| Sum Frequency Generation of Dual-Wavelength Nd. YAP Laser in LiIO3 Crystal |
29 MAR 95 |
9 pages |
| Authors:
Yuping Zhou; Hongyuan Shen; NATIONAL AIR INTELLIGENCE CENTER WRIGHT-PATTERSON AFB OH
|
 | Based on Sellmeier's equation for LiIO3 crystal, the phase-matched condition for sum-frequency generation of 1.0795 micrometers and 1.3414 micrometers dual wavelength Nd:YAP laser has been calculated. The calculated results agree well with the experimental ones. The CW and pulsed 0.5981 micrometers sum-frequency radiation have been achieved for the first time. jg p.4 ANNOTATION: Sum Frequency Generation of Dual-Wavelength Nd. YAP Laser in L1ID3 Crystal. --Translation. |
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| Photo-Refractive Bi12Si020-Spatial Light Modulator |
27 MAR 95 |
13 pages |
| Authors:
Zhao Mingjun; Li Yulin; Wang Zhao; NATIONAL AIR INTELLIGENCE CENTER WRIGHT-PATTERSON AFB OH
|
| This paper uses non-degenerate and degenerate multi-wave mixing frequencies of the photo-refractive Bi12SiO20 crystal to create incoherent - coherent conversions; wavelength conversion and image subtraction between coherent and incoherent images, and thus experimental results are so given. jg p.2 ANNOTATION: Photo-Refractive Bi12Si020-Spatial Light Modulator. --Translation. |
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| Characterizaticr of Solid State Laser and Nonlinear Optical Materials |
02 FEB 95 |
289 pages |
| Authors:
Jin-Joo Song; OKLAHOMA STATE UNIV STILLWATER CENTER FOR LASER RESEARCH
|
| Optical properties of materials having applications in solid state laser systems were investigated. The work was divided into two areas based on the materials useful in the different methods for obtaining frequency agility: narrow line emitters with multiple lasing channels and nonlinear optical materials. In the first category the spectral dynamics and lasing properties of a variety of materials such as fluoride and oxide crystals and glasses codoped with two ... |
|
| Characterization of Solid State Laser and Nonlinear Optical Materials |
02 FEB 95 |
288 pages |
| Authors:
Jin-Joo Song; OKLAHOMA STATE UNIV STILLWATER CENTER FOR LASER RESEARCH
|
| Optical properties of materials having applications in solid state laser systems were investigated. The work was divided into two areas based on the materials useful in the different methods for obtaining frequency agility: narrow line emitters with multiple lasing channels and nonlinear optical materials. In the first category the spectral dynamics and lasing properties of a variety of materials such as fluoride and oxide crystals and glasses codoped with two ... |
|
| Studies of C60, C70 and Other Fullerenes: Synthesis, Derivatization, Electrochemistry, Lubricant Properties and New Composite Materials |
FEB 95 |
37 pages |
| Authors:
R. E. Smalley; J. L. Margrave; R. H. Hauge; L. J. Wilson; W. E. Billups; ARMY FOREIGN SCIENCE AND TECHNOLOGY CENTER CHARLOTTESVILLE VA
|
| New designs for fullerene generators have been developed, including systems for producing endohedral species with metals inside the C60 or C70 cages. Also, focussed solar energy has been utilized for fullerene production. Electrochemical studies have led to the identification of C60(-1), C60(-2), C60(-6) ions and utilized for preparation of superconducting K3C60. Birch reductions of C60 and C70 led to C60H30 and C70H30 respectively. Adducts of C60 with tetraphenylcyclopentadienone and with ... |
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| Self Stressing Test Structure Cells |
FEB 95 |
106 pages |
| Authors:
Vance C. Tyree; UNIVERSITY OF SOUTHERN CALIFORNIA MARINA DEL REY INFORMATION SCIENCES INST
|
| This report addresses the work performed to design on chip reliability prognostics for purposes of monitoring fielded integrated circuits for degradation due to the failure mechanisms of oxide breakdown, electromigration, and hot carrier degradation. The self stressing test structure cells are self-contained standard cells that include the test structure, stressing, and monitoring circuitry and a boundary scan interface to be used with the IEEE 1149.1 boundary scan Test Access Port. ... |
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| Morphology Studies of CHDI-Based Urethane by Synchrotron X-Ray Diffraction |
FEB 95 |
57 pages |
| Authors:
