| 3D Composite Grids for Flow Computations: the Grid Generation |
MAY 91 |
18 pages |
| Authors:
Ramana G. Venkata; Joseph Oliger; Joel Ferziger; STANFORD UNIV CA CENTER FOR LARGE SCALE SCIENTIFIC COMPUTATION
|
 | Flow situations involving localized phenomena and 3D, complex geometries are very important and are often encountered in engineering applications in the aerospace, chemical and petroleum industries. Such geometries defy attempts to lay a single grid over the entire domain, for numerical solution of the problem using finite-difference methods. In a Composite Grid method, the domain is decomposed into overlapping regions which communicate at their boundaries. Each of these is individually ... |
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| Effects of Multiple Filament Geometry in the Hot Filament Deposition of Diamond Films |
12 APR 91 |
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| Authors:
E. N. Farabaugh; A. Feldman; L. H. Robins; NATIONAL INST OF STANDARDS AND TECHNOLOGY GAITHERSBURG MD CERAMICS DIV
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 | Scaleup of hot filament chemical vapor deposition of diamond films requires knowledge of how filament geometry affects the deposition process. The effect of multiple filament geometry on the growth rate and surface morphology of diamond films is presented. Three factors were varied: the number of helical turns in a filament - 5, 10 or 15; the number of filaments present --1 or 2; and the CH4 fraction in the CH4-H2 ... |
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| Chemical Aspects of Pb-Zr-Ti Oxide Thin Film Synthesis by PE-MOCVD Below 500c, |
05 APR 1991 |
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| Authors:
William T. Petuskey; David A. Richardson; ARIZONA STATE UNIV TEMPE DEPT OF CHEMISTRY
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| The general features of the chemistry in synthesizing lead zirconium titanate thin films by PE-MOCVD are discussed based on a preliminary experimental investigation. A qualitative model was constructed as a guide for optimizing the formation of the perovskite phase in the as-deposited condition. This was based on concepts of crystal chemistry of the perovskite and pyrochlore structures and the observed deposition kinetics. Currently, thin films containing up to 92 vol ... |
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| PbTi03 Thin Films Grown by Organometallic Chemical Vapour Deposition, |
05 APR 1991 |
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| Authors:
G. J. M. Dormans; M. De Keijser; P. K. Larsen; PHILIPS RESEARCH LABS EINDHOVEN (NETHERLANDS)
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| We have used organometallic chemical vapour deposition (OMCVD) to deposit ferroelectric PbTiO3 films on both single crystalline (001)SrTiO3 and oxidized Si substrates provided with a platinum electrode, using the precursors titanium-iso-propoxide and tetra-ethyl lead. Epitaxial PbTiO3 layers were grown on (001)SrTiO3 at temperatures around 700 V. The epitaxial nature of the c-axis oriented PbTiO3 is confirmed by Rutherford backscattering spectrometry including channeling, x-ray diffraction (XRD) and high-resolution electron microscopy. A ... |
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| Bottom Electrodes for Integrated Pb(Zr,Ti)03 Films, |
05 APR 1991 |
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| Authors:
Phillip D. Hren; S. H. Rou; H. N. Al-Shareef; M. S. Ameen; NORTH CAROLINA STATE UNIV AT RALEIGH DEPT OF MATERIALS SCIENCE AND ENGINEERING
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| Lower electrodes for Pb(Zr,Ti)03 (PZT) used in ferroelectric random access memories must have good electrical conductivity and must interact as little as possible with the PZT film We have evaluated a number of bottom electrodes for use with PZT films deposited by ion beam sputter deposition These electrodes include Pt, PI/Ti, RuO2, ReO3, and CoSi2/Si3N4, all on SiO2/Si; and TiN and Pt on MgO. Films were studied by XTEM, Auger ... |
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| JPRS Report, Science & Technology USSR: Chemistry |
27 MAR 1991 |
|
| Authors:
JOINT PUBLICATIONS RESEARCH SERVICE ARLINGTON VA
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| The report contains information on national-level science policies, technology strategies, and research and development programs in USSR Science and Technology specially in Chemistry Research with particular attention to Environmental Chemistry, Laser materials, petroleum and coal processing and wood chemistry. |
