMS LA English DT Article DE cool-down; cooling rate; temperatures ID MOLECULAR-BEAM EPITAXY; STRAIN; STRESS AB The effect of cooling rate on the defect structure in Si(1-x)G(x), layers grown on Si (100) substrates has been studied. SiGe layers 200 nm thick. with germanium fractions between 0.09 and 0.14 and capped with a 50-nm layer of Si, were grown by molecular beam epitaxy at temperatures of 550, 710 and 800 degrees C. The defect structure in the layers was studied by means of high resolution double crystal X-ray diffractometry and transmission electron microscopy for two different modes of cool-down. In the 'fast' mode, the heat source was turned off abruptly, while in the 'slow' mode the power was lowered ill small steps equal to about 2% of the initial power, The system was then allowed to reach equilibrium before the power was lowered again. X-ray rocking curves showed significant broadening after rapid cool-down from higher temperatures, whereas the corresponding strains decreased only slightly and independently of the rate of cool-down. In ol der to explain these results, a model is proposed in which the buried layer is distorted into small, slightly misoriented regions by rapid cooling, Thus, the original strain remains unchanged within the small regions and the X-ray profile is broadened primarily by crystalline distortion and without a significant contribution from dislocations. The distortion can lend to fracture for rapid cool-down from sufficiently high temperatures, e.g., 800 degrees C. The model is consistent with both transmission electron microscopy and calculations of stress due to non-uniform cooling. Published by Elsevier Science S.A. C1 USN, Res Lab, Div Elect Sci & Technol, Washington, DC 20375 USA. Wichita State Univ, Dept Mech Engn, Wichita, KS 67208 USA. RP Fatemi, M (reprint author), USN, Res Lab, Div Elect Sci & Technol, Washington, DC 20375 USA. RI Chaudhuri, Jharna/E-8863-2013 NR 20 TC 0 Z9 0 U1 1 U2 3 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD JAN 14 PY 1998 VL 312 IS 1-2 BP 362 EP 371 DI 10.1016/S0040-6090(97)00737-2 PG 10 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA ZN334 UT WOS:000073635500061 ER PT J AU Deisz, JJ Hess, DW Serene, JW AF Deisz, JJ Hess, DW Serene, JW TI Coupled electrons and pair fluctuations in two dimensions: A transition to superconductivity in a conserving approximation SO PHYSICAL REVIEW LETTERS LA English DT Article ID U HUBBARD-MODEL; COHERENCE LENGTH SUPERCONDUCTORS; SUPERFLUID DENSITY; SYSTEMS AB We report a superconducting transition in the fully conserving fluctuation exchange approximation for a two-dimensional attractive Hubbard model. The transition temperature agrees well with quantum Monte Carlo calculations, but the superfluid density and specific heat near T-c have anomalous temperature dependences for lattice sizes up to 64 x 64. C1 Georgetown Univ, Dept Phys, Washington, DC 20057 USA. USN, Complex Syst Theory Branch, Res Lab, Washington, DC 20375 USA. RP Deisz, JJ (reprint author), Black Hills State Univ, Dept Phys Sci & Math, Spearfish, SD 57799 USA. NR 27 TC 20 Z9 20 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 12 PY 1998 VL 80 IS 2 BP 373 EP 376 DI 10.1103/PhysRevLett.80.373 PG 4 WC Physics, Multidisciplinary SC Physics GA YQ975 UT WOS:000071444000042 ER PT J AU Dinsmore, AD Wong, DT Nelson, P Yodh, AG AF Dinsmore, AD Wong, DT Nelson, P Yodh, AG TI Hard spheres in vesicles: Curvature-induced forces and particle-induced curvature SO PHYSICAL REVIEW LETTERS LA English DT Article ID COLLOID-POLYMER MIXTURE; DEPLETION FORCE; MACROMOLECULAR STRUCTURE; PHASE-SEPARATION; FLUID MEMBRANES; BINARY; DETERMINANT; CONFINEMENT; TRANSITIONS; SURFACTANT AB We explore the interplay of membrane curvature and nonspecific binding due to excluded-volume effects among colloidal particles inside lipid bilayer vesicles. We trapped submicron spheres of two different sizes inside a pear-shaped, multilamellar vesicle and found the larger spheres to be pinned to the vesicle's surface and pushed in the direction of increasing curvature. A simple model predicts that hard spheres can induce shape changes in flexible vesicles. The results demonstrate an important relationship between the shape of a vesicle or pore and the arrangement of particles within it. C1 Univ Penn, Dept Phys & Astron, Philadelphia, PA 19104 USA. RP Dinsmore, AD (reprint author), USN, Res Lab, Ctr Biomol Sci & Engn, Washington, DC 20375 USA. EM tdd@cbmse.nrl.navy.mil RI Nelson, Philip/I-6251-2015 OI Nelson, Philip/0000-0002-1782-3076 NR 35 TC 90 Z9 93 U1 2 U2 25 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 12 PY 1998 VL 80 IS 2 BP 409 EP 412 DI 10.1103/PhysRevLett.80.409 PG 4 WC Physics, Multidisciplinary SC Physics GA YQ975 UT WOS:000071444000051 ER PT J AU Schuler, DL Ainsworth, TL Lee, JS De Grandi, G AF Schuler, DL Ainsworth, TL Lee, JS De Grandi, G TI Topographic mapping using polarimetric SAR data SO INTERNATIONAL JOURNAL OF REMOTE SENSING LA English DT Article ID INTERFEROMETRIC SAR; RADAR; SCATTERING; AREAS AB A new remote sensing technique using polarimetric synthetic aperture radar (SAR) data has been developed which can measure terrain slopes in the azimuthal. or along-track, direction. Terrain elevation maps can then be generated by integrating these slopes. The processing of both single-pass, and orthogonal two-pass, datasets is investigated. When single-pass SAR data is used elevation groundtruth must be available for at least one point of each profile formed in the azimuthal direction. When orthogonal two-pass slope data is employed, the elevation surface may be generated as an iterative solution of the Poisson equation and only a single elevation tie-point is required. The results of two studies are presented. In the first study slopes have been measured using single-pass P-band data for a forested area in northern California. The elevation surface generated with this data has been compared with a Digital Elevation Model (DEM) produced by a C-band interferometric SAR. The second study uses orthogonal two-pass P-band data as a test of the Poisson equation approach for an area in Death Valley National Park, California. The orthogonal two-pass results have been compared with a co-registered, conventional, U.S. Geological Survey (USGS) product. Technique accuracy and potential applications are discussed. C1 USN, Res Lab, Remote Sensing Div, Washington, DC 20375 USA. Commiss European Communities, Joint Res Ctr, Space Applicat Inst, I-21020 Ispra, VA, Italy. RP Schuler, DL (reprint author), USN, Res Lab, Remote Sensing Div, Washington, DC 20375 USA. NR 18 TC 29 Z9 32 U1 0 U2 6 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 JAN 10 PY 1998 VL 19 IS 1 BP 141 EP 160 DI 10.1080/014311698216477 PG 20 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA YT715 UT WOS:000071635700010 ER PT J AU Meredith, C Russell, TP Mowrey, RC McDonald, JR AF Meredith, C Russell, TP Mowrey, RC McDonald, JR TI Decomposition of 5-nitro-2,4-dihydro-3H-1,2,4-triazol-3-one (NTO): Energetics associated with several proposed initiation routes SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID HARTREE-FOCK THEORY; THERMAL-DECOMPOSITION; 3-NITRO-1,2,4-TRIAZOL-5-ONE NTO; MECHANISM; DERIVATIVES; ENERGIES; MOLECULE AB Initial steps for several proposed decomposition mechanisms of NTO have been studied theoretically in order to determine the energies of various reaction intermediates. The methods applied were restricted Hartree-Fock self-consistent field (SCF), single-and double-excitation configuration interaction (CISD), CISD corrected for unlinked quadruple excitations (CISD+Q), and coupled cluster including all single and double substitutions (CCSD) with a double-xi plus polarization (DZP) basis set. Harmonic vibrational frequencies were computed to characterize the species at the stationary points. The previously reported mechanisms examined include decomposition initiated by C-NO2 homolysis, migration of ring substituents, and ring-opening processes. On the basis of the energetics of the various schemes, our computations suggest that C-NO2 bond homolysis is the most probable initial step for unimolecular decomposition of NTO. C1 USN, Res Lab, Div Chem, Washington, DC 20375 USA. RP McDonald, JR (reprint author), USN, Res Lab, Div Chem, Code 6110, Washington, DC 20375 USA. NR 36 TC 32 Z9 32 U1 1 U2 4 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 JAN 8 PY 1998 VL 102 IS 2 BP 471 EP 477 DI 10.1021/jp972602j PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA YR894 UT WOS:000071542200019 ER PT J AU Moriarty, RM Tao, AP Gilardi, R Song, ZZ Tuladhar, SM AF Moriarty, RM Tao, AP Gilardi, R Song, ZZ Tuladhar, SM TI An oligooxamacrocycle containing a pi-donor tetrathiafulvalene and a pi-acceptor quinone. Molecular and supramolecular structure SO CHEMICAL COMMUNICATIONS LA English DT Article ID ELECTRON-DONOR; INTRAMOLECULAR QUINHYDRONES; METAL-COMPLEXES; SERIES AB Tetrathiafulvalenedicarbonyl chloride reacts with 2,5-bis[(2-hydroxyethoxy)ethyl]-1,4-benzoquinone to afford a novel charge-transfer oligooxamacrocycle whose molecular and supramolecular structure are reported. C1 Univ Illinois, Dept Chem, Chicago, IL 60608 USA. USN, Res Lab, Washington, DC 20375 USA. RP Moriarty, RM (reprint author), Univ Illinois, Dept Chem, Chicago, IL 60608 USA. NR 16 TC 15 Z9 15 U1 0 U2 1 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON ROAD, CAMBRIDGE CB4 4WF, CAMBS, ENGLAND SN 1359-7345 J9 CHEM COMMUN JI Chem. Commun. PD JAN 7 PY 1998 IS 1 BP 157 EP 158 DI 10.1039/a705917e PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA YT355 UT WOS:000071593500076 ER PT J AU DeWilde, Y Miyakawa, N Guptasarma, P Iavarone, M Ozyuzer, L Zasadzinski, JF Romano, P Hinks, DG Kendziora, C Crabtree, GW Gray, KE AF DeWilde, Y Miyakawa, N Guptasarma, P Iavarone, M Ozyuzer, L Zasadzinski, JF Romano, P Hinks, DG Kendziora, C Crabtree, GW Gray, KE TI Unusual strong-coupling effects in the tunneling spectroscopy of optimally doped and overdoped Bi2Sr2CaCu2O8+delta SO PHYSICAL REVIEW LETTERS LA English DT Article ID ANGLE-RESOLVED PHOTOEMISSION; STATES; SUPERCONDUCTORS; DENSITY; ANISOTROPY; GAP AB Tunneling spectroscopy measurements are reported on single crystals of Bi2Sr2CaCu2O8+delta using vacuum tunneling and point-contact methods. A reproducible dip feature in the tunneling conductance is found near /eV/ = 2 Delta, observed for both voltage polarities in the best resolved spectra. With overdoping the position of the dip continues to scale with a, and its magnitude decreases as a decreases. These results indicate that the dip feature arises from a strong-coupling effect whereby the quasiparticle lifetime is decreased at a characteristic energy of similar to 2 Delta, consistent with an electron-electron pairing interaction. C1 Argonne Natl Lab, Sci & Technol Ctr Supercond, Argonne, IL 60439 USA. Sci Univ Tokyo, Dept Appl Phys, Shinjuku Ku, Tokyo 162, Japan. IIT, Chicago, IL 60616 USA. USN, Res Lab, Washington, DC 20375 USA. RP DeWilde, Y (reprint author), Argonne Natl Lab, Sci & Technol Ctr Supercond, Argonne, IL 60439 USA. RI Iavarone, Maria/C-3628-2008; Ozyuzer, Lutfi/H-3142-2011; OI De Wilde, Yannick/0000-0002-5973-1460 NR 23 TC 166 Z9 167 U1 1 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 5 PY 1998 VL 80 IS 1 BP 153 EP 156 DI 10.1103/PhysRevLett.80.153 PG 4 WC Physics, Multidisciplinary SC Physics GA YQ289 UT WOS:000071370400039 ER PT B AU Syverson, P AF Syverson, P GP IEEE TI Weakly secret bit commitment: Applications to lotteries and fair exchange SO 11TH IEEE COMPUTER SECURITY FOUNDATIONS WORKSHOP - PROCEEDINGS LA English DT Proceedings Paper CT 11th IEEE Computer Security Foundations Workshop CY JUN 09-11, 1998 CL ROCKPORT, MA SP IEEE AB This paper presents applications for the weak protection of secrets in which weakness is not just acceptable but desirable. For one application, two versions of a lottery scheme are presented in which the result of the lottery is determined by the ticket numbers purchased, but no one can control the outcome or determine what it is until after the lottery closes. This is because the outcome is kept secret in a way that is breakable after a predictable amount of time and/or computation. Another. presented application is a variant on fair,exchange protocols that requires no trusted third party at all. C1 USN, Res Lab, Ctr High Assurance Comp Syst, Washington, DC 20375 USA. RP Syverson, P (reprint author), USN, Res Lab, Ctr High Assurance Comp Syst, Washington, DC 20375 USA. NR 0 TC 27 Z9 31 U1 2 U2 2 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA BN 0-8186-8489-5 PY 1998 BP 2 EP 13 DI 10.1109/CSFW.1998.683149 PG 12 WC Computer Science, Theory & Methods SC Computer Science GA BL15B UT WOS:000074492800001 ER PT B AU Volpano, D Smith, G AF Volpano, D Smith, G GP IEEE TI Probabilistic noninterference in a concurrent language SO 11TH IEEE COMPUTER SECURITY FOUNDATIONS WORKSHOP - PROCEEDINGS LA English DT Proceedings Paper CT 11th IEEE Computer Security Foundations Workshop CY JUN 09-11, 1998 CL ROCKPORT, MA SP IEEE AB In [15], we give a type system that guarantees that well-typed multi-threaded programs are possibilistically noninterfering. If thread scheduling is probabilistic, however, then well-typed programs may have probabilistic timing channels. We describe how they can be eliminated without making the type system more restrictive. We shaw that well-typed concurrent programs are probabilistically noninterfering if every total command with a high guard executes atomically. The proof uses the concept of a probabilistic state of a computation, following the work of Kozen [10].(1). C1 USN, Postgrad Sch, Dept Comp Sci, Monterey, CA 93943 USA. RP Volpano, D (reprint author), USN, Postgrad Sch, Dept Comp Sci, Monterey, CA 93943 USA. NR 0 TC 26 Z9 27 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 0-8186-8489-5 PY 1998 BP 34 EP 43 DI 10.1109/CSFW.1998.683153 PG 10 WC Computer Science, Theory & Methods SC Computer Science GA BL15B UT WOS:000074492800004 ER PT B AU Rohaly, GD Langland, RH Gelaro, R AF Rohaly, GD Langland, RH Gelaro, R GP AMS AMS TI Identifying regions where the forecast of tropical cyclone tracks is most sensitive to initial condition uncertainty using adjoint methods 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 USN, Res Lab, Monterey, CA 93943 USA. RP Rohaly, GD (reprint author), USN, Res Lab, Monterey, CA 93943 USA. NR 0 TC 3 Z9 3 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 1998 BP 337 EP 340 PG 4 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BM02Q UT WOS:000077436900106 ER PT B AU Ritchie, EA Harr, PA Elsberry, RL AF Ritchie, EA Harr, PA Elsberry, RL GP AMS AMS TI A study of the development of mesoscale asymmetries in tropical cyclone structure during landfall 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 USN, Postgrad Sch, Dept Meteorol, Monterey, CA 93943 USA. RP Ritchie, EA (reprint author), USN, Postgrad Sch, Dept Meteorol, Monterey, CA 93943 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 345 EP 348 PG 4 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BM02Q UT WOS:000077436900108 ER PT B AU Kang, MH Froscher, JN Eppinger, BJ AF Kang, MH Froscher, JN Eppinger, BJ GP IEEE IEEE TI Towards an infrastructure for MLS distributed computing SO 14TH ANNUAL COMPUTER SECURITY APPLICATIONS CONFERENCE, PROCEEDINGS LA English DT Proceedings Paper CT 14th Annual Computer Security Applications Conference CY DEC 07-11, 1998 CL PHOENIX, AZ SP Appl Comp Security Associates, ACM Special Interest Grp Security Audit & Control AB Distributed computing owes its success to the development of infrastructure, middleware, and standards (e.g., CORBA) to support interoperability. The computing community has slowly recognized the need to protect information and has begun to develop commercial security infrastructures and standards. The US Government must protect national security information against unauthorized information flow. To support MLS distributed computing, a MLS infrastructure must be built that enables information sharing among users at different classification levels. This infrastructure should provide MLS services for protection of classified information and use both the emerging distributed computing and commercial security infrastructures, when possible. The resulting infrastructure will enable users to integrate commercial information technology products into their systems. In this paper, we examine the philosophy that has led to successful distributed computing among heterogeneous, autonomous components and propose an analogous approach for MLS distributed computing. We identify some services that are required to support MLS distributed computing, argue that these services are needed regardless of the MLS architecture used, present an approach for designing these services, and provide design guidance for a critical building block of the MLS infrastructure. C1 USN, Res Lab, Div Informat Technol, Washington, DC 20375 USA. RP Kang, MH (reprint author), USN, Res Lab, Div Informat Technol, Washington, DC 20375 USA. NR 6 TC 2 Z9 2 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 0-8186-8789-4 PY 1998 BP 91 EP 100 DI 10.1109/CSAC.1998.738587 PG 10 WC Computer Science, Hardware & Architecture; Computer Science, Information Systems; Computer Science, Theory & Methods SC Computer Science GA BM28R UT WOS:000078270300009 ER PT B AU Wright, R Shifflett, DJ Irvine, CE AF Wright, R Shifflett, DJ Irvine, CE GP IEEE IEEE TI Security architecture for a virtual heterogeneous machine SO 14TH ANNUAL COMPUTER SECURITY APPLICATIONS CONFERENCE, PROCEEDINGS LA English DT Proceedings Paper CT 14th Annual Computer Security Applications Conference CY DEC 07-11, 1998 CL PHOENIX, AZ SP Appl Comp Security Associates, ACM Special Interest Grp Security Audit & Control AB We describe security for a virtual heterogeneous machine (VHM). Our security architecture is based upon separation of services into four distinct domains. It is designed to take advantage of operating system support for domains, where available. We have chosen to use emerging public key technology as art interim solution to provide domain separation. A prototype demonstration of our architecture has been developed. C1 USN, Postgrad Sch, Dept Comp Sci, Monterey, CA 93943 USA. RP Wright, R (reprint author), USN, Postgrad Sch, Dept Comp Sci, Monterey, CA 93943 USA. EM rewright@nps.navy.mil; dshifflett@gwdi.com; irvine@cs.nps.navy.mil NR 20 TC 2 Z9 2 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 0-8186-8789-4 PY 1998 BP 167 EP 177 DI 10.1109/CSAC.1998.738611 PG 11 WC Computer Science, Hardware & Architecture; Computer Science, Information Systems; Computer Science, Theory & Methods SC Computer Science GA BM28R UT WOS:000078270300017 ER PT B AU Hadjimichael, M Tag, PM Bankert, RL AF Hadjimichael, M Tag, PM Bankert, RL GP AMS AMS TI Discovering model bias in the determination of cloud base height SO 14TH CONFERENCE ON PROBABILITY AND STATISTICS IN THE ATMOSPHERIC SCIENCES LA English DT Proceedings Paper CT 14th Conference on Probability and Statistics in the Atmospheric Sciences CY JAN 11-16, 1998 CL PHOENIX, AZ SP Amer Meteorol Soc (AMS) C1 USN, Res Lab, Monterey, CA 93943 USA. RP Hadjimichael, M (reprint author), USN, Res Lab, 7 Grace Hopper Ave, Monterey, CA 93943 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 J77 EP J80 PG 4 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BM02N UT WOS:000077436200055 ER PT B AU Lee, TF Hawkins, J Nagle, R Richardson, R Turk, J AF Lee, TF Hawkins, J Nagle, R Richardson, R Turk, J GP AMER METEOROL SOC AMER METEOROL SOC TI Preview of R & D satellite applications by Internet SO 14TH INTERNATIONAL CONFERENCE ON INTERACTIVE INFORMATION AND PROCESSING SYSTEM (IIPS) FOR METEOROLOGY, OCEANOGRAPHY, AND HYDROLOGY LA English DT Proceedings Paper CT 14th International Conference on Interactive Information and Processing Systems for Meteorology, Oceanography, and Hydrology at 78th AMS Annual Meeting CY JAN 11-16, 1998 CL PHOENIX, AZ SP Amer Meteorol Soc C1 USN, Res Lab, Marine Meteorol Div, Monterey, CA 93943 USA. RP Lee, TF (reprint author), USN, Res Lab, Marine Meteorol Div, 7 Grace Hopper Ave, Monterey, CA 93943 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 103 EP 107 PG 5 WC Computer Science, Information Systems; Meteorology & Atmospheric Sciences SC Computer Science; Meteorology & Atmospheric Sciences GA BL80G UT WOS:000076779900028 ER PT B AU Nuss, WA AF Nuss, WA GP AMER METEOROL SOC AMER METEOROL SOC TI The real-time environmental information network and analysis system (REINAS): A scalable, mesoscale observing and data management system. SO 14TH INTERNATIONAL CONFERENCE ON INTERACTIVE INFORMATION AND PROCESSING SYSTEM (IIPS) FOR METEOROLOGY, OCEANOGRAPHY, AND HYDROLOGY LA English DT Proceedings Paper CT 14th International Conference on Interactive Information and Processing Systems for Meteorology, Oceanography, and Hydrology at 78th AMS Annual Meeting CY JAN 11-16, 1998 CL PHOENIX, AZ SP Amer Meteorol Soc C1 USN, Postgrad Sch, Dept Meteorol, Code MR Nu, Monterey, CA 93943 USA. RP Nuss, WA (reprint author), USN, Postgrad Sch, Dept Meteorol, Code MR Nu, 589 Dyer Rd,Room 254, Monterey, CA 93943 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 534 EP 538 PG 5 WC Computer Science, Information Systems; Meteorology & Atmospheric Sciences SC Computer Science; Meteorology & Atmospheric Sciences GA BL80G UT WOS:000076779900142 ER PT B AU Harr, PA Elsberry, RL Hogan, TF AF Harr, PA Elsberry, RL Hogan, TF GP AMER METEOROL SOC AMER METEOROL SOC AMER METEOROL SOC TI Mesoscale aspects in tropical cyclone structure changes during landfall and extratropical transition 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 USN, Postgrad Sch, Dept Meteorol, Monterey, CA 93943 USA. RP Harr, PA (reprint author), USN, Postgrad Sch, Dept Meteorol, Monterey, CA 93943 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 16 EP 18 PG 3 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BL92Q UT WOS:000077162300006 ER PT B AU Schwingshakl, KJ Pauley, PM Holt, TR AF Schwingshakl, KJ Pauley, PM Holt, TR GP AMER METEOROL SOC AMER METEOROL SOC AMER METEOROL SOC TI A case study of strong surface winds associated with an upper front using the COAMPS data assimilation 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 USN, Postgrad Sch, Dept Meteorol, Monterey, CA 93943 USA. RP Pauley, PM (reprint author), USN, Postgrad Sch, Dept Meteorol, 589 Dyer Rd Room 254, Monterey, CA 93943 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 92 EP 94 PG 3 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BL92Q UT WOS:000077162300033 ER PT B AU Pauley, PM Stephens, EL AF Pauley, PM Stephens, EL GP AMER METEOROL SOC AMER METEOROL SOC AMER METEOROL SOC TI A comparison of upper front strength as analyzed by NORAPS and as observed by ACARS-equipped aircraft 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 USN, Postgrad Sch, Dept Meteorol, Monterey, CA 93943 USA. RP Pauley, PM (reprint author), USN, Postgrad Sch, Dept Meteorol, 589 Dyer Rd Room 254, Monterey, CA 93943 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 1998 BP 95 EP 97 PG 3 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BL92Q UT WOS:000077162300034 ER PT B AU Holtmeier, LE Smith, DR AF Holtmeier, LE Smith, DR GP AMER METEOROL SOC AMER METEOROL SOC AMER METEOROL SOC TI A comparative study of two winter coastal storms: 12-15 March 1993 and 6-9 January 1996 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 USN Acad, Dept Oceanog, Annapolis, MD 21402 USA. RP Smith, DR (reprint author), USN Acad, Dept Oceanog, 572 Holloway Rd, Annapolis, MD 21402 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 424 EP 427 PG 4 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BL92Q UT WOS:000077162300143 ER PT B AU Doyle, JD Shapiro, MA Bartels, D Gall, R AF Doyle, JD Shapiro, MA Bartels, D Gall, R GP AMER METEOROL SOC AMER METEOROL SOC AMER METEOROL SOC TI The numerical simulation and validation of a breaking gravity wave during FASTEX 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 USN, Res Lab, Monterey, CA 93943 USA. RP Doyle, JD (reprint author), USN, Res Lab, Monterey, CA 93943 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 1998 BP 460 EP 462 PG 3 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BL92Q UT WOS:000077162300155 ER PT B AU Langland, RH Gelaro, R Rohaly, GD AF Langland, RH Gelaro, R Rohaly, GD GP AMER METEOROL SOC AMER METEOROL SOC AMER METEOROL SOC TI Adjoint-based adaptive observations in FASTEX 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 USN, Res Lab, Monterey, CA 93943 USA. RP Langland, RH (reprint author), USN, Res Lab, Monterey, CA 93943 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 513 EP 516 PG 4 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BL92Q UT WOS:000077162300200 ER PT B AU Bodner, SE AF Bodner, SE GP IEEE IEEE IEEE TI Status of direct-drive laser fusion target designs SO 17TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 17th IEEE/NPSS Symposium on Fusion Engineering CY OCT 06-10, 1997 CL SAN DIEGO, CA SP IEEE, NPSS, Boeing Co, Lawrence Livermore Natl Lab, MIT, Sandia Natl Lab, Univ California San Diego, Univ Illinois AB There is now substantial evidence that a direct-drive target driven with a Krypton Fluoride laser can reach ignition. Sufficient laser beam uniformity has been achieved with optical beam smoothing. Laser-plasma instabilities can likely be controlled with a short laser wavelength, with optical beam smoothing, and with the angular overlap of multiple laser beams. The Rayleigh-Taylor instability can be controlled by preheating the ablator. Targets are now being designed that satisfy all of these constraints. They may also have enough energy gain for a fusion reactor. C1 USN, Res Lab, Div Plasma Phys, Washington, DC 20375 USA. RP Bodner, SE (reprint author), USN, Res Lab, Div Plasma Phys, Washington, DC 20375 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 0-7803-4226-7 PY 1998 BP 588 EP 592 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Nuclear Science & Technology; Physics GA BL48U UT WOS:000075681300126 ER PT B AU Sethian, JD Obenschain, SP Lehmberg, RH McGeoch, MW AF Sethian, JD Obenschain, SP Lehmberg, RH McGeoch, MW GP IEEE IEEE IEEE TI KrF lasers for inertial fusion energy SO 17TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 17th IEEE/NPSS Symposium on Fusion Engineering CY OCT 06-10, 1997 CL SAN DIEGO, CA SP IEEE, NPSS, Boeing Co, Lawrence Livermore Natl Lab, MIT, Sandia Natl Lab, Univ California San Diego, Univ Illinois AB We present a conceptual design for a 400 J, 5 Hz, KrF laser to develop the technologies required for inertial fusion energy. The Issues that need to be addressed are lifetime, efficiency and cost. Areas that need development are the emitter, the foil support (hibachi), the pulse power driver, the optics, and laser gas conditioning system. We have identified enabling technologies for each, and developed a program plan to combine them in a single Integrated test. C1 USN, Res Lab, Div Plasma Phys, Washington, DC 20375 USA. RP Sethian, JD (reprint author), USN, Res Lab, Div Plasma Phys, Washington, DC 20375 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 0-7803-4226-7 PY 1998 BP 593 EP 597 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Nuclear Science & Technology; Physics GA BL48U UT WOS:000075681300127 ER PT B AU Johnson, WN Grove, JE Philips, BF Norris, JP Moiseev, AA AF Johnson, WN Grove, JE Philips, BF Norris, JP Moiseev, AA BE Nalcioglu, O TI A CsI(Tl) hodoscopic calorimeter for the GLAST mission 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 The Gamma-ray Large Area Space Telescope (GLAST) is a NASA mission concept under development by an international team for a possible new mission start in the year 2001, The instrument operates as an e(+)e(-) pair conversion telescope and supporting calorimeter imaging gamma rays in the 10 MeV to 300 GeV energy range, The baseline design consists of a modular array of e(+)e(-) pair trackers formed from multiple planes of Silicon strip detectors interleaved with converter foils of ph. A matching array of calorimeters of CsI(TI) are below the trackers, We present here the requirements and simulations of the performance of this imaging calorimeter. C1 USN, Res Lab, Washington, DC 20375 USA. RP Johnson, WN (reprint author), USN, Res Lab, Washington, DC 20375 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 0-7803-4259-3 PY 1998 BP 27 EP 31 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:000074401900007 ER PT B AU Kurfess, JD AF Kurfess, JD BE Nalcioglu, O TI Compton scatter imaging in astrophysics 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 Compton telescopes have been an important tool in gamma ray astronomy, most recently with the COMPTEL instrument on NASA's COMPTON Gamma Ray Observatory (CGRO). Scientific objectives in low/medium energy gamma ray astronomy place highest priority on significant improvement in sensitivity relative to CGRO and ESA's planned INTEGRAL mission. The observational requirements include both discrete and extended sources, and narrow, broad, and continuum spectral features. A high spectral and spatial resolution Compton telescope is the preferred instrument for a future mission. The broad range of scientific objectives that such a mission will address include: mapping radioactivity across the Galaxy (Al-26, Ti-44, Fe-60), detection of several Type Ia supernovae per year (Ni-56, Co-56), study nuclear burning in novae (Na-22, Be-7, 511 keV), study the accretion of matter onto galactic and massive extra-galactic black holes and clarification of the mechanism for the formation of relativistic jets; provide unique insights into the structure of neutron stars, cosmic gamma ray bursts; and solar flares. A mission to achieve these broad goals should have narrow line sensitivities approaching 10(-7) gamma/cm(2)-s for discrete sources. An energy threshold of similar to 250 keV is required to ensure good coverage of the many important astrophysical gamma ray lines from 511 keV to 2 MeV. Angular resolutions much better than 1 degree are required. Detectors which combine state of the art energy resolution (few keV) and spatial resolution (1 mm) are needed. A major breakthrough in background reduction and sensitivity could be realized if tracking low-energy electrons (similar to 100 keV) can be achieved. C1 USN, Res Lab, Washington, DC 20375 USA. RP Kurfess, JD (reprint author), USN, Res Lab, Washington, DC 20375 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 315 EP 319 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:000074401900067 ER PT B AU Phillips, GW AF Phillips, GW BE Nalcioglu, O TI Applications of Compton imaging in nuclear waste characterization and treaty verification 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 Compton imaging systems have a number of advantages for characterization of nuclear waste, such as identifying hot spots in mixed waste in order to reduce the volume of high-level waste requiring extensive treatment or long-term storage, and imaging large objects or contaminated areas. Compton imaging also has potential applications for monitoring production, deployment, shipping and storage of nuclear warheads and components in the verification of treaties such as START I and II, the Comprehensive Test Ball Treaty and the Non-Proliferation Treaty. This article presents a brief historical perspective and discusses system design requirements and performance specifications for these applications. The advantages of Compton imaging are compared to competing imaging technologies. C1 USN, Res Lab, Washington, DC 20375 USA. RP Phillips, GW (reprint author), USN, Res Lab, Washington, DC 20375 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 362 EP 364 PG 3 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:000074401900077 ER PT B AU Lovellette, MN Wood, KS Williamson, R Michelson, PF AF Lovellette, MN Wood, KS Williamson, R Michelson, PF BE Nalcioglu, O TI Distributed data processing in the GLAST instrument 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 The Gamma-ray Large Area Space Telescope (GLAST) requires extensive on-board computing capabilities to reduce the maximum data rate of 50 Mbps to a tractable 100 - 200 Kbps that can be stored on-board for later downlink. The modular nature of the GLAST instrument leads to a distributed processing topology that can be implemented in a way that also provides the redundant functionality required for a major space instrument. This system can be produced using technologies that are currently available, and that have either already been flown in space, or that will fly shortly. C1 USN, Res Lab, Washington, DC 20375 USA. RP Lovellette, MN (reprint author), USN, Res Lab, Washington, DC 20375 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 605 EP 609 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:000074401900129 ER PT B AU Kroeger, RA Johnson, WN Kurfess, JD Schwarz, WG Read, ME Allen, MD Alley, GT Britton, CL Clonts, LC Ericson, MN Simpson, ML AF Kroeger, RA Johnson, WN Kurfess, JD Schwarz, WG Read, ME Allen, MD Alley, GT Britton, CL Clonts, LC Ericson, MN Simpson, ML BE Nalcioglu, O TI CMOS readout system for a double-sided germanium strip detector 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 wide variety of applications require a hard Xray or gamma ray detector which combine both good spatial resolution and energy resolution. Double-sided solid-state strip detectors provide this capability. We report on the development of CMOS electronics designed for photon detection with strip detectors. These electronics include a low noise preamplifier, semi-gaussian shaping amplifier, discriminator, and peak detection circuitry. All circuits are designed to operate at low power. Circuits have been duplicated in both NMOS and PMOS to provide both polarities of signals, We have constructed an 8x8 channel system to test these prototype chips. Power consumption for the preamplifier through peak-detector circuit is 4 mW/channel. The test system has a conversion gain of -35 mV/fC, system noise (equivalent noise charge) of ENC<220 e rms (0 pF), and a dynamic range of >100:1 in both NMOS and PMOS circuits. C1 USN, Res Lab, Washington, DC 20375 USA. RP Kroeger, RA (reprint author), USN, Res Lab, Washington, DC 20375 USA. RI Simpson, Michael/A-8410-2011 OI Simpson, Michael/0000-0002-3933-3457 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 691 EP 693 PG 3 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:000074401900148 ER PT S AU Butler, JT Sasao, T AF Butler, JT Sasao, T GP IEEE TI On the properties of multiple-valued functions that are symmetric in both variable values and labels SO 1998 28TH IEEE INTERNATIONAL SYMPOSIUM ON MULTIPLE-VALUED LOGIC - PROCEEDINGS SE INTERNATIONAL SYMP ON MULTIPLE-VALUED LOGIC - PROCEEDINGS LA English DT Proceedings Paper CT 28th International Symposium on Multiple-Valued Logic CY MAY 27-29, 1998 CL FUKUOKA, JAPAN SP IEEE Comp Soc, Tech Comm Multiple Valued Logic, Japan Res Grp Multiple Valued Logic DE symmetric functions; multiple-valued logic; variable/value symmetric functions; minimization AB Functions that are symmetric in both variable labels and variable values are useful as benchmarks for logic minimization algorithms. We present the properties of such functions, showing that they are isomorphic to partitions on n (the number of variables) with no part greater than r (the number of logic values). From this, we enumerate these functions. Further we derive lower bounds, upper bounds, and exact values for the number of prime implicants in the minimal sum-of-products expressions for certain subclasses of these functions. C1 USN, Postgrad Sch, Dept Elect & Comp Engn, Monterey, CA 93943 USA. RP Butler, JT (reprint author), USN, Postgrad Sch, Dept Elect & Comp Engn, Code EC-Bu, Monterey, CA 93943 USA. RI Sasao, Tsutomu/E-9702-2012 NR 0 TC 3 Z9 8 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 SN 0195-623X BN 0-8186-8371-6 J9 INT SYM MVL PY 1998 BP 83 EP 88 DI 10.1109/ISMVL.1998.679299 PG 6 WC Computer Science, Hardware & Architecture; Computer Science, Software Engineering SC Computer Science GA BL09P UT WOS:000074251800014 ER PT B AU Singh, DJ AF Singh, DJ BE Zhang, M Tu, KN TI Electronic structure and properties of novel thermoelectrics from first principles calculations SO 1998 5TH INTERNATIONAL CONFERENCE ON SOLID-STATE AND INTEGRATED CIRCUIT TECHNOLOGY PROCEEDINGS LA English DT Proceedings Paper CT 5th International Conference on Solid-State and Integrated Circuit Technology CY OCT 21-23, 1998 CL BEIJING, PEOPLES R CHINA SP Chinese Inst Electr, IEEE Electron Devices Soc, IEEE Solid State Circuits Soc, Japan Soc Appl Phys, URSI Commiss D, IEE, Electr Div, UK, Korea Inst Telemat & Electr, IEEE Beijing Sect, Mat Res Soc, Natl Nat Sci Fdn China ID SKUTTERUDITE ANTIMONIDES; FILLED SKUTTERUDITES AB The application of first principles calculations based on density functional theory to novel thermoelectric materials is discussed. These calculations give an understanding of the electronic structure and transport coefficients that is often complementary to the view provided by experimental characterization efforts, and which is often useful in identifying promising materials and guiding their optimization. This is illustrated by examples in the skutterudites. C1 USN, Res Lab, Complex Syst Theory Branch, Washington, DC 20375 USA. RP USN, Res Lab, Complex Syst Theory Branch, Washington, DC 20375 USA. RI Singh, David/I-2416-2012 NR 13 TC 0 Z9 0 U1 1 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4306-9 PY 1998 BP 856 EP 859 DI 10.1109/ICSICT.1998.786462 PG 2 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Materials Science, Characterization & Testing; Materials Science, Coatings & Films; Optics SC Engineering; Materials Science; Optics GA BN17C UT WOS:000080928800230 ER PT B AU Papanicolaou, NA Edwards, A Rao, MV Wickenden, AE Koleske, DD Henry, RL Anderson, WT AF Papanicolaou, NA Edwards, A Rao, MV Wickenden, AE Koleske, DD Henry, RL Anderson, WT GP IEEE TI A high temperature vacuum annealing method for forming ohmic contacts to GaN and SiC SO 1998 FOURTH INTERNATIONAL HIGH TEMPERATURE ELECTRONICS CONFERENCE LA English DT Proceedings Paper CT 4th International High Temperature Electronics Conference CY JUN 14-18, 1998 CL ALBUQUERQUE, NM SP USAF, Air Force Res Lab, Sandia Natl Lab, Team Specialty Prod, Cree Res Inc, Honeywell Solid State Electr Ctr, Allied Signal, Northrop Grumman Corp, Electron Devices Soc, Components Packaging & Manufacturing Technol Soc AB In this work we report on the high temperature annealing of Ti/Al and Cr/Al contacts on n-GaN by a vacuum annealing technique. This method consists of annealing the samples on a resistively heated tungsten strip, in vacuum, with an Ar background ambient of 5x10(-5) Torr. Contact resistivities as low as 2.2x10(-5) Omega-cm(2) and 4.1x10(-5) Omega-cm(2) were obtained for Ti/Al and Cr/Al ohmic contact metallizations respectively. Auger profile analysis showed minimal oxidation of the Al surface in the vacuum annealed samples whereas high levels of O were observed in the furnace annealed case. A contact resistivity of 4.3x10(-4) Omega-cm(2) was achieved for Si/Pt metallization on p-SiC. C1 USN, Res Lab, Washington, DC 20375 USA. RP Papanicolaou, NA (reprint author), USN, Res Lab, 4555 Overlook Ave, Washington, DC 20375 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 0-7803-4540-1 PY 1998 BP 122 EP 127 DI 10.1109/HITEC.1998.676772 PG 6 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA BL19G UT WOS:000074636600024 ER PT B AU Anderson, WT AF Anderson, WT GP IEEE TI Reliability of high temperature electronic components SO 1998 FOURTH INTERNATIONAL HIGH TEMPERATURE ELECTRONICS CONFERENCE LA English DT Proceedings Paper CT 4th International High Temperature Electronics Conference CY JUN 14-18, 1998 CL ALBUQUERQUE, NM SP USAF, Air Force Res Lab, Sandia Natl Lab, Team Specialty Prod, Cree Res Inc, Honeywell Solid State Electr Ctr, Allied Signal, Northrop Grumman Corp, Electron Devices Soc, Components Packaging & Manufacturing Technol Soc AB A review is made of high temperature reliability efforts on solid-state electronic components. To date, most of this work has been concerned with high temperature stressing, usually for short periods of time (less than 100 hours) to demonstrate stability. To field high temperature devices in the future, comprehensive high temperature reliability studies will be required. C1 USN, Res Lab, Washington, DC 20375 USA. RP Anderson, WT (reprint author), USN, Res Lab, Washington, DC 20375 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 0-7803-4540-1 PY 1998 BP 148 EP 150 DI 10.1109/HITEC.1998.676777 PG 3 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA BL19G UT WOS:000074636600029 ER PT B AU Mittereder, JA Roussos, JA Anderson, WT AF Mittereder, JA Roussos, JA Anderson, WT GP IEEE ELECTRON DEVICES SOC IEEE ELECTRON DEVICES SOC TI Life testing of GaAs AlGaAs heterojunction bipolar transistors SO 1998 GAAS RELIABILITY WORKSHOP, PROCEEDINGS LA English DT Proceedings Paper CT 1998 GaAs Reliability Workshop CY NOV 01, 1998 CL ATLANTA, GA SP JEDEC JC 14 7 Comm GaAs Reliabil & Qual Stand, IEEE Electron Devices Soc C1 USN, Res Lab, Washington, DC 20375 USA. RP Mittereder, JA (reprint author), USN, Res Lab, Code 6855, Washington, DC 20375 USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7908-0065-9 PY 1998 BP 40 EP 45 DI 10.1109/GAASRW.1998.768034 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BN17S UT WOS:000080979200007 ER PT B AU Weatherford, TR David, G Crites, M Whitaker, JF Jobe, K Ledbetter, EJ Meyer, S Bustamante, M Thomas, S Elliott, K AF Weatherford, TR David, G Crites, M Whitaker, JF Jobe, K Ledbetter, EJ Meyer, S Bustamante, M Thomas, S Elliott, K GP IEEE ELECTRON DEVICES SOC IEEE ELECTRON DEVICES SOC TI In-situ picosecond measurements of InP and GaAsICs utilizing photoconductive sampling probes SO 1998 GAAS RELIABILITY WORKSHOP, PROCEEDINGS LA English DT Proceedings Paper CT 1998 GaAs Reliability Workshop CY NOV 01, 1998 CL ATLANTA, GA SP JEDEC JC 14 7 Comm GaAs Reliabil & Qual Stand, IEEE Electron Devices Soc C1 USN, Postgrad Sch, Monterey, CA 93943 USA. RP Weatherford, TR (reprint author), USN, Postgrad Sch, Code EC-WT, Monterey, CA 93943 USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7908-0065-9 PY 1998 BP 53 EP 55 DI 10.1109/GAASRW.1998.768036 PG 3 WC Engineering, Electrical & Electronic SC Engineering GA BN17S UT WOS:000080979200009 ER PT S AU Song, GB Schmidt, SP Agrawal, BN AF Song, GB Schmidt, SP Agrawal, BN GP IEEE TI Experimental study of active vibration suppression of flexible structure using modular control patch 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 presents experimental results of vibration suppression of a flexible structure using a miniaturized digital controller, called Modular Control Patch (MCP). The MCP employs a TI-C30 digital signal processor and was developed by TRW for the United States Air Force for future space vibration control. In this research, the MCP is used to implement different control algorithms for vibration suppression of a cantilevered aluminum beam with piezoceramic sensors and actuators. Positive Position Feedback (PPF) control, Strain Rate Feedback (SRF) control, and their combinations were implemented. Experiments found that PPF control is most effective for single-mode vibration suppression, and two PPF filters in parallel are most effective for multi-mode vibration suppression. Further experiments demonstrated the robustness of PPF control. PPF can achieve effective vibration suppression when there is a 20% error in modal frequency. C1 USN, Postgrad Sch, Dept Aeronaut & Astronaut, Spacecraft Res & Design Ctr, Monterey, CA 93943 USA. RP Song, GB (reprint author), USN, Postgrad Sch, Dept Aeronaut & Astronaut, Spacecraft Res & Design Ctr, Monterey, CA 93943 USA. NR 0 TC 1 Z9 1 U1 0 U2 2 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 189 EP 201 PG 13 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA BL20E UT WOS:000074664600020 ER PT S AU Stuart, JG Agrawal, BN AF Stuart, JG Agrawal, BN GP IEEE TI Vibration suppression: Reduced-order model/residual mode filter control using smart structures 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 For spacecraft with large flexible antennas, and/or flexible support structures, suppressing vibrations caused by on-orbit operational disturbances (e.g., antenna slew maneuvers and thruster firings) is a challenging problem. In the past several years, advances in smart structure technologies have made their use in real-time dynamic control of a structure possible. This paper discusses analytical investigations that are focused on the development of improved vibration suppression techniques for flexible spacecraft structures using smart structure actuators and sensors. In general, active control of large flexible structures can be used to improve performance, e.g., shape fidelity, line-of-sight pointing accuracy, and vibration and disturbance suppression. Large-scale models of such structures (e.g., finite element models) are appropriate for dynamic simulation but cannot be used as a basis for control algorithms, which must be implemented via computer in real-time. Therefore, control algorithms are often based on Reduced-Order Models (ROM) of the structure dynamics. Whenever such a controller operates in closed-loop with the actual structure, unwanted Controller-Structure Interaction (CSI) occurs due to un-modeled dynamics. CSI can cause performance degradation and even instability. These instabilities can easily be relieved by the use of low-order Residual Mode Filters (RMF). These filters can be added on after the original ROM controller has been designed, and they produce very little degradation of designed performance while yielding an acceptable stability margin for closed-loop operation. The research presented in this paper integrates smart structure control technologies with the ROM-RMF control technique for active vibration control of a flexible spacecraft structure. This smart structure control technique is applied to a model of the U.S. Naval Postgraduate School's Flexible Spacecraft Simulator (FSS). The FSS simulates motion about the pitch axis of a spacecraft, and is comprised of a rigid central body and a reflector supported by a two-link flexible antenna support structure. The flexible arm representing the antenna support structure has two sets of piezoceramic sensors and actuators, which are used for active vibration control. The ROM-RMF control technique, used in conjunction with optimal control laws, is developed for use with these smart sensors and actuators. The performance of this controller is then compared with the performance of other smart structure controllers previously developed for FSS control. C1 USN, Postgrad Sch, Dept Aeronaut & Astronaut, Monterey, CA 93943 USA. RP Stuart, JG (reprint author), USN, Postgrad Sch, Dept Aeronaut & Astronaut, Monterey, CA 93943 USA. NR 0 TC 2 Z9 3 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 203 EP 213 PG 11 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA BL20E UT WOS:000074664600021 ER PT B AU McMahon, JM AF McMahon, JM GP IEEE TI Fiber lasers, a future technology for lasers in 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 The constraints of operation in space have largely precluded the use of conventional solid-state laser systems for applications including remote sensing, communication relays and active laser radars. A new technology, fiber lasers, may offer all of the needed features at an affordable price. An appealing aspect of the fiber laser is that it does not need a rigid optical bench. Only the output end of the fiber need be held in rigid reference to the optical tracking system. Design, fabrication and testing of the laser resonator is generally the most expensive and longest lead part of the effort for conventional solid-state lasers. Advances in Fiber Optic technology and devices mean that the "fiber laser" need not be a simple device but may be a complex system employing sophisticated technology such as wavelength selective Bragg reflectors and nonlinear optical frequency shifters. Three companies have recently obtained single-mode outputs of 35-40 watts single mode at 1.03-1.1 microns. C1 USN, Res Lab, Washington, DC 20375 USA. RP McMahon, JM (reprint author), USN, Res Lab, Code 5601, Washington, DC 20375 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 39 EP 45 PG 7 WC Engineering, Aerospace; Remote Sensing SC Engineering; Remote Sensing GA BL20F UT WOS:000074664900004 ER PT B AU Crisp, HE AF Crisp, HE GP IEEE TI Engineering systems in the 21(st) century: Facing the challenge 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 Results from a workshop series sponsored by the U.S. Navy for promoting wise technology investments in the engineering and management of complex systems in the 21(st) century is described. Characteristics of complex systems and systems engineering practices are reviewed. Projected trends, research needs and recommended investment strategies for engineering complex systems are discussed. Current investments by the Office of Naval Research in the Engineering of Complex systems technology program are reviewed in the context of potential to impact the state of practice in engineering large-scale systems. C1 USN, Ctr Surface Warfare, Dahlgren Div, Dahlgren, VA 22448 USA. RP Crisp, HE (reprint author), USN, Ctr Surface Warfare, Dahlgren Div, 17320 Dahlgren Rd, Dahlgren, VA 22448 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 457 EP 465 PG 9 WC Engineering, Aerospace; Remote Sensing SC Engineering; Remote Sensing GA BL20F UT WOS:000074664900039 ER PT B AU Bruce, S Rice, C Hepp, R AF Bruce, S Rice, C Hepp, R GP IEEE TI Design and test of military cockpits 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 The information technology revolution has had, and will continue to have, as profound of an effect on military cockpit design as it has affected modern culture. The abundance of information available to the pilot from on-board and off-board sensors has the capability of easily overwhelming the pilot. The additional requirements of performing the military mission and operating in a military environment all combine to make designing and testing military cockpits difficult. C1 USN, Air Syst Command, Patuxent River, MD 20670 USA. RP Bruce, S (reprint author), USN, Air Syst Command, Patuxent River, MD 20670 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 5 EP 14 PG 10 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Remote Sensing SC Engineering; Remote Sensing GA BL20G UT WOS:000074665000001 ER PT B AU Schreck, PC AF Schreck, PC GP IEEE TI Demonstration of a gimbal mounted, high resolution charge coupled device (CCD) television camera in lieu of direct view optics for air to ground targeting 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 The process of air to ground targeting for military attack aircraft involves three distinct, sequential phases of visual discrimination: detection, recognition, and identification (DRI). The intent of this paper is to discuss the tactical merits of charged coupled device (CCD) technology in air to ground target DRI, while contrasting the limitations imposed by the loss of direct view optics (DVO). During an extensive flight and ground test program conducted at the Naval Air Warfare Center Aircraft Division, Patuxent River, MD from October, 1996 to February 1997, an experimental airborne electo-optical targeting sensor suite featuring high resolution CCD cameras was evaluated by direct comparison to an existing system based on DVO. The results indicated superior performance of the CCD cameras in low ambient lighting conditions, but the absence of color was a major hindrance to rapid target area acquisition. Test results indicated that high resolution and magnification are not the most critical design criteria for an airborne electo-optical targeting suite; human factors must influence the design based upon a thorough, systematic analysis conducted during flight test. C1 USN, Rotary Wing Aircraft Test Squadron, Unit 1, Patuxent River, MD 20653 USA. RP Schreck, PC (reprint author), USN, Rotary Wing Aircraft Test Squadron, Unit 1, 222755 Saufley Rd, Patuxent River, MD 20653 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 17 EP 27 PG 11 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Remote Sensing SC Engineering; Remote Sensing GA BL20G UT WOS:000074665000002 ER PT B AU Carico, D AF Carico, D GP IEEE TI Rotorcraft flight test automation - The saga continues ... 