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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 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
NASA NTRS1989

Low temperature testing of Li-SOCl2 cells

The performance and safety characteristics Li-SOCl2 cells were evaluated at -40 C. Tests were conducted on cells of several defferent designs to determine the influence of cell design on performance and safety. The cells exhibited low operating voltages, poor voltage regulation, and low capacity at -40 C. The performance of the cells was found to be critically dependent on the cell design. No safety problems were observed during discharge to 2.0 V under constant current and constant load operating conditions. Cells subjected to prolonged periods of continuous drain at constant-load did not vent/rupture upon warm-up. Cells subjected to prolonged reversal were found to be potentially hazardous. Microcalorimetry and electrochemical impedance spectroscopy studies performed on the cells suggested that those containing a catalyst may exhibit poor shelf life.

Subbarao, S.↗
NASA NTRS1990

Low temperature performance of lithium/silver vanadium oxide cells

Lithium/silver vanadium oxide cells for low temperature applications have been developed. Prismatic and spirally wound AA cells were tested under constant load discharge of 0.3 to 1.8 amps or pulse discharge of 0.225 or 1.0 amps at temperatures from -40 to 25 C. At -40 C with current densities of 2.5 mA/cm2, 23 percent of theoretical capacity was achieved under constant load discharge and 40 percent of theoretical capacity was achieved under pulse test. Self-discharge estimates of 0.7 percent per year at 25 C were obtained from microcalorimetry. Preliminary safety testing of the cells revealed no violent performance under short circuit or crush tests.

Takeuchi, E. S.↗
NASA NTRS1991

Improved Li-TiS2 cell cycling in ether-based electrolytes with synergistic additives

Results of the application of 2-MeF and KOH additives to improve the lithium stability in THF, dioxolane, and THF/2-MeTHF solvent-based electrolytes are presented. The stability of these electrolytes with and without additives is evaluated by microcalorimetry and AC impedance spectroscopy. A novel method, cathode turnover number, is proposed to represent the electrolyte performance in a given system. The lithium cycling efficiency and cathode turnover number of the electrolytes are calculated from the cycle life data in experimental Li-TiS2 cells. Overall, THF/2-MeTHF electrolyte containing 2-MeF and/or KOH exhibited higher stability, lithium cycling efficiency, and cathode turnover number compared to THF and dioxolane electrolytes with and without additives.

Shen, D. H.↗
NASA NTRS1991

Improved Li/TiS2 cell cycling in ether-based electrolytes with synergistic additives

Based on an extensive series of normalized full cell Li/TiS2 cycling studies, open-circuit storage tests, microcalorimetry and AC impedance studies, and chemical precedent, we propose an integrated chemical model consistent with experimental observations concerning the behavior of numerous LiAsF6/cyclic ether electrolytes. The particularly striking potency of certain additives such as 2-methylfuran and the hydroxide action resides in their ability to intercept several different adverse catalytic processes concurrently in the bulk electrolyte as well as the Li anode and TiS2 cathode.

Dominey, L. A.↗
NASA NTRS1993

Lithium D-cell study

The purpose of this contract is to evaluate parametrically the effects of various factors including the electrolyte type, electrolyte concentration, depolarizer type, and cell configuration on lithium cell electrical performance and safety. This effort shall allow for the selection and optimization of cell design for future NASA applications while maintaining close ties with WGL's continuous improvements in manufacturing processes and lithium cell design. Taguchi experimental design techniques are employed in this task, and allow for a maximum amount of information to be obtained while requiring significantly less cells than if a full factorial design were employed. Acceptance testing for this task is modeled after the NASA Document EP5-83-025, Revision C, for cell weights, OCV's and load voltages. The performance attributes that are studied in this effort are fresh capacity and start-up characteristics evaluated at two rates and two temperatures, shelf-life characteristics including start-up and capacity retention, and iterative microcalorimetry measurements. Abuse testing includes forced over discharge at two rates with and without diode protection, temperature tolerance testing, and shorting tests at three rates with the measurement of heat generated during shorting conditions.