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| Compatibilization of Blends of Crystallizable Polybutadiene Isomers by Precipitation and by Addition of Amorphous Diblock Copolymer |
15 FEB 91 |
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| Authors:
Moira M. Nir; Robert E. Cohen; MASSACHUSETTS INST OF TECH CAMBRIDGE DEPT OF CHEMICAL ENGINEERING
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| A brief summary of the research on compatibilized polymer blends is presented. Of particular significance is the model system of crystallizable polybutadiene isomers: trans 1,4 polybutadiene and syndiotactic 1,2 polybutadiene. Appropriate blending procedures, rapid precipitation from solvent (sometimes in the presence of an amorphous 1,4/1,2 polybutadiene block copolymer) led to a family of blends with attractive mechanical behavior. |
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| Alternative Training Agents Phase 1. Survey of Near-Term Candidate Fire Extinguishing Agents and Predicting Properties of Halocarbon Mixtures. Volume 1 |
FEB 91 |
|
| Authors:
Jonathan S. Nimitz; Robert E. Tapscott; Stephanie R. Skaggs; Harold D. Beeson; NEW MEXICO ENGINEERING RESEARCH INST ALBUQUERQUE
|
| IN this report, 14 compounds are examined as potential near-term candidates for alternative firefighter training agents for streaming applications. This list consists of suitable fluorine-containing compounds(primarily fluorocarbons, hydrofluorocarbons, and hydrochlorofluorocarbons) known to have had significant toxicity testing completed, with bulk production capabilities existing in the past, present, or anticipated near future. Many of these compounds are being produced or considered as replacements for chlorofluorocarbons (CFCs) in refrigeration and foam-blowing applications. ... |
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| Engineering and Design: Cathodic Protection System Using Ceramic Anodes |
05 JAN 1991 |
|
| Authors:
CORPS OF ENGINEERS WASHINGTON DC
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|
| A Study of the Gas Phase Chemistry of Solid Propellants Using a Microprobe Mass Spectrometer (MPMS) System: Preliminary Results for Solid Fuels (HTPB/Zecorez and BAMO/NMMO), Single-Base Propellant (M10) and an RDX-Based Propellant (BLX-9) |
91 |
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| Authors:
Thomas A. Litzinger; PENNSYLVANIA STATE UNIV UNIVERSITY PARK
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| Detailed knowledge of the gas-phase reactions which occur during propellant ignition and combustion are required to understand and model these processes. If detailed models were available, modification of propellant formulations for improved combustion behavior could be achieved with much less trial-and-error testing. Furthermore, detailed models could be used to generate simplified kinetics schemes for use in propellant models. The present research program, centers around the development and application of a ... |
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| The Ductility and Microstructure of Aluminum and Aluminum-Magnesium Alloys Deformed to Large Strains at Elevated Temperature |
91 |
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| Authors:
M. E. Kassner; G. A. Henshall; H. J. McQueen; OREGON STATE UNIV CORVALLIS DEPT OF MECHANICAL ENGINEERING
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| The ductility and microstructure of aluminum and aluminum-magnesium alloys deformed to large strains at elevated temperatures have been studied. Torsional ductility was measured at 110-601 C at strain rates 5.1 x 10-4 - 1.3 x 10-2/s. The ductility, at each strain rate, increases with increasing temperature to a "peak ductility" beyond which it decreases. Al-5.8 at % Mg was deformed to strains up to about 11 at 425 C (epsilon ... |
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| Carbothermal Synthesis of Silicon Nitride: Effect of Reaction Conditions |
91 |
|
| Authors:
S. J. P. Durham; K. Shanker; R. A. L. Drew; MCGILL UNIV MONTREAL (QUEBEC) DEPT OF METALLURGICAL ENGINEERING
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| Conditions for carbothermal synthesis of alpha-Si3N4 are presented with special emphasis on the reaction temperature, C:SiO2 ratio, and precursor mixing. With pure precursors, the conversion temperature is 1500 to 1550C. An excess of C is necessary for complete conversion, and a simple sol-gel-mixing technique provides excellent intermixing of the precursors. Copious flow of N2 gas throughout the reactor bed is essential if pure Si3N4 is to be produced; small concentrations ... |
