Wash efficiency tests
Processed film products were tested for residual thiosulfate by precipitation as colored silver sulfide. The quantity of thiosulfate was determined and correlated with the expected storage life of the film.
Maas, K. A.↗
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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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Review of machine washing efficiency for original film
Further silver sulfide stain tests for wash efficiency were conducted with major emphasis on means by which archival keeping quality may be achieved for original mission film.
Maas, K. A.↗
Identification and interpretation of tectonic features from Skylab imagery
The author has identified the following significant results. A remarkable system of northwest and west-northwest trending faults was found to continue from eastern California into southwestern Arizona. The most significant is a fault belt which extends from west of Marble Mountains (southeastern California) across the Colorado River at Parker Valley towards Silver Bell Mountains, southern Arizona.
Abdel-Gawad, M.↗
A simple method for estimation of coagulation efficiency in mixed aerosols
Aerosols of KBr and AgNO3 were mixed, exposed to light in a glass tube and collected in the dark. About 15% of the collected material was reduced to silver upon development. Thus, two aerosols of particles that react to form a photo-reducible compound can be used to measure coagulation efficiency.
Dimmick, R. L.↗
Evaluation of wet tantalum capacitors after exposure to extended periods of ripple current, volume 2
The application of tantalum capacitors in the Viking Lander includes dc voltage and ripple current electrical stress, high temperature during nonoperating times (sterilization), and high vibration and shock loads. The capacitors must survive these severe environments without any degradation if reliable performance is to be achieved. A test program was established to evaluate both wet-slug tantalum and wet-foil capacitors under conditions accurately duplicating actual Viking applications. Test results of the electrical performance characteristics during extended periods of ripple current, the characteristics of the internal silver migration as a function of extended periods of ripple current, and the existence of any memory characteristics are presented.
Ward, C. M.↗
Factors influence flexibility resistivity and zinc dendrite penetration rate of inorganic separators for alkaline batteries
Developmental work resulted in a formulation which can improve the flexibility of the inorganic-organic-type separator for silver-zinc and nickel-zinc alkaline batteries. The effects of various fillers and reactive organic additives on separator volume resistivity are described. The effects of various inert fillers on the zinc dendrite penetration rate of the separator are shown. Conclusions regarding the operating mechanism of the separator are presented.
Sheibley, D. W.↗
The 1973 GSFC battery workshop, second day
Technological progress in the development, testing, and manufacturing of nickel-cadmium battery cells as well as hydrogen cells is presented. The following major topics were discussed: (1) carbonate analysis; (2) nickel-cadmium memory effect; (3) use of batteries in an automatic acquisition and control system; (4) accelerated testing; (5) formulation of a mathematical odel for a nickel-cadmium cell; (6) development of a light weight nickel-cadmium battery capable of delivering 20 watt hours per pound; (7) magnetic testing of nickel-cadmium cells; (8) design and performance characteristics of nickel-hydrogen and silver-hydrogen cells; and (9) development of a semiprismatic cell design. For Vol. 1, see N75-15152.
Source record↗
Long-distance recording of the humidity over the sea
A procedure is developed for long distance recording of humidity over the sea that uses humidity detectors of the sorption type, whose electrical properties depend on the relative humidity of the air. The moisture sensitive material of the hygristor is the organic polymer polyacrylonitryl, deposited on silver electrodes and thermally treated. In the measurements of the relative humidity from 60% to 95%, the resistance of the hygristor varies from several hundred kiloohms to a few kiloohms, and is an essentially nonlinear function of the humidity.
Buklanov, V. V.↗
Ultrasonically bonded value assembly
A valve apparatus capable of maintaining a fluid-tight seal over a relatively long period of time by releasably bonding a valve member to its seat is described. The valve member is bonded or welded to the seat and then released by the application of the same energy to the bond joint. The valve member is held in place during the bonding by a clamping device. An appropriate force device can activate the opening and closing of the valve member. Various combinations of material for the valve member and valve seat can be utilized to provide an adequate sealing bond. Aluminum oxide, stainless steel, inconel, tungsten carbide as hard materials and copper, aluminum, titanium, silver, and gold as soft materials are suggested.
Salvinski, R. J.↗
Emission spectrometric arcing procedure with minimal effect of chemical form of sample
Matrix effects related to the chemical form of analyzed materials were studied. An arc in argon was used which was buffered with silver chloride. The effect of chemical form was minimal for a variety of metals, oxides, and carbides representing the most refractory compounds and thermally stable metal-containing molecules. Only four of the most refractory materials known showed significant emission depressions due to incomplete volatilization in the arc system. These results are discussed in terms of vapor pressures of the solid materials placed on the anodes and dissociation reactions of the molecules in the gaseous environment.
Gordon, W. A.↗
Experiment definition phase shuttle laboratory: LDRL-10.6 experiment
Progress is reported in the development of the space shuttle laboratory laser data relay link. The system transmittance of various surfaces was considered in order to examine the coating tradeoffs for the beryllium mirrors. The results of six coating combinations considered are summarized. It is recommended that silver coatings be used throughout the system. Design of the pre-expander and a preliminary alignment procedure implemented to align all optical elements to the reference mechanical axis (the rotational axis of the outer gimbal bearing located between the two Gregorian telescopes) are included. The local oscillator subsystem, consisting of the laser, Stark cell, Stark cell electronics, power supply, starting circuit, and conditioning optics were completed and installed in the optimechanical subsystem and operation against a 10.6 micrometer source was attempted. Preliminary measurements of the HgCdTe mixer showed that this critical element was inoperative and in subsequent tests the receiver front end electronics had also failed. Possible reasons for these failures and corrective action and steps to prevent future recurrence are discussed.
