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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 703 records · Page 39
All sourcesNASA NTRSDOE OSTI
DOE OSTI2023

Scalable photonic integrated circuits for high-fidelity light control

Advances in laser technology have driven discoveries in atomic, molecular, and optical (AMO) physics and emerging applications, from quantum computers with cold atoms or ions, to quantum networks with solid-state color centers. This progress is motivating the development of a new generation of optical control systems that can manipulate the light field with high fidelity at wavelengths relevant for AMO applications. These systems are characterized by criteria: (C1) operation at a design wavelength of choice in the visible (VIS) or near-infrared (IR) spectrum, (C2) a scalable platform that can support large channel counts, (C3) high-intensity modulation extinction and (C4) repeatability compatible with low gate errors, and (C5) fast switching times. Here, we provide a pathway to address these challenges by introducing an atom control architecture based on VIS-IR photonic integrated circuit (PIC) technology. Based on a complementary metal–oxide–semiconductor fabrication process, this atom-control PIC (APIC) technology can meet system requirements (C1)–(C5). As a proof of concept, we demonstrate a 16-channel silicon-nitride-based APIC with (5.8±0.4)ns response times and >30dB extinction ratio at a wavelength of 780 nm.

Menssen, Adrian J.↗
DOE OSTI2023

Design and Modeling of an 80 bar Oxy-Combustor for Direct Fired Supercritical CO2 Applications

As supercritical CO2 power cycles for fossil energy power generation continue to generate interest, there are significant issues and unanswered questions regarding injector design, flame stabilization, wall heat transfer, CO emissions, combustion dynamics and other combustion phenomenon. For natural gas, direct-fired cycles with carbon capture it is believed that Computational Fluid Dynamics (CFD) modeling will play an essential role in the combustor design process. To accurately model turbulent reacting flows at these unique conditions, experimental data is needed to validate CFD codes and sub-models and is currently lacking at conditions relevant for these cycles. This paper presents the conceptual design and CFD simulations of an experimental 80 bar oxy-combustion facility and test article currently under construction at NETL. The facility is targeted towards the testing of a single injector, direct-fired sCO2 combustor at the 100 kW thermal output level. While these conditions do not reflect the actual Allam cycle operating conditions (300 bar) they are viewed as a stepping stone in the model validation process at supercritical conditions. Reynolds Averaged Navier-Stokes as well as Large Eddy Simulation are used to model the turbulent combustion process and aid in the design of the combustor and injector. Process parameters including oxidizer preheat temperature and combustor flowrate are investigated.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2024

KBase Narrative - van den Bergh et al

We report 14 metagenome-assembled genomes (MAGs) recovered from agricultural soils, composts, and enrichment cultures enriched therefrom, originating from the Netherlands, Belgium and Switzerland. Recovered MAGs constitute methane-cycling related organisms sequenced from isolated cultures or environmental DNA, elucidating their metabolic potential in important ecological processes like the oxidation or production of atmospheric trace gases as methane, hydrogen, and carbon monoxide.

Rocha, Gabriel Silvestre↗
DOE OSTI2024

Observing low-altitude features in ozone concentrations in a shoreline environment via uncrewed aerial systems

Abstract. Ozone is a pollutant formed in the atmosphere by photochemical processes involving nitrogen oxides (NOx) and volatile organic compounds (VOCs) when exposed to sunlight. Tropospheric boundary layer ozone is regularly measured at ground stations and sampled infrequently through balloon, lidar, and crewed aircraft platforms, which have demonstrated characteristic patterns with altitude. Here, to better resolve vertical profiles of ozone within the atmospheric boundary layer, we developed and evaluated an uncrewed aircraft system (UAS) platform for measuring ozone and meteorological parameters of temperature, pressure, and humidity. To evaluate this approach, a UAS was flown with a portable ozone monitor and a meteorological temperature and humidity sensor to compare to tall tower measurements in northern Wisconsin. In June 2020, as a part of the WiscoDISCO20 campaign, a DJI M600 hexacopter UAS was flown with the same sensors to measure Lake Michigan shoreline ozone concentrations. This latter UAS experiment revealed a low-altitude structure in ozone concentrations in a shoreline environment showing the highest ozone at altitudes from 20–100 m a.g.l. These first such measurements of low-altitude ozone via a UAS in the Great Lakes region revealed a very shallow layer of ozone-rich air lying above the surface.

Meteorology & Atmospheric Sciences↗
NASA NTRS1974

Some recent developments in spacecraft environmental control/life support subsystems

The subsystems considered include a flash evaporator for heat rejection, a regenerable carbon dioxide and humidity control subsystem, an iodinating subsystem for potable water, a cabin contaminant control subsystem, and a wet oxidation subsystem for processing spacecraft wastes. The flash evaporator discussed is a simple unit which efficiently controls life support system temperatures over a wide range of heat loads. For certain advanced spacecraft applications the control of cabin carbon dioxide and humidity can be successfully achieved by a regenerable solid amine subsystem.

