12,852 Matching Results

Search Results

Advanced search parameters have been applied.
in subjects: "36 Materials Science"  
Results: 1 - 24 next
open access

Low-Cost Solar Array Project. Progress report 14, August 1979-December 1979 and proceedings of the 14th Project Integration Meeting

Description: Progress made by the Low-Cost Solar Array Project during the period August through November 1979, is described. Progress on project analysis and integration; technology development in silicon material, large-area sheet silicon, and encapsulation; production process and equipment development; engineering, and operations, and the steps taken to integrate these efforts are detailed. A report on the Project Integration Meeting held December 5-6, 1979, including copies of the visual materials used, … more
Date: January 1, 1980
Partner: UNT Libraries Government Documents Department
open access

Low cost Czochralski crystal growing technology: near term implementation of the flat plate photovoltaic cost reduction of the Low Cost Solar Array Project. Fifth quarterly progress report, April 1-June 30, 1980

Description: During this reporting period, the primary activity has been to develop microprocessor control of the crystal growth process and to develop and demonstrate the accelerated crystal growth program. Accelerated recharging of the quartz crucible by the RF melting of polycrystalline silicon feed rods was deemphasized by JPL primarily due to the unavailability of suitable quality feed rods at an effective economical price. The development of the cold crucible program as an alternative method of crucib… more
Date: January 1, 1980
Creator: Roberts, E. G.
Partner: UNT Libraries Government Documents Department
open access

Boron reclamation

Description: A process to recover high purity /sup 10/B enriched crystalline boron powder from a polymeric matrix was developed on a laboratory basis and ultimately scaled up to production capacity. The process is based on controlled pyrolysis of boron-filled scrap followed by an acid leach and dry sieving operation to return the powder to the required purity and particle size specifications. Typically, the recovery rate of the crystalline powder is in excess of 98.5 percent, and some of the remaining boron… more
Date: July 1, 1980
Creator: Smith, R. M.
Partner: UNT Libraries Government Documents Department
open access

Microcrystalline silicon growth for heterojunction solar cells. Second quarterly report, 1 April 1983-30 June 1983

Description: In this reporting period, a single source of evaporation with B mixed with highly doped Si was used instead of the co-evaporation of separate Si and B sources. The purpose was to reduce possible carbon contamination. The results of both the heterojunction or heteroface structures, however, were similar to last quarter when evaporation was used. The best Voc of the heterojunction was about 460mV and no improvement in Voc in the heteroface structure, was observed; slight Voc degradation occurred.… more
Date: January 1, 1983
Creator: Iles, P. A.; Leung, D. C. & Fang, P. H.
Partner: UNT Libraries Government Documents Department
open access

Institutional research and development, FY 1987

Description: The Institutional Research and Development program at Lawrence Livermore National Laboratory fosters exploratory work to advance science and technology, disciplinary research to develop innovative solutions to problems in various scientific fields, and long-term interdisciplinary research in support of defense and energy missions. This annual report describes research funded under this program for FY87. (DWL)
Date: January 1, 1987
Creator: Struble, G. L.; Lawler, G. M.; Crawford, R. B.; Kirvel, R. D.; Peck, T. M.; Prono, J. K. et al.
Partner: UNT Libraries Government Documents Department
open access

Electronic band structure and optical properties of the cubic, Sc, Y and La hydride systems

Description: Electronic band structure calculations are used to interpret the optical spectra of the cubic Sc, Y and La hydride systems. Self-consistent band calculations of ScH/sub 2/ and YH/sub 2/ were carried out. The respective joint densities of states are computed and compared to the dielectric functions determined from the optical measurements. Additional calculations were performed in which the Fermi level or band gap energies are rigidly shifted by a small energy increment. These calculations are t… more
Date: January 1, 1980
Creator: Peterman, D. J.
Partner: UNT Libraries Government Documents Department
open access

Vacuum ultraviolet electronic properties of liquids. Annual progress report, 1 November 1979-31 October 1980

Description: Areas covered are: optical and dielectric properties of hexamethyl-phosphoric triamide; photoemission from uv irradiated liquids; photon and photoelectron mean free paths in liquids; properties of Kapton films; and uv transmission of polycyclic organic molecules. (GHT)
Date: January 1, 1980
Creator: Painter, L.R.
Partner: UNT Libraries Government Documents Department
open access

Video monitoring system for enriched uranium casting furnaces

Description: A closed-circuit television (CCTV) system was developed to upgrade the remote-viewing capability on two oralloy (highly enriched uranium) casting furnaces in the Y-12 Plant. A silicon vidicon CCTV camera with a remotely controlled lens and infrared filtering was provided to yield a good-quality video presentation of the furnace crucible as the oralloy material is heated from 25 to 1300/sup 0/C. Existing tube-type CCTV monochrome monitors were replaced with solid-state monitors to increase the s… more
Date: March 1, 1978
Creator: Turner, P. C.
Partner: UNT Libraries Government Documents Department
open access

