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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 235 records · Page 13
All sourcesNASA NTRSDOE OSTI
NASA NTRS1971

Mixing models and the recognition of end-member groups in Apollo 11 and 12 soils.

Lunar soils returned from the Apollo 11 and 12 sites appear to consist of more than one source material. Investigators have suggested that the soil can be described by as few as two end members and possibly as many as five or six. In the present study Q-mode factor analysis is used to establish the end members more rigorously and suggests that major-element chemistry of Apollo 11 and 12 lunar soils can be adequately explained in terms of a three-component mixing system. The end members isolated by Q-mode factor analysis can be regarded as basaltic, anorthositic, and noritic (or KREEP) components. Three-component mixing models fitted by least squares to the eight major oxides indicate that six of the Apollo 12 soils investigated are dominated by the basaltic component, whereas the other five are dominated by the noritic or KREEP component. Anorthosite is present in all soils except sample 12033, which is a simple two-component mixture of basalt and KREEP. The Apollo 11 soil is also a three-component mixture but is more basaltic than the Apollo 12 soils. Anorthositic and KREEP materials are important components of the lunar lithosphere and may be distributed on the lunar surface areally in an independent manner.

Lindsay, J. F.↗
NASA NTRS1974

A high power TWT power processing system

A power processing system (PPS) is designed for a space-type high power (200W RF) multi-collector traveling-wave tube (TWT). The basic power circuit is presented along with the simplified block diagram and the input, output, and general requirements for the PPS design are tabulated. The paper covers the PPS design as to critical TWT/PPS interface requirements, high voltage cathode/collector supply, high voltage components material, packaging, grounding and isolation, and electrical performance. The use of a single two loop control system for the regulation of cathode and collector voltages is shown to give high efficiency, excellent steady-state and transient performance characteristics, and complete protection for TWT and PPS components under transient conditions.

Farber, B. F.↗
NASA NTRS1990

Use of high-dimensional spectral data to evaluate organic matter, reflectance relationships in soils

Recent breakthroughs in remote sensing technology have led to the development of a spaceborne high spectral resolution imaging sensor, HIRIS, to be launched in the mid-1990s for observation of earth surface features. The effects of organic carbon content on soil reflectance over the spectral range of HIRIS, and to examine the contributions of humic and fulvic acid fractions to soil reflectance was evaluated. Organic matter from four Indiana agricultural soils was extracted, fractionated, and purified, and six individual components of each soil were isolated and prepared for spectral analysis. The four soils, ranging in organic carbon content from 0.99 percent, represented various combinations of genetic parameters such as parent material, age, drainage, and native vegetation. An experimental procedure was developed to measure reflectance of very small soil and organic component samples in the laboratory, simulating the spectral coverage and resolution of the HIRIS sensor. Reflectance in 210 narrow (10 nm) bands was measured using the CARY 17D spectrophotometer over the 400 to 2500 nm wavelength range. Reflectance data were analyzed statistically to determine the regions of the reflective spectrum which provided useful information about soil organic matter content and composition. Wavebands providing significant information about soil organic carbon content were located in all three major regions of the reflective spectrum: visible, near infrared, and middle infrared. The purified humic acid fractions of the four soils were separable in six bands in the 1600 to 2400 nm range, suggesting that longwave middle infrared reflectance may be useful as a non-destructive laboratory technique for humic acid characterization.

Henderson, T. L.↗
NASA NTRS1983

Life considerations of the shuttle orbiter densified-tile thermal protection system

The Shuttle orbiter themal protection system (TPS) incorporates ceramic reusable surface insulation tiles bonded to the orbiter substructure through a strain isolation pad. Densification of the bonding surface of the tiles increases the static strength of the tiles. The densification proces does not, however, necessarily lead to an equivalent increase in fatigue strength. Investigation of the expected lifetime of densified tile TPS under both sinusoidal loading and random loading simulating flight conditions indicates that the strain isolation pads are the weakest components of the TPS under fatigue loading. The felt pads loosen under repetitive loading and, in highly loaded regions, could possibly cause excessive step heights between tiles causing burning of the protective insulation between tiles. A method of improving the operational lifetime of the TPS by using a strain isolation pad with increased stiffness is presented as is the consequence of the effect of increased stiffness on the tile inplane strains and transverse stresses.