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| Molten Salt Synthesis of a Complex Perovskite, Pb(Fe(0.5)Nb(0.5))O3 |
91 |
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| Authors:
C. C. Chiu; C. C. Li; S. B. Desu; VIRGINIA POLYTECHNIC INST AND STATE UNIV BLACKSBURG DEPT OF MATERIALS ENGINEE RING
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| Pure, single-phase stoichiometric Pb(Fe(0.5)Nb(0.5))O3 (PFN) powders were successfully formed by molten salt synthesis using mixtures of NaCl and KCl salts. Lower temperatures and shorter times (1/2 h at 800C) were needed for single phase PFN formation from molten salts relative to those required for solid-phase methods (4 h at 1000C). A systematic study indicating the effects of process parameters, such as temperature, time and amount of flux with respect to ... |
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| Formation of Lead Niobates in Molten Salt Systems |
91 |
|
| Authors:
C. C. Li; C. C. Chiu; S. B. Desu; VIRGINIA POLYTECHNIC INST AND STATE UNIV BLACKSBURG DEPT OF MATERIALS ENGINEE RING
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| The formation mechanisms, phase stability, impurity incorporation, and morphological characteristics of lead niobates obtained by molten salt synthesis were studied by X-ray diffraction analysis, scanning electron microscopy, and energy dispersive analysis. Results indicate that PbO is the fast-dissolving component of the constituent oxides and that the formation of lead niobates initiates at the surface of Nb2O5 powders. Reaction rates were faster in molten salts when compared to those of solid-state ... |
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| Silicon Nitride Powder Milling Kinetics in a High-Energy Agitation Ball Mill |
91 |
|
| Authors:
S. G. Malghan; D. B. Minor; L. S. H. Lum; NATIONAL INST OF STANDARDS AND TECHNOLOGY GAITHERSBURG MD CERAMICS DIV
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| The application of high energy agitation ball milling is described for silicon nitride powder size reduction in a specially designed system. All components of the milling system that come into contact with the powder are made of silicon nitride, and milling is carried out with hot-pressed silicon nitride media. The milling kinetics are examined by the measurement of particle size distribution and specific surface area of the milled powders as ... |
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| Nucleation and Growth of Diamond on Si, Cu and Au Substrates |
21 DEC 90 |
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| Authors:
C. M. Niu; G. Tsagaropoulos; J. Baglio; K. Dwight; A. Wold; BROWN UNIV PROVIDENCE RI DEPT OF CHEMISTRY
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| A hot tungsten filament reactor was used to deposit diamond films on silicon, copper and gold substrates. Diamond can be readily nucleated on all three substrates, but the nucleation density is greatly enhanced by prescratching with o.25 um diamond paste. Visual examination of photomicrographs of diamond crystallites formed on prescratched silicon substrates indicates that no new nuclei are formed between one and two hrs of deposition. However, new nuclei are ... |
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| Preparation and Characterization of Iron(III) Oxide Films by an Novel Spray Pyrolysis Method |
21 DEC 90 |
|
| Authors:
C. M. Niu; C. Hannigan; Y-t. Qian; S. Yang; K. Dwight; BROWN UNIV PROVIDENCE RI DEPT OF CHEMISTRY
|
| Alpha-Fe203 thin films were deposited on silicon substrates by nebulization of a 0.01 M solution of iron acetylacetonate in a 50% methanol/ water mixture followed by pyrolysis and annealing in flowing oxygen. The resulting films were characterized by x-ray diffraction, scanning electron microscopy, and their electrical transport behavior. The IR transmission spectrum of alpha-Fe203 recorded from such films agreed with published theoretical analysis based on the crystal structure. |
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| JPRS Report, Science & Technology, USSR: Chemistry |
30 NOV 1990 |
|
| Authors:
JOINT PUBLICATIONS RESEARCH SERVICE ARLINGTON VA
|
| The report contains foreign media information on issues related to analytical chemistry, Electrochemistry, Polymer Chemistry and Radiation Chemistry. |