Size, P.↗
NASA NTRS1996

Thermal Optimization of Growth and Quality in Protein Crystals

Experimental evidence suggests that larger and higher quality crystals can be attained in the microgravity of space; however, the effect of growth rate on protein crystal quality is not well documented. This research is the first step towards providing strategies to grow crystals under constant rates of growth. Controlling growth rates at a constant value allows for direct one-to-one comparison of results obtained in microgravity and on earth. The overall goal of the project was to control supersaturation at a constant value during protein crystal growth by varying temperature in a predetermined manner. Applying appropriate theory requires knowledge of specific physicochemical properties of the protein solution including the effect of supersaturation on growth rates and the effect of temperature on protein solubility. Such measurements typically require gram quantities of protein and many months of data acquisition. A second goal of the project applied microcalorimetry for the rapid determination of these physicochemical properties using a minimum amount of protein. These two goals were successfully implemented on hen egg-white lysozyme. Results of these studies are described in the attached reprints.

Wiencek, John M.↗
NASA NTRS1993

JSC Director's Discretionary Fund 1992 Annual Report

Annual report of the Johnson Space Center Director's Discretionary Fund documenting effective use of resources. The $1,694,000 funding for FY92 was distributed among 27 projects. The projects are an overall aid to the NASA mission, as well as providing development opportunities for the science and engineering staff with eventual spinoff to commercial uses. Projects described include space-based medical research such as the use of stable isotopes of deuterium and oxygen to measure crew energy use and techniques for noninvasive motion sickness medication. Recycling essentials for space crew support is conducted in the Regenerative Life Support and the Hybrid Regenerative Water Recovery test beds. Two-phase fluid flow simulated under low-gravity conditions, hypervelocity particle impact on open mesh bumpers, and microcalorimetry to measure the long-term hydrazine/material compatibility were investigated. A patent application was made on a shape-memory-alloy release nut. Computer estimate of crew accommodations for advanced concepts was demonstrated. Training techniques were evaluated using multimedia and virtual environment. Upgrades of an electronic still camera provide high resolution images from orbit are presented.

Jenkins, Lyle↗
NASA NTRS1998

Development of Ultra Low Temperature, Impact Resistant Lithium Battery for the Mars Microprobe

The requirements of the power source for the Mars Microprobe, to be backpacked on the Mars 98 Spacecraft, are fairly demanding, with survivability to a shock of the order of 80,000 g combined with an operational requirement at -80 C. Development of a suitable power system, based on primary lithium-thionyl chloride is underway for the last eighteen months, together with Yardney Technical Products Inc., Pawcatuck, CT. The battery consists of 4 cells of 2 Ah capacity at 25 C, of which at least 25 % would be available at -80 C, at a moderate rate of C/20. Each probe contains two batteries and two such probes will be deployed. The selected cell is designed around an approximate 1/2 "D" cells, with flat plate electrodes. Significant improvements to the conventional Li-SOCl2 cell include: (a) use of tetrachlorogallate salt instead of aluminate for improved low temperature performance and reduced voltage delay, (b) optimization of the salt concentration, and (c) modification of the cell design to develop shock resistance to 80,000 g. We report here results from our several electrical performance tests, mission simulation tests, microcalorimetry and AC impedance studies, and Air gun tests. The cells have successfully gone through mission-enabling survivability and performance tests for the Mars Microprobe penetrator.

