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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 1,171 records · Page 65
All sourcesNASA NTRSDOE OSTI
NASA NTRS2022

Compound Effects of Climate Change on Future Transboundary Water Issues in the Middle East

The Middle East is one of the world’s most vulnerable areas to climate change, which has exacerbated environmental, agricultural, water conflict, and public health issues in the region. Here we analyze the latest climate model projections of precipitation and temperature for the very high emissions scenario, SSP5-8.5,to detect potential future changes in this region. A baseline period (1981-2010) is compared with the middle(2040-2069) and end (2070-2099) of the 21stcentury. The results, representing the worst-case scenario, identify the Tigris-Euphrates headwaters as the hotspot of future compounding effects of climate change in the Middle East. Those effects result from the coincidence of elevated temperature, reduced precipitation, and enhanced interannual variability of precipitation. The hotspot overlays the location of the Southeastern Anatolia Project (in Turkish, GAP) irrigation initiative. In this climate context, risks to GAP viability and downstream water security, and associated potential for water-related conflicts and migration are considerable and demand a reconsideration of the risk-benefit assessment of GAP. This need has become more urgent after the recent widespread and deadly climate-related conflicts and wildfires in summer 2021 across the Middle East that further underlined vulnerability of the region to climate extremes.

Tigris-Euphrates headwater↗
NASA NTRS2023

CALPHAD Models to Guide Refractory Alloys Additive Manufacturing: In-Situ Compounds Formation, Nanoparticles, and Impurities Considerations

This technical memorandum (TM) seeks to model and discuss aspects of nanoparticle and micrometer-scale particle or ‘microparticle’ inclusions in refractory metal alloy manufacturing, via a currently used additive manufacturing (AM) method that results in equivalent wt.% addition of dissolved elements in the melt pool composition and subsequent formation of nanometer-scale MC and MO inclusions. Additionally, the authors begin to consider the effects of oxygen (O), a ubiquitous impurity, in AM; and seek to understand a combined optimization of alloying, nano- and micro strengthening and refinement, elemental additions, and even in-situ compounds and alloys species formation. To gain insights, this TM focuses on a pair of refractory alloys currently of interest to NASA: tungsten-rhenium-tantalum carbide (with O impurities) (W-Re-TaC(-O)) and tungsten-rhenium-tantalum-carbon (with O impurities) (W-Re-Ta-C(-O)), which are processed via powder bed fusion (PBF)-SLM.

ICME integrated computational materials engineerin↗
NASA NTRSDate not supplied

Vapor Growth of ZnSe-based Compound Semiconductors in Low Gravity environment on International Space Station

Six low-gravity experiments of crystal growth of ZnSe-based compound semiconductors by physical vapor transport (PVT) are scheduled to be processed inside Low Gradient Furnace (LGF) on Materials Science Research Rack (MSRR) in Material Science Laboratory (MSL) on International Space Station (ISS) starting from February 27th, 2023. The flight samples consist of three unseeded growths of ZnSe, Cr-doped ZnSe and ZnSeTe as well as growth of ZnSe on top of three single crystal ZnSe seeds with orientation of (100), (110) and (111). The main scientific objective of the flight experiments is to establish the effects of gravity-driven fluid flows on Earth to (i) the non-uniform incorporation of impurities and defects and (ii) the deviation from stoichiometry observed in the grown crystals caused by growth interface fluctuations and evolution as the results of buoyancy-driven convection and irregular fluid-flows. The investigation will also evaluate the effects of gravity on the PVT process by examining (i) the growth kinetics on various seed orientations, (ii) the dopant segregation and distribution in the Cr doped ZnSe, and (iii) the compositional segregation and distribution in the ternary ZnSeTe crystal grown by PVT. Additionally, from X-ray diffraction/topography and by measuring the density and distribution of various crystalline defects it will assess the self-induced strain effects developed during processing at elevated temperatures caused by the weight of the crystals. During the ground-based preparations, the following tasks have been accomplished: • Establish the thermodynamic properties of the ZnSe binary and related ternary systems by measuring the partial pressures of the vapor phase coexisting with the condensed phases and perform phase diagram calculations for comparison. • Evaluate the effects of gravity-driven convection in the growth process by performing experiments under various vapor transport orientations relative to gravity vector, i.e., horizontal, vertically stabilized and destabilized configurations. • Establish a quantitative correlation between growth parameters and the characteristics and properties of the grown crystals by characterizing the crystals using a variety of techniques. • Evaluate the fundamentals of the current theories on vapor transport and crystal growth kinetics by performing in-situ and real-time monitoring techniques during growth. • Develop a one-dimensional diffusion limited theory of mass transport and two- and three-dimensional numerical simulations of both mass transport and heat transfer and thus establish the microgravity requirements for the flight experiments and to predict the characteristics of the grown crystals such as the solid-vapor interface shapes… etc. and establish a fundamental understanding of the crystal growth process from the comparison with experimental results.