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| Hyperfine and Superhyperfine Tensors as Probes of the Local Environment of Deep-Level Defect Centers |
15 OCT 90 |
|
| Authors:
Michael Cook; C. T. White; NAVAL RESEARCH LAB WASHINGTON DC
|
| In several recent theoretical studies, we have analyzed the local environment of deep-level defects through comparisons of theoretical and experimental hyperfine tensors. The principal hyperfine interactions sample the distribution of spin density near the center of defect site, and are diagnostics of the local bonding conformation; the smaller hyperfine (superhyperfine) tensors, which are used by couplings of the spin density with nuclei somewhat removed from the center of defect, give ... |
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| Experimental Studies of the Properties of Trihydrogen and Tetrahydrogen |
OCT 90 |
|
| Authors:
Aron Kuppermann; CALIFORNIA INST OF TECH PASADENA
|
| Results of theoretical calculations by Nicolaides et al. have suggested the existence of metastable tetrahydrogen (H4) molecules. The specific impulse of this species is estimated to be 1820 s, making it a very interesting candidate for a rocket propulsion system. The scattered products of the H3 + HI collisions are measured with the help of an electron bombardment quadrupole mass spectrometer, having two angular motion degrees of freedom. This complex ... |
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| Low Temperature Synthesis of High Purity Monoclinic Celsian Using Topaz. |
07 SEP 1990 |
|
| Authors:
Inna G. Talmy; Deborah A. Haught; DEPARTMENT OF THE NAVY WASHINGTON DC
|
| This invention relates to ceramics and more particularly to aluminosilicate ceramics. Ceramics based on monoclinic celsian (BaO-A12O3-2Si02) can be considered for applications requiring materials with a combination of high melting point, low thermal expansion, high thermal shock resistance, high-frequency working capabilities, low and thermally stable dielectric constant and low loss tangent. A process for preparing monoclinic celsian from topaz and BaCO3, powders by heating an intimate mixture of the powders ... |
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| Molecular Properties and Fate of Organic Chemicals |
14 AUG 90 |
|
| Authors:
Anders W. Andren; WISCONSIN UNIV-MADISON WATER CHEMISTRY PROGRAM
|
| The overall objectives for this project is to improve and evaluate present assessment procedures which are designed to predict the transport and fates including degradation pathways, of compounds of interest to the Air Force sphere. Specifically, our subobjectives may be summarized to: (1) Continue to update and improve aqueous solubility octanol-water partition coefficient, and vapor pressure predictive techniques as new property data appear in the literature. (2) Study the effect ... |
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| Installation, Operation and Maintenance for Reverse Osmosis Element Cleaning and Preservation System (ROECPS) |
31 JUL 1990 |
|
| Authors:
MARINE CORPS WASHINGTON DC
|
| Warnings and cautions appearing throughout this technical manual are of paramount importance to personnel and equipment safety. Prior to any attempt to operate, maintain, troubleshoot, or repair any part of the Reverse Osmosis Element Cleaning and Preservation System (ROECPS) or its support equipment, all warnings and cautions should be thoroughly reviewed and understood. Refer to the Safety Summary at the front of this manual for a complete list of warnings ... |
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| JPRS Report, Science & Technology, USSR: Chemistry |
12 JUN 1990 |
|
| Authors:
JOINT PUBLICATIONS RESEARCH SERVICE ARLINGTON VA
|
| The report contains a variety of abstracts on advanced technology and scientific research and development programs in USSR chemistry with particular attention to Chemical industry, inorganic chemistry and polymer science. |
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| Electrochemistry Using Nanometer-Sized Electrodes |
29 MAY 90 |
|
| Authors:
Reginald M. Penner; Michael J. Heben; Teresa L. Longin; Nathan S. Lewis; CALIFORNIA INST OF TECH PASADENA DEPT OF CHEMISTRY
|