Gillen, R. J.↗
NASA NTRS1975

Silicon ions below 100 km - A case for SiO2/+/

An investigation regarding the occurrence of Si ions is conducted, taking into account an unusual metal ion structure observed during a meteor shower event. Loss processes involving silicon oxides are considered in connection with a study of the reasons for the unique Si(+) distribution found. It is suggested that below 100 km Si(+) is rapidly depleted by two- and three-body reactions with molecular oxygen, forming SiO2(+) which then recombines.

Goldberg, R. A.↗
NASA NTRS1978

Investigation of the effect of ceramic coatings on rocket thrust chamber life

Cylindrical rocket thrust chamber cylinders were coated with a 0.203 mm (0.008 in.) layer of zirconium oxide using a process that employed electrodeposition of metal to a spray coated mandrel. The cylinders were cyclically tested using hydrogen oxygen propellants at a nominal chamber pressure of 4.14 MN/sq m (600 psia) to show the effect of the coating on life. Both cylinders failed prematurely due to causes unrelated to the coatings. Post destructive analysis showed no cooling passage wall deformation. Where erosion of the coating occurred, the coating thickness stabilized at 0.061 mm (0.0024 in.) within 80 cycles and remained well adhered throughout the tests.

Quentmeyer, R. J.↗
NASA NTRS1978

Investigation of the effect of ceramic coatings on rocket thrust chamber life

Two cylindrical rocket thrust chamber cylinders were coated with a 0.203 mm layer of zirconium oxide using a process that employed electrodeposition of metal to a spray-coated mandrel. The cylinders were cyclically tested using hydrogen-oxygen propellants at a nominal chamber pressure of 4.14 MN/sq m to show the effect of the coating on life. Both cylinders failed prematurely due to causes unrelated to the coatings. Post destructive analysis showed no cooling passage wall deformation. Where erosion of the coating occurred, the coating thickness stabilized at 0.061 mm within 80 cycles and remained well adhered throughout the tests. The hot-gas-side metal wall temperature and the theoretical maximum effective strain were reduced by 80 and 92%, respectively, where the coating was 0.203 mm thick and by 40 and 50%, respectively, where the coating was 0.061 mm thick compared to an uncoated cylinder. The 50 and 92% reductions in maximum effective strain resulted in theoretical lives of 1900 cycles and greater than 10,000 cycles, respectively, compared to 300 cycles for the uncoated cylinder.

Quentmeyer, R. J.↗
NASA NTRS1979

CMOS circuit-fabrication handbook

Report describes complementary metal-oxide-semiconductor (CMOS) process used to fabricate integrated circuits at Marshall Space Flight Center. It also presents general discussions of circuit design, mask making packaging, and testing.

Bouldin, D. L.↗
NASA NTRS1980

Design rules for CMOS/SOS circuits

Report presents design rules for advanced-technology integrated circuits made by self-aligned silicongate complementary - metal - oxide - semiconductor/silicon-on-sapphir (CMOS/SOS) process.

Source record↗
NASA NTRS1979

In situ self cross-linking of polyvinyl alcohol battery separators

A battery separator was produced from a polyvinyl alcohol sheet structure which was subjected to an in situ, self crosslinking process by selective oxidation of the 1,2 diol units present in the polyvinyl alcohol sheet structure. The 1,2 diol units were cleaved to form aldehyde end groups which subsequently crosslink through acetalization of the 1,3 diol units of the polyvinyl alcohol. Selective oxidation was achieved using a solution of a suitable oxidizing agent such as periodic acid or lead tetraacetate.

Philipp, W. H.↗
NASA NTRS1981

Satellite and surface geophysical expression of anomalous crustal structure in Kentucky and Tennessee

An equivalent layer magnetization model is discussed. Inversion of long wavelength satellite magnetic anomaly data indicates a very magnetic source region centered in south central Kentucky. Refraction profiles suggest that the source of the gravity anomaly is a large mass of rock occupying much of the crustal thickness. The outline of the source delineated by gravity contours is also discernible in aeromagnetic anomaly patterns. The mafic plutonic complex, and several lines of evidence are consistent with a rift association. The body is, however, clearly related to the inferred position of the Grenville Front. It is bounded on the north by the fault zones of the 38th Parallel Lineament. It is suggested that such magnetization levels are achieved with magnetic mineralogies produced by normal oxidation and metamorphic processes and enhanced by viscous build-up, especially in mafic rocks of alkaline character.

