Urea-ionorganic phosphate mixtures as prebiotic phosphorylating agents
Urea-inorganic phosphate mixtures as prebiotic nucleoside phosphorylating agents
Lohrmann, R.↗
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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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A comprehensive study of coupling agents in urethane and epoxy adhesives
Coupling agents in urethane and epoxy adhesives, discussing lap shear and T-peel tests on mild and stainless steels, Al and glass cloth substrates
Cassidy, P. E.↗
Optical bonding agents for severe environments
Test results and applications of elastors (General Electric RTV 665, Dow Corning (DC) XR-63-488, DC 93-500, DC 182, and DC 184) considered for use as optical bonding agents in aerospace environments are presented.
Pellicori, S. F.↗
Fluorine gas as a cleaning agent for Apollo bulk-sample containers
A technique has been developed for cleaning Apollo bulk sample containers using fluorine gas as the cleaning agent.
Liddle, R. H.↗
Feasibility study for the manufacture of zero gravity pharmaceuticles, immunological, and viral agents
The feasibility of extracting, isolating, purifying, separating, or preparing medical and biological products of high socio-economic value in space was studied. In particular, the study was designed to concentrate on the isolation or purification of virals, pharmaceutical and immunological agents by means of electrophoresis, as the Apollo 16 flight demonstrated that a mixed population of latex spheres (.2 and .8 microns) could be successfully separated by electrophoresis in space and without sedimentation with minimal convection. This prompted NASA scientists to look into the possibility of carrying out types of biochemical experiments that would utilize space for medical purposes.
Source record↗
Diamine curing agents for polyurethanes
Three aromatic diamines have properties that make them promising candidates as curing agents for converting isocyanates to polyurethanes with higher adhesive strengths, higher softening temperatures, better toughness, and improved abrasion resistance.
Bell, V. L.↗
Pathogenetic validation of the use of biological protective agents and early treatment in cases of radiation injury simulating radiation effects under space flight conditions
In considering a radiation safety system for space flights, the various measures to protect man against radiation include drug prophylaxis. At the present time a great deal of experimental material has been accumulated on the prevention and treatment of radiation injuries. Antiradiation effectiveness has been established for sulfur- and nitrogen-containing substances, auxins, cyanides, polynucleotides, mucopolysaccharides, lipopolysaccharides, aminosaccharides, synthetic polymers, vitamins, hormones, amino acids and other compounds which can be divided into two basic groups - biological and chemical protective agents.
Rogozkin, V. D.↗
Effects of multifunctional crosslinking agents on the thermomechanical properties of polyimide films
Three polyfunctional amines were synthesized. Polyimide films containing varying amounts of the amine crosslinking agents were prepared. Their thermomechanical properties were compared with those of control film samples prepared from difunctional amines. The effect of crosslink density on isothermal weight loss, polymer softening, and glass transition temperature is discussed.
Delvigs, P.↗
Development of spacecraft toxic gas removal agents
The development of agents suitable for removal of CO, NH3, NO2 SO2, and other spacecraft contaminants was approached. An extensive technology review was conducted, yielding a large number of potentially useful materials and/or concepts. Because the two toxic gases of greatest interest, CO and NH3, suggested the use of catalysis principles emphasis was placed on the intestigation of transition metals on various supports. Forty-three materials were prepared or obtained and 25 were tested. Gas chromatographic techniques were used to find seven candidates that effectively managed various combinations of the four toxic gases: none managed all. These candidates included six transition metal-containing preparations and a supported LiOH material. Three commercial charcoals showed some efficiency for the toxic gases and may constitute candidates for enhancement by doping with transition metals.
Moore, R. S.↗
Effects of tetraamine crosslinking agents on the thermomechanical properties of PMR polyimide composites
The effects were investigated of partial substitution of tetraamine crosslinking agents for diamine reactants on the thermomechanical properties of PMR polyimide resins and graphite fiber-reinforced composites. The effect of tetraamine content on isothermal weight loss, glass transition, and softening temperatures of neat resin samples is discussed. Composites were fabricated using PMR methodology. Monomeric solution of various stoichiometric ratios was used to impregnate Hercules HTS graphite fiber. The mechanical property retention characteristics of the composites at 316 C (600 F) are described.
Delvigs, P.↗
Debonding agent for silicone-rubber adhesive
Commercially-available blend of methylene chloride in saturated trichloro-trifluoroethane is utilized as chemical debonding agent for silicone rubber adhesive bonds, without damaging bonded material.