| Electrodes with dimensions as small as 10 A have been fabricated and used for electrochemical studies. Remarkably large current densities are generated by these ultra small electrodes, as predicted by conventional radial diffusion theory. These large current densities have enabled the measurement of electron transfer rate constants, k sub het, which are two orders of magnitude faster than k sub het values accessible using any other electrochemical method. |
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| Coherence Scales of Wavefield during Propagation Through Naturally Disturbed Ionosphere in the Polar Cap, Auroral and Equatorial Regions, |
03 MAY 1990 |
|
| Authors:
S. Basu; Sunanda Basu; R. C. Livingston; GEOPHYSICS LAB (AFSC) HANSCOM AFB MA
|
| Phase and intensity scintillation measurements have been made at low latitudes in the equatorial anomaly region, and at high latitudes in the auroral oval and the polar cap regions, using phase coherent transmissions at 250 MHz from stationary and near stationary satellites. The observations pertain to periods of high solar activity when intense scintillation activity is recorded at each of the above observing sites. This data set has been utilized ... |
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| Synthesis of Qinghaosu Analogues as Potential Antiparasitic Agents. Phase 1 |
01 MAY 90 |
|
| Authors:
Duane J. Mazur; ELECTROSYNTHESIS CO INC BUFFALO NY
|
| The synthesis of a series of Qinghaosu analogues as potential anti- parasitic agents was studied. The key precursors to three intermediates were prepared and exposed to reaction with singlet oxygen. The expected ether endoperoxide functional group, essential to the activity of the parent structure, was obtained in one instance. This product, as well as another possible endoperoxide side product, was submitted to the USAMROC for in vitro biological evaluation. Characterization ... |
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| Development of Microencapsulation Techniques |
MAY 90 |
|
| Authors:
John D. Baldeschwieler; CALIFORNIA INST OF TECH PASADENA
|
| Surfactant vesicles are small, spherical shell-like structures composed of bilayers of surfactant molecules which can be used to contain an aqueous solution. Since a variety of materials can be encapsulated in such vesicles, they are ideal vehicles for many different applications. The advantages of vesicle formulations involve protection from the environment, sustained release, and targeted delivery of vesicle contents. Such potential for phospholipid vesicles as chemical delivery systems, and possibly ... |
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| Preparation of Ultra-Pure Metal Halides. |
27 MAR 1990 |
|
| Authors:
Paul E. Nordquist; Arnold H. Singer; DEPARTMENT OF THE NAVY WASHINGTON DC
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| Metal halides are ultrapurified by selective complexation with a complexing agent to form a charged first complex. A ligand forms an oppositely charged second complex with metallic impurities in the metal halide to be purified. A solution containing these complexes is then passed through an ion exchange column and the desired purified metal halide collected. The present method is particularly useful in the production of ultrapure metal halides, such as ... |
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| Nonlinear Optical Responses and Laser Damage Thresholds of Films of a Polarized Stilbene Side Chain Liquid Crystal Polymer and a Phthalocyanine |
15 MAR 90 |
|
| Authors:
Roger J. Reeves; Richard C. Powell; Marietta Bautista; Mingyand Zhao; Weiming Zhu; OKLAHOMA STATE UNIV STILLWATER DEPT OF CHEMISTRY
|
| Thin films of a side chain liquid crystal polymer (P-10) with a 4- dimethylaminostilbene-4'carboxylic ester mesogen were measured to have degenerate four wave mixing efficiencies at 532 nm 18 times that of carbon disulfide and 0.55 times that of a film of 1.5 weight percent 4-dimethylamino- 4'-nitrostilbene (DANS) in poly(methyl methacrylate) PMMA and second harmonic generation efficiency at 1064 nm 0.17 times that of a film of DANS in PMMA. ... |
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| Novel Approaches to the Synthesis of Fluorodinitromethane and Fluorodinitroethanol |
09 MAR 90 |
|
| Authors:
T. G. Archibald; N. Nguyen; J. S. Khosrowshahi; K. Baum; FLUOROCHEM INC AZUSA CA
|
| Fluorodinitroethanol (FDNE) is a basic building block for energetic plasticizers and binders. Without compromising thermal stability, FDNE provides greater energy content than dinitropropanol, which has been used in large quantities for manufacture of plasticizers. However, the current production cost limits use of FDNE to special applications, and there is a need for a new, low cost production method. Readily available, inexpensive FDNE and derivative compounds could be used to improve ... |
