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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 325 records · Page 18
All sourcesNASA NTRSDOE OSTI
NASA NTRS1995

Study of Resource Recovery and Epidemiology in an Anaerobic Digester

Three 4-liter packed bed anaerobic digesters were fabricated and operated at 35 degrees C, pH around 7, and hydraulic retention time (HRT) of 20, 10 and 5 days to study the resource recovery and epidemiology in a controlled ecological life support system (CELSS). A simulated wastewater, consisted of shower water, clothwash water, dishwasher water, handwash water, and urine flush water was used as the feeding solution. Under steady-state operation, chemical oxygen demand (COD), total organic carbon (TOC), pH, nitrogen, phosphorus, and potassium wer monitored in the digester input and output solutions. The volume and the CH4/CO2 ratios in the biogas produced from the anaerobic digesters were measured. The results indicate about 90 percent of TOC is converted while only 5-8 percent of N-P-K are consumed in the digester. A multi-drug resistant strain of Salmonella choleraesuis was used as the indicator bacterium in the epidemiology study. The levels of Salmonella choleraesuis in the influent and the effluent wer determined and decimal decay rate constants, k(d), were estimated. The k(d) values were greater at higher initial doses than lower doses for the same HR, and greater for batch digestion (7.89/d) than for continuous digestion (4.28, 3.82, and 3.82/d for 20, 10, and 5 d HRT, respectively).

Li, K. Y.↗
NASA NTRS1980

Analysis of the origin of Aufeis feed-water on the arctic slope of Alaska

The origin of water feeding large aufeis fields (overflow river ice) on the Arctic Slope of Alaska is analyzed. Field measurements of two large aufeis fields on the eastern Arctic Slope were taken during July of 1978 and 1979. Measurements of aufeis extent and distribution were made using LANDSAT Multispectral Scanner Subsystem (MSS) satellite data from 1973 through 1979. In addition, ice cores were analyzed in the laboratory. Results of the field and laboratory studies indicate that the water derived from aufeis melt water has a chemical composition different from the adjacent upstream river water. Large aufeis fields are found in association with springs and faults thus indicating a subterranean origin of the feed water. In addition, the maximum extent of large aufeis fields was not found to follow meteorological patterns which would only be expected if the origin of the feed water were local. It is concluded that extent of large aufeis in a given river channel on the Arctic Slope is controlled by discharge from reservoirs of groundwater. It seems probable that precipitation passes into limestone aquifers in the Brooks Range, through an interconnecting system of subterranean fractures in calcareous rocks and ultimately discharges into alluvial sediments on the coastal plain to form aufeis. It is speculated that only small aufeis patches are affected by local meteorological parameters in the months just prior to aufeis formation.

Hall, D. K.↗
NASA NTRS2017

Estrous Cyclicity in Mice During Simulated Weightlessness

Hindlimb unloading (HU) is a rodent model system used to simulate weightlessness experienced in space. However, some effects of this approach on rodent physiology are under-studied, specifically the effects on ovarian estrogen production which drives the estrous cycle. To resolve this deficiency, we conducted a ground-based validation study using the HU model, while monitoring estrous cycles in 16-weeks-old female C57BL6 mice. Animals were exposed to HU for 12 days following a 3 day HU cage acclimation period, and estrous cycling was analyzed in HU animals (n=22), normally loaded HU Cage Pair-Fed controls (CPF; n=22), and Vivarium controls fed ad libitum (VIV; n=10). Pair feeding was used to control for potential nutritional deficits on ovarian function. Vaginal cells were sampled daily in all mice via saline lavage. Cells were dried and stained with crystal violet, and the smears evaluated using established vaginal cytology techniques by two individuals blinded to the animal treatment group. Estrous cyclicity was disrupted in nearly all HU and CPF mice, while those maintained in VIV had an average normal cycle length of 4.8+/- 0.5 days, with all stages in the cycle visibly observed. CPF and HU animals arrested in the diestrous phase, which precedes the pre-ovulatory estrogen surge. Additionally, infection-like symptoms characterized by vaginal discharge and swelling arose in several HU animals, which we suspect was due to an inability of these mice to properly groom themselves, and/or due to the change in the gravity vector relative to the vaginal opening, which prevented drainage of the lavage solution. Pair-feeding resulted in similar weight gains of HU and CPF (1.5% vs 3.0%, respectively). The current results indicate that pair-feeding controlled weight gain and that the HU cage alone influenced estrous cyclicity. Thus, longer acclimation needs to be tested to determine if and when normal estrous cycling resumes in non-loaded mice in HU cages prior to HU testing. Future studies might also examine whether modifications to the vaginal lavage procedure might prevent the onset of the infection-like symptoms, and allow estrous cyclicity to be measured in this model system. Research supported by NNX15AB48G to JST.

