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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 289 records · Page 16

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NASA NTRS1977

Light-activated amino acid transport in Halobacterium halobium envelope vesicles

Vesicles prepared from Halobacterium halobium cell envelopes accumulate amino acids in response to light-induced electrical and chemical gradients. Nineteen of 20 commonly occurring amino acids have been shown to be actively accumulated by these vesicles in response to illumination or in response to an artificially created Na+ gradient. On the basis of shared common carriers the transport systems can be divided into eight classes, each responsible for the transport of one or several amino acids: arginine, lysine, histidine; asparagine, glutamine; alanine, glycine, threonine, serine; leucine, valine, isoleucine, methionine; phenylalanine, tyrosine, tryptophan; aspartate; glutamate; proline. Available evidence suggests that these carriers are symmetrical in that amino acids can be transported equally well in both directions across the vesicle membranes. A tentative working model to account for these observations is presented.

Macdonald, R. E.↗

NASA NTRS1988

Convergence speeding up in the calculation of the viscous flow about an airfoil

A finite volume method to solve the three dimensional Navier-Stokes equations was developed. It is based on a cell-vertex scheme with central differences and explicit Runge-Kutta time steps. A good convergence for a stationary solution was obtained by the use of local time steps, implicit smoothing of the residues, a multigrid algorithm, and a carefully controlled artificial dissipative term. The method is illustrated by results for transonic profiles and airfoils. The method allows a routine solution of the Navier-Stokes equations.

Radespiel, R.↗

NASA NTRS1992

Overview of the relevant CFD work at Thiokol Corporation

An in-house developed proprietary advanced computational fluid dynamics code called SHARP (Trademark) is a primary tool for many flow simulations and design analyses. The SHARP code is a time dependent, two dimensional (2-D) axisymmetric numerical solution technique for the compressible Navier-Stokes equations. The solution technique in SHARP uses a vectorizable implicit, second order accurate in time and space, finite volume scheme based on an upwind flux-difference splitting of a Roe-type approximated Riemann solver, Van Leer's flux vector splitting, and a fourth order artificial dissipation scheme with a preconditioning to accelerate the flow solution. Turbulence is simulated by an algebraic model, and ultimately the kappa-epsilon model. Some other capabilities of the code are 2-D two-phase Lagrangian particle tracking and cell blockages. Extensive development and testing has been conducted on the 3-D version of the code with flow, combustion, and turbulence interactions. The emphasis here is on the specific applications of SHARP in Solid Rocket Motor design. Information is given in viewgraph form.

Chwalowski, Pawel↗

DOE OSTI2023

Artificial photosynthetic devices utilizing polariton antennas

An organic photovoltaic device comprises a substrate, a reflector positioned over the substrate, a first electrode positioned over at least a first portion of the reflector, a polaritonic antenna layer positioned over a second portion of the reflector different from the first portion, electrically connected to the first electrode, and at least one unit reaction cell positioned over at least part of the first electrode, the at least one unit reaction cell comprising a heterojunction layer comprising a donor material and an acceptor material, positioned over the first electrode, and a second electrode positioned over the heterojunction, wherein the polaritonic antenna and the reflector are configured to convert incoming photonic energy to polaritons. A method of fabricating an organic photovoltaic device is also disclosed.

Hou, Shaocong↗

DOE OSTI2021

Multifunctional Separator Allows Stable Cycling of Potassium Metal Anodes and of Potassium Metal Batteries

Here, this is the first report of a multifunctional separator for potassium-metal batteries (KMBs). Here, double-coated tape-cast microscale AlF 3 on polypropylene (AlF 3 @PP) yields state-of-the-art electrochemical performance: symmetric cells are stable after 1000 cycles (2000 h) at 0.5 mA cm –2 and 0.5 mAh cm –2 , with 0.042 V overpotential. Stability is maintained at 5.0 mA cm –2 for 600 cycles (240 h), with 0.138 V overpotential. Postcycled plated surface is dendrite-free, while stripped surface contains smooth solid electrolyte interphase (SEI). Conventional PP cells fail rapidly, with dendrites at plating, and “dead metal” and SEI clumps at stripping. Potassium hexacyanoferrate(III) cathode KMBs with AlF 3 @PP display enhanced capacity retention (91% at 100 cycles vs 58%). AlF 3 partially reacts with K to form an artificial SEI containing KF, AlF 3 , and Al 2 O 3 phases. The AlF 3 @PP promotes complete electrolyte wetting and enhances uptake, improves ion conductivity, and increases ion transference number. The higher of K + transference number is ascribed to the strong interaction between AlF 3 and FSI – anions, as revealed through 19 F NMR. The enhancement in wetting and performance is general, being demonstrated with ester- and ether-based solvents, with K-, Na-, or Li- salts, and with different commercial separators. In full batteries, AlF 3 prevents Fe crossover and cycling-induced cathode pulverization.

