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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 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1980

Heat treat fixture and method of heat treating

A heat treating fixture is disclosed in which the shape of the metal specimen is maintained by cold rolled steel support plates. Glide sheets of stainless steel, coated with boron nitride, in contact with each face of the metal specimens, allow for lateral expansion of the metal specimens without binding. Grooved support bars separate the glide sheets from the upper and lower support plates and allow flow of quenching fluid to the metal specimen.

Beuyukian, C. S.↗
NASA NTRS1973

High tip speed fan inlet noise reduction using treated inlet splitters and accelerating inlets (quiet engine program fan C scale model)

A series of inlet suppression tests were run on a supersonic tip speed fan which employed an acoustically treated cowl wall, treated splitters and elevated average throat Mach numbers in various combinations. Results show appreciable fan noise reductions at high fan speeds; 15-18 PNdB. On the basis of inlet total pressure recovery loss per PNdb of noise reduction, an inlet with no splitters produced the most efficient design. However, greater reduction in noise was achieved with one splitter in the inlet. It was also noted that moderate increases in inlet Mach number increased noise in the acoustically treated inlets and that Mach numbers in excess of 0.65 were required before net noise reduction was realized.

Kazin, S. B.↗
NASA NTRS1973

Method of heat treating a formed powder product material

Heat treating a product material of prealloyed powders after shaping by superplastic deformation restores the ability of the material to resist deformation at high temperatures. Heat treating is accomplished by heating to a temperature between the solidus and liquidus with the application of isostatic pressure to close any voids. This pressure may be simultaneously applied while the material is at the heat treating temperature. The pressure may also be applied when the material cools to a temperature between that at which it is shaped and the solidus.

Freche, J. C.↗
NASA NTRS1972

Cytological studies of lunar treated tissue cultures

An electron microscopic study was made of botanical materials, particularly pine tissues, treated with lunar materials collected by Apollo 12 quarantine mission. Results show unusual structural changes within several of the treated tissues. The bodies, as yet unidentified, resemble virus particles observed within infected plant cells. Although the size and shape of the structures are comparable to rod shaped virus particles such as Tobacco mosaic, the numerical distribution, affinity for stains, and intercellular location are different.

Halliwell, R. S.↗
NASA NTRS1973

Annoyance judgements of aircraft with and without acoustically treated nacelles

A series of subjective response laboratory tests were conducted to determine the effectiveness of reducing aircraft noise by treating the aircraft engine nacelles with acoustically absorbent material. A total of 108 subjects participated in the magnitude estimation tests. The subjects were selected from persons who had previously been interviewed and classified according to selected psychological characteristics. The subjects lived in three general areas located at three specified distances from New York's Kennedy Airport. The aircraft signals used in the tests consisted of tape recordings of the landing approach noise of a B-727 aircraft under normal operating conditions. These recordings were electronically altered to simulate an aircraft with acoustically treated nacelles to achieve noise reductions of approximately 6 EPNdB and 12 EPNdB. The results from these tests indicate that significant reductions in annoyance resulted from the synthesized nacelle treatments.

Borsky, P. N.↗
NASA NTRS1974

The action of ultrasounds on Bezostaia 1 winter wheat grown in sand pots treated with Knop solution

The results of 3 years of research are presented concerning the increase in length and weight of the aerial biomass as compared with the underground biomass, as well as the productivity indexes of Bezostaia 1 winter wheat. The experiment involved two varieties, each of them with nine repetitions. Sterile sifted sand treated several times with a Knop solution during the vegetative period was used as a seed bed. The seeds were kept in water for 2 hours before treatment. Biometric and statistical measurements showed significant responses in the treated varieties.

Albu, N.↗
NASA NTRS1974

Effect of outdoor exposure at ambient and elevated temperatures on fatigue life of Ti-6Al-4V titanium alloy sheet in the annealed and the solution treated and aged condition

Specimens of Ti-6Al-4V titanium alloy sheet in the annealed and the solution-treated and aged heat-treatment condition were exposed outdoors at ambient and 560 K (550 F) temperatures to determine the effect of outdoor exposure on fatigue life. Effects of exposure were determined by comparing fatigue lives of exposed specimens to those of unexpected specimens. Two procedures for fatigue testing the exposed specimens were evaluated: (1) fatigue tests conducted outdoors by applying 1200 load cycles per week until failure occurred and (2) conventional fatigue tests (continuous cycling until failure occurred) conducted indoors after outdoor exposure under static load. The exposure period ranged from 9 to 28 months for the outdoor fatigue-test group and was 24 months for the static-load group. All fatigue tests were constant-amplitude bending of specimens containing a drilled hole (stress concentration factor of 1.6). The results of the tests indicate that the fatigue lives of solution-treated and aged specimens were significantly reduced by the outdoor exposure at 560 K but not by the exposure at ambient temperature. Fatigue lives of the annealed specimens were essentially unaffected by the outdoor exposure at either temperature. The two test procedures - outdoor fatigue test and indoor fatigue test after outdoor exposure - led to the same conclusions about exposure effects.

