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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 1,189 records · Page 66
All sourcesNASA NTRSDOE OSTI
DOE OSTI2026

Tunable Conversion of Poly(Acrylic Acid) to Vinyl Methyl Ether Copolymers via Electrochemical Decarboxylation

Recognizing the potential of polymer-to-polymer transformations for plastics valorization, a new electrochemical strategy for the decarboxylative functionalization of polyacrylates has been developed. In contrast to most electrochemical approaches to plastic waste valorization that use small-molecule mediators or only form deconstruction products, this report describes one of the first direct electrochemical redox upconversions of a commodity polymer and involves activation of poly(acrylic acid), a material commonly found in disposable diapers and other personal hygiene products. Via electrochemical decarboxylation, poly(acrylic acid) is converted to methyl ether-containing copolymers. Although methods to prepare the 1:1 regularly alternating poly(vinyl methyl ether-alt-maleic anhydride) are known, routes to generate copolymers with variable levels of vinyl methyl ether and acrylate moieties are unknown, but such polymers may have utility in similar applications, such as dentifrices. Tunable conversions with up to 62 mol% vinyl methyl ether content were achieved via controlled-current electrolyses at >100 mA. This approach enables efficient access to copolymers with broad range of comonomer content from a common waste polymer starting material.

Dauzvardis, Fabian [University of Delaware, Newark↗
DOE OSTI2025

3D pattern formation of a protein–membrane suspension

Many essential cellular processes, including cell division and the establishment of cell polarity during embryogenesis, are regulated by pattern-forming proteins. These proteins often need to bind to a substrate, such as the cell membrane, onto which they interact and form two-dimensional (2D) patterns. It is unclear how the membrane’s continuity and dimensionality impact pattern formation. Here, we address this gap using the MinDE system, a prototypical example of pattern-forming membrane proteins. We show that when the lipid substrate is fragmented into submicrometer-sized diffusive liposomes, adenosine triphosphate-driven protein–protein interactions generate three-dimensional (3D) spatially extended patterns, despite the complete loss of membrane continuity. Remarkably, these 3D patterns emerge at scales four orders of magnitude larger than the individual liposomes. By systematically varying protein concentration, liposome size, and density, we observed and characterized a variety of 3D dynamical patterns not seen on continuous 2D membranes, including traveling waves, dynamical spirals, and a coexistence phase. Simulations and linear stability analysis of a coarse-grained model revealed that the physical properties of the dispersed membrane effectively rescale both the protein–membrane binding rates and diffusion, two key parameters governing pattern formation and wavelength selection. These findings highlight the robustness of Min’s pattern-forming ability, suggesting that protein–membrane suspensions could serve as an adaptable template for studying out-of-equilibrium self-organization in 3D, beyond in vivo contexts.

36 MATERIALS SCIENCE↗
NASA NTRS1971

Sensing land pollution.

Land pollution is described in numerous ways by various societies. Pollutants of land are material by-products of human activity and range from environmentally ineffective to positively toxic. The pollution of land by man is centuries old and correlates directly with economy, technology and population. In order to remotely sense land pollution, standards or thresholds must be established. Examples of the potential for sensing land pollution and quality are presented. The technological capabilities for remotely sensed land quality is far advanced over the judgment on how to use the sensed data. Until authoritative and directive decisions on land pollution policy are made, sensing of pollutants will be a random, local and academic affair.

Bowden, L. W.↗
NASA NTRS1972

Apollo 14 mission report.

The formal training for the crew was conducted over a time span of 20 months. The levels of vibration and oscillation, reported by earlier crews, were essentially unchanged during the launch of Apollo 14. A total of five attempts were required before docking was successfully achieved. Navigation was the most difficult problem encountered during lunar surface activities. A loose gray mantle of material covered the entire surface to an undetermined depth. Solar wind and magnetic field measurements were conducted during the time on the lunar surface.

Shepard, A. B., Jr.↗
NASA NTRS1972

The evolution of water vapor in the atmosphere of Venus.

