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Absorption of purines, pyrimidines, and nucleoside in aqueous solution by montmorillionite occurring as cation exchange reaction
Gamma irradiation effect on dihydropyrimidines in aqueous solution and solid state, stressing conversion to unsaturated forms and ESR spectroscopy of free radicals
Electrochemistry for stress corrosion crack propagation through Ti alloy in aqueous solutions
Understanding of chemical properties of monovalent transition metal cations in aqueous solutions was obtained by a study of kinetics of reduction of different inorganic substrates by zinc, cadmium, and nickel.
Purines, pyrimidines and nucleosides absorption by Li-, Na-, Mg- and Ca-montmorillonite in aqueous solutions over range pH 2-12 by cation exchange
Electron injection into ZnO from aqueous solutions of stable substances, correlating injection with oxidation potential of substance
Amino acid stability in pyrolyzed Pleistocene Mercenaria shells, comparing decomposition rates for aqueous solution
Etching aluminum alloys with aqueous solution containing sulfuric acid, hydrofluoric acid, and an alkali metal dischromate for adhesive bonding
Addition of substances such as dimethylsulfoxide, glycerol, and gelatin to aqueous solutions of lactate dehydrogenase maintains enzymes in stable and fully active form when stored at 2 - 6 C.
Passed exhaled air through electrochemical cell containing alkali metal carbonate aqueous solution, and utilizes platinized electrodes causing reaction of oxygen at cathode with water in electrolyte, producing hydroxyl ions which react with carbon dioxide to form carbonate ions.
Application of radiation chemistry for deposition of metals by irradiation of aqueous solutions with high energy electrons is presented. Design of reaction vessel for irradiation of solution is illustrated. Features of radiochemical technique and procedures followed are described.
The Co-18Cr-20Ni-4 Vol % ThO2 powders were prepared by a flash drying selective reduction process starting with an aqueous solution of metal salts and colloidal thoria. Powders were consolidated and extruded into rods with a minimum density of 99% of theoretical. Swaging and annealing studies were conducted to determine the conditions that would lead to a product with high stress-rupture strength. The best process yielded a stress-rupture life of 7.2 hours at 10 KSI (69 MN sq m and 2000 F (1094 C). The alloy recrystallized to a duplex (coarse-fine) structure and thus did not exhibit the desired strength of 3000 hours at 15 KSI (103.5MN/sq m and 2000 F (1094 C).
A large reduction in drag coefficient has been observed in certain external flows of aqueous solutions with high molecular weight polymer additives. A change in the near wake configuration is phenomenologically responsible for the drag reduction, but the underlying mechanism is presently unknown. An analogy to known phenomena in particulate suspensions is drawn which suggests nonuniform concentration of the polymer additive as an explanation. An analysis of the boundary layer on a sphere with varying viscosity was made to investigate the effect. The results indicate early transition to turbulence for concentration variations whose length scale is small compared with the momentum boundary layer thickness. Stabilization and delayed transition are indicated for thicker concentration layers. Observations are suggested for the thin concentration layers.
Aqueous solutions of ammonium cyanide yield urea, cyanamide and guanidine when exposed to sunlight or an unfiltered 254 nm ultraviolet source. The prebiotic significance of these results is discussed.
In many biological research efforts, long chain organic molecules are studied by breaking large molecules into smaller components. Cleavage technique of recent interest is the use of solvated electrons. These are formed when aqueous solutions are bombarded with gamma radiation. Solvated electron is very reactive and can reduce most any species present, even to form free radicals.
Composition consists of dispersion of barium sulphate in aqueous solution of water-soluble inorganic binder. Binder is selected from group consisting of alkali metal sulphates. Coating exhibits high reflectance of ultraviolet light to wavelengths of approximately 200.0 nm, which compares favorably with high reflectance of virgin barium sulphate power.
Three personal hygiene cleansing agents and one laundry detergent (sodium dodecyl benzene sulfonate), which are all candidates for use on long-duration space missions, were evaluated in terms of dermatological effects on human subjects and effects on microbiological species. None of the four materials exhibited adverse dermatological effects from either skin patch tests of two weeks duration or a simulated Skylab personal hygiene regimen of up to four weeks duration. No significant alterations in skin microflora during the use regimen were found. None of the four materials were found to serve as microbiological support media for the species tested, but a species of air-borne mold was observed to grow rapidly in a neutralized aqueous solution. None of the candidate agents was found to be strongly biocidal.
Results are presented of a comprehensive search of the literature available, much of which has been generated by the research centers of NASA and its contractors, on plating and coating methods and techniques. Methods covered included: (1) electroplating from aqueous solutions; (2) electroplating from nonaqueous solutions; (3) electroplating from fused-salt baths; (4) electroforming; (5) electroless plating, immersion plating, and mirroring; (6) electroplating from gaseous plasmas; and (7) anodized films and conversion coatings.