NMB↗

DOE OSTI2026

Accelerated Selectrion of Optimal Perovskite Alloys for Solar PV using a Combined Quantum and Machine Learning Hierachiral Approach

The project aims to: (i) accelerate the discovery of “Missing HP alloys” by combining quantum mechanics and artificial intelligence machine learning approaches, and (ii) analyze the stabilities of candidate alloys, including those that do not pass selection filters (and are thus expected to degrade over time) to decipher the nature of the instabilities to guide the development of durable solar cell materials. Successful candidates will be subjected to validation experiments at NREL's state-of-the-art facilities. The discoveries this effort will provide will be directly testable and implementable and will greatly impact U.S. progress in HP PV as they will provide clear direction and motivation for experimental studies including specific material synthetic targets, device optimization, and device stability protocols. A key advantage of this effort is the feedback and guidance provided by the Industry Collaborative Work Group that we established to coordinate academic and national lab research with industry needs. The proposed work will provide a basis for and direct the development of robust and reliable HP PV. It will also provide a timely, valuable and extensive roadmap to the experimental HP PV community to enable it to focus its efforts on improving and fine-tuning promising HP compositions that this effort predicts will likely be the best performers rather than wandering in the vast chemical space for decades spending enormous resources mostly evaluating unpromising candidate materials.

14 SOLAR ENERGY↗

NASA NTRS2005

NASA Tech Briefs, February 2005

Topics discussed include: Instrumentation for Sensitive Gas Measurements; Apparatus for Testing Flat Specimens of Thermal Insulation; Quadrupole Ion Mass Spectrometer for Masses of 2 to 50 Da; Miniature Laser Doppler Velocimeter for Measuring Wall Shear; Coherent Laser Instrument Would Measure Range and Velocity; Printed Microinductors for Flexible Substrates; Digital Receiver for Microwave Radiometry; Printed Antennas Made Reconfigurable by Use of MEMS Switches; Traffic-Light-Preemption Vehicle-Transponder Software Module; Intersection-Controller Software Module; Central-Monitor Software Module; Estimating Effects of Multipath Propagation on GPS Signals; Parallel Adaptive Mesh Refinement Library; Predicting Noise From Aircraft Turbine-Engine Combustors; Generating Animated Displays of Spacecraft Orbits; Diagnosis and Prognosis of Weapon Systems; Training Software in Artificial-Intelligence Computing Techniques; APGEN Version 5.0; Single-Command Approach and Instrument Placement by a Robot on a Target; Three-Dimensional Audio Client Library; Isogrid Membranes for Precise, Singly Curved Reflectors; Nickel-Tin Electrode Materials for Nonaqueous Li-Ion Cells; Photocatalytic Coats in Glass Drinking-Water Bottles; Fast Laser Shutters With Low Vibratory Disturbances; Series-Connected Buck Boost Regulators; Space Physics Data Facility Web Services; Split-Resonator, Integrated-Post Vibratory Microgyroscope; Blended Buffet-Load-Alleviation System for Fighter Airplane; Gifford-McMahon/Joule-Thomson Refrigerator Cools to 2.5 K; High-Temperature, High-Load-Capacity Radial Magnetic Bearing; Fabrication of Spherical Reflectors in Outer Space; Automated Rapid Prototyping of 3D Ceramic Parts; Tissue Engineering Using Transfected Growth-Factor Genes; Automation of Vapor-Diffusion Growth of Protein Crystals; Atom Skimmers and Atom Lasers Utilizing Them; Gears Based on Carbon Nanotubes; Patched Off-Axis Bending/Twisting Actuators for Thin Mirrors; and Improving Control in a Joule-Thomson Refrigerator.

Source record↗

DOE OSTI2022

Controlling Protein Enrichment in Lipid Sponge Phase Droplets using SNAP–Tag Bioconjugation

All cells use organized lipid compartments to facilitate specific biological functions. Membrane-bound organelles create defined spatial environments that favor unique chemical reactions while isolating incompatible biological processes. Despite the fundamental role of cellular organelles, there is a scarcity of methods for preparing functional artificial lipid-based compartments. In this work, we demonstrate a robust bioconjugation system for sequestering proteins into zwitterionic lipid sponge phase droplets. Incorporation of benzylguanine (BG)-modified phospholipids that form stable covalent linkages with an O 6 -methylguanine DNA methyltransferase (SNAP-tag) fusion protein enables programmable control of protein capture. We show that this methodology can be used to anchor hydrophilic proteins at the lipid-aqueous interface, concentrating them within an accessible but protected chemical environment. SNAP-tag technology enables the integration of proteins that regulate complex biological functions in lipid sponge phase droplets, and should facilitate the development of advanced lipid-based artificial organelles.

