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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 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS2003

Organics Synthesized Using Iron-Grain Silicates

We use Fischer-Tropsch type (FTT) synthesis to produce hydrocarbons by hydrogenating carbon monoxide via catalytic reactions. The products of these reactions have been studied using 'natural' catalysts and calculations of the efficiency of FTT synthesis in the Solar Nebula suggest that these types of reactions could make significant contributions to the composition of material near three AU. We coat Fe-silicate grains with organic material using FTT synthesis to simulate the chemistry in the early Solar Nebula. In our experimental setup, we roughly model a nebular environment where grains are successively transported from hot to cold regions of the nebula. In other words, the starting gases and FTT products are continuously circulated through the grains at high temperature with intervals of cooling. Organics generated in this manner could represent the carbonaceous material incorporated in comets and meteorites. We analyze the resulting organics and present the results.

Johnson, N. M.↗
NASA NTRS2004

Organics on Fe-Silicate Grains: Potential Mimicry of Meteoritic Processes?

Currently, it is unknown what exact process or combination of processes produced organics that are found in meteorites or are detected in comets and nebulas. One particular process that forms organics involves Fischer-Tropsch type (FTT) reactions. Fischer-Tropsch type reactions produce hydrocarbons by hydrogenating carbon monoxide via catalytic reactions. The overall reaction is shown. The products of these reactions have been studied using natural catalysts and calculations of the efficiency of FTT synthesis in the Solar Nebula suggest that these types of reactions could make significant contributions to the composition of material near three AU. We use FTT synthesis to coat amorphous Fesilicate grains with organic material to simulate the chemistry in the early Solar Nebula. We used lab-synthesized amorphous Fe-silicate grains for the catalyst because they might better simulate the starting materials found in protostellar nebulas. A brief description of the synthesis of these grains is given in Experiments. This work is different from previous studies because we focus here on the carbonaceous material deposited on the grains. In our experiments, we roughly simulate a model of the nebular environment where grains are successively transported from hot to cold regions of the nebula. In other words, the starting cold regions of the nebula. In other words, the starting gases and FTT products are continuously circulated through the grains at high temperature with intervals of cooling. Overall, organics generated in this manner could represent the carbonaceous material incorporated into comets and meteorites. We present the analyses of the organics produced using pyrolysis gas chromatography mass spectrometry (GCMS) and compare the results with those organics found in the Murchison meteorite.

Johnson, N. M.↗
NASA NTRS2003

A First Attempt to Simulate the Natural Formation of Meteoritic Organics

Our working hypothesis in these experiments is that meteoritic organics are a mixture of materials made both in the interstellar medium and in the solar nebula that were further processed within meteorite parent bodies to produce what we see today. The material synthesized in the pre-solar environment is currently under study in several laboratories, though to our knowledge none are investigating the changes that might occur as the result of metamorphic processes on the parent body itself. Material made in the Solar Nebula results from a Fischer-Tropsch type (FTT) synthesis as CO and H2 react on grain surfaces to make methane, as well as more complex species. The products of these reactions using natural catalysts have been well-studied and a calculation of the potential efficiency of FTT reactions in the solar nebula demonstrates that they could contribute significantly to the composition of material near 3 AU.

Gardner, Kathryn↗
NASA NTRS2014

Organic Analysis of Catalytic Fischer-Tropsch Synthesis Products and Ordinary Chondrite Meteorites by Stepwise Pyrolysis-GCMS: Organics in the Early Solar Nebula

Abiotic generation of complex organic compounds, in the early solar nebula that formed our solar system, is hypothesized by some to occur via Fischer-Tropsch (FT) synthesis. In its simplest form, FT synthesis involves the low temperature (<300degC) catalytic reaction of hydrogen and carbon monoxide gases to form more complex hydrocarbon compounds, primarily n-alkanes, via reactive nano-particulate iron, nickel, or cobalt, for example. Industrially, this type of synthesis has been utilized in the gas-to-liquid process to convert syngas, produced from coal, natural gas, or biomass, into paraffin waxes that can be cracked to produce liquid diesel fuels. In general, the effect of increasing reaction temperature (>300degC) produces FT products that include lesser amounts of n-alkanes and greater alkene, alcohol, and polycyclic aromatic hydrocarbon (PAH) compounds. We have begun to experimentally investigate FT synthesis in the context of abiotic generation of organic compounds in the early solar nebula. It is generally thought that the early solar nebula included abundant hydrogen and carbon monoxide gases and nano-particulate matter such as iron and metal silicates that could have catalyzed the FT reaction. The effect of FT reaction temperature, catalyst type, and experiment duration on the resulting products is being investigated. These solid organic products are analyzed by thermal-stepwise pyrolysis-GCMS and yield the types and distribution of hydrocarbon compounds released as a function of temperature. We show how the FT products vary by reaction temperature, catalyst type, and experimental duration and compare these products to organic compounds found to be indigenous to ordinary chondrite meteorites. We hypothesize that the origin of organics in some chondritic meteorites, that represent an aggregation of materials from the early solar system, may at least in part be from FT synthesis that occurred in the early solar nebula.

