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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 55 records · Page 3
All sourcesNASA NTRSDOE OSTI
NASA NTRS1993

Tambo Quemado: Extraordinary concentrations of REE and refractory trace elements caused by artificial heating

Buchwald examined samples of the IIIB iron Tambo Quemado (TAMQ) cut from the 130 kg main mass. He determined it had been artificially heated, at some time prior to being reported, in an attempt to obtain metal from it. Although the Widmanstatten structure appears relatively unaffected under macroscopic examination, microscopic study of etched sections reveals the effect of the heating. Taenite and plessite area boundaries are indistinct due to high temperature diffusion. Schreibersite, once present in significant amounts, has been melted. Schreibersites in the interior have resolidified in fine-grained eutectic textures surrounded by dark-etching metal rims supersaturated with phosphorus. Buchwald states that phosphate minerals were probably present originally, because graftonite, and its polymorph sarcopside (both essentially Fe3(PO4)2), are common in irons of the IIIB groups. Based on his metallographic study Buchwald estimates TAMQ was heated to 1000 C for about one hour. An interior sample from TAMQ was examined in order to determine what effect this unintended heating 'experiment' had upon the phosphate phases.

Olsen, E.↗
NASA NTRS1993

Correlated petrographic, electron microprobe, and ion microprobe studies of selected primitive and processed phase assemblages in meteorites

During the past three years we have received support to continue our research in elucidating the formation and alteration histories of selected meteoritic materials by a combination of petrographic, trace element, and isotopic analyses employing optical and scanning electron microscopes and electron and ion microprobes. The awarded research funds enabled the P.I. to attend the annual LPSC, the co-I to devote approximately 15 percent of his time to the research proposed in the grant, and partial support for a visiting summer post-doctoral fellow to conduct electron microprobe analyses of meteoritic samples in our laboratory. The research funds, along with support from the NASA Education Initiative awarded to P.I. G. Wasserburg, enabled the co-I to continue a mentoring program with inner-city minority youth. The support enabled us to achieve significant results in the five projects that we proposed (in addition to the Education Initiative), namely: studies of the accretional and post-accretional alteration and thermal histories in CV meteorites, characterization of periclase-bearing Fremdlinge in CV meteorites, characterization of Ni-Pt-Ge-Te-rich Fremdlinge in CV meteorites in an attempt to determine the constraints they place on the petrogenetic and thermal histories of their host CAI's, correlated electron and ion microprobe studies of silicate and phosphate inclusions in the Colomera meteorite in an attempt to determine the petrogenesis of the IE iron meteorites, and development of improved instrumental and correction procedures for improved accuracy of analysis of meteoritic materials with the electron microprobe. This grant supported, in part or whole, 18 publications so far by our research team, with at least three more papers anticipated. The list of these publications is included. The details of the research results are briefly summarized.

Albee, Arden L.↗
NASA NTRS2004

A Quantitative NMR Analysis of Phosphorus in Carbonaceous and Ordinary Chondrites

Phosphorus is important in a number of biochemical molecules, from DNA to ATP. Early life may have depended on meteorites as a primary source of phosphorus as simple dissolution of crustal apatite may not produce the necessary concentration of phosphate. Phosphorus is found in several mineral phases in meteorites. Apatite and other Ca- and Mg phosphate minerals tend to be the dominant phosphorus reservoir in stony meteorites, whereas in more iron-rich or reduced meteorites, the phosphide minerals schreibersite, (Fe, Ni)3P, and perryite, (Ni, Fe)5(Si, P)2 are dominant. However, in CM chondrites that have experienced significant aqueous alteration, phosphorus has been detected in more exotic molecules. A series of phosphonic acids including methyl-, ethyl-, propyl- and butyl- phosphonic acids were observed by GC-MS in Murchison. Phosphorian sulfides are in Murchison and Murray. NMR spectrometry is capable of detecting multiple substances with one experiment, is non-destructive, and potentially quantitative, as discussed below. Despite these advantages, NMR spectrometry is infrequently applied to meteoritic studies due in large part to a lack of applicability to many compounds and the relatively high limit of detection requirements. Carbon-13 solid-state NMR has been applied to macromolecular carbon in Murchison. P-31 NMR has many advantages over aqueous carbon-13 NMR spectrometry. P-31 is the only isotope of phosphorus, and P-31 gives a signal approximately twice as strong as C-13. These two factors together with the relative abundances of carbon and phosphorus imply that phosphorus should give a signal approximately 20 as strong as carbon in a given sample. A discussion on the preparation of the quantitative standard and NMR studies are presented

