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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 595 records · Page 33
All sourcesNASA NTRSDOE OSTI
NASA NTRS1973

Integrated circuit package with lead structure and method of preparing the same

A beam-lead integrated circuit package assembly including a beam-lead integrated circuit chip, a lead frame array bonded to projecting fingers of the chip, a rubber potting compound disposed around the chip, and an encapsulating molded plastic is described. The lead frame array is prepared by photographically printing a lead pattern on a base metal sheet, selectively etching to remove metal between leads, and plating with gold. Joining of the chip to the lead frame array is carried out by thermocompression bonding of mating goldplated surfaces. A small amount of silicone rubber is then applied to cover the chip and bonded joints, and the package is encapsulated with epoxy resin, applied by molding.

Kennedy, B. W.↗
NASA NTRS1974

Reinforced polyquinoxaline gasket and method of preparing the same

A gasket or seal resistant to ionizing radiation and liquid hydrogen temperatures is made up of a laminated polyquinoxaline resin-fiberglass cloth body portion and a molded polyquinoxaline encapsulating film. The laminated body is prepared by stacking thin sheets of the resin alternately with fiberglass cloth and heating the assembly under pressure with the temperature, pressure and resin film thickness being controlled so that only partial impregnation of the fiberglass cloth is produced. The encapsulating resin film is preheated at about 300 f and applied to the laminate body by molding at a temperature of about 625 F. The molded gasket is then deflashed and post-cured by heating at 675 to 700 F.

Vanauken, R.↗
NASA NTRS1974

Intumescent composition, foamed product prepared therewith and process for making same

An intumescent composition and the foamed product prepared by heating the composition are provided. The composition comprises the reaction product of para-benzoquinone dioxime and a concentrated mineral acid such as sulfuric acid, phosphoric acid, and polyphosphoric acid. The composition is useful as an intumescent agent either by itself or when combined with other materials. A fire-resistant and heat-insulating composition is provided by heating the intumescent composition above its intumescent temperature.

Riccitiello, S. R.↗
NASA NTRS1974

Preparative electrophoresis of living lymphocytes

Vertical liquid columns containing low molecular weight dextran density gradients can be used for preparative lymphocyte electrophoresis on earth, in simulation of 0 gravity conditions. Another method that has been tested at 1 G, is the electrophoresis of lymphocytes in a upward direction in vertical columns. By both methods up to 10 to the 7th power lymphocytes can be separated at one time in a 30 cm glass column of 8 mm inside diameter, at 12 v/cm, in 2 hours. Due to convection and sedimentation problems, the separation at 1 G is less than ideal, but it is expected that at 0 gravity electrophoresis will prove to be a uniquely powerful cell separation tool. The technical feasibility of electrophoresing inert particles at 0 G has been proven earlier, during the flight of Apollo 16.

Vanoss, C. J.↗
NASA NTRS1974

Preparative liquid column electrophoresis of T and B lymphocytes at gravity = 1

Vertical liquid columns containing low-molecular-weight dextran density gradients can be used for preparative lymphocyte electrophoresis on earth, in simulation of zero gravity conditions. Another method that has been tested at 1 g, is the electrophoresis of lymphocytes in an upward direction in vertical columns. By both methods up to 100 million lymphocytes can be separated at one time in a 30-cm glass column of 8-mm inside diameter, at 12 V/cm, in two hours. Due to convection and sedimentation problems, the separation at 1 g is less than ideal, but it is expected that at zero gravity electrophoresis will probe to be a uniquely powerful cell separation tool.

Van Oss, C. J.↗
NASA NTRS1974

Irregular bilayer structure in vesicles prepared from Halobacterium cutirubrum lipids

Fluorescent probes were used to study the structure of the cell envelope of Halobacterium cutirubrum, and, in particular, to explore the effect of the heterogeneity of the lipids in this organism on the structure of the bilayers. The fluorescence polarization of perylene was followed in vesicles of unfractionated lipids and polar lipids as a function of temperature in 3.4 M solutions of NaCl, NaNO3, and KSCN, and it was found that vesicles of unfractionated lipids were more perturbed by chaotropic agents than polar lipids. The dependence of the relaxation times of perylene on temperature was studied in cell envelopes and in vesicles prepared from polar lipids, unfractionated lipids, and mixtures of polar and neutral lipids.

Lanyi, J. K.↗
NASA NTRS1974

Procedure for preparation for shipment of natural gas storage vessel

A method for preparing a natural gas storage vessel for shipment is presented. The gas is stored at 3,000 pounds per square inch. The safety precautions to be observed are emphasized. The equipment and process for purging the tank and sampling the exit gas flow are described. A diagram of the pressure vessel and the equipment is provided.

Amawd, A. M.↗
NASA NTRS1975

Preparation, testing, and delivery of low density polyimide foam panels

Plastic foams based on polyimide resins were shown to be stable at relatively high temperatures, and to possess very low flame spread and smoke generation characteristics. A system and process were developed to prepare low-density polyimide foam from a liquid formulation. The system is based on the reaction of micropulverized grade pyromellitic dianhydride with a polymeric diisocyanate. The panels produced were postcured at elevated temperatures to achieve maximum thermal and fire resistance, and incorporation of a fire retardant into the formulation was considered. The effects of a flame retardant (Flameout 5600B1) were investigated, but eliminated in preference to the postcuring approach.