Hindlimb Unloading↗
NASA NTRS2016

FOST 2 Upgrade with Hollow-Fiber CTA FO Module and Generation of Osmotic Agent for Microorganism Growth Studies

FOST 2 is an integrated membrane system that incorporates a forward osmosis subsystem and a reverse osmosis subsystem working in series. It has been designed as a post treatment system to process the effluent from the Membrane Aerated Biological Reactor developed at NASA Johnson Space Center and Texas Tech University. Its function is to remove dissolved solids residual such as ammonia and suspended solids, as well as to provide a physical barrier to microbial and viral contamination. A tubular CTA membrane module from HTI and a flat-sheet lipid-base membrane module from Porifera were integrated and tested on FOST 2 in the past, using both a bioreactor's effluent and greywater as the feed solution. This paper documents the performance of FOST 2 after its upgrade with a hollow-fiber CTA membrane module from Toyobo, treating real black-water to generate the osmotic agent solution necessary to conduct growth studies of genetically engineered microorganism for the Synthetic Biological Membrane project.

Water treatment↗
NASA NTRS1975

One-third scale model of an offset fed scanning antenna for the shuttle imaging microwave system

An experimental study is reported, involving the design, fabrication, and measurement of a one-third scale model of the 4m diameter parabolic torus reflector with a Gregorian feed for the SIMS application. Antenna pattern measurements of the model at 60 and 30 GHz are presented to verify the predictions of a geometrical optics analysis upon which the antenna design was based. It is shown that the antenna measurements bear out the geometrical optics analysis in every respect and that the Gregorian subreflector feed is usable at all frequencies above at least 10 Ghz in the full size SIMS antenna. The fabrication of the model antenna is discussed, including a computerized technique for fabricating the transcendental subreflector shape with a numerically controlled machine.

Gustincic, J. H.↗
NASA NTRS1986

Mass Spectrometer for Airborne Micro-Organisms

Bacteria and other micro-organisms identified continously with aid of new technique for producing samples for mass spectrometer. Technique generates aerosol of organisms and feeds to spectrometer. Given species of organism produces characteristic set of peaks in mass spectrum and thereby identified. Technique useful for monitoring bacterial makeup in environmental studies and in places where cleanliness is essential, such as hospital operating rooms, breweries, and pharmaceutical plants.

Sinha, M. P.↗
NASA NTRS1985

Food Service Management

A study to design a food service system using current technology to serve a small scale Space Station was conducted. The psychological, sociological and nutritional factors affecting feeding in microgravity conditions was investigated. The logistics of the food service system was defined.

Rappole, C. L.↗
NASA NTRS1990

A comparison of KPNO CCD and coadded DAO photographic spectroscopic data

Spectra of field horizontal-branch A stars obtained with the coude feed telescope of the KPNO are compared with coadded spectrograms derived from the 2.4-m coude camera of the Dominion Astrophysical Observatory (DAO) in order to study variations in equivalent width for the same star. The KPNO and DAO data are also compared with the observations of Adelman and Hill (1987). It is observed that the SNRs are between 100-240 for the CCD images, 140 for the 6.8 A/mm coadditions, and 180 for the 2.4 A/mm coadditions, and that there is a 14 percent systematic difference in the equivalent widths. Factors which may affect the equivalent-width scale are discussed.

Adelman, Saul J.↗
NASA NTRS1992

Propellant production and useful materials: Hardware data from components and the systems

Research activities at the University of Arizona/NASA Space Engineering Research Center are described; the primary emphasis is on hardware development and operation. The research activities are all aimed toward introducing significant cost reductions through the utilization of resources locally available at extraterrestrial sites. The four logical aspects include lunar, Martian, support, and common technologies. These are described in turn. The hardware realizations are based upon sound scientific principles which are used to screen a host of interesting and novel concepts. Small scale feasibility studies are used as the screen to allow only the most promising concepts to proceed. Specific examples include: kg/day-class oxygen plant that uses CO2 as the feed stock, spent stream utilization to produce methane and 'higher' compounds (using hydrogen from a water electrolysis plant), separation of CO from the CO2, reduction of any iron bearing silicate (lunar soils), production of structural components, smart sensors and autonomous controls, and quantitative computer simulation of extraterrestrial plants. The most important feature of all this research continues to be the training of high-quality students for our future in space.

