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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 775 records · Page 43
All sourcesNASA NTRSDOE OSTI
NASA NTRS2000

Gravitational Effects on Combustion Synthesis of Advanced Porous Materials

Combustion Synthesis (self-Propagating high-temperature synthesis-(SHS)) of porous Ti-TiB(x), composite materials has been studied with respect to the sensitivity to the SHS reaction parameters of stoichiometry, green density, gasifying agents, ambient pressure, diluents and gravity. The main objective of this research program is to engineer the required porosity and mechanical properties into the composite materials to meet the requirements of a consumer, such as for the application of bone replacement materials. Gravity serves to restrict the gas expansion and the liquid movement during SHS reaction. As a result, gravitational forces affect the microstructure and properties of the SHS products. Reacting these SHS systems in low gravity in the KC-135 aircraft has extended the ability to form porous products. This paper will emphasize the effects of gravity (low g, 1g and 2g) on the SHS reaction process, and the microstructure and properties of the porous composite. Some of biomedical results are also discussed.

Zhang, X.↗
DOE OSTI2014

Constructing Hardware in a Scale Embedded Language

Chisel is a new open-source hardware construction language developed at UC Berkeley that supports advanced hardware design using highly parameterized generators and layered domain-specific hardware languages. Chisel is embedded in the Scala programming language, which raises the level of hardware design abstraction by providing concepts including object orientation, functional programming, parameterized types, and type inference. From the same source, Chisel can generate a high-speed C++-based cycle-accurate software simulator, or low-level Verilog designed to pass on to standard ASIC or FPGA tools for synthesis and place and route.

Bachan, John↗
DOE OSTI2014

Exposure to low doses of formaldehyde during pregnancy suppresses the development of allergic lung inflammation in offspring

Formaldehyde (FA) is an environmental and occupational pollutant, and its toxic effects on the immune system have been shown. Nevertheless, no data are available regarding the programming mechanisms after FA exposure and its repercussions for the immune systems of offspring. In this study, our objective was to investigate the effects of low-dose exposure of FA on pregnant rats and its repercussion for the development of allergic lung inflammation in offspring. Pregnant Wistar rats were assigned in 3 groups: P (rats exposed to FA (0.75 ppm, 1 h/day, 5 days/week, for 21 days)), C (rats exposed to vehicle of FA (distillated water)) and B (rats non-manipulated). After 30 days of age, the offspring was sensitised with ovalbumin (OVA)-alum and challenged with aerosolized OVA (1%, 15 min, 3 days). After 24 h the OVA challenge the parameters were evaluated. Our data showed that low-dose exposure to FA during pregnancy induced low birth weight and suppressed the development of allergic lung inflammation and tracheal hyperresponsiveness in offspring by mechanisms mediated by reduced anaphylactic antibodies synthesis, IL-6 and TNF-alpha secretion. Elevated levels of IL-10 were found. Any systemic alteration was detected in the exposed pregnant rats, although oxidative stress in the uterine environment was evident at the moment of the delivery based on elevated COX-1 expression and reduced cNOS and SOD-2 in the uterus. Therefore, we show the putative programming mechanisms induced by FA on the immune system for the first time and the mechanisms involved may be related to oxidative stress in the foetal microenvironment. - Highlights: • Formaldehyde exposure does not cause lung inflammation in pregnant rats. • Formaldehyde exposure suppresses allergic lung inflammation in the offspring. • Formaldehyde exposure induces oxidative stress in uterine environment.