Locke, Darren R.↗
NASA NTRS2004

Electric Current Activated Combustion Synthesis and Chemical Ovens Under Terrestrial and Reduced Gravity Conditions

Combustion synthesis (CS) generally involves mixing reactants together (e.g., metal powders) and igniting the mixture. Typically, a reaction wave will pass through the sample. In field activated combustion synthesis (FACS), the addition of an electric field has a marked effect on the dynamics of wave propagation and on the nature, composition, and homogeneity of the product as well as capillary flow, mass-transport in porous media, and Marangoni flows, which are influenced by gravity. The objective is to understand the role of an electric field in CS reactions under conditions where gravity-related effects are suppressed or altered. The systems being studied are Ti+Al and Ti+3Al. Two different ignition orientations have been used to observe effects of gravity when one of the reactants becomes molten. This consequentially influences the position and concentration of the electric current, which in turn influences the entire process. Experiments have also been performed in microgravity conditions. This process has been named Microgravity Field Activated Combustion Synthesis (MFACS). Effects of gravity have been demonstrated, where the reaction wave temperature and velocity demonstrate considerable differences besides the changes of combustion mechanisms with the different high currents applied. Also the threshold for the formation of a stable reaction wave is increased under zero gravity conditions. Electric current was also utilized with a chemical oven technique, where inserts of aluminum with minute amounts of tungsten and tantalum were used to allow observation of effects of settling of the higher density solid particles in liquid aluminum at the present temperature profile and wave velocity of the reaction.

Unuvar, C.↗
NASA NTRS2022

Organic synthesis associated with serpentinization and carbonation on early Mars

Water-rock interactions are relevant to planetary habitability, influencing mineralogical diversity and the production of organic molecules. We examine carbonates and silicates in the Martian meteorite Allan Hills 84001 (ALH 84001), using co-located nano-scale analyses, to characterize the nature of water-rock reactions on early Mars. We find complex refractory organic material associated with mineral assemblages that formed by mineral carbonation and serpentinization reactions. The organic molecules are co-located with nanophase magnetite; both formed in situ during water-rock interactions on Mars. Two potentially distinct mechanisms of abiotic organic synthesis operated on early Mars during the late Noachian period (3.9–4.1 Ga).

A. Steele↗
NASA NTRS1979

Demand and supply of hydrogen as chemical feedstock in USA

Projections are made for the demand and supply of hydrogen as chemical feedstock in USA. Industrial sectors considered are petroleum refining, ammonia synthesis, methanol production, isocyanate manufacture, edible oil processing, coal liquefaction, fuel cell electricity generation, and direct iron reduction. Presently, almost all the hydrogen required is produced by reforming of natural gas or petroleum fractions. Specific needs and emphases are recommended for future research and development to produce hydrogen from other sources to meet the requirements of these industrial sectors. The data and the recommendations summarized in this paper are based on the Workshop 'Supply and Demand of Hydrogen as Chemical Feedstock' held at the University of Houston on December 12-14, 1977.

Huang, C. J.↗
NASA NTRS2014

De Novo Synthesis and Functional Study of Primitive Polypeptides in the Prebiotic Protein World