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 The cost associated with the next generation rotorcraft testing, training, and support, using current techniques, promises to escalate in a predicted hostile fiscal environment. Aircraft testing, and the associated training and support, place large demands on flight vehicles, avionics, weapons systems, test teams and scarce fiscal resources. Innovative technology options in the form of case based reasoning, automatic test plan and test report generation, intelligent documents, intelligent interfaces, and test plan rehearsal options can be used to assist flight test plan development, test reporting, and test data analysis. Integrating an enhanced generic structure, physics-based simulation model with the flight test automation software presents an option to run the test analytically while the test plan is being generated. The initial results include the capability to generate a comprehensive rotorcraft test plan, including related lesson learned, in approximately 15 minutes, on a personal computer at the test team work area. If the personal computer is tied into a workstation based comprehensive aircraft simulation program via a network, then selected tests from the test plan flight test matrix can be run analytically to give test team members a preview of what results to expect from the actual flight test. This flight test automation concept presents one option to enable rotorcraft flight testing to be done better, faster, cheaper, and safer. The work has been sponsored by a variety of low-key in-house, direct tasking, and small business initiatives and the rotorcraft flight test automation saga continues. C1 USN, Air Warfare Ctr, Div Aircraft, Unit 1, Patuxent River, MD 20670 USA. RP Carico, D (reprint author), USN, Air Warfare Ctr, Div Aircraft, Unit 1, Bldg 2113,22717 Saufley Rd, Patuxent River, MD 20670 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 29 EP 38 PG 10 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Remote Sensing SC Engineering; Remote Sensing GA BL20G UT WOS:000074665000003 ER PT B AU Girard, MM McIntosh, S AF Girard, MM McIntosh, S GP IEEE TI Flutter testing in the 90's - (The GBU-24 saga) 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 Operation Desert Storm demonstrated the benefits of employing large guided, penetrating weapons with long standoff ranges against hardened targets. The Canadian Forces (CF) identified a requirement to employ Precision Guided Munitions (PGM) on the CF-18 and one of the weapons under consideration was the GBU-24B/B Laser Guided Bomb (LGB). Prior to the initiation of the flight test program, a detailed Butter analysis study indicated that certain CF-18/GBU-24 configuations exhibited a 5.6 Hz antisymmetric Butter mechanism It was therefore recommended that a flutter/limit cycle oscillation (LCO) flight test be conducted prior to Beet release of the GBU-24. C1 USN, Air Warfare Ctr, Div Aircraft, Project Off F18, Patuxent River, MD 20653 USA. RP Girard, MM (reprint author), USN, Air Warfare Ctr, Div Aircraft, Project Off F18, Bldg 115,Suite 3A,22080 Elmer Rd, Patuxent River, MD 20653 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 39 EP 50 PG 12 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Remote Sensing SC Engineering; Remote Sensing GA BL20G UT WOS:000074665000004 ER PT B AU Horan, DM AF Horan, DM GP IEEE TI Clementine in retrospect 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 Clementine was a joint U.S. Department of Defense (DoD) and National Aeronautics and Space Administration (NASA) mission launched in January 1994. Its primary purpose was to test space hardware developed for the DoD. Its secondary goal was to collect data of scientific value for NASA by imaging the Moon in multiple, narrow visible and infrared passbands from lunar orbit and the asteroid 1620 Geographos during a close fly by. The images of Geographos were not obtained, but the lunar data provided by Clementine far exceeded everyone's expectations in both quality and quantity. C1 USN, Res Lab, Ctr Space Technol, Washington, DC 20375 USA. RP Horan, DM (reprint author), USN, Res Lab, Ctr Space Technol, Washington, DC 20375 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 89 EP 95 PG 7 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Remote Sensing SC Engineering; Remote Sensing GA BL20G UT WOS:000074665000009 ER PT B AU Eadie, JW Hart, S Charette, D Jancic, D AF Eadie, JW Hart, S Charette, D Jancic, D GP IEEE TI Multifunction Electromagnetic Radiating System (MERS) 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 As part of the Navy's Integrated Topside Design effort, the Science and Technology Community initiated several technology demonstrations for the development of reduced signature sensors to produce a low-observable surface combatant. The objective of the Multifunction Electromagnetic Radiating System (MERS) Advanced Technology Demonstration (ATD) is to demonstrate the feasibility of combining at least four shipboard functions (Direction Finding, JTIDS (Joint Tactical Information Data System) transmit and receive, UHF line-of-sight transmit and receive, and IFF (Identification Friend or Foe) transmit and receive) into a single, low observable, light weight antenna system. The principal benefits of this integration are to lower topside weight, dramatically decrease the total number of antennas aloft and decrease the radar cross section contribution of these antenna functions to a negligible level. The key beneficiaries of the MERS technology may include new construction ship programs such as future DDG 51s, DD 21, LPD 17 Class ships, as well as active fleet LHD 1, CG-47 and DDG-51 Class ships. C1 USN, Sea Syst Command, Arlington, VA 22217 USA. RP Eadie, JW (reprint author), USN, Sea Syst Command, Arlington, VA 22217 USA. NR 0 TC 0 Z9 2 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 491 EP 499 PG 9 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Remote Sensing SC Engineering; Remote Sensing GA BL20G UT WOS:000074665000047 ER PT B AU Watson, GA AF Watson, GA GP IEEE TI Multisensor ESA resource management 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 The integration of multiple sensors with an Electronically Scanned Array (ESA) for target tracking and resource management has been intensely investigated, and several effective techniques have been developed. Conventional techniques employ complex, decision-directed logic to select the target revisit interval and adjust the filter process noise to account for target maneuvers, but have the potential to improve performance. For most systems, each sensor provides its information to a central location where the integration occurs. This central track is employed for system decisions and provides a manageable tracking environment but restricts the potential for system improvement. An ESA is highly controllable and has the ability to greatly enhance tracking performance. Resource allocation for an ESA is critical, since it must support multiple functions, and several modern techniques have been developed to enhance its performance as a stand-alone sensor by effectively managing its time-energy budget. The integration of an ESA with other sensors can further enhance the tracking and reduce the resource allocation requirements of the ESA. This paper presents a technique for ESA resource management through the use of multisensor integration that employs the Interacting Multiple Model (IMM) algorithm and the Probabilistic Data Association Filter (PDAF). Simulation results are provided to demonstrate the effectiveness of this modern integration technique. C1 USN, Ctr Surface Warfare, Dahlgren Div, Syst Res & Technol Dept, Dahlgren, VA 22448 USA. RP Watson, GA (reprint author), USN, Ctr Surface Warfare, Dahlgren Div, Syst Res & Technol Dept, Code B32, Dahlgren, VA 22448 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 13 EP 27 PG 15 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Remote Sensing; Optics SC Engineering; Remote Sensing; Optics GA BL20J UT WOS:000074665200002 ER PT B AU Wilson, T Felt, R AF Wilson, T Felt, R GP IEEE TI Hyperspectral Remote Sensing Technology (HRST) program 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 The Office of Naval Research (ONR) and the Naval Research Laboratory (NRL) are currently in the design phase of a program called the Hyperspectral Remote Sensing Technology (HRST) program. HRST will demonstrate the utility of a hyperspectral earth-imaging system to support Naval needs for characterization of the littoral regions of the world. One key component of the HRST program is the development of the Navy EarthMap Observer (NEMO) satellite system to provide a large hyperspectral data base. NEMO will provide images of littoral regions with 210 spectral bands over a bandpass of 0.4 to 2.5 mu m. Since ocean environments have reflectances typically less than 5%, this system requires a very high signal-to-noise ratio (SNR). The NEMO Hyperspectral Imager (HSI) will sample over a 30 km swath width with a 60 m Ground Sample Distance (GSD) with the ability to go to a 30 m GSD by utilizing the systems attitude control system to "nod" (i.e., use image motion compensation/ground motion compensation to slow down the ground track of the field of view). Also included in the payload is a co-registered 5 m panchromatic imager to provide simultaneous high spatial resolution imagery. A sun-synchronous circular orbit of 605 km allows continuous repeat coverage of the whole earth. A unique aspect of the system is the use of a feature extraction and data compression software package developed by NRL called the Optical Real-Time Spectral Identification System (ORASIS). ORASIS employs a parallel, adaptive hyperspectral method for real time scene characterization, data reduction, background suppression, and target recognition. The use of ORASIS is essential for management of the massive amounts of data expected from the NEMO HSI system, and for developing Naval products under HRST. C1 Off Naval Res, Arlington, VA 22217 USA. RP Wilson, T (reprint author), Off Naval Res, 800 N Quincy St, Arlington, VA 22217 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 0-7803-4311-5 PY 1998 BP 193 EP 200 PG 8 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Remote Sensing; Optics SC Engineering; Remote Sensing; Optics GA BL20J UT WOS:000074665200019 ER PT B AU Casey, JP Fessenden, CT Bansal, R AF Casey, JP Fessenden, CT Bansal, R GP IEEE IEEE TI Asymmetrically fed linear antenna for low-angle VHF/UHF satellite communications SO 1998 IEEE-APS CONFERENCE ON ANTENNAS AND PROPAGATION FOR WIRELESS COMMUNICATIONS LA English DT Proceedings Paper CT 1998 IEEE-APS Conference on Antennas and Propagation for Wireless Communications CY NOV 01-04, 1998 CL WALTHAM, MA SP IEEE Boston Section, IEEE Antennas and Propagat Soc, URSI, Anienna Syst & Tech, Appl Microwave & Wireless, Microwave Journal, RF Design C1 USN, Undersea Warfare Ctr, Submarine Electromagnet Syst Dept, Newport, RI 02841 USA. RP Casey, JP (reprint author), USN, Undersea Warfare Ctr, Submarine Electromagnet Syst Dept, Newport, RI 02841 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 0-7803-4955-5 PY 1998 BP 129 EP 132 DI 10.1109/APWC.1998.730672 PG 4 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA BM30A UT WOS:000078318200033 ER PT B AU Anderson, JL Figuerres, ZE Hovakemian, A AF Anderson, JL Figuerres, ZE Hovakemian, A GP IEEE IEEE TI Using ATE simulation to develop test procedures and verify testability for the STANDARD Missile 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 STANDARD Missile (SM) program has historically used traditional methods to develop new Automatic Equipment (ATE). The Test Equipment (TE) hardware was built and then came the long, difficult task of developing test Software. The Navy needs a better way to develop the next generation of TE. This paper describes how ATE simulation should be used throughout the lifecycle of the program to accelerate development schedules and reduce overall costs. Simulation models are widely used in developing complex missile hardware but not for developing ATE hardware. Using ATE simulation models in conjunction with missile simulation models would provide the following capabilities: Develop test procedures without the need for expensive ATE and missile hardware. Find testability problems before the missile or ATE hardware is built Develop and verify Built-in-Test (BIT). Verify missile and ATE changes throughout missile production. Determine why ATE testing did not find problems causing flight failures. C1 USN, Warfare Assessment Stn MS 11, Corona, CA 91718 USA. RP Anderson, JL (reprint author), USN, Warfare Assessment Stn MS 11, POB 5000, Corona, CA 91718 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 28 EP 34 DI 10.1109/AUTEST.1998.713416 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:000076427600005 ER PT B AU Preiss, SA AF Preiss, SA GP IEEE IEEE TI A new approach to Navy ship munitions BIT and reprogramming 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 offers insight into the challenges of the modern day Navy munitions BIT and reprogramming process. With the land based Navy depot quickly becoming a scarce commodity in this day and age of downsizing and streamlining, the Navy carrier fleet and its personnel are assuming more of the land based depot duties and responsibilities. The Common Munitions BIT Reprogramming Equipment (CMBRE) is an interservice tester which embodies all the elements of the "new" procurement process. The CMBRE is used to initiate BIT and provide BIT status for a variety of MIL-STD-1760 munitions in the Navy fleet. The CMBRE can also up load, down load, and verify applicable software including Operational Flight Programs (OFPs) and mission planning data. The Joint Direct Attack Munitions (JDAM) will be the first weapon employed in consonance with the CMBRE to be permanently deployed on aircraft carriers. These two programs will be the first to employ ship ordnance personnel to BIT and reprogram "live" munitions on board ship. This paper offers a management and technical perspective into how this new approach is being accomplished as both programs boldly lead the way into the 21st century. C1 USN, Air Warfare Ctr, Weapons Div, Engn & Acquisit Branch,Weapons & Targets Support, Point Mugu, CA 93042 USA. RP Preiss, SA (reprint author), USN, Air Warfare Ctr, Weapons Div, Engn & Acquisit Branch,Weapons & Targets Support, Point Mugu, CA 93042 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 83 EP 90 DI 10.1109/AUTEST.1998.713425 PG 8 WC Engineering, Aerospace; Engineering, Multidisciplinary; Engineering, Electrical & Electronic; Instruments & Instrumentation; Medical Informatics; Transportation SC Engineering; Instruments & Instrumentation; Medical Informatics; Transportation GA BL72A UT WOS:000076427600014 ER PT B AU Davis, RJ Harrison, J AF Davis, RJ Harrison, J GP IEEE IEEE TI Failure Investigation/Evaluation System & Technical Aides (FIESTA) 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 FAILURE INVESTIGATION EVALUATION SYSTEM & TECHNICAL AIDES, (FIESTA) tool set consists of three parts; the Fault Isolation Expert component a system alignment monitor and the "WEB interface" collection of supporting technical resources. FIESTA is a Decision Support Software application. This product is being developed by the Port Hueneme Detachment of the Naval Surface Warfare Center (PHD-NSWC), Missile Systems Department, Port Hueneme, California. Its purpose is to automate missile and test set troubleshooting and diagnostic processes for the US Navy's Standard Missile operational test community. Specifically, it was developed to import, manipulate, process and display test data from the Standard Missile Mark 612 Mod 4 test system. It is built exclusively with "Off the Shelf" Microsoft components. Following are some of the key benefits. Provides test set operators and maintenance personnel with a diagnostic tool to reduce troubleshooting time. Supplies PHD-NSWC's engineers & technicians with a training tool to improve diagnostic skills. Provides PHD-NSWC's Test Improvement Team with a tool for evaluating effectiveness and efficiency of current test software. maintenance to reduce Reduces dependency on test set experts and reduce the need for Field Service Assistance calls. Improves Runs to Go statistics. Minimizes unnecessary rework of missile rounds due to faulty diagnosis Contains an intelligent component that gathers failure resolution data, and incorporates it into the Model for future benefit Serves as a statistical process control fool. Analyzes test system software to identify areas of improvement; ie. deletion of unnecessary tests, implementation of smarter algorithms. C1 USN, Ctr Surface Warfare, Port Hueneme Div, Missile Syst Dept, Port Hueneme, CA 93043 USA. RP Davis, RJ (reprint author), USN, Ctr Surface Warfare, Port Hueneme Div, Missile Syst Dept, Port Hueneme, CA 93043 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 171 EP 174 DI 10.1109/AUTEST.1998.713440 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:000076427600029 ER PT B AU Molnar, JA AF Molnar, JA GP IEEE IEEE TI Navy initiatives to steer COTS instrument technology developments 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 Navy has purchased commercial-off-the-shelf (COTS) test instrumentation (general purpose electronic test equipment - GPETE) for over 25 years. Over that period, the Navy has actively engaged the test equipment industry in technical discussions to support technical requirements for instrumentation. A strong customer-supplier relationship has developed that has allowed the Navy to ensure instrument support for emerging requirements using COTS equipment. New Navy initiatives in instrumentation are focused on supporting improvements in training, extending calibration intervals, automation, and interoperability. These initiatives are being pursued to enhance the Navy's position for a future that will include fewer personnel on ships. The budget for training personnel will be radically constrained; thus, self-training instrumentation will be required. The limited number of personnel will require their instrumentation to be available for longer periods without calibration. Instruments of the future must accommodate automation in an integrated weapons system environment and be able to provide information and raw data back to centralized resources through advanced communications networks. This paper describes the focus of these initiatives for the future Navy. C1 USN, Res Lab, Syst Instrumentat & Integrat Sect, Washington, DC 20375 USA. RP Molnar, JA (reprint author), USN, Res Lab, Syst Instrumentat & Integrat Sect, 4555 Overlook Ave SW, Washington, DC 20375 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 262 EP 271 DI 10.1109/AUTEST.1998.713455 PG 10 WC Engineering, Aerospace; Engineering, Multidisciplinary; Engineering, Electrical & Electronic; Instruments & Instrumentation; Medical Informatics; Transportation SC Engineering; Instruments & Instrumentation; Medical Informatics; Transportation GA BL72A UT WOS:000076427600044 ER PT B AU Molnar, JA AF Molnar, JA GP IEEE IEEE TI Analysis of curve tracer instruments for fault location 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 A review of testability, fault isolation algorithms, and fault simulation techniques is performed. Within the context of established theoretical and simulation analysis methods for fault isolation, the use of curve tracer instruments is analyzed curve tracer instruments are extensively employed by the military, in repair environments, to aid technicians in the isolation and repair of failed circuit boards. An example circuit is analyzed for testability The circuit is simulated and the results are compared to results taken from a curve tracer instrument. The results are discussed and the implications for deployment of curve tracer instruments as general fault diagnostic aids for electronic component repair are presented. electronic component repair are presented. C1 USN, Res Lab, Syst Instrumentat & Integrat Sect, Washington, DC 20375 USA. RP Molnar, JA (reprint author), USN, Res Lab, Syst Instrumentat & Integrat Sect, 4555 Overlook Ave SW, Washington, DC 20375 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 284 EP 291 DI 10.1109/AUTEST.1998.713458 PG 8 WC Engineering, Aerospace; Engineering, Multidisciplinary; Engineering, Electrical & Electronic; Instruments & Instrumentation; Medical Informatics; Transportation SC Engineering; Instruments & Instrumentation; Medical Informatics; Transportation GA BL72A UT WOS:000076427600047 ER PT B AU Bearse, TM Dill, HH Lynch, ML AF Bearse, TM Dill, HH Lynch, ML GP IEEE IEEE TI Application of model based diagnostics to telecommunication satellites 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 describer the successful transfer of U.S. Navy Integrated Diagnostics Support System (IDSS) test and diagnostics technology to industry via the Cooperative Research and Development Agreement (CRADA) process. The primary focus of the joint effort was the development of a new tool, Processing Tool for Event Response Messages (PTERM), which will be used lo perform Iridium (R) satellite diagnostics. This paper presents the Iridium (R) application and a description of the new tool. C1 USN, Undersea Warfare Ctr Div, Newport, RI 02841 USA. RP Bearse, TM (reprint author), USN, Undersea Warfare Ctr Div, Newport, RI 02841 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 392 EP 397 DI 10.1109/AUTEST.1998.713473 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:000076427600062 ER PT B AU Allen, D AF Allen, D GP IEEE IEEE TI Why testing sometimes doesn't work 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 failure of a test to detect a problem in the unit ender test usually results from unanticipated fault modes and inappropriate test design techniques. Resulting corrective and preventative measures may load test suites with unnecessary tests. This paper recommends using Duality Function Deployment to verify the test is for the right reason and that correct information is being collected. Guide to how much testing is desirable is provided. C1 USN, Warfare Assessment Stn, Measurement Sci Directorate, Corona, CA 91718 USA. RP Allen, D (reprint author), USN, Warfare Assessment Stn, Measurement Sci Directorate, Code MS-11,POB 5000, Corona, CA 91718 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 647 EP 648 DI 10.1109/AUTEST.1998.713511 PG 2 WC Engineering, Aerospace; Engineering, Multidisciplinary; Engineering, Electrical & Electronic; Instruments & Instrumentation; Medical Informatics; Transportation SC Engineering; Instruments & Instrumentation; Medical Informatics; Transportation GA BL72A UT WOS:000076427600098 ER PT B AU Nelson, HH McDonald, JR AF Nelson, HH McDonald, JR GP IEEE TI Analysis of magnetometer and EMI data for the MTADS program SO 1998 IEEE INTERNATIONAL CONFERENCE ON FUZZY SYSTEMS AT THE IEEE WORLD CONGRESS ON COMPUTATIONAL INTELLIGENCE - PROCEEDINGS, VOL 1-2 LA English DT Proceedings Paper CT IEEE International Conference on Fuzzy Systems at the World Congress on Computational Intelligence (WCCI 98) CY MAY 04-09, 1998 CL ANCHORAGE, AK SP IEEE, Neural Networks Council, Int Neural Network Soc, IEEE, Alaska Sect AB The Multi-sensor Towed Array Detection System (MTADS) provides the capability for rapid, efficient detection of buried unexploded ordnance (UXO). The system consists of two arrays of sensors, total-field magnetometers and time-domain, pulsed-induction sensors, coupled to an extremely precise GPS location system. Data collected in the field are transferred to a workstation-based Data Analysis System for analysis. Anomalies are selected interactively by an operator and fit to a physics-based model. The MTADS has been demonstrated at several prepared test ranges and two live sites. In all cases, probabilities of detection of greater than 95% have been achieved. The outstanding research issues in this program involve discrimination between UXO and fragments and scrap. Up to two thirds of the costs of a remediation effort result from digging holes that do not contain UXO. Even small improvements in classification ability will lead to large savings in real world operations. C1 USN, Res Lab, Code 6110, Washington, DC 20375 USA. RP Nelson, HH (reprint author), USN, Res Lab, Code 6110, Washington, DC 20375 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 0-7803-4863-X PY 1998 BP 241 EP 245 PG 5 WC Computer Science, Artificial Intelligence SC Computer Science GA BL20P UT WOS:000074668800043 ER PT B AU Nguyen, CT Ganesh, C Gong, KF AF Nguyen, CT Ganesh, C Gong, KF GP IEEE TI A fuzzy logic-based intelligent controller for contact management data integration SO 1998 IEEE INTERNATIONAL CONFERENCE ON FUZZY SYSTEMS AT THE IEEE WORLD CONGRESS ON COMPUTATIONAL INTELLIGENCE - PROCEEDINGS, VOL 1-2 LA English DT Proceedings Paper CT IEEE International Conference on Fuzzy Systems at the World Congress on Computational Intelligence (WCCI 98) CY MAY 04-09, 1998 CL ANCHORAGE, AK SP IEEE, Neural Networks Council, Int Neural Network Soc, IEEE, Alaska Sect AB This paper is concerned with the problem of intelligent control in the selection of data, models, and processing alternatives for contact management data integration. A fuzzy-logic based system, developed for automating this selection process under uncertainty, is presented. This involves the application of a network of fuzzy inference systems and a knowledge-based decision algorithm, and is implemented as a process controller. The process controller is designed to provide decision support within a hierarchical data processing framework. Two fuzzy inference systems are detailed for inferring information essential to data integration which includes system observability and contact kinematics. In addition, a novel technique for handling uncertainty in the input data to a fuzzy inference system is summarized. Experimental results, using simulated data, are presented to demonstrate the effectiveness of this concept. Recommendations for future research are also included. C1 USN, Undersea Warfare Ctr, Newport, RI 02841 USA. RP Nguyen, CT (reprint author), USN, Undersea Warfare Ctr, Newport, RI 02841 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 0-7803-4863-X PY 1998 BP 879 EP 884 PG 6 WC Computer Science, Artificial Intelligence SC Computer Science GA BL20P UT WOS:000074668800156 ER PT B AU Kersten, PR Keller, JM AF Kersten, PR Keller, JM GP IEEE TI Robust fuzzy snakes SO 1998 IEEE INTERNATIONAL CONFERENCE ON FUZZY SYSTEMS AT THE IEEE WORLD CONGRESS ON COMPUTATIONAL INTELLIGENCE - PROCEEDINGS, VOL 1-2 LA English DT Proceedings Paper CT IEEE International Conference on Fuzzy Systems at the World Congress on Computational Intelligence (WCCI 98) CY MAY 04-09, 1998 CL ANCHORAGE, AK SP IEEE, Neural Networks Council, Int Neural Network Soc, IEEE, Alaska Sect AB Flexible closed deformable contours extracted from images to represent object outlines are often called snakes. This paper explores and extends the use of snakes to extract contour features from images for modeling and pattern recognition. A recent paper has shown that many of the contour extraction algorithms have a common formulation as a constrained optimization problem. One version, called the constrained fuzzy clustering algorithm, links fuzzy clustering told snakes - the resulting contour being called a fuzzy snake. These extraction procedures art! vulnerable to noise, which makes their application to noisy sensor images problematic. By applying known robust fuzzy clustering algorithms, more noise resistant snakes can be derived thereby extending contour feature extraction to sensor images. C1 USN, Air Warfare Ctr, Weap Div, Target Recognit Sect,Code 452320D, China Lake, CA 93555 USA. RP Kersten, PR (reprint author), USN, Air Warfare Ctr, Weap Div, Target Recognit Sect,Code 452320D, China Lake, CA 93555 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 0-7803-4863-X PY 1998 BP 1554 EP 1559 PG 6 WC Computer Science, Artificial Intelligence SC Computer Science GA BL20P UT WOS:000074668800270 ER PT S AU Bishop, BE Spong, MW AF Bishop, BE Spong, MW GP IEEE TI Toward 3D uncalibrated monocular visual servo SO 1998 IEEE INTERNATIONAL CONFERENCE ON ROBOTICS AND AUTOMATION, VOLS 1-4 SE IEEE INTERNATIONAL CONFERENCE ON ROBOTICS AND AUTOMATION LA English DT Proceedings Paper CT IEEE International Conference on Robotics and Automation CY MAY 16-20, 1998 CL KATHOLIEKE UNIV LEUVEN, LEUVEN, BELGIUM SP IEEE, Robot & Automat Soc, Consiglio Nazl Ric, Fund Sci Res, Flanders, Belgium, Fraunhofer Inst Produktionstechnik & Automatisier, Commiss European Communities, INRIA, BULL, CNES, DAIMLER, KUKA, MATRA, SIEMENS, TECNOSPAZIO, THOMSON-CSF HO KATHOLIEKE UNIV LEUVEN AB This work is an initial step toward combining control theory with computer vision for the case of uncalibrated monocular (or single-camera) three-dimensional manipulation. We investigate an achievable control goal using a novel image measure and derive a sampled-data control system that results in quick convergence of the end-effector trajectory to a depth-invariant velocity subspace in the camera coordinate frame. We also discuss how this uncalibrated behavior can be used to perform on-line calibration. C1 USN Acad, Annapolis, MD 21402 USA. RP Bishop, BE (reprint author), USN Acad, Annapolis, MD 21402 USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1050-4729 BN 0-7803-4300-X J9 IEEE INT CONF ROBOT PY 1998 BP 2664 EP 2669 PG 2 WC Automation & Control Systems SC Automation & Control Systems GA BL12F UT WOS:000074368900423 ER PT S AU Schultz, AC Adams, W AF Schultz, AC Adams, W GP IEEE TI Continuous localization using evidence grids SO 1998 IEEE INTERNATIONAL CONFERENCE ON ROBOTICS AND AUTOMATION, VOLS 1-4 SE IEEE INTERNATIONAL CONFERENCE ON ROBOTICS AND AUTOMATION LA English DT Proceedings Paper CT IEEE International Conference on Robotics and Automation CY MAY 16-20, 1998 CL KATHOLIEKE UNIV LEUVEN, LEUVEN, BELGIUM SP IEEE, Robot & Automat Soc, Consiglio Nazl Ric, Fund Sci Res, Flanders, Belgium, Fraunhofer Inst Produktionstechnik & Automatisier, Commiss European Communities, INRIA, BULL, CNES, DAIMLER, KUKA, MATRA, SIEMENS, TECNOSPAZIO, THOMSON-CSF HO KATHOLIEKE UNIV LEUVEN AB Evidence grids provide a uniform representation for fusing temporally and spatially distinct sensor readings. However, the use of evidence grids requires that the robot be localized within its environment. Odometry errors typically accumulate over time, making localization estimates degrade, and introducing significant errors into evidence grids as they are built. We have addressed this problem by developing a method for "continuous localization", in which the robot corrects its localization estimates incrementally and on the fly. Assuming the mobile robot has a map of its environment represented as an evidence grid, localization is achieved by building a series of "local perception grids" based on localized sensor readings and the current odometry, and then registering the focal and global grids. The registration produces an offset which is used to correct the odometry. Results are given on the effectiveness of this method, and quantify the improvement of continuous localization over dead reckoning. We also compare different techniques for matching evidence grids and for searching registration offsets. C1 USN, Res Lab, Ctr Appl Res Artificial Intelligence, Washington, DC 20375 USA. RP Schultz, AC (reprint author), USN, Res Lab, Ctr Appl Res Artificial Intelligence, Washington, DC 20375 USA. NR 0 TC 42 Z9 45 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1050-4729 BN 0-7803-4300-X J9 IEEE INT CONF ROBOT PY 1998 BP 2833 EP 2839 PG 3 WC Automation & Control Systems SC Automation & Control Systems GA BL12F UT WOS:000074368900450 ER PT S AU Yamauchi, B Schultz, A Adams, W AF Yamauchi, B Schultz, A Adams, W GP IEEE TI Mobile robot exploration and map-building with continuous localization SO 1998 IEEE INTERNATIONAL CONFERENCE ON ROBOTICS AND AUTOMATION, VOLS 1-4 SE IEEE INTERNATIONAL CONFERENCE ON ROBOTICS AND AUTOMATION LA English DT Proceedings Paper CT IEEE International Conference on Robotics and Automation CY MAY 16-20, 1998 CL KATHOLIEKE UNIV LEUVEN, LEUVEN, BELGIUM SP IEEE, Robot & Automat Soc, Consiglio Nazl Ric, Fund Sci Res, Flanders, Belgium, Fraunhofer Inst Produktionstechnik & Automatisier, Commiss European Communities, INRIA, BULL, CNES, DAIMLER, KUKA, MATRA, SIEMENS, TECNOSPAZIO, THOMSON-CSF HO KATHOLIEKE UNIV LEUVEN AB Our research addresses how to integrate exploration and localization for mobile robots. A robot exploring and mapping an unknown environment needs to know its own location, but it may need a map in order to determine that location. In order to solve this problem, we have developed ARIEL, a mobile robot system that combines frontier-based exploration with continuous localization. ARIEL explores by navigating to frontiers, regions on the boundary between unexplored space and space that is known to be open. ARIEL finds these regions in the occupancy grid map that it builds as it explores the world. ARIEL localizes by matching its recent perceptions with the information stored in the occupancy grid. We have implemented ARIEL on a real mobile robot and rested ARIEL in a real-world office environment. We present quantitative results that demonstrate that ARIEL can localize accurately while exploring, and thereby build accurate maps of its environment. C1 USN, Res Lab, Ctr Appl Res Artificial Intelligence, Washington, DC 20375 USA. RP Yamauchi, B (reprint author), USN, Res Lab, Ctr Appl Res Artificial Intelligence, Washington, DC 20375 USA. NR 0 TC 61 Z9 63 U1 0 U2 3 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1050-4729 BN 0-7803-4300-X J9 IEEE INT CONF ROBOT PY 1998 BP 3715 EP 3720 PG 6 WC Automation & Control Systems SC Automation & Control Systems GA BL12F UT WOS:000074368900590 ER PT S AU Kang, W Xi, N AF Kang, W Xi, N GP IEEE IEEE IEEE IEEE TI "Sensor-Referenced motion planning and dynamic control for mobile robots 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 A new design method for non-time based tracking controller is presented. The key to the non-time based control method is the introduction of a suitable action or motion reference variable other than time, which is directly related to the desired and measurable system output. It enables the construction of control systems with integrated planning capability, in which planning becomes real-time closed-loop process. The new design method converts a controller designed by traditional time-based approach to a non-time based controller using action reference. It significantly simplifies the design procedure. The design method is exemplified by a unmanned vehicle tracking control problem. The design procedure and simulation results demonstrate the advantages of proposed method. C1 USN, Postgrad Sch, Dept Math, Monterey, CA 93943 USA. RP Kang, W (reprint author), USN, Postgrad Sch, Dept Math, Monterey, CA 93943 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 427 EP 432 PG 6 WC Computer Science, Cybernetics SC Computer Science GA BL88E UT WOS:000077033700075 ER PT S AU McCoy, WL AF McCoy, WL GP IEEE IEEE IEEE IEEE TI Interfacing three complementary technologies: Strategic planning, process modeling, and system dynamics 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 This concept paper explores the utility and feasibility of interfacing three complementary technologies: (1) strategic planning, (2) process modeling, and (3) system dynamics to assist with the engineering of complex computer-based systems. Interfacing these technologies appears especially appropriate and timely. The Government Performance and Results Act of 1993 strives to make federal agencies operate more like businesses by requiring strategic plans and conducting performance audits. Process modeling technology aimed at providing assistance for the Integrated Product and Process Development (IPPD) approach for system development is being developed. In today's environment of perpetual change, a means of effectively predicting the impact of such changes on system development would be valuable. System dynamics modeling provides promise in this area. Since the product of strategic planning can be viewed as improved business and operational processes that will likely undergo major changes in response to events occurring in today's environment, there appears to be a natural synergy between application of these three technologies. This paper addresses exploitation of this natural synergy and hypothesizes that such exploitation would facilitate the development and operation of complex systems over the entire life cycle. C1 USN, Ctr Surface Warfare, Dahlgren Div, Syst Res & Technol Dept, Dahlgren, VA 22448 USA. RP McCoy, WL (reprint author), USN, Ctr Surface Warfare, Dahlgren Div, Syst Res & Technol Dept, Dahlgren, VA 22448 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 2620 EP 2624 PG 5 WC Computer Science, Cybernetics SC Computer Science GA BL88E UT WOS:000077033700457 ER PT B AU Hatfield, MO Slocum, MB Godfrey, EA Freyer, GJ AF Hatfield, MO Slocum, MB Godfrey, EA Freyer, GJ GP IEEE IEEE TI Investigations to extend the lower frequency limit of reverberation chambers 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 As the use of reverberation chambers for electromagnetic effects testing increases there is a growing interest in lowering the minimum useable frequency in a specific chamber. This paper describes a series of measurements to investigate the field uniformity of reverberation chambers in the frequency region below which they have been considered useable. The measurements are part of a continuing program to characterize the overall field uniformity of reverberation chambers as a function of frequency. Measurements were taken using the large reverberation chamber (10.82m x 5.18m x 3.96m) at the Naval Surface Warfare Center, Dahlgren Division at frequencies from 80 MHz to 200 MHz. The commonly accepted guideline yields a lowest useable frequency of 110 MHz for the large chamber. Measurements were also obtained using a small reverberation chamber (1.8m x 1.2m x 0.8m) over 100 MHz frequency bands starting at 300, 400 and 730 MHz. The predicted lowest frequency for the small chamber is 556 MHz. The results suggest that the commonly accepted guideline for defining the lowest useable frequency needs to be revised. A performance based criterion using measured uniformity data appears to have merit for defining the lowest useable frequency for typical operations. The results also suggest that useful testing can be conducted at frequencies below the minimum useable frequency as defined by the commonly accepted guidelines. C1 USN, Ctr Surface Warfare, Syst Electromagnet Effects Branch, Dahlgren, VA 22448 USA. RP Hatfield, MO (reprint author), USN, Ctr Surface Warfare, Syst Electromagnet Effects Branch, Dahlgren, VA 22448 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 20 EP 23 PG 4 WC Engineering, Electrical & Electronic SC Engineering GA BM59X UT WOS:000079200400004 ER PT B AU Anderson, TR AF Anderson, TR GP IEEE IEEE TI Time domain and statistical modeling and of the Barkhausen effect used as a magnetic sensor 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 This research presents a time domain model of the Barkhausen effect as a magnetic field sensor. This type of magnetic field sensor will supplement magnetic field sensors already in use and should have wide applicability in the EMC community. When a silicon steel sheet is placed at the center of a coil, an external magnetic field from a moving magnet will cause the magnetic domain walls to snap and click as they suddenly orient themselves. This sudden orientation of the magnetic domains causes sudden changes in magnetization which produce impulses of emf which can be heard as distinct clicks on a loudspeaker connected to an amplifier and with the amplifier connected to the coil. This sudden orientation of the magnetic domain walls in the presence of an external magnetic field is called the Barkhausen effect. In this paper a time domain model of the Barkhausen effect as a magnetic sensor is presented. Equations are also developed which model Barkhausen effect as a motion sensor by-sensing magnetic fields in a moving reference frame. modeled. The sudden orientation of the magnetic domain described by the Barkhausen effect is mathematically modeled by calculating the energy needed to change the direction of the Bloch wall or the transition layer that separates adjacent domains magnetized in different directions. The spectrum of the Barkhausen effect was theoretically derived. C1 USN, Undersea Warfare Ctr, Div Newport, Newport, RI 02841 USA. RP Anderson, TR (reprint author), USN, Undersea Warfare Ctr, Div Newport, 1176 Howell St, Newport, RI 02841 USA. NR 8 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 361 EP 363 PG 3 WC Engineering, Electrical & Electronic SC Engineering GA BM59X UT WOS:000079200400068 ER PT B AU Anderson, TR Derewiany, CF Obara, MD AF Anderson, TR Derewiany, CF Obara, MD GP IEEE IEEE TI Electrostatic discharge sensitive (ESDS) equipment susceptibility to welding generated electromagnetic fields 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 Concerns regarding damage to electrostatic discharge sensitive (ESDS) equipment, as a result of electromagnetic fields generated by welding processes have been raised. The concern that electromagnetic fields generated during the welding process could damage ESDS equipment is quite real. Guidance for welding in the vicinity of ESDS equipment was required by shipbuilders in order to avoid expensive and time-consuming removal of ESDS equipment prior to welding. In this article, the damage to ESDS equipment from welding generated electromagnetic fields is evaluated. Analysis showed that welding in the vicinity of ESDS equipment is not anticipated to cause damage to internal electronics. Guidelines were developed for welding in the vicinity of ESDS equipment. C1 USN, Div Newport, Undersea Warfare Ctr, Newport, RI 02840 USA. RP Anderson, TR (reprint author), USN, Div Newport, Undersea Warfare Ctr, 1176 Howell St, Newport, RI 02840 USA. NR 8 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 364 EP 367 PG 4 WC Engineering, Electrical & Electronic SC Engineering GA BM59X UT WOS:000079200400069 ER PT B AU Dixon, DS AF Dixon, DS GP IEEE IEEE TI An EMC approach that permits a relaxation of radiated electric field requirements for COTS equipment aboard naval platforms 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 Historically companies developing equipment for the US Navy have had difficulty satisfying the Mil Std 461 RE02/RE102 electric field emission requirements. Since the development of the New Attack Submarine (NSSN) came under Ex-Secretary of Defense Ferry's acquisition reform initiative, the NSSN electromagnetic compatibility Technical Direction Agent (EMCTDA) evaluated and recommended the use of commercial electromagnetic interference (EMI) requirements wherever possible. ({1}) This paper identifies the electromagnetic compatibility (EMC) approach required to mitigate any additional risk incurred by relaxing the electric field emissions requirement for both mission-critical and non-mission-critical equipment and/or systems. C1 USN, Undersea Warfare Ctr, Newport, RI 02840 USA. RP Dixon, DS (reprint author), USN, Undersea Warfare Ctr, Newport, RI 02840 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 403 EP 409 PG 7 WC Engineering, Electrical & Electronic SC Engineering GA BM59X UT WOS:000079200400076 ER PT B AU Javor, ER Anderson, T AF Javor, ER Anderson, T GP IEEE IEEE TI Design of a Helmholtz coil for low frequency magnetic field susceptibility testing 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 This paper describes the design of a Helmholtz coil that is a candidate test apparatus for low frequency magnetic field susceptibility testing on military equipment and subsystems. Use of this coil would reduce electromagnetic compatibility (EMC) qualification test time, and subject the equipment under test (EUT) to a relatively uniform field which is representative of the actual electromagnetic environment on some Naval platforms. Specifically, this paper presents practical analytical expressions that may be used to design a Helmholtz coil for this unique application. Experimental test results for a three foot diameter coil are presented including: maximum magnetic flux density vs. frequency, impedance vs. frequency, resonant frequency behavior and the effect of coil separation distances greater than one radius. C1 USN, Undersea Warfare Ctr, Div Newport, Newport, RI 02840 USA. RP Javor, ER (reprint author), USN, Undersea Warfare Ctr, Div Newport, 1176 Howell St, Newport, RI 02840 USA. NR 9 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 912 EP 917 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BM59X UT WOS:000079200400172 ER PT B AU Dixon, DS Masi, J AF Dixon, DS Masi, J GP IEEE IEEE TI Thin coatings can provide significant shielding against low frequency EMF magnetic fields 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 Both military and commercial organizations have concerns about obtaining electromagnetic shielding performance using materials that maintain long term performance in today's increasingly hostile shipboard and commercial environments. This paper describes the development and testing of several unique coatings consisting of mixtures of semi-conductive and conductive nano-particles of both magnetic and non-magnetic materials. These materials exhibit low frequency shielding characteristics and have demonstrated significant EMI shielding performance against low frequency, near field magnetic sources previously unobtainable using traditional coatings. Shielding performance of over 20 dB for a 100 micron thickness at the 60 Hz powerline frequency has been measured against a solenoidal EMI source. Although performance at the powerline frequencies was the original goal, the validation of performance over a wider frequency band was documented. C1 USN, Ctr Underwater Syst, Newport, RI 02841 