60 APPLIED LIFE SCIENCES↗
NASA NTRS1988

Early quantitative method for measuring germination in non-green spores of Dryopteris paleacea using an epifluorescence-microscope technique

A method is described to determine germination by blue-light excited red fluorescence in the positively photoblastic spores of Dryopteris paleacea Sw. This fluorescence is due to chlorophyll as evidenced from 1) a fluorescence-emission spectrum in vivo, where a bright fluorescence around 675 nm is obtained only in red light (R)-irradiated spores and 2) in vitro measurements with acetone extracts prepared from homogenized spores. Significant amounts of chlorophyll can be found only in R-treated spores; this chlorophyll exhibits an emission band around 668 nm, when irradiated with 430 nm light at 21 degrees C. Compared to other criteria for germination, such as swelling of the cell, coat splitting, greening, and rhizoid formation, which require longer periods after induction for their expression, chlorophyll fluorescence can be used to quantify germination after two days. This result is confirmed by fluence-response curves for R-induced spore germination; the same relationship between applied R and germination is obtained by the evaluation with the epifluorescence method 2 days after the light treatment as compared with the evaluation with bright-field microscopy 5 days after the inducing R. Using this technique we show for the first time that Ca2+ contributes to the signal-transduction chain in phytochrome-mediated chlorophyll synthesis in spores of Dryopteris paleacea.

NASA Discipline Plant Biology↗
NASA NTRS1992

Nonenzymatic template-directed synthesis on hairpin oligonucleotides. 3. Incorporation of adenosine and uridine residues

We have used [32P]-labeled hairpin oligonucleotides to study template-directed synthesis on templates containing one or more A or T residues within a run of C residues. When nucleoside-5'-phosphoro(2-methyl)imidazolides are used as substrates, isolated A and T residues function efficiently in facilitating the incorporation of U and A, respectively. The reactions are regiospecific, producing mainly 3'-5'-phosphodiester bonds. Pairs of consecutive non-C residues are copied much less efficiently. Limited synthesis of CA and AC sequences on templates containing TG and GT sequences was observed along with some synthesis of the AA sequences on templates containing TT sequences. The other dimer sequences investigated, AA, AG, GA, TA, and AT, could not be copied. If A is absent from the reaction mixture, misincorporation of G residues is a significant reaction on templates containing an isolated T residue or two consecutive T residues. However, if both A and G are present, A is incorporated to a much greater extent than G. We believe that wobble-pairing between T and G is responsible for misincorporation when only G is present.

NASA Discipline Number 52-20↗
NASA NTRS1992

Nonenzymatic template-directed synthesis on hairpin oligonucleotides. 2. Templates containing cytidine and guanosine residues

We have prepared hairpin oligonucleotides in which a 5'-terminal single-stranded segment contains cytidylate (C) and guanylate (G) residues. When these hairpin substrates are incubated with a mixture of cytidine 5'-phosphoro(2-methly)imidazolide (2-MeImpC) and guanosine 5'-phosphoro(2-methyl)imidazolide (2-MeImpG), the 5'-terminal segment acts as a template to facilitate sequence-specific addition of G and C residues to the 3'-terminus of the hairpin. If an isolated G residue is present at the 3'-end of the template strand, it is copied regiospecifically in the presence of 2-MeImpC and 2-MeImpG to give a product containing an isolated C residue linked to its G neighbors by 3'-5'-internucleotide bonds. However, if only 2-MeImpC is present in the reaction mixture, very little reaction occurs. Thus, the presence of 2-MeImpG catalyzes the incorporation of C. If the template strand contains a short sequence of G residues, it is copied in the presence of a mixture of 2-MeImpC and 2-MeImpG. If only 2-MeImpC is present in the reaction mixture, efficient synthesis occurs to give a final product containing one fewer C residue than the number of G residues in the template.

NASA Program Exobiology↗
DOE OSTI2024

Convergence QL: NSF/DOE Quantum Science Summer School: QS3 Final Report

Convergence QL: NSF/DOE Quantum Science Summer School (QS3) was a 2-week summer program held in 2017, 2018, 2019, and 2022. The program was aimed at graduate students and postdoctoral researchers working on a wide range of topics related to quantum science and quantum engineering. Expert leaders in this field served as lectures for the school. The school program included lectures, active learning, project activities, poster presentations, and industry panel discussions. The school covered four topics: Fundamentals and Applications of Quantum Computing (2017), Fundamentals and Applications of Quantum Materials (2018), Fundamentals and Applications of Quantum Devices (2019), and Modern Synthesis of Quantum Materials (2022). In terms of intellectual merit, the school brought together students from different areas of research related to quantum science to educate them on a broad range of related topics, providing a unique crucible for the development of educational content and learning opportunities in a cross-disciplinary fashion in the context of quantum science and quantum engineering. In terms of broader impacts, this may serve to create a workforce which would accelerate research in quantum science, quantum engineering, and the development of new quantum technologies beneficial to society. Additionally, this may add to the training of a cadre of scientists and engineers to serve as future leaders in this research field.

