Search NASA⌕ Search

SEARCH · Search NASA

Results for “GLASS COATING”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 145 records · Page 8

Status of the NASA-Lewis flat-plate collector tests with a solar simulator

Simulator test results of 15 collector types are presented. Collectors are given performance ratings according to their use for pool heating, hot water, absorption A/C or heating, and solar Rankine machines. Collectors found to be good performers in the above categories, except for pool heating, were a black nickel coated, 2 glass collector, and a black paint 2 glass collector containing a mylar honeycomb. For pool heating, a black paint, one glass collector was found to be the best performer. Collector performance parameters of 5 collector types were determined to aid in explaining the factors that govern performance. The two factors that had the greatest effect on collector performance were the collector heat loss and the coating absorptivity.

Simon, F. F.↗

Status of the NASA-Lewis flat-plate collector tests with a solar simulator

Simulator test results of 15 collector types are reported. Collectors are given performance ratings according to their use for pool heating, hot water, absorption A/C or heating and solar Rankine machines. Collectors found to be good performers in the above categories, except for pool heating, were a black nickel coated, 2 glass collector, and a black paint 2 glass collector containing a mylar honeycomb. For pool heating, a black paint, one glass collector was found to be the best performer. Collector performance parameters of 5 collector types were determined to aid in explaining the factors that govern performance. The two factors that had the greatest effect on collector performance were the collector heat loss and the coating absorptivity.

Simon, F. F.↗

Raman spectra of adsorbed layers on space shuttle and AOTV thermal protection system surface

Surfaces of interest to space vehicle heat shield design were struck by a 2 W argon ion laser line while subjected to supersonic arc jet flow conditions. Emission spectra were taken at 90 deg to the angle of laser incidence on the test object. Results showed possible weak Raman shifts which could not be directly tied to any particular parameter such as surface temperature or gas composition. The investigation must be considered exploratory in terms of findings. Many undesirable effects were found and corrected as the project progressed. For instance, initial spectra settings led to ghosts which were eliminated by closing the intermediate of filter slit of the Spex from 8 to 3 mm. Further, under certain conditions, plasma lines from the laser were observed. Several materials were also investigated at room temperature for Raman shifts. Results showed Raman shifts for RCC and TEOS coated materials. The HRSI materials showed only weak Raman shifts, however, substantial efforts were made in studying these materials. Baseline materials showed the technique to be sound. The original goal was to find a Raman shift for the High-temperature Reusable Surface Insulation (HRSI) Reaction Cured borosilicate Glass (RCG) coated material and tie the amplitude of this peak to Arc jet conditions. Weak Raman shifts may be present, however, time limitations prevented confirmation.

Willey, Ronald J.↗

Transparent switchboard

A tin oxide coating is formed on a plate of glass and the coating is then etched away from the glass in thin lines to form separate electrical conductors which extend to one end of the plate and connect to either a vertical (column) or horizontal (row) position sensing SCR circuit. A thin transparent insulating coating is formed over the oxide layer except at selected touch points which are positioned in a matrix pattern of vertical columns and horizontal rows. Touching one of these points with a finger bridges the thin line between adjacent conductors to activate trigger circuits in the particular row and column sensing circuits associated with the point touched. The row and column sensing circuits are similar and are powered with a low frequency, ac voltage source. The source for the row circuits is 180 out of phase with the source for the column circuits so that one circuit acts as ground for the other during half of the supply voltage cycle. The signals from the sensing circuits are input to a logic circuit which determines the presence of a valid touch, stores a binary matrix number associated with the touched point, signals a computer of the presence of a stored number and prevents storage of a new number before receiving an enable signal from the computer.