59 BASIC BIOLOGICAL SCIENCES↗

NASA NTRS2007

Rapid Engineering of Three-Dimensional, Multicellular Tissues With Polymeric Scaffolds

A process has been developed for the rapid tissue engineering of multicellular-tissue-equivalent assemblies by the controlled enzymatic degradation of polymeric beads in a low-fluid-shear bioreactor. In this process, the porous polymeric beads serve as temporary scaffolds to support the assemblies of cells in a tissuelike 3D configuration during the critical initial growth phases of attachment of anchorage-dependent cells, aggregation of the cells, and formation of a 3D extracellular matrix. Once the cells are assembled into a 3D array and enmeshed in a structural supportive 3D extracellular matrix (ECM), the polymeric scaffolds can be degraded in the low-fluid-shear environment of the NASA-designed bioreactor. The natural 3D tissuelike assembly, devoid of any artificial support structure, is maintained in the low-shear bioreactor environment by the newly formed natural cellular/ECM. The elimination of the artificial scaffold allows normal tissue structure and function.

Gonda, Steve R.↗

DOE OSTI2020

Research three-dimensional hierarchical graphite architectures for anodes for fast charging

With current lithium ion batteries optimized for performance under relatively low charge rate conditions, implementation of XFC has been hindered by drawbacks including Li plating, kinetic polarization, and heat dissipation. This project will utilize model-informed design of 3-D hierarchical electrodes to tune key XFCrelated variables like 1) bulk porosity/tortuosity 2) vertical pore diameter, spacing, and lattice 3) crystallographic orientation of graphite particles relative to exposed surfaces 4) interfacial chemistry of the graphite surfaces through "artificial sEr' formation using ALD 5) current collector surface roughness (aspect ratio, roughness factor, etc.). A key aspect of implementing novel electrodes is characterizing them in relevant settings. For this project, ultimately led out of University of Michigan by Neil Dasgupta, that includes both coin cell and 2+ Ah pouch cell testing, as well as comparison testing against baselines. Sandia National Labs will be conducting detailed cell characterization on iterative versions/improvements of the model-based hierarchical electrodes, as well as COTS cells for baseline comparisons. Key metrics include performance under fast charge conditions, as well as the absence or degree of lithium plating. Sandia will use their unique high precision cycling and rapid EIS capabilities to accurately characterize performance and any lithium plating during 6C charging and beyond, coupling electrochemical observations with cell teardown. Sandia will also design custom fixturing to cool cells during rapid charge, to decouple any kinetic effects brought about by cell heating and allow comparisons between different cells and charge rates. Using these techniques, Sandia will assess HOH electrodes from the University of Michigan, as well as aiding in iterative model and electrode design.

25 ENERGY STORAGE↗

DOE OSTI2021

Mechanisms of Water-Stimulated Mg 2+ Intercalation in Vanadium Oxide: Toward the Development of Hydrated Vanadium Oxide Cathodes for Mg Batteries

As lithium-ion batteries approach their theoretical limits for energy density, magnesium-ion batteries are emerging as a promising next-generation energy storage technology. However, progress in magnesium-ion battery research has been stymied by a lack of available high capacity cathode materials that can reversibly insert magnesium ions. Vanadium Oxide (V 2 O 5 ) has emerged as one of the more promising candidate cathode materials, owing to its high theoretical capacity, facile synthesis methods, and relatively high operating voltage. This review focuses on the outlook of hydrated V 2 O 5 structures as a high capacity cathode material for magnesium-ion batteries. In general, V 2 O 5 structures exhibit poor experimental capacity for magnesium-ion insertion due to sluggish magnesium-ion insertion kinetics and poor electronic conductivity. However, several decades ago, it was discovered that the addition of water to organic electrolytes significantly improves magnesium-ion insertion into V 2 O 5 . This review clarifies the various mechanisms that have been used to explain this observation, from charge shielding to proton insertion, and offers an alternative explanation that examines the possible role of structural hydroxyl groups on the V 2 O 5 surface. While the mechanism still needs to be further studied, this discovery fueled new research into V 2 O 5 electrodes that incorporate water directly as a structural element. The most promising of these hydrated V 2 O 5 materials, many of which incorporate conductive additives, nanostructured architectures, and thin film morphologies, are discussed. Ultimately, however, these hydrated V 2 O 5 structures still face a significant barrier to potential applications in magnesium-ion batteries. During full cell electrochemical cycling, these hydrated structures tend to leach water into the electrolyte and passivate the surface of the magnesium anode, leading to poor cycle life and low capacity retention. Recently, some promising strides have been made to remedy this problem, including the use of artificial solid electrolyte interphase layers as an anode protection scheme, but a call to action for more anode protection strategies that are compatible with trace water and magnesium metal is required.