42 ENGINEERING↗
NASA NTRS1982

Space environment and lunar surface processes, 2

The top few millimeters of a surface exposed to space represents a physically and chemically active zone with properties different from those of a surface in the environment of a planetary atmosphere. To meet the need or a quantitative synthesis of the various processes contributing to the evolution of surfaces of the Moon, Mercury, the asteroids, and similar bodies, (exposure to solar wind, solar flare particles, galactic cosmic rays, heating from solar radiation, and meteoroid bombardment), the MESS 2 computer program was developed. This program differs from earlier work in that the surface processes are broken down as a function of size scale and treated in three dimensions with good resolution on each scale. The results obtained apply to the development of soil near the surface and is based on lunar conditions. Parameters can be adjusted to describe asteroid regoliths and other space-related bodies.

Comstock, G. M.↗
NASA NTRS1991

IMPAC: An Integrated Methodology for Propulsion and Airframe Control

The National Aeronautics and Space Administration is actively involved in the development of enabling technologies that will lead towards aircraft with new/enhanced maneuver capabilities such as Short Take-Off Vertical Landing (STOVL) and high angle of attack performance. Because of the high degree of dynamic coupling between the airframe and propulsion systems of these types of aircraft, one key technology is the integration of the flight and propulsion control. The NASA Lewis Research Center approach to developing Integrated Flight Propulsion Control (IFPC) technologies is an in-house research program referred to as IMPAC (Integrated Methodology for Propulsion and Airframe Control). The goals of IMPAC are to develop a viable alternative to the existing integrated control design methodologies that will allow for improved system performance and simplicity of control law synthesis and implementation, and to demonstrate the applicability of the methodology to a supersonic STOVL fighter aircraft. Based on some preliminary control design studies that included evaluation of the existing methodologies, the IFPC design methodology that is emerging at the Lewis Research Center consists of considering the airframe and propulsion system as one integrated system for an initial centralized controller design and then partitioning the centralized controller into separate airframe and propulsion system subcontrollers to ease implementation and to set meaningful design requirements for detailed subsystem control design and evaluation. An overview of IMPAC is provided and detailed discussion of the various important design and evaluation steps in the methodology are included.

Garg, Sanjay↗
NASA NTRSDate not supplied

The Atmosphere Observing System (AOS): Synergistic Aerosol, Cloud, Convection and Precipitation Measurement and Modeling Systems

The 2017 Decadal Survey (DS) highlighted Earth System Science themes, science and application questions, and several high priority objectives that have led to the inclusion of Aerosols (A) and Clouds-Convection-Precipitation (CCP) as Designated Observables (DOs). On June 1, 2018, several NASA centers (GSFC, LaRC, JPL, MSFC, GRC and ARC) submitted a joint Study Plan to the NASA Earth Science Division for the Aerosol (A) and Cloud, Convection, and Precipitation (CCP) Pre-formulation Study (ACCP), with the ACCP Study concluding in early 2021. The new mission now in pre-phase A is being referred to as the Atmosphere Observing System (AOS), an integral part of NASA’s Earth System Observatory (ESO) strategy. The DS and the ACCP team recognized the science merit in combining the A and CCP DOs for both enhancing the ability to address a number of science objectives and also to provide an expanded capability to address additional objectives beyond those of the individual DOs. A critical element of the ACCP observing strategy is to make extensive use of new passive and active sensors as well as of the so-called Program-of-Record (PoR), complemented by a fully integrated sub-orbital component. In order to achieve maximum benefit, all these observations need to be integrated into comprehensive observing and modeling/data assimilation systems. Such an approach requires comprehensive model-data synthesis capabilities that needs to be conceived in conjunction with the space-based and suborbital components of AOS. In this presentation we will summarize the major science goals of AOS including cloud feedbacks, atmospheric convection, emphasizing aerosol processes and aerosol radiative effects, and the synergistic aspects of clouds-precipitation-aerosol interactions. We will describe examples of how AOS data will be used across space and time to better initialize forecasts and train modeling systems, and to infuse models and data assimilation systems with AOS data for advancing operational predictions and to generate expanded hindcasts and reconstruction of the climate record.