Source record↗
Thrust chamber life prediction. Volume 1: Mechanical and physical properties of high performance rocket nozzle materials
Pertinent mechanical and physical properties of six high conductivity metals were determined. The metals included Amzirc, NARloy Z, oxygen free pure copper, electroformed copper, fine silver, and electroformed nickel. Selection of these materials was based on their possible use in high performance reusable rocket nozzles. The typical room temperature properties determined for each material included tensile ultimate strength, tensile yield strength, elongation, reduction of area, modulus of elasticity, Poisson's ratio, density, specific heat, thermal conductivity, and coefficient of thermal expansion. Typical static tensile stress-strain curves, cyclic stress-strain curves, and low-cycle fatigue life curves are shown. Properties versus temperature are presented in graphical form for temperatures from 27.6K (-410 F) to 810.9K (1000 F).
Esposito, J. J.↗
Direct observation of small cluster mobility and ripening
Direct evidence is reported for the simultaneous occurrence of Ostwald ripening and short-distance cluster mobility during annealing of discontinuous metal films on clean amorphous substrates. The annealing characteristics of very thin particulate deposits of silver on amorphized clean surfaces of single crystalline thin graphite substrates were studied by in-situ transmission electron microscopy (TEM) under controlled environmental conditions (residual gas pressure of 10 to the minus 9th power torr) in the temperature range from 25 to 450 C. Sputter cleaning of the substrate surface, metal deposition, and annealing were monitored by TEM observation. Pseudostereographic presentation of micrographs in different annealing stages, the observation of the annealing behavior at cast shadow edges, and measurements with an electronic image analyzing system were employed to aid the visual perception and the analysis of changes in deposit structure recorded during annealing. Slow Ostwald ripening was found to occur in the entire temperature range, but the overriding surface transport mechanism was short-distance cluster mobility.
Heinemann, K.↗
Photoelectron emission analysis of surface elements of the International Sun Earth Explorer
The photoemission was measured of engineering materials (aluminum; copper, plain; copper, abraded; copper-beryllium; magnesium; silver; In2O3 on silica; reflective coating on silica; teflon; kapton; and Pyre ML) associated with the International Sun Earth Explorer (ISEE) Satellite. The procedures used are described, including the experimental equipment; results of the program, the conclusions reached, and areas for further work are presented. Data regarding the measured yield of the 11 materials whose surface emission was determined is included in the form of plots of photoelectric yield versus incident light wavelength.
Spencer, W. T.↗
Plasma-sprayed, self-lubricating coatings for use from cryogenic temperatures to 870 deg C (1600 deg F)
A plasma-sprayed coating is described with good lubricating properties over a wide temperature range. The coating, designated NASA LUBE PS101, contains silver, nichrome, calcium fluoride, and an oxidation protective glass. Oscillating tests were conducted of self-aligning, plain cylindrical bearings, in which the bore was lined with 0.025 cm (0.010 in.) thick coatings of PS101; these were conducted at a radial load of 3.5 x 10 to the 7th power N/sq m (5000 psi) in nitrogen gas at -107 C (-160 F), in vacuum at room temperature, and in air from room temperature to 870 C (1600 F). Friction coefficients were less than 0.25 in all cases and wear rates were low. The coating is not brittle, and it has adequate oxidation resistance in air to at least 870 C.
Sliney, H. E.↗
Properties criteria for components and materials used in lightweight solar arrays
The present work describes the characteristics and design criteria for components and materials used in lightweight substrate solar arrays. This includes descriptions of wraparound-electrode solar cells, cell covers, and cell interconnects. Cell cover systems briefly discussed are fused silica, cerium stabilized glass, microsheet, FEP (tape, heat laminated, and spray on), and ESB 7070 glass integral covers. The majority of solar arrays orbited have used either silver, Kovar, copper, or molybdenum as interconnect metals. Data are presented comparing the Young's modulus E, ultimate tensile strength, coefficient of expansion, thermal conductivity, and percent elongation of these and other interconnect candidate materials. Guidelines for the use of end tab wraparound cells are listed.
Lott, D. R.↗
Nodular growth in thick-sputtered metallic coatings
Thick-sputtered S-Monel, silver, and 304 stainless steel coatings were deposited on mica and metal substrates with various surface finishes to investigate the nodular growth in the coating by scanning electron microscopy. The geometry and the surface structure of the nodules are characterized. Compositional changes within the coating were analyzed by energy dispersive X-ray analysis. Defects in the surface finish (i.e., scratches, inclusions, etc.), act as preferential nucleation sites and form isolated and complex nodules and various surface overgrowths in the coating. The nodule boundaries are very vulnerable to chemical etching and these nodules do not disappear after full annealing. Further, they have undesirable effects on mechanical properties; cracks are initiated at the nodules when the coating is stressed by mechanical forces. These effects are illustrated by micrographs. Nodular growth within a coating can be minimized or eliminated by increasing the surface smoothness.
Spalvins, T.↗
Ovonic type switching in tin selenide thin films
Amorphous tin selenide thin films which possess Ovonic type switching properties are fabricated using vacuum deposition techniques. The devices are fabricated in a planar configuration and consist of amorphous tin selenide deposited over silver contacts. Results obtained indicate that Ovonic type memory switching does occur in these films with the energy density required for switching from a high impedance to a low impedance state being dependent on the spacing between the electrodes of the device. There is also a strong implication that the switching is a function of the magnitude of the applied voltage pulse.
Baxter, C. R.↗