Cooper, P. A.↗
DOE OSTI2021

Diagnostic Testing for COVID-19 Bridging Study for QIAamp Viral RNA Extraction vs Beckman RNAdvance vs Thermofisher MagMAX

This report describes testing that was performed by LANL’s Biological Agent Testing Lab (BATL) to validate modifications to the CDC EUA 2019-Novel Coronavirus (2019- nCoV) Real-Time RT-PCR Diagnostic Panel (EUA-CDC-nCoV-IFU). BATL intends to implement the modifications to increase thoughput for daily testing . BATL validated the viral RNA extraction process, using the orignial component, QIAamp Viral RNA Mini Kit (Cat # 52906) and the new components, Beckman Coulter magnetic 96-well plate RNAdvance Viral kit (Cat # C63510), Thermofisher MagMAX Viral/Pathogen Nucleic Acid Isolation Kit (Cat # A48310). Equivalency was demonstrated between the original component and the Beckman Coulter magnetic 96-well plate RNAdvance Viral kit (Cat # C63510). Equivalency was also demonstrated between the original component and the Thermofisher MagMAX Viral/Pathogen Nucleic Acid Isolation Kit (Cat # A48310). Subsequently, substitution of the original component with either of these kits for viral RNA extraction increased BATL’s extraction capability from 100 samples per day to 279 samples per day.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2024

Description of FY25 Theory and Simulation Performance Target: Development of an integrated modeling framework for fusion reactor design and assessment

The urgency to deliver fusion power is growing now more than ever, with increasing pressure for both public programs and private companies to meet milestones timelines and overcome significant remaining technical challenges to ensure growth of a nascent fusion industry in time to meet rapidly growing clean energy demands. With incredible advancements in computation and years of investment in fusion model development and validation, integrated modeling is poised to fill a key role in accelerating the timeline to a fusion pilot plant (FPP). Future fusion pilot plants will operate in regimes far beyond current experience, and device design will rely on physics-based prediction and extrapolation. Many concepts will also rely on simulation to assess safety (shielding, tritium management, materials activation and lifetimes), economics and scalability before the decision to build. Importantly, integrated simulation can be used to reveal and solve the complexities of system integration that may otherwise not be apparent in physical components or models developed in isolation. New experimental test facilities that produce relevant conditions to validate and resolve key technical challenges for various subsystems (materials, blankets, fuel cycle, etc.) have been repeatedly called for by the fusion community but are not yet realized. Integrated modeling has an important role in identifying realistic load conditions (thermal, electromagnetic, plasma, neutron and photon loads, etc.) and defining the components and experiments for these test facilities in order to ensure meaningful validation that sufficiently reduces modeling uncertainties and technical risk for the full integrated reactor. The Fusion REactor Design and Assessment (FREDA) SciDAC project is building a component-based integrated modeling framework & data structure to enable self-consistent, multi-fidelity, iterative optimization workflows for the fusion reactor design process. FREDA aims to shorten the time to viable designs by providing a set of flexible workflows to support the various stages of the design process using an integrated model hierarchy, ranging from the simple analytic descriptions to the highest fidelity, theory-based plasma and engineering modeling developed by the fusion and fission communities. These tools are expected to be needed for timely support of FPP design in the milestone program and in the FIRE collaboratives. The plasma simulation backbone of FREDA is IPS-FASTRAN with newly developed coupled Core-Edge Pedestal-SOL (CESOL) workflows, which is being extended to the far-SOL region up to the plasma facing components. FREDA incorporates the FERMI engineering modeling suite and will enable self-consistent evaluation of the thermal shields, limiters, blanket, magnets, and other surrounding structures with predictions of temperatures, erosion, dpa, activation, tritium generation and transport, creep, corrosion, material degradation, etc. Parametric generation of 3D CAD enables rapid iteration of component geometry in response to plasma and loading specifications.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
NASA NTRS1985

Improved RF Isolation Amplifier

Circuit has high reverse isolation and wide bandwidth. Wideband isolation amplifier has low intermodulation distortion and high reverse isolation. Circuit does not require selected or matched components or directional coupling device. Circuit used in applications requiring high reverse isolation such as receiver intermediate-frequency (IF) strips and frequency distribution systems. Also applicable in RF and video signaling.