Phillips, E. P.↗
NASA NTRS1974

Effect of treated length on performance of full scale turbofan inlet noise suppressors

Two inlet noise suppressors containing wall treatment plus three treated rings were tested on a fan in an outdoor noise facility. Sound power attenuations were measured for three treated lengths of each suppressor. The noise reduction from the segment of liner closest to the fan, which contained a segment of wall treatment downstream of the splitter rings, was greater than the reduction from either of the other segments. The decibel attenuations of the ringed liner segments were linear with liner length as predicted by theory. The acoustic attenuation of the wall treatment was considerably greater than expected for available theory. This inordinate effectiveness of the wall treatment strongly suggests the possibility of using no-ring inlet suppressors when the required noise reduction is moderate. The decibel attenuations were higher than predicted above 2000 hertz, and the two suppressors behaved similarly despite the prediction of different behavior.

Dittmar, J. H.↗
NASA NTRS1976

Effects of long-chord acoustically treated stator vanes on fan noise. 2: Effect of acoustical treatment

A set of long chord stator vanes was designed to replace the vanes in an existing fan stage. The long chord stator vanes consisted of a turning section and axial extension pieces, all of which incorporated acoustic damping material. The long chord stator vanes were tested in two lengths, with the long version giving more noise reduction than the short, primarily because of the additional lining material. The noise reduction achieved with the acoustically treated long chord stator vanes was compared with the reduction achieved by an acoustically treated exhaust splitter. The long chord stator was at least as good as the splitter as a method for incorporating acoustic lining material. In addition, comparing an acoustic three ring inlet and an acoustic wall-only inlet discloses that the wall-only inlet could be used in an engine where the noise reduction requirements are not too stringent.

Dittmar, J. H.↗
NASA NTRS1976

A statistical method for treating molecular line opacities

A method for treating atomic and molecular line opacities in cool stellar atmospheres by a statistical opacity sampling is investigated. Under the usual assumptions of plane-parallel geometry, radiative equilibrium, hydrostatic equilibrium, and LTE, each radiative quantity is computed monochromatically at each chosen frequency and depth without any averaging of the opacity. The number of frequencies needed to allow an accurate integration of the energy flux over a given spectral interval is investigated as a function of depth, including opacity for both CN and C2. This method is extended to the calculation of a model atmosphere of a star, and the effect of the number and placement of frequency points is studied. The method is applied to treating molecular lines of CO, C2, and CN in a cool carbon star. Significant advantages of the opacity sampling method are its flexibility, which permits computation of models having arbitrary variations of chemical composition and of opacity with wavelength and depth, and generalizability to include departures from LTE.

Sneden, C.↗
NASA NTRS1981

Reissner's membrane and the spiral ligament in normal rats and those treated with ethacrynic acid

A description is presented of recent ultrastructural findings in Reissner's membrane and the spiral ligament in rats treated daily with ethacrynic acid during the 2nd and 3rd weeks of postnatal life, a period of final maturation of the inner ear and its fluids. A distension of Reissner's membrane in every cochlear turn, indicative of mild endolymphatic hydrops, was found to occur in animals that received a higher dose of ethacrynic acid. Ultrastructurally, the cytoplasm of the epithelial cells of Reissner's membrane showed increased electron density after treatment with ethacrynic acid. This increase was most pronounced in animals treated with a greater quantity of the drug. The epithelial cells had similar ultracellular features throughout except that the cells were much thinner in the region of maximal distension.

Ross, M. D.↗
NASA NTRS1989

Reduced reactivity to air on HF-treated YBa2Cu3O(7-x)surfaces

Treatment of YBa2Cu3O(7-x) films with a nonaqueous solution of HF in absolute ethanol results in the formation of an oxyfluoride with relative Y:Ba:Cu concentrations of 1:4:3 on the surface, as determined by X-ray photoelectron spectroscopy. The passivation properties of chemically treated films were tested by monitoring the growth of the high binding energy O 1s peak, associated with nonsuperconducting surface species, as a function of air exposure time, for both HF-treated and untreated films. The native oxyfluoride is shown to reduce the reactivity of the superconductor to air.

Vasquez, R. P.↗
NASA NTRS1988

Aquatic Plant/microbial Filters for Treating Septic Tank Effluent

The use of natural biological processes for treating many types of wastewater have been developed by NASA at the John C. Stennis Space Center, NSTL, Mississippi, during the past 15 years. The simplest form of this technology involves the use of aquatic plant/marsh filters for treatment of septic tank effluent. Septic tank effluent from single home units can be treated to advanced secondary levels and beyond by using a 37.2 sq m (400 sq ft) surface area washed gravel filter. This filter is generally 0.3 m (1 ft) deep with a surface cover of approximately 0.15 m (6 in.) of gravel. The plants in this filter are usually aesthetic or ornamental such as calla lily (Zantedeschia aethiopica), canna lily (Canna flaccida), elephant ear (Colocasia esculenta), and water iris (Iris pseudacorus).

Wolverton, B. C.↗