C. R. Desper; Catherine A. Byrne; Yingjie Li; Benjamin Chu; ARMY RESEARCH LAB WATERTOWN MA MATERIALS DIRECTORATE
|
| Urethane elastomers having hard segments based on CHDI (trans-1,4- diisocyanatocyclohexane) and BD(1 ,4-butanediol) are notable for their high softening temperatures and low hysteretic heat buildup. Experimental studies as a function of temperature using both wide- and small-angle X-ray diffraction of a series of such elastomers, incorporating PTMO (poly(tetramethylene oxide) ) soft segments, reveal the persistence of hard segment microdomains up to 275 deg C. These hard segment microdomains appear to ... |
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| Correlation of Wafer Level QA Tests with Functional Device Yield and Accelerated Life Test Results |
FEB 95 |
49 pages |
| Authors:
Vance C. Tyree; UNIVERSITY OF SOUTHERN CALIFORNIA MARINA DEL REY INFORMATION SCIENCES INST
|
| This report covers work that was to correlate wafer level test structure tests with life tests by utilizing test structures collocated with a RAM-like device. Wafer level tests for oxide breakdown, electromigration, and hot carrier degradation were conducted on a total of six wafer lots from three vendors. Functional testing of the RAM-like device yielded just over six hundred devices to be packaged for the life test. The data from ... |
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| Lithium Ion Aqueous Cells |
FEB 95 |
19 pages |
| Authors:
Edward J. Plichta; Wishvender K. Behl; ARMY RESEARCH LAB FORT MONMOUTH NJ
|
| Lithium ion aqueous cells were investigated using lithium intercalating compounds as anodes and cathodes. The aqueous electrolyte consisted of 4 to 5 molar solutions of either lithium perchlorate or lithium nitrate which contained lithium hydroxide in millimolar amounts to make the solutions slightly basic with a pH of about 8.5. Several electrode combinations were evaluated using lithium intercalating compounds such as lithium cobalt oxide and lithium manganese oxide as cathodes ... |
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| High Rate Rechargeable Lithium Cells Employing Lithium Ion Conducting Solid Electrolytes |
FEB 95 |
16 pages |
| Authors:
Edward J. Plichta; Wishvender K. Behl; ARMY RESEARCH LAB FORT MONMOUTH NJ
|
| Results are presented on high temperature solid state cells employing 50:50 weight percent lithium germanium vanadium oxide-lithium iodide. The incorporation of lithium iodide in lithium germanium vanadium oxide resulted in higher pellet conductivities and improved the high rate performance of the solid state cells. The cells were comprised of a lithium-aluminum or lithium-silicon alloy as the anode and a CVD thin film of titanium disulfide as the cathode. The cells ... |
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| Chromic Oxide Coatings by Thermal Decomposition of Chromic Acid Anhydride (CRO3). |
10 JAN 1995 |
|
| Authors:
William A. Ferrando; DEPARTMENT OF THE NAVY WASHINGTON DC
|
 | A diamond, ceramic, metal, or metal alloy surface is coated with molten Cr03. The coated surface is then heated in air at a temperature of from about 200 C. to 250 C. until the molten CrO3 coating is converted into a black, powdery adherent coating of Cr0. |
|
| Fellowship in Physics |
02 JAN 95 |
11 pages |
| Authors:
A. J. Sievers; CORNELL UNIV ITHACA NY LAB OF ATOMIC AND SOLID STATE PHYSICS
|
| The relaxation of molecular impurities in glasses has been gaining attention in recent years, partly due to the availability of novel spectroscopic techniques in the infrared region, including the development of powerful tunable infrared lasers needed to excite the vibrational transitions that are about 4 orders of magnitude weaker than electronic transitions. In general, glassy hosts offer the possibility to study the influence of a distribution the local environments on ... |
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| Materials Science and Fabrication of YBCO-SrTi(1-x)Nb(x)03-YBCO Device Structures |
95 |
6 pages |
| Authors:
Shang Hou; STATE UNIV OF NEW YORK AT STONY BROOK
|
| As described in our proposal for making YBCO/SrTiNbO/YBCO junctions, the success of this project relies on work in three different thrusts: Growth of high quality, ultra-thin high-quality YBCO films. Acquisition of metallically doped SrTiO3 substrates with high structural quality. The fabrication and characterization of S-N-S Josephson structure based on YBCO/SrTiNbO heteroepitaxy. While there has been encouraging progress in the thin film growth part, problems were found in obtaining metallically doped ... |