USA. RP Dixon, DS (reprint author), USN, Ctr Underwater Syst, Newport, RI 02841 USA. NR 7 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 1035 EP 1040 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BM59X UT WOS:000079200400194 ER PT B AU Johnson, DM Hatfield, MO Slocum, MB Freyer, GJ AF Johnson, DM Hatfield, MO Slocum, MB Freyer, GJ GP IEEE IEEE TI Comparison of RF coupling to passenger aircraft avionics measured on a transport aircraft and in a reverberation chamber 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 This paper describes measurements of the radio frequency (RF) energy coupled to instrumented avionics boxes from a large transport aircraft and a simulated avionics box. The measurements were performed as a part of the experiments lead by Naval Surface Warfare Center, Dahlgren Division (NSWCDD) to investigate the electromagnetic reverberation characteristics of a large transport aircraft. Measurements of the coupling of RF energy to the unpowered, instrumented aircraft and simulated avionics boxes were made when the avionics bay, cockpit and passenger cabin were internally excited with swept CW RF energy from 100 MHz to 6 GHz and mechanical mode-mixing techniques were used. The measurements were then repeated in the reverberation chamber facility at NSWCDD. The tests are intended to demonstrate that the RF coupling characteristics of the aircraft and simulated avionics boxes measured in a reverberation chamber constitute valid descriptions of the same boxes when installed in the aircraft. C1 USN, Ctr Surface Warfare, Dahlgren, VA 22448 USA. RP Johnson, DM (reprint author), USN, Ctr Surface Warfare, 17320 Dahlgren Rd, Dahlgren, VA 22448 USA. NR 6 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 1047 EP 1052 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BM59X UT WOS:000079200400196 ER PT B AU Lynch, RS Willett, PK AF Lynch, RS Willett, PK GP IEEE IEEE TI Testing the statistical similarity of discrete observations using Dirichlet priors SO 1998 IEEE INTERNATIONAL SYMPOSIUM ON INFORMATION THEORY - PROCEEDINGS LA English DT Proceedings Paper CT IEEE International Symposium on Information Theory CY AUG 16-22, 1998 CL MIT, CAMBRIDGE, MA SP IEEE, Informat Theory Soc, Natl Sci Fdn, NASA, USN, Off Naval Res, AT&T, Motorola, Qualcomm, Lucent Technol, Bell Lab Innovat HO MIT AB In this paper the combined Bayes test test, which uses a Dirichlet (noninformative) prior, is used to determine if the underlying statistics of two data populations are the same. Results demonstrate that the combined Bayes test performs better than the more conventional Kolmogoroy-Smirnov test. C1 USN, Undersea Warfare Ctr, Newport, RI 02841 USA. RP Lynch, RS (reprint author), USN, Undersea Warfare Ctr, Code 3124, Newport, RI 02841 USA. EM lynchus@npt.nuwc.navy.miI; willett@mailhost.engr.uconn.edu 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 0-7803-5000-6 PY 1998 BP 144 EP 144 DI 10.1109/ISIT.1998.708736 PG 1 WC Engineering, Electrical & Electronic SC Engineering GA BL58H UT WOS:000075932800142 ER PT B AU Welch, TB Ziemer, RE AF Welch, TB Ziemer, RE GP IEEE TI Simulation of coded MC-DS-CDMA systems SO 1998 IEEE RADIO AND WIRELESS CONFERENCE PROCEEDINGS - RAWCON 98 LA English DT Proceedings Paper CT IEEE Radio and Wireless Conference (RAWCON 98) CY AUG 09-12, 1998 CL COLORADO SPRINGS, CO SP IEEE, Microwave Theory & Techn Soc, IEEE, Pikes Peak Sect AB We use computer simulations to compare the performance improvements associated with coding on a gaussianized BPSK-MC-DS-CDMA system and a non-gaussianized DPSK-MC-DS-CDMA system. The effects of coding on the gaussianized system approach the performance of a coded BPSK system operating in a Gaussian, channel while the non-gaussianized system performance is approximately 4 dB from the coded DPSK system operating in a Gaussian channel. C1 USN Acad, Dept Elect Engn, Annapolis, MD 21402 USA. RP Welch, TB (reprint author), USN Acad, Dept Elect Engn, Annapolis, MD 21402 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 0-7803-4988-1 PY 1998 BP 189 EP 192 DI 10.1109/RAWCON.1998.709168 PG 4 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA BL53D UT WOS:000075789500047 ER PT B AU Smith, CM Nelson, SR Tuovila, SM AF Smith, CM Nelson, SR Tuovila, SM GP IEEE TI Morphological and related image processing techniques for the detection of microcalcifications in mammographic images SO 1998 IEEE SOUTHWEST SYMPOSIUM ON IMAGE ANALYSIS AND INTERPRETATION LA English DT Proceedings Paper CT 1998 IEEE Southwest Symposium on Image Analysis and Interpretation CY APR 05-07, 1998 CL TUCSON, AZ SP Univ Arizona, Univ Arizona Fdn, Arizona State Univ, IEEE, Tucson Sect AB This paper describes a simple technique for locating microcalcifications in digital mammograms. These methods use the fact that many smoothing techniques are never applied to mammograms as they erase the important features. This is turned to an advantage by subtracting the smoothed image from the original, thus leaving only the important features. A variety of smoothers and enhancers are applied to two image data sets, and the results reported. C1 USN, Ctr Surface Warfare, Dahlgren Div, Coastal Syst Srn, Panama City, FL 32401 USA. RP Smith, CM (reprint author), USN, Ctr Surface Warfare, Dahlgren Div, Coastal Syst Srn, Panama City, FL 32401 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 0-7803-4876-1 PY 1998 BP 29 EP 34 DI 10.1109/IAI.1998.666855 PG 4 WC Computer Science, Information Systems; Engineering, Biomedical; Engineering, Electrical & Electronic; Remote Sensing SC Computer Science; Engineering; Remote Sensing GA BK94V UT WOS:000073925500006 ER PT B AU Van Nevel, A AF Van Nevel, A GP IEEE IEEE TI Texture synthesis via matching first and second order statistics of a wavelet frame decomposition SO 1998 INTERNATIONAL CONFERENCE ON IMAGE PROCESSING - PROCEEDINGS, VOL 1 LA English DT Proceedings Paper CT IEEE International Conference on Image Processing CY OCT 04-07, 1998 CL CHICAGO, IL SP IEEE, Signal Proc Soc AB In this novel approach to texture synthesis, a method which relies on matching the first and second order statistics of wavelet subbands is developed. Synthetic textures are produced using estimates of the correlation matrices and marginal statistics of a wavelet frame decomposition. Previous work has concentrated on iteratively matching the marginals of a subband decomposition, in the hopes the synthetic texture would capture the long range correlations. Our proposed algorithm goes beyond simple marginal matching, attempting to match the correlation coefficients of the subbands as well. We neglect any interband correlations. The algorithm is relatively fast, and has been developed with an eye to applications in regional compression. C1 USN, Air Warfare Ctr, China Lake, CA 93555 USA. RP Van Nevel, A (reprint author), USN, Air Warfare Ctr, China Lake, CA 93555 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 0-8186-8821-1 PY 1998 BP 72 EP 76 PG 5 WC Engineering, Electrical & Electronic SC Engineering GA BL76B UT WOS:000076642600020 ER PT B AU Creusere, CD AF Creusere, CD GP IEEE IEEE TI Successive coefficient refinement for embedded lossless image compression SO 1998 INTERNATIONAL CONFERENCE ON IMAGE PROCESSING - PROCEEDINGS, VOL 1 LA English DT Proceedings Paper CT IEEE International Conference on Image Processing CY OCT 04-07, 1998 CL CHICAGO, IL SP IEEE, Signal Proc Soc AB We consider here a new approach to successive coefficient refinement which speeds up embedded image compression and decompression. Such speedups aa especially useful when lossless or near lossless image Compression is required because so many refinement bits must be transmitted. Rather than sending a binary; refinement symbol typical of existing embedded coders, our algorithm uses a ternary refinement symbol, allowing the encoder to tell the decoder when its current approximation of a given wavelet coefficient is exact. Thus, both encoder and decoder operate faster because they process fewer refinement symbols, yet the fundamental structure of the refinement process remains unchanged-something that is not true tf a non-binary refinement tree is used instead To implement a complete encoder, we combine the proposed refinement process with Shapiro's embedded zero-tree wavelet(EZW) algorithm. By optimizing this process, speed increases of between 13 and 16% call be realized on the set of test images. C1 USN, Air Warfare Ctr, Weapons Div, China Lake, CA 93555 USA. RP Creusere, CD (reprint author), USN, Air Warfare Ctr, Weapons Div, China Lake, CA 93555 USA. NR 0 TC 0 Z9 0 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 0-8186-8821-1 PY 1998 BP 521 EP 525 PG 5 WC Engineering, Electrical & Electronic SC Engineering GA BL76B UT WOS:000076642600114 ER PT S AU Boos, JB Kruppa, W Park, D Bennett, BR Bass, R Yang, MJ Shanabrook, BV AF Boos, JB Kruppa, W Park, D Bennett, BR Bass, R Yang, MJ Shanabrook, BV GP IEEE IEEE TI Low-voltage, high-speed AlSb/InAs HEMTs 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 We report on the improved low-voltage, high-speed performance of AlSb/InAs HEMTs obtained using variations in doping method and layer design. Unintentionally-doped HEMTs with a 0.6 mu m gate length have a transconductance of 1 S/mm at V-DS = 0.4 V. After removal of the gate bonding pad capacitance from an equivalent circuit, an f(T)Lg product of 38 GHz-mu m is obtained at V-DS = 0.4 V. 0.5 mu m gate-length HEMTs that have Si doping in a very thin (9 Angstrom) InAs layer located in the upper AlSb barrier exhibit high drain current density and an f(T) of 45 GHz at V-DS = 0.4 V. 0.1 mu m gate-length HEMTs that use an As-soak doping method exhibit an f(T) of 230 GHz at V-DS = 0.45 V (after correction for the bonding pad capacitance), the highest value achieved thus far in this material system. C1 USN, Res Lab, Washington, DC 20375 USA. RP Boos, JB (reprint author), USN, Res Lab, Washington, DC 20375 USA. RI Bennett, Brian/A-8850-2008 OI Bennett, Brian/0000-0002-2437-4213 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 671 EP 674 DI 10.1109/ICIPRM.1998.712727 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:000075657000170 ER PT S AU Kruppa, W Boos, JB Magno, R Park, D Bennett, BR Bass, R Keye, D AF Kruppa, W Boos, JB Magno, R Park, D Bennett, BR Bass, R Keye, D GP IEEE IEEE TI Transport measurements on AlSb/InAs nanostructures 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 fabrication and characterization of AlSb/InAs nanostructures are reported. Both basic split-gate and split-gate-based quantum dot structures were examined. Considerable structure in the cryogenic conductance characteristics, including 2e(2)/h staircases and periodic oscillations suggestive of Coulomb blockade, were found. Conductance staircase effects were observed in the basic split-gate structure above 25 K and to about 10 mV of drain bias at 4.2 K. Single-electron tunneling phenomena, probably due to fluctuation potentials, were observed in the dot structure at 4.2 K. C1 USN, Res Lab, Washington, DC 20375 USA. RP Kruppa, W (reprint author), USN, Res Lab, Washington, DC 20375 USA. RI Bennett, Brian/A-8850-2008 OI Bennett, Brian/0000-0002-2437-4213 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 777 EP 780 DI 10.1109/ICIPRM.1998.712778 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:000075657000197 ER PT S AU Xie, GG Hensgen, D Kidd, T Yarger, J AF Xie, GG Hensgen, D Kidd, T Yarger, J GP IEEE TI SAAM: An integrated network architecture for integrated services SO 1998 SIXTH INTERNATIONAL WORKSHOP ON QUALITY OF SERVICE (IWQOS '98) SE International Workshop on Quality of Service LA English DT Proceedings Paper CT 1998 6th International Workshop on Quality of Service (IWQOS '98) CY MAY 18-20, 1998 CL NAPA, CA SP IEEE AB The current network architecture is based predominantly on stand-alone routers. It is becoming overtaxed with the introduction of integrated services. In this paper we propose a Server and Agent based Active network Management (SAAM) architecture that scales well with integrated services. SAAM relieves individual relaters from most routing and network management tasks. Instead, it employs a small number of dedicated servers to perform these tasks an behalf of the routers. In particular these sewers maintain a path information base (PIB), with which network functions, such as QoS routing and re-routing of real-time flows, can be efficiently implemented. We describe a scaleable architecture for organizing the servers as well as a concrete design of the PIE. SAAM has the potential of offering a common platform where multiple network functions - such as routing, resource reservation, network management accounting and security - can be integrated. C1 USN, Postgrad Sch, Dept Comp Sci, Monterey, CA 93943 USA. RP Xie, GG (reprint author), USN, Postgrad Sch, Dept Comp Sci, Monterey, CA 93943 USA. EM xie@cs.nps.navy.mil; hensgen@cs.nps.navy.mil; kidd@cs.nps.navy.mil; yarger@cs.nps.navy.mil 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 1548-615X BN 0-7803-4482-0 J9 INT WORKSH QUAL SERV PY 1998 BP 117 EP 126 DI 10.1109/IWQOS.1998.675228 PG 10 WC Computer Science, Information Systems; Engineering, Electrical & Electronic; Telecommunications SC Computer Science; Engineering; Telecommunications GA BL20N UT WOS:000074668000020 ER PT B AU Buss, A Jackson, L AF Buss, A Jackson, L BE Medeiros, DJ Watson, EF Carson, JS Manivannan, MS TI Distributed simulation modeling: A comparison of HLA, CORBA, and RMI 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 The execution of distributed simulations has become increasingly important to the Department of Defense (DOD). This paper compares three architectures for supporting distributed computing, HLA, CORBA, and RMI. While the fundamental structure of each is similar, there are differences that can profoundly impact an application developer or the administrator of a distributed simulation exercise. C1 USN, Postgrad Sch, Dept Operat Res, Monterey, CA 93943 USA. RP Buss, A (reprint author), USN, Postgrad Sch, Dept Operat Res, Monterey, CA 93943 USA. NR 7 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 819 EP 825 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:000078340100110 ER PT B AU Kang, K Gue, KR Eaton, DR AF Kang, K Gue, KR Eaton, DR BE Medeiros, DJ Watson, EF Carson, JS Manivannan, MS TI Cycle time reduction for naval aviation depots 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 describe two simulation models for repair processes of aircraft in the Navy, and suggest ways to reduce cycle time and improve readiness. The models illustrate the effects of material availability and process redesign on repair cycle time and work-in-process inventory levels for critical components. Our results indicate that the Navy could significantly reduce repair cycle times of those components by increasing stock levels of relatively inexpensive repair parts and slightly modifying current repair processes. C1 USN, Postgrad Sch, Dept Syst Management, Monterey, CA 93943 USA. RP Kang, K (reprint author), USN, Postgrad Sch, Dept Syst Management, Monterey, CA 93943 USA. NR 6 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 907 EP 912 PG 6 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:000078340100123 ER PT B AU Coleman, JE Smith, DR Malek-Madani, R AF Coleman, JE Smith, DR Malek-Madani, R GP AMER METEOROL SOC AMER METEOROL SOC AMER METEOROL SOC TI Serrin's vortex revisited SO 19TH CONFERENCE ON SEVERE LOCAL STORMS LA English DT Proceedings Paper CT 19th Conference on Severe Local Storms CY SEP 14-18, 1998 CL MINNEAPOLIS, MN SP Amer Meteorol Soc C1 USN Acad, Dept Oceanog, Annapolis, MD 21412 USA. RP Smith, DR (reprint author), USN Acad, Dept Oceanog, 572 Holloway Rd, Annapolis, MD 21412 USA. NR 10 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 72 EP 75 PG 4 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BM52X UT WOS:000079026500021 ER PT B AU Bowles, J Kappus, M Skibo, J Antoniades, J Davis, C AF Bowles, J Kappus, M Skibo, J Antoniades, J Davis, C BE Schaepman, M Schlapfer, D Itten, K TI Hyperspectral data compression and science algorithms for the NEMO satellite SO 1ST EARSEL WORKSHOP ON IMAGING SPECTROSCOPY LA English DT Proceedings Paper CT 1st EARSeL Workshop on Imaging Spectroscopy CY OCT 06-08, 1998 CL UNIV ZURICH, REMOTE SENSING LAB, ZURICH, SWITZERLAND SP EARSeL HO UNIV ZURICH, REMOTE SENSING LAB DE imaging spectrometry; real-time processing; compression; coastal ocean AB The Naval EarthMap Observer (NEMO) will carry a hyperspectral sensor to characterize the littoral environment for scientific studies and to meet Joint Naval needs. The sensor will measure 210 spectral channels over the range of 400 to 2500 nm. A 30 or 60 m GSD and a total crosstrack swath of 30 km will be used. The values of GSD and SNR will be sufficient to allow for long term monitoring and real-time characterization of the coastal environment. A unique feature of the spacecraft will be the on-board processing system which will allow for real time processing, feature extraction and data compression using the Optical Real-time Adaptive Spectral Identification System (ORASIS) algorithm. The ORASIS spectral processing system is based on linear spectral unmixing, which decomposes the observed spectrum of each pixel into a linear sum of the products of the spectra of the "pure" substances in the scene, termed the endmembers, multiplied by their respective abundances. It is non-statistical in nature. ORASIS compression is a variation of I,earned Vector Quantization (LVQ) that, while lossy, preferentially preserves the important spectral information. The compression allows for a data collection rates exceeding 60 GB/day. Because of the large data volumes, science algorithms being developed are designed to operate directly on the compressed data. Algorithms include those for atmospheric correction, bathymetry, water clarity, chlorophyll content, water hazards, etc. We demonstrate the effect of compression on the output of the ATREM code as well as general classification algorithms. C1 USN, Res Lab, REmote Sensing Div, Washington, DC 20375 USA. RP Bowles, J (reprint author), USN, Res Lab, REmote Sensing Div, Washington, DC 20375 USA. NR 6 TC 0 Z9 0 U1 0 U2 0 PU EUROPEAN ASSOC REMOTE SENSING LABORATORIES PI VERSAILLES PA LAB TELEDETECT INRA-INA PG, 78000 VERSAILLES, FRANCE BN 2-908885-22-0 PY 1998 BP 183 EP 190 PG 4 WC Remote Sensing; Spectroscopy SC Remote Sensing; Spectroscopy GA BR38E UT WOS:000166270600021 ER PT S AU Talmy, IG Zaykoski, JA Opeka, MA AF Talmy, IG Zaykoski, JA Opeka, MA BE Bray, D TI Properties of ceramics in the ZrB2/ZrC/SiC system prepared by reactive processing 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 AB Ceramics in the ZrB2 - ZrC - SiC system were prepared from mixtures of Zr (or ZrC), SiB4, and C using in-situ displacement reactions. Microstructure and oxidation behavior were characterized as a function of phase composition of the ceramics which was varied by changing the ratio of components in the reactant mixtures. The ceramics with ZrB2 as a predominant phase had high oxidation resistance up to 1500 degrees C compared to pure ZrB2 and ZrC ceramics. The ceramics with ZrB2/SiC molar ratio of 2 (25 vol. % SiC), containing little or no ZrC, was the most oxidation resistant up to 1500 degrees C. A model describing oxidation behavior of the ceramics is proposed. C1 USN, Ctr Surface Warfare, Carderock Div, W Bethesda, MD 20817 USA. RP Talmy, IG (reprint author), USN, Ctr Surface Warfare, Carderock Div, W Bethesda, MD 20817 USA. NR 0 TC 24 Z9 24 U1 0 U2 3 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 105 EP 112 PG 8 WC Materials Science, Ceramics; Materials Science, Characterization & Testing; Materials Science, Composites SC Materials Science GA BN01Q UT WOS:000080406200012 ER PT S AU Bender, BA Jessen, TL Browning, S AF Bender, BA Jessen, TL Browning, S BE Bray, D TI The effect of processing on the strength, thermal up shock resistance, and dielectric constant of Nicalon-reinforced zirconium phosphate 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 MATRIX COMPOSITES; FIBER; BEHAVIOR AB Three different ZrP2O7 matrix composite systems were made. The effects of processing (hot pressing versus phosphate bonding and three different grades of Nicalon SiC fiber) on strength, thermal up shock resistance, and dielectric constant were measured. The ZrP2O7 matrix composite reinforced with carbon-coated Hi-Nicalon SiC fibers had the best overall properties. C1 USN, Res Lab, Washington, DC 20375 USA. RP Bender, BA (reprint author), USN, Res Lab, Washington, DC 20375 USA. NR 13 TC 1 Z9 1 U1 0 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 121 EP 128 PG 8 WC Materials Science, Ceramics; Materials Science, Characterization & Testing; Materials Science, Composites SC Materials Science GA BN01Q UT WOS:000080406200014 ER PT S AU Jessen, TL Bender, BA Greenhut, VA AF Jessen, TL Bender, BA Greenhut, VA BE Bray, D TI Stress rate effects on the mechanical properties of CFCMCs as a function of microstructure 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 CERAMIC-MATRIX COMPOSITES; LOADING RATE; FATIGUE; GLASS AB The effect of five decades of constant cross-head displacement on the flexure strength and fracture behavior of a unidirectional fiber composite was investigated. The 50 volume percent Nicalon(TM) fiber/zirconium titanate matrix composite was similar to that used in an earlier study which demonstrated microstructure-sensitive mechanical behavior. In the present study, statistically significant differences in time-dependent strength were observed as a function of composite microstructure. Composite strength was independent of time-to-failure (TTF) when the composite contained distributed matrix-rich channels aligned perpendicular to the applied load. The strength was observed to decrease with increasing TTF when the matrix-rich channels were aligned parallel to the applied load. C1 USN, Res Lab, Washington, DC 20375 USA. RP Jessen, TL (reprint author), USN, Res Lab, Washington, DC 20375 USA. NR 12 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 3 BP 181 EP 188 PG 8 WC Materials Science, Ceramics; Materials Science, Characterization & Testing; Materials Science, Composites SC Materials Science GA BN01Q UT WOS:000080406200021 ER PT S AU Jessen, TL Rayne, RJ Bender, BA Flippen, LD Kim, C AF Jessen, TL Rayne, RJ Bender, BA Flippen, LD Kim, C BE Bray, D TI Joint integrity issues in a novel piezoceramic actuator design 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 High authority piezoceramic actuators incorporate joints in their design. These joints must be stiff to minimize actuation loss between piezoceramic elements yet pliable to survive high frequency cycling. Shear is the anticipated joint failure mode. The effects of joint finish and electrode material on shear strength mere evaluated for epoxy-joined piezoceramic specimens. No strength difference due to surface finish was noted for joints with electrodes. Different failure behavior was observed for joints with either air-dried Ag or sputter-deposited Au electrodes, FEM code was developed to model joint performance as a function of constituents, thickness, and shape. C1 USN, Res Lab, Washington, DC 20375 USA. RP Jessen, TL (reprint author), USN, Res Lab, Washington, DC 20375 USA. NR 4 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 233 EP 240 PG 8 WC Materials Science, Ceramics; Materials Science, Composites SC Materials Science GA BN01R UT WOS:000080406400026 ER PT S AU Jessen, TL Kee, A AF Jessen, TL Kee, A BE Bray, D TI Rudimentary CFCMC design and mechanical behavior prediction 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 ID SILICON-CARBIDE FIBER; STRENGTH AB The effect of fiber distribution on the mechanical behavior of unidirectional fiber composites has been previously established. Using Controlled Structure Technology (CST), a process by which the fiber distribution within the microstructure can be engineered, a series of unidirectional fiber composites were prepared. The mechanical behavior of the CST composites were compared to that of conventionally prepared specimens. In conjunction with the mechanical testing, finite element methods (FEM) were employed to simulate crack propagation through actual digitized microstructures. The FEM simulations allow investigation of a variety of loading conditions for a given engineered microstructure in a cost-effective manner. Combining the ability to engineer microstructures via CST with application-specific stress simulation may allow faster assimilation of ceramic fiber composites as structural materials, paper reports the preliminary mechanical behavior and simulation results for CST composites which show superior performance to conventionally prepared composites. C1 USN, Res Lab, Washington, DC 20375 USA. RP Jessen, TL (reprint author), USN, Res Lab, Washington, DC 20375 USA. NR 8 TC 2 Z9 2 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 265 EP 272 PG 8 WC Materials Science, Ceramics; Materials Science, Composites SC Materials Science GA BN01R UT WOS:000080406400030 ER PT S AU Reed, LE AF Reed, LE GP IEEE IEEE IEEE TI Performing a literature review SO 28TH ANNUAL FRONTIERS IN EDUCATION CONFERENCE - CONFERENCE PROCEEDINGS, VOLS 1-3 SE PROCEEDINGS-FRONTIERS IN EDUCATION CONFERENCE LA English DT Proceedings Paper CT 28th Annual Frontiers in Education Conference on Moving from Teacher-Centered to Learner-Centered Education CY NOV 04-07, 1998 CL TEMPE, AZ SP IEEE, Educ Soc, IEEE, Comp Soc, ASEE, Educ Res & Methods Div AB This report is intended as a guide for teachers and engineering students when conducting research is part of course-work requirements. Discussion includes a description of a literature search, the purpose of a literature review, finding sources (especially for engineering), and a general strategy to help conduct an efficient and productive literature search. Using tools such as this report, students can become more pro-active about their research projects. Teachers can use this report, among other tools, to begin dialog with their students about expectations for research assignments. Two key steps in a literature search are i) finding sources and ii) synthesizing information. Each of these is addressed in two of the major sections in this report, as well as how the literature search relates to the entire research process. Then pertinent information is repeated in the summary section for your convenience. An annotated reference list is included for ease in finding other useful guidance. C1 USN, Syst Engn Div, Air Warfare Ctr Weapons Div, China Lake, CA 93555 USA. RP Reed, LE (reprint author), USN, Syst Engn Div, Air Warfare Ctr Weapons Div, China Lake, CA 93555 USA. NR 0 TC 0 Z9 0 U1 1 U2 3 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0190-5848 BN 0-7803-4762-5 J9 PROC FRONT EDUC CONF PY 1998 BP 380 EP 383 PG 4 WC Computer Science, Interdisciplinary Applications; Education, Scientific Disciplines; Engineering, Multidisciplinary SC Computer Science; Education & Educational Research; Engineering GA BM16D UT WOS:000077858200090 ER PT S AU Wick, CE Piper, GE AF Wick, CE Piper, GE GP IEEE IEEE IEEE TI Using the ADSP-21061 SHARC EZ-KIT in undergraduate DSP oriented courses SO 28TH ANNUAL FRONTIERS IN EDUCATION CONFERENCE - CONFERENCE PROCEEDINGS, VOLS 1-3 SE PROCEEDINGS-FRONTIERS IN EDUCATION CONFERENCE LA English DT Proceedings Paper CT 28th Annual Frontiers in Education Conference on Moving from Teacher-Centered to Learner-Centered Education CY NOV 04-07, 1998 CL TEMPE, AZ SP IEEE, Educ Soc, IEEE, Comp Soc, ASEE, Educ Res & Methods Div AB In this paper we discuss the use of Analog Devices ADSP-21061 SHARC EZ-KIT evaluation board as a teaching tool. We have developed a Windows-95 "front-end" program to accompany the evaluation board that ties Analog Devices' C programming package with some additional editing, downloading, uploading and graphing tools. The complete package provides much improved access to program development fools and to the processor for program operation, debugging and data extraction. With this set of programs, we believe that this processor and evaluation board can now become an effective tool for exploring the use of digital processors for signal processing and for control applications by students who have little computer science background. In this paper we present an example laboratory exercise using these tools. C1 USN Acad, Dept Weapon & Syst Engn, Annapolis, MD 21402 USA. RP Wick, CE (reprint author), USN Acad, Dept Weapon & Syst Engn, 105 Maryland Ave, Annapolis, MD 21402 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 0190-5848 BN 0-7803-4762-5 J9 PROC FRONT EDUC CONF PY 1998 BP 691 EP 694 PG 4 WC Computer Science, Interdisciplinary Applications; Education, Scientific Disciplines; Engineering, Multidisciplinary SC Computer Science; Education & Educational Research; Engineering GA BM16D UT WOS:000077858200166 ER PT S AU Avramov-Zamurovic, S Wick, C Dwan, T AF Avramov-Zamurovic, S Wick, C Dwan, T GP IEEE IEEE IEEE TI Communications track for systems engineering majors SO 28TH ANNUAL FRONTIERS IN EDUCATION CONFERENCE - CONFERENCE PROCEEDINGS, VOLS 1-3 SE PROCEEDINGS-FRONTIERS IN EDUCATION CONFERENCE LA English DT Proceedings Paper CT 28th Annual Frontiers in Education Conference on Moving from Teacher-Centered to Learner-Centered Education CY NOV 04-07, 1998 CL TEMPE, AZ SP IEEE, Educ Soc, IEEE, Comp Soc, ASEE, Educ Res & Methods Div AB The Weapons and Systems Engineering Department at the United States Naval Academy offers an undergraduate degree in Systems Engineering (Controls) to approximately 100 midshipmen annually. Fourth year students are allowed to specialize by taking a two-course track chosen from several areas of interest. Our communications track is one of these areas. The communication track integrates signal analysis and processing methods, and modern communication systems operation principles through hands-on laboratory experience and computer simulation. The uniqueness of this track is that it is offered to students that do not have traditional electrical engineering background. The paper will detail our experience in teaching modern communication systems to undergraduate Systems Engineering majors. C1 USN Acad, Weapons & Syst Engn Dept, Annapolis, MD 21402 USA. RP Avramov-Zamurovic, S (reprint author), USN Acad, Weapons & Syst Engn Dept, Annapolis, MD 21402 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 0190-5848 BN 0-7803-4762-5 J9 PROC FRONT EDUC CONF PY 1998 BP 949 EP 952 PG 4 WC Computer Science, Interdisciplinary Applications; Education, Scientific Disciplines; Engineering, Multidisciplinary SC Computer Science; Education & Educational Research; Engineering GA BM16D UT WOS:000077858200230 ER PT S AU Wooten, EC AF Wooten, EC GP IEEE IEEE IEEE TI Cooperative learning: Introduced in three different levels of electrical engineering courses at a military institution SO 28TH ANNUAL FRONTIERS IN EDUCATION CONFERENCE - CONFERENCE PROCEEDINGS, VOLS 1-3 SE PROCEEDINGS-FRONTIERS IN EDUCATION CONFERENCE LA English DT Proceedings Paper CT 28th Annual Frontiers in Education Conference on Moving from Teacher-Centered to Learner-Centered Education CY NOV 04-07, 1998 CL TEMPE, AZ SP IEEE, Educ Soc, IEEE, Comp Soc, ASEE, Educ Res & Methods Div AB Cooperative learning and group work should be prime teaching styles and methods for the U.S. Naval Academy (USNA). For one thing, the students, midshipmen, are all housed in a single dormitory. They have easy access to each other for group homework and group studying, and most of them have commitments to be on campus nightly (Sunday Friday), as well as most weekends throughout the semester. Also, the midshipmen are formally trained in leadership roles and team management throughout their four years, as part of their military requirement So the assignment of leadership roles in group learning and their cooperative efforts should come naturally. Therefore, a comprehensive effort to introduce many aspects of cooperative learning was attempted in three different levels of electrical engineering (E.E.) courses for juniors at the USNA this academic year (97-98). The Naval Academy requires every midshipman to take an E.E. course, to familiarize each oft hem with the technical terms and basic electrical systems that they may encounter in the fleet. One level of the courses was taught to the Humanities majors, one level was taught to the Engineering majors, and another level was taught to the Electrical Engineering majors. This paper addresses the advantages and disadvantages of the new cooperative teaching methods, which were implemented to these three different classes of students. Richard M. Felder and Rebecca Brent introduced these learning styles to the USNA in the beginning of the fall semester in an inspiring "Effective Teaching Workshop". A discussion is provided on how the methods matched the different classes, and on how they were assessed by the students and the professor. C1 USN Acad, Dept Elect Engn, Annapolis, MD 21402 USA. RP Wooten, EC (reprint author), USN Acad, Dept Elect Engn, Annapolis, MD 21402 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 0190-5848 BN 0-7803-4762-5 J9 PROC FRONT EDUC CONF PY 1998 BP 1179 EP 1184 PG 6 WC Computer Science, Interdisciplinary Applications; Education, Scientific Disciplines; Engineering, Multidisciplinary SC Computer Science; Education & Educational Research; Engineering GA BM16D UT WOS:000077858200291 ER PT B AU Davis, AJ Fischer, G AF Davis, AJ Fischer, G GP IEEE TI A MASH modulator with digital correction for amplifier finite gain effects and C-ratio matching errors SO 40TH MIDWEST SYMPOSIUM ON CIRCUITS AND SYSTEMS, VOLS 1 AND 2 LA English DT Proceedings Paper CT 40th Midwest Symposium on Circuits and Systems CY AUG 03-06, 1997 CL SACRAMENTO, CA SP Univ Calif Davis, Elect & Comp Engn Dept, IEEE, Circuits & Syst Soc AB An alternative approach to remove the effects of amplifier finite gain and C-ratio mismatches encountered in a MASH delta-sigma modulator is presented. By adding a digital correction term to the output of the digital noise cancelation filter, the parasitic quantization noise terms can be removed for all but the final stage, eliminating the lower-order quantization noise terms due to non-ideal integrators. Using this technique, the MASH can approach the performance of an ideal 3(rd) order modulator. We have confirmed an SNR+THD of 105.6dB via a behavioral simulation of the MASH using an amplifier open-loop gain of only 500 and capacitor matching errors as large as of 1.0 %. C1 USN, Undersea Warfare Ctr, Weapon Syst Dept, Newport, RI 02841 USA. RP Davis, AJ (reprint author), USN, Undersea Warfare Ctr, Weapon Syst Dept, Newport, RI 02841 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 0-7803-3694-1 PY 1998 BP 221 EP 224 PG 4 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Computer Science, Information Systems; Engineering, Electrical & Electronic SC Automation & Control Systems; Computer Science; Engineering GA BK71E UT WOS:000073160900055 ER PT B AU Barton, RJ Walker, TO Fouts, DJ AF Barton, RJ Walker, TO Fouts, DJ GP IEEE TI A CMOS current-mode full-adder cell for multi-valued logic VLSI SO 40TH MIDWEST SYMPOSIUM ON CIRCUITS AND SYSTEMS, VOLS 1 AND 2 LA English DT Proceedings Paper CT 40th Midwest Symposium on Circuits and Systems CY AUG 03-06, 1997 CL SACRAMENTO, CA SP Univ Calif Davis, Elect & Comp Engn Dept, IEEE, Circuits & Syst Soc AB This paper describes the design and implementation of a carry save adder cell for multi-valued logic (modulo 4) VLSI using the HAMLET CAD tool [1]. A VLSI test and evaluation integrated circuit was implemented with MAGIC, simulated using SPICE, and fabricated through the MOSIS service. Engineering modifications to the original current-mode inverter cells used by HAMLET were made leading to significant power savings in a complete design. The fabricated device performed as predicted by SPICE simulation. C1 USN, Postgrad Sch, Dept Elect & Comp Engn, Monterey, CA 93943 USA. RP Barton, RJ (reprint author), USN, Postgrad Sch, Dept Elect & Comp Engn, Monterey, CA 93943 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 0-7803-3694-1 PY 1998 BP 463 EP 467 PG 3 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Computer Science, Information Systems; Engineering, Electrical & Electronic SC Automation & Control Systems; Computer Science; Engineering GA BK71E UT WOS:000073160900116 ER PT B AU McEachen, JC Nehorai, A Duncan, JS AF McEachen, JC Nehorai, A Duncan, JS GP IEEE TI Temporal estimation of cardiac non-rigid motion in image sequences SO 40TH MIDWEST SYMPOSIUM ON CIRCUITS AND SYSTEMS, VOLS 1 AND 2 LA English DT Proceedings Paper CT 40th Midwest Symposium on Circuits and Systems CY AUG 03-06, 1997 CL SACRAMENTO, CA SP Univ Calif Davis, Elect & Comp Engn Dept, IEEE, Circuits & Syst Soc AB A robust, flexible system for tracking the point to point non-rigid motion in image sequences has been developed. This system is unique in its ability to model motion across multiple frames. The motivating application is tracking the non-rigid, non-unifrom motion of the left ventricular (LV) wall of the heart. The foundation of this system is an adaptive transversal filter based on the recursive least-squares algorithm which facilitates the integration of models for periodicity and proximal smoothness as appropriate using a contour-based description of the object's boundaries. C1 USN, Postgrad Sch, Dept Elect & Comp Engn, Monterey, CA 93943 USA. RP McEachen, JC (reprint author), USN, Postgrad Sch, Dept Elect & Comp Engn, Monterey, CA 93943 USA. RI Nehorai, Arye/G-1661-2011 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 0-7803-3694-1 PY 1998 BP 901 EP 904 PG 4 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Computer Science, Information Systems; Engineering, Electrical & Electronic SC Automation & Control Systems; Computer Science; Engineering GA BK71E UT WOS:000073160900224 ER PT B AU Fargues, MP Barsanti, RJ Hippenstiel, R Coutu, G AF Fargues, MP Barsanti, RJ Hippenstiel, R Coutu, G GP IEEE TI Wavelet-based denoising: Comparisons between orthogonal and non-orthogonal decompositions SO 40TH MIDWEST SYMPOSIUM ON CIRCUITS AND SYSTEMS, VOLS 1 AND 2 LA English DT Proceedings Paper CT 40th Midwest Symposium on Circuits and Systems CY AUG 03-06, 1997 CL SACRAMENTO, CA SP Univ Calif Davis, Elect & Comp Engn Dept, IEEE, Circuits & Syst Soc AB In this study we present a denoising scheme applied to a non-orthogonal wavelet transform and compare the performances obtained with those based on orthogonal decompositions. We investigate the effect due to small sample sizes, specific thresholding levels, and initial thresholding scales, and compare results obtained for orthogonal and non-orthogonal transforms. C1 USN, Postgrad Sch, Dept Elect & Comp Engn, Monterey, CA 93943 USA. RP Fargues, MP (reprint author), USN, Postgrad Sch, Dept Elect & Comp Engn, Monterey, CA 93943 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 0-7803-3694-1 PY 1998 BP 929 EP 932 PG 4 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Computer Science, Information Systems; Engineering, Electrical & Electronic SC Automation & Control Systems; Computer Science; Engineering GA BK71E UT WOS:000073160900231 ER PT B AU Tummala, M Midwood, SA Glenn, IN AF Tummala, M Midwood, SA Glenn, IN GP IEEE TI Multisensor data fusion using fuzzy-association techniques SO 40TH MIDWEST SYMPOSIUM ON CIRCUITS AND SYSTEMS, VOLS 1 AND 2 LA English DT Proceedings Paper CT 40th Midwest Symposium on Circuits and Systems CY AUG 03-06, 1997 CL SACRAMENTO, CA SP Univ Calif Davis, Elect & Comp Engn Dept, IEEE, Circuits & Syst Soc AB This paper describes the development of an algorithm to fuse redundant observations due to multiple sensor coverage of a vessel within the Vessel Traffic Services (VTS) system. Fuzzy membership functions are used as a measure of correlation, and a fuzzy associative system determines which observations represent the same vessel. The result is a computationally efficient algorithm. The output of the system is a unique set of vessels identified by unique platform identifiers. Results of tests based on computer simulation of overlapping radar coverage show that the fusion algorithm correctly correlates and fuses the sensor observations. C1 USN, Postgrad Sch, Dept Elect & Comp Engn, Monterey, CA 93943 USA. RP Tummala, M (reprint author), USN, Postgrad Sch, Dept Elect & Comp Engn, Monterey, CA 93943 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 0-7803-3694-1 PY 1998 BP 953 EP 956 PG 4 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Computer Science, Information Systems; Engineering, Electrical & Electronic SC Automation & Control Systems; Computer Science; Engineering GA BK71E UT WOS:000073160900237 ER PT B AU Shehata, KA Fouts, DJ Michael, S AF Shehata, KA Fouts, DJ Michael, S GP IEEE TI A dynamic four-bit carry lookahead adder circuit for Complementary Gallium Arsenide (CGaAs) fabrication processes SO 40TH MIDWEST SYMPOSIUM ON CIRCUITS AND SYSTEMS, VOLS 1 AND 2 LA English DT Proceedings Paper CT 40th Midwest Symposium on Circuits and Systems CY AUG 03-06, 1997 CL SACRAMENTO, CA SP Univ Calif Davis, Elect & Comp Engn Dept, IEEE, Circuits & Syst Soc AB The design and implementation of three, 4-bit carry lookahead adders using Complementary Gallium Arsenide (CGaAs) HIGFETs is presented, including static, pipelined static and dynamic versions. The designs are compared for speed, power consumption and layout area. The dynamic implementation operates at the highest speed (1.2 GHz) and consumes the best power (0.01 mu W/MHz/gate). C1 USN, Postgrad Sch, Dept Elect & Comp Engn, Monterey, CA 93943 USA. RP Shehata, KA (reprint author), USN, Postgrad Sch, Dept Elect & Comp Engn, Monterey, CA 93943 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 0-7803-3694-1 PY 1998 BP 1103 EP 1106 PG 4 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Computer Science, Information Systems; Engineering, Electrical & Electronic SC Automation & Control Systems; Computer Science; Engineering GA BK71E UT WOS:000073160900274 ER PT B AU Fouts, DJ Shehata, KA Michael, S AF Fouts, DJ Shehata, KA Michael, S GP IEEE TI Dynamic logic families for complementary gallium arsenide (CGaAs) fabrication processes SO 40TH MIDWEST SYMPOSIUM ON CIRCUITS AND SYSTEMS, VOLS 1 AND 2 LA English DT Proceedings Paper CT 40th Midwest Symposium on Circuits and Systems CY AUG 03-06, 1997 CL SACRAMENTO, CA SP Univ Calif Davis, Elect & Comp Engn Dept, IEEE, Circuits & Syst Soc AB Different Complementary Gallium Arsenide (CGaAs) dynamic logic circuits have been designed, simulated and implemented. The circuits include Domino, N-P Domino, and Two-Phase Dynamic FET Logic (TPDL). These circuits are investigated and compared against complementary static logic for speed, power consumption and layout area. TPDL circuits are the fastest (function properly up to 2.38 GHz) and have the lowest power consumption ever reported in this technology (0.01 mu W/MHz/gate). Moreover, TPDL circuits are self latching and well suited for pipelined architectures. C1 USN, Postgrad Sch, Dept Elect & Comp Engn, Monterey, CA 93943 USA. RP Fouts, DJ (reprint author), USN, Postgrad Sch, Dept Elect & Comp Engn, Monterey, CA 93943 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 0-7803-3694-1 PY 1998 BP 1107 EP 1110 PG 4 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Computer Science, Information Systems; Engineering, Electrical & Electronic SC Automation & Control Systems; Computer Science; Engineering GA BK71E UT WOS:000073160900275 ER PT B AU Weatherford, TR Fouts, DJ Marshall, PW Marshall, CJ Dietrich, H AF Weatherford, TR Fouts, DJ Marshall, PW Marshall, CJ Dietrich, H GP IEEE TI Soft error immune GaAs circuit technologies SO 40TH MIDWEST SYMPOSIUM ON CIRCUITS AND SYSTEMS, VOLS 1 AND 2 LA English DT Proceedings Paper CT 40th Midwest Symposium on Circuits and Systems CY AUG 03-06, 1997 CL SACRAMENTO, CA SP Univ Calif Davis, Elect & Comp Engn Dept, IEEE, Circuits & Syst Soc AB Cosmic radiation induced soft errors present a major difficulty for space applications that utilize digital GaAs circuits and systems. Techniques to reduce soft error sensitivity by 5 orders of magnitude or more, to sufficient levels for safe implemention of GaAs ICs in space applications are presented. These results show that the need for redundancy and error correction is eliminated. Space systems will benefit by reduced power and area requirements, plus a substantial improvement in system performance over present radiation hardened silicon-based technologies. C1 USN, Postgrad Sch, Monterey, CA 93940 USA. RP Weatherford, TR (reprint author), USN, Postgrad Sch, Monterey, CA 93940 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 0-7803-3694-1 PY 1998 BP 1116 EP 1119 PG 2 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Computer Science, Information Systems; Engineering, Electrical & Electronic SC Automation & Control Systems; Computer Science; Engineering GA BK71E UT WOS:000073160900277 ER PT B AU Sorathia, U Ness, J Blum, M AF Sorathia, U Ness, J Blum, M BE Kliger, HS Rasmussen, BM Pilato, LA Tolle, TB TI Fire safety of composites in the US Navy 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 low smoke composites; vinyl esters; fire retardants AB Composite materials for marine applications offer the benefit of weight savings, corrosion resistance, and reduced life cycle costs. The composite structures used in marine applications tend to be large, complex, and thick. As such, the use of low temperature non-autoclave cure resins is desirable. The U.S. Navy is presently using fire retarded (brominated) vinyl ester resin for some topside composite structures. These composites are produced by vacuum assisted resin transfer molding. Brominated vinyl ester resin generates dense heavy smoke with high yields of carbon monoxide. Acid gases such as hydrogen bromide are also produced. Several alternative resins with and without non halogenated fire retardants have been recently evaluated by NSWCCD in small scale fire test methods. These included cone calorimeter testing at three different fluxes of 25, 50, and 75 kW/m(2). The summary of results, including smoke production rate and carbon monoxide yield, is presented for different vinyl ester resins with and without additives. Brominated epoxy vinyl ester marked #1168 exhibited lower heat release rates, but significantly higher smoke generation and CO yield when compared with non brominated vinyl esters. Of the additives studied, aluminum trihydrate (15 phr, #1196) shows 20 and 25% decrease in peak heat release rates, 24 and 13% decrease in average heat release rates, and 27 and 24% decrease in average mass loss rates at radiant heat fluxes of 50 and 75 kW/m(2) respectively. C1 USN, Ctr Surface Warfare, Carderock Div, Bethesda, MD 20817 USA. RP Sorathia, U (reprint author), USN, Ctr Surface Warfare, Carderock Div, Bethesda, MD 20817 USA. NR 0 TC 0 Z9 0 U1 1 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 1067 EP 1076 PG 10 WC Materials Science, Multidisciplinary; Materials Science, Characterization & Testing; Materials Science, Composites; Polymer Science SC Materials Science; Polymer Science GA BL49K UT WOS:000075698500100 ER PT B AU Mechtel, DM Charles, HK Francomacaro, AS AF Mechtel, DM Charles, HK Francomacaro, AS GP EIA EIA TI MCM structures with poled dielectrics to improve testability SO 48TH ELECTRONIC COMPONENTS & TECHNOLOGY CONFERENCE - 1998 PROCEEDINGS SE PROCEEDINGS - ELECTRONIC COMPONENTS AND TECHNOLOGY CONFERENCE LA English DT Proceedings Paper CT 48th Electronic Components & Technology Conference CY MAY 25-28, 1998 CL SEATTLE, WA SP IEEE, Components Packaging Mfg Technol Soc, Electr Ind Assoc AB To improve multichip module (MCM) testability, we have used a new, recently-demonstrated technique to detect on-substrate electric field strength. This technique employs a noninvasive, laser-based instrument to probe MCM structures fabricated with poled polyimide interlayer dielectrics and thin film metallizations on silicon carriers. Circuit elements characteristic of MCMs were probed to detect electric field strength. The electrical, mechanical, and optical properties of these electro-optic dielectric layers were determined to investigate the effect of the poling and processing operations on the efficacy of the polyimide as both a dielectric layer and an electro-optic material suitable for laser probing. C1 USN Acad, Annapolis, MD 21401 USA. RP Mechtel, DM (reprint author), USN Acad, 105 Maryland Ave, Annapolis, MD 21401 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 0-7803-4526-6 J9 P ELECTR C PY 1998 BP 1286 EP 1290 DI 10.1109/ECTC.1998.678907 PG 5 WC Engineering, Electrical & Electronic SC Engineering GA BL14K UT WOS:000074438800203 ER PT S AU Rice, TR Alouani, AT AF Rice, TR Alouani, AT BE Masten, MK Stockum, LA TI Multiple model filtering SO ACQUISITION, TRACKING, AND POINTING XII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Acquisition, Pointing, and Tracking CY APR 15-16, 1998 CL ORLANDO, FL SP SPIE AB This paper investigates the existence and design of optimal, multiple model filters for target tracking using different local models. Two models are used: a Constant Velocity (CV) and a Constant Acceleration (CA) model. Sufficient conditions are derived that guarantee the existence of optimal multiple model filters. The problem is then solved for the case where