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| Determination of Sodium Cyanide in Copper and Cadmium Cyanide Plating Solutions by Precipitation-Formation Titration |
MAR 90 |
|
| Authors:
Samuel Sopok; ARMY ARMAMENT RESEARCH DEVELOPMENT AND ENGINEERING CENTER WATERVLIET NY BENET LABS
|
| The chemical literature lacks an acceptable analytical method to adequately determine and monitor sodium cyanide in copper and cadmium cyanide plating solutions in the plating processes. In this report, an improved method is presented providing acceptable analysis monitoring of this salt in these plating processes. The optimum operating ranges of sodium cyanide are 58 g/1 maximum in copper cyanide plating solutions and 149 g/1 maximum in cadmium cyanide plating solutions. ... |
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| Processing of Thermotropic Liquid Crystalline Polymers and Their Blends |
23 FEB 90 |
|
| Authors:
Wan-Chung Lee; Anthony T. Dibenedetto; Jack M. Gromek; CONNECTICUT UNIV STORRS LIQUID CRYSTALLINE POLYMER RESEARCH CENTER
|
| Preliminary studies were conducted on the hot-drawing of aromatic copolyester LCP fibers (KU-9211 and KU-9221 from Bayer A. G.) and blends of one of these with an aliphatic containing LCP (PET/PHB60 from Tennessee Eastman). The properties of the hot drawn fibers were characterized by measuring storage moduli, E, and molecular orientation parameters, , as a function of draw ration. A model was developed to correlate both (s) and 'E' with ... |
|
| Modified Maleic Anhydride Copolymers as E-Beam Resists |
15 FEB 90 |
|
| Authors:
S. Malhotra; B. C. Dems; Y. M. Namaste; F. Rodriquez; S. K. Obendorf; CORNELL UNIV ITHACA NY SCHOOL OF CHEMICAL ENGINEERING
|
| Copolymers of maleic anhydride with styrene, ethylene, and methyl vinyl ether were modified and evaluated for use as negative working resist materials in electron beam lithography. The copolymers used were modified by reaction with an organometallic compound, which resulted in incorporation of tin in the pendant chains of the copolymers. The polymers were blended with a reactive plasticizer, dipentaerythritol pentaacrylate (DPEPA), to enhance sensitivity and to improve resolution. Incorporation of ... |
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| Polymer Liquid Crystals with Side Chain Discogens |
05 FEB 90 |
|
| Authors:
Warren T. Ford; OKLAHOMA STATE UNIV STILLWATER DEPT OF CHEMISTRY
|
| With the long term goal of creating new polymers that have novel optical and electronic properties and can be fabricated as thin films, we have investigated three classes of liquid crystalline materials: discotic aza- macrocycles that may form complexes with metal ions with high selectivity, discotic phthalocyanines that may have strong nonlinear optical properties and are semiconductors, and polarized stilbenes that have strong second and third order nonlinear optical responses. ... |
|
| Ultramicroelectrode Ensembles. 5. Sealing Defects between the Ensemble Elements and the Host Membrane with Octadecyltrichlorosilane |
02 FEB 90 |
|
| Authors:
I. F. Cheng; Jane M. Schimpt; Charles R. Martin; TEXAS A AND M UNIV COLLEGE STATION DEPT OF CHEMISTRY
|
| We have recently developed a new procedure for preparing ensembles of ultramicroelectrodes. This procedure entails filling the pores of a microporous host membrane with a conductive material. Nuclepore filters, with linear, cylindrical pores, were used as the host membranes. We have used this approach to prepare ultramicroelectrode ensembles based on Platinum and carbon paste electrode elements. The Pt-based ensembles were prepared by electrochemically depositing the metal into the pores of ... |
|
| In-situ Differential Reflectance Study of the Etching of SiO2 Films |
18 JAN 90 |
|
| Authors:
Uean-Sin Pahk; S. Chongsawangvirod; E. A. Irene; NORTH CAROLINA UNIV AT CHAPEL HILL DEPT OF CHEMISTRY
|
| A differential reflectance technique has been applied to study the etching of Silicon dioxide films on Silicon substrates in-situ in the liquid Hydrogen Fluoride/Water environment as well as ex-situ. Essentially, the technique scans an incident optical beam in the spectral range of 200-800 nm across two adjacent samples at near normal incidence and the reflected beams are detected using lock-in amplification so as to measure only the difference in the ... |