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| Josephson Break Junction Thin Film Device. |
27 DEC 1994 |
|
| Authors:
Ignacio M. Perez; William R. Scott; DEPARTMENT OF THE NAVY WASHINGTON DC
|
| A Josephson break junction device suitable for highly sensitive electronic detecting systems. A superconductor film such as YBa2Al3O7 is deposited on a substrate such as a single-crystal MgO. The film is fractured across a narrow strip by at least one indentation in the substrate juxtaposed from the strip to form a break junction. A transducer is affixed to the substrate for applying a bending movement to the substrate to regulate ... |
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| A Cluster Beam Study of Boron Oxide Chemistry With HF |
26 DEC 94 |
38 pages |
| Authors:
J. Smolanoff; A. Lapicki; S. Anderson; STATE UNIV OF NEW YORK AT STONY BROOK DEPT OF CHEMISTRY
|
| Using an improved version of the Cluster Beam technique, we have probed the chemistry of B(x)O(y)H(z)+ clusters with HF as a function of the B:O:H stoichiometry of the cluster reactant. Reactant compositions were varied from pure boron to stoichiometric oxide, with and without added hydrogen. Boron oxide clusters react with HF at about 50% efficiency and the collision energy dependence suggests that the reaction is sterically hindered, i.e. reaction occurs ... |
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| Analytical Electron Microscopy of Nanometer-Sized Particles |
19 DEC 94 |
18 pages |
| Authors:
Stephen B. Rice; MCCRONE ASSOCIATES INC WESTMONT IL
|
| During the past quarter, despite lengthy downtime for the JEOL 4000FX, two aspects of our research plan were initiated: microdiffraction and the effects of prolonged beam exposure on the EELS signature of U oxides. While obtaining microdiffraction patterns, it was recognized that high resolution electron microscope images can be obtained on thin sections produced by ultramicrotomy. |
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| Influences of Film Structures on Laser Damage Thresholds |
15 DEC 94 |
14 pages |
| Authors:
Wu Zhouling; Fan Zhengxiu; NATIONAL AIR INTELLIGENCE CENTER WRIGHT-PATTERSON AFB OH
|
| This article takes TiO2/SiO2 and ZrO2/SiO2 film systems as examples and studies the influences of different film structures. It combines studies on measurements of optical Iosses and the effects of protective film thicknesses, making a preliminary probe into laser damage mechanisms as associated with optical thin films. (MM) ANNOTATION: Influences of Film Structures on Laser Damage Thresholds, -- Translation. |
|
| Pyronol Torch. |
13 DEC 1994 |
|
| Authors:
George L. Hart; Edwin L. McCluer; Alexander G. Rozner; William R. Walton; James C. Waldron; DEPARTMENT OF THE NAVY WASHINGTON DC
|
| A pyrotechnic, molten metal jet torch which employs a loose pyrotechnic starter powder such as (1) magnesium powder, or an intimate mixture of (2) Mg and CuO, (3) Mg and Fe2O3, (4) Mg and Co3O4, (5) Al and CuO, or (6) Al and Fe2O3 powders which are capable of being ignited by a conventional military incendiary grenade fuse and which generated enough heat to ignite pyronol pellets which are pressed ... |
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| Total Ionizing Dose Effects in MOSFET Devices at 77 K |
DEC 94 |
126 pages |
| Authors:
Kevin J. Daul; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING
|
| Total ionizing dose effects on thermal oxide and reoxidized nitrided oxide (RNO) MOSFET devices at 77 K were studied. The MOSFETs were immersed in liquid nitrogen and irradiated, using a Co-60 source, up to 1 Mrad(Si) at a dose rate of 107 rads(Si)/sec. Drain current-gate voltage characteristics were obtained and used to determine threshold voltage and transconductance. At 77 K the subthreshold slopes indicated no observed buildup of interface states ... |
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| Atomic Layer Epitaxy of Group IV Materials: Surface Processes, Thin Films, Devices and Their Characterization |
DEC 94 |
54 pages |
| Authors:
Robert F. Davis; S. Bedair; N. A. El-Masry; J. T. Glass; S. King; NORTH CAROLINA STATE UNIV AT RALEIGH DEPT OF MATERIALS SCIENCE AND ENGINEERING
|