Pasek, M. A.↗
NASA NTRS1985

Cyanobacterial mats: Microanalysis of community metabolism

The microbial communities in two sites were studied using several approaches: (1) light microscopy; (2) the measurement of microprofiles of oxygen and sulfide at the surface of the microbial mat; (3) the study of diurnal variation of oxygen and sulfides; (4) in situ measurement of photosynthesis and sulfate reduction and study of the coupling of these two processes; (5) measurement of glutathione in the upper layers of the microbial mat as a possible oxygen quencher; (6) measurement of reduced iron as a possible intermediate electron donor along the established redoxcline in the mats; (7) measurement of dissolved phosphate as an indicator of processes of break down of organic matter in these systems; and (8) measurement of carbon dioxide in the interstitial water and its delta C-13 in an attempt to understand the flow of CO2 through the systems. Microbial processes of primary production and initial degradation at the most active zone of the microbial mat were analyzed.

Cohen, Y.↗
NASA NTRS1992

Characterization of the Water Soluble Component of Inedible Residue from Candidate CELSS Crops

Recycling of inorganic nutrients required for plant growth will be a necessary component of a fully closed, bioregenerative life support system. This research characterized the recovery of plant nutrients from the inedible fraction of three crop types (wheat, potato, and soybean) by soaking, or leaching, in water. A considerable portion of the dry weight of the inedible biomass was readily soluble (29 percent for soybean, 43 percent for wheat, and 52 percent for potato). Greater weight loss from potato was a result of higher tissue concentrations of potassium, nitrate, and phosphate. Approximately 25 percent of the organic content of the biomass was water soluble, while the majority of most inorganic nutrients, except for calcium and iron, were recovered in the leachate. Direct use of the leachates in hydroponic media could provide between 40-90 percent of plant nutrient demands for wheat, and 20-50 percent of demand for soybean and potato. Further evaluation of leaching as a component of resource recovery scheme in a bioregenerative system requires study of (1) utilization of plant leachates in hydroponic plant culture; and (2) conversion of organic material (both soluble and insoluble) into edible, or other useful, products.

Garland, Jay↗
NASA NTRS1976

An experimental study of phosphate reduction and phosphorus-bearing lunar metal particles

Results are reported for two sets of experiments conducted to investigate the distribution and origin of phosphorus in lunar metal particles. The first set measured the equilibrium oxygen fugacity as a function of temperature for synthesized Fe-Ni and Fe-Ni-P alloys; the second set imposed various oxygen pressures so that the P distribution among the coexisting phases could be observed. The conditions of temperature, oxygen fugacity, and time necessary to produce P contents similar to those found in lunar metal particles are determined. The results show that: (1) the P distribution in lunar-type metal is controlled by oxygen fugacity, temperature, and bulk composition; (2) the P distribution is limited by the reaction rate at the metal surface and by the amount of phosphate in contact with the metal; (3) the nucleation and growth rate of phosphate controls the rate of P loss during oxidation; and (4) an oxygen fugacity of 10 to the -20th power atm at 950 C is required to saturate iron with P. It is concluded that a reducing species such as carbon may establish a local equilibrium and prevent oxygen communication with the surrounding rock.

