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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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Examples of zinc dust formulations, which are not subject to cracking or crazing, are fire retardant, and have high adhesive qualities, are listed. The potassium silicate in these formulations has mol ratios of dissolved silica potassium oxide in the range 4.8 to 1 - 5.3 to 1.
Feasibility of doping techniques for eliminating extraterrestrial solar degradation of ZnO used as pigment for spacecraft thermal control surfaces
Pigmented epoxy resin and silicone resin as white paint coatings for inflatable spacecraft
High energy particle and electromagnetic space radiation effects on thermal control coating, noting spectral absorptance for various conditions
Microminiature fuel cell design and tests, and gas discharge data on silver zinc cells
Performance test data on sealed assemblies of composite silver zinc cell and dual micro fuel cell
High energy particle and electromagnetic space radiation effects on thermal control coating, noting spectral absorptance for various conditions
Electron injection into ZnO from aqueous solutions of stable substances, correlating injection with oxidation potential of substance
UV irradiation effects on ZnO used as pigment for spacecraft thermal control coatings
Iron cyanide surface additives effect on photodamage to ZnO powder, using ESR method
Developing sealed silver-zinc cell for power supply on interplanetary spacecraft
A new kind of silver-zinc cell was developed and tested under NASA support which can withstand severe heat sterilization requirements and does not display the traditional life limiting aspect of sinc electrodes i.e. shape change. These cells could be used on planetary lander mission which require wet-stand periods of over a year, a modest number of cycles (400 to 500) and may require dry heat sterilization. The weight advantage of these cells over the traditional nickel cadmium batteries also makes it an attractive alternative for synchronous orbit service where 400 to 500 cycles would be required over a 5 year period.
A new kind of silver-zinc cell has been developed and tested under NASA support which can withstand severe heat sterilization requirements. These cells could be used on planetary lander mission which require wet-stand periods of over a year, a modest number of cycles (400 to 500) and may require dry heat sterilization. The weight advantage of these cells over the traditional nickel-cadmium batteries also makes it an attractive alternative for synchronous orbit service where 400 to 500 cycles would be required over a 5 year period.
A new kind of silver-zinc cell has been developed and tested under NASA support which can withstand severe heat sterilization requirements and does not display the traditional life limiting aspect of zinc electrodes - i.e., shape change. These cells could be used on a planetary lander mission which requires wet-stand periods of over a year, a modest number of cycles (400 to 500) and may require dry heat sterilization. The weight advantage of these cells over the traditional nickel-cadmium batteries makes them also an attractive alternative for synchronous orbit service where 400 to 500 cycles would be required over a five-year period.
Over 100 sealed AgO-Zn cells were subjected to prolonged periods of storage over a range of temperatures and storage modes including open circuit, trickle charge, and float charge. Impedances of these cells were monitored throughout, and at the end of the storage period their transient voltage characteristics were observed at the onset of discharge. Results revealed that the impedances of these cells tended to increase with storage time; the magnitude of the impedance rise was dependent primarily on temperature and to a lesser degree on storage mode. Typical values for 50 A-hr cells were usually less than 100 mohm immediately after activation and from 1 to 30 ohm after 6-10 months of storage. Transient voltages of these cells droped sharply during the first msec of discharge and then rose to a stablized value during the following few seconds. The magnitude of the initial drop and the stabilized voltage values were found to be related to impedance but not in a linear manner. The magnitude and duration of the low transient voltages may be unacceptable in some applications of these cells. The impedance variations are attributed to changes occurring at the positive electrode.
The objective of this work was to increase the interfacial strength between aramid fiber and epoxy matrix. This was achieved by functionalizing the aramid fiber followed by growth of a layer of ZnO nanowires on the fiber surface such that when embedded into the polymer, the load transfer and bonding area could be substantially enhanced. The functionalization procedure developed here created functional carboxylic acid surface groups that chemically interact with the ZnO and thus greatly enhance the strength of the interface between the fiber and the ZnO.
Spectroscopic methods are proposed for detection of thermal barrier coating (TBC) spallation from engine hot zone components. These methods include absorption and emission of airborne marker species originally embedded in the TBC bond coat. In this study, candidate marker materials for this application were evaluated. Thermochemical analysis of candidate marker materials combined with additional constraints such as toxicity and uniqueness to engine environment, provided a short list of four potential species: platinum, copper oxide, zinc oxide. and indium. The melting point of indium was considered to be too low for serious consideration. The other three candidate marker materials, platinum, copper oxide, and zinc oxide were placed in a high temperature furnace and emission and absorption properties were measured over a temperature range from 800-1400 C and a spectral range from 250 to 18000 nm. Platinum did not provide the desired response, likely due to the low vapor Pressure of the metallic species and the low absorption of the oxide species. It was also found, however. that platinum caused a broadening of the carbon dioxide absorption at 4300 nm. The nature of this effect is not known. Absorption and emission caused by sodium and potassium impurities in the platinum were found in the platinum tests. Zinc oxide did not provide the desired response, again, most likely due to the low vapor pressure of the metallic species and the low absorption of the oxide species. Copper oxide generated two strongly temperature dependent absorption peaks at 324.8 and 327.4 nm. The melting point of copper oxide was determined to be too low for serious consideration as marker material.
Design of silver oxide-zinc battery of limited cycle life with no degradation in discharge voltage characteristics