Frank, H.↗
NASA NTRS2000

Thermal Stability of Otto Fuel Prepolymer

Otto Fuel II contains a nitrate ester, plasticizer, and 2-NPDA as a stabilizer. Otto Fuel with stabilizers from three vendors was investigated by dynamic and isothermal differential scanning calorimetry (DSC) using samples sealed in a glass ampoule and by Isothermal Microcalorimetry (IMC) using 10 gram samples aged at 75 C for 35 days. DSC kinetics did not show differences between the stabilizer; the samples had an activation energy of 36.7 +/- 0.6 kcal/mol. However, IMC analysis was sensitive enough to detect small differences between the stabilizer, namely energy of interaction values of 7 to 14 Joules. DSC controlled cooling and heating at 5 C/min from 30 to -60 to 40 C experiments were similar and showed a crystallization peak at -48 +/- 1 C during cooling, and upon heating there was a glass transition temperature step at approx. -54 +/- 0.5 C and a melting peak at -28 +/- 0.4 C.

Tompa, Albert S.↗
NASA NTRS2000

Thermal Stability of Otto Fuel Prepolymer

Otto Fuel II contains a nitrate ester, plasticizer, and 2-NDPA as a stabilizer. Otto Fuel with stabilizers from three vendors was investigated by dynamic and isothermal DSC using samples sealed in a glass ampoule and by Isothermal Microcalorimetry (IMC) using 10 gram samples aged at 75 C for 35 days. DSC kinetics did not show differences between the stabilizer; the samples had an activation energy of 36.7 +/- 0.6 kcal/mol. However, IMC analysis was sensitive enough to detect small differences between the stabilizer, namely energy of interaction values of 7 to 14 Joules. DSC controlled cooling and heating at 5 C/min from 30 to -60 to 40 C experiments were similar and showed a crystallization peak at -48 +/- 1 C during cooling, and upon heating there was a glass transition temperature step at approx. -54 +/- 0.5 C and a melting peak at -28 +/- 0.4 C.

Tompa, Albert S.↗
NASA NTRS2000

Assessment of The Compatibility of Composite Materials With High-Test Hydrogen Peroxide

The compatibility of composite materials with high-test hydrogen peroxide (HTP) was assessed using various chemical and mechanical techniques. Methods included classical schemes combining concentration assay with accelerated aging by means of a heated water bath. Exothermic reactivity was observed using Isothermal Microcalorimetry. Mechanical Properties testing determined degradation of the composite material. Photoacoustic Infrared Spectroscopy was used to monitor chemical alteration of the resin matrix. Other materials were examined including some polymers and metals.

Gostowski, Rudy↗
NASA NTRS2001

Further Studies of Materials Compatibility in High-Test Hydrogen Peroxide

Assessment of the compatibility of high-test hydrogen peroxide (HTP) with materials, in particular new materials such as composites, is critical to the development of new propulsion systems meeting requirements of reduced cost and environmental impact. While compatibility with HTP has been addressed previously, newer materials were not considered. The focus of this project was to develop a scheme for evaluation of HTP with all materials. In the previous summer, methods were developed for production of HTP on site, and preliminary steps were taken to evaluate materials. Methods investigated this summer have included accelerated aging by heating, coupled with assay of concentration and stabilization loss, observation of reactivity by means of Isothermal Microcalorimetry, and evaluation of changes to the materials by Short Beam Shear testing and by Photoacoustic-Fourier Transform Infrared Spectroscopy. Various metals, polymers, and composites were examined in this study.

Gostowski, R.↗
NASA NTRS2002

Compatibility Studies of Hydrogen Peroxide and a New Hypergolic Fuel Blend

Several preliminary materials compatibility studies have been conducted to determine the practicality of a new hypergolic fuel system. Hypergolic fuel ignites spontaneously as the oxidizer decomposes and releases energy in the presence of the fuel. The bipropellant system tested consists of high-test hydrogen peroxide (HTP) and a liquid fuel blend consisting of a hydrocarbon fuel, an ignition enhancer and a transition metal catalyst. In order for further testing of the new fuel blend to take place, some basic materials compatibility and HTP decomposition studies must be accomplished. The thermal decomposition rate of HTP was tested using gas evolution and isothermal microcalorimetry (IMC). Materials were analyzed for compatibility with hydrogen peroxide including a study of the affect welding has on stainless steel elemental composition and its relation to HTP decomposition. Compatibility studies of valve materials in the fuel blend were performed to determine the corrosion resistance of the materials.