Friel, J. J.↗
NASA NTRS2018

Physical and Biological Properties of Cobalt- and Copper-Doped Calcium Phosphates as Bone Substitute Materials

Arthritis, osteoporosis, and other bone diseases and defects are common medical issues worldwide. By utilizing ceramic biomaterials as bone substitutes to treat these diseases, bone regeneration can be promoted and toxicity from the substitute material can be limited. Calcium phosphate (CaP) ceramics have become popular as bone substitutes due to their biocompatibility and similarity in composition to natural bone. The purpose of this research was to investigate the physical properties and biological responses of CaP-based bone substitutes, doped with metal ions. Some metal ions are present in natural bone in small amounts, and recent studies show they affect the biological responses of CaPs significantly. Dopants such as magnesium (Mg), strontium (Sr), silicon (Si) and iron (Fe) alter the phase composition, mechanical properties, osteogenesis and angiogenesis properties of CaPs, depending on their concentration and method of addition. In the present study, the effects of cobalt (Co) and copper (Cu) on the physical and biological properties of two main CaP materials, brushite cement (BrC) and tricalcium phosphate (TCP), have been investigated. Different concentrations of dopants in forms of oxide and/or chloride were selected and their effect on phase composition, sintering behavior, density, setting time, compressive strength and in vitro interaction with osteosarcoma and osteoblast cells were studied. Different techniques of sample preparation, challenges during cement preparation and compact sample pressing, sintering, and methods of dopant addition are discussed. The presence of Cu in tricalcium phosphate was found to increase thermal stability of the material and decrease the impact of sintering temperature on porosity. In addition, Cu caused a reduction in expression of inflammatory gene markers by human osteoblast cells and an increased expression at early time points due of osteoinductive markers.The addition of Cu and Co to brushite cement caused an increase in thermal stability of the material, and the addition of Cu caused significant increase in setting time. Small dopant amounts of Co caused decrease in setting time, but higher amounts caused an increase. In addition, Cu dopant in small amounts resulted in an increase of compressive strength. Both Cu and Co led to a decrease in expression of inflammatory gene markers by osteoblast and osteosarcoma cells respectively, and Cu also caused an increase in osteoinductive marker expression. Thus, these results indicate that Cu and Co have a positive impact on the physical, mechanical and biological properties of calcium phosphate biomaterials.

Cummings, Haley V.↗
NASA NTRS2004

Lunar and Planetary Science XXXV: Weird Martian Minerals: Complex Mars Surface Processes

The session "Complex Mars Surface" included the following reports:A Reappraisal of Adsorbed Superoxide Ion as the Cause Behind the Reactivity of the Martian Soils; Sub-Surface Deposits of Hydrous Silicates or Hydrated Magnesium Sulfates as Hydrogen Reservoirs near the Martian Equator: Plausible or Not?; Thermal and Evolved Gas Analysis of Smectites: The Search for Water on Mars; Aqueous Alteration Pathways for K, Th, and U on Mars; Temperature Dependence of the Moessbauer Fraction in Mars-Analog Minerals; Acid-Sulfate Vapor Reactions with Basaltic Tephra: An Analog for Martian Surface Processes; Iron Oxide Weathering in Sulfuric Acid: Implications for Mars; P/Fe as an Aquamarker for Mars; Stable Isotope Composition of Carbonates Formed in Low-Temperature Terrestrial Environments as Martian Analogs; Can the Phosphate Sorption and Occlusion Properties Help to Elucidate the Genesis of Specular Hematite on the Mars Surface?; Sulfate Salts, Regolith Interactions, and Water Storage in Equatorial Martian Regolith; Potential Pathways to Maghemite in Mars Soils: The Key Role of Phosphate; and Mineralogy, Abundance, and Hydration State of Sulfates and Chlorides at the Mars Pathfinder Landing Site.

