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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 343 records · Page 19
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

Concentration-Discharge Relationships in the Six Largest Arctic Rivers, 2003-2019

This dataset provides the results of the analysis of the relationship of dissolved analyte concentrations and river discharges in the six largest Arctic rivers across the global panarctic region (see Figure 1 in documentation file *.pdf). Long-term measurements of dissolved analyte concentrations and river discharge have been collected for each of the Kolyma, Lena, Mackenzie, Ob, Yenisey, and Yukon rivers by the Arctic Great Rivers Observatory (ArcticGRO) project from ~2003-present (Shiklomanov, 2021). The relationship of dissolved analyte concentrations and discharges in each river was characterized by statistical analysis of the slope of the log(concentration) vs log(discharge) (b), the coefficient of variation ratio (CVc/CVq), the 2.5% and 97.5% confidence intervals of b, and assigning a chemostatic, flushing, diluting, or non-systematic behavior category according to Koger (2018). The summary of these analyses for all six rivers is provided in one .csv file. The concentrations of 20 dissolved analytes and discharge measurement data for the individual Kolyma, Lena, Mackenzie, Ob, Yenisey, and Yukon rivers are also provided with this dataset. There are seven *.csv files; one for each river plus the statistical summary. These public ArcticGRO data at "https://www.arcticgreatrivers.org" (Shiklomanov, 2021) were downloaded on Feb 13, 2020, but each river has different measurement dates over the sampling and analysis period. The ArcticGRO metadata document (*.pdf) downloaded on Feb 13, 2020 is also included in this dataset. The Next-Generation Ecosystem Experiments: Arctic (NGEE Arctic), was a research effort to reduce uncertainty in Earth System Models by developing a predictive understanding of carbon-rich Arctic ecosystems and feedbacks to climate. NGEE Arctic was supported by the Department of Energy's Office of Biological and Environmental Research. The NGEE Arctic project had two field research sites: 1) located within the Arctic polygonal tundra coastal region on the Barrow Environmental Observatory (BEO) and the North Slope near Utqiagvik (Barrow), Alaska and 2) multiple areas on the discontinuous permafrost region of the Seward Peninsula north of Nome, Alaska. Through observations, experiments, and synthesis with existing datasets, NGEE Arctic provided an enhanced knowledge base for multi-scale modeling and contributed to improved process representation at global pan-Arctic scales within the Department of Energy's Earth system Model (the Energy Exascale Earth System Model, or E3SM), and specifically within the E3SM Land Model component (ELM).

54 ENVIRONMENTAL SCIENCES↗
NASA NTRS1978

Lonar crater glasses and high-magnesium australites - Trace element volatilization and meteoritic contamination

Radiochemical neutron activation analysis was used to detect six siderophile elements (Ni, Re, Os, Pd, Ir and Au) and three volatile elements (Zn, Se and Cd) in two basalts, a pumice and three impact glasses from Lonar crater, India, and in six high-magnesium australites. Significant depletions in Re and Se with respect to the parent basalts were found in the Lonar glasses. These depletions, apparently correlated with the degree of shock, are probably due to volatilization under the oxidizing conditions characteristic of earth. One of the australites is substantially enriched in siderophiles relative to the level of these elements in the other five tektites. The element patterns in the australites resemble those of the carbonaceous or cometary component of an Apollo 16 soil.

Morgan, J. W.↗
NASA NTRS1980

Status of the DOE/NASA critical gas turbine research and technology project

Activities performed in order to provide an R&T data base for utility gas turbine systems burning coal-derived fuels are described. Experiments were run to determine the corrosivity effects of trace metal contaminants (and potential fuel additives) on gas turbine materials and these results were correlated in a corrosion-life prediction model. Actual fuels were burned in a burner rig hot corrosion test to verify the model. A deposition prediction model was assembled and compared with results of actual coal-derived fuel deposition tests. Thermal barrier coatings were tested to determine their potential for protecting gas turbine hardware from the corrosive contaminants. Several coatings were identified with significantly improved spallation-resistance (and, hence, corrosion resistance).

Clark, J. S.↗
NASA NTRS1980

A fundamental approach to adhesion: Synthesis, surface analysis, thermodynamics and mechanics

Several techniques were used to study pretreated Ti 6-4 surfaces including scanning electron microscopy (SEM), electron spectroscopy of chemical analysis (ESCA), and, reflectance visible spectroscopy. Each pretreatment type gave a characteristic surface morphology as seen by SEM. Elemental analysis of the Ti 6-4 surfaces was done using ESCA. Trace residual contaminants from particular chemical pretreatments were identified readily. Results indicate that reflectance visible spectroscopy using indicator dyes placed on Ti 6-4 surfaces appears to be a feasible approach to establish surface acidity. Differences in surface acidity were observed using bromthymol blue on Ti 6-4 surfaces pretreated by two different methods.

Beck, B.↗
NASA NTRS1980

Status of the DOE/NASA critical gas turbine R & T Project

The purpose of the DOE/NASA CRT (Critical Research and Technology) Project at the Lewis Research Center is to provide an R&T data base for utility gas turbine systems burning coal-derived fuels. Coal-derived fuels present difficult problems in combustion (because of the high organically-bound nitrogen in the fuel), and materials (because of the trace metal contaminant levels in the fuels, leading to corrosion and deposition in the turbine hot section). The combustion task includes (1) an effort to model the rich-lean combustion process, to predict NOx emissions; (2) a two-stage flame tube experiment to study the effects of combustion operating conditions and fuel properties on NOx conversion; and (3) scaled combustor tests to evaluate the NOx-reduction potential of several staged-combustion concepts. The materials-corrosion resistance effort attacks the problem on three sides.