Ramohalli, Kumar↗
NASA NTRS1990

Technique for assessing vegetation-induced moisture flux, with implications for global climate modeling

The time between storms, the duration of storms, and the storm depths are studied in relation to vegetation controls on the disposition of rainfall. It is proposed that understanding the movement of water between the vegetation and soil (including evapotranspiration and infiltration) will be the gateway for modeling atmospheric flux and improving global climate models. The overall objective goal of the proposed research effort is to develop a field/lab methodology which will provide a better understanding of vegetation induced water movement. Water flow initiated from stem flow of wooded slopes feeds soil water pathways, which in turn feed the deeper ground water system and give rise to stream response. This is balanced by more water inputs via throughfall, where it percolates the soil matrix and allows much greater rates of evapotranspiration and atmospheric/soil moisture flux. This research study seeks to gain an understanding of the effect of vegetation on soil moisture, and the effect of this differential wetting on resulting evapotranspiration and atmospheric flux.

Macari, Emir Jose↗
NASA NTRS2022

Plasma Activated Water for Crewed Transit and Planetary Habitation: A Study of Gas Type, Electrode Material, and Power Supply Selection and the Impact on the Final Frontier - FY21 CIF

An in-depth study of plasma activated water (PAW) generation was conducted to link changes in power supply, electrode material, input gas, and treatment time to the resulting reaction chemistry. These changes in chemistry can help tailor PAW for different space applications. An AC, DC, and nanosecond (ns) pulsed power supply were each used to generate PAW with stainless steel, copper, tungsten, or platinum (Pt) electrodes while utilizing air, nitrogen (N2), carbon dioxide (CO2), helium (He), or argon (Ar) as the feed gas. Tap or deionized (DI) water was treated for 1 to 15 minutes, and the generated PAW was tested for changes in pH, conductivity, oxidation reduction potential, nitrates (NO3-), ammonium (NH4+), and peroxide. Calculations showed that the production of reactive nitrogen species was the leading cause of pH and conductivity changes. The DC generated air plasma was able to reduce the pH of DI water and generate NO3‑. The pulsed supply, operating at 20% of the input power of the DC supply, lowered the pH generated NO3‑. When a simulated Martian gas mixture of 95% CO2 and 5% N2 was used as the feed gas, NO3‑ was generated with the DC and pulsed supplies, respectively. Mixing PAW with plasma generated ash from inedible biomass allowed pH control, thus enhancing PAW’s potential use for sanitation applications. The large shift in pH was used to study sanitation effects of Escherichia coli (E. coli) reduction and Staphylococcus aureus (S. aureus), in which log reductions were found to be negligible. Additionally, the plasma generated ash in combination with PAW was also implemented in 10-day microgreen growth trials, in which PAW and ash resulted in quicker emergence of the microgreens compared to the standard growth conditions and comparable dry masses to Hoagland’s nutrient solution treated samples.

plasma activated water (PAW)↗
NASA NTRS1973

Development of a high speed parallel hybrid boost bearing

The analysis, design, and testing of the hybrid boost bearing are discussed. The hybrid boost bearing consists of a fluid film bearing coupled in parallel with a rolling element bearing. This coupling arrangement makes use of the inherent advantages of both the fluid film and rolling element bearing and at the same time minimizes their disadvantages and limitations. The analytical optimization studies that lead to the final fluid film bearing design are reported. The bearing consisted of a centrifugally-pressurized planar fluid film thrust bearing with oil feed through the shaft center. An analysis of the test ball bearing is also presented. The experimental determination of the hybrid bearing characteristics obtained on the basis of individual bearing component tests and a combined hybrid bearing assembly is discussed and compared to the analytically determined performance characteristics.

Winn, L. W.↗
NASA NTRS1984

Influence of stress, weightlessness, and simulated weightlessness on differentiation of preosteoblasts

The effects of 18.5 days of weightlessness aboard a satellite, stress of restricted feeding, stress of noise and vibration to simulate space flight and 21 days of head down suspension via the Morey-Holton model for simulated weightlessness was studied. Nuclear size of fibroblastlike cells in PDL on the anterior surface of maxillary first molars was classified as: (1) A-cells, self perpetuating precursors with a nuclear volume 80 micron B-cells, nonosteogenic fibroblasts with a nuclear volume of 80-119 micron 3, C-cells, preosteoblasts that are in G1 stage of the cell cycle with a nuclear size of 120-170 micro, and D-cells, preosteoblasts that are in G2 stage of the cell cycle with a nuclear size 170 micro.

Roberts, W. E.↗
NASA NTRS2008

Advances in Molten Oxide Electrolysis for the Production of Oxygen and Metals from Lunar Regolith

As part of an In-Situ Resource Utilization infrastructure to sustain long term-human presence on the lunar surface, the production of oxygen and metals by electrolysis of lunar regolith has been the subject of major scrutiny. There is a reasonably large body of literature characterizing the candidate solvent electrolytes, including ionic liquids, molten salts, fluxed oxides, and pure molten regolith itself. In the light of this information and in consideration of available electrolytic technologies, the authors have determined that direct molten oxide electrolysis at temperatures of approx 1600 C is the most promising avenue for further development. Results from ongoing studies as well as those of previous workers will be presented. Topics include materials selection and testing, electrode stability, gas capture and analysis, and cell operation during feeding and tapping.