Ball, G. L., III↗
NASA NTRS1975

A study of the oxide dispersion and recrystallization in NiCrAl prepared from preoxidized powder

The sintered aluminum powder (SAP) technique of dispersion strengthening (formation of an oxide dispersion by preoxidation of metal powders) was applied to atomized powder of a nickel alloy containing, by weight, 17% Cr, 5% Al, and 0.2% Y. The SAP-NiCrAl alloy (without the ytterbium removed by oxdation) was worked by extrusion and rod rolling at 1205 C and by swaging at 760 C. Annealing treatments were applied after working to determine the recrystallization response. The NiCrAlY alloy, similarly prepared from atomized powder, but without a preoxidation treatment, was examined for comparison. The SAP-NiCrAl alloy exhibited oxide particle size and spacing much larger than that usually observed in oxide dispersion strengthened alloys; nonetheless, it was possible to achieve abnormal (secondary) recrystallization in the SAP-NiCrAl alloy as has been reported for other oxide dispersion strengthened alloys. In contrast, the unoxidized NiCrAlY alloy exhibited only primary recrystallization.

Glasgow, T. K.↗
NASA NTRS1975

Prepared to launch

The verification of the interface between the preflight prepare-to-launch and flight program, targeting load, and flight program initialization was described. This is done using the digital command system coupled with a flight program patch and a memory dump command, the 6D/LVDC simulator, and a program trace through phase 1 initialization.

Source record↗
NASA NTRS1975

Autonomous navigation preparations for future unmanned space missions

In order to prepare for the era of autonomous navigation, this paper first examines existing techniques for spacecraft navigation by describing the basic elements of the Mark-I and II navigation technologies. The remainder of the paper deals with identification of criteria which necessitate onboard navigation, and with promising solutions now under consideration. An attractive solution possibility is proposed which utilizes narrow-angle optics, a charge-coupled device area-array image sensor, a small advanced onboard flight computer, and a simplified set of software algorithms. Onboard commands would be derived and sent to the appropriate spacecraft attitude control, propulsion, and science platform pointing subsystems. The proposed autonomous navigation system does not address all mission options, but focuses primarily on precision approach trajectory control and adaptive science instrument pointing for asteroid, cometary, and outer planet satellite missions.

Kohlhase, C. E.↗
NASA NTRS1975

Guidelines for the planning and preparation of illustrated technical talks

Guidelines are presented for the preparation of illustrated talks which are audience oriented and which are aimed at the efficient transfer of technical information. Early decisions concerning the required number of slides are helpful in initial planning for a good quality talk. Detailed considerations are: the establishment of limited objectives, selection of appropriate slide material, development of a text which is well coordinated with the slides, and accurate timing.

Hubbard, H. H.↗
NASA NTRS1975

A study of the oxide dispersion and recrystallization in NiCrAl prepared from preoxidized powder

The SAP technique of dispersion strengthening (formation of an oxide dispersion by preoxidation of metal powders) was applied to atomized powder of the alloy Ni-17Cr-5Al-0.2 Y. SAP-NiCrAl was worked by extrusion and rod rolling at 1205 C and by swaging at 760 C. A variety of annealing treatments were applied after working to determine the recrystallization response. NiCrAlY, similarly prepared from atomized powder, but without a preoxidation treatment, was examined for comparison. The SAP-NiCrAl of this study exhibited oxide particle size and spacing much larger than that usually observed in oxide dispersion strengthened alloys; nonetheless, it was possible to achieve abnormal (secondary) recrystallization in the SAP-NiCrAl as has been reported for other oxide dispersion strengthened alloys. In contrast, unoxidized NiCrAlY exhibited only primary recrystallization.

Glasgow, T. K.↗
NASA NTRS1975

Preparation of tantalum-based alloys by a unique CVD process

The paper describes a sequential pulsing technique for deposition of refractory alloys and evaluates the technique for the deposition of the tantalum-base alloys Ta-10W (Ta-10 st% W) and T-111 (Ta-8 wt% W-2 wt% Hf). The deposition cycle for Ta-10W was chosen as alternate injections of TaCl5 plus hydrogen and WCl6 plus hydrogen. The cycle for T-111 was chosen as injections of TaCl5 plus hydrogen interspersed with injections of WCl6 plus hydrogen. A temperature range of 900-1300 C was chosen for both alloys. The ability of the pulse process to blanket a uniformly heated section of substrate with a mixture of gases, whose composition varies not with position on the substrate but instead with time of residence in the reactor, allows metal of uniform thickness to be deposited. It is shown that Ta and W can be deposited at high temperature with the formation of a dense columnar grain structure, so that the feasibility of preparing uniformly thick deposits of these elements by a 'pulsing' modification of CVD is demonstrated. A similar attempt to deposit T-111 was unsuccessful due to the difficulty in reducing HfCl4.

Bryant, W. A.↗
NASA NTRS1976

STS payloads mission control study continuation phase A-1. Volume 2-C, task 3: Identification of joint activities and estimation of resources in preparation for joint flight operations

Payload mission control concepts are developed for real time flight operations of STS. Flight planning, training, simulations, and other flight preparations are included. Payload activities for the preflight phase, activity sequences and organizational allocations, and traffic and experience factors to establish composite man-loading for joint STS payload activities are identified for flight operations from 1980 to 1985.

Source record↗
NASA NTRS1977

Method of preparing zinc orthotitanate pigment

Zinc orthotitanate suitable for use as a pigment for spacecraft thermal control coatings is prepared by heating a slightly zinc deficient reaction mixture of precipitated oxalates of zinc and titanium. The reaction mixture can be formed by coprecipitation of zinc and titanium oxalates from chloride solution or by mixing separately precipitated oxalates. The mixture is first heated to 400 to 600 C to remove volatiles and is then rapidly heated at 900 to 1200 C. Zinc orthotitanate produced by this method exhibits the very fine particle size needed for thermal control coatings as well as stability in a space environment.

Gates, D. W.↗