DNA, RNA and proteins within a lipid-bound membrane are the core components of life, but the order of their appearance during the origin of life is still under debate. The widely accepted RNA World hypothesis states that RNA likely emerged prior to proteins and DNA since RNA can serve both replicative and catalytic roles. While biochemists have reproduced the synthesis, polymerization, and replication of nucleotides and RNA under controlled prebiotic conditions, it is clear that such complex organic molecules were are not present in significant amounts in the the starting prebiotic material on Earth either from endogenous production or meteoritic input. In contrast, amino acids are naturally abundant in various prebiotic contexts such as carbonaceous chondrites and Urey-Miller type experiments, and many studies have demonstrated that under plausible prebiotic conditions amino acids could condense or polymerize to give rise to short peptides. These findings support the basis of a Protein World hypothesis for life, however little has been done to study the functions of such primitive peptides. Here we present our novel synthetic biology-based approach to the de novo synthesis of billions of primitive peptidesproteins derived from a limited set of naturally abundant proteinogenic amino acids such as glycine, alanine, aspartic acid, glutamic acid, valine and serine. Of these peptides, the ones with divalent metal-binding capability are of particular interest and will be screened and identified. Certain divalent metals were likely present in prebiotic environments. Not only do they coordinate well with amino acids, but they also catalyze reactions, which are difficult to achieve in organic chemistry. Since D-chiral and non-proteinogenic amino acids are also abundant in the universe and may provide insight into the pathway by which life developed, we will also discuss methods to analyze primitive peptides consisting of these amino acids and D-chiral and non-proteinogenic amino acids. By understanding this naturalistic pathway, we will be able to better understand how life developed here on Earth. Since these amino acids are abundant in universe, this work provide insight into pathways by which life developed on Earth and, by extension, the probability of life arising elsewhere.

Fujishima, Kosuke↗
NASA NTRS2003

Hydrogen Purification Using Natural Zeolite Membranes

The School of Science at Universidad del Turabo (UT) have a long-lasting investigation plan to study the hydrogen cleaning and purification technologies. We proposed a research project for the synthesis, phase analysis and porosity characterization of zeolite based ceramic perm-selective membranes for hydrogen cleaning to support NASA's commitment to achieving a broad-based research capability focusing on aerospace-related issues. The present study will focus on technology transfer by utilizing inorganic membranes for production of ultra-clean hydrogen for application in combustion. We tested three different natural zeolite membranes (different particle size at different temperatures and time of exposure). Our results show that the membranes exposured at 900 C for 1Hr has the most higher permeation capacity, indicated that our zeolite membranes has the capacity to permeate hydrogen.

DelValle, William↗
NASA NTRS1991

Electrical energy sources for organic synthesis on the early earth

It is pointed out that much of the contemporary origin-of-life research uses the original estimates of Miller and Urey (1959) for terrestrial energy dissipation by lightning and coronal discharges being equal to 2 x 10 to the 19th J/yr and 6 x 10 to the 19th J/yr, respectively. However, data from experiments that provide analogues to naturally-occurring lightning and coronal discharges indicate that lightning energy yields for organic synthesis (nmole/J) are about one order of magnitude higher than the coronal discharge yields. This suggests that, on early earth, organic production by lightning may have dominated that due to coronal emission. New values are recommended for lightning and coronal discharge dissipation rates on the early earth, 1 x 10 to the 18th J/yr and 5 x 10 to the 17th J/yr, respectively.

Chyba, Christopher↗
NASA NTRS1993

Control of cell cycle by metabolites of prostaglandin D2 through a non-cAMP mediated mechanism

The dehydration products of PGD2, 9-deoxy-9 prostaglandin D2(PGJ2), 9-deoxy-delta 9, delta 12, delta 13 dehydroprostaglandin D2 (delta 12 PGJ2), and PGA2 all contain an unsaturated cyclopentenone structure which is characteristic of prostaglandins which effectively inhibit cell growth. It has been suggested that the action of the inhibitory prostaglandins may be through a cAMP mechanism. In this study, we use S49 wild type (WT) and adenylate cyclase variant (cyc-) cells to show that PGD2 and PGJ2 are not acting via a cyclic AMP mechanism. First, the increase in cyclic AMP in wild type S-49 cells is not proportional to its effects on DNA synthesis. More importantly, when S-49 cyc- cells were exposed to PGJ2, the adenylate cyclase (cyc-) mutant had decreased DNA synthesis with no change in its nominal cAMP content. Short-term (2 hours or less) exposure of the cyc- cells to prostaglandin J2 caused an inhibition of DNA synthesis. PGJ2 caused cytolysis at high concentrations. Long-term exposure (>14 hrs) of the cells to PGJ2, delta 12PGJ2 or delta 12, delta 14PGJ2 caused a cell cycle arrest in G1 demonstrating a cell cycle specific mechanism of action for growth inhibition by naturally occurring biological products independent of cAMP.

NASA Discipline Cell Biology↗
NASA NTRS1976

Solar cell array design handbook, volume 1

Twelve chapters discuss the following: historical developments, the environment and its effects, solar cells, solar cell filters and covers, solar cell and other electrical interconnections, blocking and shunt diodes, substrates and deployment mechanisms, material properties, design synthesis and optimization, design analysis, procurement, production and cost aspects, evaluation and test, orbital performance, and illustrative design examples. A comprehensive index permits rapid locating of desired topics. The handbook consists of two volumes: Volume 1 is of an expository nature while Volume 2 contains detailed design data in an appendix-like fashion. Volume 2 includes solar cell performance data, applicable unit conversion factors and physical constants, and mechanical, electrical, thermal optical, magnetic, and outgassing material properties. Extensive references are provided.