ZnSe↗
NASA NTRS2024

Development of the Volatile Organic Compound (VOC) Removal System Final Report

The United States, along with other countries around the world, is preparing to return humankind to the Lunar surface. This endeavor will require the development of new technologies if a human presence beyond the Earth’s sphere of influence is to be maintained. Indeed, during the space race of the 20th century, a mere twelve astronauts traveled to the Moon and returned to Earth. Now, in the 21st century as we prepare to travel back to the Moon and on to Mars a more substantial effort will be needed to develop how astronauts can sustain themselves for long duration. Among the technologies that need further development are CO 2 and removal along with the removal of volatile organic compounds (VOCs). Long-term human exploration necessitates CO 2 and VOC removal systems which require little to no maintenance, i.e., no sorbent materials. Currently, NASA AMES is developing a CO 2 Deposition System (CDep) which does not rely on sorbent materials. Rather, by chilling the incoming air the system is able to “freeze-out” the CO 2 while allowing oxygen and nitrogen to pass through the system. However, this system in its current configuration is unable to filter out all VOCs. Therefore, it is necessary to further develop this system with the addition of a VOC removal element to provide a complete solution to the long-term problem of air revitalization in a safe and reliable manner.

Nilton De Oliveira Renno↗
DOE OSTI2020

Compounds for reactivation of acetylcholinesterase and related compositions methods and systems

Described herein are oxime compounds capable of inactivating a nerve agent, blood brain barrier (BBB)-penetration, and/or reactivation of nerve agent-inhibited acetylcholinesterase (AChE) and related methods, systems and compositions for inactivation of one or more nerve agents, therapeutic and/or prophylactic treatment of an individual, and/or decomposition of nerve agent for decontamination.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2020

Reactor with advanced architecture for the electrochemical reaction of CO2, CO, and other chemical compounds

A platform technology that uses a novel membrane electrode assembly including a cathode layer comprising a reduction catalyst and a first anion-and-cation-conducting polymer, an anode layer comprising an oxidation catalyst and a cation-conducting polymer, a membrane layer comprising a cation-conducting polymer, the membrane layer arranged between the cathode layer and the anode layer and conductively connecting the cathode layer and the anode layer, in a COx reduction reactor has been developed. The reactor can be used to synthesize a broad range of carbon-based compounds from carbon dioxide.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2020

Detecting compounds in microfluidic droplets using mass spectrometry

Disclosed herein are devices and methods for detecting compounds in droplets using mass spectrometry. In some embodiments, the device comprises: a microfluidics-MS (microMS) device, wherein the microMS device comprises: a droplet-to-digital microfluidic device, wherein the droplet-to-digital microfluidic device comprises: a glass layer; an electrode layer comprising chrome electrodes etched onto one side of the glass layer; a dielectric layer configured for electrowetting; and a microfluidics layer comprising channels, pockets, and a droplet generator, for example a T-junction droplet generator, wherein the pockets are connected to the channels; and a mass spectrometry plate, wherein the mass spectrometry plate is reversibly sealed to the microfluidic device.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2020

Reactor with advanced architecture for the electrochemical reaction of CO2, CO and other chemical compounds

A platform technology that uses a novel membrane electrode assembly, including a cathode layer, an anode layer, a membrane layer arranged between the cathode layer and the anode layer, the membrane conductively connecting the cathode layer and the anode layer, in a COx reduction reactor has been developed. The reactor can be used to synthesize a broad range of carbon-based compounds from carbon dioxide and other gases containing carbon.