the switching gains are diagonal matrices. The performance of the derived multiple model filter is evaluated using a simulated target trajectory. C1 USN, Ctr Surface Warfare, Syst Res & Technol Dept, Dahlgren Div, Dahlgren, VA 22448 USA. RP Rice, TR (reprint author), USN, Ctr Surface Warfare, Syst Res & Technol Dept, Dahlgren Div, Dahlgren, VA 22448 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 0-8194-2814-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3365 BP 100 EP 112 DI 10.1117/12.317501 PG 13 WC Engineering, Aerospace; Optics SC Engineering; Optics GA BL55F UT WOS:000075850600011 ER PT S AU Watson, GA Anthony, KS AF Watson, GA Anthony, KS BE Masten, MK Stockum, LA TI Improved tracking of unresolved targets by an ESA with the inclusion of an IRST SO ACQUISITION, TRACKING, AND POINTING XII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Acquisition, Pointing, and Tracking CY APR 15-16, 1998 CL ORLANDO, FL SP SPIE DE tracking; IRST; Electronically Scanned Array; unresolved targets AB The measurements for two targets will be merged when the targets are closely-spaced with respect to the resolution of the radar. Improved monopulse processing techniques for an Electronically Scanned Array (ESA) can be used to compute a measurement for each target and used to update the state estimates. However, a substantial amount of radar resources is required to perform this operation. The integration of the ESA with additional sensors has the potential to enhance the tracking and reduce the resource allocation requirements of the ESA when targets are unresolved. A complementary sensor would provide measurements for both targets and can be employed to form a composite track for the ESA. The tracks will not be merged and the ESA can better utilize its resources. This paper presents algorithms for the tracking of maneuvering targets and multisensor integration for effective ESA resource management when tracking unresolved targets. The sensor suite includes an ESA and an Infrared Search and Track (IRST) sensor. The effect of sensor integration on tracking performance and ESA resource allocation will be presented for single and multiple sensor configurations. C1 USN, Ctr Surface Warfare, Digital Syst Branch, Syst Res & Technol Dept,Dahlgren Div, Dahlgren, VA 22448 USA. RP Watson, GA (reprint author), USN, Ctr Surface Warfare, Digital Syst Branch, Syst Res & Technol Dept,Dahlgren Div, Code B32, Dahlgren, VA 22448 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 0-8194-2814-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3365 BP 119 EP 130 DI 10.1117/12.317503 PG 12 WC Engineering, Aerospace; Optics SC Engineering; Optics GA BL55F UT WOS:000075850600013 ER PT J AU Murawski, K Boice, DC Huebner, WF DeVore, CR AF Murawski, K Boice, DC Huebner, WF DeVore, CR TI Two-dimensional MHD simulations of the solar wind interaction with Comet Halley SO ACTA ASTRONOMICA LA English DT Article DE solar wind; magnetohydrodynamics (MHD); comets : individual : Halley ID FLUX-CORRECTED TRANSPORT; NUMERICAL SIMULATIONS; MAGNETIC-FIELD; PLASMA; ALGORITHMS; MODEL; VENUS AB Numerical simulations are performed in the framework of nonlinear two-dimensional magnetohydrodynamics to investigate the solar wind interaction with Comet Halley at 0.83 a.u. corresponding to the Vega 2 encounter. The governing equations are solved by a flux corrected transport method. For a gas (water) production rate of 10(30) molecules/sec, it was found that a weak bow shock is formed at about 0.5 million km upstream the comet nucleus while a contact surface and an inner shock are located at about 20 000 km in the subsolar direction from the nucleus. We also found an enhancement of the ion-mass density just inside the contact surface, at the position of the inner shock. The model reasonably reproduced the locations of the bow shock and the diamagnetic cavity that were observed by recent missions to Comet Halley. C1 Tech Univ Lublin, Div Environm Studies, PL-20618 Lublin, Poland. SW Res Inst, Dept Space Sci, San Antonio, TX USA. USN, Res Lab, Computat Phys & Fluid Dynam Lab, Washington, DC 20375 USA. RP Tech Univ Lublin, Div Environm Studies, Nadbystrzycka 40, PL-20618 Lublin, Poland. EM kamur@akropolis.pol.lublin.pl RI DeVore, C/A-6067-2015 OI DeVore, C/0000-0002-4668-591X NR 27 TC 5 Z9 5 U1 0 U2 1 PU COPERNICUS FOUNDATION POLISH ASTRONOMY PI WARSAW PA AL UJAZDOWSKIE 4, 00-478 WARSAW, POLAND SN 0001-5237 J9 ACTA ASTRONOM JI Acta Astron. PY 1998 VL 48 IS 4 BP 803 EP 817 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 161WB UT WOS:000078311700013 ER PT B AU Chiang, J Dermer, CD AF Chiang, J Dermer, CD BE Scarsi, L Bradt, H Giommi, P Fiore, F TI Gamma-ray burst afterglows from decelerating material: Blast waves and plasmoids SO ACTIVE X-RAY SKY: RESULTS FROM BEPPOSAX AND RXTE LA English DT Proceedings Paper CT Active X-Ray Sky Conference CY OCT 21-24, 1997 CL ROME, ITALY AB We examine the dynamics and emitted radiation from material with a large initial bulk Lorentz, factor which decelerates as it sweeps up ambient matter. The bulk kinetic energy of the material is converted into non-thermal energy of electrons which radiate isotropically in the locally co-moving frame. Self-consistent solutions for the dynamics of the material are computed which account for changes in its bulk relativistic inertia due to accretion and the emitted radiation. Fully radiative and non-radiative solutions are shown to be limiting cases agreeing with standard solutions for spherically expanding blast waves. We have calculated the afterglow synchrotron emission for a variety of parameters and geometries, and we compare a fiducial example to the afterglow behavior observed from recent gamma-ray burst X-ray and optical couterparts. C1 USN, Res Lab, Washington, DC 20375 USA. RP Chiang, J (reprint author), USN, Res Lab, 4555 Overlook Ave SW, Washington, DC 20375 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA SARA BURGERHARTSTRAAT 25, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS BN 0-444-82990-3 PY 1998 BP 699 EP 702 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BL61F UT WOS:000076009100135 ER PT S AU Root, B AF Root, B BE Luk, FT TI High-frequency over-the-horizon radar ship detection through clutter cancellation: an alternative to high-resolution spectral estimation 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 spectral estimation; high-resolution; superresolution; clutter cancellation; target identification AB High-resolution (or superresolution) spectral estimation is the resolution of spectral components that cannot be distinguished in the Fourier transform. This paper presents what is, in effect, an unusual technique to perform high-resolution spectral estimation. By canceling powerful and obscuring ocean clutter, weak ship targets are exposed in the short-time Fourier transform of a particular kind of radar data. This achieves the same result as high-resolution spectral estimation, but it also preserves the desirable properties of the Fourier transform. A specific clutter-canceling algorithm has been developed and successfully tested on data from the U.S. Navy's Relocatable Over-the-Horizon Radar(ROTHR). A side-by-side comparison of this algorithm with Tufts-Kumerisan forward-backward linear prediction, a popular high-resolution spectral estimator, will be presented. Although both techniques performed well at detecting the ship and estimating its Doppler frequency, the clutter cancellation technique seems to provide a better estimate of the ship power relative to the peak of the clutter. This property would be useful in target identification. C1 USN, Res Lab, Div Radar, Washington, DC 20375 USA. RP Root, B (reprint author), USN, Res Lab, Div Radar, Washington, DC 20375 USA. NR 0 TC 3 Z9 3 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 488 EP 500 DI 10.1117/12.325708 PG 13 WC Engineering, Electrical & Electronic SC Engineering GA BL81C UT WOS:000076796000047 ER PT S AU Kassim, NE Erickson, WC AF Kassim, NE Erickson, WC BE Phillips, TG TI Meter/Decameter wavelength array for astrophysics and solar radar SO ADVANCED TECHNOLOGY MMW, RADIO, AND TERAHERTZ TELESCOPES SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Advanced Technology MMW, Radio, and Terahertz Telescopes CY MAR 26-28, 1998 CL KONA, HI SP SPIE, European So Observ DE radio interferometry; nonthermal emission; thermal absorption; low-frequency instrumentation; solar radar AB We present the scientific motivation and design for a Long Wavelength Array (LWA) to open a new, high resolution window on the electromagnetic spectrum from 15-150 MHz. This region has been poorly explored because ionospheric turbulence has limited imaging to very course angular resolution. New phase compensation techniques now make it possible to explore this region at unprecedented angular resolution. We describe a large (>100 km), completely electronic instrument capable of imaging radio sources across the sky and spectrum rapidly, but which could be built at a fraction of the cost of higher frequency systems of comparable size or sophistication. The LWA will be a powerful instrument for delineating the interaction between nonthermal emitting plasmas and thermal absorbing gas, for differentiating between self-absorption processes, and for exploring the universe for coherent emission processes. For both Galactic and extragalactic work it will provide unique information an the distribution of ionized gas, relativistic particles, and magnetic fields. For solar physics the LWA will be the ideal solar radar receiver and can be used to image Earth-ward bound Coronal Mass Ejections for accurate geomagnetic storm prediction. C1 USN, Res Lab, Washington, DC 20375 USA. RP Kassim, NE (reprint author), USN, Res Lab, Code 7213, Washington, DC 20375 USA. NR 0 TC 14 Z9 14 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 0-8194-2804-3 J9 P SOC PHOTO-OPT INS PY 1998 VL 3357 BP 740 EP 754 DI 10.1117/12.317406 PG 15 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BL55D UT WOS:000075850400077 ER PT S AU Wolk, M McGillicuddy, RJ Zurlinden, JE AF Wolk, M McGillicuddy, RJ Zurlinden, JE BE Stepp, LM TI Conjugate cassegrain telescopes for thermal source FTIR spectral radiometric calibration SO ADVANCED TECHNOLOGY OPTICAL/IR TELESCOPES VI SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Advanced Technology Optical/IR Telescopes VI CY MAR 23-25, 1998 CL KONA, HI SP SPIE, European SO Observ DE telescope; Cassegrain; FTIR; radiometric; calibration; non-contact thermometry AB Two Cassegrain telescopes were constructed to function as sender and receiver for an FTIR spectrometer primarily for the purpose of obtaining spectral data for analysis of military night vision emission targets, and spectral calibration of external variable temperature thermal radiation sources, utilizing freezing-point type blackbodies for primary radiation temperature standards. The sender and receiver telescopes, F/7 and F/5, respectively, each employ 0.30 m (12 in) diameter primary and 0.15 m (6 in) diameter secondary, protected Ag coated Zerodur mirrors. In operation, a thermal target image formed by the sender, whose optical axis is aligned with that of the receiver and spectrometer, is transmitted to and brought to a focus at the spectrometer entrance aperture by the receiver telescope. With lambda/8 p-v optical surface accuracy at 633 nm, telescope system rests indicate near diffraction-limited performance in the visible, and 2.81 mad (full) FOV with further reduction achieved with field stops. Wavelength range capability of the commercially available FTIR instrument employed is approximately 0.22 mu m (55000 cm(-1)) to 22 mu m (450 cm(-1)) with wavenumber resolution of about 0.013 cm(-1) in the IR to 0.769 mu m (13000 cm(-1)). In this paper, the techniques and tests employed for the telescope mirror construction are described. An innovative technique for secondary alignment for Hindle's tests of a Cassegrain utilizing a He-Ne laser is presented. Telescope mountings for positioning and alignment with the FTIR are briefly discussed, as well as radiometric and calibration parameters for the integrated system. C1 USN, Primary Stand Dept, San Diego, CA 92135 USA. RP Wolk, M (reprint author), USN, Primary Stand Dept, Aviat Depot N Island,Code 41440,Bldg 469, San Diego, CA 92135 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 0-8194-2799-3 J9 P SOC PHOTO-OPT INS PY 1998 VL 3352 BP 819 EP 832 DI 10.1117/12.319307 PG 14 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BL66H UT WOS:000076232300081 ER PT S AU Aha, DW Maney, T Breslow, LA AF Aha, DW Maney, T Breslow, LA BE Smyth, B Cunningham, P TI Supporting dialogue inferencing in conversational case-based reasoning SO ADVANCES IN CASE-BASED REASONING SE LECTURE NOTES IN ARTIFICIAL INTELLIGENCE LA English DT Article; Proceedings Paper CT 4th European Workshop on Case-Based Reasoning (EWCBR 98) CY SEP 23-25, 1998 CL TRINITY COLL, DUBLIN, IRELAND HO TRINITY COLL AB Dialogue inferencing is the knowledge-intensive process of inferring aspects of a user's problem from its partial description. Conversational case-based reasoning (CCBR) systems, which interactively and incrementally elicit a user's problem description, suffer from poor retrieval efficiency (i.e., they prompt the user with questions that the user has already implicitly answered) unless they perform dialogue inferencing. The standard method for dialogue inferencing in CCBR systems requires library designers to supply explicit inferencing rules. This approach is problematic (e.g., maintenance is difficult). We introduce an alternative approach in which the CCBR system guides the library designer in building a domain model. This model and the partial problem description are then given to a query retrieval system (PARXA-DB) to infer any implied answers during a conversation. In an initial empirical evaluation in the NaCoDAE CCBR tool, our approach improved retrieval efficiency without sacrificing retrieval precision. C1 USN, Res Lab, Ctr Appl Res Artif Intelligence, Washington, DC 20375 USA. RP Aha, DW (reprint author), USN, Res Lab, Ctr Appl Res Artif Intelligence, Code 5510, Washington, DC 20375 USA. NR 18 TC 12 Z9 12 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 3-540-64990-5 J9 LECT NOTES ARTIF INT PY 1998 VL 1488 BP 262 EP 273 PG 12 WC Computer Science, Artificial Intelligence SC Computer Science GA BN96D UT WOS:000083673900023 ER PT S AU Chafe, JN Green, GF AF Chafe, JN Green, GF BE Kittel, P TI Neodymium-ribbon-regenerator cooling performance in a two-stage Gifford-McMahon refrigerator SO ADVANCES IN CRYOGENIC ENGINEERING, VOL 43 PTS A AND B SE ADVANCES IN CRYOGENIC ENGINEERING LA English DT Proceedings Paper CT Joint Cryogenic Engineering / International Cryogenic Materials Conference CY 1997 CL PORTLAND, OR SP Cabot Performance Mat, Cryogas Int Inc, Int Inst Refrigerat, Oxford Magnet Technol & Oxford Superconductor Technol, NorthW Nat Gas, Wah Chang AB This work is part of an ongoing study into the way material configuration (i.e. flow geometry) can affect the performance of low-temperature regenerators. This work demonstrates a new regenerator configuration and fabrication technique for Gifford-McMahon (GM) refrigerators that operate at temperatures near 4.5 K. This new style regenerator promises to be less expensive, more reliable and perhaps provide better cooling power. A regenerator was assembled from Neodymium ribbon that was approximately 0.32 cm (1/8 in.) wide and 0.025 cm (0.010 in.) thick. Neodymium was chosen because it has a relatively high volumetric heat capacity at temperatures below 10 K and it is a pure metal that can be drawn and formed with relative ease. Small ridges (approximately 0.0025 cm (0.001 in.) high) were embossed on one face of the ribbon. The ribbon was wound into coils similar to the way adhesive tape is wound into rolls. The small ridges on the ribbon provide spacing between the wound layers creating flow passages for gas. Several coils of ribbon were stacked one on top of another inside a stainless steel tube. This assembly formed the second stage regenerator. By selecting ribbon with different thickness and ridge heights the void fraction as well as the amount of heat transfer surface area of the regenerator could be controlled. Test results are presented for two regenerators with ribbon geometry, one with a void fraction of about 20% and another with 15%. Test results include measurements of the pressure drop that occurs when gas flows through each regenerator as well as the cooling performance of a GM. refrigerator while utilizing these regenerators. This data is compared to data for the more conventionally designed regenerator constructed from spherical Nd powder that has a void fraction of about 35%. C1 USN, Ctr Surface Warfare, Carderock Div, Annapolis, MD 21402 USA. RP Chafe, JN (reprint author), USN, Ctr Surface Warfare, Carderock Div, Annapolis, MD 21402 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU PLENUM PRESS DIV PLENUM PUBLISHING CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0065-2482 BN 0-306-45807-1 J9 ADV CRYOG ENG PY 1998 VL 43 BP 1589 EP 1596 PN A AND B PG 4 WC Thermodynamics; Engineering, Electrical & Electronic; Engineering, Mechanical SC Thermodynamics; Engineering GA BL67N UT WOS:000076284800199 ER PT S AU Chafe, JN Green, GF AF Chafe, JN Green, GF BE Kittel, P TI Performance of a low-temperature Gifford-McMahon refrigerator utilizing a neodymium disk regenerator SO ADVANCES IN CRYOGENIC ENGINEERING, VOL 43 PTS A AND B SE ADVANCES IN CRYOGENIC ENGINEERING LA English DT Proceedings Paper CT Joint Cryogenic Engineering / International Cryogenic Materials Conference CY 1997 CL PORTLAND, OR SP Cabot Performance Mat, Cryogas Int Inc, Int Inst Refrigerat, Oxford Magnet Technol & Oxford Superconductor Technol, NorthW Nat Gas, Wah Chang AB In this study, the cooling capability of a Gifford-McMahon (GM) refrigerator has been dramatically increased at temperatures near 4.5 K with no significant increase in input power. This increase in low temperature cooling power can be attributed to a change in design in the low temperature regenerative heat exchanger (regenerator). This regenerator was constructed by precisely forming flow holes through disks of neodymium (Nd) which allowed the reduction of the void fraction from about 35%, for conventionally designed regenerators that utilize spheres, to approximately 10%. Neodymium was chosen because it has a relatively high volumetric heat capacity at temperatures below 10 K and it is a pure metal that can be extruded and drawn with relative ease. The flow holes in the disks were formed using a technique similar to the one used to fabricate multi-filamentary NbTi superconducting wire. Approximately fifty disks, each separated fr om the next by a porous plastic cloth material, were stacked in a stainless steel tube to form the regenerator. The cooling performance of a Leybold Kelcool 4.2(R) refrigerator with this regenerator installed as its second stage heat exchanger is presented here and compared to its performance with the factory standard regenerator which uses Nd spheres. The new design improved cooling capacity by more than two fold at temperatures near 4.5 K. C1 USN, Ctr Surface Warfare, Carderock Div, Annapolis, MD 21402 USA. RP Chafe, JN (reprint author), USN, Ctr Surface Warfare, Carderock Div, Annapolis, MD 21402 USA. NR 0 TC 2 Z9 3 U1 0 U2 0 PU PLENUM PRESS DIV PLENUM PUBLISHING CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0065-2482 BN 0-306-45807-1 J9 ADV CRYOG ENG PY 1998 VL 43 BP 1783 EP 1790 PN A AND B PG 4 WC Thermodynamics; Engineering, Electrical & Electronic; Engineering, Mechanical SC Thermodynamics; Engineering GA BL67N UT WOS:000076284800225 ER PT S AU Ewart, L AF Ewart, L BE Nair, KM Bhalla, AS TI Analysis of flexural strength and failure in PMN-PT SO ADVANCES IN DIELECTRIC CERAMIC MATERIALS SE CERAMIC TRANSACTIONS LA English DT Proceedings Paper CT International Symposium on Dielectric Ceramics - Processing, Properties, and Applications at the 99th Annual Meeting of the American-Ceramic-Society CY MAY 05-07, 1997 CL CINCINNATI, OH SP Amer Ceram Soc AB Lead magnesium niobate in solid solution with lead titanate (PMN-PT) and doped with either barium or lanthanum is an electrostrictive material under development as the active element in some sonar transducer applications. Unexpected element failures have caused concern about the mechanical integrity of doped PMN-PT. This study measured the flexural strength and calculated the Weibull modulus of doped PMN-PT and of poled and unpoled PZT from various vendors. The results show that poled PZT is 2-3 times stronger than doped PMN-PT, depending upon vendor. The low strength of doped PMN-PT is attributed to large critical flaws with average dimensions in the 100 to 200 mu m range. C1 USN, Undersea Warfare Ctr, Newport, RI 02841 USA. RP Ewart, L (reprint author), USN, Undersea Warfare Ctr, Code 2131,Bldg 1170,1176 Howell St, Newport, RI 02841 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, WESTERVILLE, OH 43081-8720 USA SN 1042-1122 BN 1-57498-033-5 J9 CERAM TRANS PY 1998 VL 88 BP 337 EP 344 PG 8 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA BL07Z UT WOS:000074200800030 ER PT S AU Krowne, CM AF Krowne, CM BE Hawkes, PW TI Dyadic Green's function microstrip circulator theory for inhomogeneous ferrite with and without penetrable walls SO ADVANCES IN IMAGING AND ELECTRON PHYSICS, VOL 103 SE Advances in Imaging and Electron Physics LA English DT Review ID CYLINDRICAL DIELECTRIC RESONATOR; DEPOSITION; FREQUENCY; FILMS C1 Naval Res Lab, Microwave Technol Branch, Div Elect Sci & Technol, Washington, DC USA. RP Naval Res Lab, Microwave Technol Branch, Div Elect Sci & Technol, Washington, DC USA. NR 30 TC 3 Z9 3 U1 1 U2 2 PU ELSEVIER ACADEMIC PRESS INC PI SAN DIEGO PA 525 B STREET, SUITE 1900, SAN DIEGO, CA 92101-4495 USA SN 1076-5670 BN 0-12-014745-9 J9 ADV IMAG ELECT PHYS JI Adv. Imag. Electron Phys. PY 1998 VL 103 BP 151 EP 275 DI 10.1016/S1076-5670(08)70016-8 PG 125 WC Physics, Applied SC Physics GA BM62U UT WOS:000079287400003 ER PT S AU Horwitz, JS Chang, W Carter, AC Pond, JM Kirchoefer, SW Chrisey, DB Stroud, RM Levy, J Hubert, C AF Horwitz, JS Chang, W Carter, AC Pond, JM Kirchoefer, SW Chrisey, DB Stroud, RM Levy, J Hubert, C BE Singh, RK Lowndes, DH Chrisey, DB Fogarassy, E Narayan, J TI Pulsed laser deposition of (Ba,Sr)TiO3 ferroelectric thin films 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 Single phase, (100) oriented Ba0.5Sr0.5TiO3 (BST) thin films have been deposited onto (100) LaAlO3, SrTiO3, and MgO substrates using pulsed laser deposition (PLD). Interdigitated capacitors patterned on top of the ferroelectric film have been used to measure the dielectric constant and dissipation factor of these films as a function of DC bias and temperature at 1 MHz and as a function of DC bias and frequency (1 to 20 GHz) at room temperature. At room temperature, the capacitance can be reduced by as much as a factor of 4 using an electric field of less than or equal to 80 kV/cm. The dielectric properties (% tuning and dielectric loss) of the ferroelectric film is sensitive to both the deposition and post processing conditions. Optical imaging of the ferroelectric films using confocal scanning optical microscopy (CSOM) shows reproducible polarization fluctuations over sub-micrometer length scales. Dielectric loss in the ferroelectric film is reduced through a combination of post deposition processing and donor/acceptor doping of the films. A zero field tan delta = 0.01 - 0.005 has been measured for BST films which show significant tuning at microwave frequencies. C1 USN, Res Lab, Washington, DC 20375 USA. RP Horwitz, JS (reprint author), USN, Res Lab, Washington, DC 20375 USA. RI Stroud, Rhonda/C-5503-2008 OI Stroud, Rhonda/0000-0001-5242-8015 NR 0 TC 0 Z9 0 U1 2 U2 3 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 163 EP 173 PG 11 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Optics SC Materials Science; Optics GA BM12Q UT WOS:000077696000024 ER PT S AU Chang, W Horwitz, JS Pond, JM Kirchoefer, SW Chrisey, DB AF Chang, W Horwitz, JS Pond, JM Kirchoefer, SW Chrisey, DB BE Singh, RK Lowndes, DH Chrisey, DB Fogarassy, E Narayan, J TI Pulsed laser deposition of BaxSr1-xTiO3 thin films for frequency agile microwave electronics 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 Oriented, single phase thin films (similar to 5000 Angstrom thick) of BaxSr1-xTiO3 (BST) have been deposited on to (100) MgO and LaAlO3 (LAO) single crystal substrates using pulsed laser deposition (PLD). A strong correlation is observed between the microstructure of the deposited film and the dielectric tuning and loss at microwave frequencies. Microstructural defects observed in as deposited films include strain, due to film substrate lattice mismatch and oxygen and cation vacancies. Compensation of the ablation target with excess Ba and Sr is observed to increase the dielectric constant and to reduce the dielectric loss. Post-deposition, bomb annealing of films at high temperatures (1250 degrees C) is observed to fill oxygen vacancies and increase grain sim. The difference in the dielectric behavior for as-deposited and low temperature annealed BST films on MgO and BST films on LAO is observed and may be attributed to the differences in film stress. A further improvement in the dielectric behavior is observed by the addition of donor/acceptor dopants such as Mn. The data shows that ferroelectric thin films can be used to build tunable microwave circuits that offer significant performance advantages over devices made from conventional semiconducting materials.Oriented, single phase thin films (similar to 5000 Angstrom thick) of BaxSr1-xTiO3 (BST) have been deposited on to (100) MgO and LaAlO3 (LAO) single crystal substrates using pulsed laser deposition (PLD). A strong correlation is observed between the microstructure of the deposited film and the dielectric tuning and loss at microwave frequencies. Microstructural defects observed in as deposited films include strain, due to film substrate lattice mismatch and oxygen and cation vacancies. Compensation of the ablation target with excess Ba and Sr is observed to increase the dielectric constant and to reduce the dielectric loss. Post-deposition, bomb annealing of films at high temperatures (1250 degrees C) is observed to fill oxygen vacancies and increase grain sim. The difference in the dielectric behavior for as-deposited and low temperature annealed BST films on MgO and BST films on LAO is observed and may be attributed to the differences in film stress. A further improvement in the dielectric behavior is observed by the addition of donor/acceptor dopants such as Mn. The data shows that ferroelectric thin films can be used to build tunable microwave circuits that offer significant performance advantages over devices made from conventional semiconducting materials. C1 USN, Res Lab, Washington, DC 20375 USA. RP Chang, W (reprint author), USN, Res Lab, Code 6670,4555 Overlook Ave SW, Washington, DC 20375 USA. NR 0 TC 6 Z9 6 U1 0 U2 1 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 205 EP 210 PG 6 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Optics SC Materials Science; Optics GA BM12Q UT WOS:000077696000030 ER PT B AU Grinstein, FF AF Grinstein, FF BE Frisch, U TI Dynamics of countercurrent square jets SO ADVANCES IN TURBULENCE VII SE FLUID MECHANICS AND ITS APPLICATIONS LA English DT Proceedings Paper CT 7th European Turbulence Conference (ETC7) CY JUN 30-JUL 03, 1998 CL ST JEAN CAP FERRAT, FRANCE SP EUROMECH, ERCOFTAC C1 USN, Res Lab, Computat Phys & Fluid Dynam Lab, Washington, DC 20375 USA. RP Grinstein, FF (reprint author), USN, Res Lab, Computat Phys & Fluid Dynam Lab, Code 6410, Washington, DC 20375 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 0-7923-5115-0 J9 FLUID MEC A PY 1998 VL 46 BP 151 EP 154 PG 4 WC Engineering, Mechanical; Mechanics SC Engineering; Mechanics GA BL94N UT WOS:000077253500037 ER PT B AU Reeter, C Gavaskar, A Gupta, N Sass, B AF Reeter, C Gavaskar, A Gupta, N Sass, B BE Smith, JW TI Permeable reactive wall remediation of chlorinated hydrocarbons in groundwater, NAS Moffett Field, Mountain View, California SO AFTER THE RAIN HAS FALLEN LA English DT Proceedings Paper CT International Water Resources Engineering Conference on Water Resources Development and Protection CY AUG 03-07, 1998 CL MEMPHIS, TN SP Amer Soc Civil Engineers, Water Resources Engn Div, Amer Soc Civil Engineers, W Tennessee Branch, Univ Memphis, Ground Water Inst, US Geol Survey AB The permeable reactive wall or barrier is an innovative technology for the remediation of groundwater contaminated with chlorinated hydrocarbons, such as trichloroethene (TCE), perchloroethene (PCE), dichloroethene (DCE), vinyl chloride (VC), and others. The technology is based on a chemical reaction, in which zero-valent iron particles react with chlorinated hydrocarbons in groundwater to produce non-toxic, readily biodegradable, light hydrocarbon C2-C5 compounds (ethanes, ethenes, etc.), iron and chloride ions, and hydroxides. Remediation of contaminated groundwater by conventional pump-and-treat systems is usually very difficult, long-term, costly, and generally ineffective. The unique benefit of the permeable reactive wail technology is that it can passively remediate the chlorinated hydrocarbons in groundwater using the natural now properties of a site and no external energy is required. Permeable reactive walls have been identified by the U.S. Environmental Protection Agency (EPA, 1995) as an emerging technology for cleanup of groundwater contaminated with chlorinated solvents. C1 USN, Facil Engn Serv Ctr, Port Hueneme, CA 93041 USA. RP Reeter, C (reprint author), USN, Facil Engn Serv Ctr, 1100 23rd Ave, Port Hueneme, CA 93041 USA. NR 0 TC 0 Z9 0 U1 0 U2 2 PU AMER SOC CIVIL ENGINEERS PI NEW YORK PA UNITED ENGINEERING CENTER, 345 E 47TH ST, NEW YORK, NY 10017-2398 USA BN 0-7844-0362-7 PY 1998 BP 153 EP 158 PG 6 WC Engineering, Civil; Environmental Sciences; Water Resources SC Engineering; Environmental Sciences & Ecology; Water Resources GA BL59T UT WOS:000075967000026 ER PT S AU von Berg, DCL Kruer, MR AF von Berg, DCL Kruer, MR BE Fishell, WG Andraitis, AA Fagan, MS Greer, JD Norton, MC TI Image compression for airborne reconnaissance 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 image compression; airborne reconnaissance; JPEG; JPEG 2000 AB The volume of digital imagery generated by existing and planned airborne reconnaissance systems requires the use of lossy compression techniques in order to store the real-time imagery on-board or transmit it to a ground station. The government is migrating compression used for reconnaissance applications from proprietary techniques to national and international standards (JPEG, downsample JPEG, JPEG 2000) in order to provide a more seamless image dissemination path. This paper describes the requirements for image compression in advanced tactical reconnaissance systems and compares the performance of national and international lossy compression techniques. C1 USN, Res Lab, Washington, DC 20375 USA. RP von Berg, DCL (reprint author), USN, Res Lab, Code 5636,4555 Overlook Ave, Washington, DC 20375 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 0-8194-2886-8 J9 P SOC PHOTO-OPT INS PY 1998 VL 3431 BP 2 EP 13 DI 10.1117/12.330202 PG 12 WC Engineering, Aerospace; Imaging Science & Photographic Technology SC Engineering; Imaging Science & Photographic Technology GA BM19T UT WOS:000078007900001 ER PT S AU Grossmann, JM Bowles, J Haas, D Antoniades, JA Grunes, MR Palmadesso, P Gillis, D Tsang, KY Baumback, M Daniel, M Fisher, J Triandaf, I AF Grossmann, JM Bowles, J Haas, D Antoniades, JA Grunes, MR Palmadesso, P Gillis, D Tsang, KY Baumback, M Daniel, M Fisher, J Triandaf, I BE Shen, SS Descour, MR TI Hyperspectral analysis and target detection system for the Adaptive Spectral Reconnaissance Program (ASRP) SO ALGORITHMS FOR MULTISPECTRAL AND HYPERSPECTRAL IMAGERY IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Algorithms for Multispectral and Hyperspectral Imagery IV CY APR 13-14, 1998 CL ORLANDO, FL SP Soc Photo Opt Instrumentat Engineers DE real-time hyperspectral analysis; ROC; ATR AB A multiprocessor version of the ORASIS hyperspectral analysis program has been implemented in support of the ASRP. In brief, the long-term technical objectives of the ASRP are to demonstrate the feasibility and military utility of real-time target detection from uncrewed air vehicles using hyperspectral data. This paper presents a preliminary assessment of ORASIS performance and describes the ORASIS development effort designed to meet the ASRP goals. Real-time performance of the analysis program and its potential effectiveness as a target detection method are demonstrated. C1 USN, Res Lab, Remote Sensing Div, Washington, DC 20375 USA. RP Grossmann, JM (reprint author), USN, Res Lab, Remote Sensing Div, Washington, DC 20375 USA. NR 0 TC 20 Z9 20 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 0-8194-2821-3 J9 P SOC PHOTO-OPT INS PY 1998 VL 3372 BP 2 EP 13 DI 10.1117/12.312591 PG 12 WC Engineering, Aerospace; Remote Sensing; Optics SC Engineering; Remote Sensing; Optics GA BL36N UT WOS:000075290800001 ER PT S AU Tsang, KY Grossmann, JM Palmadesso, PJ Antoniades, JA Baumback, MM Bowles, JH Daniel, M Fisher, J Haas, D AF Tsang, KY Grossmann, JM Palmadesso, PJ Antoniades, JA Baumback, MM Bowles, JH Daniel, M Fisher, J Haas, D BE Shen, SS Descour, MR TI Evaluation of endmember selection techniques and performance results from ORASIS hyperspectral analysis SO ALGORITHMS FOR MULTISPECTRAL AND HYPERSPECTRAL IMAGERY IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Algorithms for Multispectral and Hyperspectral Imagery IV CY APR 13-14, 1998 CL ORLANDO, FL SP Soc Photo Opt Instrumentat Engineers DE ROC; hyperspectral AB In this work, we generate ROC curves on real and synthetic scenes and develop scoring methods to evaluate the performance of the ORASIS hyperspectral algorithm. The goal of this effort is to improve the overall performance of ORASIS, focusing on the endmember selection methods. ROC curve evaluations have been performed on hyperspectral data sets from different scenes. We have scored by target and by target pixel. A scene generator has been developed allowing many features: combination of real or synthetic background and multiple, distinct targets; user-defined angle of target spectrum to background subspace; and user-specified non-uniform target/background transparency. C1 USN, Res Lab, Remote Sensing Div, Washington, DC 20375 USA. RP Tsang, KY (reprint author), USN, Res Lab, Remote Sensing Div, Washington, DC 20375 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 0-8194-2821-3 J9 P SOC PHOTO-OPT INS PY 1998 VL 3372 BP 43 EP 50 DI 10.1117/12.312607 PG 8 WC Engineering, Aerospace; Remote Sensing; Optics SC Engineering; Remote Sensing; Optics GA BL36N UT WOS:000075290800004 ER PT S AU Rogers, GW Mansfield, AW Rais, H Poehler, PL AF Rogers, GW Mansfield, AW Rais, H Poehler, PL BE Zelnio, EG TI IFSAR phase unwrapping in the presence of Dirichlet boundary conditions 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; interferometry; IFSAR; phase unwrapping AB Phase unwrapping is one of the key computational elements in digital elevation model generation from interferometric SAR. In this paper we present a reformulation of the weighted least squares phase unwrapping approach that incorporates Dirichlet boundary conditions. The application of this formulation to the incorporation of control points into the solution as well as for unwrapping the interferogram in stages is discussed. The ability of the weighted least squares approach to fully unwrap an interferogram can be very dependent on the weight matrix used. This has led us to develop an adaptive approach to updating the weight matrix to be used in conjunction with our weighted least squares approach. Examples along with preliminary results based on ERS data will be presented. C1 USN, Ctr Surface Warfare, Dahlgren Div, Dahlgren, VA 22448 USA. RP Rogers, GW (reprint author), USN, Ctr Surface Warfare, Dahlgren Div, Code G50, Dahlgren, VA 22448 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 25 EP 32 DI 10.1117/12.321832 PG 8 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BL85L UT WOS:000076935900003 ER PT B AU Valeri, CR de Wit, HJC Sibinga, CTS de Vries, EGE AuBuchon, JP Winslow, RM Boralessa, H Fratantoni, JC Middleton, S de Leij, L Goodnough, LT Nicolson, DM Lust, A AF Valeri, CR de Wit, HJC Sibinga, CTS de Vries, EGE AuBuchon, JP Winslow, RM Boralessa, H Fratantoni, JC Middleton, S de Leij, L Goodnough, LT Nicolson, DM Lust, A BE Sibinga, CTS Das, PC Fratantoni, JC TI Chemical and biological alternatives - Discussion SO ALTERNATIVE APPROACHES TO HUMAN BLOOD RESOURCES IN CLINICAL PRACTICE SE DEVELOPMENTS IN HEMATOLOGY AND IMMUNOLOGY LA English DT Proceedings Paper CT 22nd International Symposium on Blood Transfusion CY 1997 CL GRONINGEN, NETHERLANDS SP Red Cross Blood Bank Noord Nederland C1 USN, Blood Res Lab, Boston, MA USA. RP Valeri, CR (reprint author), USN, Blood Res Lab, Boston, MA USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 0-7923-8305-2 J9 DEV HEMATOL PY 1998 VL 33 BP 123 EP 131 PG 9 WC Hematology SC Hematology GA BM52C UT WOS:000078948900013 ER PT B AU Valeri, CR Crowley, P Loscalzo, J AF Valeri, CR Crowley, P Loscalzo, J BE Sibinga, CTS Das, PC Fratantoni, JC TI Indications for red blood cell transfusion SO ALTERNATIVE APPROACHES TO HUMAN BLOOD RESOURCES IN CLINICAL PRACTICE SE DEVELOPMENTS IN HEMATOLOGY AND IMMUNOLOGY LA English DT Proceedings Paper CT 22nd International Symposium on Blood Transfusion CY 1997 CL GRONINGEN, NETHERLANDS SP Red Cross Blood Bank Noord Nederland ID RECOMBINANT-HUMAN-ERYTHROPOIETIN; UNITED-STATES; JEHOVAH-WITNESSES; CARDIAC MORBIDITY; OXYGEN-TRANSPORT; SURGERY; MORTALITY; ANEMIA; VOLUME; HEMOGLOBIN C1 USN, Blood Res Lab, Boston, MA USA. RP Valeri, CR (reprint author), USN, Blood Res Lab, Boston, MA USA. NR 40 TC 1 Z9 1 U1 0 U2 1 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 0-7923-8305-2 J9 DEV HEMATOL PY 1998 VL 33 BP 209 EP 214 PG 6 WC Hematology SC Hematology GA BM52C UT WOS:000078948900021 ER PT J AU Mack, GR Wilckens, JH McPherson, SA AF Mack, GR Wilckens, JH McPherson, SA TI Subacute scaphoid fractures - A closer look at closed treatment SO AMERICAN JOURNAL OF SPORTS MEDICINE LA English DT Article ID BONE; MANAGEMENT AB Twenty-three subacute scaphoid fractures were retrospectively reviewed to determine the efficacy of nonoperative treatment, All of the patients sought medical attention between 4 weeks and 6 months after injury, and their fractures were classified according to location and stability, Nineteen fractures were observed to radiographic union or until closed treatment was abandoned; four patients were lost to followup. Nine of 10 stable subacute middle-third scaphoid fractures healed with cast immobilization in an average of 19 weeks (range, 11 to 38), and these were compared with a randomly selected group of acute middle-third fractures that healed in an average of 10 weeks (range, 6 to 13), Five of six unstable subacute middle-third fractures healed in an average of 20 weeks, One of these had a symptomatic humpback deformity treated by cheilectomy. Of three subacute proximal-third fractures, only one healed after 29 weeks of closed treatment, This study demonstrates that stable subacute middle-third scaphoid fractures will heal with cast treatment but may take twice as long to do so as stable acute middle-third fractures. Unstable subacute middle-third scaphoid fractures and subacute proximal-third fractures appear less likely to heal with closed treatment. C1 USN, Dept Clin Invest, Med Ctr, San Diego, CA 92134 USA. USN, Dept Orthopaed Surg, Med Ctr, San Diego, CA 92134 USA. RP Mack, GR (reprint author), USN, Dept Clin Invest, Med Ctr, San Diego, CA 92134 USA. NR 21 TC 12 Z9 13 U1 0 U2 0 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 JAN-FEB PY 1998 VL 26 IS 1 BP 56 EP 58 PG 3 WC Orthopedics; Sport Sciences SC Orthopedics; Sport Sciences GA YT555 UT WOS:000071618800010 PM 9474402 ER PT J AU Girgis, NI Sultan, Y Farid, Z Mansour, MM Erian, MW Hanna, LS Mateczun, AJ AF Girgis, NI Sultan, Y Farid, Z Mansour, MM Erian, MW Hanna, LS Mateczun, AJ TI Tuberculous meningitis, Abbassia Fever Hospital - Naval Medical Research Unit No. 3 - Cairo, Egypt, from 1976 to 1996 SO AMERICAN JOURNAL OF TROPICAL MEDICINE AND HYGIENE LA English DT Article ID DEXAMETHASONE; STEROIDS AB A total of 1,430 patients with the presumptive diagnosis of tuberculous meningitis were admitted to the U.S. Naval Medical Research Unit No. 3/Abassia Fever Hospital in Cairo, Egypt from January 1976 to January 1996. Diagnosis was confirmed by culture of the mycobacteria from the cerebrospinal fluid CSF of 857 patients and these patients are included in the final analysis. There were 497 males and 360 females, The patients ranged in age from five months to 55 years. The number of patients admitted during the months of March, April, and May were more than double those admitted during October, November, and December. The duration of symptoms prior to admission ranged from seven to 90 days (mean = 29.5 days). Upon admission, 4% of the patients were alert, 34% were drowsy, and 62% were in a coma. Of the 857 patients studied, 490 (57%) died, 256 (30%) recovered completely, and 11 (13%) recovered with sequelae. The mortality and neurologic sequelae were directly related to the stage of disease and duration of symptoms prior to admission. Mortality was significantly lower in patients admitted in stage 11 and or with short duration of disease compared with those in stage III and or with prolonged duration of symptoms prior to admission. The use of dexamethasone in patients with tuberculous meningitis significantly reduced the ocular complications that occur in these patients and also significantly reduced the fatality rate. C1 USN, Med Res Unit 3, Cairo, Egypt. Abbassia Fever Hosp, Cairo, Egypt. Tanta Univ, Fac Med, Dept Ophthalmol, Tanta, Egypt. RP Girgis, NI (reprint author), USN, Med Res Unit 3, Res Publicat Branch, Attn Code 101 F,PSC 452,Box 5000, FPO, AE 09835 USA. NR 31 TC 89 Z9 94 U1 0 U2 1 PU AMER SOC TROP MED & HYGIENE PI MCLEAN PA 8000 WESTPARK DRIVE SUITE 130, MCLEAN, VA 22101 USA SN 0002-9637 J9 AM J TROP MED HYG JI Am. J. Trop. Med. Hyg. PD JAN PY 1998 VL 58 IS 1 BP 28 EP 34 PG 7 WC Public, Environmental & Occupational Health; Tropical Medicine SC Public, Environmental & Occupational Health; Tropical Medicine GA YT775 UT WOS:000071643800007 PM 9452288 ER PT J AU Watts, DM Callahan, J Rossi, C Oberste, MS Roehrig, JT Wooster, MT Smith, JF Cropp, CB Gentrau, EM Karabatsos, N Gubler, D Hayes, CG AF Watts, DM Callahan, J Rossi, C Oberste, MS Roehrig, JT Wooster, MT Smith, JF Cropp, CB Gentrau, EM Karabatsos, N Gubler, D Hayes, CG TI Venezuelan equine encephalitis febrile cases among humans in the Peruvian Amazon River region SO AMERICAN JOURNAL OF TROPICAL MEDICINE AND HYGIENE LA English DT Article ID MONOCLONAL-ANTIBODIES; HEMORRHAGIC-FEVER; SOUTH-AMERICA; VIRUS; IDENTIFICATION; EPITOPES; TC-83 AB A survey was conducted from October 1, 1993 to June 30, 1995 to determine the arboviral etiologies of febrile illnesses in the city of Iquitos in the Amazon River Basin of Peru. The study subjects were patients who were enrolled at medical care clinics or in their homes by Peruvian Ministry of Health (MOH) workers as part of the passive and active disease surveillance program of the MOH. The clinical criterion for enrollment was the diagnosis of a suspected viral-associated, acute, undifferentiated febrile illness of less than or equal to 5 days duration. A total of 598 patients were enrolled in the study. Demographic information, medical history, clinical data, and blood samples were obtained from each patient. The more common clinical features were fever, headache, myalgia, arthralgia, retro-ocular pain, and chills. Sera were tested for virus by the newborn mouse and cell culture assays. Viral isolates were identified initially by immunofluorescence using polyclonal antibody. An ELISA using viral-specific monoclonal antibodies and nucleotide sequence analysis were used to determine the specific variety of the viruses. In addition, thin and thick blood smears were observed for malaria parasites. Venezuelan equine encephalitis (VEE) virus subtype I, variety ID virus was isolated from 10 cases, including three cases in October, November, and December 1993, five cases in January and February 1994, and two cases in June 1995. The ELISA for IgM and IgG antibody indicated that VEE virus was the cause of an additional four confirmed and four presumptive cases, including five from January through March 1994 and three in August 1994. Sixteen cases were positive for malaria. The 18 cases of VEE occurred among military recruits (n = 7), agriculture workers (n = 3), students (n = 3), and general laborers (n = 5). These data indicated that an enzootic strain of VEE virus was the cause of at least 3% (18 of 598) of the cases of febrile illnesses studied in the city of Iquitos in the Amazon Basin region of Peru. C1 USN, Med Res Inst Detachment, NAMRID, Unit 3800, APO, AA 34031 USA. USA, Med Res Inst Infect Dis, Ft Detrick, Frederick, MD 21702 USA. Ctr Dis Control & Prevent, Arbovirus Res Branch, Div Vector Borne Infect Dis, Ft Collins, CO 80522 USA. Peruvian Minist Hlth, Iquitos, Peru. USN, Dept Infect Dis, Med Res Inst, Bethesda, MD 20889 USA. RP Watts, DM (reprint author), USN, Med Res Inst Detachment, NAMRID, Unit 3800, APO, AA 34031 USA. OI Roehrig, John/0000-0001-7581-0479 NR 33 TC 46 Z9 50 U1 0 U2 2 PU AMER SOC TROP MED & HYGIENE PI MCLEAN PA 8000 WESTPARK DRIVE SUITE 130, MCLEAN, VA 22101 USA SN 0002-9637 J9 AM J TROP MED HYG JI Am. J. Trop. Med. Hyg. PD JAN PY 1998 VL 58 IS 1 BP 35 EP 40 PG 6 WC Public, Environmental & Occupational Health; Tropical Medicine SC Public, Environmental & Occupational Health; Tropical Medicine GA YT775 UT WOS:000071643800008 PM 9452289 ER PT J AU Raviprakash, K Sinha, M Hayes, CG Porter, KR AF Raviprakash, K Sinha, M Hayes, CG Porter, KR TI Conversion of dengue virus replicative form RNA (RF) to replicative intermediate (RI) by nonstructural proteins NS-5 and NS-3 SO AMERICAN JOURNAL OF TROPICAL MEDICINE AND HYGIENE LA English DT Article ID NUCLEOTIDE-SEQUENCE; GENOMIC RNA; POLYMERASE; EXPRESSION; INVITRO; STRAIN; ORGANIZATION; PURIFICATION; INITIATION; POLIOVIRUS AB Dengue viruses infect more than 100 million people each year and cause serious clinical manifestations. It is important to understand the replication of these viruses so that therapeutic and/or prophylactic agents may be designed. Dengue virus type 2 nonstructural proteins NS-5 and NS-3 were produced by in vitro transcription and translation of cloned genes. Both proteins possessed RNA-dependent RNA polymerase activity as measured by their ability to convert purified replicative form (RF) RNA to replicative intermediate (RI). The recombinant proteins, however, required one or more cellular protein(s) for their activity, Examination of NS-3 protein sequence revealed heretofore unnoticed sequence similarities with other polymerases. C1 USN, Dept Infect Dis, Med Res Inst, Bethesda, MD 20889 USA. Uniformed Serv Univ Hlth Sci, Dept Med, Bethesda, MD 20814 USA. Henry M Jackson Fdn Advancement Mil Med, Rockville, MD 20852 USA. RP Raviprakash, K (reprint author), USN, Dept Infect Dis, Med Res Inst, Bldg 17,Room 316,8901 Wisconsin Ave, Bethesda, MD 20889 USA. NR 25 TC 14 Z9 16 U1 0 U2 0 PU AMER SOC TROP MED & HYGIENE PI MCLEAN PA 8000 WESTPARK DRIVE SUITE 130, MCLEAN, VA 22101 USA SN 0002-9637 J9 AM J TROP MED HYG JI Am. J. Trop. Med. Hyg. PD JAN PY 1998 VL 58 IS 1 BP 90 EP 95 PG 6 WC Public, Environmental & Occupational Health; Tropical Medicine SC Public, Environmental & Occupational Health; Tropical Medicine GA YT775 UT WOS:000071643800017 PM 9452298 ER PT J AU Hoffman, ME AF Hoffman, ME TI The bull and the silo: An application of curvature SO AMERICAN MATHEMATICAL MONTHLY LA English DT Article C1 USN Acad, Annapolis, MD 21402 USA. RP Hoffman, ME (reprint author), USN Acad, Annapolis, MD 21402 USA. RI Hoffman, Michael/D-9913-2011 OI Hoffman, Michael/0000-0002-9436-7596 NR 0 TC 0 Z9 0 U1 0 U2 0 PU MATHEMATICAL ASSOC AMER PI WASHINGTON PA 1529 18TH STREET NW, WASHINGTON, DC 20036 USA SN 0002-9890 J9 AM MATH MON JI Am. Math. Mon. PD JAN PY 1998 VL 105 IS 1 BP 55 EP 58 DI 10.2307/2589527 PG 4 WC Mathematics SC Mathematics GA YY506 UT WOS:000072154300007 ER PT J CA Wilmer Alabama Math Club TI Evaluation of an integral SO AMERICAN MATHEMATICAL MONTHLY LA English DT Letter C1 USN Acad, Annapolis, MD 21402 USA. RP USN Acad, Annapolis, MD 21402 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MATHEMATICAL ASSOC AMER PI WASHINGTON PA 1529 18TH STREET NW, WASHINGTON, DC 20036 USA SN 0002-9890 J9 AM MATH MON JI Am. Math. Mon. PD JAN PY 1998 VL 105 IS 1 BP 76 EP 77 PG 2 WC Mathematics SC Mathematics GA YY506 UT WOS:000072154300019 ER PT J AU Narang, U Gauger, PR Kusterbeck, AW Ligler, FS AF Narang, U Gauger, PR Kusterbeck, AW Ligler, FS TI Multianalyte detection using a capillary-based flow immunosensor SO ANALYTICAL BIOCHEMISTRY LA English DT Article ID IMMUNOASSAY; SERUM; ASSAY; RADIOIMMUNOASSAY; FOLLITROPIN; LUTROPIN AB A highly sensitive, dual-analyte detection system