|
| Gas Phase Decomposition of an Organometallic Chemical Vapor Decomposition Precursor to A1N: (Al(CH3)2NH2)3 |
15 JAN 90 |
|
| Authors:
Carmela C. Amato; John B. Hudson; Leonard V. Interrante; RENSSELAER POLYTECHNIC INST TROY N Y DEPT OF CHEMISTRY
|
| A novel technique for probing chemical vapor deposition reaction mechanisms is presented. A conventional hot-wall Pyrex reactor is coupled to a molecular beam apparatus. Preliminary results of the decomposition of an organmetallic precursor Aluminum Nitride, (Al(CH3)2NH2)3, indicate a decomposition temperature between 200 and 270 C. The mass spectrum of the precursor at 100 C provides evidence for the existence of a trimer-dimer equilibrium of the precursor at this temperature. Keywords: ... |
|
| A Study of the Gas Phase Chemistry of Solid Propellants Using a Microprobe Mass Spectrometer (MPMS) System: Initial Development of the MPMS system |
90 |
|
| Authors:
Thomas A. Litzinger; PENNSYLVANIA STATE UNIV UNIVERSITY PARK
|
| Detailed knowledge of the gas-phase reactions which occur during propellant ignition and combustion are required to understand and model these processes. If detailed models were available, modification of propellant formulations for improved combustion behavior could be achieved with much less trail-and-error testing. Furthermore, detailed models could be used to generate simplified kinetics schemes for use in propellant models. Without a firm basis for these simplified kinetic schemes, the kinetic parameters ... |
|
| Surface Effects in Sulphidation Reactions |
90 |
|
| Authors:
D. J. Young; J. P. Orchard; NEW SOUTH WALES UNIV KENSINGTON (AUSTRALIA)
|
| The kinetics of sulfidation of Fe and an FeNi alloy were studied by reacting with hydrogen sulfide-nitrogen atmosphere from 793 to 1073K; the kinetics of iron sulfidation were found to be intermediate in form to linear and parabolic rate laws; the instantaneous rate increased with hydrogen sulfide partial pressure for fixed equilibrium sulfur pressures and decreased as the equilibrium sulfur pressure increased for fixed hydrogen sulfur partial pressure; the FeNi ... |
|
| Oxidation and Sulphidation of Type 310S Stainless Steel at Elevated Temperatures |
90 |
|
| Authors:
J. S. Wolf; O. B. Cavin; CLEMSON UNIV SC DEPT OF MECHANICAL ENGINEERING
|
| Flat or bent sheet of aisi 310S stainless steel was exposed to air and SO2 at temperatures near 900c; exposure to air produced uniform deformation, while protective scales, composed of sesquioxide and spinal layers, were formed in both atmospheres; stress state, crystallinity and microstructure were all altered by the interaction of sulfur with the oxide scales; one approach in the development of alloys resistant to breakdown in sulfidizing atmospheres may ... |
|
| Synthesis of High Purity AlN by Nitridation of Li-Doped Al-Melt |
90 |
|
| Authors:
H. Scholz; P. Greil; TECHNISCHE UNIV HAMBURG (GERMANY F R)
|
| The isothermal nitridation of 2.3 wt% Li-doped Al-melt at 1273 K was investigated. Li promotes complete conversion of the Al to AlN and acts as a getter' reducing the oxygen impurities in the nitrogen atmosphere. Thus, high- purity AlN powder is obtained, containing low oxygen contamination (0.80 +/- 0. 02 wt%). |
|
| Feasibility of a Super High Energy Density Battery of the Li/BrF3 Electrochemical System |
15 DEC 89 |
|
| Authors:
Michael F. Pyszczek; Steven J. Ebel; Christine A. Frysz; WILSON GREATBATCH LTD CLARENCE NY
|
| The feasibility of developing a lithium/bromine trifluoride battery is being studied. Critical to this product development is materials selection. Consequently, efforts have been directed toward identifying candidate porous electrode separators, glasses for insulated electrical feed-throughs and metals for lid, case and current collector fabrication. Samples were evaluated via electrochemical testing techniques and one month storage in Teflon vials. Vial test results for metal samples did not vary significantly from those ... |
|
| Chemistry-Structure-Property Interrelationships for Calcareous Deposits as Stand-Alone Coatings |
07 DEC 89 |
|
| Authors:
William H. Hartt; Samual W. Smith; FLORIDA ATLANTIC UNIV BOCA RATON CENTER FOR MARINE MATERIALS
|
| Experiments have been performed where 1018, A710, A537 and HY80 steel specimens of surface finish corresponding to 120, 320, 600 and 1500 polishing were polarized potentiostatically in seawater at -900 mv (SCE). The resulting calcareous deposits were analyzed with regard to structure, composition and morphology and found to be comprised of a relatively thin inner Magnesium rich layer which formed initially and a subsequent, thicker, outer aragonite precipitate. The effect ... |