Baldridge, Jennifer↗
NASA NTRS2003

Isothermal Microcalorimetric Evaluation of Compatibility of Proposed Injector Materials with High-Test Hydrogen Peroxide Propellant

High-test hydrogen peroxide (HTP) is receiving renewed interest as a monopropellant and as the oxidizer for bipropellant systems. HTP is hydrogen peroxide in concentrations ranging from 70 to 98%. All surfaces wetted by HTP must be evaluated for compatibility with the fluid. In the case of tanks, lines and valves compatibility is required to preserve the HTP oxygen and energy content and to avoid overpressurization due to decomposition. With injectors and regenerative cooling passages shorter exposure time reduces these concerns. However, phase changes from fluid to gas impact heat transfer and become the dominant compatibility concern. Isothermal microcalorimetry (IMC) provides a convenient and reproducible means to observe the decomposition of HTP when exposed to structural materials and therefore the compatibility of those materials'. The instrument provides heat flow values in terms of watts that may be converted to a reaction rate given the heat of reaction for the decomposition of hydrogen peroxide. These values are then converted to percent active oxygen loss per week (%AOL/wk) to preserve an earlier convention for quantifying HTP compatibility. Additionally, qualitative designations of compatibility have been assigned to these values. This scheme consists of four classes with Class 1 being the most compatible. While historical compatibility data is available its current applicability is in question due to subtle changes in the compositions of both HTP and structural materials. Trace levels of molecules can have significant influence on compatibility. Therefore representative samples of materials must be evaluated with current HTP formulations. In this work seven materials were selected for their strength characteristics at high temperature as expected in a HTP injector. The materials were then evaluated by IMC for HTP compatibility.

Gostowski, Rudy↗
NASA NTRS2004

Nonlinear Acoustical Assessment of Precipitate Nucleation

The purpose of the present work is to show that measurements of the acoustic nonlinearity parameter in heat treatable alloys as a function of heat treatment time can provide quantitative information about the kinetics of precipitate nucleation and growth in such alloys. Generally, information on the kinetics of phase transformations is obtained from time-sequenced electron microscopical examination and differential scanning microcalorimetry. The present nonlinear acoustical assessment of precipitation kinetics is based on the development of a multiparameter analytical model of the effects on the nonlinearity parameter of precipitate nucleation and growth in the alloy system. A nonlinear curve fit of the model equation to the experimental data is then used to extract the kinetic parameters related to the nucleation and growth of the targeted precipitate. The analytical model and curve fit is applied to the assessment of S' precipitation in aluminum alloy 2024 during artificial aging from the T4 to the T6 temper.

Cantrell, John H.↗
NASA NTRS2007

Absorber Materials for Transition-Edge Sensor X-ray Microcalorimeters

Arrays of superconducting transition-edge sensors (TES) can provide high spatial and energy resolution necessary for x-ray astronomy. High quantum efficiency and uniformity of response can be achieved with a suitable absorber material, in which absorber x-ray stopping power, heat capacity, and thermal conductivity are relevant parameters. Here we compare these parameters for bismuth and gold. We have fabricated electroplated gold, electroplated gold/electroplated bismuth, and evaporated gold/evaporated bismuth 8x8 absorber arrays and find that a correlation exists between the residual resistance ratio (RRR) and thin film microstructure. This finding indicates that we can tailor absorber material conductivity via microstructure alteration, so as to permit absorber thermalization on timescales suitable for high energy resolution x-ray microcalorimetry. We show that by incorporating absorbers possessing large grain size, including electroplated gold and electroplated gold/electroplated bismuth, into our current Mo/Au TES, devices with tunable heat capacity and energy resolution of 2.3 eV (gold) and 2.1 eV (gold/bismuth) FWHM at 6 keV have been fabricated.