using capillary-based immunosensors has been designed for explosive detection. This model system consists of two capillaries, one coated with antibodies specific for 2,4,6-trinitrotoluene (TNT) and the other specific for hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) combined into a single device. The fused silica capillaries are prepared by coating anti-TNT and anti-RDX antibodies onto the silanized inner walls using a heterobifunctional crosslinker. After immobilization, the antibodies are saturated with a suitable fluorophore-labeled antigen. A "T" connector is used to continuously flow the buffer solution through the individual capillaries. To perform the assay, an aliquot of TNT or RDX or a mixture of the two analytes is injected into the continuous flow stream. In each capillary, the target analyte displaces the fluorophore-labeled antigen from the binding pocket of the antibody. The labeled antigen displaced from either capillary is detected downstream using two portable spectrofluorometers. The limits of detection for TNT and RDX in the multianalyte format are 44 fmol (100 mu l of 0.1 ng/ml TNT solution) and 224 fmol (100 mu l of 0.5 ng/ml RDX solution), respectively. The entire assay for both analytes can be performed in less than 3 min. (C) 1998 Academic Press. C1 USN, Res Lab, Ctr Biomol Sci & Engn, Washington, DC 20375 USA. Georgetown Univ, Dept Biochem, Washington, DC 20007 USA. Geocenters Inc, Ft Washington, MD 20744 USA. RP Ligler, FS (reprint author), USN, Res Lab, Ctr Biomol Sci & Engn, Code 6900, Washington, DC 20375 USA. NR 28 TC 69 Z9 69 U1 1 U2 7 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0003-2697 J9 ANAL BIOCHEM JI Anal. Biochem. PD JAN 1 PY 1998 VL 255 IS 1 BP 13 EP 19 DI 10.1006/abio.1997.2411 PG 7 WC Biochemical Research Methods; Biochemistry & Molecular Biology; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA YT030 UT WOS:000071557000003 PM 9448837 ER PT J AU Rabbany, SY Piervincenzi, RT Kusterbeck, AW Bredehorst, R Ligler, FS AF Rabbany, SY Piervincenzi, RT Kusterbeck, AW Bredehorst, R Ligler, FS TI Dissociation rate kinetics in a solid-phase flow immunoassay SO ANALYTICAL LETTERS LA English DT Article DE antibody-antigen interactions; solid-phase displacement assay; dissociation kinetics; unoccupied binding sites; flow immunoassay ID IMMOBILIZED ANTIBODIES; BINDING CONSTANTS; AFFINITY AB Solid-phase displacement assays allow extremely fast analyses when performed under continuous flow conditions. Continuous dissociation of labeled antigen from the immobilized saturated antibodies occurs even in the absence of competing unlabeled antigen. This spontaneous dissociation creates more unoccupied antibody binding sites which affect the magnitude of the signal generated. In order to evaluate the impact of this phenomenon in more detail, we extended the law of mass action to solid-phase binding assays and analyzed the dissociation kinetics of labeled antigen under continuous flow conditions. The effect of the now on the dissociation kinetics was determined by calculation of the apparent dissociation rate constants (k(d)) which increase with an increase in the now rate. These dissociation rate constants are approximately 20- to 30-fold lower than those obtained from displacement studies (i.e., in the presence of competing unlabeled antigen). The difference in the dissociation rate constants obtained in the two studies is most likely a function of the degree of reassociation. The results of this study provide a basis for better understanding antibody kinetics at solid-liquid interfaces under flow conditions. C1 Hofstra Univ, Bioengn Program, Hempstead, NY 11550 USA. USN, Res Lab, Ctr Biomol Sci & Engn, Washington, DC 20375 USA. Univ Hamburg, Dept Biochem & Mol Biol, D-20146 Hamburg, Germany. RP Rabbany, SY (reprint author), Hofstra Univ, Bioengn Program, 104 Weed Hall, Hempstead, NY 11550 USA. NR 15 TC 17 Z9 17 U1 0 U2 0 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 USA SN 0003-2719 J9 ANAL LETT JI Anal. Lett. PY 1998 VL 31 IS 10 BP 1663 EP 1675 PG 13 WC Chemistry, Analytical SC Chemistry GA 106GB UT WOS:000075120600003 ER PT S AU Keys, HJR Jacobs, SS Brigham, LW AF Keys, HJR Jacobs, SS Brigham, LW BE Budd, WF TI Continued northward expansion of the Ross Ice Shelf, Antarctica SO ANNALS OF GLACIOLOGY, VOL 27, 1998 SE ANNALS OF GLACIOLOGY LA English DT Article; Proceedings Paper CT International Symposium on Antarctica and Global Change - Interactions and Impacts CY JUL 13-18, 1997 CL HOBART, AUSTRALIA SP Cooperative Res Ctr Antarctica, SO Ocean (Antarctic CRC), Australian Antarctic Div, Int Glaciol Soc, Global Change & Antarctic program of SCAR ID MASS-BALANCE; RETREAT; FIELD AB The last major calving event along the Ross Ice Shelf (RIS, Antarctica) front occurred a decade ago, following a substantial increase in the rate of ice-front advance in the few years preceding the event. This "B-9" event, on the eastern part of the front between Edward VII Peninsula and Roosevelt Island, removed approximate to 5100 km(2) of ice, about 100 years of advance in that sector, but reduced the ice-shelf area by only 1 %. Since 1987 the entire ice front has continued to advance, more than regaining the area lost during the B-9 event. The western front is now well north of any position recorded during the last 150 years, and it has not experienced major calving for at least 90 years. Ice-front heights generally decrease from east to west, but local variability is high. Elevations are relatively low from 171 degrees to 177 degrees W; the location of "warm" Modified Circumpolar Deep Water circulation beneath the outer ice shelf. Modern heights considerably exceed historical heights between 179 degrees Wand 178 degrees E and are lower west of 174 degrees E, probably due to recent dynamic changes such as rifting and the western advance. The general advance of the RIS front and the period of several decades to more than a century that elapses between major calving events is consistent with a relatively stable ice front. This contrasts with several smaller ice shelves along the Antarctic Peninsula and McMurdo Ice Shelf in the Ross Sea which have retreated substantially during the past few decades. C1 Dept Conservat, Turangi, New Zealand. Columbia Univ, Lamont Doherty Earth Observ, Palisades, NY 10964 USA. USN, Postgrad Sch, Dept Oceanog, Monterey, CA 93943 USA. RP Keys, HJR (reprint author), Dept Conservat, Turangi, New Zealand. NR 26 TC 10 Z9 10 U1 0 U2 1 PU INT GLACIOLOGICAL SOC PI CAMBRIDGE PA LENSFIELD RD, CAMBRIDGE, ENGLAND CB2 1ER SN 0260-3055 BN 0-946417-22-9 J9 ANN GLACIOL PY 1998 VL 27 BP 93 EP 98 PG 6 WC Geochemistry & Geophysics; Geology; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Geochemistry & Geophysics; Geology; Meteorology & Atmospheric Sciences GA BM76J UT WOS:000079713100014 ER PT J AU Leaf, EV AF Leaf, EV TI Comment: venlafaxine overdose and seizure SO ANNALS OF PHARMACOTHERAPY LA English DT Letter C1 USN, Hosp Bremerton, Inpatient Pharm Serv, Bremerton, WA 98312 USA. RP Leaf, EV (reprint author), USN, Hosp Bremerton, Inpatient Pharm Serv, Boone Rd, Bremerton, WA 98312 USA. NR 5 TC 7 Z9 8 U1 0 U2 0 PU HARVEY WHITNEY BOOKS CO PI CINCINNATI PA PO BOX 42696, CINCINNATI, OH 45242 USA SN 1060-0280 J9 ANN PHARMACOTHER JI Ann. Pharmacother. PD JAN PY 1998 VL 32 IS 1 BP 135 EP 136 DI 10.1345/aph.16134c PG 2 WC Pharmacology & Pharmacy SC Pharmacology & Pharmacy GA YT561 UT WOS:000071619400029 PM 9475842 ER PT J AU Lukish, JR Muro, K DeNobile, J Katz, R Williams, J Cruess, DF Drucker, W Kirsch, I Hamilton, SR AF Lukish, JR Muro, K DeNobile, J Katz, R Williams, J Cruess, DF Drucker, W Kirsch, I Hamilton, SR TI Prognostic significance of DNA replication errors in young patients with colorectal cancer SO ANNALS OF SURGERY LA English DT Article ID MICROSATELLITE INSTABILITY; MISMATCH REPAIR; MUTATOR PHENOTYPE; COLON-CANCER; CARCINOMA; CELLS; SEQUENCES; TOLERANT; HISTORY AB Objective To determine:he DNA replication error (RER) status in young patients with colorectal cancer (CRC), and to compare the clinical and pathologic characteristics of RER-positive and RER-negative cases. Summary Background Data. Recent studies suggest that patients with RER-positive CRC have an improved prognosis. Further data are required to confirm this observation in young CRC patients. Methods All patients 40 years of age and younger with CRC admitted to the National Naval Medical Center between 1970 and 1992 were considered for inclusion in the study. After review, 36 patients for when? the original archived pathology specimen could be retrieved sewed as the study population. The RER status was determined using a previously described polymerase chain reaction-based assay. The clinical and pathologic features and survival data were compared is RER status. Results RER-positive tumors were found in 17 cases (47%). There was no significant difference in Dukes' stage or histologic grade at the time of diagnosis between patients with PER-positive tumors compared to RER-negative tumors. Patients with PER-positive tumors were found to have an improved prognosis: the 5-year survival probability for patients with RER-positive tumors was 68%, as compared to 32% for patients with RER-negative tumors (p < 0.05). Conclusions RER-positive tumors are common in young patients with CRC, and patients with RER-positive tumors have a significantly improved prognosis. Because of their young age, survival data and prognosis play an important role in the overall treatment plan of young patients with CRC. Therefore, knowledge of RER status could affect initial therapy, postoperative chemotherapy, and follow-up. C1 Natl Naval Med Ctr, Dept Surg, Bethesda, MD 20814 USA. Natl Naval Med Ctr, Dept Pathol, Bethesda, MD USA. Johns Hopkins Univ, Sch Med, Dept Pathol, Baltimore, MD 21218 USA. Johns Hopkins Univ, Sch Med, Ctr Oncol, Baltimore, MD 21218 USA. Uniformed Serv Univ Hlth Sci, Dept Surg, Bethesda, MD 20814 USA. Uniformed Serv Univ Hlth Sci, Dept Biostat, Bethesda, MD 20814 USA. NCI, USN, Med Oncol Branch, Bethesda, MD 20892 USA. RP Lukish, JR (reprint author), Natl Naval Med Ctr, Dept Surg, 8901 Wisconsin Ave, Bethesda, MD 20814 USA. FU NCI NIH HHS [CA47527, CA62924] NR 25 TC 95 Z9 98 U1 0 U2 0 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 JAN PY 1998 VL 227 IS 1 BP 51 EP 56 DI 10.1097/00000658-199801000-00008 PG 6 WC Surgery SC Surgery GA YR054 UT WOS:000071453200008 PM 9445110 ER PT J AU Hanafi, HA El Sawaf, BM Fryauff, DJ Beavers, GM Tetreault, GE AF Hanafi, HA El Sawaf, BM Fryauff, DJ Beavers, GM Tetreault, GE TI Susceptibility to Leishmania major of different populations of Phlebotomus papatasi (Diptera : Psychodidae) from endemic and non-endemic regions of Egypt SO ANNALS OF TROPICAL MEDICINE AND PARASITOLOGY LA English DT Article ID SURFACE LIPOPHOSPHOGLYCAN; CUTANEOUS LEISHMANIASIS; EXPERIMENTAL-INFECTION; NORTH SINAI; SAND FLIES; TRANSMISSION; VECTORS AB The ability of three populations of Phlebotomus papatasi collected from different areas of Egypt (Sinai, Aswan and Delta regions) to acquire successfully and transmit Leishmania major (Sinai sandfly isolate IPAP/EG/89/SI-177) was evaluated in the laboratory. Flies from each population were fed artificially on infected blood suspensions, using a chick-skin-membrane feeding apparatus, and naturally on infected mice. Samples of fed flies were dissected and examined microscopically to determine the infection rate and intensity of parasite infection. The Aswan population had a significantly lower feeding rate (16.2%) than the Sinai (51.2%) and Delta (69.7%) populations (P < 0.0001). The infection rate for the Sinai population was significantly higher (65.9%) than the rate for the Delta (52.3%; P < 0.05) and slightly higher than that for the Aswan (62.5%). No differences were observed in the intensity of L. major infection in the midguts of the sandflies examined from any of the three populations. When flies from each population were fed naturally on BALB/c mice infected with L. major, the feeding rates of the three populations showed a similar pattern to that seen in the membrane feeds, with the Aswan population having the lowest rate. In each of two separate trials for each population, a group of artificially infected flies was refed on uninfected BALB/c mice. Thirty-six days following exposure to the infected sandflies in the Sinai population, a leishmanial lesion was observed on the corner of one animal's mouth. These observations provide the final piece of evidence that P. papatasi is a vector of L. major in Egypt. C1 USN, Med Res Unit 3, Cairo, Egypt. Ain Shams Univ, Fac Sci, Dept Entomol, Cairo, Egypt. RP Hanafi, HA (reprint author), USN, Med Res Unit 3, Res Publicat Branch, Code 101F,PSC 452,POB 5000, FPO, AE 09835 USA. NR 29 TC 7 Z9 12 U1 0 U2 2 PU CARFAX PUBL CO PI ABINGDON PA PO BOX 25, ABINGDON, OXFORDSHIRE, ENGLAND OX14 3UE SN 0003-4983 J9 ANN TROP MED PARASIT JI Ann. Trop. Med. Parasitol. PD JAN PY 1998 VL 92 IS 1 BP 57 EP 64 PG 8 WC Public, Environmental & Occupational Health; Parasitology; Tropical Medicine SC Public, Environmental & Occupational Health; Parasitology; Tropical Medicine GA YT688 UT WOS:000071632500006 PM 9614454 ER PT J AU Oran, ES Oh, CK Cybyk, BZ AF Oran, ES Oh, CK Cybyk, BZ TI Direct simulation Monte Carlo: Recent advances and applications SO ANNUAL REVIEW OF FLUID MECHANICS LA English DT Review DE rarefied gases; microchannel flows; vapor deposition processes; plasma etch; particle simulations ID BOLTZMANN-EQUATION; GAS-FLOW; PARTICLE SIMULATION; MAGELLAN SPACECRAFT; RAREFIED FLOWS; MODEL; DYNAMICS; SCHEME; AERODYNAMICS; VALIDATION AB The principles of and procedures for implementing direct simulation Monte Carlo (DSMC) are described. Guidelines to inherent and external errors common in DSMC applications are provided. Three applications of DSMC to transitional and nonequilibrium flows are considered: rarefied atmospheric flows, growth of thin films, and microsystems. Selected new, potentially important advances in DSMC capabilities are described: Lagrangian DSMC, optimization on parallel computers, and hybrid algorithms for computations in mixed flow regimes. Finally, the limitations of current computer technology for using DSMC to compute low-speed, high-Knudsen-number flows are outlined as future challenges. C1 USN, Res Lab, Computat Phys & Fluid Dynam Lab, Washington, DC 20375 USA. RP Oran, ES (reprint author), USN, Res Lab, Computat Phys & Fluid Dynam Lab, Code 6404, Washington, DC 20375 USA. EM oran@lcp.nrl.navy.mil; oh@lcp.nrl.navy.mil; cybyk@lcp.nrl.navy.mil NR 113 TC 225 Z9 238 U1 2 U2 61 PU ANNUAL REVIEWS INC PI PALO ALTO PA 4139 EL CAMINO WAY, PO BOX 10139, PALO ALTO, CA 94303-0139 USA SN 0066-4189 J9 ANNU REV FLUID MECH JI Annu. Rev. Fluid Mech. PY 1998 VL 30 BP 403 EP 441 DI 10.1146/annurev.fluid.30.1.403 PG 39 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA YV950 UT WOS:000071880700015 ER PT S AU Latourell, J Wallet, B Copeland, B AF Latourell, J Wallet, B Copeland, B BE Rogers, SK Fogel, DB Bezdek, JC Bosacchi, B TI Genetic algorithm to solve constrained routing problem with applications for cruise missile routing 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 algorithm; parameters; mutation rate; population; obstacle avoidance; path planning AB In this paper the use of a Genetic Algorithm to solve a constrained vehicle routing problem is explored. The problem is two-dimensional with obstacles represented as ellipses of uncertainty surrounding each obstacle point. A route is defined as a series of points through which the vehicle sequentially travels from the starting point to the ending point. The physical constraints of total route length and maximum turn angle are included and appear in the fitness function. In order to be valid, a route must go from start to finish without violating any constraint. The effects that different mutation rates and population sizes have on the algorithm's computation speed and ability to find a high quality route are also explored. Finally, possible applications of this algorithm to the problem of route planning for cruise missiles are discussed. C1 USN, Ctr Surface Warfare, Dahlgren, VA 22448 USA. RP Latourell, J (reprint author), USN, Ctr Surface Warfare, Dahlgren, VA 22448 USA. 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 0-8194-2839-6 J9 P SOC PHOTO-OPT INS PY 1998 VL 3390 BP 490 EP 500 DI 10.1117/12.304839 PG 11 WC Computer Science, Artificial Intelligence; Computer Science, Interdisciplinary Applications; Optics SC Computer Science; Optics GA BK80N UT WOS:000073452600051 ER PT S AU Paiva, CA AF Paiva, CA BE Rogers, SK Fogel, DB Bezdek, JC Bosacchi, B TI Navy theater ballistic missile defense boost multispectral discrimination requirements for low resolution detection, classification and high resolution aimpoint selection 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 AB The U.S. Navy has been requested to provide insightful responses to questions regarding low and high resolution target discrimination and target classification capabilities for short and medium range ballistic missiles (SRBM/MRBM). Specific targets studied for this paper include the solid booster and the associated attitude control system (ACS) liquid divert thruster systems. Discriminants selected include booster and ACS separation debris, as well as fuel vent phenomena. Debris and vent cloud containment and elimination through gaussian suppression techniques have been implemented for low resolution assessment for target detection and tracking. Target gradient edge intensities were extracted for aimpoint selection and will be added to the pattern referencing library database at NSWC, The results of this study indicate an increasing requirement for advanced image processing on the focal plane array of a generic LEAP (light exo-atmospheric projectile) type kill kinetic vehicle (KKV) in order to implement effective target and aimpoint detection/tracking correlation matching routines. C1 USN, Ctr Surface Warfare,Technol Applicat Branch, Joint Warfare Applicat Dept, Syst & Countermeasures Dev Div, Dahlgren, VA 22448 USA. RP Paiva, CA (reprint author), USN, Ctr Surface Warfare,Technol Applicat Branch, Joint Warfare Applicat Dept, Syst & Countermeasures Dev Div, Dahlgren, VA 22448 USA. NR 0 TC 0 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 0-8194-2839-6 J9 P SOC PHOTO-OPT INS PY 1998 VL 3390 BP 532 EP 550 DI 10.1117/12.304845 PG 19 WC Computer Science, Artificial Intelligence; Computer Science, Interdisciplinary Applications; Optics SC Computer Science; Optics GA BK80N UT WOS:000073452600056 ER PT S AU Roman, JE Matthews, PJ Frankel, MY Esman, RD AF Roman, JE Matthews, PJ Frankel, MY Esman, RD BE Lampropoulos, GA Lessard, RA TI Characteristics and impact of fiber gratings in dispersion-based RF beamforming SO APPLICATIONS OF PHOTONIC TECHNOLOGY 3 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT International Conference on Applications of Photonic Technology (ICAPT 98) CY JUL 27-30, 1998 CL OTTAWA, CANADA SP SPIE Int Soc Opt Engn DE fiber-optic beamforming; fiber gratings; dispersion; and fiber grating characterization ID PHASED-ARRAY ANTENNAS; TIME-STEERED ARRAY; PRISM AB The use of fiber gratings in dispersion-based RF beamforming systems is reviewed, The relationship between the beamformer and grating parameters is discussed. Measurements on the RF characteristics of fiber gratings are presented, and their impact on beamformer performance is discussed. C1 USN, Res Lab, Div Opt Sci, Washington, DC 20375 USA. RP Roman, JE (reprint author), USN, Res Lab, Div Opt Sci, Code 5672, Washington, DC 20375 USA. NR 17 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 0-8194-2950-3 J9 P SOC PHOTO-OPT INS PY 1998 VL 3491 BP 316 EP 321 DI 10.1117/12.328747 PG 6 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Optics SC Engineering; Materials Science; Optics GA BM33Q UT WOS:000078414100057 ER PT S AU Gilbreath, GC Rabinovich, WS Mahon, R Corson, MR Kline, JF Resnick, J Merk, HC Vilcheck, MJ AF Gilbreath, GC Rabinovich, WS Mahon, R Corson, MR Kline, JF Resnick, J Merk, HC Vilcheck, MJ BE Lampropoulos, GA Lessard, RA TI Modulating retroreflector architecture using multiple quantum wells for free space optical communications SO APPLICATIONS OF PHOTONIC TECHNOLOGY 3 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT International Conference on Applications of Photonic Technology (ICAPT 98) CY JUL 27-30, 1998 CL OTTAWA, CANADA SP SPIE Int Soc Opt Engn AB In this paper, we describe a demonstration using a Multiple Quantum Well modulator combined with an optical retroreflector which supported a high speed free space optical data link. Video images were transmitted over an 859 nanometer link at a rate of 460 kilo bits per second, where rate of modulation was limited by demonstration hardware, not the modulator. Reflection architectures for the modulator were used although transmission architectures have also been investigated but are not discussed in this paper. The modulator was a GaAs/Al0.3Ga0.7As quantum well which was designed and fabricated for use as a shutter at the Naval Research Laboratory. We believe these are the first results reported demonstrating a high speed free space optical data link using multiple quantum well shutters combined with retroreflectors for viable free space optical communications. C1 USN, Res Lab, Washington, DC 20375 USA. RP Gilbreath, GC (reprint author), USN, Res Lab, Washington, DC 20375 USA. NR 4 TC 15 Z9 15 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 0-8194-2950-3 J9 P SOC PHOTO-OPT INS PY 1998 VL 3491 BP 581 EP 586 DI 10.1117/12.328588 PG 6 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Optics SC Engineering; Materials Science; Optics GA BM33Q UT WOS:000078414100103 ER PT S AU Dominguez, DD Hagans, PL Skelton, EF Qadri, SB Nagel, DJ AF Dominguez, DD Hagans, PL Skelton, EF Qadri, SB Nagel, DJ BE Mini, SM Stock, SR Perry, DL Terminello, LJ TI In situ monitoring of the electrochemical absorption of deuterium into palladium by x-ray diffraction using synchrotron-wiggler radiation SO APPLICATIONS OF SYNCHROTRON RADIATION TECHNIQUES TO MATERIALS SCIENCE IV SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Applications of Synchrotron Radiation Techniques to Materials Science IV CY APR 13-17, 1998 CL SAN FRANCISCO, CA SP Phys Electr, Blake Ind, Luxel Corp, Lawrence Livermore Natl Lab, Dept Chem & Mat Sci, Lawrence Berkeley Natl Lab, Adv Light Source, Brookhaven Natl Lab, Natl Synchrotron Light Source AB With low energy x-rays, such as those from a Cu x-ray tube, only the outer few microns of a metallic sample can be probed. This low penetrating power prohibits structural studies from being carried out on the interior of an electrode in an electrochemical cell because of absorption by the cell material, electrodes and the electrolyte. The work described in this paper circumvents this problem by utilizing high energy, high brightness x-rays produced on the superconducting wiggler beam line, X-17C, at the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory. The penetrating power of the higher energy x-rays allowed Pd diffraction spectra to be obtained in-situ on a 1 mm diameter Pd wire cathode during electrolysis of heavy water. Moreover, the beam (28 x 28 mu m in cross-section) allowed diffraction spectra to be acquired as a function of distance across the sample. Spectra were recorded in 50 mu m steps from the edge of the Pd wire to its core. This was done at 2 minute intervals as a function of electrolysis time. The a-p phase transition induced in the Pd while deuterium was electrochemically absorbed was observed by monitoring the Pd-(422) diffraction peaks. Results allowed the diffusion rate and the diffusivity of deuterium atoms in the Pd wire to be determined. Other features of the structural changes associated with the absorption of deuterium into Pd are reported. C1 USN, Res Lab, Washington, DC 20375 USA. RP Dominguez, DD (reprint author), USN, Res Lab, Washington, DC 20375 USA. NR 0 TC 0 Z9 0 U1 1 U2 2 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-430-0 J9 MATER RES SOC SYMP P PY 1998 VL 524 BP 127 EP 132 PG 6 WC Materials Science, Multidisciplinary; Materials Science, Characterization & Testing SC Materials Science GA BL56G UT WOS:000075892800021 ER PT J AU Mohran, ZS Arthur, RR Oyofo, BA Peruski, LF Wasfy, MO Ismail, TF Murphy, JR AF Mohran, ZS Arthur, RR Oyofo, BA Peruski, LF Wasfy, MO Ismail, TF Murphy, JR TI Differentiation of Campylobacter isolates on the basis of sensitivity to boiling in water as measured by PCR-detectable DNA SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Article ID POLYMERASE CHAIN-REACTION; ENTERITIS; JEJUNI AB Differential sensitivity for the release of PCR-detectable genomic DNA upon boiling in water is reported for 45 Campylobacter jejuni and Campylobacter coli strains isolated in Egypt. All of the strains released PCR-detectable DNA when treated with proteinase K and sodium dodecyl sulfate. When DNA was extracted from these strains by boiling in water, nine (20%) of the strains were PCR negative or resistant to boiling, suggesting the presence of boiling-sensitive and boiling-resistant phenotypes. C1 USN, Med Res Unit 3, Cairo, Egypt. Johns Hopkins Univ, Sch Hyg & Publ Hlth, Baltimore, MD 21205 USA. Univ Texas, Sch Med, Ctr Infect Dis, Houston, TX 77030 USA. RP Mohran, ZS (reprint author), USN, Med Res Unit 3, Res Publicat Branch, PSC 452,Box 5000, FPO, AE 09835 USA. NR 12 TC 23 Z9 24 U1 0 U2 0 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 JAN PY 1998 VL 64 IS 1 BP 363 EP 365 PG 3 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA YP406 UT WOS:000071273600058 PM 9435091 ER PT J AU Anderson, GW Chipman, LE Kub, FJ Park, D Frankel, MY Carruthers, TF Modolo, JA Hobart, KD Katzer, DS AF Anderson, GW Chipman, LE Kub, FJ Park, D Frankel, MY Carruthers, TF Modolo, JA Hobart, KD Katzer, DS TI Gallium arsenide metal-semiconductor-metal photodiodes as optoelectronic mixers for microwave single-sideband modulation SO APPLIED OPTICS LA English DT Article ID PHASE-SHIFTER; ARRAY; RF AB Gallium arsenide (GaAs) metal-semiconductar-metal (MSM) photodetectors have unique propel-ties including high-bandwidth, linearity, and biphase response that make them suitable as mixers and programmable weights for microwave and communications applications. An optical technique for microwave single-sideband modulation that uses GaAs MSM photodiodes as mixers is reported. It uses MSM Schottky photodiodes formed in a GaAs/Al0.3Ga0.7As materials system to detect microwave in-phase and quadrature signals on optical carriers. Modulation of the photodetector bias voltages results in a single-sideband modulation of the microwave signal. Radio frequency and undesired-sideband suppression of 36 and 27 dB, respectively, were achieved. The optical wavelength was 850 nm, and the bandwidth of the photodetectors was greater than or equal to 29 GHz. C1 USN, Res Lab, Washington, DC 20375 USA. RP Anderson, GW (reprint author), USN, Res Lab, Washington, DC 20375 USA. RI Katzer, D. Scott/N-7841-2013 NR 25 TC 3 Z9 3 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 JAN 1 PY 1998 VL 37 IS 1 BP 28 EP 33 DI 10.1364/AO.37.000028 PG 6 WC Optics SC Optics GA YN596 UT WOS:000071185800003 PM 18268556 ER PT J AU Nee, SMF Yoo, C Cole, T Burge, D AF Nee, SMF Yoo, C Cole, T Burge, D TI Characterization for imperfect polarizers under imperfect conditions SO APPLIED OPTICS LA English DT Article ID NEAR-SPECULAR SCATTERING; MUELLER MATRICES; DEPOLARIZATION CRITERION; POLARIZATION; REFLECTION; POLARIMETRY; SURFACE AB The principles for measuring the extinction ratio and transmittance of a polarizer are formulated by use of the principal Mueller matrix, which includes both polarization and depolarization, The extinction ratio is about half of the depolarization, and the contrast is the inverse of the extinction ratio. Errors in the extinction ratio caused by partially polarized incident light and the misalignment of polarizers can be corrected by the devised zone average method and the null method, Used with a laser source, the null method can measure contrasts for very good polarizers. Correct algorithms are established to deduce the depolarization for three comparable polarizers calibrated mutually. These methods are tested with wire-grid polarizers used in the 3-5-mu m wavelength region with a laser source and also a lamp source. The contrasts obtained from both methods agree. (C) 1998 Optical Society of America. C1 USN, Air Warfare Ctr, Weap Div, Res & Technol Grp,Phys Branch, China Lake, CA 93555 USA. RP Nee, SMF (reprint author), USN, Air Warfare Ctr, Weap Div, Res & Technol Grp,Phys Branch, China Lake, CA 93555 USA. NR 21 TC 11 Z9 11 U1 0 U2 2 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 JAN 1 PY 1998 VL 37 IS 1 BP 54 EP 64 DI 10.1364/AO.37.000054 PG 11 WC Optics SC Optics GA YN596 UT WOS:000071185800007 PM 18268560 ER PT J AU Porter, KR Kochel, TJ Wu, SJ Raviprakash, K Phillips, I Hayes, CG AF Porter, KR Kochel, TJ Wu, SJ Raviprakash, K Phillips, I Hayes, CG TI Protective efficacy of a dengue 2 DNA vaccine in mice and the effect of CpG immuno-stimulatory motifs on antibody responses SO ARCHIVES OF VIROLOGY LA English DT Article ID INTRADERMAL GENE IMMUNIZATION AB A recently described DNA vaccine for dengue (DEN) type 2 was shown to elicit high levels of neutralizing antibodies in mice. The vaccine candidate consists of the PreM and 92% of the envelope genes of DEN 2 New Guinea C strain. We further evaluated this DNA vaccine candidate by examining the effect of immune-stimulatory CpG DNA motifs on antibody response and by studying the protective efficacy of the vaccine. The results showed that CpG motifs present in pUC 19 significantly improved the antibody response to a suboptimal dose of 3.1 mu g of the DEN DNA vaccine. In a lethal mouse intracerebral challenge model, the vaccine provided a significant level of protection. Sixty percent of the mice immunized with the DEN DNA vaccine plus pUC 19 survived the challenge compared to only 10% in the control group that received vector plus pUC These studies illustrate that nucleic acid immunization is a viable approach to developing a DEN vaccine and that immune-stimulatory CpG DNA motifs can be used to lower the minimum dose required to produce an antibody response. C1 USN, Med Res Inst, Dept Infect Dis, Bethesda, MD USA. Uniformed Serv Univ Hlth Sci, Dept Med, Bethesda, MD 20814 USA. RP Porter, KR (reprint author), US NAMRU 2, Box 3,Unit 8132, APO, AP 96520 USA. NR 14 TC 66 Z9 72 U1 0 U2 0 PU SPRINGER-VERLAG WIEN PI VIENNA PA SACHSENPLATZ 4-6, PO BOX 89, A-1201 VIENNA, AUSTRIA SN 0304-8608 J9 ARCH VIROL JI Arch. Virol. PY 1998 VL 143 IS 5 BP 997 EP 1003 DI 10.1007/s007050050348 PG 7 WC Virology SC Virology GA ZU454 UT WOS:000074198600013 PM 9645204 ER PT J AU Majde, JA Guha-Thakurta, N Chen, Z Bredow, S Krueger, JM AF Majde, JA Guha-Thakurta, N Chen, Z Bredow, S Krueger, JM TI Spontaneous release of stable viral double-stranded RNA into the extracellular medium by influenza virus-infected MDCK epithelial cells: implications for the viral acute phase response SO ARCHIVES OF VIROLOGY LA English DT Article ID TUMOR-NECROSIS-FACTOR; GENE-EXPRESSION; A VIRUS; INTERFERON; ALPHA; ACTIVATION; CYTOKINES; IFN AB The viral factor responsible for triggering the acute phase response, or 'flu' syndrome, associated with many acute viral infections is not defined. One candidate viral factor is double-stranded RNA (dsRNA) generated during viral replication. In this report we demonstrate by reverse-transcriptase polymerase-chain reaction that nuclease-stable viral RNA was released from influenza-infected MDCK epithelial cells at the time of cell lysis. Removal of virion-associated RNA by ultracentrifugation left equal amounts of positive-and negative-strand viral RNA in the medium that resisted degradation by endogenous RNase in the medium and by exogenous RNase added prior to phenol extraction. These data are the first demonstration that viral RNA with characteristics of dsRNA is spontaneously released from dying influenza virus-infected cells, and thus is available to amplify cytokine induction and contribute to systemic disease. C1 Off Naval Res, Div Med Sci & Technol 341, Arlington, VA 22217 USA. Univ Tennessee, Sch Med, Dept Physiol & Biophys, Memphis, TN 38104 USA. Washington State Univ, Coll Vet Med, Dept Vet & Comparat Anat Pharmacol & Physiol, Pullman, WA 99164 USA. Massachusetts Gen Hosp, Ctr Mol Imaging Res, Charlestown, MA USA. RP Majde, JA (reprint author), Off Naval Res, Div Med Sci & Technol 341, 800 N Quincy St, Arlington, VA 22217 USA. FU NICHD NIH HHS [HD36520] NR 23 TC 44 Z9 44 U1 0 U2 4 PU SPRINGER-VERLAG WIEN PI VIENNA PA SACHSENPLATZ 4-6, PO BOX 89, A-1201 VIENNA, AUSTRIA SN 0304-8608 J9 ARCH VIROL JI Arch. Virol. PY 1998 VL 143 IS 12 BP 2371 EP 2380 DI 10.1007/s007050050467 PG 10 WC Virology SC Virology GA 166PR UT WOS:000078586500008 PM 9930193 ER PT B AU Sengupta, K AF Sengupta, K BE Hoadley, ED Benbasat, I TI The representation and use of process knowledge in the design of information systems SO ASSOCIATION FOR INFORMATION SYSTEMS PROCEEDINGS OF THE AMERICAS CONFERENCE ON INFORMATION SYSTEMS LA English DT Proceedings Paper CT 4th AIS Americas Conference on Information Systems CY AUG 14-16, 1998 CL BALTIMORE, MD SP Assoc Informat Syst AB The design of an information system entails making a series of interdependent decisions. These decisions result in the creation of design artifacts such as drawings, prototypes, and design documentation. Current approaches toward system design focus on the creation of the artifacts, rather than capturing the accompanying process knowledge, such as the rationale underlying their design. The loss of process knowledge can frequently cause problems downstream, e.g., in subsequent use or modification of the artifact. In recognition of the value of process knowledge in the system development lifecycle, much work has been done in The recent past on developing methods for the capture and use of process knowledge. Many of these methods have been incorporated in recent versions of CASE tools. This tutorial will provide an overview of the theories underlying the representation and use of process knowledge, the principal methods employed, and the implementation of the methods in CASE tools. We will also discuss factors that constrain the capture and use of process knowledge in organizational settings. The material covered in the tutorial will be illustrated through a stylized example, abstracted from an actual design situation. C1 USN, Postgrad Sch, Monterey, CA 93943 USA. RP Sengupta, K (reprint author), USN, Postgrad Sch, Monterey, CA 93943 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ASSOCIATION INFORMATION SYSTEMS PI ATLANTA PA P.O. BOX 2712, ATLANTA, GA 30301-2712 USA PY 1998 BP 1136 EP 1137 PG 2 WC Business; Business, Finance; Computer Science, Information Systems; Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering; Computer Science, Theory & Methods SC Business & Economics; Computer Science GA BM34K UT WOS:000078432000388 ER PT S AU Purdy, W Coffey, S Barnds, WJ Kelm, B Davis, M AF Purdy, W Coffey, S Barnds, WJ Kelm, B Davis, M BE Hoots, FR Kaufman, B Cefola, PJ Spencer, DB TI Tips: Results of a Tethered satellite experiment SO ASTRODYNAMICS 1997 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT AAS/AIAA Astrodynamics Conference CY AUG 04-07, 1997 CL SUN VALLEY, ID SP Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut AB This paper presents the results of the Tether Physics and Survivability (TiPS) experiment, We provide a description of new analytical tools and methodologies developed for determining the dynamics of the system, A year's worth of laser, radar and optical tracking are combined to provide the history of the librational and rotational motion. The most significant finding from the experiment was that the attitude and rotational motions have damped significantly since initial deployment. A number of tether dynamics specialists have been enlisted to correlate the observed dynamics with theoretical models. In turn, enhancements in the tether models are being made as a result of the TiPS data, The results of the TiPS experiment demonstrates the predictability, stability and robustness of tether systems and hint at tethers' potential for space applications. C1 USN, Res Lab, Washington, DC 20375 USA. RP Purdy, W (reprint author), USN, Res Lab, Code 8233,4555 Overlook Ave SW, Washington, DC 20375 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 USA SN 1081-6003 BN 0-87703-441-9 J9 ADV ASTRONAUT SCI PY 1998 VL 97 BP 3 EP 23 PN 1-2 PG 21 WC Engineering, Aerospace; Astronomy & Astrophysics; Meteorology & Atmospheric Sciences; Remote Sensing SC Engineering; Astronomy & Astrophysics; Meteorology & Atmospheric Sciences; Remote Sensing GA BK64Z UT WOS:000072955800001 ER PT S AU Zedd, MF AF Zedd, MF BE Hoots, FR Kaufman, B Cefola, PJ Spencer, DB TI Experiments in tether dynamics planned for ATEX's flight SO ASTRODYNAMICS 1997 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT AAS/AIAA Astrodynamics Conference CY AUG 04-07, 1997 CL SUN VALLEY, ID SP Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut AB Following the successful one year operation of the Tether Physics and Survivability (TiPS) satellite, the Naval Research Laboratory (NRL) plans to fly a second tethered satellite system in the first half of 1998. The Advanced Tether Experiment (ATEx) is designed to extend our knowledge of control and survivability of tethered space systems. Experiments in active control will study deployment dynamics via a constant-speed motor and utilization of both in-plane and cross-plane thrusters to excite and arrest librations. Additionally, ATEx will investigate the survivability of long-life tether materials. This paper will describe the ATEx payload carried by the Space Technology Experiment (STEX) spacecraft and preview the anticipated flight experiments as shown by the results of two tethered system dynamics simulations. C1 USN, Res Lab, Washington, DC 20375 USA. RP Zedd, MF (reprint author), USN, Res Lab, Code 8233,4555 Overlook Ave SW, Washington, DC 20375 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 USA SN 1081-6003 BN 0-87703-441-9 J9 ADV ASTRONAUT SCI PY 1998 VL 97 BP 25 EP 44 PN 1-2 PG 20 WC Engineering, Aerospace; Astronomy & Astrophysics; Meteorology & Atmospheric Sciences; Remote Sensing SC Engineering; Astronomy & Astrophysics; Meteorology & Atmospheric Sciences; Remote Sensing GA BK64Z UT WOS:000072955800002 ER PT S AU Gilbreath, GC Schumacher, PW Davis, MA Lydick, ED Anderson, JM AF Gilbreath, GC Schumacher, PW Davis, MA Lydick, ED Anderson, JM BE Hoots, FR Kaufman, B Cefola, PJ Spencer, DB TI Calibrating the naval space surveillance pence using Satellite Laser Ranging SO ASTRODYNAMICS 1997 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT AAS/AIAA Astrodynamics Conference CY AUG 04-07, 1997 CL SUN VALLEY, ID SP Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut AB An experiment is described in which tile NAVSPACECOM Fence Receivers are calibrated using Satellite Laser Ranging. We believe these are the first results presented using this method of calibration and they show the feasibility of the method as well as illustrate its powerful potential as a sensor diagnostic using this approach. C1 USN, Res Lab, Electroopt Technol Sect, Washington, DC 20375 USA. RP Gilbreath, GC (reprint author), USN, Res Lab, Electroopt Technol Sect, Code 8123, Washington, DC 20375 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 USA SN 1081-6003 BN 0-87703-441-9 J9 ADV ASTRONAUT SCI PY 1998 VL 97 BP 403 EP 416 PN 1-2 PG 14 WC Engineering, Aerospace; Astronomy & Astrophysics; Meteorology & Atmospheric Sciences; Remote Sensing SC Engineering; Astronomy & Astrophysics; Meteorology & Atmospheric Sciences; Remote Sensing GA BK64Z UT WOS:000072955800025 ER PT S AU Gilbreath, GC Rolsma, PB Kessel, RA Georges, JA AF Gilbreath, GC Rolsma, PB Kessel, RA Georges, JA BE Hoots, FR Kaufman, B Cefola, PJ Spencer, DB TI Laser ranging target considerations for LEO spacecraft SO ASTRODYNAMICS 1997 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT AAS/AIAA Astrodynamics Conference CY AUG 04-07, 1997 CL SUN VALLEY, ID SP Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut AB This paper describes a design for a robust and compact retroreflector array configuration for a LEO spacecraft for use in laser radar. The particular configuration is a hemisphere of consisting of 22 one centimeter retroreflectors. The necessary numerical methods required in support of design analysis are also developed. Unique in our treatment is bench-level experimental results for measurements of the scaled far-field intensity distribution for an array. Experimental data is compared to design analysis. C1 USN, Res Lab, Electroopt Technol Sect, Washington, DC 20375 USA. RP Gilbreath, GC (reprint author), USN, Res Lab, Electroopt Technol Sect, Code 8123, Washington, DC 20375 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 USA SN 1081-6003 BN 0-87703-441-9 J9 ADV ASTRONAUT SCI PY 1998 VL 97 BP 417 EP 433 PN 1-2 PG 17 WC Engineering, Aerospace; Astronomy & Astrophysics; Meteorology & Atmospheric Sciences; Remote Sensing SC Engineering; Astronomy & Astrophysics; Meteorology & Atmospheric Sciences; Remote Sensing GA BK64Z UT WOS:000072955800026 ER PT S AU Picone, JM Hedin, AE Coffey, SL Lean, J Drob, DP Neal, H Melendez-Alvira, DJ Meier, RR Mariska, JT AF Picone, JM Hedin, AE Coffey, SL Lean, J Drob, DP Neal, H Melendez-Alvira, DJ Meier, RR Mariska, JT BE Hoots, FR Kaufman, B Cefola, PJ Spencer, DB TI The Naval Research Laboratory program on empirical models of the neutral upper atmosphere SO ASTRODYNAMICS 1997 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT AAS/AIAA Astrodynamics Conference CY AUG 04-07, 1997 CL SUN VALLEY, ID SP Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut AB The Naval Research Laboratory (NRL) has embarked on an exploratory development program to acquire and upgrade empirical models of the neutral upper atmosphere (thermosphere and upper mesosphere), developed originally by Dr. A. E. Hedin, now retired from NASA. The program focus is the Mass Spectrometer - Incoherent Scatter Radar (MSIS) model of composition and temperature. The present version (MSISE-90) combines ground-based radar, satellite, and rocket measurements made primarily during the period 1965 - 83. Continuation of this work is essential, since future operational and experimental satellite systems will provide extensive data that will enhance predictions by MSIS. We are now ingesting additional data sets into a new version (MSISE-98), including for the first time the drag data of Jacchia and others. To further enhance MSIS, we have also produced a new full disk proxy for the solar driver of thermospheric variability, based on fluctuations of the Sun's chromosphere. A key feature of this program is a new NRL system to test neutral density models for orbital tracking and prediction. C1 USN, Res Lab, Washington, DC 20375 USA. RP Picone, JM (reprint author), USN, Res Lab, 4555 Overlook Ave SW, Washington, DC 20375 USA. RI Drob, Douglas/G-4061-2014 OI Drob, Douglas/0000-0002-2045-7740 NR 0 TC 6 Z9 6 U1 0 U2 2 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 USA SN 1081-6003 BN 0-87703-441-9 J9 ADV ASTRONAUT SCI PY 1998 VL 97 BP 515 EP 527 PN 1-2 PG 13 WC Engineering, Aerospace; Astronomy & Astrophysics; Meteorology & Atmospheric Sciences; Remote Sensing SC Engineering; Astronomy & Astrophysics; Meteorology & Atmospheric Sciences; Remote Sensing GA BK64Z UT WOS:000072955800032 ER PT S AU Neal, HL Coffey, SL Knowles, S AF Neal, HL Coffey, SL Knowles, S BE Hoots, FR Kaufman, B Cefola, PJ Spencer, DB TI Maintaining the space object catalog with special perturbations SO ASTRODYNAMICS 1997 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT AAS/AIAA Astrodynamics Conference CY AUG 04-07, 1997 CL SUN VALLEY, ID SP Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut AB This paper examines the benefits and problems associated with maintaining a space object catalog using numerical integration, commonly referred to as special perturbations, to propagate the orbits. Although special perturbations requires significant computational resources, it offers advantages in accuracy and in the flexibility of force modeling over the analytic propagation methods currently in use. The computational requirement was met by distributing the work load across multiple processors. The catalog maintenance program was implemented in a distributed parallel processing environment called Parallel Virtual Machine (PVM). We compare the accuracy of special perturbations versus analytic methods and examine the effects of orbit type, observation density, and other factors on special perturbations catalog maintenance. C1 USN, Res Lab, GRC Int, Washington, DC 20375 USA. RP Neal, HL (reprint author), USN, Res Lab, GRC Int, Code 8233,4555 Overlook Ave SW, Washington, DC 20375 USA. NR 0 TC 3 Z9 3 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 USA SN 1081-6003 BN 0-87703-441-9 J9 ADV ASTRONAUT SCI PY 1998 VL 97 BP 1349 EP 1360 PN 1-2 PG 12 WC Engineering, Aerospace; Astronomy & Astrophysics; Meteorology & Atmospheric Sciences; Remote Sensing SC Engineering; Astronomy & Astrophysics; Meteorology & Atmospheric Sciences; Remote Sensing GA BK64Z UT WOS:000072955800083 ER PT S AU Neta, B AF Neta, B BE Hoots, FR Kaufman, B Cefola, PJ Spencer, DB TI Parallel version of special perturbations orbit propagator SO ASTRODYNAMICS 1997 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT AAS/AIAA Astrodynamics Conference CY AUG 04-07, 1997 CL SUN VALLEY, ID SP Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut AB Parallelization can be achieved by either control or domain decomposition. The latter was tried for analytic (by Neta et al.) and semianalytic (by Wallace) propagators. Neal and Coffey will discuss the domain decomposition for special perturbations. The control decomposition idea is inefficient for analytic propagators (Neta et al.), because the computation time is too short. In this paper, we discuss a control decomposition approach to parallelize a numerical orbit propagator which is more computationally intensive. C1 USN, Postgrad Sch, Dept Math, Monterey, CA 93943 USA. RP Neta, B (reprint author), USN, Postgrad Sch, Dept Math, Code MA-ND, Monterey, CA 93943 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 USA SN 1081-6003 BN 0-87703-441-9 J9 ADV ASTRONAUT SCI PY 1998 VL 97 BP 1361 EP 1369 PN 1-2 PG 9 WC Engineering, Aerospace; Astronomy & Astrophysics; Meteorology & Atmospheric Sciences; Remote Sensing SC Engineering; Astronomy & Astrophysics; Meteorology & Atmospheric Sciences; Remote Sensing GA BK64Z UT WOS:000072955800084 ER PT S AU Segerman, AM Coffey, SL AF Segerman, AM Coffey, SL BE Hoots, FR Kaufman, B Cefola, PJ Spencer, DB TI Ephemeris compression using multiple Fourier series SO ASTRODYNAMICS 1997 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT AAS/AIAA Astrodynamics Conference CY AUG 04-07, 1997 CL SUN VALLEY, ID SP Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut AB An ephemeris compression method has been developed which uses multiple Fourier series, The compression itself is performed upon the Cartesian residuals which result from differencing the ephemeris with an ephemeris generated by a widely-used analytical propagator, such as PPT. An accurate estimate of the ephemeris may then be generated by reconstructing the residuals from the Fourier coefficients and superposing these;with the analytical propagator's ephemeris. Statistical results from testing the method with the satellite catalog are presented. C1 USN, Res Lab, GRC Int Inc, Washington, DC 20375 USA. RP Segerman, AM (reprint author), USN, Res Lab, GRC Int Inc, Code 8233,4555 Overlook Ave SW, Washington, DC 20375 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 USA SN 1081-6003 BN 0-87703-441-9 J9 ADV ASTRONAUT SCI PY 1998 VL 97 BP 1371 EP 1386 PN 1-2 PG 16 WC Engineering, Aerospace; Astronomy & Astrophysics; Meteorology & Atmospheric Sciences; Remote Sensing SC Engineering; Astronomy & Astrophysics; Meteorology & Atmospheric Sciences; Remote Sensing GA BK64Z UT WOS:000072955800085 ER PT S AU Minter, CF Cicci, DA AF Minter, CF Cicci, DA BE Hoots, FR Kaufman, B Cefola, PJ Spencer, DB TI Improvements in Mars gravity field determination using ridge-type estimation methods SO ASTRODYNAMICS 1997 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT AAS/AIAA Astrodynamics Conference CY AUG 04-07, 1997 CL SUN VALLEY, ID SP Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut AB The-objective of this research was to improve the accuracy of the Jet Propulsion Laboratory's Mars gravity field model, Mars50c, through the use of ridge-type estimation methods. These advanced parameter estimation techniques were applied to the calculation of GM and a (50x50) field of harmonic coefficients, representing the gravitational potential of Mars. Data used in this analysis were derived from Viking and Mariner 9 Doppler tracking data. Calculation of the gravity field coefficients involves solving a large, ill-conditioned system of linear equations, whose solution leads to erroneous estimates if not augmented by appropriate a priori information. In calculating Mars50c, an a priori covariance was used in order to provide a set of constraints on the gravity field solution. This study involved the use of ridge-type estimation methods to optimally weight a set of a priori constraints based upon Kaula's Rule in order to obtain more accurate estimates. The computed gravity field, denoted AUMGM9, was. compared to Mars50c on the basis of total variance of the solution and residual sum of squares. Analysis of the results show that through the use of ridge-type estimation methods, AUMGM9 provides more accurate gravity field coefficients than does Mars50c. C1 USN, Ctr Surface Warfare, Dahlgren, VA 22448 USA. RP Minter, CF (reprint author), USN, Ctr Surface Warfare, Code T-13,17320 Dahlgren Rd, Dahlgren, VA 22448 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 USA SN 1081-6003 BN 0-87703-441-9 J9 ADV ASTRONAUT SCI PY 1998 VL 97 BP 1549 EP 1566 PN 1-2 PG 18 WC Engineering, Aerospace; Astronomy & Astrophysics; Meteorology & Atmospheric Sciences; Remote Sensing SC Engineering; Astronomy & Astrophysics; Meteorology & Atmospheric Sciences; Remote Sensing GA BK64Z UT WOS:000072955800097 ER PT S AU Soyka, MT Middour, JW Binning, PW Pickard, H Fein, J AF Soyka, MT Middour, JW Binning, PW Pickard, H Fein, J BE Hoots, FR Kaufman, B Cefola, PJ Spencer, DB TI The Naval Research Laboratory's orbit/covariance estimation and analysis software: OCEAN SO ASTRODYNAMICS 1997 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT AAS/AIAA Astrodynamics Conference CY AUG 04-07, 1997 CL SUN VALLEY, ID SP Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut AB The new precise orbit determination software system, OCEAN, developed at NRL, is described. Sub-meter level orbit determination results are presented. The J2000.0 based system is capable of simultaneously processing multiple satellites, ground stations, and measurement types in manual or automatic mode. Included in the system are a batch processor, a Kalman filter and backward smoother, and orbit conversion utilities. All are designed to function over the year 2000 rollover. The batch processor processes thirteen measurement types to solve for absolute states, while the filter-smoother processes ranging, GPS pseudorange and carrier phase differential measurement types to solve for absolute and/or relative states. C1 USN, Res Lab, Astrodynam & Space Applicat Off, Washington, DC 20375 USA. RP Soyka, MT (reprint author), USN, Res Lab, Astrodynam & Space Applicat Off, Code 8103,4555 Overlook Ave SW, Washington, DC 20375 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 USA SN 1081-6003 BN 0-87703-441-9 J9 ADV ASTRONAUT SCI PY 1998 VL 97 BP 1567 EP 1586 PN 1-2 PG 20 WC Engineering, Aerospace; Astronomy & Astrophysics; Meteorology & Atmospheric Sciences; Remote Sensing SC Engineering; Astronomy & Astrophysics; Meteorology & Atmospheric Sciences; Remote Sensing GA BK64Z UT WOS:000072955800098 ER PT S AU Park, SY Elder, JT Ross, IM AF Park, SY Elder, JT Ross, IM BE Hoots, FR Kaufman, B Cefola, PJ Spencer, DB TI Minimum delta-V for deflecting Earth-crossing asteroids SO ASTRODYNAMICS 1997 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT AAS/AIAA Astrodynamics Conference CY AUG 04-07, 1997 CL SUN VALLEY, ID SP Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut AB We present a formulation of a finite-dimensional optimization problem associated with the deflection of Earth-Crossing Asteroids, The performance measure is minimizing the delta-V requirement for achieving a minimum target separation distance, A number of astrodynamical constraints are identified and modeled, The constrained optimization problem is numerically solved using a sequential quadratic programming method. Our numerical analysis indicates that the minimum delta-V requirement is not a monotonically decreasing function of the warning time; rather, there is a finer structure associated with the orbital period of the colliding asteroid, Computations performed for the asteroid Toutatis also illustrate these points. C1 USN, Postgrad Sch, Dept Aeronaut & Astronaut, Monterey, CA 93943 USA. RP Park, SY (reprint author), USN, Postgrad Sch, Dept Aeronaut & Astronaut, Code AA-PR,699 Dyer Rd,Room 137, Monterey, CA 93943 USA. RI Park, Sang-Young/F-5989-2013 NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 USA SN 1081-6003 BN 0-87703-441-9 J9 ADV ASTRONAUT SCI PY 1998 VL 97 BP 1969 EP 1978 PN 1-2 PG 10 WC Engineering, Aerospace; Astronomy & Astrophysics; Meteorology & Atmospheric Sciences; Remote Sensing SC Engineering; Astronomy & Astrophysics; Meteorology & Atmospheric Sciences; Remote Sensing GA BK64Z UT WOS:000072955800120 ER PT S AU Hutter, DJ Elias, NM Hummel, CA AF Hutter, DJ Elias, NM Hummel, CA BE Reasenberg, RD TI First astrometric results from the NPOI SO ASTRONOMICAL INTERFEROMETRY, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Astronomical Interferometry CY MAR 20-24, 1998 CL KONA, HI SP SPIE, European So Observ DE optical interferometry NPOI; wide-angle astrometry; metrology AB The Navy Prototype Optical Interferometer (NPOI) has been routinely used since 1996 for observations of stellar diameters and limb darkening, and for the imaging of binary stars, Here, we present the first results of, and future goals for, wide-angle astrometric observations from the NPOI. C1 USN Observ, Washington, DC 20392 USA. RP Hutter, DJ (reprint author), USN Observ, Flagstaff Stn, POB 1149, Flagstaff, AZ 86002 USA. NR 0 TC 5 Z9 5 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 0-8194-2797-7 J9 P SOC PHOTO-OPT INS PY 1998 VL 3350 BP 452 EP 460 DI 10.1117/12.317110 PN 1-2 PG 9 WC Engineering, Aerospace; Astronomy & Astrophysics; Optics SC Engineering; Astronomy & Astrophysics; Optics GA BL55C UT WOS:000075850300049 ER PT S AU Armstrong, JT Mozurkewich, D Pauls, TA Hajian, AR AF Armstrong, JT Mozurkewich, D Pauls, TA Hajian, AR BE Reasenberg, RD TI Bootstrapping the NPOI: Keeping long baselines in phase by tracking fringes on short baselines SO ASTRONOMICAL INTERFEROMETRY, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Astronomical Interferometry CY MAR 20-24, 1998 CL KONA, HI SP SPIE, European So Observ DE interferometry AB The high-spatial-frequency fringes that contain detailed information about a stellar image are generally too weak to track. The Navy Prototype Optical interferometer (NPOI) is the first interferometer to measure these fringes with the techniques of phase bootstrapping-the use of fringe tracking on two short baselines AB and BC to keep a longer baseline AC phased up-and wavelength bootstrapping-the use of fringe tracking at long wavelengths to keep the long baseline phased up at short wavelengths. We demonstrate the utility of phase and wavelength bootstrapping with the NPOI observations of stellar limb darkening of beta Cancri (theta(LD) = 5.20 mas) of Pauls et al.