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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 433 records · Page 24
All sourcesNASA NTRSDOE OSTI
NASA NTRS1980

Advanced resin systems for graphite epoxy composites

The value of resin/carbon fiber composites as lightweight structures for aircraft and other vehicle applications is dependent on many properties: environmental stability, strength, toughness, resistance to burning, smoke produced when burning, raw material costs, and complexity of processing. A number of woven carbon fiber and epoxy resin composites were made. The epoxy resin was commercially available tetraglycidylmethylene dianiline. In addition, composites were made using epoxy resin modified with amine and carboxyl terminated butadiene acrylonitrile copolymer. Strength and toughness in flexure as well as oxygen index flammability and NBS smoke chamber tests of the composites are reported.

Gilwee, W. J.↗
NASA NTRS1980

Chemicals from biomass - The U.S. prospects for the turn of the century

Historically, chemicals from biomass have been and are expected to be economical in three major areas: byproducts, specialty items and polymers. Assessments of producing major chemicals from biomass in a processing plant based on the available conversion techniques indicate that they are not economically attractive, with the possible exception of conversion to ammonia and ethanol. The deterrents are the heavy capital investments, dependability of raw material supply and transportation costs for large plants, lack of operation experience, inadaptability of market variations, and competition from petroleum and coal. More importantly, it is also shown that even if chemicals from biomass were economical today, the resultant savings in petroleum would be far less than those achieved through other options available for the utilization of biomass as fuel and structural material. Thus, it is concluded that near-term research and development must be toward improved conversion processes, recovery of valuable products from waste streams at existing plants, more efficient use of biomass of energy and more efficient production of superior material products.

Sarbolouki, M. N.↗
NASA NTRS1982

Bipulsating Technique for Silicon Production

Method controls reaction temperature and rate of reaction of sodium and silicon tetrafluoride by alternately adding measured amounts of reactants. Technique used in large reactor, where heat dissipation becomes serious problem, to control reactor temperatures. Highly efficient method, which would utilize almost 100 percent of raw materials.

Sanjurjo, A.↗
NASA NTRS1983

Electroforming for High-Performance Products

Report describes development of processes and procedures for preparation of specifications for electroforming nickel and copper outer shells on cooled rocket thrust-chamber liners. Specifications represent merging of technical contributions from many sources into guide for producers of electroformed, high-performance products. Raw materials, conducting solutions and deposition rates are evaluated.

Malone, G. A.↗
NASA NTRS1981

Insects: A nutritional alternative

Insects are considered as potential food sources in space. Types of insects consumed are discussed. Hazards of insect ingestion are considered. Insect reproduction, requirements, and raw materials conversion are discussed. Nutrition properties and composition of insects are considered. Preparation of insects as human food is discussed.

Dufour, P. A.↗
NASA NTRS1981

An hierarchical system architecture for automated design, fabrication, and repair

The architecture of an automated system which has the following properties is described: (1) if it is presented with a final product specification (within its capabilities) it will do the detailed design (all the way down to the raw materials if need be) and then produce that product; (2) if a faulty final product is presented to the system, it will repair it. Interesting extensions of this architecture would be the ability to add fabricator nodes when required and the ability to add entire ranks when required. This sort of system would be a useful component of a self-replicating system (used in space exploration).

Cliff, R. A.↗
NASA NTRS1983

Fabricating Slotted-Waveguide Arrays From Sheet Metal

Low-cost lightweight waveguides formed from rolls of aluminum. Array formed from sheared, punched, and bent aluminum sheets. Sheets alined with punched jig holes and joined by laser-beam or resistance spot welding. Process permits use of thin metal to reduce raw material costs and mass. Also holds closer tolerances than usually attained in sheet-metal work.

Brown, W. C.↗
NASA NTRS1982

Development of an all-metal thick film cost effective metallization system for solar cells

Electrodes made with pastes produced under the previous contract were analyzed and compared with raw materials. A needle-like structure observed on the electroded solar cell was identified as eutectic copper-silicon, a phase considered to benefit the electrical and metallurgical properties of the contact. Electrodes made from copper fluorocarbon and copper silver fluoride also contained this phase but had poor adhesion. A liquid medium, intended to provide transport during carbon fluoride decomposition was incorporated into the paste resulting in better adhesion. The product survived preliminary environmental tests. A 2 cm by 2 cm solar cell made with fluorocarbon activated copper electrodes and gave 7% AMI efficiency (without AR coating). Both silver fluoride and fluorocarbon screened paste electrodes can be produced for approximately $0.04 per watt.

Ross, B.↗
NASA NTRS1982

Plasma-sprayed self-lubricating coatings

One of the most important criterion for acceptable commercial application of a multiple phase composition is uniformity and reproducibility. This means that the performance characteristics of the coat - e.g., its lubricating properties, bond strength to the substrate, and thermal properties - can be readily predicted to give a desired performance. The improvement of uniformity and reproducibility of the coats, the oxidation behavior at three temperature ranges, the effect of bond coat and the effect of preheat treatment as measured by adhesive strength tests, coating examination procedures, and physical property measurements were studied. The following modifications improved the uniformity and reproducibility: (1) changes and closer control in the particle size range of the raw materials used, (2) increasing the binder content from 3.2% to 4.1% (dried weight), and (3) analytical processing procedures using step by step checking to assure consistency.

Nakamura, H. H.↗
NASA NTRS1981

Fuel quality-processing study. Volume 2: Literature survey

The validity of initial assumptions about raw materials choices and relevant upgrading processing options was confirmed. The literature survey also served to define the on-site (at the turbine location) options for fuel treatment and exhaust gas treatment. The literature survey also contains a substantial compilation of specification and physical property information about liquid fuel products relevant to industrial gas turbines.