Rasmussen, H. P.↗

High-Temperature Lubricants

In the early 1980's, Lewis Research Center began a program to develop high-temperature lubricants for use on future aircraft flying at three or more times the speed of sound, which can result in vehicle skin temperatures as high as 1,600 degrees Fahrenheit. A material that emerged from this research is a plasma-sprayed, self-lubricating metal- glass-fluoride coating able to reduce oxidation at very high temperatures. Technology is now in commercial use under the trade name Surf-Kote C-800, marketed by Hohman Plating and Manufacturing Inc. and manufactured under a patent license from NASA. Among its uses are lubrication for sliding contact bearings, shaft seals for turbopumps, piston rings for high performance compressors and hot glass processing machinery; it is also widely used in missile and space applications.

Source record↗

Assessing Degradation of Advanced Coatings for Carbon/Carbon Composites

Carbon/carbon (C/C) composites are a well-utilized material system for hot structures to enable hypersonic flight. However, C/C materials are susceptible to attack by environmental degradation mechanisms, notably oxidation, which can limit the durability of components resulting in premature failure. Environmental barrier coatings (EBCs) have been developed to mitigate deleterious oxidation. Coating compositions based on silicon carbide (SiC) offer promise as a protective coating material for C/C composites. Under particular hypersonic flight conditions, a passivating silica scale can form at the surface of the EBC, acting as a barrier that can protect the underlying coating and substrate. However, the transition from passive to active oxidation, which varies with temperature and pressure, causes the formation of gaseous SiO that volatilizes leading to detrimental consumption of the SiC coating. In this work, arc-jet testing of SiC-based coatings developed to protect Advanced C/C-6 (ACC-6) was performed under a range of conditions to replicate varying oxidation conditions. In-situ optical emission spectroscopic measurements of the gas-surface interactions were collected and evaluated to render compositional degradation of the coating and underlying composite during arc-jet testing. Specimens were evaluated before, during and after arc-jet testing using destructive and non-destructive materials characterization methods, including optical and scanning electron microscopy and energy dispersive spectroscopy.

Coatings, Hypersonics, Composites↗

Improved linings for integrating spheres

Sphere surface is covered with plain weave of glass fibers coated with polytetrafluoroethylene and one or two layers of magnesium oxide vapor. The resultant lining is suitable for measurement of radiation in the ultraviolet, visible, and near-infrared wavelengths, is not damage prone, and is easily cleaned.

Fergerson, P. O.↗

The Lick-Gaertner automatic measuring system

The Lick-Gaertner automatic equipment has been designed mainly for the measurement of stellar proper motions with reference to galaxies, and consists of two main components: the survey machine and the automatic measuring engine. The survey machine is used for initial inspection and selection of objects for subsequent measurement. Two plates, up to 17 x 17 inches each, are surveyed simultaneously by means of projection on a screen. The approximate positions of objects selected are measured by two optical screws: helical lines cut through an aluminum coating on glass cylinders. These approximate coordinates to a precision of the order of 0.03mm are transmitted to a card punch by encoders connected with the cylinders.

Vasilevskis, S.↗

Solar collector performance evaluation with the NASA-Lewis solar simulator-results for an all-glass-evacuated-tubular selectively-coated collector with a diffuse reflector

A solar collector was tested in a solar simulator for inlet temperatures of temperatures of 70 to 200 F, flux levels of 230 and rate of 7 lb/(hr)(sq. ft), and incident angles of 0 deg, 33 deg, and 52 deg. Test results plotted in a form suggested by analysis indicate a very low heat loss coefficient. The collector shows excellent performance on an all-day performance basis, and also for conditions corresponding to temperatures required in solar Rankine systems and/or for low flux level radiation.

Simon, F.↗

Lightweight reflector assembly

An inexpensive, lightweight reflective assembly member having good optical quality and particularly adaptable to accommodating temperature variations without providing destructive thermal stresses and reflective slope errors is described. The reflective assembly consists of a thin sheet of glass with appropriate reflective coating and a cellular glass block substrate bonded together. The method of fabrication includes abrading the cellular substrate with an abrasive master die to form an appropriate concave surface. An adhesive is applied to the abraded surface and a lamina reflective surface is placed under a uniform pressure to conform the reflective surface onto the desired abraded surface of the substrate.