| Residual surface contaminants were removed from vicinal 6H-SiC(0001) surfaces in UHV via high temperature annealing in SiH4. Characterization via AES, EELS, LEED, XPS, and UPS was conducted. At T>850 deg C, the surface oxide was rapidly removed. Exposure to approx. 400 Langmuir (10(exp-6) Torr(dot)liter/ s) of SiH4 resulted in complete surface oxide removal and a nearly stoichiometric (l x l) 6H-SiC surface suitable for ALE of SiC. Further exposure resulted ... |
|
| Metallurgical and Materials Transactions. Volume 25A, Number 12 |
DEC 94 |
331 pages |
| Authors:
CARNEGIE-MELLON UNIV PITTSBURGH PA
|
| METALLURGICAL AND MATERIALS TRANSACTIONS publishes contributions on all aspects of research and significant engineering advances in materials science and metallurgy. Approved manuscripts will be published according to subject matter in Section A or B. Metallurgical and Materials Transactions A publishes contributions on all aspects of physical metallurgy and materials science, with a special emphasis on relationships among the processing, structure, and properties of materials. (MM) |
|
| Investigation of Aging Effects from High Voltage Profiles in Ceramic Phase Shifter Materials |
DEC 94 |
15 pages |
| Authors:
S. Stowell; L. C. Sengupta; E. Ngo; M. E. O'Day; R. Lancto; ARMY RESEARCH LAB WATERTOWN MA MATERIALS DIRECTORATE
|
| Ceramic composite materials comprised of Ba(0.60)Sr(0.40)TiO3 and Alumina and other non ferroelectric oxides have been fabricated for use in phased array antennas. These composites have shown superior electronic properties and have been incorporated into several antenna designs. However, minimal testing has been accomplished to determine the electrical aging and fatigue caused by the large electric fields required to operate these devices. In this paper, a systematic study of the effect ... |
|
| Advanced Solid Lubricant Films by Ion-Beam Assisted Deposition |
28 NOV 94 |
12 pages |
| Authors:
Irwin L. Singer; Robert N. Bolster; Larry E. Seitzman; Kathryn J. Wahl; Marshall B. Peterson; NAVAL RESEARCH LAB WASHINGTON DC
|
| NRL is developing advanced solid lubricating films for bearing assemblies. The films are deposited by ion-beam assisted deposition (IBAD) to thickness that can be controlled from 0.02 micrometers (1 micron inch) to greater than or equal to 1 micrometer (40 microns inch). Unlike evaporated or sputter-deposited films, IBAD films are dense and adhere well to virtually all solid surfaces. Durable films have been deposited on bearing steels, Ti alloys and ... |
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| Method for Fabricating Vertical Bipolar Junction Transistors in Silicon Bonded to an Insulator. |
08 NOV 1994 |
|
| Authors:
Eric N. Cartagena; DEPARTMENT OF THE NAVY WASHINGTON DC
|
| A method is provided for manufacturing a bipolar transistor, comprising the steps of: (1) abutting a polished surface of a substantially single crystal silicon waler with a polished surface of an insulating substrate: (2) heating the abutting silicon water and insulating substrate at about 200 deg C. for about 30 minutes to form a bonded wafer having a silicon layer; (3) forming a silicon island from the silicon layer; (4) ... |
|
| Nanomaterials--A Membrane-Based Synthetic Approach |
NOV 94 |
38 pages |
| Authors:
Charles R. Martin; COLORADO STATE UNIV FORT COLLINS DEPT OF CHEMISTRY
|
| Nanomaterials constitute an emerging, interdisciplinary field of science that deals with the development of methods for preparing nanoscopic bits of a desired material (e.g. a polymer, metal, semiconductor) and with scientific investigations of the nanomaterials obtained. Nanomaterials have numerous possible commercial and technological applications. In addition, this field poses an important fundamental philosophical question--how do the properties of a nanoscopic bit of a material differ from the analogous properties for ... |
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| A Catalytic Method for the Conversion of Silanes to Stannanes |
08 OCT 94 |
10 pages |
| Authors:
Benjamin J. Warner; Sephen L. Buchwald; MASSACHUSETTS INST OF TECH CAMBRIDGE DEPT OF CHEMISTRY
|
| The transformation of alkynyl-, allyl-, and benzyltrimethylsilanes to the corresponding tributylstannanes is reported. The reaction is initiated by the addition of tetrabutylammonium fluoride to a mixture of the silane and bis(tributyltin)oxide in tetrahydrofuran. The stannanes are isolated in approx. quantitative yields after removal of the volatile bis(trimethylsilyl)oxide in vacuo. Silane, Stannane, Catalysis. |