Holt, J. W.↗
Exploratory study on the effects of novel diamine curing agents and isocyanate precursors on the properties on new epoxy and urethane adhesives
Aromatic diamines based on diphenyl sulfone and benzophenone were studied as epoxy adhesive curing agents. Previously found differences in adhesive strengths for meta vs para orientation were not found in these series. The use of aluminum and alumina as fillers in a m,m prime-methylene dianiline-cured epoxy adhesive was not found to be beneficial to adhesive strength. Alumina filled adhesives had much lower strength than unfilled adhesives. The unfilled m,m prime-methylene dianiline-based epoxy adhesive had excellent resistance to moisture relative to a p,p prime-methylene dianiline-based adhesive and maintained good strengths up to 250 F. A glass fiber composite based on a m,m prime-methylene dianiline-cured epoxy appeared to be equivalent to the p,p prime-methylene dianiline-cured epoxy as judged by short beam shear tests.
Glasgow, D. G.↗
Bacillus cereus strain MCN as a debriding agent
Biologically active means are effective for rapidly removing scar tissue caused by burns or corrosive agents. Specially selected strain of bacteria applied to injury site releases enzymes which are active against eschar. These bacteria tend to locate between eschar and unburned tissue, thus providing optimal cell surface area arrangement for enzyme dispersal. Procedure may prove especially useful in treatment of disaster casualties under relatively primitive conditions.
Dalton, H. P.↗
The content of catecholamines in the adrenal glands and sections of the brain under hypokinesia and injection of some neurotropic agents
The dynamics of catecholamine content were studied in the adrenal glands and in various region of the brain of white rats under hypokinesia and injections of neurotropic agents. Profound changes in body catecholamine balance occured as a result of prolonged acute restriction of motor activity. Adrenalin retention increased and noradrenanalin retention decreased in the adrenal glands, hypothalamus, cerebral hemispheres, cerebellum and medulla oblongata. Observed alterations in catecholamine retention varied depending upon the type of neurotropic substance utilized. Mellipramine increased catecholamine retention in the tissues under observation while spasmolytin brought about an increase in adrenalin concentration in the adrenals and a decrease in the brain.
Melnik, B. E.↗
Pharmacological activity and toxicity of some neurotropic agents under conditions of experimental hypodynamia
The indices of pharmacological range, risk coefficients, ED50, LD50, the size of the area of toxic activity, and maximal tolerated and absolute lethal doses were compared in hypodynamic mice. The pharmacological activity of the test neurotropic agents exhibiting a central action underwent change, but their toxicity remained unchanged.
Kirichek, L. T.↗
Curing agent for polyepoxides and epoxy resins and composites cured therewith
A curing for a polyepoxide is described which contains a divalent aryl radical such as phenylene a tetravalent aryl radical such as a tetravalent benzene radical. An epoxide is cured by admixture with the curing agent. The cured epoxy product retains the usual properties of cured epoxides and, in addition, has a higher char residue after burning, on the order of 45% by weight. The higher char residue is of value in preventing release to the atmosphere of carbon fibers from carbon fiber-epoxy resin composites in the event of burning of the composite.
Serafini, T. T.↗
Binding agent for molding ceramic items
The invention refers to the fabrication of ceramic items by the molding method. It can be used to produce items of complicated configuration, in particular composition of binding agent for electroceramic items.
Beshentsev, B. D.↗
Formation of pyrophosphate on hydroxyapatite with thioesters as condensing agents
'Energy-rich' thioesters are shown to act as condensing agents in the formation of pyrophosphate on hydroxyapatite in the presence of water at ambient temperature. The yield of pyrophosphate based on thioester ranges from 2.5% to 11.4% and depends upon the pH and concentration of reactants. Reaction of 0.130 M hydroxyapatite suspended in a solution of 0.08 M sodium phosphate and 0.20 M imidazole hydrochloride (pH 7.0) with 0.10 M N,S-diacetylcysteamine for 6 days gives the highest yield of pyrophosphate (11.4%). Pyrophosphate formation requires the presence of hydroxyapatite, sodium phosphate and the thioester, N,S-diacetylcysteamine. The related thioester, N,S-diacetylcysteine, also yields pyrophosphate in reactions on hydroxyapatite.
Weber, A. L.↗