Arlindo da Silva↗
NASA NTRS1979

Phase 1 of the near term hybrid passenger vehicle development program, appendix A. Mission analysis and performance specification studies. Volume 2: Appendices

A handy reference for JPL minimum requirements and guidelines is presented as well as information on the use of the fundamental information source represented by the Nationwide Personal Transportation Survey. Data on U.S. demographic statistics and highway speeds are included along with methodology for normal parameters evaluation, synthesis of daily distance distributions, and projection of car ownership distributions. The synthesis of tentative mission quantification results, of intermediate mission quantification results, and of mission quantification parameters are considered and 1985 in place fleet fuel economy data are included.

Traversi, M.↗
DOE OSTI2019

A generalized superstructure-based framework for process synthesis

We propose a general framework for the formulation of superstructure-based optimization models for holistic process synthesis. First, we redefine the fundamental problems of reactor, separation, and heat exchanger network synthesis, by presenting generalized problem statements, to make them amenable to seamless integration with each other. Second, we describe the general forms of models that can be developed to address these generalized problems and identify some key characteristics. Notably, for each system, we identify internal variables used only within the system, cost variables used in the objective function, and, importantly, coupling variables for the coupling between systems. Third, we outline some literature models that can be used to address the generalized problems and present new models to couple the three systems. Finally, we show how the individual components (systems and coupling models) can be integrated to formulate a single simultaneous reactor, separation, and heat exchanger network synthesis.

97 MATHEMATICS AND COMPUTING↗
NASA NTRS1980

Applications of SLAR in nuclear power plant siting: A case history

Over 10,000 square km of side-looking airborne radar (SLAR) imagery was obtained and analyzed for the siting of the first nuclear power plant in the Republic of the Philippines. The imagery was obtained using the Motorola APS/AN-94D (X-band) real aperture system as part of an overall remote sensing program to site and evaluate potential site regions. Analysis of SLAR images, in conjunction with LANDSAT, color, black and white, and thermal infrared images, provided basic information on structure, relative geochronology, stratigraphy, geomorphology, and ground water, which facilitated field operations and data synthesis.

Siegal, B. S.↗
NASA NTRS1986

EOS radiometer concepts for soil moisture remote sensing

Preliminary work with aperture synthesis concepts for EOS is reported. The effects of nonvanishing bandwidths on image reconstruction in aperture synthesis system was studied. It is found that nonvanishing bandwidths introduce errors in off-axis pixels when naive Fourier processing is used. The net effect is for bandwidth to limit sensor field-of-view. To quantify this effect a computer program was written which is documented. Example runs are included which illustrate the resultant radiometric errors and effective fields-of-view for a plausible simple sensor.

Carr, J.↗
NASA NTRS1991

IMPAC - An integrated methodology for propulsion and airframe control

The NASA Lewis Research Center approach to developing integrated flight propulsion control (IFPC) technologies is an in-house research program referred to as IMPAC-Integrated Methodology for Propulsion and Airframe Control. The goals of IMPAC are to develop a viable alternative to the existing integrated control design methodologies that will allow for improved system performance and simplicity of control law synthesis and implementation, and to demonstrate the applicability of the methodology to a supersonic STOVL fighter aircraft. An overview of IMPAC is presented, including a detailed discussion of the various important design and evaluation steps in the methodology.