Examination of the feasibility of loss of water vapor from the Venus atmosphere, assuming H2O as the sole initial constituent. A steady-state model is constructed, and the photochemistry establishes the distribution of important products in the upper atmosphere. Calculations of exospheric temperatures yield values as high as 100,000 K. Such large temperatures result from the large abundance of atomic hydrogen in the exosphere, and imply a dynamic outflow of all constituents from the upper region of the atmosphere. Such an outflow would cause the escape of all hydrogen and some of the oxygen resulting from dissociation of H2O. Little loss of CO2 would result, due to its low abundance in the upper region, permitting its accumulation to the present observed value. It is concluded that if Venus formed from the same mix of materials as the earth, much tectonic activity and fairly rapid outgassing must have occurred during the early phase of its history to account for the loss of water vapor.

Smith, L. L.↗
NASA NTRS1973

Friction and wear behavior of glasses and ceramics

Adhesion, friction, and wear behavior of glasses and ionic solids are reviewed. These materials are shown to behave in a manner similar to other solids with respect to adhesion. Their friction characteristics are shown to be sensitive to environmental constituents and surface films. This sensitivity can be related to a reduction in adhesive bonding and the changes in surficial mechanical behavior associated with Rehbinder and Joffe effects. Both friction and wear properties of ionic crystalline solids are highly anisotropic. With metals in contact with ionic solids the fracture strength of the ionic solid and the shear strength in the metal and those properties that determine these will dictate which of the materials undergoes adhesive wear. The chemical activity of the metal plays an important role in the nature and strength of the adhesive interfacial bond that develops between the metal and a glass or ionic solid.

Buckley, D. H.↗
NASA NTRS1972

Applications of activation analysis to geochemical, meteoritic and lunar studies.

The application of activation analysis techniques to the analysis of cosmological materials, i.e., terrestrial, tektitic, meteoritic, and lunar matter, is reviewed. Elemental determinations can be made by instrumental fast-neutron and thermal-neutron activation analysis, photonuclear and charged-particle activation analysis, and by radiochemical neutron activation analysis. Partition-coefficient methods, autoradiography studies, gamma-gamma coincidence counting, and age determination by neutron activation are discussed. Attention is given to K-Ar and I-Xe dating of meteorites.

Showalter, D. L.↗
NASA NTRS1974

Skylab contributions to the future

Skylab showed that a multidisciplinary manned space station is practical and can be highly productive. Quality data was produced concerning earth resources (mineral resources, agriculture, climatology, etc.), solar astronomy (solar activity, magnetic fields, and solar winds), materials sciences (e.g., zero-gravity crystal growth), and astronomy and astrophysics (including observations of comet Kohoutek). Two types of astronaut maneuvering unit were tested. Medical data are applicable to adaptational environmental physiology.

Schneider, W. C.↗
NASA NTRS1978

Fluxless Brazing and Heat Treatment of a Plate-Fin Sandwich Actively Cooled Panel

The processes and techniques used to fabricate plate-fin sandwich actively cooled panels are presented. The materials were 6061 aluminum alloy and brazing sheet having clad brazing alloy. The panels consisted of small scale specimens, fatigue specimens, and a large 0.61 m by 1.22 m test panel. All panels were fluxless brazed in retorts in heated platen presses while exerting external pressure to assure intimate contact of details. Distortion and damage normally associated with that heat treatment were minimized by heat treating without fixtures and solution quenching in an organic polymer solution. The test panel is the largest fluxless brazed and heat treated panel of its configuration known to exist.

Beuyukian, C. S.↗
NASA NTRS1980

Overview of a stirling engine test project

Tests were conducted on three Stirling engines ranging in size from 1.33 to 53 horsepower (1 to 40 kW). The tests were directed toward developing alternative, backup component concepts to improve engine efficiency and performance or to reduce costs. Some of the activities included investigating attractive concepts and materials for cooler-regenerator units, installing a jet impingement device on a Stirling engine to determine its potential for improved engine performance, and presenting performance maps for initial characterization of Stirling engines. The experiment results of the tests are presented along with predictions of results of future tests to be conducted on the Stirling engines.