25 ENERGY STORAGE↗

DOE OSTI2021

Numerical heating in particle-in-cell simulations with Monte Carlo binary collisions

The binary Monte Carlo (MC) collision algorithm is a standard and robust method to include binary Coulomb collision effects in particle-in-cell (PIC) simulations of plasmas. Here we show that the coupling between PIC and MC algorithms can give rise to (nonphysical) numerical heating of the system that significantly exceeds that observed when these algorithms operate independently. We argue that this deleterious effect results from an inconsistency between the particle motion associated with MC collisions and the work performed by the collective electromagnetic field on the PIC grid. This inconsistency manifests as the (artificial) stochastic production of electromagnetic energy, which ultimately heats the plasma particles. Here, the MC-induced numerical heating can significantly impact the evolution of the simulated system for long simulation times (≳10 3 collision periods, for typical numerical parameters). We describe the source of the MC-induced numerical heating analytically and discuss strategies to minimize it.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗

DOE OSTI2023

Bacterium-enabled transient gene activation by artificial transcription factors for resolving gene regulation in maize

Abstract Understanding gene regulatory networks is essential to elucidate developmental processes and environmental responses. Here, we studied regulation of a maize (Zea mays) transcription factor gene using designer transcription activator-like effectors (dTALes), which are synthetic Type III TALes of the bacterial genus Xanthomonas and serve as inducers of disease susceptibility gene transcription in host cells. The maize pathogen Xanthomonas vasicola pv. vasculorum was used to introduce 2 independent dTALes into maize cells to induced expression of the gene glossy3 (gl3), which encodes a MYB transcription factor involved in biosynthesis of cuticular wax. RNA-seq analysis of leaf samples identified, in addition to gl3, 146 genes altered in expression by the 2 dTALes. Nine of the 10 genes known to be involved in cuticular wax biosynthesis were upregulated by at least 1 of the 2 dTALes. A gene previously unknown to be associated with gl3, Zm00001d017418, which encodes aldehyde dehydrogenase, was also expressed in a dTALe-dependent manner. A chemically induced mutant and a CRISPR-Cas9 mutant of Zm00001d017418 both exhibited glossy leaf phenotypes, indicating that Zm00001d017418 is involved in biosynthesis of cuticular waxes. Bacterial protein delivery of dTALes proved to be a straightforward and practical approach for the analysis and discovery of pathway-specific genes in maize.

59 BASIC BIOLOGICAL SCIENCES↗

NASA NTRS1971

Metabolic effects of artificial environments

The mechanisms by which inert gases influence metabolism were investigated from several viewpoints. Groups of rats were exposed at the thermal neutral temperature of the respective mixtures, to normoxic (P sub A 02 = 100 mm Hq) environments with argon, helium or nitrogen as the diluent at a total pressure of one atmosphere. The possible influence of diluent gases on oxygen transport to the cell was examined with hypoxic (P sub A O2 = 70 mm Hg) mixtures of the same diluent gases. Metabolic measurements included food, water, and oxygen consumption, CO2 production, hematocrit and the rate C-14O2 of expiration subsequent to intraperitoneal injection of acetate-1-C-14 or glucose UL-C-14. Argon-exposed animals showed a consistently decreased metabolic rate while, on the other hand, helium-exposed rats did not significantly alter metabolic rate relative to nitrogen. Certain indices, including acetate and glucose utilization, suggested that helium attenuated the imposed hypoxia at the cellular level while argon facilitated it as compared with nitrogen. These results suggest that metabolic influence of helium is largely thermal in nature while argon has a significant direct metabolic effect and that diluent gases may selectively influence oxygen availability to the interior of the cell.