|
| Characterization of Optical Polymers for Multi-Layered Electro-Optic Devices. |
OCT 1994 |
166 pages |
| Authors:
Lori E. Rohlev; COLORADO UNIV AT BOULDER DEPT OF ELECTRICAL AND COMPUTER ENGINEERING
|
| Nonlinear optical (NLO) polymers could potentially replace standard inorganic electrooptic materials, such as LiNb03 and GaAs, in integrated optoelectronic devices and systems. The large electrooptic coefficients and the low dielectric constants of poled polymers make them ideal for high-speed electrooptic applications. Electrooptic devices can be easily fabricated by spin coating the polymer onto a substrate, forming optical channels by bleaching and making material electrooptic by poling the channels. This simple ... |
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| Materials for High-Power Laser Applications: Point Defects in KTP and ZnGeP2 |
30 SEP 94 |
54 pages |
| Authors:
Larry E. Halliburton; WEST VIRGINIA UNIV MORGANTOWN DEPT OF PHYSICS
|
| The operation of devices utilizing nonlinear optical materials such as KTP and ZnGeP2 are limited at high laser power by point defects in the crystal. This project has used electron paramagnetic resonance (EPR) and electron nuclear double resonance (ENDOR) experimental techniques to identify and characterize the primary point defects in KTP, ZnGeP2, and CdGeAs2 crystals. In KTP, the primary electron trap (i.e., a Ti3+ ion) is associated with the formation ... |
|
| The Assessment of Fuel Cell Power Plants for Surface Combatants |
30 SEP 94 |
211 pages |
| Authors:
Ward Boughers; Philippe Goubalt; Marc Greenberg; Todd Heidenreich; Ray Kornbau; NAVAL SURFACE WARFARE CENTER CARDEROCK DIV BETHESDA MD
|
| This report describes the results of a study undertaken to determine the impact of fuel cell technology on the design and effectiveness of future naval surface combatants. The study involved the collection of data to characterize four different fuel cell technologies; proton exchange membrane, molten carbonate, phosphoric acid, and solid oxide fuel cells. This information was used to expand current computer models to develop specific fuel cell plants that met ... |
|
| Method for Laser-Assisted Silicon Etching Using Halocarbon Ambients. |
20 SEP 1994 |
|
| Authors:
Stephen D. Russell; Douglas A. Sexton; Richard J. Orazi; DEPARTMENT OF THE NAVY WASHINGTON DC
|
| An etching process allows a selective single-step patterning of silicon devices in a noncorrosive environment. The etching of silicon relies on a maskless laser-assisted technique in a gaseous halocarbon ambient, such as the gaseous chlorofluorocarbons, dichlorodifluoromethane and chloropentafluoroethane. Laser-assisted photothermal chemical etching reactions on silicon occur in these ambients when the incident fluence from an excimer laser at 248 nm exceeds the melt threshold (approximately 0.75 J/sq cm). When incident ... |
|
| Metastability in Molecules |
08 SEP 94 |
13 pages |
| Authors:
Rodney J. Bartlett; FLORIDA UNIV GAINESVILLE
|
| Synthesis and detonation of energetic materials involves several critical oxidation processes and associated intermediates. Carbonyl oxide, and its cyclic isomeric form, dioxirane, are two key compounds in such processes. Carbonyl oxide has never been observed experimentally, though it is one of the most discussed compounds awaiting detection. We performed high level coupled- cluster CCSD(T) calculations to characterize carbonyl oxide. These studies employed recently developed open-shell analytical gradients methods for CCSD(T), ... |
|
| Superplastic Ceramics |
01 SEP 94 |
10 pages |
| Authors:
Oleg D. Sherby; Woo-Jin Kim; STANFORD UNIV CA DEPT OF MATERIALS SCIENCE AND ENGINEERING
|
| Superplasticity is a newly observed phenomenon in ceramics, with the first publication appearing in 1986. The current program has centered on an experimental study of superplasticity in polycrystalline iron carbide. This material has been made superplastic by utilization of two processing methods: powder processing and ingot-processing. In both cases the end microstructure is a continuous phase of ultra-fine grained iron carbide. The ultra-fine grained powder processed material was successfully gas-pressure ... |
|