Stevens, G. L.↗
NASA NTRS1981

A Design Process for the Acoustical System of an Enclosed Space Colony

Sounds of Silence. Using a general systems approach, factors and components of the acoustical design process for an isolated, confined space community in a torus space enclosure are considered. These components include the following: organizational structure and its effect on alternatives; problem definition and limits; criteria and priorities; methods of data gathering; modelling and measurement of the whole system and its components; decision methods; and design scenario of the acoustics of the complex, socio-technical space community system with emphasis on the human factors.

Hawke, Joanne↗
DOE OSTI2023

Structure, Function, and Application of Self–Healing Adhesives from Mistletoe Viscin

Berries from the European Mistletoe (Viscum album) possess a sticky tissue called viscin that facilitates adhesion and germination onto host trees. Recent studies of viscin have demonstrated its adhesive capacity on a range of natural and synthetic surfaces including wood, skin, metals, and plastic. Yet, the underlying mechanisms remain poorly understood. Here, an investigation of the adhesive performance of mistletoe viscin is performed, demonstrating its hygroscopic nature and ability to self-heal following adhesive failure. It is identified that adhesion originates from a water-soluble adhesive component that can be extracted, isolated, and characterized independently. Lap shear mechanical testing indicates that the mistletoe adhesive extract (MAE) outperforms native viscin tissue, as well as gum arabic and arabinogalactan—common plant-based adhesives. Furthermore, humidity uptake experiments reveal that MAE can reversibly absorb nearly 100% of its mass in water from the atmosphere. In-depth spectroscopic and mass spectrometry investigations reveal a composition consisting primarily of an atypical arabinogalactan, with additional sugar alcohols. Finally, several proof-of-concept applications are demonstrated using MAE for hygro-responsive reversible adhesion between various surfaces including skin, plastic, PDMS, and paper, revealing that MAE holds potential as a biorenewable and reusable adhesive for applications in cosmetics, packaging, and potentially, tissue engineering.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Performance evaluations of signed and unsigned noisy approximate quantum Fourier arithmetic

The Quantum Fourier Transform (QFT) grants competitive advantages, especially in resource usage and circuit approximation, for performing arithmetic operations on quantum computers, and offers a potential route toward a numerical quantum-computational paradigm. In this paper, we utilize efficient techniques to implement QFT-based integer addition and multiplications. These operations are fundamental to various quantum applications including Shor’s algorithm, weighted-sum optimization problems in data processing and machine learning, and quantum algorithms requiring inner products. We carry out performance evaluations of these implementations based on IBM’s superconducting-qubit architecture using different compatible noise models. We isolate the sensitivity of the component quantum circuits on both one-/two-qubit gate error rates, and the number of the arithmetic operands’ superposed integer states. We analyze performance and identify the most effective approximation depths for unsigned quantum addition and quantum multiplication within the given context. We then perform a similar analysis of signed addition and compare to the unsigned results. We observe significant dependency of the optimal approximation depth on the degree of machine noise and the number of superposed states in certain performance regimes. Finally, we elaborate on the algorithmic challenges—relevant to signed, unsigned, modular and non-modular versions—that could also be applied to current implementations of QFT-based subtraction, division, exponentiation, and their potential tensor extensions. Here, we analyze the performance trends in our results and speculate on possible future developments within this computational paradigm.