Jordan, J. P.↗

DOE OSTI2022

High-order dimensionally-split Cartesian embedded boundary method for non-dissipative schemes

Centered finite-difference schemes are commonly used for high-fidelity turbulent flow simulations in canonical configurations because of their non-dissipative property and computational efficiency. However, their use in flow simulations over complex geometries is limited by the requirements of a structured grid and a stable boundary treatment in the absence of artificial (numerical) dissipation. Cartesian embedded boundary (EB) approaches provide an efficient structured-grid framework to apply difference schemes over complex domains. However, they are often restricted to low orders of accuracy because of numerical instabilities at the embedded boundaries and the issues of small-cell problem that are difficult to address with high-order accuracy. The present work discusses a systematic approach to obtain high-order EB methods with non-dissipative centered schemes in the interior. This approach, based on satisfying the primary and secondary conservation conditions, is employed to derive EB schemes that are up to sixth-order accurate in the interior and fourth-order accurate globally for hyperbolic, parabolic as well as incompletely parabolic problems. The proposed finite-difference discretization is, by construction, dimensionally split and addresses the small-cell problem without any cell/geometry transformations, thus, highly simplifying implementation in a flow solver. Various linear and non-linear numerical tests are performed to evaluate the stability and the accuracy of the proposed EB schemes.

97 MATHEMATICS AND COMPUTING↗

NASA NTRS1989

An embedded mesh procedure for leading-edge vortex flows

A cell-vertex scheme is outlined for solving the flow about a delta wing with M (sub infinity) is greater than 1. Embedded regions of mesh refinement allow solutions to be obtained which have much higher resolution than those achieved to date. Effects of mesh refinement and artificial viscosity on the solutions are studied, to determine at what point leading-edge vortex solutions are grid-converged. A macroscale and a microscale for the size of the vortex are defined, and it is shown that the macroscale (which includes the wing surface properties) is converged on a moderately refined grid, while the microscale is very sensitive to grid spacing. The level of numerical diffusion in the core of the vortex is found to be substantial. Comparisons with the experiment are made for two cases which have transonic cross-flow velocities.

Powell, Kenneth G.↗

NASA NTRS2004

A Survey of Collectives

Due to the increasing sophistication and miniaturization of computational components, complex, distributed systems of interacting agents are becoming ubiquitous. Such systems, where each agent aims to optimize its own performance, but where there is a well-defined set of system-level performance criteria, are called collectives. The fundamental problem in analyzing/designing such systems is in determining how the combined actions of self-interested agents leads to 'coordinated' behavior on a iarge scale. Examples of artificial systems which exhibit such behavior include packet routing across a data network, control of an array of communication satellites, coordination of multiple deployables, and dynamic job scheduling across a distributed computer grid. Examples of natural systems include ecosystems, economies, and the organelles within a living cell. No current scientific discipline provides a thorough understanding of the relation between the structure of collectives and how well they meet their overall performance criteria. Although still very young, research on collectives has resulted in successes both in understanding and designing such systems. It is eqected that as it matures and draws upon other disciplines related to collectives, this field will greatly expand the range of computationally addressable tasks. Moreover, in addition to drawing on them, such a fully developed field of collective intelligence may provide insight into already established scientific fields, such as mechanism design, economics, game theory, and population biology. This chapter provides a survey to the emerging science of collectives.

Tumer, Kagan↗

NASA NTRS2005

Microbiological Methodology in Astrobiology

Searching for life in astromaterials to be delivered from the future missions to extraterrestrial bodies is undoubtedly related to studies of the properties and signatures of living microbial cells and microfossils on Earth. As model terrestrial analogs of Martian polar subsurface layers are often regarded the Antarctic glacier and Earth permafrost habitats where alive microbial cells preserved viability for millennia years due to entering the anabiotic state. For the future findings of viable microorganisms in samples from extraterrestrial objects, it is important to use a combined methodology that includes classical microbiological methods, plating onto nutrient media, direct epifluorescence and electron microscopy examinations, detection of the elemental composition of cells, radiolabeling techniques, PCR and FISH methods. Of great importance is to ensure authenticity of microorganisms (if any in studied samples) and to standardize the protocols used to minimize a risk of external contamination. Although the convincing evidence of extraterrestrial microbial life will may come from the discovery of living cells in astromaterials, biomorphs and microfossils must also be regarded as a target in search of life evidence bearing in mind a scenario that alive microorganisms had not be preserved and underwent mineralization. Under the laboratory conditions, processes that accompanied fossilization of cyanobacteria were reconstructed, and artificially produced cyanobacterial stromatolites resembles by their morphological properties those found in natural Earth habitats. Regarding the vital importance of distinguishing between biogenic and abiogenic signatures and between living and fossil microorganisms in analyzed samples, it is worthwhile to use some previously developed approaches based on electron microscopy examinations and analysis of elemental composition of biomorphs in situ and comparison with the analogous data obtained for laboratory microbial cultures and fossilized microorganisms. This communication will be focused on the analysis of our experience in working with ancient microorganisms and fossils and discussion of some issues that are crucial for development of the program for future finding of extraterrestrial life and its evidence.

Abyzov, S. S.↗