Brown, Ari-David↗
NASA NTRS2012

NASA Tech Briefs, August 2012

Topics covered include: Mars Science Laboratory Drill; Ultra-Compact Motor Controller; A Reversible Thermally Driven Pump for Use in a Sub-Kelvin Magnetic Refrigerator; Shape Memory Composite Hybrid Hinge; Binding Causes of Printed Wiring Assemblies with Card-Loks; Coring Sample Acquisition Tool; Joining and Assembly of Bulk Metallic Glass Composites Through Capacitive Discharge; 670-GHz Schottky Diode-Based Subharmonic Mixer with CPW Circuits and 70-GHz IF; Self-Nulling Lock-in Detection Electronics for Capacitance Probe Electrometer; Discontinuous Mode Power Supply; Optimal Dynamic Sub-Threshold Technique for Extreme Low Power Consumption for VLSI; Hardware for Accelerating N-Modular Redundant Systems for High-Reliability Computing; Blocking Filters with Enhanced Throughput for X-Ray Microcalorimetry; High-Thermal-Conductivity Fabrics; Imidazolium-Based Polymeric Materials as Alkaline Anion-Exchange Fuel Cell Membranes; Electrospun Nanofiber Coating of Fiber Materials: A Composite Toughening Approach; Experimental Modeling of Sterilization Effects for Atmospheric Entry Heating on Microorganisms; Saliva Preservative for Diagnostic Purposes; Hands-Free Transcranial Color Doppler Probe; Aerosol and Surface Parameter Retrievals for a Multi-Angle, Multiband Spectrometer LogScope; TraceContract; AIRS Maps from Space Processing Software; POSTMAN: Point of Sail Tacking for Maritime Autonomous Navigation; Space Operations Learning Center; OVERSMART Reporting Tool for Flow Computations Over Large Grid Systems; Large Eddy Simulation (LES) of Particle-Laden Temporal Mixing Layers; Projection of Stabilized Aerial Imagery Onto Digital Elevation Maps for Geo-Rectified and Jitter-Free Viewing; Iterative Transform Phase Diversity: An Image-Based Object and Wavefront Recovery; 3D Drop Size Distribution Extrapolation Algorithm Using a Single Disdrometer; Social Networking Adapted for Distributed Scientific Collaboration; General Methodology for Designing Spacecraft Trajectories; Hemispherical Field-of-View Above-Water Surface Imager for Submarines; and Quantum-Well Infrared Photodetector (QWIP) Focal Plane Assembly.

Source record↗
NASA NTRS2015

Heat Capacity and Thermal Conductance Measurements of a Superconducting-Normal Mixed State by Detection of Single 3 eV Photons in a Magnetic Penetration Thermometer

We report on measurements of the detected signal pulses in a molybdenum-gold Magnetic Penetration Thermometer (MPT) in response to absorption of one or more 3 eV photons. We designed and used this MPT sensor for x-ray microcalorimetry. In this device, the diamagnetic response of a superconducting MoAu bilayer is used to sense temperature changes in response to absorbed photons, and responsivity is enhanced by a Meissner transition in which the magnetic flux penetrating the sensor changes rapidly to minimize free energy in a mixed superconducting normal state. We have previously reported on use of our MPT to study a thermal phonon energy loss to the substrate when absorbing x-rays. We now describe results of extracting heat capacity C and thermal conductance G values from pulse height and decay time of MPT pulses generated by 3 eV photons. The variation in C and G at temperatures near the Meissner transition temperature (set by an internal magnetic bias field) allow us to probe the behavior in superconducting normal mixed state of the condensation energy and the electron cooling power resulting from quasi-particle recombination and phonon emission. The information gained on electron cooling power is also relevant to the operation of other superconducting detectors, such as Microwave Kinetic Inductance Detectors.

superconductivity↗