(1) in these proceedings. The NPOI baselines and wavelength coverage were 19, 22, and 38 m and lambda 4.50 to lambda 850 nm. For lambda < 675 nm, the 37 m baseline samples the uv plane beyond the first null of the Airy disk. C1 USN, Res Lab, Remote Sensing Div, Washington, DC 20375 USA. RP Armstrong, JT (reprint author), USN, Res Lab, Remote Sensing Div, 4555 Overlook Ave SW, Washington, DC 20375 USA. NR 0 TC 16 Z9 16 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 0-8194-2797-7 J9 P SOC PHOTO-OPT INS PY 1998 VL 3350 BP 461 EP 466 DI 10.1117/12.317111 PN 1-2 PG 6 WC Engineering, Aerospace; Astronomy & Astrophysics; Optics SC Engineering; Astronomy & Astrophysics; Optics GA BL55C UT WOS:000075850300050 ER PT S AU Pauls, TA Mozurkewich, D Armstrong, JT Hummel, CA Benson, JA Hajian, A AF Pauls, TA Mozurkewich, D Armstrong, JT Hummel, CA Benson, JA Hajian, A BE Reasenberg, RD TI Observations of stellar limb darkening with the Navy Prototype Optical Interferometer SO ASTRONOMICAL INTERFEROMETRY, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Astronomical Interferometry CY MAR 20-24, 1998 CL KONA, HI SP SPIE, European So Observ DE optical interferometry; stellar limb darkening; stellar diameters; phase bootstrapping AB We present results of an on-going program to measure limb-darkened angular diameters of late-type giant stars using the Navy Prototype Optical Interferometer (NPOI). Observing with three elements of the NPOI and using twenty spectral channels covering the wavelength range from 520 nm to 850 nm we are able to extend the spatial frequency coverage beyond the first null in the stellar visibilty function for a number of K giants. These observations make use of the technique of phase bootstrapping in which the shorter baselines with high visibilites are used to keep the longer baselines in phase. The data are inconsistent with a uniform brightness stellar disk. Adopting a particular limb-darkening model enables us to derive a angular diameter with high precision (one part in 1000). The total uncertainty is dominated by our knowledge of the wavelength scale (one part in 100). These observations also include measurments of the closure phase, which shows a jump of 180 degrees at the position of the first null in the visibilty amplitude. This is the first time a non-zero closure phase has been measured on a single star with a separate element optical interferometer. C1 USN, Res Lab, Washington, DC 20375 USA. RP Pauls, TA (reprint author), USN, Res Lab, Code 7210, Washington, DC 20375 USA. NR 0 TC 5 Z9 5 U1 1 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 0-8194-2797-7 J9 P SOC PHOTO-OPT INS PY 1998 VL 3350 BP 467 EP 470 DI 10.1117/12.317112 PN 1-2 PG 4 WC Engineering, Aerospace; Astronomy & Astrophysics; Optics SC Engineering; Astronomy & Astrophysics; Optics GA BL55C UT WOS:000075850300051 ER PT S AU Mozurkewich, D AF Mozurkewich, D BE Reasenberg, RD TI Atmospheric power spectra SO ASTRONOMICAL INTERFEROMETRY, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Astronomical Interferometry CY MAR 20-24, 1998 CL KONA, HI SP SPIE, European So Observ DE optical interferometry; NPOI; atmospheric turbulence; outer scales AB As a fringe tracking stellar interferometer, the NPOI routinely determines rime series of fringe motion and provides the only currently available simultaneous multi-baseline atmospheric turbulence data. We have used these time series to determine properties of atmospheric turbulence at the Anderson Mesa astronomical site near Flagstaff AZ. The shapes of the temporal power spectra imply an infinite outer scale. However: the total atmospheric power is significantly less than expected. This implies a very short outer scale, despite the shape of the spectra, The data are presented and discussed. C1 USN, Res Lab, Remote Sensing Div, Washington, DC 20375 USA. RP Mozurkewich, D (reprint author), USN, Res Lab, Remote Sensing Div, 4555 Overlook Ave SW, Washington, DC 20375 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 0-8194-2797-7 J9 P SOC PHOTO-OPT INS PY 1998 VL 3350 BP 478 EP 482 DI 10.1117/12.317115 PN 1-2 PG 5 WC Engineering, Aerospace; Astronomy & Astrophysics; Optics SC Engineering; Astronomy & Astrophysics; Optics GA BL55C UT WOS:000075850300053 ER PT S AU Hummel, CA AF Hummel, CA BE Reasenberg, RD TI Images of spectroscopic binaries with the navy prototype optical interferometer SO ASTRONOMICAL INTERFEROMETRY, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Astronomical Interferometry CY MAR 20-24, 1998 CL KONA, HI SP SPIE, European So Observ DE optical interferometry; NPOI; spectroscopic binaries; imaging AB We discuss reduction, calibration, and imaging of data from the multi-baseline, multi-channel Navy Prototype Optical Interferometer (NPOI). Images utilizing closure phases are presented for Mizar A and several other binaries on scales from a few milliarcseconds (mas) to several tens of mas. A complete orbital solution has been obtained for Mizar A with a median residual of 0.08 mas. A correlation between the visibility amplitude and a temporal seeing indicator is used to calibrate the amplitudes with an error of about 15%, closure phase offsets vary slowly with time and can be calibrated with an error of a few degrees. However, unmodeled visibility variations remain at a level above the design goals. Earth rotation aperture synthesis is very fast with the 520 nm to 850 nm wavelength coverage of the NPOI, so that as few as four scans result in images with dynamic range of 100:1 of simple binaries with negligible color difference between the components. Mapping was done in AIPS, a package developed for radio interferometry with the VLA and VLBI, but fundamental differences between radio and optical data are the availability from NPOI of an independently computed triple product of the complex visibilities, and the availability of the square of the visibility amplitude on single baselines. The latter quantity needs bias correction, whereas the former is practically unbiased if independent detectors contribute to the signal. Broad band optical interferometry mapping algorithms therefore present a new development challenge. C1 USN Observ, Washington, DC 20392 USA. RP Hummel, CA (reprint author), USN Observ, 3450 Massachusetts Ave, Washington, DC 20392 USA. 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 0-8194-2797-7 J9 P SOC PHOTO-OPT INS PY 1998 VL 3350 BP 483 EP 492 DI 10.1117/12.317116 PN 1-2 PG 10 WC Engineering, Aerospace; Astronomy & Astrophysics; Optics SC Engineering; Astronomy & Astrophysics; Optics GA BL55C UT WOS:000075850300054 ER PT S AU Benson, JA Mozurkewich, D Jefferies, SM AF Benson, JA Mozurkewich, D Jefferies, SM BE Reasenberg, RD TI Active optical fringe tracking at the NPOI SO ASTRONOMICAL INTERFEROMETRY, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Astronomical Interferometry CY MAR 20-24, 1998 CL KONA, HI SP SPIE, European So Observ DE optical interferometry; fringe tracking; closure phase AB The Navy Prototype Optical Interferometer, NPOI, is routinely used to measure visibility amplitudes and closure phase for stellar objects at optical wavelengths (e.g., Benson et al.,(1) Hajian et al.(2)). In this poster we describe the fringe data collection aspects and the real time algorithm that enables us to actively track fringes with the instrument. For a detailed description of the overall instrument see Armstrong et al..(3) C1 USN Observ, Flagstaff, AZ USA. RP Benson, JA (reprint author), USN Observ, POB 1149, Flagstaff, AZ USA. NR 0 TC 12 Z9 12 U1 1 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 0-8194-2797-7 J9 P SOC PHOTO-OPT INS PY 1998 VL 3350 BP 493 EP 496 DI 10.1117/12.317117 PN 1-2 PG 4 WC Engineering, Aerospace; Astronomy & Astrophysics; Optics SC Engineering; Astronomy & Astrophysics; Optics GA BL55C UT WOS:000075850300055 ER PT S AU Clark, JH Ha, L Mozurkewich, D Armstrong, JT AF Clark, JH Ha, L Mozurkewich, D Armstrong, JT BE Reasenberg, RD TI Design of the long delay lines for the navy prototype optical interferometer SO ASTRONOMICAL INTERFEROMETRY, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Astronomical Interferometry CY MAR 20-24, 1998 CL KONA, HI SP SPIE, European So Observ DE optical interferometry; delay lines; vacuum; control AB We have designed a method for introducing the large delays needed for the full 437 meter baseline imaging subarray of the Navy Prototype Optical Interferometer (NPOI). Long delay lines (LDLs) will introduce delay in discrete 29 meter increments for each of the six array elements. In conjunction with the 35 meters of delay from the continuously-variable fast delay lines, the LDLs will allow fringe tracking for all baselines at any position on the sky. We present the mechanical layout, alignment and vacuum design of the LDLs. C1 USN Observ, Univ Space Res Assoc, USNO, NRL,Opt Interferometer Project,Dept Astron, Washington, DC 20392 USA. RP Clark, JH (reprint author), USN Observ, Univ Space Res Assoc, USNO, NRL,Opt Interferometer Project,Dept Astron, 3450 Massachusetts Ave NW, Washington, DC 20392 USA. NR 0 TC 15 Z9 15 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 0-8194-2797-7 J9 P SOC PHOTO-OPT INS PY 1998 VL 3350 BP 497 EP 504 DI 10.1117/12.317118 PN 1-2 PG 8 WC Engineering, Aerospace; Astronomy & Astrophysics; Optics SC Engineering; Astronomy & Astrophysics; Optics GA BL55C UT WOS:000075850300056 ER PT S AU Johnston, KY AF Johnston, KY BE Reasenberg, RD TI The Navy Prototype Optical Interferometer SO ASTRONOMICAL INTERFEROMETRY, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Astronomical Interferometry CY MAR 20-24, 1998 CL KONA, HI SP SPIE, European So Observ DE interferometer; subarrays; array AB The Navy Prototype Optical Interferometer contains two major subarrays: one for imaging the surface of stars, the other for measuring the precise positions of bright stars. In order to image the surface of stars, six 50 cm elements which can be reconfigured to sample many spatial frequencies using 32 spectral channels equally spaced in wavenumber between 450 and 850 nanometers. The imaging array elements are distributed on a "Y" with a maximum spacing for imaging of 437 m, yielding a spatial resolution of 0.2 mas. The positions of stars will be measured using four fixed 50 cm siderostats with element spacings from 19 to 38 meters. The delay line compensation and beam paths are in vacuum to eliminate the effects of atmospheric dispersion. The astrometric goal is an accuracy of 2 mas over wide angles. C1 USN Observ, Washington, DC 20390 USA. RP Johnston, KY (reprint author), USN Observ, Washington, DC 20390 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 0-8194-2797-7 J9 P SOC PHOTO-OPT INS PY 1998 VL 3350 BP 941 EP 946 DI 10.1117/12.317161 PN 1-2 PG 6 WC Engineering, Aerospace; Astronomy & Astrophysics; Optics SC Engineering; Astronomy & Astrophysics; Optics GA BL55C UT WOS:000075850300103 ER PT J AU Henden, AA Stone, RC AF Henden, AA Stone, RC TI New variables in the Sloan Digital Sky Survey calibration fields SO ASTRONOMICAL JOURNAL LA English DT Article DE Cepheids; stars, variables, other ID PHOTOMETRIC STANDARD STARS; CELESTIAL EQUATOR AB The US Naval Observatory 0.2 m Flagstaff Astrometric Scanning Transit Telescope was used to obtain astrometric information in 16 equatorial fields in support of the Sloan Digital Sky Survey. Each field is approximately 7.degrees 6 x 3.degrees 2 in size and was scanned similar to 10 times with overlapping CCD strip scans; star positions accurate to +/-50 mas in each coordinate and magnitudes good to +/-0.011 mag were determined. As an ancillary project, this database was searched for new variables, and the results of that search are presented here, Approximately 1500 new variables have been discovered, and accurate coordinates for similar to 100 previously identified variables and suspected variables are given. C1 USN Observ, Flagstaff Stn, Flagstaff, AZ 86002 USA. RP Henden, AA (reprint author), USN Observ, Flagstaff Stn, POB 1149, Flagstaff, AZ 86002 USA. NR 14 TC 21 Z9 22 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5801 S ELLIS AVENUE, CHICAGO, IL 60637 USA SN 0004-6256 J9 ASTRON J JI Astron. J. PD JAN PY 1998 VL 115 IS 1 BP 296 EP 302 DI 10.1086/300174 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA YQ454 UT WOS:000071389200027 ER PT J AU Kaplan, GH AF Kaplan, GH TI High-precision algorithms for astrometry: A comparison of two approaches SO ASTRONOMICAL JOURNAL LA English DT Article DE astrometry; catalogs; reference systems; techniques, interferometric ID PICOSECOND ACCURACY; REDUCTION; APPARENT; PLACES; STARS AB This paper discusses the correspondence between two approaches to astrometric observational reductions: the approach based on angular observables used for optical observations, and the approach based on the interferometric delay observable used for very long baseline radio interferometry (VLBI) observations. A procedure is presented by which VLBI algorithms can be used for optical observations. This scheme can help to guarantee consistent treatment of observational results in the two regimes. Differences between angle-and delay-based algorithms in current use are shown to be less than 1 mu as. However, the physical models used as the bases for the algorithms must be improved to reach external accuracies at such levels. C1 USN Observ, Washington, DC 20392 USA. RP Kaplan, GH (reprint author), USN Observ, 3450 Massachusetts Ave NW, Washington, DC 20392 USA. NR 41 TC 5 Z9 5 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5801 S ELLIS AVENUE, CHICAGO, IL 60637 USA SN 0004-6256 J9 ASTRON J JI Astron. J. PD JAN PY 1998 VL 115 IS 1 BP 361 EP 372 DI 10.1086/300189 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA YQ454 UT WOS:000071389200035 ER PT J AU Schalinski, C Johnston, KJ Witzel, A Waltman, EB Umana, G Pavelin, PE Ghigo, FD Venturi, T Mantovani, F Foley, AR Spencer, RE Davis, RJ AF Schalinski, C Johnston, KJ Witzel, A Waltman, EB Umana, G Pavelin, PE Ghigo, FD Venturi, T Mantovani, F Foley, AR Spencer, RE Davis, RJ TI VLBI monitoring of the complex jet of Cygnus X-3 during the January 1991 outburst SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE stars, individual : Cygnus X-3; X-ray binaries; interferometry : VLBI; quasars; galaxies : jets; interstellar matter ID SEPTEMBER RADIO OUTBURST; EXPANSION; EMISSION; 0.35C; GHZ AB We report on high sensitivity VLBI observations of Cygnus X-3 at 6 cm wavelength on four consecutive days during the large radio flaring event in January, 1991. Both total flux density evolution and visibility amplitudes indicate the presence of a complex jet. The superposition of flares however excludes unique modelling of the source structure and evolution. The minimum consistent interpretation requires at least five components of scattering size 16 milliarc-seconds (mas), resulting in a linear structure with a position angle of 180 degrees with an uncertainty estimate of +/- 1O degrees. C1 German Aerosp Res Estab DLR Adlershof, Inst Space Sensor Technol, D-12489 Berlin, Germany. Max Planck Inst Radioastron, D-53121 Bonn, Germany. USN Observ, Washington, DC 20392 USA. USN, Res Lab, Remote Sensing Div, Washington, DC 20375 USA. CNR Bologna, Ist Radioastron, VLBI Stn, Noto, Italy. Univ Birmingham, Sch Phys & Space Res, Birmingham B15 2TT, W Midlands, England. Natl Radio Astron Observ, Green Bank, WV 24944 USA. CNR, Ist Radioastron, I-40129 Bologna, Italy. Radiosterrenwacht, NL-7990 AA Dwingeloo, Netherlands. Nuffield Radio Labs, Jodrell Bank, Macclesfield SK11 9DL, Cheshire, England. RP Schalinski, C (reprint author), Deutsch Forschungszentrum Luft & Raumfahrt eV DLR, Inst Weltraumsensorik, Rudower Chaussee 5, D-12489 Berlin, Germany. EM schalinski@dlr.de OI Venturi, Tiziana/0000-0002-8476-6307 NR 18 TC 11 Z9 11 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD JAN PY 1998 VL 329 IS 2 BP 504 EP 510 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA YQ939 UT WOS:000071439900013 ER PT J AU Harris, MJ Murphy, RJ Share, GH Johnson, WN Kinzer, RL Kurfess, JD McNaron-Brown, K Purcell, WR AF Harris, MJ Murphy, RJ Share, GH Johnson, WN Kinzer, RL Kurfess, JD McNaron-Brown, K Purcell, WR TI OSSE observations of the Orion giant molecular cloud during 1996 SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE ISM : individual objects : Orion clouds; cosmic rays; gamma-rays : observations ID GAMMA-RAY LINES; COMPLEX; SPECTROSCOPY; MONOCEROS AB We have combined all OSSE spectra of the Orion molecular cloud complex obtained through the end of 1996 and searched them for evidence of cosmic-ray induced gamma-ray lines in the 3-7 MeV energy range, as detected by COMPTEL (Bloemen et al. 1994, 1997). We do not detect any significant line emission; our flux estimate for broad-line emission of 1.5 +/- 1.0 10(-4) gamma/(cm(2)-s) is consistent with the spatially-extended flux 1.3 10(-4) gamma/(cm(2)-s) measured by Bloemen et al. (1997). C1 NASA, USRA, GVSP, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. USN, Res Lab, Washington, DC 20375 USA. George Mason Univ, Phys CSI, Fairfax, VA 22030 USA. Northwestern Univ, Dept Phys & Astron, Evanston, IL 60208 USA. RP Harris, MJ (reprint author), NASA, USRA, GVSP, Goddard Space Flight Ctr, Code 661, Greenbelt, MD 20771 USA. RI Johnson, Neil/G-3309-2014 NR 15 TC 5 Z9 5 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD JAN PY 1998 VL 329 IS 2 BP 624 EP 630 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA YQ939 UT WOS:000071439900026 ER PT J AU Hoflich, P Wheeler, JC Khokhlov, A AF Hoflich, P Wheeler, JC Khokhlov, A TI Hard x-rays and gamma rays from Type Ia supernovae SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays, theory; nuclear reactions, nucleosynthesis, abundances; supernovae, general; supernova remnants ID WHITE-DWARF MODELS; LIGHT CURVES; EVOLUTION; SPECTRA; 1991T; DETONATION; MECHANISMS; BINARIES; STARS; NOVAE AB The gamma-ray light curves and spectra are presented for a set of theoretical Type Ta supernova (SN Ia) models including deflagration, detonation, delayed detonation, and pulsating delayed detonations of Chandrasekhar-mass white dwarfs, as well as merger scenarios that may involve more than the Chandrasekhar mass and helium detonations Of sub-Chandrasekhar-mass white dwarfs. The results have been obtained with a Monte Carlo radiation transport scheme that takes into account all relevant gamma-transitions and interaction processes, The result is a set of accurate line profiles that are characteristic of the initial Ni-56 mass distribution of the supernova models. The gamma-rays probe the isotopic rather than merely the elemental distribution of the radioactive elements in the ejecta. Details of the line profiles (including the line width, shift with respect to the rest frame, and line ratios) are discussed. With sufficient energy and temporal resolution, different model scenarios can clearly be distinguished. Observational strategies are discussed for current and immediately upcoming generations of satellites (Compton Gamma Ray Observatory [CGRO] and International Gamma-Ray Astrophysical Laboratory [INTEGRAL]), as well as projected future missions including presently unavailable equipment such as Laue telescopes, With CGRO, it is currently possible with sufficiently early observations (near optical maximum) to distinguish helium detonations from explosions of Chandrasekhar-mass progenitors and of those involving mergers up to a distance of about 15 Mpc. This translates into one target of opportunity every 8 years. SNe Ia up to about 10 Mpc would allow detailed CGRO studies of line ratios of Co-56 lines. INTEGRAL will be able to perform detailed studies of the Co-56 line profiles with a range comparable to CGRO, The superior sensitivity of INTEGRAL for low energies makes detection and detailed study of the positron annihilation line and appropriate low-energy Ni-56 lines possible up to about 10-15 Mpc for all models. This capability means that this lower energy range may be the most useful for INTEGRAL detection and study of SNe Ia. Such studies will allow the determination of the precise time of the explosion. Whereas the current generation of gamma-ray detectors will allow the study of supernovae that are discovered by other means, a new generation of proposed gamma-ray detectors with sensitivity of about 10(-6) photons s(-1) cm(-2) would generate the opportunity to discover supernovae by their ii-ray emission up to a distance of approximate to 100 Mpc. This would allow a systematic study of the variety of SNe Ia in terms of their gamma-ray properties, independent of their optical properties. In addition, since gamma-rays are not obscured by the host galaxy, such experiments would, for the first time, provide absolute supernova rates. Relative rates as a function of the morphology of and position in the host galaxy could be studied directly. C1 Univ Texas, Dept Astron, Austin, TX 78710 USA. Univ Basel, Dept Phys, CH-7046 Basel, Switzerland. USN, Res Lab, Computat Phys & Fluid Dynam Lab, Washington, DC 20375 USA. RP Hoflich, P (reprint author), Univ Texas, Dept Astron, Austin, TX 78710 USA. NR 62 TC 27 Z9 27 U1 0 U2 0 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 JAN 1 PY 1998 VL 492 IS 1 BP 228 EP 245 DI 10.1086/305018 PN 1 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA YQ455 UT WOS:000071389300021 ER PT J AU Lean, JL Cook, J Marquette, W Johannesson, A AF Lean, JL Cook, J Marquette, W Johannesson, A TI Magnetic sources of the solar irradiance cycle SO ASTROPHYSICAL JOURNAL LA English DT Article DE Sun, activity; Sun, faculae, plages; Sun, fundamental parameters; Sun, magnetic fields ID TEMPERATURE-MINIMUM REGION; PHOTOMETRIC SUNSPOT INDEX; LUMINOSITY VARIATIONS; RADIATIVE OUTPUT; K-LINE; COMPARISON EXPERIMENT-1; ULTRAVIOLET IRRADIANCE; ACTIVE REGIONS; VARIABILITY; SUN AB Using recently processed Ca K filtergrams, recorded with a 1 Angstrom filter at the Big Bear Solar Observatory (BBSO), we quantitatively assess the component of solar irradiance variability attributable to bright magnetic features on the Sun's disk. The Ca K filtergrams, "flattened" by removing instrumental effects and center-to-limb variations, provide information about bright sources of irradiance variability associated with magnetic activity in both active regions and dispersed active region remnants broadly distributed in the supergranule network (termed collectively "faculae"). Procedures are developed to construct both total and UV spectral solar irradiance variations explicitly from the processed Ca K filtergrams, independently of direct irradiance observations. The disk-integrated bolometric and UV facular brightness signals determined from the filtergrams between late 1991 and mid-1995 are compared with concurrent solar irradiance measurements made by high-precision solar radiometers on the Upper Atmosphere Research Satellite (UARS). The comparisons suggest that active-region and active-network changes can account for the measured variations. This good agreement during a period covering most of the decline in solar activity from the cycle 22 maximum to the impending solar minimum directly implicates magnetic features as the sources of the 11 yr irradiance cycle, apparently obviating the need for an additional component other than spots or faculae. C1 USN, Res Lab, EO Hulburt Ctr Space Res, Washington, DC 20375 USA. CALTECH, Big Bear Solar Observ, Pasadena, CA 91125 USA. RP Lean, JL (reprint author), USN, Res Lab, EO Hulburt Ctr Space Res, Washington, DC 20375 USA. EM lean@demeter.nrl.navy.mil; cook@hrts.nrl.navy.mil; whm@suncub.bbso.caltech.edu; anders@suncub.bbso.caltech.edu OI Lean, Judith/0000-0002-0087-9639 NR 74 TC 86 Z9 87 U1 0 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 JAN 1 PY 1998 VL 492 IS 1 BP 390 EP 401 DI 10.1086/305015 PN 1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA YQ455 UT WOS:000071389300033 ER PT S AU Dere, K Mason, H AF Dere, K Mason, H BE Mohr, PJ Wiese, WL TI A new perspective on the Sun from SOHO - Challenges for atomic physics SO ATOMIC AND MOLECULAR DATA AND THEIR APPLICATIONS: ICAMDATA - FIRST INTERNATIONAL CONFERENCE SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 1st International Conference on Atomic and Molecular Data and Their Applications (ICAMDATA) CY SEP 29-OCT 02, 1997 CL NATL INST STAND & TECHNOL, GAITHERSBURG, MD SP Amer Inst Phys, US Dept Commerce, Technol Adm, Natl Inst Stand & Technol, Stand Reference Data Program, Natl Inst Stand & Technol, Atom Phys Div, Phys Lab, Elect Power Res Inst, US DOE, Off Fus Energy Sci, Harvard Smithsonian Ctr Astrophys, Inst Theoret Atom & Molec Phys, USN, Naval Res Lab, SEMATECH, NASA, Off Space Sci HO NATL INST STAND & TECHNOL AB The Solar and Heliospheric Observatory (SOHO) carries several ultraviolet spectrometers to diagnose the plasma conditions of the solar atmosphere in order to address several outstanding questions in solar research: why is the corona hot and how is the solar wind accelerated. Diagnostic techniques for determining the magnetohydrodynamic state (magnetic field, density, temperature, velocity) are discussed. We describe the CHIANTI database which has been designed to provide the necessary spectroscopic diagnostics for these data as well as for other spectroscopic missions. The database is built on 3 main files for each ion: atomic energy levels, radiative data, and electron collisional data. The electron collision strengths are assessed and scaled using the Burgess and Tully scaling laws. Analyses of EUV line intensities often reveal discrepancies between observed and predicted line intensities of about of 2 when considering lines of the same ion. A more recent analysis has shown that it is possible to arrive at a subset of EUV spectral lines where the line intensities are reproducible to within about 25%. For X-ray lines, as will be observed by AXAF, there is still considerable need for energy levels, radiative data and collision strengths, particularly for the Delta n greater than or equal to 1 transitions. C1 USN, Res Lab, Washington, DC 20375 USA. RP Dere, K (reprint author), USN, Res Lab, Washington, DC 20375 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-751-0 J9 AIP CONF PROC PY 1998 VL 434 BP 213 EP 220 PG 8 WC Physics, Applied; Physics, Atomic, Molecular & Chemical; Physics, Multidisciplinary SC Physics GA BL48Y UT WOS:000075685200015 ER PT J AU Bhatia, AK Doschek, CA AF Bhatia, AK Doschek, CA TI Atomic data and spectral line intensities for Ni XIII SO ATOMIC DATA AND NUCLEAR DATA TABLES LA English DT Article ID CROSS-SECTIONS; TRANSITIONS; EXCITATION; IX AB Electron impact collision strengths and spontaneous radiative decay rates are calculated for Ni XIII. The data pertain to the 48 levels of the configurations 3s(2)3p(4), 3s3p(5), 3s(2)3p(3)3d, and 3p(6). Collision strengths are calculated at five incident electron energies: 10.0, 20.0, 30.0, 40.0, and 50.0 Ry. Relative spectral line intensities are calculated for all astrophysically important transitions. These are obtained by computing the excitation rate coefficients (cm(3) s(-1)), i.e., the collision strengths integrated over a Maxwellian electron distribution, and then solving the equations of detailed balance for the populations of the 48 energy levels, assuming a collisional excitation model and an electron temperature of 2.0 x 10(6) K. This temperature is typical for Ni XIII when formed in equilibrium by collisional ionization and recombination. Using the excitation rate coefficients and the radiative decay rates, level populations are computed for several electron densities and are given in this paper. We also investigate the effects of proton excitation and solar radiative excitation on the level populations and line intensities. (C) 1998 Academic Press. C1 NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. USN, Res Lab, EO Hulburt Ctr Space Res, Washington, DC 20375 USA. RP Bhatia, AK (reprint author), NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. NR 20 TC 5 Z9 5 U1 0 U2 1 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0092-640X J9 ATOM DATA NUCL DATA JI Atom. Data Nucl. Data Tables PD JAN PY 1998 VL 68 IS 1 BP 49 EP 90 DI 10.1006/adnd.1997.0757 PG 42 WC Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Physics GA ZE154 UT WOS:000072763500002 ER PT S AU Davis, J Clark, RW Giuliani, JL Thornhill, JW AF Davis, J Clark, RW Giuliani, JL Thornhill, JW BE Oks, E Pindzola, MS TI Plasma spectroscopy of pulsed power driven Z-pinch plasmas SO ATOMIC PROCESSES IN PLASMAS: ELEVENTH APS TOPICAL CONFERENCE SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 11th APS Topical Conference on Atomic Processes in Plasmas CY MAR 23-26, 1998 CL AUBURN, AL AB Over the years there has been a sustained interest in and fascination with Z-pinch plasmas. Whether the interest is in radiation source development, fusion plasmas, and hohlraum physics or basic research there exits an extensive bibliography of literature presenting a variety of claims regarding the performance of Z-pinch plasmas. In this paper we will study the dynamics of Z-pinch plasma loads and focus primarily on the production of soft x-ray radiation. Many of the issues and revelations are common to Z-pinch plasmas in general but the attention here will be focused on the loads radiative performance. For the cases investigated here the load is heated by a multi-terawatt pulsed power accelerator. A radiation hydrodynamic model self-consistently driven by a circuit describes the dynamic evolution of the massive Al multiwire load. Predictions are made for the K- and L-shell soft x-ray emission as a function of the ionization dynamic model. The ionization dynamic models are represented by 1) a time-dependent NonEquilibrium (NEQ) model, 2) a Collisional Radiative Equilibrium (CRE) model and 3) a Local Thermodynamic Equilibrium (LTE) model. For all three scenarios the radiation is treated I) in the free streaming optically thin approximation where the plasma is treated as a volume emitter and 2) in the optically thick regime where the opacity for the lines and continuum is calculated online and transported through the plasma. Each simulation is carried out independently to determine the sensitivity of the implosion dynamics to the ionization and radiation model, i.e., how it affects the radiative yield and emission spectra. Results will be presented for the L- and K-shell radiation yields and emission spectra representing the radiation intensity as a function of photon energy from 10 eV to 10 keV. The predictions from the Various ionization models will be compared and contrasted with experimental results wherever possible. C1 USN, Res Lab, Div Plasma Phys, Radiat Hydrodynam Branch, Washington, DC 20375 USA. RP Davis, J (reprint author), USN, Res Lab, Div Plasma Phys, Radiat Hydrodynam Branch, Washington, DC 20375 USA. NR 0 TC 1 Z9 1 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-802-9 J9 AIP CONF PROC PY 1998 VL 443 BP 199 EP 215 DI 10.1063/1.56570 PG 17 WC Physics, Fluids & Plasmas; Physics, Atomic, Molecular & Chemical SC Physics GA BL94X UT WOS:000077262700016 ER PT S AU Giuliani, JL Apruzese, JP Dasgupta, A Kepple, P Rogerson, J Shamamian, V Counts, D Bicknell-Tassius, R Grunthaner, FJ AF Giuliani, JL Apruzese, JP Dasgupta, A Kepple, P Rogerson, J Shamamian, V Counts, D Bicknell-Tassius, R Grunthaner, FJ BE Oks, E Pindzola, MS TI Spectroscopic modeling and interpretation of industrial plasmas in materials processing SO ATOMIC PROCESSES IN PLASMAS: ELEVENTH APS TOPICAL CONFERENCE SE AIP CONFERENCE PROCEEDINGS LA English DT Meeting Abstract CT 11th APS Topical Conference on Atomic Processes in Plasmas CY MAR 23-26, 1998 CL AUBURN, AL C1 USN, Res Lab, Div Plasma Phys, Washington, DC 20375 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-802-9 J9 AIP CONF PROC PY 1998 VL 443 BP 366 EP 366 DI 10.1063/1.56577 PG 1 WC Physics, Fluids & Plasmas; Physics, Atomic, Molecular & Chemical SC Physics GA BL94X UT WOS:000077262700032 ER PT S AU Carosella, CA Hubler, GK Cotell, CM Schiestel, S AF Carosella, CA Hubler, GK Cotell, CM Schiestel, S BE Barbour, JC Roorda, S Ila, D Tsujioka, M TI Metastable materials formation by ion beam assisted deposition: Application to metal clusters in ceramic matrices SO ATOMISTIC MECHANISMS IN BEAM SYNTHESIS AND IRRADIATION OF MATERIALS SE Materials Research Society Symposium Proceedings LA English DT Proceedings Paper CT Symposium KK - on Atomistic Mechanisms in Beam Synthesis and Irradiation of Materials at the 1997 MRS Fall Meeting CY DEC 01-02, 1997 CL BOSTON, MA SP Mat Res Soc, Alabama A&M Univ, Ctr Irradiation Mat, High Volage Engn Europa B.v., Natl Electrostatics Corp, Sumitomo Elect Ind Ltd ID THIN-FILM DEPOSITION; OPTICAL-PROPERTIES; IMPLANTATION; ENERGY; SILICA AB The collision cascade, the fundamental event in ion-solid interactions, is responsible for the beneficial effects on thin films deposited by low energy ion beam assisted deposition (IBAD) or by energetic ion assisted deposition processes in general. However, the fundamental implications of the marriage of collision cascades and film growth processes have yet to be fully realized. The first half of this paper reviews the effects of ion bombardment on film growth and reaches some new conclusions. We propose that IBAD represents a different ion-solid interaction in a fundamental sense, and that as such, it should lead to new microstructures unattainable by other materials synthesis methods. The second part of this paper discusses the deposition of metal nanoclusters in a dielectric matrix by means of (b) under bar eam (a) under bar ssisted (p) under bar hase (s) under bar eparation (BAPS), a term coined here to describe deposition of phase-separated multicomponent materials. Examples discussed are gold nanoparticles in both niobium oxide and silica matrices. C1 USN, Res Lab, Surface Modificat Branch, Washington, DC 20375 USA. RP Carosella, CA (reprint author), USN, Res Lab, Surface Modificat Branch, Washington, DC 20375 USA. NR 26 TC 0 Z9 0 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-409-2 J9 MATER RES SOC SYMP P PY 1998 VL 504 BP 289 EP 299 PG 11 WC Materials Science, Ceramics; Materials Science, Characterization & Testing; Materials Science, Coatings & Films SC Materials Science GA BM67L UT WOS:000079427800044 ER PT S AU Schiestel, S Carosella, CA Stroud, R Guha, S Cotell, CM Grabowski, KS AF Schiestel, S Carosella, CA Stroud, R Guha, S Cotell, CM Grabowski, KS BE Barbour, JC Roorda, S Ila, D Tsujioka, M TI Ion beam effects on the formation of semiconductor nanoclusters SO ATOMISTIC MECHANISMS IN BEAM SYNTHESIS AND IRRADIATION OF MATERIALS SE Materials Research Society Symposium Proceedings LA English DT Proceedings Paper CT Symposium KK - on Atomistic Mechanisms in Beam Synthesis and Irradiation of Materials at the 1997 MRS Fall Meeting CY DEC 01-02, 1997 CL BOSTON, MA SP Mat Res Soc, Alabama A&M Univ, Ctr Irradiation Mat, High Volage Engn Europa B.v., Natl Electrostatics Corp, Sumitomo Elect Ind Ltd ID SI-RICH SIO2-FILMS; NANOCRYSTALS; DEPOSITION; FILMS AB Silicon rich silica films were deposited by coevaporation of silica and silicon with and without simultaneous ion bombardment. The Si-silica ratios are correlated to changes of index of refraction and shifts in an asymmetric stretching mode IR absorption. Photoluminescence between 550 and 600 nm is observed for all films which is attributed to SiO2 defects. After annealing this photoluminescence peak shows a shift to 750 nm and an increase in intensity, indicating the formation of silicon nanoclusters. This effect is more pronounced for samples prepared without ion beam treatment. ERD measurements show a correlation of photoluminescence with the presence of hydrogen in the films. The microstructure of these films were investigated by TEM. Photoluminescence from the Si nanoclusters in the films is optimized when the arrival rate of Si/silica is slightly less than 0.4. C1 USN, Res Lab, Washington, DC 20375 USA. RP Schiestel, S (reprint author), USN, Res Lab, 4555 Overlook Ave, Washington, DC 20375 USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-409-2 J9 MATER RES SOC SYMP P PY 1998 VL 504 BP 405 EP 410 PG 6 WC Materials Science, Ceramics; Materials Science, Characterization & Testing; Materials Science, Coatings & Films SC Materials Science GA BM67L UT WOS:000079427800061 ER PT S AU Wallet, BC Sadjadi, FA AF Wallet, BC Sadjadi, FA BE Sadjadi, FA TI A first look at a test statistic for dimensionality reduction SO AUTOMATIC TARGET RECOGNITION VIII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Automatic Target Recognition VIII CY APR 13-17, 1998 CL ORLANDO, FL SP SPIE AB Previous work by the authors has studied the problem of searching for projections to low dimensional spaces which are optimal for classification based upon some training data set. In our earlier work, we relied upon using seperate training and test data to attempt to estimate and correct the problem of overfitting. In this paper, we examine the problems introduced by using seperate training and test data. We then propose a new approach based upon searching projections based upon maximizing the Mann-Whitney test statistic. We discuss efforts made towards calculating the exact distribution of the supremum of this statistic over the Grassmannian manifold of projections to R-1. C1 USN, Ctr Surface Warfare, Dahlgren Div, Adv Computat Technol Grp, Dahlgren, VA 22448 USA. RP Wallet, BC (reprint author), USN, Ctr Surface Warfare, Dahlgren Div, Adv Computat Technol Grp, Dahlgren, VA 22448 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 0-8194-2820-5 J9 P SOC PHOTO-OPT INS PY 1998 VL 3371 BP 114 EP 118 DI 10.1117/12.323828 PG 5 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BL85K UT WOS:000076932900011 ER PT S AU Rogers, GW Mansfield, AW Poehler, PL Rais, H AF Rogers, GW Mansfield, AW Poehler, PL Rais, H BE Sadjadi, FA TI The wavenumber shift in Search and Rescue Synthetic Aperture Radar SO AUTOMATIC TARGET RECOGNITION VIII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Automatic Target Recognition VIII CY APR 13-17, 1998 CL ORLANDO, FL SP SPIE DE synthetic aperture radar; interferometry; IFSAR; Search and Rescue AB The wavenumber shift is an important tool in multiple pass synthetic aperture radar interferometry. In addition to overcoming baseline decorrelation, it has proven to have additional benefits. Chief among these is the ability to filter out much of the decorrelated signal, leaving the coherent portion. In the presence of foliage induced temporal decorrelation, this corresponds to filtering out much of the foliage return while strengthening any coherent ground return. We will examine this and other benefits of the wavenumber shift within the context of the Search and Rescue SAR program. An example based on ERS 1/2 data is provided. C1 USN, Ctr Surface Warfare, Dahlgren Div, Dahlgren, VA 22448 USA. RP Rogers, GW (reprint author), USN, Ctr Surface Warfare, Dahlgren Div, Code G50, Dahlgren, VA 22448 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 0-8194-2820-5 J9 P SOC PHOTO-OPT INS PY 1998 VL 3371 BP 209 EP 215 DI 10.1117/12.323839 PG 7 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BL85K UT WOS:000076932900021 ER PT S AU Mansfield, AW Rogers, GW Rais, H AF Mansfield, AW Rogers, GW Rais, H BE Sadjadi, FA TI Real-time SAR processing for Search and Rescue SO AUTOMATIC TARGET RECOGNITION VIII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Automatic Target Recognition VIII CY APR 13-17, 1998 CL ORLANDO, FL SP SPIE DE synthetic aperture radar; P-band; data compression; polarimetry; Search and Rescue AB The most important parameter in Search and Rescue is the time it takes to locate the downed aircraft and rescue the survivors. The resulting requirement for wide-area coverage, fine resolution, and day-night all-weather operation dictates the use of a SAR sensor. The time urgency dictates a real-time or near real-time SAR processor. This paper presents alternative real-time architectures and gives the results of feasibility studies of the enabling technologies, including new work by the authors in the area of SAR data compression. C1 USN, Ctr Surface Warfare, Washington, DC 20350 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 0-8194-2820-5 J9 P SOC PHOTO-OPT INS PY 1998 VL 3371 BP 233 EP 240 DI 10.1117/12.323843 PG 8 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BL85K UT WOS:000076932900024 ER PT S AU Kamgar-Parsi, B Zenner, TC Kamgar-Parsi, B Sciortino, JC Khan, A AF Kamgar-Parsi, B Zenner, TC Kamgar-Parsi, B Sciortino, JC Khan, A BE Sadjadi, FA TI Identification of distant insignia in a visual database SO AUTOMATIC TARGET RECOGNITION VIII SE Proceedings of SPIE LA English DT Proceedings Paper CT Conference on Automatic Target Recognition VIII CY APR 13-17, 1998 CL ORLANDO, FL SP SPIE DE automatic target recognition; color indexing; pattern recognition; visual database AB Searching a large visual database for the item(s) most similar to a test object is a tedious task that has many applications. This task is further complicated if the test object (extracted from an image) is degraded by its distance and other factors. A distant target is typically subject to blurring, noise, and other distortions, so that when it is matched to database items it: may turn out to be less similar to its own ideal model than another database item. To reduce the likelihood of such misidentifications, we propose an approach where the database is enlarged to include appropriately degraded versions of the ideal items in the original database. The extracted target is likely to match closely one of the distorted versions of its corresponding database item. In particular we discuss the problem of ship identification from the smokestack insignia, i.e.. extracting the ship's insignia from its color photo and finding its closest matches in a database containing thousands of registered shipping line insignias. This is a problem of interest to international regulatory agencies, insurance companies and others. We discuss how the database insignias, as well. as the extracted insignias, are processed and indexed, and how the distorted versions of ideal insignias are generated. C1 USN, Res Lab, Washington, DC 20375 USA. RP Kamgar-Parsi, B (reprint author), USN, Res Lab, Code 5585, Washington, DC 20375 USA. EM behzad@ait.nrl.navy.mil 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 0-8194-2820-5 J9 PROC SPIE PY 1998 VL 3371 BP 346 EP 353 PG 8 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BL85K UT WOS:000076932900035 ER PT S AU Poston, WL Marchette, D AF Poston, WL Marchette, D BE Sadjadi, FA TI High dimensional data computational demand minimization SO AUTOMATIC TARGET RECOGNITION VIII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Automatic Target Recognition VIII CY APR 13-17, 1998 CL ORLANDO, FL SP SPIE DE