Kuhl, Kendra P.↗
DOE OSTI2020

In vitro methods for processing lignin and other aromatic compounds

Enzymes for depolymerizing lignin. The enzymes include dehydrogenases, β-etherases, and glutathione lyases. The dehydrogenases can comprise one or more or LigD, LigO, LigN, and LigL. The β-etherases can comprise one or more of LigE, LigF, LigP, and BaeA. The glutathione lyases can comprise any one or more of LigG and a number of non-stereospecific, optionally recombinant glutathione lyases derived from Sphingobium sp. SYK-6, Novosphingobium aromaticivorans, Escherichia coli, Streptococcus sanguinis, Phanerochaete chrysosporium, and other microorganisms. The enzymes can be combined in compositions and/or used in methods of processing lignin or other aromatic compounds in vitro.

Donohue, Timothy James↗
DOE OSTI2021

An automated approach to the alignment of compound refractive lenses

Compound refractive lenses (CRLs) are established X-ray focusing optics, and are thus a key element of many beamlines at X-ray facilities, used to either to focus a beam or image a sample. While CRLs are quite established, the stack of single lens elements affords a very small numerical aperture because of the thick lens profile, making them far more difficult to align than classical optical lenses that obey the thin-lens approximation. This means that the alignment must be very precise and is highly sensitive to changes to the incident beam; aligning CRLs is thus typically treated as a time-consuming manual process. Many groups circumvent day-to-day realignment by using engineering controls (e.g. mounting optics) that sacrifice some of the beam’s focusing characteristics, i.e. spot size, or resolution. While these choices minimize setup time, there are clear disadvantages. This work presents a new automated approach to align CRLs using a simple alignment apparatus that is easy to adapt and install at different types of X-ray experiments or facilities. Our approach builds on recent CRL modeling efforts, using an approach based on the Stochastic Nelder-Mead (SNM) simplex method. We demonstrate the efficacy of this method by numerical simulation and then extend this test to real experiments conducted at the Advanced Photon Source to confirm its performance with a synchrotron X-ray beam. This work provides an opportunity to automate key instrumentation at X-ray facilities.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2021

Polycarboxylated compounds and compositions containing same

Methods of selectively modifying lignin, polycarboxylated products thereof, and methods of deriving aromatic compounds therefrom. The methods comprise electrochemically oxidizing lignin using stable nitroxyl radicals to selectively oxidize primary hydroxyls on β-O-4 phenylpropanoid units to corresponding carboxylic acids while leaving the secondary hydroxyls unchanged. The oxidation results in polycarboxylated lignin in the form of a polymeric β-hydroxy acid. The polymeric β-hydroxy acid has a high loading of carboxylic acid and can be isolated in acid form, deprotonated, and/or converted to a salt. The β-hydroxy acid, anion, or salt can also be subjected to acidolysis to generate various aromatic monomers or oligomers. The initial oxidation of lignin to the polycarboxylated form renders the lignin more susceptible to acidolysis and thereby enhances the yield of aromatic monomers and oligomers obtained through acidolysis.

Stahl, Shannon S.↗
DOE OSTI2021

Reactor with advanced architecture for the electrochemical reaction of CO2, CO, and other chemical compounds

A platform technology that uses a novel membrane electrode assembly including a cathode layer comprising a reduction catalyst and a first anion-and-cation-conducting polymer, an anode layer comprising an oxidation catalyst and a cation-conducting polymer, a membrane layer comprising a cation-conducting polymer, the membrane layer arranged between the cathode layer and the anode layer and conductively connecting the cathode layer and the anode layer, in a COx reduction reactor has been developed. The reactor can be used to synthesize a broad range of carbon-based compounds from carbon dioxide.