Stress corrosion cracking of uranium--niobium alloys

Description: The stress corrosion cracking behavior of U-2/sup 1///sub 4/, 4/sup 1///sub 2/, 6 and 8 wt % Nb alloys was evaluated in laboratory air and in aqueous Cl/sup -/ solutions. Thresholds for crack propagation were obtained in these environments. The data showed that Cl/sup -/ solutions are more deleterious than air environments. Tests were also conducted in pure gases to identify the species in the air responsible for cracking. These data showed the primary stress corrodent is water vapor for the mo… more
Date: March 1, 1978
Creator: Magnani, N.J.
Partner: UNT Libraries Government Documents Department
open access

High temperature ceramic membrane reactors for coal liquid upgrading

Description: In this project we intend to study a novel process concept, i.e, the use of ceramic membranes reactors in upgrading of coal derived liquids. Membrane reactors have been used in a number of catalytic reaction processes in order to overcome the limitations on conversion imposed by thermodynamic equilibrium. They have, furthermore, the inherent capability for combining reaction and separation in a single step. Thus they offer promise for improving and optimizing yield, selectivity and performance … more
Date: January 1, 1992
Creator: Tsotsis, T.T.
Partner: UNT Libraries Government Documents Department
open access

Exploring novel silicon-containing polymers---From preceramic polymers to conducting polymers with nonlinear optical properties

Description: Several new types of silicon-containing preceramic polymers, i.e., poly(diorganosilacetylene) and poly(diorganosilvinylene) have been synthesized with molecular weights from 10,000 to 120,000. These polymers could be thermally converted to SiC with a moderate to high char yields. Ready solubility and good processability made these types of polymers attractive in their applications to ceramics. The thermal polymerization of diethynyldiphenyl-silane, which was reported in 1968 to afford poly(diph… more
Date: October 7, 1991
Creator: Pang, Yi.
Partner: UNT Libraries Government Documents Department
open access

Joining of ceramics for high performance energy systems. Mid-term progress report, August 1, 1979-March 31, 1980

Description: The subject program is primarily an exploratory and demonstration study of the use of silicate glass-based adhesives for bonding silicon-base refractory ceramics (SiC, Si/sub 3/N/sub 4/). The projected application is 1250 to 2050/sup 0/F relaxing joint service in high-performance energy conversion systems. The five program tasks and their current status are as follows. Task 1 - Long-Term Joint Stability. Time-temperature-transformation studies of candidate glass adhesives, out to 2000 hours sim… more
Date: October 6, 1980
Creator: Smeltzer, C E & Metcalfe, A G
Partner: UNT Libraries Government Documents Department
open access

Cadmium sulfide/copper sulfide heterojunction cell research. Final report, February 26, 1979-July 15, 1980

Description: Extensive modifications were made to the multi-source deposition apparatus. These include the installation of a larger vacuum chamber on the existing system. The new chamber provides improved inter-source shielding, an improved substrate mounting and heating system, and a vacuum interlock for introducing substrates. CdS resistivity control by both In doping and off-stoichiometric deposition has been investigated. Indium doping has been achieved both by diffusion from a pre-deposited In layer an… more
Date: June 30, 1980
Creator: Thornton, J. A. & Cornog, D. G.
Partner: UNT Libraries Government Documents Department
open access

X-ray measurements of stresses and defects in EFG and large grained polycrystalline silicon ribbons. First quarterly report

Description: The first model of a modified Bond goniometer has been built and tested for the precision measurement of interplanar spacings in Si-single crystals. A change in interplanar spacing ..delta..d/d approximately = to +- 10/sup -5/ can be detected which corresponds to surface stresses of the order of +- 1000 psi. A second version of the goniometer is being assembled incorporating a removable microscope for precision alignment of the Si-strip into the primary X-ray beam.
Date: January 1, 1978
Creator: Wagner, C.N.J.
Partner: UNT Libraries Government Documents Department
open access

Repair Welding of Fusion Reactor Components

Description: Recent experimental investigations indicate that the repair welding of irradiated materials containing greater than 1 to 2.5 appm helium leads to catastrophic cracking in the heat affected zone of the weld. The high temperatures and cooling tensile stresses which occur during the welding process lead to enhanced helium bubble growth in the heat affected zone region, resulting in catastrophic cracking upon cooling. An investigation is proposed which seeks to determine the effect of stress state … more
Date: May 20, 1992
Creator: Chin, Bryan A.
Partner: UNT Libraries Government Documents Department
open access

Pacific Northwest Laboratory Report on Fusion Energy Research, April 1977 - June 1977

Description: The development of economic data for fusion power plants continued in a study estimating the potential impact of a shortage of materials important in fusion plant construction. In studies developing heat transfer and fluid flow design tools for fusion reactor blankets, preconceptual design studies were initiated to identify the potential design limits of water cooling in the first wall of Tokamak Next Step (TNS) concepts. In surface effects research clean gold samples were irradiated in the Uni… more
Date: July 1, 1977
Partner: UNT Libraries Government Documents Department
open access