Computational models↗
DOE OSTI2024

Analyzing the impact of design factors on solar module thermomechanical durability using interpretable machine learning techniques

Solar modules in utility-scale systems are expected to maintain decades of lifetime to rival conventional energy sources. However, cyclic thermomechanical loading often degrades their long-term performance, highlighting the importance of effective design to mitigate thermal expansion mismatches between module materials. Given the complex composition of solar modules, isolating the impact of individual components on overall durability remains a challenging task. In this work, we analyze a comprehensive data set that comprises bill-of-materials (BOM) and thermal cycling power loss from 251 distinct module designs to identify the predominant design factors and their impacts on the thermomechanical durability of modules. The methodology of our analysis combines machine learning modeling (random forest) and Shapley additive explanation (SHAP) to correlate design factors with power loss and interpret the model’s decision-making. The interpretation reveals that silicon type (monocrystalline or polycrystalline), encapsulant thickness, busbar numbers, and wafer thickness predominantly influence the degradation. With lower power loss of around 0.6% on average in the SHAP analysis, monocrystalline cells present better durability than polycrystalline cells. This finding is further substantiated by statistical testing on our raw data set. The SHAP analysis also demonstrates that while thicker encapsulants lead to reduced power loss, further increasing their thickness over around 0.6 to 0.7 mm does not yield additional benefits, particularly for the front side one. In addition, other important BOM features such as the number of busbars are analyzed. This study provides a blueprint for utilizing explainable machine learning techniques in a complex material system and can potentially guide future research on optimizing the design of solar modules.

14 SOLAR ENERGY↗
DOE OSTI2022

Performance Evaluations of Noisy Approximate Quantum Fourier Arithmetic

The Quantum Fourier Transform (QFT) grants competitive advantages, especially in resource usage and circuit approximation, for performing arithmetic operations on quantum computers, and offers a potential route towards a numerical quantum-computational paradigm. In this paper, we utilize efficient techniques to implement QFT-based integer addition and multiplications. These operations are fundamental to various quantum applications including Shor’s algorithm, weighted sum optimization problems in data processing and machine learning and quantum algorithms requiring inner products. We carry out performance evaluations of these implementations based on IBM’s superconducting qubit architecture using different compatible noise models. We isolate the sensitivity of the component quantum circuits on both one-/two-qubit gate error rates, and the number of the arithmetic operands’ superposed integer states. We analyze performance, and identify the most effective approximation depths for quantum add and quantum multiply within the given context. We observe significant dependency of the optimal approximation depth on the degree of machine noise and the number of superposed states in certain performance regimes. Finally, we elaborate on the algorithmic challenges - relevant to signed, unsigned, modular and non-modular versions - that could also be applied to current implementations of QFT-based subtraction, division, exponentiation, and their potential tensor extensions. Here, we analyze performance trends in our results and speculate on possible future development within this computational paradigm.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2023

Techno-Economic Case Study: Fermentation Cost Impacts from Selected Critical Material Attributes

This report summarizes analysis conducted to support a case study under the Feedstock-Conversion Interface Consortium (FCIC) focused on techno-economic analysis (TEA) modeling to quantify the economic implications of biomass hydrolysate substrate variability on fermentation performance and resultant biorefinery fuel yields. It is known that fermentation inhibitors or byproducts, as may either come from constituents in the biomass feedstock or imparted through biorefinery processing operations, can detrimentally impact fermentation rates and yields. However, it is often difficult to isolate fermentation impacts to individual components given the complex nature of biomass varying simultaneously in multiple attributes from one lot to another. For this study, we worked with FCIC researchers to obtain data on key fermentation performance metrics, namely productivity rates and conversion yields, across a number of material attribute species previously selected by the researchers as "critical" attributes which may be found in hydrolysate used as microbial carbon sources during fermentation. These data were run through TEA models to estimate resultant impacts on biorefinery economics, reported as minimum fuel selling price (MFSP). Overall, the trends in MFSP closely followed fuel yields, in turn tied to fermentation process yields and selectivity, with minimal economic impact from variations in fermentation productivity.

