Gelling of cryogenic oxidizers Final report, 5 May 1965 - 4 Sep. 1966
Freeze dry methods for preparation of ultrafine, particle size lithium fluoride for cryogenic oxidizers
Beardell, A. J.↗
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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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Nitrosoazomethine derivatives
Oxidation and dehydrogenation of secondary amidoximes as method of preparing nitroso compounds
Boyer, J. H.↗
Polymeric Schiff bases. II.
Continuous azeotropic method for preparing high yields of azomethine monomers, including new polymeric Schiff bases, azines and ketanils
Crivello, J. V.↗
Trifunctional alcohol
New trifunctional alcohol derived from trimer acid and novel method of preparation
Hutchison, J. J.↗
Effect of the method of process on the control of microbial growth by water activity in foods
Two methods for preparation of intermediate moisture foods (IMF) were investigated; water absorption and water desorption technique. Results indicate that shelf stability of IMF systems might be enhanced by preparing foods by rehumidifying dehydrated foods to optimum water activity rather than drying food to reduce the water activity.
Labuzu, T. D.↗
Thermally stable polyimides from solutions of monomeric reactants
A method for preparing thermally stable resin-fiber-reinforced composites by using solutions of appropriate monomers is described. Solutions containing a dimethyl ester of an aryl tetracarboxylic acid, the monomethyl ester of nadic acid, and an aryl diamine were used to impregnate graphite fibers. Composites fabricated from these prepregs exhibited excellent thermo-oxidative stability and retention of mechanical properties at 315 C (600 F). These results compare favorably to those obtained from composites made from amide-acid prepolymers capped with reactive alicyclic rings. Monomeric solutions provide excellent shelf life and improved solubility compared to amide-acid prepolymer solutions.
Serafini, T. T.↗
High-friction mechanical grips
Plasma-arc spraying offers method of preparing required surface at greatly reduced cost. Coarse-grained, tungsten carbide bonded-nickel coating is applied by spraying. Coating has been used successfully on wedge-shaped mechanical test grips.
Stevens, E. G.↗
Part A: Hydrocarbon Suspension in Slush Hydrogen
Methods of preparing suspensions of a hydrocarbon in slush hydrogen for nuclear fuel element corrosion inhibition in rocket engines were investigated. Suspensions were prepared using approximately 5000 ppm by mass of methane, ethane, or cyclopropane in slush hydrogen. The suspensions were stable in the slush, but the hydrocarbons settled out of the liquid melt.
Sindt, C. F.↗
Processable high temperature resistant addition type polyimide laminating resins
Basic studies that were performed using model compounds to elucidate the polymerization mechanism of the so-called addition-type (A-type) polyimides are reviewed. The fabrication and properties of polyimide/graphite fiber composites using A-type polyimide prepolymers as the matrix are also reviewed. An alternate method for preparing processable A-type polyimides by means of in situ polymerization of monomer reactants (PMR) on the fiber reinforcement is described. The elevated temperature properties of A-type PMR/graphite fiber composites are also presented.
Serafini, T. T.↗
A review of processable high temperature resistant addition-type laminating resins
An important finding that resulted from research that was conducted to develop improved ablative resins was the discovery of a novel approach to synthesize processable high temperature resistant polymers. Low molecular weight polyimide prepolymers end-capped with norbornene groups were polymerized into thermo-oxidatively stable modified polyimides without the evolution of void producing volatile materials. This paper reviews basic studies that were performed using model compounds to elucidate the polymerization mechanism of the so-called addition-type polyimides. The fabrication and properties of polyimide/graphite fiber composites using A-type polyimide prepolymer as the matrix are described. An alternate method for preparing processable A-type polyimides by means of in situ polymerization of monomeric reactants on the fiber reinforcement is also described. Polyimide/graphite fiber composite performance at elevated temperatures is presented for A-type polyimides.
Serafini, T. T.↗
Long term flight electrodes
The reproducibility, stability, and methods of preparation for the various types and forms of biomedical electrodes are discussed. A critical and selective compilation of information on biological and/or physiological electrodes is presented. A discussion of plant hydrocolloids, clays, hydrophyllic colloids, synthetic waxes, and acrylic polymers is included.