Slaby, J. G.↗
NASA NTRS1980

Mass ejections

Observations and model simulations of solar mass ejection phenomena are examined in an investigation of flare processes. Consideration is given to Skylab and other observations of flare-associated sprays, eruptive prominences, surges and coronal transients, and to MHD, gas dynamic and magnetic loop models developed to account for them. Magnetic forces are found to confine spray material, which originates in preexisting active-region filaments, within steadily expanding loops, while surges follow unmoving, preexisting magnetic field lines. Simulations of effects of a sudden pressure pulse at the bottom of the corona are found to exhibit many characteristics of coronal transients associated with flares, and impulsive heating low in the chromosphere is found to be able to account for surges. The importance of the magnetic field as the ultimate source of energy which drives eruptive phenomena as well as flares is pointed out.

Rust, D. M.↗
NASA NTRS1981

Ion beam microtexturing of surfaces

Some recent work in surface microtecturing by ion beam sputtering is described. The texturing is accomplished by deposition of an impurity onto a substrate while simultaneously bombarding it with an ion beam. A summary of the theory regarding surface diffusion of impurities and the initiation of cone formation is provided. A detailed experimental study of the time-development of individual sputter cones is described. A quasi-liquid coating was observed that apparently reduces the sputter rate of the body of a cone compared to the bulk material. Experimental measurements of surface diffusion activation energies are presented for a variety of substrate-seed combinations and range from about 0.3 eV to 1.2 eV. Observations of apparent crystal structure in sputter cones are discussed. Measurements of the critical temperature for cone formation are also given along with a correlation of critical temperature with substrate sputter rate.

Robinson, R. S.↗
NASA NTRS1983

Space Transportation System Mission STS-7

The second flight of Challenger was another exceptional flight in that 11 major objectives were accomplished. The TELESAT-F and PALAPA-B1 were deployed exactly on time. The SPAS-01 attached and detached operations went extremely well despite some heating problems with the SPAS. The OSTA-2 experiments for the Material Experiments Assembly and Material Wissenschaftliche Autone Unter Schwerelosigkeit were activated as planned with no indications of anomalies, and the MLR and CFES experiment packages in the middeck area were operated by the crew as planned. Ninety-six percent (56 of 58) of the assigned flight test objectives were completed. The turnaround time was accomplished in the least time to date (only 99.5 hours) and the return to KSC was completed with a total of only 5 days loss of program time.

Source record↗
NASA NTRS1984

Space-exposed experiment developed for students

This experiment will offer students the opportunity to evaluate the survivability of seeds stored in the space environment and to determine possible mutants and changes in the mutation rate which may occur. The objectives of this experiment are to involve a very large number of students in a national project to generate interest in science and related disciplines; to offer students from the elementary through the university level an opportunity to participate in a first-hand experiment with materials flown in space; to permit active involvement in classroom experiment design, decision making, data gathering, and comparison of results; and to emphasize a multidisciplinary approach to the project involving subject areas other than science.

Grigsby, D. K.↗
NASA NTRS1988

Dynamic shear of granular material under variable gravity conditions

This paper describes some experiments with granular materials which recently have been conducted aboard the NASA KC-135 aircraft during variable gravity maneuvers. The main experimental apparatus consisted of a small drum containing granular material which was rotated slowly while the angle assumed by the slip surface with respect to the horizontal was observed and recorded photographically. Conventional wisdom has held that this 'dynamic angle of response' was a material constant, independent of (among other things) gravitational level. The results presented here are quite contrary, suggesting instead an angle that varies with the reciprocal of the square root of gravity. This finding may have important consequences on the understanding of many active processes in Planetary Geology involving granular materials and may provide qualitative confirmation of some of the theoretical predictions of modern models of granular shear flows.

White, B. R.↗