Rauschenbach, H. S.↗
NASA NTRSDate not supplied

Additional Trials & Tribulations in Synthesizing a Sulfide Standard

Well-characterized sulfide reference materials that can serve as matrix-matched calibrants for in-situ trace element analyses via laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) remain elusive. Here, we describe the creation an in-house sulfide standard at NASA JSC that will be used to measure siderophile and chalcophile trace elements in low pressure experimental products, specifically pentlandite ([FeNi]9S8) and pyrrhotite ([FeNi]1-xS), as well as natural sulfides in terrestrial and meteoritic mineral assemblages. Recent methods in creating a homogenous sulfide standard include pressed pellets, synthesized chips, or fused glass [e.g. 1-3]. Other studies, however, have had success in forming homogenous FeS standards via synthesization methods [e.g. 4-6]. We present a variation of the method described in [4], in which we create a pyrrhotite standard doped with a variety of trace elements (Zn, As, Se, Mo, Ru, Rh, Pd, Sn, Sb, Te, W, Os, Ir, Pt, Au) at ~10-40 ppm and Cu at ~200 ppm. Sulfide compositions were constructed using Fe and Ni metal and elemental sulfur powders. Trace elements were added to elemental sulfur from Atomic Absorption Spectroscopy (AAS) elemental standards as either nitrate or chloride solutions to prevent oxidation of the metal powders. The dried sulfur mixture was mixed with Fe and Ni powders and mechanically mixed before two aliquots were placed in separate SiO2 tubes. Each tube was held under vacuum for ~30 minutes, sealed under vacuum, and then heated at 800C for 48 hours. Like [4], the synthesis products were composed of pourous sulfide crystals. Major element analyses of both experimental aliquots, collected using an Electron Probe Microanalyser (EPMA), yield indistinguishable major element compositions (uncertainties in 2SE & 2RSE[%]), with an average of 57.90  0.09 (0.16 %), 4.95  0.03 (0.55 %), and 39.70  0.14 (0.34 %), for Fe, Ni, and S, respectively. Trace element data were measured using a Photon Machines 193nm laser ablation system coupled to a Thermo-Scientific Element-XR ICP-MS. Spot sizes were limited to 50 μm due to the porous nature of the sulfide target material. Trace element abundances, normalized to Fe as an internal standard, were also found to be homogenous between the two aliquots, with weighted mean 2RSE (%) values of <3.0 for all trace elements. Synthesized products were re-powdered and absolute concentrations measured via solution ICP-MS. Although the sulfide appears to be homogenous, sintering experiments will be performed to more closely match the standard density to natural sulfides and minimize differences in ablation behavior. Improved density also allows for higher sensitivity (i.e. more compact target material) and larger spot sizes or traverses, as void space is eliminated. Additional major and trace element analyses on the products of the sintering experiments will be undertaken.

Jacob B Setera↗
NASA NTRS2000

Independent Component Analysis of Textures

A common method for texture representation is to use the marginal probability densities over the outputs of a set of multi-orientation, multi-scale filters as a description of the texture. We propose a technique, based on Independent Components Analysis, for choosing the set of filters that yield the most informative marginals, meaning that the product over the marginals most closely approximates the joint probability density function of the filter outputs. The algorithm is implemented using a steerable filter space. Experiments involving both texture classification and synthesis show that compared to Principal Components Analysis, ICA provides superior performance for modeling of natural and synthetic textures.

Manduchi, Roberto↗
NASA NTRS2002

The Indirect Effect of UV: Some Good News for Microbes?

Ultraviolet (UV) radiation is of great concern because its biological effects are predominantly harmful. UV damage may be direct or indirect, the latter mediated through the photochemical production of reactive oxygen species such as hydrogen peroxide. We measured the effect of H2O2 on various microbes both in the lab and in nature. At our study site in Yellowstone National Park, there is a UV-induced diurnal fluctuation of H2O2 extending up to one micron. Levels of DNA synthesis resulting from exposure to H2O2 were measured in several algal mats. Within naturally-occurring concentrations of H2O2, DNA synthesis increased. Laboratory studies showed that similar concentrations of H2O2 induce mitosis. We hypothesize that the low levels of H2O2 encountered in nature are inducing mitotic division. At higher levels of H2O2 a second peak in DNA synthesis was found which we interpret to represent DNA damage repair. These experiments suggest that in nature, the low levels of H2O2 produced may have a mitogenic rather than damaging effect. Assuming early levels of UV radiation were substantially higher at the time protists evolved, differential mitogenic effects could have influenced protistan evolution. With H2O2 likely to be present on such bodies as Mars and Europa, the response of organisms will be concentration-dependent and not linear.