automatic pattern recognition; local dimensionality reduction; Fisher's linear discriminant; principal component analysis AB Dimensionality reduction is one way to reduce the computational load before analysis is attempted on massive high-dimensional data sets. It would be beneficial to have dimensionality reduction methods where the transformation can be updated recursively based on either known or partially identified data. This paper documents some of our recent work in dimensionality reduction that has applications to real-time automatic pattern recognition systems. Fisher's Linear Discriminant (FLD) is one method of reducing the dimensionality in pattern recognition applications where the covariances of each target group are the same. We develop two recursive versions of the FLD that are appropriate for the two-class case. The first is based on the assumption that it is known which class each new data point belongs to. This could be used with massive data sets where each observation is labeled with the true class and must be processed as it is obtained to build the classifiers. The other version recursively updates the FLD based on partially classified data. The FLD and other reduction methods such as principal component analysis offer global dimensionality reduction within the framework of linear algebra applied to covariance matrices. In this presentation, we describe local methods that use both mixture models and nearest neighbor calculations to construct local versions of these methods. These new versions for local dimensionality reduction provide increased classification accuracy in lower dimensions. C1 USN, Ctr Surface Warfare, Dahlgren, VA 22448 USA. RP Poston, WL (reprint author), USN, Ctr Surface Warfare, G33,17320 Dahlgren Rd, Dahlgren, VA 22448 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 0-8194-2820-5 J9 P SOC PHOTO-OPT INS PY 1998 VL 3371 BP 471 EP 479 DI 10.1117/12.323864 PG 9 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BL85K UT WOS:000076932900047 ER PT J AU Little, B Wagner, P Hart, K Ray, R Lavoie, D Nealson, K Aguilar, C AF Little, B Wagner, P Hart, K Ray, R Lavoie, D Nealson, K Aguilar, C TI The role of biomineralization in microbiologically influenced corrosion SO BIODEGRADATION LA English DT Article DE biomineralization; ferrihydrite; goethite; hematite; metal-reducing bacteria; microbiologically influenced corrosion; Shewanella putrefaciens ID PSEUDOMONAS SP; IRON; DISSOLUTION; REDUCTION; MANGANESE; GROWTH; OIL AB Synthetic iron oxides (goethite, alpha-FeO . OH; hematite, Fe2O3; and ferrihydrite, Fe(OH)(3)) were used as model compounds to simulate the mineralogy of surface films on carbon steel. Dissolution of these oxides exposed to pure cultures of the metal-reducing bacterium, Shewanella putrefaciens, was followed by direct atomic absorption spectroscopy measurement of ferrous iron coupled with microscopic analyses using confocal laser scanning and environmental scanning electron microscopies. During an 8-day exposure the organism colonized mineral surfaces and reduced solid ferric oxides to soluble ferrous ions. Elemental composition, as monitored by energy dispersive x-ray spectroscopy, indicated mineral replacement reactions with both ferrihydrite and goethite as iron reduction occurred. When carbon steel electrodes were exposed to S. putrefaciens, microbiologically influenced corrosion was demonstrated electrochemically and microscopically. C1 USN, Res Lab, Stennis Space Ctr, MS 39529 USA. Univ Wisconsin, Ctr Great Lakes Studies, Milwaukee, WI 53204 USA. RP Little, B (reprint author), USN, Res Lab, Code 7333, Stennis Space Ctr, MS 39529 USA. NR 21 TC 23 Z9 24 U1 2 U2 14 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0923-9820 J9 BIODEGRADATION JI Biodegradation PY 1998 VL 9 IS 1 BP 1 EP 10 DI 10.1023/A:1008264313065 PG 10 WC Biotechnology & Applied Microbiology SC Biotechnology & Applied Microbiology GA 129BP UT WOS:000076443600001 PM 9807800 ER PT B AU Hashimoto, RY Menon, ESK Saunders, M Fox, AG AF Hashimoto, RY Menon, ESK Saunders, M Fox, AG BE Pond, RC Clark, WAT King, AH Williams, DB TI Analytical electron microscopy studies of Cu-Al2O3 interfaces SO BOUNDARIES & INTERFACES IN MATERIALS: THE DAVID A. SMITH SYMPOSIUM LA English DT Proceedings Paper CT David A Smith Memorial Symposium on Boundaries and Interfaces in Materials at the 1997 TMS Fall Meeting CY SEP 15-18, 1997 CL INDIANAPOLIS, IN SP Minerals Met & Mat Soc, Electr Magnet & Photon Mat Div, Oxford Univ, IBM, Stevens Inst Technol, Lehigh Univ AB Analytical Electron Microscopy has been used to study a diffusion-bonded copper-alumina interface. The mechanical properties of this system are thought to depend on the interface chemistry which itself is controlled by the materials processing. We have used a combination of TEM imaging, EDX and EELS spectroscopies to study the microstructure and chemistry of the interface region. Of particular interest is the role (if any) of silicon which is the major impurity in the commercially available polycrystalline alumina which we have used as our substrate. Silicon is known to segregate to grain boundaries and triple junctions in polycrystalline alumina during sintering. The subsequent flow of silicon along the grain boundaries may provide a mechanism for the transport of silicon to the metal-ceramic interface. High silicon concentrations have been found at the triple junctions in the alumina. A combination of selected area diffraction, EDX and EELS suggests that the silicon exists as a mixture of glassy silica and fine mullite crystals. In addition, EDX analysis confirms that the silicon wets the grain boundaries in the vicinity of the triple junctions. No distinct silicon-bearing phase could be observed at the interface (either by bright-field imaging or elemental mapping using a Gatan Imaging Filter). EDX, however, confirmed the presence of silicon in varying concentrations up to similar to 10at%. The detection of significant silicon concentrations across large areas of the metal-ceramic interface suggests that the silicon can diffuse along the interface and does not simply arise from the intersection of alumina grain boundaries and triple junctions during the formation of the interface. Applying the spatial difference EELS technique to spectra acquired from the metal-ceramic interface produced two alternative scenarios. First, in regions shown to have low silicon concentrations the interface EELS is typical of results previously reported as exhibiting metal-to-metal coordinations. Second, in high silicon regions the interface EELS spectrum is similar to that attributed to mullite. C1 USN, Ctr Mat Sci & Engn, Dept Mech Engn, Postgrad Sch, Monterey, CA 93943 USA. RP Hashimoto, RY (reprint author), USN, Ctr Mat Sci & Engn, Dept Mech Engn, Postgrad Sch, Monterey, CA 93943 USA. RI Saunders, Martin/B-3082-2011 OI Saunders, Martin/0000-0001-6873-7816 NR 0 TC 0 Z9 0 U1 0 U2 0 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 0-87339-404-6 PY 1998 BP 161 EP 166 PG 6 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA BK53K UT WOS:000072465300019 ER PT S AU DeGiorgi, VG AF DeGiorgi, VG BE Kassab, A Chopra, M Brebbia, CA TI Finite resistivity and shipboard corrosion prevention system performance SO BOUNDARY ELEMENTS XX SE ADVANCES IN BOUNDARY ELEMENTS SERIES LA English DT Proceedings Paper CT 20th International Conference on the Boundary Element Method CY AUG, 1998 CL ORLANDO, FL SP Int Soc Boundary Elements, Amer Soc Mechan Engineers, FL Sect AB In the computational evaluation of electrochemical corrosion systems painted surfaces are often treated as perfectly insulated. While many paint systems have a high resistance; the resistance is finite rather than infinite. In this work a range of finite resistivity values will be assigned to the painted surfaces in a boundary element model of a shipboard ICCP system. The studies performed were developed to provide an increased understanding of the effects of finite resistivity on system performance, provide a quantitative measure of the effects of ranges of finite paint resistivity on system performance and to increase the understanding of modeling methods to issues of damage and material polarization response definitions. C1 USN, Res Lab, Mech Mat Branch, Washington, DC 20375 USA. RP DeGiorgi, VG (reprint author), USN, Res Lab, Mech Mat Branch, Code 6382, Washington, DC 20375 USA. NR 11 TC 0 Z9 0 U1 0 U2 0 PU COMPUTATIONAL MECHANICS PUBLICATIONS LTD PI SOUTHAMPTON PA ASHURST LODGE, SOUTHAMPTON S04 2AA, HANTS, ENGLAND SN 1460-1419 BN 1-85312-592-X J9 ADV BOUND ELEM SER PY 1998 VL 4 BP 555 EP 563 PG 9 WC Acoustics; Thermodynamics; Engineering, Chemical; Engineering, Mechanical; Mathematics, Applied; Mathematics; Mechanics SC Acoustics; Thermodynamics; Engineering; Mathematics; Mechanics GA BM70C UT WOS:000079532200052 ER PT B AU Locke, JB AF Locke, JB BE Magoon, OT Converse, H Baird, B MillerHenson, M TI Navy oil spill contingency planning SO CALIFORNIA AND THE WORLD OCEAN '97 - TAKING A LOOK AT CALIFORNIA'S OCEAN RESOURCES: AN AGENDA FOR THE FUTURE, VOLS 1 AND 2, CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT California and the World Ocean 97 Conference on Taking a Look at Californias Ocean Resources - An Agenda for the Future CY MAR 24-27, 1997 CL SAN DIEGO, CA C1 USN, Commander Base San Diego, San Diego, CA 92132 USA. RP Locke, JB (reprint author), USN, Commander Base San Diego, 937 N Harbor Dr, San Diego, CA 92132 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC CIVIL ENGINEERS PI NEW YORK PA UNITED ENGINEERING CENTER, 345 E 47TH ST, NEW YORK, NY 10017-2398 USA BN 0-7844-0297-3 PY 1998 BP 985 EP 990 PG 4 WC Engineering, Marine; Environmental Sciences; Oceanography; Remote Sensing; Water Resources SC Engineering; Environmental Sciences & Ecology; Oceanography; Remote Sensing; Water Resources GA BL35F UT WOS:000075224700126 ER PT J AU Chute, JP Frame, JN Hill, JM Davis, TA AF Chute, JP Frame, JN Hill, JM Davis, TA TI Acute cholecystitis and translocations t(14;18) and t(8;22): Rare presenting features in acute lymphoblastic leukemia which confer a poor prognosis SO CANCER RESEARCH THERAPY & CONTROL LA English DT Article DE acute lymphoblastic leukemia; cholecystitis; translocation ID B-CELL LEUKEMIA; FOLLICULAR LYMPHOMA; MALIGNANCIES; ACTIVATION; BIOLOGY; BCL-2; GENE AB Extramedullary presentations of acute lymphoblastic leukemia (ALL) are rare in the absence of demonstrable disease in the peripheral blood. In addition, the translocation of t(14;18)(q32;21) which is commonly observed in follicular Non-Hodgkin's lymphoma, is not typically associated with ALL. We have observed the t(14;18)(q32:q21) and t(8;22)(q24;q11) translocations in a patient with ALL who presented with gall bladder involvement as the sole initial manifestation of her disease. The ALL cells were Tdt negative and lacked surface immunoglobulin expression, which is unusual for adult ALL cells. The patient had a poor response to standard chemotherapy. The extramedullary presentation and the unusual chromosomal translocations each portend poor prognosis in a patient with ALL. Patients who have ALL with the t(14;ls)(q32;q21) and t(8;22)(q24;q11) translocations may have a unique variant of this disease and should be considered for more aggressive initial therapy or enrollment in an appropriate clinical trial. C1 USN, Med Res Inst, Immune Cell Biol Program, Bethesda, MD 20814 USA. Natl Naval Med Ctr, Div Hematol Oncol, Bethesda, MD USA. Uniformed Serv Univ Hlth Sci, Dept Med, Bethesda, MD 20814 USA. RP Chute, JP (reprint author), USN, Med Res Inst, Immune Cell Biol Program, Bethesda, MD 20814 USA. NR 24 TC 0 Z9 0 U1 0 U2 0 PU HARWOOD ACAD PUBL GMBH PI READING PA C/O STBS LTD, PO BOX 90, READING, BERKS, ENGLAND RG1 8JL SN 1064-0525 J9 CANCER RES THER CONT JI Cancer Res. Ther. Control PY 1998 VL 5 IS 4 BP 323 EP 328 PG 6 WC Oncology SC Oncology GA 135MJ UT WOS:000076805500018 ER PT J AU Sinnott, SB Shenderova, OA White, CT Brenner, DW AF Sinnott, SB Shenderova, OA White, CT Brenner, DW TI Mechanical properties of nanotubule fibers and composites determined from theoretical calculations and simulations SO CARBON LA English DT Article DE nanotubes; carbon composites; diamond; molecular simulation; mechanical properties ID MOLECULAR-DYNAMICS SIMULATIONS; NANOSCALE GRAPHITIC TUBULES; CARBON NANOTUBES; ATOMISTIC SIMULATIONS; FULLERENE TUBULES; DIAMOND FILMS; SURFACES; MICROTUBULES; DEPOSITION; ADHESION AB Theoretical Young's moduli have been estimated for carbon fibers composed of single-walled fullerene nanotubules aligned in the direction of the tubule axis. In the limit of infinitely long tubules, the fibers can have a Young's modulus comparable to that of diamond. Exploiting this property of nanotubule fibers, we investigate a new carbon composite composed of layered nanotubule fibers and diamond. Such a composite is found to be a high-modulus, low-density material that is quite stable to shear and other distortions. (C) 1997 Elsevier Science Ltd. C1 Univ Kentucky, Dept Chem & Mat Engn, Lexington, KY 40506 USA. N Carolina State Univ, Dept Mat Sci & Engn, Raleigh, NC 27695 USA. USN, Res Lab, Washington, DC 20375 USA. RP Sinnott, SB (reprint author), Univ Kentucky, Dept Chem & Mat Engn, Lexington, KY 40506 USA. RI Brenner, Donald/D-1741-2009; Sinnott, Susan/P-8523-2014 OI Sinnott, Susan/0000-0002-3598-0403 NR 44 TC 140 Z9 146 U1 0 U2 32 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0008-6223 J9 CARBON JI Carbon PY 1998 VL 36 IS 1-2 BP 1 EP 9 DI 10.1016/S0008-6223(97)00144-9 PG 9 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA YR759 UT WOS:000071527400002 ER PT J AU Wiercigroch, M Cheng, AHD Simmen, J Badiey, M AF Wiercigroch, M Cheng, AHD Simmen, J Badiey, M TI Nonlinear behavior of acoustic rays in underwater sound channels SO CHAOS SOLITONS & FRACTALS LA English DT Article; Proceedings Paper CT International Conference on Applied Chaotic Systems CY JUN, 1996 CL INOWLODZ, POLAND ID CHAOS; OCEAN AB The nonlinear behavior of acoustic rays in underwater sound channels is examined using a set of parabolic ray equations. Two sound speed profiles, a Munk canonical and a double-duct profile, are investigated. For range-independent but stratified ocean sound speed profiles, analytical results concerning the sound ray trajectory and wave length are obtained. The stability of the system is found to be marginal stable, which leads to the phenomenon of wave front folding. Next, a perturbed system attributed to a single-mode internal wave is examined. The stability, bifurcation and other nonlinear dynamic issues of the nearly integrable system are explored using a combination of phase plane trajectories, Poincare maps, bifurcation diagrams, Lyapunov exponents and Floquet multipliers. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 Univ Aberdeen, Kings Coll, Dept Engn, Aberdeen AB9 2UE, Scotland. Univ Delaware, Dept Civil & Environm Engn, Newark, DE 19716 USA. Off Naval Res, Ocean Acoust Program, Arlington, VA 22217 USA. Univ Delaware, Coll Marine Studies, Ocean Acoust Lab, Newark, DE 19716 USA. RP Wiercigroch, M (reprint author), Univ Aberdeen, Kings Coll, Dept Engn, Aberdeen AB9 2UE, Scotland. RI Wiercigroch, Marian/A-1021-2008; Cheng, Alexander/A-2765-2008; Badiey, Mohsen/H-3943-2012 OI Cheng, Alexander/0000-0001-5137-000X; NR 19 TC 7 Z9 7 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0960-0779 J9 CHAOS SOLITON FRACT JI Chaos Solitons Fractals PD JAN-FEB PY 1998 VL 9 IS 1-2 BP 193 EP 207 DI 10.1016/S0960-0779(97)00060-X PG 15 WC Mathematics, Interdisciplinary Applications; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA ZA072 UT WOS:000072326100020 ER PT J AU O'Brien, TD AF O'Brien, TD TI Fire and blood: 'Queynte' imaginings in Diana's temple SO CHAUCER REVIEW LA English DT Article C1 USN Acad, Annapolis, MD 21402 USA. RP O'Brien, TD (reprint author), USN Acad, Annapolis, MD 21402 USA. NR 27 TC 2 Z9 2 U1 0 U2 0 PU PENN STATE UNIV PRESS PI UNIVERSITY PK PA SUITE C, BARBARA BLDG. 820 NORTH UNIVERSITY DRIVE, UNIVERSITY PK, PA 16802-1003 USA SN 0009-2002 J9 CHAUCER REV JI Chaucer Rev. PY 1998 VL 33 IS 2 BP 157 EP 167 PG 11 WC Literature, British Isles; Medieval & Renaissance Studies SC Literature; Arts & Humanities - Other Topics GA 119KR UT WOS:000075895600004 ER PT J AU Coffey, CS AF Coffey, CS TI Initiation by impact or mild shock SO CHEMICAL PHYSICS REPORTS LA English DT Article; Proceedings Paper CT International Conference on Shock Waves in Condensed Media CY SEP 02-06, 1996 CL ST PETERSBURG, RUSSIA AB This paper concerns the initiation of chemical reactions in explosive crystals subjected to impact or mild shock. The energy dissipated within the crystals as they undergo plastic deformation due to the impact or shock provides the energy necessary to initiate chemical reaction. A general description of initiation due to impact or mild shock is dertermined and compared with a large body of experimental data. The ability of these mild stimuli to rank or predict the initiation sensitivity to strong shock is examined. C1 USN, Ctr Surface Warfare, White Oak Lab, Indian Head Div, Silver Spring, MD 20903 USA. RP Coffey, CS (reprint author), USN, Ctr Surface Warfare, White Oak Lab, Indian Head Div, Silver Spring, MD 20903 USA. NR 18 TC 0 Z9 0 U1 0 U2 2 PU GORDON BREACH SCI PUBL LTD PI READING PA C/O STBS LTD, PO BOX 90, READING RG1 8JL, BERKS, ENGLAND SN 1074-1550 J9 CHEM PHYS REP+ JI Chem. Phys. Rep. PY 1998 VL 17 IS 1-2 BP 3 EP 11 PG 9 WC Physics, Atomic, Molecular & Chemical SC Physics GA 263BB UT WOS:000084101800002 ER PT J AU Mintmire, JW Barrett, JJC Robertson, DH White, CT AF Mintmire, JW Barrett, JJC Robertson, DH White, CT TI Atomistic simulations of shock induced pore collapse in model materials SO CHEMICAL PHYSICS REPORTS LA English DT Article; Proceedings Paper CT International Conference on Shock Waves in Condensed Media CY SEP 02-06, 1996 CL ST PETERSBURG, RUSSIA ID HOT-SPOT FORMATION; MOLECULAR-DYNAMICS; WAVES; DETONATION; INITIATION AB We report on our ongoing molecular dynamics simulations of the interplay between shock waves and nanometer scale voids in solids. These studies involve simulations employing both nonreactive and reactive model potentials. We first describe our nonreactive three-dimensional model system of identical diatomic particles, internally coupled via harmonic potentials and ail interactions between diatoms modeled with Morse potentials. This is the simplest model where defect mediated coupling of the shock front to internal molecular degrees of freedom can be studied. Our simulations suggest that a shock front can induce localized vibrational heating in the vicinity of a void defect on picosecond time scales, even though these times are too short to reach thermal equilibrium between the vibrational energy and the overall kinetic energy. This region of vibrational excitation is observed to remain localized for several picoseconds while the overall thermal heating caused by the void defect dissipates into the surrounding environment. C1 USN, Res Lab, Washington, DC 20375 USA. Indiana Univ Purdue Univ, Dept Chem, Indianapolis, IN 46202 USA. RP Mintmire, JW (reprint author), USN, Res Lab, Washington, DC 20375 USA. OI Mintmire, John/0000-0002-6551-0349 NR 27 TC 2 Z9 2 U1 0 U2 0 PU GORDON BREACH PUBLISHING, TAYLOR & FRANCIS GROUP PI PHILADELPHIA PA 325 CHESTNUT ST, 8TH FL, PHILADELPHIA, PA 19106 USA SN 1074-1550 J9 CHEM PHYS REP+ JI Chem. Phys. Rep. PY 1998 VL 17 IS 1-2 BP 37 EP 46 PG 10 WC Physics, Atomic, Molecular & Chemical SC Physics GA 263BB UT WOS:000084101800005 ER PT J AU Elert, ML Barren, JJC White, CT AF Elert, ML Barren, JJC White, CT TI Investigation of detonation properties by molecular dynamics simulations SO CHEMICAL PHYSICS REPORTS LA English DT Article; Proceedings Paper CT International Conference on Shock Waves in Condensed Media CY SEP 02-06, 1996 CL ST PETERSBURG, RUSSIA AB During the past few years, molecular dynamics simulations have been shown to provide a unique method for studying the behavior of condensed matter at the atomic scale in the presence of shock waves. In particular, a model diatomic system employing a Reactive Empirical Bond Order (REBO) potential energy function has been developed [1,2] which produces reasonable values for shock wave velocity, peak temperature and density, and other properties of a chemically sustained shock wave. This model system provides an excellent mechanism for exploring the effect of specific changes in the properties of an energetic material undergoing shock-induced initiation. In particular, the potential energy function can be modified to systematically vary the amount of energy released in the model. We present the results of a study of the effect of changing exothermicity on this diatomic model system. The minimum energy release necessary to support a chemically sustained shock wave is reported, as well as the dependence of front velocity, reaction zone temperature, and density on the magnitude of energy release. C1 USN Acad, Annapolis, MD 21402 USA. USN, Res Lab, Washington, DC 20375 USA. RP Elert, ML (reprint author), USN Acad, Annapolis, MD 21402 USA. NR 5 TC 0 Z9 0 U1 0 U2 1 PU GORDON BREACH PUBLISHING, TAYLOR & FRANCIS GROUP PI PHILADELPHIA PA 325 CHESTNUT ST, 8TH FL, PHILADELPHIA, PA 19106 USA SN 1074-1550 J9 CHEM PHYS REP+ JI Chem. Phys. Rep. PY 1998 VL 17 IS 1-2 BP 185 EP 189 PG 5 WC Physics, Atomic, Molecular & Chemical SC Physics GA 263BB UT WOS:000084101800019 ER PT J AU Selinger, JV Selinger, RLB Jha, SK Green, MM AF Selinger, JV Selinger, RLB Jha, SK Green, MM TI A chiral polymeric analogy to a one-dimensional paramagnetic material SO CHIRALITY LA English DT Article DE polymers; polyisocyanates; helical conformation ID OPTICALLY-ACTIVE POLYISOCYANATES; MACROMOLECULAR STEREOCHEMISTRY; AMPLIFICATION; SENSE AB A class of polymers synthesized at DuPont in the late 1950's, the polyisocyanates, are the simplest analogs of the Nylons and have proven valuable as experimental models for theories of wormlike macromolecules. The macromolecular dimensional properties associated with all wormlike polymers arise from a strongly preferred local conformation of the chain and in the polyisocyanates this conformation is helical with an interesting additional property in that the mirror helical senses are of equal probability. Recent experiments have shown that discrimination between the helical senses can be accomplished with surprisingly small chiral influences indicating high cooperativity which arises from a conformational state in which long sections of one helical sense are separated from the other sense by infrequent helical reversals, This can be seen to be analogous to theoretical ideas about one-dimensional paramagnetic materials in which the spin states and the domain boundaries are analogs to the helical sense and the helical reversals in the polyisocyanates. The mathematical formalisms of the one-dimensional magnetic materials precisely describe the chiral properties of the polyisocyanates. (C) 1998 Wiley-Liss, Inc. C1 Polytech Univ, Herman F Mark Polymer Res Inst, Brooklyn, NY 11201 USA. USN, Res Lab, Ctr Biomol Sci & Engn, Washington, DC 20375 USA. Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. Polytech Univ, Dept Chem, Brooklyn, NY 11201 USA. RP Green, MM (reprint author), Polytech Univ, Herman F Mark Polymer Res Inst, 6 Metrotech Ctr, Brooklyn, NY 11201 USA. RI Selinger, Jonathan/D-1445-2010 OI Selinger, Jonathan/0000-0002-4982-2457 NR 22 TC 2 Z9 2 U1 0 U2 2 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC, 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0899-0042 J9 CHIRALITY JI Chirality PY 1998 VL 10 IS 1-2 BP 41 EP 45 PG 5 WC Chemistry, Medicinal; Chemistry, Analytical; Chemistry, Organic; Pharmacology & Pharmacy SC Pharmacology & Pharmacy; Chemistry GA YU906 UT WOS:000071768300008 ER PT S AU Siskind, DE Barth, CA Russell, JM AF Siskind, DE Barth, CA Russell, JM BE Rees, D TI A climatology of nitric oxide in the mesosphere and thermosphere SO CIRA PART III REFERENCE ATMOSPHERES - TRACE CONSTITUENT MODELS - COMPARISON WITH LATEST DATA SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT C4 3 Symposium of the COSPAR Scientific Commission C on CIRA Part III Reference Atmospheres : Trace Constituent Models - Comparison with Latest Data at the 31st COSPAR CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP Comm Space Res, Sci Comm Solar Terr Phys ID AURORAL STORM; LATITUDES; MIDDLE AB Global measurements of nitric oxide (NO) in the earth's upper atmosphere have now been obtained by two satellite experiments during the declining phases of the last two solar cycles. In the 1980's, NO was measured by the Solar Mesosphere Explorer while in the 1990's, NO has been observed by the Halogen Occultation Experiment (HALOE) on board the UARS satellite. The SME data cover the altitude range from 95 to 160 km and extend from pole to pole. The HALOE data used here cover the altitude range from 50 to 125 km and extend from 70N to 70S. Both datasets show a well defined decrease in NO during the decline of solar activity. Also, large perturbations due to auroral activity are seen at middle and high latitudes. In addition, the HALOE data show large increases in the high latitude winter mesosphere which are associated with downward transport from the thermosphere. This paper presents a reference NO model which is based upon the two datasets and which covers a wide range of solar, geomagnetic and seasonal conditions. Published by Elsevier Science Ltd on behalf of COSPAR. C1 USN, Res Lab, EO Hulburt Ctr Space Res, Washington, DC 20375 USA. Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80309 USA. NASA, Langley Res Ctr, Div Atmospher Sci, Hampton, VA 23681 USA. RP Siskind, DE (reprint author), USN, Res Lab, EO Hulburt Ctr Space Res, Washington, DC 20375 USA. NR 13 TC 37 Z9 37 U1 0 U2 2 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043463-0 J9 ADV SPACE RES PY 1998 VL 21 IS 10 BP 1353 EP 1362 DI 10.1016/S0273-1177(97)00743-6 PG 10 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BL14H UT WOS:000074437400001 ER PT J AU Sellami, L Newcomb, RW AF Sellami, L Newcomb, RW TI Computable real lattice structures for cochlea-like digital filters SO CIRCUITS SYSTEMS AND SIGNAL PROCESSING LA English DT Article AB A synthesis algorithm for a pipelined lattice implementation of cochlea-like digital filters is presented, based upon the properties of real, lossless lattice synthesis of ARMA fitters. The algorithm operates on a simplified characterization of elementary lattice sections of degree one or degree two. This leads to a structure that is recursively designed and for which each lattice is precisely implemented by a pair of complex conjugate transmission zeros via Richard's function extractions. Except for zeros of transmission on the unit circle, all other types and multiplicities are allowed. Necessary and sufficient conditions are derived for the degree-two lattices to guarantee computability, i.e., realizability with no delay-free loops. In addition to being suitable for VLSI realization, the structure enables a systematic cochlea assessment from the scattering ear parameters. C1 USN Acad, Dept Elect Engn, Annapolis, MD 21402 USA. Univ Maryland, Microsyst Lab, Dept Elect Engn, College Pk, MD 20742 USA. RP Sellami, L (reprint author), USN Acad, Dept Elect Engn, 105 Maryland Ave, Annapolis, MD 21402 USA. NR 22 TC 1 Z9 1 U1 0 U2 0 PU BIRKHAUSER BOSTON INC PI CAMBRIDGE PA 675 MASSACHUSETTS AVE, CAMBRIDGE, MA 02139 USA SN 0278-081X J9 CIRC SYST SIGNAL PR JI Circuits Syst. Signal Process. PY 1998 VL 17 IS 1 BP 103 EP 116 DI 10.1007/BF01213972 PG 14 WC Engineering, Electrical & Electronic SC Engineering GA YQ419 UT WOS:000071385100008 ER PT J AU Hutchins, RG Thaler, GJ AF Hutchins, RG Thaler, GJ TI An algebraic technique for designing active filters in the frequency domain for control and signal processing SO CIRCUITS SYSTEMS AND SIGNAL PROCESSING LA English DT Article AB This paper presents a straightforward algebraic method for designing feedback loops in the frequency domain. The emphasis here is on control system design, but the technique is applicable to active filter design as well. The object is to produce a practical analog filter with a minimum of design effort. The algebraic solution to the design problem is presented, and several examples are explored. C1 USN, Postgrad Sch, Monterey, CA 93943 USA. RP Hutchins, RG (reprint author), USN, Postgrad Sch, Monterey, CA 93943 USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU BIRKHAUSER BOSTON INC PI CAMBRIDGE PA 675 MASSACHUSETTS AVE, CAMBRIDGE, MA 02139 USA SN 0278-081X J9 CIRC SYST SIGNAL PR JI Circuits Syst. Signal Process. PY 1998 VL 17 IS 3 BP 391 EP 400 DI 10.1007/BF01202299 PG 10 WC Engineering, Electrical & Electronic SC Engineering GA ZU503 UT WOS:000074204600007 ER PT J AU Gray, GC McPhate, DC Leinonen, M Cassell, GH Deperalta, EP Putnam, SD Karcher, JA Sawyer, MH Laurila, A Connor, JD AF Gray, GC McPhate, DC Leinonen, M Cassell, GH Deperalta, EP Putnam, SD Karcher, JA Sawyer, MH Laurila, A Connor, JD TI Weekly oral azithromycin as prophylaxis for agents causing acute respiratory disease SO CLINICAL INFECTIOUS DISEASES LA English DT Article ID STREPTOCOCCUS-PYOGENES INFECTION; PENICILLIN-G BENZATHINE; CHLAMYDIA-PNEUMONIAE; RHEUMATIC-FEVER; UNITED-STATES; MARINE-CORPS; ETIOLOGICAL DIAGNOSIS; SEROLOGICAL METHODS; MILITARY RECRUITS; SERUM LEVELS AB Since the 1950s the U,S, military has used intramuscular injections of benzathine penicillin G (BPG) to control outbreaks of respiratory disease, In an effort to find an alternative prophylaxis, a randomized field trial was conducted among 1,016 male U,S, Marine trainee volunteers at high risk for respiratory disease, Participants were evaluated for evidence of acute respiratory infection by serological tests on pretraining and posttraining sera (63 days apart), Oral azithromycin prophylaxis (500 mg/w) outperformed BPG, preventing infection from Streptococcus pyogenes (Efficacy [E] = 84%; 95% confidence interval [CI], 63%-93%), Streptococcus pneumoniae (E = 80%; 95% CI, 50%-92%), Mycoplasma pneumoniae (E = 64%; 95% CI, 25%-83%), and Chlamydia pneumoniae (E = 58%; 95% CI, 15%-79%) in comparison with results in a no-treatment group, Azithromycin group subjects reported few side effects and less respiratory symptoms than the BPG and no-treatment groups, According to serological tests, oral azithromycin is an effective alternative prophylaxis to BPG for military populations. C1 USN, Hlth Res Ctr, Div Clin Epidemiol, Environm & Prevent Med Unit 5, San Diego, CA 92186 USA. Univ Calif San Diego, Dept Pediat, San Diego, CA 92103 USA. USN Hosp, Camp Pendleton, CA USA. Natl Publ Hlth Inst, Oulu, Finland. Univ Alabama, Dept Microbiol, Birmingham, AL 35294 USA. RP Gray, GC (reprint author), USN, Hlth Res Ctr, Div Clin Epidemiol, Environm & Prevent Med Unit 5, POB 85122, San Diego, CA 92186 USA. NR 50 TC 30 Z9 32 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 JAN PY 1998 VL 26 IS 1 BP 103 EP 110 DI 10.1086/516275 PG 8 WC Immunology; Infectious Diseases; Microbiology SC Immunology; Infectious Diseases; Microbiology GA YR235 UT WOS:000071474500017 PM 9455517 ER PT B AU Schultz, A Rekeczky, C Szatmari, I Roska, T Chua, LO AF Schultz, A Rekeczky, C Szatmari, I Roska, T Chua, LO BE Tavsanoglu, V TI Spatio-temporal CNN algorithm for object segmentation and object recognition SO CNNA 98 - 1998 FIFTH IEEE INTERNATIONAL WORKSHOP ON CELLULAR NEURAL NETWORKS AND THEIR APPLICATIONS - PROCEEDINGS LA English DT Proceedings Paper CT 5th IEEE International Workshop on Cellular Neural Networks and Their Applications CY APR 14-17, 1998 CL SO BANK UNIV LONDON, LONDON, ENGLAND SP Off Naval Res Europe, IEEE, IEE, European Circuit Soc HO SO BANK UNIV LONDON AB In this paper a spatio-temporal analogic CNN algorithm is designed for front-end filtering, segmentation and object recognition. First, a generalized segmentation strategy is presented based on various diffusion models. Both PDE and non-PDE related schemes are discussed and their VLSI complexity is analyzed. In classification (object recognition) a CNN implementation of the autowave metric, a "nonlinear" variant of the Hausdorff metric, is used, This approach turned out to be superior compared to some other classification methods, e.g. the Hamming distance calculation. A number of tests have been completed within the so-called "bubble/debris" segmentation experiments using original and artificial gray-scale images. C1 USN, Res Lab, Div Radar, Washington, DC 20375 USA. RP Schultz, A (reprint author), USN, Res Lab, Div Radar, 4555 Overlook Ave SW, Washington, DC 20375 USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4867-2 PY 1998 BP 347 EP 352 DI 10.1109/CNNA.1998.685400 PG 4 WC Computer Science, Artificial Intelligence; Computer Science, Interdisciplinary Applications; Computer Science, Theory & Methods; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BL34R UT WOS:000075211800063 ER PT J AU Chang, EJ Kailasanath, K AF Chang, EJ Kailasanath, K TI Dynamics and microexplosion of high energy fuels injected into a combustor SO COMBUSTION SCIENCE AND TECHNOLOGY LA English DT Article DE multiphase flow; combustor; combustion instability; high-energy fuels ID ACOUSTIC-VORTEX INTERACTIONS; CONFINED SHEAR-FLOW; NUMERICAL SIMULATIONS; DROPLET VAPORIZATION; MODELS; SPRAYS; JET AB The effects of microexploding fuel droplets injected into the shear layer in an axisymmetric dump combustor are studied numerically. The fuel droplets considered are multicomponent consisting of a solid high-energy fuel core surrounded by a liquid carrier. When droplets microexplode, pressure waves are generated that reverberate through the system and in some cases couple with the characteristic frequencies of the system. In a particular case, the low frequency quarter wave acoustic mode of the inlet is amplified, resulting in the formation of a large vortex structure near the combustor step. Periodic energy release associated with this large vortex structure sustains the low frequency oscillations even though droplets are injected continuously at a constant rate. By phase;coupling droplet injection to an external acoustic forcing frequency, it is demonstrated that pressure fluctuations at the forced frequency may be amplified or attenuated by the microexplosion of the fuel droplets. C1 USN, Res Lab, Computat Phys & Fluid Dynam Lab, Washington, DC 20375 USA. RP Kailasanath, K (reprint author), USN, Res Lab, Computat Phys & Fluid Dynam Lab, Washington, DC 20375 USA. EM kailas@lcp.nrl.navy.mil NR 41 TC 2 Z9 2 U1 0 U2 5 PU GORDON BREACH SCI PUBL LTD PI READING PA C/O STBS LTD, PO BOX 90, READING RG1 8JL, BERKS, ENGLAND SN 0010-2202 J9 COMBUST SCI TECHNOL JI Combust. Sci. Technol. PY 1998 VL 137 IS 1-6 BP 217 EP 236 DI 10.1080/00102209808952052 PG 20 WC Thermodynamics; Energy & Fuels; Engineering, Multidisciplinary; Engineering, Chemical SC Thermodynamics; Energy & Fuels; Engineering GA 148BJ UT WOS:000077532100010 ER PT J AU Prasad, K Li, C Kailasanath, K Ndubizu, C Ananth, R Tatem, PA AF Prasad, K Li, C Kailasanath, K Ndubizu, C Ananth, R Tatem, PA TI Numerical modeling of water mist suppression of methane-air diffusion flames SO COMBUSTION SCIENCE AND TECHNOLOGY LA English DT Article DE fire suppression; water mist; numerical modeling ID SECTIONAL APPROACH; FUEL SPRAYS; DROPLET; VAPORIZATION; COMBUSTION AB This paper describes a numerical model for studying the suppression of co-flow diffusion flames by fine water mist. A two-continuum formulation is used in which the gas phase and the water mist are both described by equations of the eulerian form. The model is used to obtain a detail understanding of the physical processes involved during the interaction of water mist and flames. The relative contribution of various mist suppression mechanisms is studied. The effect of droplet diameter, spray injection density and velocity on water mist entrainment into the dame and flame suppression is quantified. Droplet trajectories are used to identify the regions of the flame where the droplets evaporate and absorb energy. Finally, the model is used to determine the water required for extinction, and this is reported in terms of the ratio of the water supply rate to the fuel flow rate. C1 Sci Applicat Int Corp, Mclean, VA 22102 USA. USN, Res Lab, Computat Phys & Fluid Dynam Lab, Washington, DC 20375 USA. USN, Res Lab, Div Chem, Navy Technol Ctr Safety & Survivabil, Washington, DC 20375 USA. RP Prasad, K (reprint author), Sci Applicat Int Corp, Mclean, VA 22102 USA. NR 34 TC 33 Z9 33 U1 2 U2 14 PU GORDON BREACH SCI PUBL LTD PI READING PA C/O STBS LTD, PO BOX 90, READING RG1 8JL, BERKS, ENGLAND SN 0010-2202 J9 COMBUST SCI TECHNOL JI Combust. Sci. Technol. PY 1998 VL 132 IS 1-6 BP 325 EP + DI 10.1080/00102209808952019 PG 44 WC Thermodynamics; Energy & Fuels; Engineering, Multidisciplinary; Engineering, Chemical SC Thermodynamics; Energy & Fuels; Engineering GA 262XE UT WOS:000084092900012 ER PT J AU Kaplan, CR Patnaik, G Kailasanath, K AF Kaplan, CR Patnaik, G Kailasanath, K TI Universal relationships in sooting methane-air diffusion flames SO COMBUSTION SCIENCE AND TECHNOLOGY LA English DT Article DE sooting diffusion flames; direct numerical simulations ID LAMINAR FLAMELET; COMBUSTION; GROWTH; MODEL; DYNAMICS; RATES AB The laminar flamelet concept is based on the premise that scalar properties in laminar diffusion flames are nearly universal functions of mixture fraction. It has been well-tested and proven for temperature and the major species, however, few studies have addressed its applicability for minor species especially the radical species. In this study, we present a direct numerical simulation of an axisymmetric, laminar, methane-air diffusion flame to examine these universal relationships, including the major and minor chemical species, and the radical species. The numerical model solves the axisymmetric, time-dependent, reactive-flow Navier-Stokes equations coupled with sub-models for soot formation and radiation transport, and includes a detailed reaction mechanism for methane-air combustion. Quantitative comparisons with existing experimental data show a slightly wider computed flame compared to the experimental flame, however, the peak values and radial locations of temperature and soot volume fraction line up well with the experimental measurements. To study the universal relationships, scatter plots are made for temperature and the major and minor species throughout the entire flame and compared with existing experimental measurements. Excellent agreement is obtained between the computations and experiments for temperature and mole fractions of CH4, O-2, OH, H2O, O, H, CO2 and N-2, as a function of mixture fraction in the fuel lean, stoichiometric and fuel rich regions of the flame. The computations underpredicted the concentration of H-2 and CO in the fuel rich region, however, excellent agreement is obtained in the fuel lean and stoichiometric regions. The computations also overpredict the concentration of CH3 in the stoichiometric and fuel rich regions, however, the peak concentration occurs at the same mixture fraction for both the experiments and computations. The scatter plots indicate that many of the species studied, including the minor species and radical species, can be considered universal functions of mixture fraction, however some of the species show more scatter than others. The species which showed the least scatter were those whose production rates are fastest in the stoichiometric and fuel lean regions of the flame. Those species whose production rates were highest in the very fuel rich region showed less universality with mixture fraction. C1 USN, Res Lab, Computat Phys & Fluid Dynam Lab, Washington, DC 20375 USA. RP Kaplan, CR (reprint author), USN, Res Lab, Computat Phys & Fluid Dynam Lab, Code 6183, Washington, DC 20375 USA. NR 49 TC 9 Z9 9 U1 0 U2 4 PU GORDON BREACH SCI PUBL LTD PI READING PA C/O STBS LTD, PO BOX 90, READING RG1 8JL, BERKS, ENGLAND SN 0010-2202 J9 COMBUST SCI TECHNOL JI Combust. Sci. Technol. PY 1998 VL 131 IS 1-6 BP 39 EP 65 DI 10.1080/00102209808935754 PG 27 WC Thermodynamics; Energy & Fuels; Engineering, Multidisciplinary; Engineering, Chemical SC Thermodynamics; Energy & Fuels; Engineering GA ZT374 UT WOS:000074078700002 ER PT J AU Gaglione, AM Spellman, D AF Gaglione, AM Spellman, D TI Almost locally free groups and the genus question SO COMMUNICATIONS IN ALGEBRA LA English DT Article AB Sacerdote [Sa] has shown that the non-Abelian free groups satisfy precisely the same universal-existential sentences Th(F-2)boolean AND For All There Exists in a first-order language Lo appropriate for group theory. It is shown that in every model of Th(F-2)boolean AND For All There Exists the maximal Abelian subgroups are elementarily equivalent to locally cyclic groups (necessarily nontrivial and torsion free). Two classes of groups are interpolated between the non-Abelian locally free groups and Remeslennikov's There Exists-free groups. These classes are the almost locally free groups and the quasi-locally free groups. In particular, the almost locally free groups are the models of Th(F-2)boolean AND For All There Exists while the quasi-locally free groups are the There Exists-free groups with maximal Abelian subgroups elementarily equivalent to locally cyclic groups (necessarily nontrivial and torsion free). Two principal open questions at opposite ends of a spectrum are: (1.) Is every finitely generated almost locally free group free? (2.) Is every quasi-locally free group almost locally free? Examples abound of finitely generated quasi-locally free groups containing nontrivial torsion in their Abelianizations. The question of whether or not almost locally free groups have torsion free Abelianization is related to a bound in a free group on the number of factors needed to express certain elements of the derived group as a product of commutators. C1 USN Acad, Annapolis, MD 21402 USA. St Josephs Univ, Philadelphia, PA 19131 USA. RP Gaglione, AM (reprint author), USN Acad, Annapolis, MD 21402 USA. NR 23 TC 0 Z9 0 U1 0 U2 0 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 USA SN 0092-7872 J9 COMMUN ALGEBRA JI Commun. Algebr. PY 1998 VL 26 IS 9 BP 2821 EP 2836 DI 10.1080/00927879808826312 PG 16 WC Mathematics SC Mathematics GA 102KN UT WOS:000074923600007 ER PT J AU Yu, HY AF Yu, HY TI A new dislocation-like model for imperfect interfaces and their effect on load transfer SO COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING LA English DT Article; Proceedings Paper CT 5th International Conference on Interfacial Phenomena in Composite Materials CY SEP 01-03, 1997 CL EGER, HUNGARY DE interfacial properties; dislocation-like model; elastic field; Green's function; dislocations ID ELASTIC FIELDS; BIMATERIALS; COMPOSITES; INCLUSION; SOLIDS; LAYER AB A dislocation-like model is proposed to describe the boundary conditions of an imperfect interface. In this new model, a thin layer of interphase material is introduced near the interface. In the limit of vanishing layer thickness, the interfacial tractions become continuous, but the displacements on either side of the interphase layer become discontinuous. The jump in the displacement at the interface is described by Somigliana dislocations. The variable discontinuity of displacement across the interface is assumed to be Linearly proportional to the displacement at the interface of the constituent where the elastic singularity is. The result of applying this model is equivalent to introducing two effective interfacial moduli of rigidity. Using this model, the effect of imperfect interfaces on load transfer is studied. The Green's function is obtained for two semi-infinite solids with a planar interface. The elastic fields due to defects such as inclusions and dislocations are also given. (C) 1998 Published by Elsevier Science Ltd. All rights reserved. C1 USN, Res Lab, Washington, DC 20375 USA. RP Yu, HY (reprint author), USN, Res Lab, Washington, DC 20375 USA. NR 35 TC 24 Z9 25 U1 1 U2 7 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 1359-835X J9 COMPOS PART A-APPL S JI Compos. Pt. A-Appl. Sci. Manuf. PY 1998 VL 29 IS 9-10 BP 1057 EP 1062 DI 10.1016/S1359-835X(98)00010-4 PG 6 WC Engineering, Manufacturing; Materials Science, Composites SC Engineering; Materials Science GA 123AH UT WOS:000076103300008 ER PT J AU Kwon, YW Lee, JH Liu, CT AF Kwon, YW Lee, JH Liu, CT TI Study of damage and crack in particulate composites SO COMPOSITES PART B-ENGINEERING LA English DT Article DE particle-reinforcement; crack; damage; initiation; propagation ID BEHAVIOR AB Crack initiation and propagation was studied for particulate composite specimens with a notch. A numerical simulation was conducted to predict the crack behaviour based on the damage initiation, growth and local saturation; the results were compared to those obtained in the experimental study. In the numerical study, it was assumed that based on the observation of experimental results, a crack forms when a damage is saturated in a localized zone. Predicted crack sizes agreed well with the experimental results. The numerical simulation showed the crack propagation and temporary arrest as the notched specimen was continuously loaded. The experimental result also showed a temporary halt of crack propagation while the crack tip became blunt. Therefore, the prediction of crack initiation, growth and arrest was satisfactory using the concept of damage growth and saturation. In addition, the study indicated that an inhomogeneous material property, which usually results from a nonuniform particle distribution in a matrix material, significantly affected the crack behaviour in a particulate composite. (C) 1998 Elsevier Science Limited. All rights reserved. C1 USN, Postgrad Sch, Dept Mech Engn, Monterey, CA 93943 USA. Phillips Lab, Edwards AFB, CA 93524 USA. RP Kwon, YW (reprint author), USN, Postgrad Sch, Dept Mech Engn, Monterey, CA 93943 USA. NR 11 TC 9 Z9 11 U1 0 U2 1 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 1359-8368 J9 COMPOS PART B-ENG JI Compos. Pt. B-Eng. PY 1998 VL 29 IS 4 BP 443 EP 450 DI 10.1016/S1359-8368(98)80002-4 PG 8 WC Engineering, Multidisciplinary; Materials Science, Composites SC Engineering; Materials Science GA ZY882 UT WOS:000074671700010 ER PT J AU Palmer, DW Bank, LC Gentry, TR AF Palmer, DW Bank, LC Gentry, TR TI Progressive tearing failure of pultruded composite box beams: Experiment and simulation SO COMPOSITES SCIENCE AND TECHNOLOGY LA English DT Article ID TUBES AB The phenomenon of progressive tearing failure in thin-walled, rectangular-cross-section pultruded composite beams has been observed in beams loaded in flexure. In this failure mode, unique to composite materials, tearing refers to the separation of the vertical and horizontal members at the corners of the cross-section. In the experimental part of this investigation, pultruded composite box beams were loaded in three-point bending and subjected to a midspan deflection large enough to cause failure. This test measured the force vs displacement behavior of the beam. Tearing typically begins directly under the loading head and progresses toward the ends of the beam as vertical deflection increases. A methodology to simulate the three-point bending test numerically is being developed. The tearing action was modeled by using the LS-DYNA3D explicit finite-element software package. Comparison of numerically obtained force vs displacement results and experimental data showed that the finite-element model captures the overall behavior of the beam with sufficient accuracy to demonstrate its feasibility. (C) 1998 Elsevier Science Ltd. All rights reserved C1 Catholic Univ Amer, Dept Civil Engn, Washington, DC 20064 USA. Univ Wisconsin, Dept Civil & Environm Engn, Madison, WI 53706 USA. Georgia Inst Technol, Architecture Program, Atlanta, GA 30332 USA. RP Palmer, DW (reprint author), USN, Ctr Surface Warfare, Carderock Div, Code 6552,9500 MacArthur Blvd, Bethesda, MD 20817 USA. NR 11 TC 13 Z9 13 U1 0 U2 1 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0266-3538 J9 COMPOS SCI TECHNOL JI Compos. Sci. Technol. PY 1998 VL 58 IS 8 BP 1353 EP 1359 DI 10.1016/S0266-3538(98)00005-0 PG 7 WC Materials Science, Composites SC Materials Science GA 131PZ UT WOS:000076585600010 ER PT J AU Wu, EM Robinson, CS AF Wu, EM Robinson, CS TI Computational micro-mechanics for probabilistic failure of fiber composites in tension SO COMPOSITES SCIENCE AND TECHNOLOGY LA English DT Article DE computational composite reliability; micro-redundancy; strength size-effect; tri-modal fiber statistics; local load sharing ID FIBROUS MATERIALS; STRENGTH; DISTRIBUTIONS; BOUNDS; MODEL AB The design of a composite from fiber and matrix properties requires micro-mechanics modeling of strength. The strength of a composite has an inherent variability which is a manifestation of the underlying stochastic failure processes of the constituent fiber and matrix. For fiber-dominated tensile composite failures, the failure process starts with the breaking of weak fibers. The initial failure sites are isolated by micro-redundancy provided by local load-sharing of the neighboring fibers. Higher applied load leads to progressive clustering of fiber breaks which ultimately cause macroscopic failure. Probability modeling of the failure sequences of the fiber breaks and the spatial geometry of the clustering of the sites resulted in the local