Sadoway, Donald R.↗
NASA NTRS1973

Study and design of a cryogenic propellant acquisition system

The development of an acquisition system for supplying subcooled liquid hydrogen and liquid oxygen under in-orbit conditions is discussed. The system will be applied to the integrated cryogenic feed requirements for space systems such as a space shuttle cryogenic auxiliary propulsion system (APS) and main propulsion for an advanced spacecraft propulsion module (ASPM). Concepts that use the favorable surface tension characteristics of fine mesh screens are emphasized. The specific objectives of the program are: (1) to evolve conceptual designs for candidate acquisition systems, (2) to formulate the analytical models needed to analyze the systems, and (3) to generate parametric data on overall candidate system performance, characteristics, and operational features in sufficient depth to establish critical design problems and criteria to support a sound system design and evaluation.

Burge, G. W.↗
NASA NTRS1996

Flight control augmentation for AFT CG launch vehicles

The Space Shuttle was only the first step in achieving routine access to space. Recently, the NASA Marshall Space Flight Center (MSFC) has been studying a whole spectrum of new launch vehicles (L/V's) for space transportation. Some of these could transport components of the Space Station to orbit, and some could take us to Mars and beyond to boldly expand our frontiers of knowledge. In all our future launch vehicle (L/V) designs, decreasing the structural weight will always be of great concern. This is tantamount to increased payload capability, which in turn means reduced cost-per-pound to orbit. One very significant increase in payload capability has been defined. In a L/V recently studied at MSFC it has been shown that a sizable weight savings can be realized by a rearrangement of the internal propellant tanks. Studies have been conducted both at MSFC and at Martin Marietta Corporation, maker of the Space Shuttle External Tank (ET) which show that a very substantial weight can be saved by inverting the relative positions of the liquid hydrogen (LH2) and the liquid oxygen (LOX) propellant tanks in a particular L/V studied. As the vehicle sits on the launch pad, in the conventional configuration the heavier LOX tank is located on top of the lighter LH2. This requires a heavy structural member between the two tanks to prevent the lighter LH2 tank from being crushed. This configuration also requires large, long, and even drag producing LOX feed lines running the length of the vehicle on the exterior fuselage. If the relative position of the propellant tanks is inverted, both the heavy structural separation member and the long LOX feed lines could be deleted. While the structures community at MSFC was elated with this finding, the LOX tank aft configuration gave the vehicle an aft center-of-gravity (cg) location which surfaced controllability concerns. In the conventional configuration the L/V is controlled in the ascent trajectory by the gimballing of its rocket engines. Studies have been conducted at MSFC which showed that the resulting aft cg configured L/V would not be adequately controllable with the engine gimballing alone.

Barret, Chris↗
NASA NTRS1978

Arc termination cracks in Inconel 718 and Incoloy 903

The welding of the nickel base, heat resistant alloys that are used extensively for welded Shuttle engine components revealed solidification cracking characteristics at weld termination points. If not detected and removed, these crater cracks may cause costly component failure. To better understand this characteristic, welding termination techniques were studied and methods developed to eliminate crater cracks. It was determined that weld termination solidification cracking can be eliminated by controlled decrease of welding current, welding voltage, wire feed, and travel speed.

Bayless, E.↗
NASA NTRS1982

Molecular-beam sampling study of extinguishment of methane-air flames by dry chemicals

The use of Al2O3, NaHCO3, KHCO3, NH4H2PO4 and KCl powders for the inhibition of a methane/oxygen diffusion flame is studied through measurement of composition and temperature profiles, using a molecular beam mass spectrometer sampling system. In order to obtain significant inhibition without extinguishing the flame, a powder feeding rate of 2 mg/liter of gas was used for KCl and Al2O3, and of 3 mg/liter of gas for the remaining powders. CH4, O2, N2, H2O and CO2 concentrations were measured by the mass spectrometer, while temperature was measured by the time-of-flight technique. For the powder feeding rates used, Al2O3 was the least and KCl and NH2H4PO2 the most effective in reducing temperature; in reaction-inhibition effectiveness, Al2O3 was again lowest while KCl was superior to all others. Because the KCl concentration was only 2/3 that of NH4H2PO4, it is recommended as the most effective temperature reducer and reaction inhibitor.

Knuth, E. L.↗