Argoud, M. J.↗

Development and testing of a hot-air solar collector

Summarized report on development and testing of hot-air flat-plate solar collector includes structural details, coating selection, and spacing between coating and glass plate. Report gives complete performance specifications and extensive certifications test report.

Caudle, J. M.↗

Studies and testing of antireflective (AR) coatings for soda-lime glass

Processes for producing antireflection films on glass are concentrated in three areas: acid etching of glass, plasma etching of glass, and acid development of sodium silicate films on glass. The best transmission was achieved through the acid etching technique, while the most durable films were produced from development of sodium silicate films. Control of the acid etching technique is presently inadequate for production implementation. While films having excellent antireflective properties were fabricated by plasma etching techniques, all were water soluble.

Pastirik, E. M.↗

Petrology of 60035 - Evolution of a polymict ANT breccia

Extensive analysis of the lunar rock sample 60035 with optical microscopy and electron microprobe methods show it to be a polymict ANT breccia partly coated with glass, containing abundant clasts which have troctolitic/noritic anorthosite compositions. At least two episodes of crushing and mixing were involved in the petrogenesis of 60035, and annealing and mineral equilibration have not been extensive since the formation of the breccia.

Warner, R. D.↗

Antisoiling technology: Theories of surface soiling and performance of antisoiling surface coatings

Physical examination of surfaces undergoing natural outdoor soiling suggests that soil matter accumulates in up to three distinct layers. The first layer involves strong chemical attachment or strong chemisorption of soil matter on the primary surface. The second layer is physical, consisting of a highly organized arrangement of soil creating a gradation in surface energy from a high associated with the energetic first layer to the lowest possible state on the outer surfce of the second layer. The lowest possible energy state is dictated by the physical nature of the regional atmospheric soiling materials. These first two layers are resistant to removal by rain. The third layer constitutes a settling of loose soil matter, accumulating in dry periods and being removed during rainy periods. Theories and evidence suggest that surfaces that should be naturally resistant to the formation of the first two-resistant layers should be hard, smooth, hydrophobic, free of first-period elements, and have the lowest possible surface energy. These characteristics, evolving as requirements for low-soiling surfaces, suggest that surfaces or surface coatings should be of fluorocarbon chemistry. Evidence for the three-soil-layer concept, and data on the positive performance of candidate fluorocarbon coatings on glass and transparent plastic films after 28 months of outdoor exposure, are presented.

Cuddihy, E. F.↗

The LAMAR telescope module for high throughput imaging and spectroscopy

Kirkpatrick-Baez mirror assemblies for the LAMAR experiment of the Space Shuttle are described. The aperture is 20 cm x 30 cm and the distance from the front of the mirror to the focal plane is 3.4 m. The reflectors are made from 1.8 mm gold coated float glass. A prototype brassboard mirror was constructed with only one-third of the plates. Its angular resolution is 35 arcsec (HPW) in visible light. X-ray tests over small areas indicate very little scattering. The fabrication technique is applicable to larger mirror systems such as those of XMM. The use of flatter material for the reflectors results in better angular resolution.

Gorenstein, P.↗

X-ray telescope module for the LAMAR Space Shuttle experiment

The first of eight X-ray telescopes is under construction for the LAMAR experiment. Each consists of two orthogonal sets of nested confocal one-dimensional parabolic plates of gold-coated float glass, selected for flatness from commercial stock. Each is initially bent to a cylinder by bonding a thin, highly curved titanium sheet to its inactive surface. The final parabolic figure is produced by an automated system which includes seven diode arrays that detect a visible-light line image. Eight precise motorized linear translators operating under the control of a computer, tune the plate to the optimum figure. The plate is then fixed in position by epoxy bonds. The precision of the system is several arcsec, but the intrinsic flatness of the glass is expected to limit the half-power diameter (HPD) of the telescope to about 25 arcsec.

Gorenstein, P.↗