Mayhew, M. A.↗
NASA NTRS1985

Graphite/PMR polyimide composites with improved toughness

The toughness of composites made with modified PMR (polymerization of monomer reactants) polyimides and Celion 6000 graphite fibers was studied. Various types/levels of monomer reactants containing flexible links were incorporated into PMR resin compositions used to prepare composites. The composites were evaluated for toughness using instrumented drop weight and 10 deg off axis tensile tests at room temperature, and for strength using flexure and short beam shear tests at room temperature and at elevated temperature. The effect of resin composition on composite processability, thermo-oxidative stability, toughness and mechanical properties are discussed.

Vannucci, R. D.↗
NASA NTRS1985

Planetary ecology; Proceedings of the Sixth International Symposium on Environmental Biogeochemistry, Santa Fe, NM, October 10-14, 1983

Topics presented include biological evolution and planetary chemistry; C-1 compounds; transport, deposition, and weathering; sulfur transformations; ground water; transformation processes for nitrogen oxides; and soils. Papers are presented on immunological studies on the organic matrix of recent and fossil invertebrate shells; biogenic gases in sediments deposited since Miocene times on the Walvis Ridge, South Atlantic Ocean; aspects of the biogeochemistry of Big Soda Lake, NV; mesophilic manganese-oxidizing bacteria from hydrothermal discharge areas at 21 deg North on the East Pacific Rise; and autotrophic growth and iron oxidation and inhibition kinetics of Leptospirillum ferrooxidans. Consideration is also given to thermophilic archaebacteria occurring in submarine hydrothermal areas; fate of sulfate in a soft-water, acidic lake; geochemical conditions in the ground water environment; microbial transformations as sources and sinks for nitrogen oxides; and the biogeochemistry of soil phosphorus.

Caldwell, D. E.↗
NASA NTRS1985

Graphite/PMR polyimide composites with improved toughness

The toughness of composites made with modified PMR (Polymerization of monomer reactants) polyimides and Celion 6000 graphite fibers was studied. Various types/levels of monomer reactants containing flexible links were incorporated into PMR resin compositions used to prepare composites. The composites were evaluated for toughness using instrumented drop weight and 10 deg off axis tensile tests at room temperature, and for strength using flexure and short beam shear tests at room temperature and at elevated temperature. The effect of resin composition on composite processability, thermo-oxidative stability, toughness and mechanical properties are discussed.

Vannucci, R. D.↗
NASA NTRS1987

Vertical O(sub 3) distribution as a diagnostic for eddy diffusion profile

A model study of the distribution of ozone on Mars is presented. It is showed that knowledge of the vertical ozone distribution, such as could be obtained from ultraviolet measurements from an orbiter, could be used to infer vertical transport rates at various levels in the atmosphere. The dependence of the vertical distribution of O(sub 3) on the height variation of eddy diffusion coefficient is illustrated. Ozone abundance is a valuable diagnostic for other climatological parameters. In addition, the sensitivity of O(sub 3) distribution to eddy diffusion may aid in determining the role of surface oxidation and recombination processes and lead to a better understanding of the volatiles released or adsorbed cyclically in the Martian regolith.

Tyler, A. L.↗
NASA NTRS1993

Corrosion of Silicon-Based Ceramics in Combustion Environments

The processes of passive oxidation, deposit-induced corrosion, active oxidation, scale/substance interactions, and scale volatility are presently studied in the case of high-purity SiC and Si3N4 in pure oxygen, giving attention to such secondary elements in the ceramics as water and CO2 oxidants, combustion environment impurities, and thermal cycling. Deposit-induced corrosion is discussed for the cases of NaSO4 as well as vanadate and oxide-slag deposits; issues associated with the active-to-passive oxidation transition are noted.

Jacobson, Nathan S.↗
NASA NTRS1994

Frictional behavior and adhesion of Ag and Au films applied to aluminum oxide by oxygen-ion assisted Screen Cage Ion Plating (SCIP)

A modified dc-diode ion plating system, by utilizing a metallic screen cage as a cathode, is introduced for coating nonconductors such as ceramics. Screen cage ion plating (SCIP) is used to apply Ag and Au lubricating films on aluminum oxide surfaces. This process has excellent ability to coat around corners to produce three-dimensional coverage of the substrate. A dramatic increase in adhesion is achieved when plating is performed in a reactive 50 percent O2 - 50 percent Ar glow discharge compared to the adhesion when plating is performed in 100 percent Ar. The presence of oxygen ion assistance contributes to the excellent adhesion as measured in a pull-type adhesion tester. The Ag and Au film adhesion is significantly increased (less than 70MPa) and generally exceeds the cohesion of the substrate such that portions of the alumina are pulled out.

Spalvins, Talivaldis↗