Rothschild, Lynn J.↗
NASA NTRS2003

Electric Field Effects in Self-Propagating High-Temperature Synthesis under Microgravity Conditions

Self-propagating high-temperature synthesis (SHS) has been used to form many materials. SHS generally involves mixing reactants together (e.g., metal powders) and igniting the mixture such that a combustion (deflagration) wave passes though the mixture. The imposition of an electric field (AC or DC) across SHS reactants has been shown to have a marked effect on the dynamics of wave propagation and on the nature, composition, and homogeneity of the product . The use of an electric field with SHS has been termed "field-assisted SHS". Combustion wave velocities and temperatures are directly affected by the field, which is typically perpendicular to the average wave velocity. The degree of activation by the field (e.g., combustion rate) is related to the current density distribution within the sample, and is therefore related to the temperature-dependent spatial distribution of the effective electrical conductivity of reactants and products. Furthermore, the field can influence other important SHS-related phenomena including capillary flow, mass-transport in porous media, and Marangoni flows. These phenomena are influenced by gravity in conventional SHS processes (i.e., without electric fields). As a result the influence of the field on SHS under reduced gravity is expected to be different than under normal gravity. It is also known that heat loss rates from samples, which can depend significantly on gravity, can influence final products in SHS. This research program is focused on studying field-assisted SHS under reduced gravity conditions. The broad objective of this research program is to understand the role of an electric field in SHS reactions under conditions where gravity-related effects are suppressed. The research will allow increased understanding of fundamental aspects of field-assisted SHS processes as well as synthesis of materials that cannot be formed in normal gravity.

Unuvar, C.↗
NASA NTRS1999

Radiation: microbial evolution, ecology, and relevance to mars missions

Ultraviolet (UV) radiation has been an important environmental parameter during the evolution of life on Earth, both in its role as a mutagen and as a selective agent. This was probably especially true during the time from 3.8 to 2.5 billion years ago, when atmospheric ozone levels were less than 1% of present levels. Early Mars may not have had an "ozone shield" either, and it never developed a significant one. Even though Mars is farther away from the Sun than the Earth, a substantial surficial UV flux is present on Mars today. But organisms respond to dose rate, and on Mars, like on Earth, organisms would be exposed to diurnal variations in UV flux. Here we present data on the effect of diurnal patterns of UV flux on microbial ecosystems in nature, with an emphasis on photosynthesis and DNA synthesis effects. These results indicate that diurnal patterns of metabolism occur in nature with a dip in photosynthesis and DNA synthesis in the afternoon, in part regulated by UV flux. Thus, diurnal patterns must be studied in order to understand the effect of UV radiation in nature. The results of this work are significant to the success of human missions to Mars for several reasons. For example, human missions must include photosynthetic organisms for food production and likely oxygen production. An evolutionary approach suggests which organisms might be best suited for high UV fluxes. The diurnal aspect of these studies is critical. Terraforming is a potential goal of Mars exploration, and it will require studies of the effect of Martian UV fluxes, including their diurnal changes, on terrestrial organisms. Such studies may suggest that diurnal changes in UV only require mitigation at some times of day or year.

Review, Tutorial↗
NASA NTRS2001

Approaches for Exploring the Organic Evolution of Titan's Surface

Saturn's largest moon Titan has a cold, very dense nitrogen atmosphere rich in methane and the hydrocarbon and nitride products of methane photolysis. Sources of energy for atmospheric chemistry include solar ultraviolet radiation, Saturn magnetospheric particles, and galactic cosmic rays. The chemistry of Titan's atmosphere, while interesting from the point of view of planetary photochemistry, is largely free radical driven and therefore not particularly suited to the synthesis of polymeric biomolecules or even their precursors. However, the nature of Titan's atmosphere, in particular its redox state (hydrogen escapes rapidly and is under abundant compared to in the giant planets), and the presence of a variegated surface make consideration of surface chemistry on Titan interesting from an astrobiological viewpoint. Additional information is contained in the original extended abstract.

Beauchamp, P.↗