The collaborative program of research in engineering sciences

Description: Research programs in the following areas are briefly described: High-Temperature Gas-Particle Reactions; Mathematical Modelling of Plasma Systems; Metal Transfer in Gas Metal-Arc Welding; Multivariable Control of Gas Metal-Arc Welding; Synthesis of Heat and Work Integration Systems for Chemical Process Plants; Parity Simulation of Dynamic Processes; Fundamentals of Elastic-Plastic Fracture: Three-Dimensional and Mechanistic Modelling; and Comminution of Energy Materials. Publications from each … more
Date: August 1, 1989
Creator: White, D.C.
Partner: UNT Libraries Government Documents Department
open access

Energy dependence of metallic-encapsulated thermoluminescent dosimeters. Annual report

Description: The gamma-ray energy responses of encapsulated /sup 7/LiF and CaF/sub 2/:Mn thermoluminescent dosimeters were measured and compred to calculated values. This study was performed in order to improve the accuracy of gamma-ray heating measurements made in polyenergetic gamma-ray fields such as Argonne National Laboratory's Zero Power Reactors. Equations used in the development of the TERC/III computer code and code input parameters are specified. A section on TLD precision is also included. Compar… more
Date: June 1980
Creator: Simons, G. G.
Partner: UNT Libraries Government Documents Department
open access

Analysis of fracture modes during extrusion and drawing of bimetal rods or wire. Analytical study of drawing and extrusion of superconducting filamentary wires: fracture problems and evaluation of temperature rise. Final report

Description: Based on the upper-bound theorem in limit analysis, a theoretical model describing sound flow, core fracture, and sleeve fracture in bimetal rods and wire during extrusion and drawing was developed. The variables affecting core and sleeve fracture are: reduction in area, die geometry, friction, relative size and strength of the core, and applied surface tractions. Within the wide range of combinations of these process variables, only a small range permits co-extrusion and codrawing without frac… more
Date: January 9, 1984
Creator: Avitzur, B.; Wu, R.; Chou, Y.T. & Talbert, S.
Partner: UNT Libraries Government Documents Department
open access

Coal Technology Program. Progress report for November 1977

Description: A block of Pittsburgh seam bituminous coal and a block of Wyodak subbituminous coal were pyrolyzed under reducing gas in support of in situ gasification. Information from previously completed block pyrolysis of bituminous coal under an argon atmosphere show that differences in evolved gas result from differences in heating rates. Compared to block pyrolysis at 0.3 C/sup 0//min, block pyrolysis at 3 C/sup 0//min produces less gas but gas with a higher heating value, yielding a higher overall pyr… more
Date: January 1, 1978
Partner: UNT Libraries Government Documents Department
open access

Investigation of joining techniques for advanced austenitic alloys

Description: Modified Alloys 316 and 800H, designed for high temperature service, have been developed at Oak Ridge National Laboratory. Assessment of the weldability of the advanced austenitic alloys has been conducted at the University of Tennessee. Four aspects of weldability of the advanced austenitic alloys were included in the investigation.
Date: May 1, 1991
Creator: Lundin, C. D.; Qiao, C. Y. P.; Kikuchi, Y.; Shi, C. & Gill, T. P. S.
Partner: UNT Libraries Government Documents Department
open access

(The relationship between microstructure and magnetic properties in high-energy permanent magnets characterized by polytwinned structures)

Description: This report summarizes the results of a study of the relationship between microstructure and magnetic properties in a unique genre of ferromagnetic material characterized by a polysynthetically twinned structure which arises during solid state transformation. These results stem from the work over a period of approximately 27 months of a nominal 3 year grant period. The report also contains a proposal to extend the research project for an additional 3 years. The polytwinned structures produce an… more
Date: January 1, 1992
Partner: UNT Libraries Government Documents Department
open access

LLL total flow geothermal program: summary of two-phase nozzle tests for scale control and materials performance

Description: A series of nozzle and wearblade tests to evaluate scale control and materials performance under total flow nozzle inlet conditions and simulated turbine blade environments was completed using Magmamax No. 1 well fluid. Brine acidification was effective in preventing scale in nozzles and on wearblade flow surfaces. Acid consumption measurements indicate that acid cost will be less than 2 mills/100 lb. brine. Measured erosion rates were low and the results indicate that available materials will … more
Date: December 1, 1977
Creator: Tardiff, G.E. (ed.)
Partner: UNT Libraries Government Documents Department
open access

Elastic and Plastic Strains and the Stress Corrosion Cracking of Austenitic Stainless Steels. Progress Report, April 30, 1977--December 30, 1977

Description: A newly developed test environment based on NaCl, Na/sub 2/SO/sub 4/, and HCl has provided some insight to several aspects of SCC in a transformable austenitic stainless steel. Current vs. time curves indicated the presence of the formation of a ''protective'' film which drastically reduced the anodic current leading to failure. This film, not indicated by the polarization curves, is subject to highly localized damage such as pitting. Thus, although it allows only very small corrosion currents,… more
Date: January 1, 1978
Creator: Troiano, A. R.
Partner: UNT Libraries Government Documents Department
Back to Top of Screen