Mosier, B.↗
Early detection of disease program: Evaluation of the cellular immune response
The early cellular responses of specific components of the leukocyte and epithelial cell populations to foreign challenges of both an infectious and noninfectious character were evaluated. Procedures for screening potential flight crews were developed, documented, and tested on a control population. Methods for preparing suitable populations of lymphocytes, polymorphonuclear leukocytes, macrophages, and epithelial cells were first established and evaluated. Epithelial cells from viral infected individuals were screened with a number of anti-viral antisera. This procedure showed the earliest indication of disease as well as providing a specific diagnosis to the physicians. Both macrophages and polymorphonuclear leukocytes were studied from normal individuals, smokers, and patients with viral infections. Newer techniques enabling better definition of lymphocyte subpopulations were then developed, namely the E and EAC rosette procedures for recognition of T (thymus-derived) and B (bone-marrow-derived) lymphocyte subpopulations. Lymphocyte and lymphocyte subpopulation response to multiple mitogens have been evaluated.
Criswell, B. S.↗
Thermionic work function of /Cs/ZnO
The collector electrode of a thermionic converter requires a material having a low thermionic work function and chemical stability in a Cs atmosphere in the 800-K range. This letter reports that ZnO with an adsorbed Cs film meets these requirements. The work function is approximately 1.3 eV. Various methods of preparing the ZnO film are described as well as an experiment in which Cs was replaced by K.
Sommer, A. H.↗
Several methods for concentrating bacteria in fluid samples
The sensitivities of the firefly luciferase - ATP flow system and luminol flow system were established as 300,000 E. coli per milliliter and 10,000 E. coli per milliliter respectively. To achieve the detection limit of 1,000 bacteria per milliliter previously established, a method of concentrating microorganisms using a sartorius membrane filter system is investigated. Catalase in 50% ethanol is found to be a stable luminol standard and can be used up to 24 hours with only a 10% loss of activity. The luminol reagent is also stable over a 24 hour period. A method of preparing relatively inexpensive luciferase from desiccated firefly tails is developed.
Thomas, R. R.↗
Fabrication of thin layer beta alumina
Beta alumina tubes having walls 700 microns, 300 microns, and 140 microns were processed by extrusion and sintering utilizing Ford proprietary binder and fabrication systems. Tubes prepared by this method have properties similar to tubes prepared by isostatic pressing and sintering, i.e. density greater than 98% of theoretical and a helium leak rate less than 3 x 10 to the -9th power cc/sq cm/sec. Ford ultrasonic bonding techniques were used for bonding beta alumina end caps to open ended beta -alumina tubes prior to sintering. After sintering, the bond was hermetic, and the integrity of the bonded area was comparable to the body of the tube.
Tennenhouse, G. J.↗
Flame retardant spandex type polyurethanes
Flame retardant elastomeric compositions were developed, comprised of: (1) spandex type polyurethane having incorporated into the polymer chain, halogen containing polyols; (2) conventional spandex type polyurethanes in physical admixture flame retardant additives; and (3) fluoroelastomeric resins in physical admixture with flame retardant additives. Methods of preparing fibers of the flame retardant elastomeric materials are presented and articles of manufacture comprised of the elastomeric materials are mentioned.
Howarth, J. T.↗
Whatever happened to silicon carbide
The progress made in silicon carbide semiconductor devices in the 1955 to 1975 time frame is examined and reasons are given for the present lack of interest in the material. Its physical and chemical properties and methods of preparation are discussed. Fabrication techniques and the characteristics of silicon carbide devices are reviewed. It is concluded that a combination of economic factors and the lack of progress in fabrication techniques leaves no viable market for SiC devices in the near future.
Campbell, R. B.↗
Method of making formulated plastic separators for soluble electrode cells
A method making a membrane comprised of a hydrochloric acid-insoluble sheet of a mixture of a rubber and a powdered ion transport material is disclosed. The sheet can be present as a coating upon a flexible and porous substrate. These membranes can be used in oxidation-reduction electrical accumulator cells wherein the reduction of one member of a couple is accompained by the oxidation of the other member of the couple on the other side of the cell and this must be accompained by a change in chloride ion concentration in both sides. The method comprises preparing a mixture of fine rubber particles, a solvent for the rubber and a powdered ion transport material. The mixture is formed into a sheet and dried to produce a microporous sheet. The ion transport material includes particles ranging from about 0.01 to 10 microns in size and comprises from 20 to 50 volume percent of the microporous sheet.
Sheibley, D. W.↗