|
| Synthesis of Cubane Based Energetic Molecules |
DEC 89 |
|
| Authors:
Robert J. Schmitt; Jeffrey C. Botaro; Paul E. Penwell; SRI INTERNATIONAL MENLO PARK CA
|
| The need to pack more power with less weight into less space in tomorrow's weapons drives this program for the synthesis of new generations of super energetic materials based on cubane. Cubane's heat of formation (+161 kcal/mol), density (1.29 g/cm3), and strain energy (+159 kcal/mol) make a combination not exceeded by any other stable hydrocarbon available in reasonable quantities. The addition of energy-rich and/or oxidizing groups will create exceptionally dense ... |
|
| Dynamics of Electronically Excited Species in Gaseous and Condensed Phase |
DEC 89 |
|
| Authors:
P. K. Swaminathan; M. J. Redmon; C. S. Murthy; B. C. Garrett; G. A. Natanson; CHEMICAL DYNAMICS CORP UPPER MARLBORO MD
|
| In order to assess the potential of energetic molecules to be advanced rocket propellants, the Air Force High Energy Density Materials Program requires theoretical methods to predict the lifetimes of energetic molecules in condensed phase. This research met this need by developing novel dynamical methods which can be used to elucidate the microscopic dynamics controlling lifetimes relevant to energy storage in isolated and matrix-embedded molecules. This has resulted in the ... |
|
| Specification Development for a Viscoelastic Polymer Additive Based on Correlations between Performance Criteria and Material Characterization Tests |
DEC 89 |
23 pages |
| Authors:
Wendel J. Shuely; Seok H. Hong; Marie K. Potts; CHEMICAL RESEARCH DEVELOPMENT AND ENGINEERING CENTER ABERDEEN PROVING GROUND MD
|
| Based on an evaluation of the material properties that control fluid dynamic performance a number of conclusions, recommendations and technical plans can be advanced. For the QA/QC surveillance of a viscoelastic polymer additive, a variety of material property test methods were planned. The correlation between the results of these tests and the performance criteria was outlined. A general scheme of the usage of the results of the tests and their ... |
|
| Quantitative Determination of 1, 2-Ethanediol Contamination in Used Diesel Lubricating Oils by Gas Chromatography/Mass Spectrometry |
DEC 89 |
|
| Authors:
John A. Hiltz; John J. Power; DEFENCE RESEARCH ESTABLISHMENT ATLANTIC DARTMOUTH (NOVA SCOTIA)
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| A quantitative method for the determination of 1,2-ethanediol (ethylene glycol) in used diesel lubricating oils is described. The method involves derivatization of the glycol with a proprietary silylating reagent, TRISYL(TM)Z, to improve the chromatography of the glycol on a non-polar capillary column. Separation, detection and quantitative analysis of the trimethylsilyl derivative of the glycol, namely, 2,2,7,7-tetramethyl-3,6-dioxa- 2,7-disilaoctane, was carried out using capillary gas chromatography/mass spectrometry. The response of the trimethylsilyl ... |
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| Aid-Financed Procurement: Allegations of Irregularities in the Procurement of an Oil Drilling Chemical |
DEC 89 |
21 pages |
| Authors:
GENERAL ACCOUNTING OFFICE WASHINGTON DC NATIONAL SECURITY AND INTERNATIONAL A FFAIRS DIV
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| The General Accounting Office's review included research on the production and uses of CMC, specifications established by Oil Companies Materials Association, and standards identified by the oil-drilling industry. Analyzed were statistics on annual CMC production and import/export levels. GAO met with AID'S procurement officials and obtained information on its commodity import program. AID's regulations on its source and origin requirements were also reviewed. GAO obtained and reviewed pertinent documents, such ... |
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| Colloid and Interface Chemistry Aspects of Ceramics |
29 NOV 89 |
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| Authors:
Egon Matijevic; CLARKSON UNIV POTSDAM NY DIV OF RESEARCH
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| This comprehensive, long term, interdisciplinary program has a dual |
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Industrial Chemistry and Chemical Processing