Clark, J. S.↗
NASA NTRS1980

Spectroscopic characterization of titanium 6-4 surfaces after chemical pretreatments

Several techniques have been used to study pretreated Ti 6-4 surfaces including scanning electron microscopy (SEM), electron spectroscopy of chemical analysis (ESCA), and, reflectance visibile spectroscopy. Each pretreatment type gives a characteristic surface morphology as seen by SEM. Elemental analysis of the Ti 6-4 surfaces was done using ESCA. Trace residual contaminants from particular chemical pretreatments are identified readily. Reflectance visible spectroscopy using indicator dyes placed on Ti 6-4 surfaces appears to be a feasible approach to establish surface acidity. Differences in surface acidity have been observed using bromthymol blue on Ti 6-4 surfaces pretreated by two different methods.

Chen, W.↗
NASA NTRS1986

Nebulization reflux concentrator

A nebulization reflux concentrator for removing trace gas contaminants from a sample gas is described. Sample gas from a gas supply is drawn by a suction source into a vessel. The gas enters the vessel through an atomizing nozzle, thereby atomizing and entraining a scrubbing liquid solvent drawn through a siphon tube from a scrubbing liquid reservoir. The gas and entrained liquid rise through a concentrator and impinge upon a solvent phobic filter, whereby purified gas exits through the filter housing and contaminated liquid coalesces on the solvent phobic filter and falls into the reservoir.

Collins, V. G.↗
NASA NTRS1991

Catalytic oxidation for treatment of ECLSS and PMMS waste streams

It is shown that catalytic oxidation is an effective technique for the removal of trace organic contaminants in a multifiltration potable processor's effluent. Essential elements of this technology are devices that deliver oxygen to the influent, and remove gaseous reaction byproducts from the effluent, via hollow-tube, gas-permeable membranes. Iodine, which poisons existing catalysis, is removed by a small deiodination bed prior to catalytic reactor entrance. The catalyst used is a mixture of Pt and Ru deposited on carbon, operating at 125-160 C and 39-90 psi pressures.

Akse, James R.↗
NASA NTRS1992

Regenerative life support technology challenges for the Space Exploration Initiative

Regenerative life support systems have been identified as one of the critical enabling technologies for future human exploration of space. This discipline encompasses processes and subsystems which regenerate the air, water, solid waste, and food streams typical of human habitation so as to minimize the mass and volume of stored consumables which must accompany the humans on a mission. A number of key technology challenges within this broad discipline are described, ranging from the development of new physical, chemical, and biological processes for regenerating the air, water, solid waste, and food streams to the development of improved techniques for monitoring and controlling microbial and trace constituent contamination. A continuing challenge overarching the development of these new technologies is the need to minimize the mass, volume, and electrical power consumption of the flight hardware. More important for long duration exploration missions, however, is the development of highly reliable, long-lived, self- sufficient systems which absolutely minimize the logistics resupply and operational maintenance requirements of the life support system and which ensure human safety through their robust, reliable operating characteristics.

Bilardo, Vincent J., Jr.↗
NASA NTRS1997

Evaluation of HAN-TEAN Stabilizers using Microcalorimetry

HAN-TEAN (hydroxylammonium nitrate - triethanolammonium nitrate - in water) is being considered for various propellant applications. This propellant has advantages in terms of insensitivity to impact and fire, low vapor pressure and environmentally benign reaction products. One office concerns with HAN-TEAN is its stability and shelf-life, especially when contaminated with trace metals. Stabilizer systems, consisting of anti-oxidants and/or chealating agents were investigated for their ability to control the decomposition of HAN-TEAN. Isothermal microcalorimetry, an ultrasensitive heat measurement technique, was used to monitor the decomposition of HANTEAN at near ambient temperatures. Isothermal microcalorimetry measures the heat flow from a reaction vessel into a surrounding heat sink. Microcalorimetry is approximately 1,000 times more sensitive than accelerating rate calorimetry (ARC) or differential scanning calorimetry (DSC) for measuring heat flow. Samples of HAN-TEAN containing the stabilizers were spiked with 50 ppm iron and the heat evolution monitored for a period of at least 30 days. Ten stabilizer combinations were tested and the rates of HAN-TEAN decomposition were lowered by 74 to 95 percent in the presence of iron.

Hornung, Steven D.↗
NASA NTRS2003

Cabin Air Quality Dynamics On Board the International Space Station

Spacecraft cabin air quality is influenced by a variety of factors. Beyond normal equipment offgassing and crew metabolic loads, the vehicle s operational configuration contributes significantly to overall air quality. Leaks from system equipment and payload facilities, operational status of the atmospheric scrubbing systems, and the introduction of new equipment and modules to the vehicle all influence air quality. The dynamics associated with changes in the International Space Station's (ISS) configuration since the launch of the U.S. Segment s laboratory module, Destiny, is summarized. Key classes of trace chemical contaminants that are important to crew health and equipment performance are emphasized. The temporary effects associated with attaching each multi-purpose logistics module (MPLM) to the ISS and influence of in-flight air quality on the post-flight ground processing of the MPLM are explored.

Perry, J. L.↗