| Electrochemical Interfaces and Electrode Processes: Electrochemical Oxidation of Small Organisms |
01 SEP 94 |
24 pages |
| Authors:
Ernest B. Yeager; CASE WESTERN RESERVE UNIV CLEVELAND OH DEPT OF CHEMISTRY
|
| This report summarizes research involving mechanistic studies of the oxidation of small hydrocarbons and carbon monoxide on platinum in aqueous electrolytes, transition metal oxides as electrocatalysts for O2 reduction and as supports for dispersed platinum, and transition metal complexes exhibiting high catalytic activity for O2 reduction on graphite. This research has been pursued principally by graduate students, using the research for the Ph.D. dissertation. (Author) |
|
| The Surface Preparation of Aluminum Alloys Using the Phosphoric Acid Containment System for Repair |
SEP 1994 |
54 pages |
| Authors:
Susan S. Saliba; DAYTON UNIV OH RESEARCH INST
|
| The Phosphoric Acid Containment System (PACS) was developed by The Boeing Company and is intended to provide on-aircraft phosphoric acid anodization of aluminum surfaces. The first objective of this investigation was to determine if the PACS produces a surface equivalent to the phosphoric acid tank system. The second objective was to evaluate the PACS procedure against Air Force maintenance criteria and ascertain if operator sensitivity is an issue. In addition, ... |
|
| High Nitrogen Explosives. Part 1. 2,6-Dinitropyridines and Dibenzo-1,3a, 4,6a-Tetraazapentalenes |
SEP 94 |
85 pages |
| Authors:
Robin A. Nissan; William S. Wilson; Richard D. Gilardi; NAVAL AIR WARFARE CENTER WEAPONS DIV CHINA LAKE CA
|
| High nitrogen materials are sought as potential dense powerful but insensitive explosive and propellant ingredients. Progress towards the synthesis of 3,5-diamino-2,4,6-trinitropyridine-1-oxide is described. Also described is recent research to elucidate the chemistry of 2,4,8,10-tetranitrodibenzo-1,3a,4, 6a-tetraazapentalene (TACOT), which will enable the development of new energetic materials based on this ring system. Explosives, Synthesis, Sensitivity, Stability, Performance |
|
| Nitric Oxide-Mediated Antiplasmodial Activity in Human and Murine Hepatocytes Induced by Gamma Interferon and the Parasite Itself: Enhancement by Exogenous Tetrahydrobiopterin |
SEP 1994 |
5 pages |
| Authors:
Slyvie Mellouk; Sephen L. Hoffman; Zhi-Ze Liu; Patricia de la Vega; Timothy R. Billiar; NAVAL MEDICAL RESEARCH INST BETHESDA MD
|
| Expression of inducible nitric oxide (NO) synthase has been shown to inhibit the development of several pathogens, including fungi, bacteria, parasites, and viruses. However, there is still controversy as to whether this effector mechanism can inhibit the development of human pathogens. We now report that gamma interferon (IFN-gamma) induces the elimination of Plasmodium falciparum-infected primary human hepatocytes from cultures and that the antimalarial activity is dependent on NO. Infection with ... |
|
| High Performance YBCO Films |
25 AUG 94 |
13 pages |
| Authors:
Edgar J. Denlinger; Aly Fathy; David Kalokitis; Valerie Pendrick; Barry Thaler; DAVID SARNOFF RESEARCH CENTER PRINCETON NJ
|
| High quality YBCO films were successfully deposited on 2.5 cm by 2.5 cm magnesium fluoride substrates. Critical temperatures of 88-89K and transition widths of 0.5K were obtained. Surface quality of Sarnoff-polished magnesium fluoride was improved to a level that produced a Chi-min of about 17% using Rutherford Backscattering. The maximum STO dielectric layer thickness (for capacitor between ground plane and power plane layers) was found to be 2000 angstroms or ... |
|
| Aryl Gels and Related Materials. Synthesis and Characterization of a New Class of Microporous Materials |
16 AUG 94 |
17 pages |
| Authors:
Kenneth J. Shea; CALIFORNIA UNIV IRVINE
|
| The objective of this program is the synthesis and characterization of new families of optically responsive materials for use in optical device fabrication. The materials that have been developed are polysilsesquioxanes, hybrids of organic network polymers and inorganic oxides. The materials are prepared by sol-gel techniques employing molecular building blocks that contain a variable organic component and an inorganic oxide precursor. The resulting materials are molecular composites with no phase ... |
|
| Defect Reduction and Back Channel Degradation in SIMOX |
01 AUG 94 |
101 pages |
| Authors:
Fereydoon Namavar; SPIRE CORP BEDFORD MA
|
| Because of potential back channel leakage problems and parasitic bipolar effects in silicon-on-insulator (SOI) metal-oxide-semiconductor (MOS) devices, especially n-channel MOS devices which must operate in an ionizing radiation environment, it is desirable to produce SIMOX wafers which have a layer of poor quality silicon near the Si/buried SiO2 interface. Also, for device fabrication these wafers must have low defect, high quality silicon near the wafer surface. In this program we ... |
|
| Study of Improved Critical Currents and Mechanical Properties in the Y- Ba-Cu-O Superconductor with Silver or Y2BaCuO3 or 211 Dispersions |
AUG 94 |
93 pages |
| Authors:
Siu-Wai Chan; TRUSTEES OF COLUMBIA UNIV NEW YORK
|
| The microstructure of the top-seeded, single grain, melted textured YBCO materials with different vol% 211 were investigated. The homogeneity of 211 distribution was greatly improved by using a solution precipitated 211 powder in preparation. Crack spacings and twin spacings were found to decrease with increasing vol% of the 211 particles. The 211 particles were found to be effective in holding crack propagation. Relationship between twin spacing and interparticle spacing was ... |
|
| Characterization and Graphical Visualization of Fluxes of Oxides of Nitrogen from Agricultural Soils in North Carolina |
AUG 94 |
120 pages |
| Authors:
Benny D. Holbrook; NORTH CAROLINA STATE UNIV AT RALEIGH
|
| Oxides of nitrogen (NOx = NO + NO2) play a central role in tropospheric photochemistry. Natural biogenic emissions of NOx from soils are usually considered to be only a small fraction of the anthropogenic emissions, but the source strength is not well known. Field measurements of NOx were made in two seasons (summer and winter) in an agriculturally-managed field in North Carolina. The NO flux estimates were used to produce ... |
|
| Processing, Fabrication, Characterization and Device Demonstration of High Temperature Superconducting Ceramics |
30 JUL 94 |
27 pages |
| Authors:
Thomas S. Luhman; Ilhan A. Aksay; BOEING DEFENSE AND SPACE GROUP SEATTLE WA
|
| A detailed small-angle neutron scattering study of the vortex lattice in a single crystal of YBa2Cu307-x was made for a field of 0.5 tesla inclined at angles between 0 and 80 degrees to the crystalline c axis. The vortex lattice is triangular for all angles. For angles less than or equal to 70 degrees its orientation adjusts itself to maximize the pinning energy to densely and highly regularly spaced twin ... |
|
| Processing and Characterization of Mechanically Alloyed NiAl-Based Alloys |
20 JUL 94 |
85 pages |
| Authors:
Marek Dollar; Philip Nash; Stanislaw Dymek; Seung- Joon Hwang; Sung-Jae Suh; ILLINOIS INST OF TECH CHICAGO DEPT OF METALLURGICAL AND MATERIALS ENGINEERING
|
| Mechanical alloying of powders followed by hot extrusion has been used to produce NiAl-based materials. The technique is capable of producing fully dense, free of cracks, fine grained materials containing a bimodal distribution of aluminum oxide dispersoids. The mechanically alloyed materials produced in our laboratory are much stronger at both ambient and elevated temperatures and significantly more ductile than their cast counterparts. Minimum creep rates in the MA NiAl are ... |
|
| Novel Electrochemical Materials Prepared by Sol-Gel Chemistry |
15 JUL 94 |
12 pages |
| Authors:
Gregory C. Farrington; John O. Thomas; Stig Friberg; PENNSYLVANIA UNIV PHILADELPHIA DEPT OF MATERIALS SCIENCE AND ENGINEERING
|
| Description of project: This program is directed at preparing and characterizing novel gels, xerogels, and aerogels which, because of their conductivity and/or charge storage capability, have unusual electrochemical characteristics. Typical materials of interest are the transition-metal oxides currently being exploited in their polycrystalline forms in the electrodes of the lithium batteries. Characterization involves structural and electrochemical studies, atomic force microscopy, and novel X-ray diffraction and mu FTIR techniques. One of ... |
|
| Native-Oxide Defined Ring Contact for Low Threshold Vertical-Cavity Lasers |
04 JUL 1994 |
4 pages |
| Authors:
D. L. Huffaker; D. G. Deppe; K. Kumar; T. J. Rogers; TEXAS UNIV AT AUSTIN DEPT OF ELECTRICAL AND COMPUTER ENGINEERING
|