Source record↗
NASA NTRS1984

Phosphoran pyroxene and olivine in silicate inclusions in natural iron-carbon alloy, Disko Island, Greenland

A survey of literature data on the P contents of olivine, pyroxene, and garnet in mantle xenoliths and the bulk P contents of mantle xenoliths shows that available data is ambiguous as to whether mantle P is primarily contained in silicates or in phosphates, even though phosphates are rarely observed in mantle xenoliths. Garnet probably contains more of the mantle's P than olivine or pyroxene. Bulk P contents of mantle xenoliths vary significantly. Estimation of the primitive mantle P content from xenoliths requires interpretation of the partial melting and contamination histories of the xenoliths.

Goodrich, C. A.↗
NASA NTRS1993

The dregs of crystallization in Zagami

The Zagami shergottite is a basaltic meteorite which formed when a phenocryst-bearing lava flow was emplaced at or near the surface of Mars. Recently, a cm-sized olivine-rich lithology has been identified in Zagami by Mossbauer spectroscopy. Olivine is extremely rare in shergottites, particularly in Zagami and Shergotty, where it occurs only as minute grains. We report petrologic and microprobe studies of this olivine-rich lithology. This material represents the last few percent of melt and is highly enriched in phosphates, opaques and mesostases, all of which are late-stage crystallization products. Phosphates replaced augite as a phenocryst phase when the magma became saturated in P. This late stage melt also includes a fayalite-bearing, multi-phase intergrowth which crystallized after the melt became too rich in iron to crystallize pigeonite. We can now reconstruct the entire crystallization history of the Zagami shergottite from a deep-seated magma chamber to crystallization of the final few percent of melt in a near-surface dike or thick flow. Small pockets (tens of microns) of late-stage melt pockets are ubiquitous but volumetrically minor in Zagami. We do not know the physical relationship between these areas and the cm-sized olivine-rich material described here. It is possible that these small pockets were mobile, forming larger areas. Perhaps inspection of the entire hand specimen of Zagami would clarify this relationship.

Mccoy, T. J.↗
NASA NTRS1994

Phosphate microaggregates in Archean sediments

Light microscopy conducted on samples of Archean sediments reveals phosphate microaggregates which are suggestive of a biotic origin (Arrhenius et al., 1993). These aggregates, typically 15 micrometers wide and 50 micrometers long, are thought to be the mineral remains of colonies of microorganisms that lived during the late Archean Eon (greater than or equal to 2.5 Ga). Confocal microscopy was used to study the structures of these microaggregates in three dimensions. Samples used in this study are from the lowermost section of drill core taken from the Dales Gorge Member of the Brockman Iron-Formation (Hamersley Basin) in Western Australia. These sediments are well-preserved and escaped extensive metamorphism typically experienced by older rocks of this type. Two types of samples were prepared for study under the microscope: thin sections (30 micrometers) for transmitted light microscopy to study the general rock texture and to locate the grains of interest, and thick sections (3mm) for confocal microscopy to determine the 3-D structure of the aggregates in situ. The samples have been carefully polished so that they may be directly placed on the oil-immersion lens without the use of a cover slip. No chemical treatments of the surfaces have been performed. The aggregates often form clusters, although isolated aggregates have also been found. The clusters tend to distribute along microbands in the rocks. Electron microprobe analyses show that the phosphate grains and their inclusions, besides calcium and phosphorus, contain no major elements heavier than sodium. The proportions of calcium to phosphorus, the absence of stoichiometric amounts of other cations such as magnesium and iron, as well as optical properties suggest apatite as the mineral form.

Mojzsis, S.↗
NASA NTRS2001

Gene amplification and microsatellite instability induced in tumorigenic human bronchial epithelial cells by alpha particles and heavy ions