Kuhl, Kendra P.↗
DOE OSTI2021

Organic-inorganic hybrid perovskite compounds

Photoactive materials comprising organic-inorganic hybrid halide perovskite compounds are provided. Photovoltaic cells and light-emitting devices incorporating the photoactive materials into their light-absorbing and light-emitting layers, respectively, are also provided. The halide perovskites have an amAMX3 perovskite crystal structure, wherein am is an alkyl diamine cation, an aromatic diamine cation, an aromatic azole cation, a cyclic alkyl diamine cation or a hydrazinediium cation; A is a monovalent alkylammonium cation or an alkali metal cation; X is a halide ion or a combination of halide ions; and M is an octahedrally coordinated bivalent metal atom.

Ke, Weijun↗
DOE OSTI2022

Chemical Kinetics Underlying the Sooting Tendency and Auto-Ignition Characteristics of Linear, Branched, and Cyclic Ether Compounds

Biofuels present opportunities for improving the performance and reducing emissions from internal combustion engines by incorporating oxygenated functional groups to the fuels. Among various oxygenates, ethers have been recognized as promising candidates for an alternative to conventional diesel fuel owing to their higher reactivity and lower sooting tendency. The detailed guidelines for designing ethers, however, have not been fully discussed, even though their combustion characteristics are sensitive to the molecular structure. This study was devoted to exploring the structure-property relationships, particularly focusing on the cetane number and yield sooting index, using five linear, branched, and cyclic ethers: di-amyl-ether, 4-butoxy-heptane, 3,3-dimethyl-oxetane, 2-ethyl-4-methyl-1,3-dioxolane, and 2-isopropyl-4-methyl-1,3-dioxolane. First, we examined the chemical kinetics underlying the sooting tendency of the test fuels. The combustion product distribution was measured from flow reactor experiments at 750-1100 K, F=3, at atmospheric pressure. As a result, it was revealed that the sooting tendency is closely related to the size of hydrocarbon intermediates in the high-temperature regime (>1000 K); that is, larger hydrocarbons lead to more soot precursor formation. The underlying chemistry determining the size of the hydrocarbons from the tested fuels was analyzed using reaction pathway analysis and quantum mechanics calculations, which showed that the branched and cyclic ether structures form abundant C3-C4 compounds. Moreover, the auto-ignition characteristics of the test fuels were studied using the flow reactor at low-temperature (400-700 K) and F=1. We found a clear difference in the combustion-product distribution from high and low reactivity fuels, which was then correlated to the systematic analysis of the key reaction energy barriers with the varying molecular structure.

BIOMASS FUELS,INORGANIC, ORGANIC, PHYSICAL, AND AN↗
DOE OSTI2022

Lens-free compound eye cameras based on angle-sensitive meta-surfaces

A lens-free ultrathin imaging sensor using a compound-eye vision modality can be formed by forming a metasurface on each pixel of an array of pixels in a solid state imaging sensor. The metasurface can be configured to form a diffraction grating that directs light incident on the metasurface at a predefined angle to excite surface plasmon polaritons into the solid state imaging sensor and light incident at any other angle is reflected or diffracted away from the metasurface. Each pixel of the imaging sensor can be configured using the metasurface to only receive light incident from a different portion of a field of view. A computational imaging system can be used to construct the image from the individual pixels.

Paiella, Roberto↗
DOE OSTI2022

Processes for separation of aromatic compounds using a thin film composite membrane

This invention discloses a method for separation of an aromatic compound from a mixture comprising an alkane using an improved thin-film composite membrane. The membrane is particularly useful for separation of benzene from cyclohexane, which have similar boiling points. The membrane comprises a more mechanically durable and defect-free separation layer as a result of its fabrication from an ionomer solution that is substantially free of dissolved ionic species not associated with the ionomer.

Majumdar, Sudipto↗