09 BIOMASS FUELS↗
DOE OSTI2021

Prediction of Detonation-Induced Disturbances Propagating Upstream into Inlets of Rotating Detonation Combustors

Disturbances caused by the detonation wave in a rotating detonation combustor (RDC) propagate upstream through the inlet, and can potentially affect and couple to upstream components, such as turbomachinery or isolators. These disturbances can potentially also affect the operation of the RDC itself. By drawing from the analogy of a detonation wave bounded by an inert gas, the pressure disturbances observed upstream of the inlet are explained as the consequence of the passage of an upstream propagating oblique shock. In this study, the pressure rise in the plenum from the oblique shock is measured in an axial air inlet RDC. The speed of the upstream propagating wave is estimated to be moderately above the acoustic speed of the oxidizer in the plenum. The wave propagates into the plenum despite local regions of choking in the inlet. It is estimated that the time it takes a fluid particle to transit from the plenum to the detonation channel through the inlet is much larger than the rotational time of the detonation wave. This implies that a fluid particle experiences multiple shocks prior to entering the detonation channel. The oblique shock propagating upstream through the inlet area change is modeled by leveraging an analogy with a quasi-1D shock wave moving in a variable area duct with mean (incoming) flow. Due to flow expansion along the area change, fluid particles are found to experience stronger shocks in the inlet than in the plenum, thereby creating different thermodynamic states within the fill region as the oxidizer emerges from the inlet.

Feleo, Alexander↗
NASA NTRS1969

Proceedings of the Second Workshop on Voltage Breakdown in Electronic Equipment at Low Air Pressure

The Second Workshop on Voltage Breakdown in Electronic Equipment at Low Air Pressure was sponsored by the Jet Propulsion Laboratory, Pasadena, California. It has been three and one-half years since the convening of the first workshop on voltage breakdown. In this interval, gains are evidenced in the progress and sophistication in solving voltage breakdown problems affecting electronic equip­ment operating at high altitudes or other low air pressure environments. Although space applications predominate the area of concern, other projects such as the SST are becoming increasingly involved with voltage breakdown. High-voltage breakdown in spacecraft continues; however, the incidences of occurrence appear to have decreased in spite of an increase in the number of missions flown. This, it is felt, is due to many project managers now requiring all equipment with voltage in excess of 270-V peak to be designed to operate in the critical pressure region without damage, even though its normal functional environment is sea level pressure and the hard vacuum of space. In addition, designers are becoming more aware of the principle of good high-voltage design by selecting void-free components, proper spacing of conductors, isolating high-­voltage circuitry from lower voltage areas, etc. The consensus seems to be that the slight increase in cost to achieve a provable corona-free design is more than offset by the increase in confidence that the equipment will survive accidental loss of vacuum during high-vacuum tests, inadvertent turn on while passing through the critical air-pressure region of earth after launch or outgassing in flight pressurizing the enclosure into the critical pressure region.

E. R. Bunker, Jr.↗
NASA NTRS1979

Hg ion thruster component testing

Electron bombardment thrusters, under development to provide both auxiliary and primary propulsion functions for a large variety of space missions are tested. Thruster design verification which requires life tests of durations of the order of the time anticipated in space applications, are discussed. The life time and reliability of an electron bombardment thruster is dependent upon the performance of several critical components including cathodes, vaporizers, and isolators. The performances of the cathode, vaporizer, and propellant isolaters during fatigue analyses are examined.

Mantenieks, M. A.↗
NASA NTRS1980

Transonic Flow Field Analysis for Wing-Fuselage Configurations

A computational method for simulating the aerodynamics of wing-fuselage configurations at transonic speeds is developed. The finite difference scheme is characterized by a multiple embedded mesh system coupled with a modified or extended small disturbance flow equation. This approach permits a high degree of computational resolution in addition to coordinate system flexibility for treating complex realistic aircraft shapes. To augment the analysis method and permit applications to a wide range of practical engineering design problems, an arbitrary fuselage geometry modeling system is incorporated as well as methodology for computing wing viscous effects. Configuration drag is broken down into its friction, wave, and lift induced components. Typical computed results for isolated bodies, isolated wings, and wing-body combinations are presented. The results are correlated with experimental data. A computer code which employs this methodology is described.

Boppe, C. W.↗