Gene amplification and microsatellite alteration are useful markers of genomic instability in tumor and transformed cell lines. It has been suggested that genomic instability contributes to the progression of tumorigenesis by accumulating genetic changes. In this study, amplification of the carbamyl-P-synthetase, aspartate transcarbamylase, dihydro-orotase (CAD) gene in transformed and tumorigenic human bronchial epithelial (BEP2D) cells induced by either alpha particles or (56)Fe ions was assessed by measuring resistance to N-(phosphonacetyl)-l-aspartate (PALA). In addition, alterations of microsatellite loci located on chromosomes 3p and 18q were analyzed in a series of primary and secondary tumor cell lines generated in nude mice. The frequency of PALA-resistant colonies was 1-3 x 10(-3) in tumor cell lines, 5-8 x 10(-5) in transformed cells prior to inoculation into nude mice, and less than 10(-7) in control BEP2D cells. Microsatellite alterations were detected in all 11 tumor cell lines examined at the following loci: D18S34, D18S363, D18S877, D3S1038 and D3S1607. No significant difference in either PALA resistance or microsatellite instability was found in tumor cell lines that were induced by alpha particles compared to those induced by (56)Fe ions.

Non-NASA Center↗
NASA NTRS2006

Phosphate Reactions as Mechanisms of High-Temperature Lubrication

One of the major problems preventing the operation of advanced gas turbine engines at higher temperatures is the inability of currently used liquid lubricants to survive at these higher temperatures under friction and wear conditions. Current state-of-the-art organic liquid lubricants rapidly degrade at temperatures above 300 C; hence some other form of lubrication is necessary. Vapor-phase lubrication is a promising new technology for high-temperature lubrication. This lubrication method employs a liquid phosphate ester that is vaporized and delivered to bearings or gears; the vapor reacts with the metal surfaces, generating a solid lubricious film that has proven very stable at high temperatures. In this study, solid lubricious films were grown on cast-iron foils in order to obtain reaction and diffusion rate data to help characterize the growth mechanism. A phenomenological mathematical model of the film deposition process was derived incorporating transport and kinetic parameters that were coupled to the experimental data. This phenomenological model can now be reliably used as a predictive and scale-up tool for future vapor-phase lubrication studies.

Nagarajan, Anitha↗
NASA NTRS2015

Recognizing Sulfate and Phosphate Complexes Adsorbed onto Nanophase Weathering Products on Mars

Nanophase weathering products (i.e., secondary phases that lack long-range atomic order) have been recognized on the martian surface via orbital observations and in-situ measurements from landed missions. Allophane, a poorly crystalline, hydrated aluminosilicate, has been identified at the regional scale in models of thermal-infrared (TIR) data from the Thermal Emission Spectrometer (TES) and at the local scale from visible/near-IR (VNIR) data from the Compact Reconnaissance Impact Spectrometer for Mars (CRISM) instrument and phase calculations of Alpha Particle X-ray Spectrometer (APXS) data of rocks encountered by the Mars Exploration Rovers (MER) Spirit and Opportunity. Nanophase iron oxides (npOx) have been recognized in rocks and soils measured by the Mössbauer Spectrometer on Spirit and Opportunity. Furthermore, analyses of X-ray diffraction data measured by the CheMin instrument onboard the Mars Science Laboratory rover Curiosity indicate rock and soil samples are comprised of approx. 20-50 wt.% X-ray amorphous materials. Chemical measurements by landed missions indicate the presence of sulfur and phosphorus in martian rocks in soils, and APXS data from Gusev crater demonstrate abundances of up to approx. 5 wt.% P2O5 and approx. 30 wt.% SO3. However, the speciation of phosphorus and sulfur is not always evident. On Earth, phosphate and sulfate anions can be chemisorbed onto the surfaces of nanophase weathering products. This process may also occur on Mars, and calculations of the composition of the amorphous component at Gale crater using CheMin mineral models and APXS data show that amorphous material is enriched in volatiles, including S. Here, we examine the ability to detect chemisorbed sulfate and phosphate complexes by analyzing sulfate- and phosphate-adsorbed nanophase weathering products using instruments similar to those on landed and orbital missions.