Jones, G. E., Jr.↗
NASA NTRS1982

Single crystal growth of upgraded metallurgical silicon by HEM for photovoltaic applications

Commercially available metallurgical grade (MG) silicon has high B and P content which is not reduced significantly by directional solidification. By choosing high purity raw materials for an experimental Submerged Electrode Arc Furnace, most of the impurities are reduced to 10 ppmw. Directional solidification of upgraded metallurgical grade (UMG) silicon by the Heat Exchanger Method (HEM) has produced 16 cm x 16 cm cross section ingots with nearly single crystal structure. The main problem encountered during directional solidification was SiC impurities dispersed through the structure. Solar cells fabricated from UMG silicon that was directionally solidified twice by HEM have shown up to 12.33% (am1) conversion efficiency.

Khattak, C. P.↗
NASA NTRS1982

The lunar regolith - Chemistry, mineralogy, and petrology

The data base on the lunar regolith is surveyed to form a synthesis of the lunar regolith chemistry, mineralogy, and petrology. The data were derived from samples collected by the Apollo missions 11-17 and the Luna 16, 20, and 24 probes. The missions were sent to sample formations and areas which typified the common observed features of the lunar surface. Drive tubes were used to extract samples from beneath the surface in order to study the relationship between the regolith and the bedrock, as well as to identify the processes that formed the regolith, which is regarded as the prime source of raw materials for early lunar industrial activities. Regolith origins are now understood to be destructive processes of comminution and constructional processes of agglutinate formation. Mixing occurs on the local scale, although lateral transport is inefficient on the moon. The usual contents of the fraction of regolith less than 10 microns in diameter are Al2O3, CaO, Na2O, K2O, light REE, and Th.

Papike, J. J.↗
NASA NTRS1983

Sintering, properties and fabrication of Si3N4 + Y2O3 based ceramics

Pure silicon nitride shows a remarkable resistance to sintering without the use of densification additives. The present investigation is concerned with results which show the effect of chemical content on sinterability, taking into account the composition, raw material impurities, and processing contaminants. Aspects of sintering are discussed along with strength characteristics, and oxidation relations. Attention is given to phase field I and II materials, phase field III and IV materials, tungsten carbide and oxidation at 600 C, and studies involving shape fabrication by injection molding. It was found that in sintering Si3N4 + Y2O3 an increase in the amount of Y2O3 and, in particular, the addition of Al2O3 enhances the fluidity of the liquid phase.

Quackenbush, C. L.↗
NASA NTRS1985

Automated Solar-Panel Fabricator

Automated computer-controlled system based on standard commercial industrial robot takes solar cells and other raw materials and assembles them into completed solar panels.

Hagerty, J. J.↗
NASA NTRS1983

Study and review of permanent magnets for electric vehicle propulsion motors

A study of permanent magnets (PM) was performed in support of the DOE/NASA electric and hybrid vehicle program. PM requirements for electric propulsion motors are analyzed, design principles and relevant properties of magnets are discussed. Available PM types are reviewed. For the needed high-grade magnets, design data, commercial varieties and sources are tabulated, based on a survey of vendors. Economic factors such as raw material availability, production capability and cost are analyzed, especially for cobalt and the rare earths. Extruded Mn-Al-C magnets from Japan were experimentally characterized. Dynamic magnetic data for the range -50 deg to +150 deg C and some mechanical properties are reported. The state of development of the important PM material families is reviewed. Feasible improvements or new developments of magnets for electric vehicle motors are identified.

Strnat, K. J.↗
NASA NTRS1984

The role of water in slip casting

Slips and casting are considered in terms of physical and colloidal chemistry. Casting slips are polydisperse suspensions of lyophobic particles in water, whose degree of coagulation is controlled by interaction of flocculating and deflocculating agents. Slip casting rate and viscosity are functions of temperature. Slip rheology and response to deflocculating agents varies significantly as the kinds and amounts of colloid modifiers change. Water is considered as a raw material. Various concepts of water/clay interactions and structures are discussed. Casting is a de-watering operation in which water moves from slip to cast to mold in response to a potential energy termed moisture stress. Drying is an evaporative process from a free water surface.

Mccauley, R. A.↗
NASA NTRS1985

Purifying Aluminum by Vacuum Distillation

Proposed method for purifying aluminum employs one-step vacuum distillation. Raw material for process impure aluminum produced in electrolysis of aluminum ore. Impure metal melted in vacuum. Since aluminum has much higher vapor pressure than other constituents, boils off and condenses on nearby cold surfaces in proportions much greater than those of other constituents.

Du Fresne, E. R.↗
NASA NTRS1985

Electrolysis of simulated lunar melts

Electrolysis of molten lunar soil or rock is examined as an attractive means of wresting useful raw materials from lunar rocks. It requires only hat to melt the soil or rock and electricity to electrolyze it, and both can be developed from solar power. The conductivities of the simple silicate diopside, Mg CaSi2O6 were measured. Iron oxide was added to determine the effect on conductivity. The iron brought about substantial electronic conduction. The conductivities of simulated lunar lavas were measured. The simulated basalt had an AC conductivity nearly a fctor of two higher than that of diopside, reflecting the basalt's slightly higher total concentration of the 2+ ions Ca, Mg, and Fe that are the dominant charge carriers. Electrolysis was shown to be about 30% efficient for the basalt composition.

Lewis, R. H.↗