Garg, Sanjay↗
NASA NTRS1996

Momentum Transfer Studies and Studies of Linear and Nonlinear Optical Properties of Metal Colloids and Semiconductor Quantum Dots

Phase 1 of this work involved design work on a momentum transfer device. The progress on design and testing will be presented. Phase 2 involved the systematic study of the MPD thruster for dual uses. Though it was designed as a thruster for space vehicles, the characteristics of the plasma make it an excellent candidate for industrial applications. This project sought to characterize the system for use in materials processing and characterization. The surface modification on ZnCdTe, CdTe, and ZnTe will be presented. Phase 3 involved metal colloids and semiconductor quantum dots. One aspect of this project involves a collaborative effort with the Solid State Division of ORNL. The thrust behind this research is to develop ion implantation for synthesizing novel materials (quantum dots wires and wells, and metal colloids) for applications in all optical switching devices, up conversion, and the synthesis of novel refractory materials. The ions of interest are Au, Ag, Cd, Se, In, P, Sb, Ga, and As. The specific materials of interest are: CdSe, CdTe, InAs, GaAs, InP, GaP, InSb, GaSb, and InGaAs. A second aspect of this research program involves using porous glass (25-200 A) for fabricating materials of finite size. The results of some of this work will also be reported.

Collins, W. E.↗
NASA NTRS1993

Prebiotic syntheses of vitamin coenzymes: I. Cysteamine and 2-mercaptoethanesulfonic acid (coenzyme M)

The reaction of NH3 and SO3(2-) with ethylene sulfide is shown to be a prebiotic synthesis of cysteamine and 2-mercaptoethanesulfonic acid (coenzyme M). A similar reaction with ethylene imine would give cysteamine and taurine. Ethylene oxide would react with NH3 and N(CH3)3 to give the phospholipid components ethanolamine and choline. The prebiotic sources of ethylene sulfide, ethylene imine and ethylene oxide are discussed. Cysteamine itself is not a suitable thioester for metabolic processes because of acyl transfer to the amino group, but this can be prevented by using an amide of cysteamine. The use of cysteamine in coenzyme A may have been due to its prebiotic abundance. The facile prebiotic synthesis of both cysteamine and coenzyme M suggests that they were involved in very early metabolic pathways.

NASA Discipline Number 52-20↗
DOE OSTI2021

Ion Mobility Spectrometry Characterization of the Intermediate Hydrogen-Containing Gold Cluster Au7(PPh3)7H52+

We employ ion mobility spectrometry and density functional theory to determine the structure of Au7(PPh3)7H52+ (PPh3 = triphenylphosphine) which was recently identified by high mass resolution mass spectrometry. Experimental ion-neutral collision cross sections represent the momentum transfer between the ionic clusters and gas molecules averaged over the relative thermal velocities of the colliding pair, thereby providing structural insights. Theoretical calculations indicate the geometry of Au7(PPh3)7H52+ is similar to Au7(PPh3)7+, with three hydrogen atoms bridging two gold atoms and two hydrogen atoms forming single Au–H bonds. Collision induced dissociation products observed during IMS experiments reveal that smaller hydrogen containing clusters may be produced through fragmentation of Au7(PPh3)7H52+. Our findings indicate that hydrogen containing species like Au7(PPh3)7H52+ act as intermediates in the formation of larger phosphine ligated gold clusters. These results advance the understanding and ability to control the mechanisms of size selective cluster formation which is necessary for scalable synthesis of clusters with tailored properties. This work was supported by the U.S. Department of Energy (DOE), Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences, and Biosciences. M.A.H. acknowledges support from the DOE Science Undergraduate Laboratory Internship (SULI) program. H.H. acknowledges support from the DOE Office of Workforce Development for Teachers and Scientist (WDTS) under the Visiting Faculty Program (VFP). The efforts of K.A.M. and B.H.C. were supported by the Defense Threat Reduction Agency (Grant No. HDTRA1-14-1-0023). The research was performed using EMSL, a national scientific user facility sponsored by the DOE’s Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory (PNNL). PNNL is operated by Battelle for DOE under Contract DE-AC05-76RL01830.

Ligare, Marshall R.↗