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Determination of nitrogen in boron carbide with the Leco UO-14 Nitrogen Determinator

Description: Use of various metals as fluxes for releasing nitrogen from boron carbide in the Leco Nitrogen Determinator was investigated. Metals such as iron, chromium, and molybdenum that wet the graphite crucible all promoted nitrogen release. Tin, copper, aluminum, and platinum did not wet the graphite and were of no value as fluxes. A procedure for sample handling and the resulting performance of the method are described. The precision at 0.06 to 0.6 percent nitrogen averaged 4 percent relative standard deviation.
Date: November 1, 1977
Creator: Gardner, R.D.; Ashley, W.H. & Henicksman, A.L.
Partner: UNT Libraries Government Documents Department


Description: Chlorine may be determined in polyurethane by gravimetric or spectrophotometric techniques. The sample is burned in a special combustion tube with two oxygen inlets, the products of combustion are absorbed in a solution containing sodium hydroxide and hydrogen peroxide, and the chlorine is measured either gravimetrically as silver chloride or spectrophotometrically using mercuric thiocyanate and ferric perchlorate. Eighteen determinations of cblorine in known solutions of sodium chloroacetate or perchloric acid gave an average recovery of 98.3% with a standard deviation of 2.8%. (auth)
Date: October 1, 1959
Creator: Henicksman, A.L.; VanKooten, E.H.; Gardner, R.D. & Ashley, W.H.
Partner: UNT Libraries Government Documents Department


Description: Tungsten in uranium--tungsten alloys is determined by precipitating the tungsten from a cold sulfuric acid solution using alpha -benzoinoxime and cinchonine as the precipitating agents. The precipitate is dgnited at 800 deg C and weighed as WO/sub 3/. Results of 94 determinations on known samples containing 20 to 40 milligrams of tungsten in the presence of 1 to 8 grams of uranium showed an average recovery of 100.1% with a standard deviation of 0.7%. (auth)
Date: September 1, 1958
Creator: Carpenter, R.L.; Gardner, R.D.; Ashley, W.H. & Henicksman, A.L.
Partner: UNT Libraries Government Documents Department

Fluorometric determination of uranium in natural waters

Description: Duplicate 200-..mu..l aliquots of the water samples, as received, are transferred by means of Eppendorf pipettors onto 0.4-g pellets of 2 percent LiF-98 percent NaF flux, contained in platinum dishes. The pellets are dried under heat lamps; then fused over special propane burners. The fused pellets are transferred to a Galvanek-Morrison fluorometer, where they are excited with ultraviolet radiation and the fluorescence is measured. The uranium is calculated by comparing the measured fluorescence with that of other pellets, carried through the same procedure, which contain aliquots of standard uranium solutions. The sensitivity of the method is about 0.2 ppB of uranium, and the precision is approximately 15 relative percent in the 0.2- to 10-ppB uranium concentration range.
Date: March 1, 1977
Creator: Hues, A. D.; Henicksman, A. L.; Ashley, W. H. & Romero, D.
Partner: UNT Libraries Government Documents Department