Rampe, E. B.↗
NASA NTRS1987

Phase equilibria in the iron oxide-cobalt oxide-phosphorus oxide system

Two novel ternary compounds are noted in the present study of 1000 C solid-state equilibria in the Fe-Co-P-O system's Fe2O3-FePO4-Co3(Po4)2-CoO region: CoFe(PO4)O, which undergoes incongruent melting at 1130 C, and Co3Fe4(PO4)6, whose incongruent melting occurs at 1080 C. The liquidus behavior-related consequences of rapidly solidified cobalt ferrite formation from cobalt ferrite-phosphate melts are discussed with a view to spinel formation. It is suggested that quenching from within the spinel-plus-liquid region may furnish an alternative to quenching a homogeneous melt.

De Guire, Mark R.↗
NASA NTRS1992

Effect of surface condition on the formation of solid lubricating films at high temperatures

Solid films were produced on active metal or ceramic surfaces using lubricants (such as tricresyl phosphate) delivered as a vapor at high temperatures, and the lubricity of these deposits under different dynamic wear conditions was investigated. A method is described for chemically activating ceramic surfaces resulting in a surface that could promote the formation of lubricating polymeric derivative of TCP. Experiments were carried out to evaluate the wear characteristics of unlubricated cast iron and of Sialon ceramic at 25 and 280 C, and lubricated with a vapor of TCP at 280 C. It is shown that continuous vapor phase lubrication of chemically treated Sialon reduced its coefficient of friction from 0.7 to less than 0.1.

Hanyaloglu, Bengi↗
NASA NTRS1983

Economy of precipitating agent application in municipal wastewater treatment facilities

Purification by precipitation in this study is not considered primarily as a means of phosphate removal but as a method for reduction of suspended solids BOD and COD. A dynamic calculation procedure is used to allow for exact determination of time dependent variation of costs. The results show that costs of wastewater treatment by precipitation may equal those of conventional primary clarification and secondary biological treatment, especially with low-cost iron-II-salts in simultaneous precipitation and in larger plants ( 20,000 PF). Cost advantages may be accrued in smaller plants by using the more expensive trivalent salts in pre-precipitation as compared to conventional low-load biological treatment. This is due mainly to better effluent quality and, consequently, lower wastewater fees (Wastewater Discharge Act). If the precipitant is dosed temporarily only during periods of highest pollution the savings can be about 5 to 10%.

Neis, U.↗
NASA NTRS2006

Acid Sulfate Weathering on Mars: Results from the Mars Exploration Rover Mission

Sulfur has played a major role in the formation and alteration of outcrops, rocks, and soils at the Mars Exploration Rover landing sites on Meridiani Planum and in Gusev crater. Jarosite, hematite, and evaporite sulfates (e.g., Mg and Ca sulfates) occur along with siliciclastic sediments in outcrops at Meridiani Planum. The occurrence of jarosite is a strong indicator for an acid sulfate weathering environment at Meridiani Planum. Some outcrops and rocks in the Columbia Hills in Gusev crater appear to be extensively altered as suggested by their relative softness as compared to crater floor basalts, high Fe(3+)/FeT, iron mineralogy dominated by nanophase Fe(3+) oxides, hematite and/or goethite, corundum-normative mineralogies, and the presence of Mg- and Casulfates. One scenario for aqueous alteration of these rocks and outcrops is that vapors and/or fluids rich in SO2 (volcanic source) and water interacted with rocks that were basaltic in bulk composition. Ferric-, Mg-, and Ca-sulfates, phosphates, and amorphous Si occur in several high albedo soils disturbed by the rover's wheels in the Columbia Hills. The mineralogy of these materials suggests the movement of liquid water within the host material and the subsequent evaporation of solutions rich in Fe, Mg, Ca, S, P, and Si. The presence of ferric sulfates suggests that these phases precipitated from highly oxidized, low-pH solutions. Several hypotheses that invoke acid sulfate weathering environments have been suggested for the aqueous formation of sulfate-bearing phases on the surface of Mars including (1) the oxidative weathering of ultramafic igneous rocks containing sulfides; (2) sulfuric acid weathering of basaltic materials by solutions enriched by volcanic gases (e.g., SO2); and (3) acid fog (i.e., vapors rich in H2SO4) weathering of basaltic or basaltic-derived materials.

Ming, Douglas W.↗