| Data are presented characterizing a new process for fabrication of vertical-cavity surface-emitting lasers based on the selective conversion of high Al composition epitaxial AlGaAs to a stable native oxide using wet oxidation. The native oxide is used to form a ring contact to the laser active region. The resulting laser active regions have dimensions of 8, 4, and 2 microns The lowest threshold laser is achieved with the 8-microns active ... |
|
| Chemically Modified Electrodes by Nucleophilic Substitution of Chlorosilylated Platinum Oxide Surfaces |
01 JUL 94 |
|
| Authors:
Chun-hsien Chen; James E. Hutchinson; Timothy A. Postlethwaite; John N. Richardson; R. W. Murray; NORTH CAROLINA UNIV AT CHAPEL HILL DEPT OF CHEMISTRY
|
| Chlorosilylated platinum oxide electrode surfaces can be generated by reaction of SiCl4 vapor with an electrochemically prepared monolayer of platinum oxide. A variety of nucleophilic agents (such as alcohols, amines, thiols, and Grignard reagents) can be used to displace chloride and thereby functionalize the metal surface. Electroactive surfaces prepared with ferrocene methanol as the nucleophile show that derivatization by small molecules can achieve coverages on the order of a full ... |
|
| Chemically Modified Electrodes by Nucleophilic Substitution of Chlorosilylated Platinum Oxide Surfaces |
01 JUL 94 |
|
| Authors:
Chun-hsien Chen; James H. Hutchison; Timothy A. Postlethwaite; John N. Richardson; R. W. Murray; NORTH CAROLINA UNIV AT CHAPEL HILL DEPT OF CHEMISTRY
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| Chlorosilylated platinum oxide electrode surfaces can be generated by reaction of SiCl4 vapor with an electrochemically prepared monolayer of platinum oxide. A variety of nucleophilic agents (such as alcohols, amines, thiols, and Grignard reagents) can be used to displace chloride and thereby functionalize the metal surface. Electroactive surfaces prepared with ferrocene methanol as the nucleophile show that derivatization by small molecules can achieve coverages on the order of a full ... |
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| Temperature Dependence of the Electromechanical Properties of O-3 PbTiO3-Polymer Piezoelectric Composite Materials |
JUL 1994 |
13 pages |
| Authors:
Kurt M. Rittenmyer; NAVAL RESEARCH LAB ORLANDO FL UNDERWATER SOUND REFERENCE DETACHMENT
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| The electromechanical properties of 0-3 ceramic-polymer composite piezoelectric materials manufactured by NTK Corporation in Japan have been measured as a function of temperature using several techniques. The elastic, dielectric, and piezoelectric constants were measured by fitting the complex admittance vs frequency spectrum to a model of a piezoelectric resonator near the electromechanical resonance. These properties are shown to vary significantly with temperature as a result of the glass-transition region of ... |
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| High Temperature Stability of Binary Microstructures Derived from Liquid Precursors |
30 JUN 94 |
99 pages |
| Authors:
Fred F. Lange; CALIFORNIA UNIV SANTA BARBARA COLL OF ENGINEERING
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| This program has emphasized two topics: (1) the crystallization of metastable, solid-solution structures, their partitioning into equilibrium structures and compositions, and the role of the metastable phase and its partitioning on forming unique, nanometer microstructures important to the mechanics of structural ceramics and their composites, and (2) the formation of single crystal thin films via spin coating single crystal substrates with solution precursors. Results for the first topic are now, ... |
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| Gradient Index Lenses from Sol-Gel Layering |
30 JUN 94 |
7 pages |
| Authors:
John D. Mackenzie; CALIFORNIA UNIV LOS ANGELES DEPT OF MATERIALS SCIENCE AND ENGINEERING
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| The research proposed here is based on the principle of the density gradient column. A liquid (A) of low density is continuously mixed into a liquid (B) of higher density while B is allowed to flow slowly down the wall of a glass cylinder. The feed rate of A is equal to the flow rate of mixture. Thus, a gradient density column is formed. Such columns have been used to ... |
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