load-sharing model. This model requires numerical evaluation because it contains an extremely large matrix of the transitional probability of the occurrences of the cluster sites. This paper provides an accessible computational implementation of this model for computer platforms ranging from personal computers to supercomputers. The computational algorithm was made general by a three-section piecewise-linear, tri-modal model for fiber statistics. This tri-modal local load-sharing software numerically computes the cumulative distribution function (CDF) of the composite strength by using a very wide range of fiber statistics as input. This CDF can be used to analyze composite strength data in testing, to predict size effects in design, to monitor processing quality, and to quantify the reliability of composite structures. (C) 1998 Published by Elsevier Science Ltd. All rights reserved. C1 USN, Postgrad Sch, Monterey, CA 93853 USA. RP Wu, EM (reprint author), USN, Postgrad Sch, Monterey, CA 93853 USA. NR 11 TC 3 Z9 3 U1 1 U2 1 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0266-3538 J9 COMPOS SCI TECHNOL JI Compos. Sci. Technol. PY 1998 VL 58 IS 9 BP 1421 EP 1432 PG 12 WC Materials Science, Composites SC Materials Science GA 133VX UT WOS:000076708800006 ER PT J AU Dyka, CT Badaliance, R AF Dyka, CT Badaliance, R TI Damage in marine composites caused by shock loading SO COMPOSITES SCIENCE AND TECHNOLOGY LA English DT Article DE damage mechanics; composites; explicit analysis; finite difference; finite element; impact; shock; wave propagation ID MECHANICS; FRACTURE; SOLIDS AB This paper is a summary of our recent efforts here at NRL in developing a methodology for predicting the response of thick composite materials subjected to multidimensional shock loadings. A focus of this work has been the development of a 1D (one dimensional), 2D and 3D evolving damage model applicable to highly transient loading environments such as underwater shock and impact. This approach is phenomenological in nature and has achieved a degree of success. Comparisons with the results of impact experiments on 2D composite plates have been encouraging. In this work, the assumption is made of a local material damage and effective resisting area perspective, in which the evolving damage is considered to be a vector quantity. The ID concept also includes explicit dispersion/viscoelastic effects. Published by Elsevier Science Ltd. C1 Geocenters Inc, Ft Washington, MD 20744 USA. USN, Res Lab, Washington, DC 20375 USA. RP Dyka, CT (reprint author), Geocenters Inc, 10903 Indian Head Highway, Ft Washington, MD 20744 USA. NR 36 TC 6 Z9 6 U1 0 U2 1 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0266-3538 J9 COMPOS SCI TECHNOL JI Compos. Sci. Technol. PY 1998 VL 58 IS 9 BP 1433 EP 1442 PG 10 WC Materials Science, Composites SC Materials Science GA 133VX UT WOS:000076708800007 ER PT B AU Zolper, JC AF Zolper, JC BE Ren, F Abernathy, CR Buckley, DN Pearton, SJ Chu, SNG Parsey, JM Zolper, JC TI On the role of SiC and GaN in high power electronics SO COMPOUND SEMICONDUCTOR POWER TRANSISTORS AND STATE-OF-THE-ART PROGRAM ON COMPOUND SEMICONDUCTORS (SOTAPOCS XXIX) SE ELECTROCHEMICAL SOCIETY SERIES LA English DT Proceedings Paper CT Symposium on Compound Semiconductor Power Transistors / 29th State-of-the-Art Program on Compound Semiconductors at the 149th Meeting of the Electrochemical-Society CY NOV 01-06, 1998 CL BOSTON, MA SP Electrochem Soc, Electr Div AB Recent advances in the material quality of both SiC and GaN are enabling dramatic improvements in high power electronic devices. The impacted device technologies can be group into two class: 1) high power, low frequency power switching (e. g. MOSFETs, thyristors, IGBTs, MCT, etc.) and 2) high power microwave (e. g. FETs, HEMTs, HBTs, IMPATTs, etc.). Within these classes one can also differentiate between bipolar (thyristors, HBTs) and unipolar (FETs, MOSFETs) devices. This paper discusses the material, SiC or GaN, that will be most advantageous for each class of devices. C1 Off Naval Res, Div Elect, Arlington, VA 22217 USA. RP Zolper, JC (reprint author), Off Naval Res, Div Elect, Code 312,800 N Quincy St, Arlington, VA 22217 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU ELECTROCHEMICAL SOCIETY INC PI PENNINGTON PA 65 S MAIN ST, PENNINGTON, NJ 08534-2839 USA BN 1-56677-222-2 J9 ELEC SOC S PY 1998 VL 98 IS 12 BP 10 EP 15 PG 6 WC Electrochemistry; Engineering, Electrical & Electronic; Materials Science, Multidisciplinary SC Electrochemistry; Engineering; Materials Science GA BL94F UT WOS:000077242700002 ER PT S AU Kim, S Rhee, SJ Li, X Coleman, JJ Bishop, SG AF Kim, S Rhee, SJ Li, X Coleman, JJ Bishop, SG BE Melloch, M Reed, MA TI Trap-mediated, site-selective excitation of photoluminescence from multiple Er3+ sites in Er-implanted GaN SO COMPOUND SEMICONDUCTORS 1997 SE INSTITUTE OF PHYSICS CONFERENCE SERIES LA English DT Article; Proceedings Paper CT 24th IEEE International Symposium on Compound Semiconductors CY SEP 08-11, 1997 CL SAN DIEGO, CALIFORNIA SP IEEE, Motorola, USN, Off Naval Res, Siemens, Aixtron, EPI ID LUMINESCENCE AB Site-selective photoluminescence (PL) and photoluminescence excitation (PLE) spectroscopy have been carried out at 6 K on the similar to 1540 nm I-4(13/2) --> I-4(15/2) emissions of Er3+ in Er-implanted MOCVD GaN. The PLE spectroscopy has detected several independent, site-selective excitation mechanisms which demonstrate the existence of four different Er3+ sites in Er-implanted GaN. Each of these four Er3+ sites exhibits a distinctive PL spectrum characteristic of that center's environment when pumped by the appropriate wavelengths of below-gap light. Two of the site-selective Er3+ PL spectra pumped by trap-mediated excitation bands dominate the Er3+ PL spectrum excited by above-gap light. The PLE spectra demonstrate that the Er3+ PL spectra are excited by below gap absorption attributable to both implantation damage-induced defects and defects and impurities characteristic of the as-grown GaN. The temperature dependence of the Er3+ PL spectra was studied to examine thermal quenching properties of these site-specific Er3+ PL centers. C1 Univ Illinois, Microelect Lab, Urbana, IL 61801 USA. USN, Res Lab, Washington, DC 20375 USA. RP Kim, S (reprint author), Univ Illinois, Microelect Lab, Urbana, IL 61801 USA. RI Coleman, James/C-9703-2011; Li, Xiuling/A-2240-2010 NR 10 TC 0 Z9 0 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0951-3248 BN 0-7503-0556-8 J9 INST PHYS CONF SER PY 1998 VL 156 BP 203 EP 206 DI 10.1109/ISCS.1998.711616 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Multidisciplinary; Physics, Condensed Matter SC Engineering; Physics GA BL23S UT WOS:000074779700048 ER PT B AU Abrahams, J AF Abrahams, J BE Carpentieri, B DeSantis, A Vaccaro, U Storer, JA TI Code and parse trees for lossless source encoding SO COMPRESSION AND COMPLEXITY OF SEQUENCES 1997 - PROCEEDINGS LA English DT Proceedings Paper CT International Conference on Compression and Complexity of Sequences CY JUN 11-13, 1997 CL SALERNO, ITALY SP Univ Salerno, Dipartimento Informat & Applicaz RM Capocelli, CNR, IEEE Data Compress Conference C1 Off Naval Res, Math Comp & Informat Sci Div, Arlington, VA 22217 USA. RP Abrahams, J (reprint author), Off Naval Res, Math Comp & Informat Sci Div, Arlington, VA 22217 USA. NR 0 TC 5 Z9 5 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 0-8186-8132-2 PY 1998 BP 145 EP 171 DI 10.1109/SEQUEN.1997.666911 PG 27 WC Computer Science, Information Systems; Computer Science, Theory & Methods SC Computer Science GA BL01H UT WOS:000074045200014 ER PT S AU Heitmeyer, C Kirby, J Labaw, B Bharadwaj, R AF Heitmeyer, C Kirby, J Labaw, B Bharadwaj, R BE Hu, AJ Vardi, MY TI SCR: A toolset for specifying and analyzing software requirements SO COMPUTER AIDED VERIFICATION SE Lecture Notes in Computer Science LA English DT Article; Proceedings Paper CT 10th International Conference on Computer-Aided Verification (CAV 98) CY JUN 28-JUL 02, 1998 CL UNIV BRITISH COLUMBIA, VANCOUVER, CANADA SP Cadence Design Syst, Chrysalis Symbol Design, Dasssault Aviat, Fujitsu Ltd, Hewlett Packard, IBM Res, Intel, Lucent Technol, Mentor Graph, Motorola, NEC US, Prover Technol, Rockwell Collins, SGS Thomson Microelectr, Siemens, Sun Microsyst, Synopys, Verisity, Verysys HO UNIV BRITISH COLUMBIA AB A controversial issue in the formal methods community is the degree to which mathematical sophistication and theorem, proving skills should be needed to apply a formal method and its support tools. This paper describes the SCR (Software Cost Reduction) tools, part of a "practical" formal method-a method with a solid mathematical foundation that software developers can apply without theorem proving skills, knowledge of temporal and higher order logics, or consultation with formal methods experts. The SCR method provides a tabular notation for specifying requirements and a set of "light-weight" tools that detect several classes of errors automatically. The method also provides support for more "heavy-duty" tools, such as a model checker. To make model checking feasible, users can automatically apply one or more abstraction methods. C1 USN, Res Lab, Washington, DC 20375 USA. RP USN, Res Lab, Code 5546, Washington, DC 20375 USA. RI Heitmeyer, Constance/F-6500-2011; OI Heitmeyer, Constance/0000-0001-7942-9309 NR 15 TC 55 Z9 56 U1 0 U2 1 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 3-540-64608-6 J9 LECT NOTES COMPUT SC PY 1998 VL 1427 BP 526 EP 531 PG 6 WC Computer Science, Hardware & Architecture; Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA BN84L UT WOS:000083172700050 ER PT J AU Wu, C Dieguez, M AF Wu, C Dieguez, M TI Intelligent computer-aided design on optimization of specific power output of a finite-time Rankine cycle using CyclePad SO COMPUTER APPLICATIONS IN ENGINEERING EDUCATION LA English DT Article DE intelligent computer-aided design; optimization; Rankine cycle AB The specific output power of a shipboard nuclear propulsion system is analyzed. The plant consists of a Rankine cycle coupled to coolant from a nuclear reactor (heat source) and ocean water (heat sink) by heat transfer. The specific power is optimized by using thermodynamic software called CyclePad and computer graphics. (C) 1998 John Wiley & Sons, Inc.* C1 USN Acad, Dept Engn Mech, Annapolis, MD 21402 USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 1061-3773 J9 COMPUT APPL ENG EDUC JI Comput. Appl. Eng. Educ. PY 1998 VL 6 IS 1 BP 9 EP 13 PG 5 WC Computer Science, Interdisciplinary Applications; Education, Scientific Disciplines; Engineering, Multidisciplinary SC Computer Science; Education & Educational Research; Engineering GA ZA089 UT WOS:000072327800002 ER PT S AU Kassab, LL Greenwald, SJ AF Kassab, LL Greenwald, SJ BE Quisquater, JJ Deswarte, Y Meadows, C Gollmann, D TI Towards formalizing the Java security architecture of JDK 1.2 SO COMPUTER SECURITY - ESORICS 98 SE Lecture Notes in Computer Science LA English DT Article; Proceedings Paper CT 5th European Symposium on Research in Computer Security CY SEP 16-18, 1998 CL LOUVAIN LA NEUVE, BELGIUM AB The Java security architecture in the Java Development Kit 1.2 expands the current Java sandbox model, allowing finer-grained, configurable access control for Java code. This new security architecture permits more precise, yet flexible, protection for both remote code (loaded across a network connection) and local code (residing on the same machine running the Java Virtual Machine) developed using the Java programming language. Our formal model and analysis is intended to: (1) allow designers and implementers to understand and correctly use the protection provided by these security controls, and (2) provide guidance to a JVM implementor wishing to support these security controls. Access control decisions in Java are made based on the current execution context using stack introspection. To model this, we employ a state-based model that uses multiple access control matrices to model the security controls in JDK 1.2. We also present a safety analysis and discuss the effects of static and dynamic security policies for a given Java Virtual Machine. C1 USN, Res Lab, Ctr High Assurance Comp Syst, Washington, DC 20375 USA. RP USN, Res Lab, Ctr High Assurance Comp Syst, Washington, DC 20375 USA. EM kassab@itd.nrl.navy.mil; sjg6@gate.net NR 18 TC 2 Z9 2 U1 0 U2 1 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 3-540-65004-0 J9 LECT NOTES COMPUT SC PY 1998 VL 1485 BP 191 EP 207 PG 17 WC Computer Science, Software Engineering SC Computer Science GA BN96C UT WOS:000083673800013 ER PT J AU Kwon, YW Cunningham, RE AF Kwon, YW Cunningham, RE TI Comparison of USA-DYNA finite element models for a stiffened shell subject to underwater shock SO COMPUTERS & STRUCTURES LA English DT Article DE boundary element method; dynamic analysis; finite element modeling; fluid-structure interaction; stiffened shell; underwater shock ID INFINITE ELEMENTS; BOUNDARY AB A numerical study was conducted for simplified finite element modeling of stiffened structures under a dynamic loading. The study considerd submerged structures subject to an underwater explosion. The objective of this study was to develop a finite element modeling technique which is computationally efficient and still accurate in terms of the structural dynamic response. This paper investigated techniques for smearing of stiffeners, represenation of a cylindrical shell by a beam with surface of revolution (SOR), and interface of a cylindrical shell with a SOR beam. The advantage and disadvantage of those techniques in conjunction with an explicit time-integration scheme were also discussed. (C) 1997 Elsevier Science Ltd. C1 USN, Postgrad Sch, Dept Mech Engn, Monterey, CA 93943 USA. RP Kwon, YW (reprint author), USN, Postgrad Sch, Dept Mech Engn, Monterey, CA 93943 USA. NR 22 TC 18 Z9 23 U1 0 U2 4 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 JAN PY 1998 VL 66 IS 1 BP 127 EP 144 DI 10.1016/S0045-7949(97)00049-7 PG 18 WC Computer Science, Interdisciplinary Applications; Engineering, Civil SC Computer Science; Engineering GA YX438 UT WOS:000072040000012 ER PT B AU Nielsen, KE Durkee, PA AF Nielsen, KE Durkee, PA GP AMER METEOROL SOC AMER METEOROL SOC AMER METEOROL SOC AMER METEOROL SOC TI World-wide ship track occurrence observations SO CONFERENCE ON CLOUD PHYSICS LA English DT Proceedings Paper CT 14th Conference on Planned and Inadvertent Weather Modification CY AUG 17-21, 1998 CL EVERETT, WA SP Amer Meteorol Soc C1 USN, Postgrad Sch, Dept Meteorol, Monterey, CA 93943 USA. RP Nielsen, KE (reprint author), USN, Postgrad Sch, Dept Meteorol, Monterey, CA 93943 USA. NR 1 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 152 EP 154 PG 3 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BM52Y UT WOS:000079027100045 ER PT B AU Wang, Q Zuo, HC Wang, SP Zhao, CS Westphal, DL AF Wang, Q Zuo, HC Wang, SP Zhao, CS Westphal, DL GP AMER METEOROL SOC AMER METEOROL SOC AMER METEOROL SOC AMER METEOROL SOC TI A new turbulence closure model with explicit microphysics for marine stratocumulus SO CONFERENCE ON CLOUD PHYSICS LA English DT Proceedings Paper CT 14th Conference on Planned and Inadvertent Weather Modification CY AUG 17-21, 1998 CL EVERETT, WA SP Amer Meteorol Soc ID PLANETARY BOUNDARY-LAYER; RADIATIVE-TRANSFER; STRATUS C1 USN, Postgrad Sch, Dept Meteorol, Monterey, CA 93940 USA. RP Wang, Q (reprint author), USN, Postgrad Sch, Dept Meteorol, Monterey, CA 93940 USA. NR 9 TC 1 Z9 1 U1 0 U2 1 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 1998 BP 325 EP 328 PG 4 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BM52Y UT WOS:000079027100096 ER PT B AU Ericsen, T AF Ericsen, T GP IEEE IEEE TI Power electronics building blocks and potential power modulator applications SO CONFERENCE RECORD OF THE 1998 TWENTY-THIRD INTERNATIONAL POWER MODULATOR SYMPOSIUM LA English DT Proceedings Paper CT 23rd International Power Modulator Symposium CY JUN 22-25, 1998 CL RANCHO MIRAGE, CA SP Advisory Grp Electron Devices, Army Res Lab, Army Res Off, Air Force Wright Lab, Naval Surface Warfare Ctr, Sandia Natl Labs, Univ SO CA, Electron Devices Soc IEEE AB Power Electronic Building Blocks (PEBBs) are power processors. A PEBB is not a specific semiconductor material, not a device, nor a circuit topology. It is the search for the common electrical, mechanical and thermal denominators of all these, allowing integration of all these technologies. It is not; "one size fits all." There will be several blocks that will fit together to perform the majority of everyday power electronic jobs. Like a set of children's interlocking blocks, PEBBs will be a rational and simple set of blocks I and procedures that most any designer or architect can use to build electrical systems. The Office of Naval Research (ONR) is developing Power Electronic Building Blocks to achieve: increased power density, "user friendly" design ("plug and play" power modules), and multi-functionality. Digital controls, integrated with higher frequency and more robust power circuits, enable modular power systems with lower size, weight, and cost - while increasing performance. Although the day when solid-state will replace tubes in high-power modulator applications is still in the future, many near-term opportunities exist for PEBBs and associated technologies. This paper presents requirements, opportunities and issues for standardized power modules. First, an overview of the PEBB program is given. Then, opportunities are examined for technologies developed by the PEBB program. C1 Off Naval Res, Code 334, Arlington, VA 22217 USA. RP Ericsen, T (reprint author), Off Naval Res, Code 334, 800 N Quincy St, Arlington, VA 22217 USA. NR 5 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4244-5 PY 1998 BP 12 EP 15 DI 10.1109/MODSYM.1998.741179 PG 4 WC Engineering, Electrical & Electronic SC Engineering GA BM25Z UT WOS:000078189700004 ER PT S AU Schleher, DC AF Schleher, DC BE Matthews, MB TI Probabilistic adaptive CFAR SO CONFERENCE RECORD OF THE THIRTY-SECOND ASILOMAR CONFERENCE ON SIGNALS, SYSTEMS & COMPUTERS, VOLS 1 AND 2 SE CONFERENCE RECORD OF THE ASILOMAR CONFERENCE ON SIGNALS, SYSTEMS AND COMPUTERS LA English DT Proceedings Paper CT 32nd Asilomar Conference on Signals, Systems and Computers CY NOV 01-04, 1998 CL PACIFIC GROVE, CA SP Naval Postgrad Sch, Monterey, San Jose State Univ, San Jose, Monterey Bay Aquarium Res Inst, IEEE Signal Proc Soc AB False alarm regulation is a critical requirement in modern surveillance radars. Present techniques are susceptible to poor false alarm control when operated in non-Gaussian backgrounds representative of real world situations. The conventional log-t CFAR is shown to be highly sensitive to the inclusion of small amounts of receiver noise in addition to the Weibull clutter for which it is tuned. An adaptive log-t CFAR is described which, under certain conditions, provides an order of magnitude better false alarm control than the conventional log-t CFAR. This adaptive processor maintains false alarm regulation by estimating the probability distribution of the interference and hence, in concept, is independent of the interference probability distribution. C1 USN, Postgrad Sch, Monterey, CA 93943 USA. RP Schleher, DC (reprint author), USN, Postgrad Sch, Monterey, CA 93943 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 SN 1058-6393 BN 0-7803-5149-5 J9 CONF REC ASILOMAR C PY 1998 BP 431 EP 435 PG 5 WC Computer Science, Information Systems; Computer Science, Interdisciplinary Applications; Computer Science, Theory & Methods; Engineering, Electrical & Electronic; Telecommunications SC Computer Science; Engineering; Telecommunications GA BM43X UT WOS:000078743600080 ER PT S AU Ashraf, MA Cristi, R Tummala, M AF Ashraf, MA Cristi, R Tummala, M BE Matthews, MB TI A time series of decisions approach in detection systems SO CONFERENCE RECORD OF THE THIRTY-SECOND ASILOMAR CONFERENCE ON SIGNALS, SYSTEMS & COMPUTERS, VOLS 1 AND 2 SE CONFERENCE RECORD OF THE ASILOMAR CONFERENCE ON SIGNALS, SYSTEMS AND COMPUTERS LA English DT Proceedings Paper CT 32nd Asilomar Conference on Signals, Systems and Computers CY NOV 01-04, 1998 CL PACIFIC GROVE, CA SP Naval Postgrad Sch, Monterey, San Jose State Univ, San Jose, Monterey Bay Aquarium Res Inst, IEEE Signal Proc Soc AB Time series of decisions in detection systems enable us to integrate the individual sensor's decisions to improve the detection performance. This paper considers the problem of optimum fusion structure in time series of decisions detection systems. The optimum local fusion structure that minimize the total risk is derived. It is found that the optimum local fusion structure is the majority logic fusion strategy. The proposed structure is applied in case of a single sensor detection system with Gaussian and Exponentially distributed observations. Monte Carlo simulation is provided to evaluate the system performance. Significent performance improvement is achieved using the proposed structure. This structure enable us to exploit the benefits of data fusion even when we use a single sensor detection system. C1 USN, Postgrad Sch, Dept Elect & Comp Engn, Monterey, CA 93943 USA. RP Ashraf, MA (reprint author), USN, Postgrad Sch, Dept Elect & Comp Engn, Monterey, CA 93943 USA. NR 9 TC 0 Z9 0 U1 0 U2 8 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1058-6393 BN 0-7803-5149-5 J9 CONF REC ASILOMAR C PY 1998 BP 623 EP 627 PG 5 WC Computer Science, Information Systems; Computer Science, Interdisciplinary Applications; Computer Science, Theory & Methods; Engineering, Electrical & Electronic; Telecommunications SC Computer Science; Engineering; Telecommunications GA BM43X UT WOS:000078743600118 ER PT S AU Ciezki, JG Ashton, RW AF Ciezki, JG Ashton, RW BE Matthews, MB TI The application of a customized DSP board for the control of power electronic converters in a DC zonal electric distribution system SO CONFERENCE RECORD OF THE THIRTY-SECOND ASILOMAR CONFERENCE ON SIGNALS, SYSTEMS & COMPUTERS, VOLS 1 AND 2 SE Conference Record of the Asilomar Conference on Signals Systems and Computers LA English DT Proceedings Paper CT 32nd Asilomar Conference on Signals, Systems and Computers CY NOV 01-04, 1998 CL PACIFIC GROVE, CA SP Naval Postgrad Sch, Monterey, San Jose State Univ, San Jose, Monterey Bay Aquarium Res Inst, IEEE Signal Proc Soc AB In an attempt to enhance survivability and reduce cost, the U.S. Navy is currently investigating the implementation of a shipboard de power distribution architecture that contains a multitude of interconnected power converters. The authors document a customized DSP resource (the Universal Controller) that has been specially developed to satisfy the unique control requirements of high-voltage high switching frequency power converters that utilize algorithms requiring multiple input and output channels. In particular, the authors describe the attributes of the CPU and I/O boards of the Universal Controller then detail how the unit is used to control two paralleled dc-dc buck converters. C1 USN, Postgrad Sch, Monterey, CA 93943 USA. RP USN, Postgrad Sch, Monterey, CA 93943 USA. NR 12 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1058-6393 BN 0-7803-5148-7; 0-7803-5149-5 J9 CONF REC ASILOMAR C PY 1998 BP 1017 EP 1021 PG 5 WC Computer Science, Information Systems; Computer Science, Interdisciplinary Applications; Computer Science, Theory & Methods; Engineering, Electrical & Electronic; Telecommunications SC Computer Science; Engineering; Telecommunications GA BM43X UT WOS:000078743600192 ER PT S AU Larkin, MJ AF Larkin, MJ BE Matthews, MB TI Sensor fusion and classification of acoustic signals using Bayesian networks SO CONFERENCE RECORD OF THE THIRTY-SECOND ASILOMAR CONFERENCE ON SIGNALS, SYSTEMS & COMPUTERS, VOLS 1 AND 2 SE CONFERENCE RECORD OF THE ASILOMAR CONFERENCE ON SIGNALS, SYSTEMS AND COMPUTERS LA English DT Proceedings Paper CT 32nd Asilomar Conference on Signals, Systems and Computers CY NOV 01-04, 1998 CL PACIFIC GROVE, CA SP Naval Postgrad Sch, Monterey, San Jose State Univ, San Jose, Monterey Bay Aquarium Res Inst, IEEE Signal Proc Soc AB In order to maximize probability of detection and classification of a sonar contact, particularly in an adverse acoustic environment such as shallow water, sensor fusion is critical because (1) one sensor type may not he sufficient to defect ail target classes, and (2) statistical properties of the sensor fusion algorithm enhance classification performance beyond that achievable with the best individual sensor. We consider the problem of multiple sensor correlation and fusion using Bayesian networks in a hierarchical scheme, considering first two different active sonar waveforms, then combining active and passive sonar, and finally information from other sensors and sources. C1 USN, Undersea Warfare Ctr, Newport, RI 02841 USA. RP Larkin, MJ (reprint author), USN, Undersea Warfare Ctr, Code 3111, Newport, RI 02841 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1058-6393 BN 0-7803-5149-5 J9 CONF REC ASILOMAR C PY 1998 BP 1359 EP 1362 PG 4 WC Computer Science, Information Systems; Computer Science, Interdisciplinary Applications; Computer Science, Theory & Methods; Engineering, Electrical & Electronic; Telecommunications SC Computer Science; Engineering; Telecommunications GA BM43X UT WOS:000078743600256 ER PT S AU Parker, RE Tummala, M AF Parker, RE Tummala, M BE Matthews, MB TI Modeling of H.263 encoded low bitrate video traffic for tactical video conferencing applications SO CONFERENCE RECORD OF THE THIRTY-SECOND ASILOMAR CONFERENCE ON SIGNALS, SYSTEMS & COMPUTERS, VOLS 1 AND 2 SE CONFERENCE RECORD OF THE ASILOMAR CONFERENCE ON SIGNALS, SYSTEMS AND COMPUTERS LA English DT Proceedings Paper CT 32nd Asilomar Conference on Signals, Systems and Computers CY NOV 01-04, 1998 CL PACIFIC GROVE, CA SP Naval Postgrad Sch, Monterey, San Jose State Univ, San Jose, Monterey Bay Aquarium Res Inst, IEEE Signal Proc Soc AB Growing demand for networked video applications has led to increased interest in VER traffic since VER traffic allows statistical multiplexing to conserve bandwidth. However, transporting VER traffic poses challenges in guaranteeing QoS and efficiently utilizing resources relative to CBR traffic. Modeling VER traffic aids in estimating QoS metrics, evaluating scheduling algorithms, and determining statistical multiplexing gains. While most VER traffic models have focused on high-bandwidth traffic, we propose a traffic model for H.263 encoded video sequences, appropriate for low-bit-rare video. The traffic model uses a multi-state Markov chain representing a pseudo-histogram of observed bit-rates. To reduce correlation between multiplexed sequences and enhance multiplexer performance, each stream is deterministically smoothed over one frame length. C1 USN, Postgrad Sch, Dept Elect & Comp Engn, Monterey, CA 93943 USA. RP Parker, RE (reprint author), USN, Postgrad Sch, Dept Elect & Comp Engn, Monterey, CA 93943 USA. NR 12 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1058-6393 BN 0-7803-5149-5 J9 CONF REC ASILOMAR C PY 1998 BP 1626 EP 1630 PG 5 WC Computer Science, Information Systems; Computer Science, Interdisciplinary Applications; Computer Science, Theory & Methods; Engineering, Electrical & Electronic; Telecommunications SC Computer Science; Engineering; Telecommunications GA BM43X UT WOS:000078743600308 ER PT S AU Fargues, MP Duzenli, O AF Fargues, MP Duzenli, O BE Matthews, MB TI Dimension reduction issues in classification applications SO CONFERENCE RECORD OF THE THIRTY-SECOND ASILOMAR CONFERENCE ON SIGNALS, SYSTEMS & COMPUTERS, VOLS 1 AND 2 SE CONFERENCE RECORD OF THE ASILOMAR CONFERENCE ON SIGNALS, SYSTEMS AND COMPUTERS LA English DT Proceedings Paper CT 32nd Asilomar Conference on Signals, Systems and Computers CY NOV 01-04, 1998 CL PACIFIC GROVE, CA SP Naval Postgrad Sch, Monterey, San Jose State Univ, San Jose, Monterey Bay Aquarium Res Inst, IEEE Signal Proc Soc DE dimension reduction; wavelet; classification AB A simple type of projection pursuit scheme is discussed and applied to classification applications. The proposed scheme is used to significantly reduce the number of class features obtained from the wavelet packet decomposition of the signals to be classified. Results show this scheme can be used to classify underwater data without significant loss of performance. C1 USN, Postgrad Sch, ECE Dept, Monterey, CA 93943 USA. RP Fargues, MP (reprint author), USN, Postgrad Sch, ECE Dept, Code EC-Fa, Monterey, CA 93943 USA. NR 14 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1058-6393 BN 0-7803-5149-5 J9 CONF REC ASILOMAR C PY 1998 BP 1670 EP 1673 PG 4 WC Computer Science, Information Systems; Computer Science, Interdisciplinary Applications; Computer Science, Theory & Methods; Engineering, Electrical & Electronic; Telecommunications SC Computer Science; Engineering; Telecommunications GA BM43X UT WOS:000078743600316 ER PT S AU Conka, T Hippenstiel, RD Ha, TT AF Conka, T Hippenstiel, RD Ha, TT BE Matthews, MB TI Performance analysis of DPSK using post-detection selection combining over a Rayleigh fading channel SO CONFERENCE RECORD OF THE THIRTY-SECOND ASILOMAR CONFERENCE ON SIGNALS, SYSTEMS & COMPUTERS, VOLS 1 AND 2 SE CONFERENCE RECORD OF THE ASILOMAR CONFERENCE ON SIGNALS, SYSTEMS AND COMPUTERS LA English DT Proceedings Paper CT 32nd Asilomar Conference on Signals, Systems and Computers CY NOV 01-04, 1998 CL PACIFIC GROVE, CA SP Naval Postgrad Sch, Monterey, San Jose State Univ, San Jose, Monterey Bay Aquarium Res Inst, IEEE Signal Proc Soc AB The performance of a noncoherent Differential Phase Shift Keying (DPSK) receiver using Post-Detection Selection Combining over a Rayleigh fading channel is investigated. Post-Detection Selection Combining (PDSC) is evaluated and compared to Equal Gain Combining (EGC) and Selection Combining (SC). C1 USN, Postgrad Sch, Dept Elect & Comp Engn, Monterey, CA 93943 USA. RP Conka, T (reprint author), USN, Postgrad Sch, Dept Elect & Comp Engn, Monterey, CA 93943 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 SN 1058-6393 BN 0-7803-5149-5 J9 CONF REC ASILOMAR C PY 1998 BP 1768 EP 1772 PG 5 WC Computer Science, Information Systems; Computer Science, Interdisciplinary Applications; Computer Science, Theory & Methods; Engineering, Electrical & Electronic; Telecommunications SC Computer Science; Engineering; Telecommunications GA BM43X UT WOS:000078743600334 ER PT B AU Agarwala, VS AF Agarwala, VS BE Khanna, AS Totlani, MK Singh, SK TI Corrosion 'health' monitoring systems for reduced maintenance/repair and increased system reliability SO CORROSION AND ITS CONTROLS, VOLS I AND II LA English DT Proceedings Paper CT International Conference on Corrosion (CORCON 97) CY DEC 03-06, 1997 CL NEHRU CTR, MUMBAI, INDIA SP NACE Int India Sect, IIM, Mumbai Chapter, SAEST, MFAI HO NEHRU CTR AB Corrosion is a major factor which undermines "health" of an aircraft and reduces its service-life. It is insidious and if not detected and controlled in time could affect both the functional and structural integrity of aircraft system. To detect and monitor hidden corrosion, primarily two technologies have: been discussed. The first one is based on the use of "smart materials" for corrosion sensing or detection. These materials are highly conjugated organic chemicals, which become optically active (fluorescence) during oxidation or reaction with a corrosion product. A number of compounds have been identified or synthesized which produce fluorescence when complexed with metal ions/oxides or oxidized. These fluorescent chemicals have been applied either as sprays or incorporated in the coating to show early signs of corrosion when observed under UV light. The second technology is based on the concept of monitoring in-situ environmental corrosivity through use of a galvanic (electrochemical) thin-film sensor. It employs the principles of galvanic corrosion where an active metal is exposed to corrosive elements of the environment and its rate of corrosion is measured as the magnitude of galvanic current produced when coupled with a noble metal. These sensors have been tested on aircraft (operational and stored), in hidden structures, ammunitions and electronic bays, and under coatings and sealants. A more rugged variety of this detection concept has been also used in the evaluation of corrosivity of hydraulic fluids and lubricants. C1 USN, Air Syst Command, Air Vehicle Dept, Patuxent River, MD 20670 USA. RP Agarwala, VS (reprint author), USN, Air Syst Command, Air Vehicle Dept, Patuxent River, MD 20670 USA. NR 0 TC 0 Z9 0 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA SARA BURGERHARTSTRAAT 25, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS BN 0-444-82916-4 PY 1998 BP 140 EP 150 PG 11 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA BL03F UT WOS:000074086500013 ER PT J AU Reed, RP Golda, M AF Reed, RP Golda, M TI Properties of cold-to-warm support straps SO CRYOGENICS LA English DT Article; Proceedings Paper CT 8th International Cryogenics Materials Conference CY SEP 23-25, 1996 CL GENEVA, SWITZERLAND SP CERN, European Org Nucl Res DE composite straps; tensile/fatigue properties; low temperatures ID COMPOSITES AB In cryogenic equipment, composite straps are sometimes used for structural support and thermal isolation of the cryogenic system from the warm structure. Composite straps reinforced with unidirectional fibres are loaded in tension. In straps with carbon fibre reinforcement, very strong tensile strengths (up to 3.5 GPa) have been reported. Recent studies, at 295, 76, and 4 K, have clarified the effects of spool diameter on the strengths of carbon fibre reinforced straps. For straps reinforced with E-and S-glass, carbon, and alumina fibres, this paper reviews the relevant mechanical and thermal properties from 295 to 4 K: elastic, tensile, fatigue, thermal contraction, and thermal conductivity. Published by Elsevier Science Ltd. C1 Cryogen Mat Inc, Boulder, CO 80303 USA. USN, Ctr Surface Warfare, Elect Machinery Technol Branch, Machinery Res & Dev Directorate,Carderock Div, Annapolis, MD 21402 USA. RP Reed, RP (reprint author), Cryogen Mat Inc, 2625 Lliff, Boulder, CO 80303 USA. NR 11 TC 1 Z9 1 U1 1 U2 2 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0011-2275 J9 CRYOGENICS JI Cryogenics PD JAN PY 1998 VL 38 IS 1 BP 39 EP 42 DI 10.1016/S0011-2275(97)00107-0 PG 4 WC Thermodynamics; Physics, Applied SC Thermodynamics; Physics GA ZP201 UT WOS:000073727900007 ER PT B AU Soulen, RJ Francavilla, TL Gubser, DU Waltman, D Sondergaard, N Chafe, J AF Soulen, RJ Francavilla, TL Gubser, DU Waltman, D Sondergaard, N Chafe, J BE Guobang, C Steimle, FW Huang, ZX Yan, Q Zhang, L TI Recent developments for ship propulsion using high temperature superconductors SO CRYOGENICS AND REFRIGERATION - PROCEEDINGS OF ICCR 98 LA English DT Proceedings Paper CT ICCR 98 Meeting CY APR 21-24, 1998 CL ZHEJIANG UNIV, HANGZHOU, PEOPLES R CHINA SP Chinese Assoc Refrigerat, Int Inst Refrigerat, Zhejiang Jiecka Mech & Elect Equipment Co Ltd, Natl Nat Sci Fdn China, Natl Commiss Educ China HO ZHEJIANG UNIV AB A collaboration between the Naval Research Laboratory (NRL) and the Naval Surface Warfare Center (NSWC), along with industrial partners American Superconductor Corp. (ASC) and Intermagnetics General Corp. (IGC), has been established in order to produce high-transition temperature superconducting (HTS) motors for ship propulsion.In the latest tests, a homopolar motor wound from coils of Bi2Sr2Ca2Cu3O tapes has generated the following horsepower (hp) as a function of temperature: 320 hp (240 kW) at 4.2 K, 230 hp (172 kW) at 27 K, and 104 hp (78 kW) at T = 77 K. C1 USN, Res Lab, Washington, DC 20375 USA. RP Soulen, RJ (reprint author), USN, Res Lab, Code 6344, Washington, DC 20375 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU WORLD PUBLISHING CORPORATION PI BEIJING PA 137 CHAONEI DAJIE, BEIJING 100010, PEOPLES R CHINA BN 7-80003-414-3 PY 1998 BP 510 EP 513 PG 4 WC Thermodynamics; Engineering, Mechanical SC Thermodynamics; Engineering GA BL24C UT WOS:000074797900115 ER PT B AU Soulen, RJ Osofsky, MS Chrisey, DB Horwitz, JS Koller, D Stroud, RM Kim, J Eddy, CR Byers, JM Woodfield, BF AF Soulen, RJ Osofsky, MS Chrisey, DB Horwitz, JS Koller, D Stroud, RM Kim, J Eddy, CR Byers, JM Woodfield, BF BE Guobang, C Steimle, FW Huang, ZX Yan, Q Zhang, L TI Suppression of superconductivity by injection of spin-polarized current SO CRYOGENICS AND REFRIGERATION - PROCEEDINGS OF ICCR 98 LA English DT Proceedings Paper CT ICCR 98 Meeting CY APR 21-24, 1998 CL ZHEJIANG UNIV, HANGZHOU, PEOPLES R CHINA SP Chinese Assoc Refrigerat, Int Inst Refrigerat, Zhejiang Jiecka Mech & Elect Equipment Co Ltd, Natl Nat Sci Fdn China, Natl Commiss Educ China HO ZHEJIANG UNIV AB We present results demonstrating that the superconductivity in thin films can be strongly influenced by the injection of a spin-polarized current from a magnetic material. The effect has been found to occur in both low T-c (Sn) and high T-c (YBa2Cu3O7-delta) superconductors when either a ferromagnetic material, permalloy (Ni0.8Fe0.2), or a collosal magnetic material LaSrMnO is used as the source of spin polarization. Control experiments showed that unpolarized current from a nonmagnetic metal had comparatively little effect on the same superconductors. A phenomenological model in which the energy gap of the superconductor is strongly perturbed by the presence of excess spin polarized electrons is found to mimic the experimental results. C1 USN, Res Lab, Washington, DC 20375 USA. RP Soulen, RJ (reprint author), USN, Res Lab, Washington, DC 20375 USA. RI Stroud, Rhonda/C-5503-2008; Osofsky, Michael/A-1050-2010 OI Stroud, Rhonda/0000-0001-5242-8015; NR 0 TC 0 Z9 0 U1 0 U2 0 PU WORLD PUBLISHING CORPORATION PI BEIJING PA 137 CHAONEI DAJIE, BEIJING 100010, PEOPLES R CHINA BN 7-80003-414-3 PY 1998 BP 514 EP 517 PG 4 WC Thermodynamics; Engineering, Mechanical SC Thermodynamics; Engineering GA BL24C UT WOS:000074797900116 ER PT S AU Karwacki, F Cui, H Sanzari, M Hasan, Z AF Karwacki, F Cui, H Sanzari, M Hasan, Z BE Fischer, RE Germann, LM Hatheway, AE McConnell, M Smith, WJ TI Novel high-frequency QW optical modulator based on surface effects SO CURRENT DEVELOPMENTS IN OPTICAL DESIGN AND ENGINEERING VII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Current Developments in Optical Design and Engineering VII CY JUL 22-23, 1998 CL SAN DIEGO, CA SP SPIE Int Soc Opt Engn DE optical modulator; quantum well structure; Franz-Keldysh; optical birefringence AB This paper is directed at the analysis of the basic operating principles, design, operation, and performance of a different type of optical modulator, capable of large phase modulation through the change of the optical index of refraction. This is achieved by modification of waveguide boundary conditions by incorporating quantum wells that can be charged or emptied of electrons at the planar dielectric waveguide boundaries, by application of gate voltages. Such an unconventional way of achieving the desired modifications in the optical refractive index will provide attractive alternative and more versatility than the conventional means of realizing such modifications, such as electrooptical effects (electroabsorption, Franz-Keldysh effect, optical birefringence), carrier induced effects (band filling, band gap renormalization), and free carrier absorption (plasma effect). Furthermore, the technology (e.g. molecular beam epitaxy, metalorganic chemical vapor deposition, ion beam etching, and other micro machining techniques) of fabrication of these new devices is already in place, so the proposed concept can be tested to facilitate further development. Based on these projections, we propose a planar-based dielectric waveguide having confined electrons in quantum wells at the boundaries. Microstructure devices made from semiconductors, e.g. CoSi2 or GaAs/Ga1-xAlxAs, are the most practically fabricated in the form of planar structures. Moreover, it is well adapted for various gate electrode geometries for activation and control of the quantum wells. C1 USN, Air Warfare Ctr, Patuxent River, MD USA. RP Karwacki, F (reprint author), USN, Air Warfare Ctr, Code 0322, Patuxent River, MD 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 0-8194-2884-1 J9 P SOC PHOTO-OPT INS PY 1998 VL 3429 BP 117 EP 122 DI 10.1117/12.328534 PG 6 WC Optics SC Optics GA BM07K UT WOS:000077547400015 ER PT J AU Robinson, GE AF Robinson, GE TI Authoritarianism with a Palestinian face SO CURRENT HISTORY LA English DT Article AB "For some observers there is nothing surprising about the creation of another Arab dictatorship. Why should Palestine and the Palestinian Authority be any different from so many other countries in the Arab world? Such arguments, generally focusing on an essentialist, antidemocratic understanding of Arab-Islamic political culture, miss the point of the political-not cultural-origins of PA authoritarianism". C1 USN, Postgrad Sch, Monterey, CA 93940 USA. Univ Calif Berkeley, Ctr Middle Eastern Studies, Berkeley, CA 94720 USA. RP Robinson, GE (reprint author), USN, Postgrad Sch, Monterey, CA 93940 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU CURRENT HIST INC PI PHILADELPHIA PA 4225 MAIN ST PO BOX 4647, PHILADELPHIA, PA 19127 USA SN 0011-3530 J9 CURR HIST JI Curr. Hist. PD JAN PY 1998 VL 97 IS 615 BP 13 EP 18 PG 6 WC International Relations; Political Science SC International Relations; Government & Law GA YN490 UT WOS:000071173800003 ER PT J AU Murphy, GS Echeverria, P AF Murphy, GS Echeverria, P TI Treatment of gastrointestinal infections SO CURRENT OPINION IN GASTROENTEROLOGY LA English DT Article ID VIBRIO-CHOLERAE; DIARRHEA; CIPROFLOXACIN AB The past year has seen the continued spread of antimicrobial drug resistance to important gastrointestinal pathogens; however, reports have offered new ways to use the available antibiotics, and new therapies and vaccines have been tried. Single-dose ciprofloxacin was as effective as doxycycline in cholera treatment, A somatostatin analogue and a Ei-hydroxytryptamine receptor antagonist reduced secretory diarrhea in preliminary studies. A 5-day course of azithromycin was effective in the treatment of shigellosis. Ciprofloxacin resistance was reported in higher frequencies of Salmonella typhi, Escherichia coli, and Campylobacter jejuni isolates, Vaccine trials had partial success against cholera and shigellosis. Treatment guidelines have been claried for Clostridium difficile-associated diarrhea, yet there is still a need for better ways to treat multidrug resistant enteric infections and for more effective vaccines to prevent them. C1 USN, Med Res Inst, Natl Naval Med Ctr, Bethesda, MD 20889 USA. RP Murphy, GS (reprint author), USN, Med Res Inst, Natl Naval Med Ctr, Bethesda, MD 20889 USA. NR 18 TC 1 Z9 1 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 USA SN 0267-1379 J9 CURR OPIN GASTROEN JI Curr. Opin. Gastroenterol. PD JAN PY 1998 VL 14 IS 1 BP 77 EP 82 DI 10.1097/00001574-199801000-00014 PG 6 WC Gastroenterology & Hepatology SC Gastroenterology & Hepatology GA YT673 UT WOS:000071630600014 ER PT B AU Matic, P Kee, A AF Matic, P Kee, A BE Carpinteri, A Brebbia, CA TI Plastic flow percolation across a microstructure with pores SO DAMAGE AND FRACTURE MECHANICS: COMPUTER AIDED ASSESSMENT AND CONTROL LA English DT Proceedings Paper CT 5th International Conference on Computer Aided Assessment and Control of Localized Damage and Fracture Mechanics CY 1998 CL BOLOGNA, ITALY SP Wessex Inst Technol, Politecnico Torino, Dipartimenti Ingeneria Strutturale, Italy, Int Soc Boundary Elements AB A method to estimate the yield surface of porous metals, by identifying evolution of local yield connectivity and the onset of local yield percolation across the microstructure from finite element analyses, is investigated. The finite element analyses are used to model the types of pore morphologies that have been observed in porous metals. Linear superposition of basis deformation cases is used to generate arbitrary applied elastic biaxial deformation states used to estimate the yield surface, in place of more costly and time consuming nonlinear analyses. C1 USN, Res Lab, Mech Mat Branch, Washington, DC 20375 USA. RP Matic, P (reprint author), USN, Res Lab, Mech Mat Branch, Code 6382, Washington, DC 20375 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU COMPUTATIONAL MECHANICS PUBLICATIONS LTD PI SOUTHAMPTON PA ASHURST LODGE, SOUTHAMPTON S04 2AA, HANTS, ENGLAND BN 1-85312-583-0 PY 1998 BP 525 EP 534 PG 10 WC Engineering, Mechanical; Mechanics; Metallurgy & Metallurgical Engineering; Materials Science, Characterization & Testing; Materials Science, Composites SC Engineering; Mechanics; Metallurgy & Metallurgical Engineering; Materials Science GA BM17B UT WOS:000077898100051 ER PT S AU Creusere, CD AF Creusere, CD BE Storer, JA Cohn, M TI Successive coefficient refinement for embedded lossless image compression SO DCC '98 - DATA COMPRESSION CONFERENCE SE IEEE DATA COMPRESSION CONFERENCE LA English DT Proceedings Paper CT Data Compression Conference CY MAR 03-APR 01, 1998 CL SNOWBIRD, UT SP IEEE Comp Soc, Tech Comm Comp Commun C1 USN, Warfare Ctr, Weap Div, China Lake, CA 93555 USA. RP Creusere, CD (reprint author), USN, Warfare Ctr, Weap Div, China Lake, CA 93555 USA. NR 0 TC 0 Z9 0 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 SN 1068-0314 BN 0-8186-8406-2 J9 IEEE DATA COMPR CONF PY 1998 BP 539 EP 539 DI 10.1109/DCC.1998.672262 PG 1 WC Computer Science, Information Systems; Computer Science, Theory & Methods SC Computer Science GA BK74C UT WOS:000073308700069 ER PT J AU Coale, KH Johnson, KS Fitzwater, SE Blain, SPG Stanton, TP Coley, TL AF Coale, KH Johnson, KS Fitzwater, SE Blain, SPG Stanton, TP Coley, TL TI IronEx-I, an in situ iron-enrichment experiment: Experimental design, implementation and results SO DEEP-SEA RESEARCH PART II-TOPICAL STUDIES IN OCEANOGRAPHY LA English DT Article ID EQUATORIAL PACIFIC-OCEAN; BASIN TRACER EXPERIMENT; SUB-ARCTIC PACIFIC; PHYTOPLANKTON PHOTOSYNTHESIS; SULFUR-HEXAFLUORIDE; NATURAL-WATERS; CHEMILUMINESCENCE DETECTION; FERTILIZATION EXPERIMENT; MARINE-PHYTOPLANKTON; DISSOLVED IRON AB An in situ iron-enrichment experiment near the Galapagos Islands was performed in October 1993. Here we report the theoretical and practical considerations of creating such a patch of iron-enriched surface water, as well as the strategies employed for the detection of the patch and the biological and chemical signals which developed, in an area dominated by advective processes. Physical and chemical models were used to predict the speciation, solubility, and the final concentration of iron in surface waters injected with acidic iron sulfate. A trial injection off the California coast in which 800 L of a 0.5 M FeSO4 were introduced into the ship's wake over a 1.5 km(2) area, was used to test these predictions. Iron concentrations were determined continually onboard during the initial experiment as the ship steamed in transects through the enriched patch. The results indicate excellent spatial agreement with model predictions and final concentrations that were consistent with the chemical model. However, the use of a Cartesian coordinate system during injection resulted in an extremely compressed, heterogeneous patch. Results from this preliminary experiment were then applied towards the development and implementation of the first open ocean iron enrichment experiment (IronEx I) near the Galapagos Islands in October 1993. The development and results of these methodologies are presented. In the IronEx I equatorial experiment, a Lagrangian coordinate system was established using a drogued buoy (equipped with GPS and packet radio) and the iron-enriched area (64 km(2) containing 443 kg of Fe) was tagged with the inert chemical tracer sulfurhexafluoride (SF6). This strategy resulted in a fairly rectangular, homogeneous enriched patch initially detectable by both Fe and SF, determination. Shipboard analysis and airborne observations confirmed good spatial agreement between the Lagrangian drifter and the biological and chemical signatures in the patch. Biological and chemical sampling of the enriched area showed an increase in chlorophyll, primary production, biomass and photosynthetic energy conversion efficiency relative to waters outside the patch, supporting the hypothesis that iron limits phytoplankton growth and biomass in a 'bottom up' manner in this area. The ability to create a coherent patch and track it over time led to this first open-ocean test of the iron hypothesis. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 Moss Landing Marine Labs, Moss Landing, CA 95039 USA. Monterey Bay Aquarium Res Inst, Moss Landing, CA 95039 USA. Inst Univ Europeen Mer, CNRS, URA D1513, F-29275 Brest, France. USN, Postgrad Sch, Monterey, CA 93943 USA. Univ Maryland, Horn Point Environm Labs, Cambridge, MD 21613 USA. RP Coale, KH (reprint author), Moss Landing Marine Labs, Pob 450, Moss Landing, CA 95039 USA. RI blain, stephane/F-6917-2010; Johnson, Kenneth/F-9742-2011 OI blain, stephane/0000-0002-5234-2446; Johnson, Kenneth/0000-0001-5513-5584 NR 84 TC 46 Z9 52 U1 0 U2 25 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0967-0645 J9 DEEP-SEA RES PT II JI Deep-Sea Res. Part II-Top. Stud. Oceanogr. PY 1998 VL 45 IS 6 BP 919 EP 945 DI 10.1016/S0967-0645(98)00019-8 PG 27 WC Oceanography SC Oceanography GA 137ZG UT WOS:000076946500002 ER EF