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Preparation, Identification, and Crystal Structure of a Pentavalent Americium Compound, KAmO₂F₂

Description: From abstract: "A compound that is shown to be KAmO₂F₂ is prepared by the addition of a saturated solution of KF to an acid solution of pentavalent americium." The report further discusses the crystal structure, lattice parameters, number of molecules per unit cell, space group, and atomic positions for the compound.
Date: 1953
Creator: Asprey, L. B.; Ellinger, F. H. & Zachariasen, William H.
Partner: UNT Libraries Government Documents Department

Dissolution of NaK

Description: Abstract: "A rapid yet safe method for the dissolution of sodium-potassium alloys prior to chemical or instrumental analysis has been devised. The alloy is submerged beneath the surface of an inert organic reagent and dissolved at a controlled rate by adding methanol drop-by-drop. A blanket of inert gas is maintained over the reaction flask. The procedure has been successfully used to dissolve samples of NaK in the range of 0.05 to 25 grams."
Date: December 2, 1952
Creator: White, J. C.; Talbott, C. K. & Brady, L. J.
Partner: UNT Libraries Government Documents Department

Reactivity of Ozone with Solid Potassium Iodide Investigated by Atomic Force Microscopy

Description: The reaction of ozone with the (100) plane of solid potassium iodide (KI) was investigated using atomic force microscopy (AFM). The reaction forming potassium iodate (KIO{sub 3}) initiates at step edges prior to reacting on the flat terraces. Small domains of KIO{sub 3}, initially 3.8 {angstrom} in height are formed on the top of step edges. Following reaction at the step edge, domains of KIO{sub 3} are formed across the terraces. With prolonged exposure to ozone, KIO{sub 3} domains nucleate further growth until the surface is evenly covered with KIO{sub 3} particles that are 4-6 nm in height, at which point the surface is passivated and the reaction terminates.
Date: April 14, 2008
Creator: Mulleregan, Alice; Brown, Matthew A.; Ashby, Paul D.; Ogletree, D. Frank; Salmeron, Miquel & Hemminger, John C.
Partner: UNT Libraries Government Documents Department

The Crystal Structure of Potassium Metavanadate Monohydrate, KVO3·H2O

Description: Report discussing the investigation of potassium metavanadate monohydrate and its crystal structure. Information regarding experimental work done on potassium metavanadate monohydrate, determination/refinement of its structure, and description/discussion of its structure are included.
Date: February 1954
Creator: Christ, C. L.; Clark, Joan R. & Evans, H. T., Jr.
Partner: UNT Libraries Government Documents Department

The effect of pulse duration on laser-induced damage by 1053-nm light in potassium dihydrogen phosphate crystals

Description: Laser induced damage in potassium dihydrogen phosphate (KDP) has previously been shown to depend significantly on pulse duration for 351-nm Gaussian pulses. In this work we studied the properties of damage initiated by 1053-nm temporally Gaussian pulses with 10ns and 3ns FWHM durations. Our results indicate that the number of damage sites induced by 1053-nm light scales with pulse duration ({tau}) as ({tau}{sub 1}/{tau}{sub 2}){sup 0.17} in contrast to the previously reported results for 351-nm light as ({tau}{sub 1}/{tau}{sub 2}){sup 0.35}. This indicates that damage site formation is significantly less probable at longer wavelengths for a given fluence.
Date: November 27, 2006
Creator: Cross, D A; Braunstein, M R & Carr, C W
Partner: UNT Libraries Government Documents Department

Effects of X-irradiation on Potassium Flux in Isolated Nerves

Description: The purpose of this study, therefore, was threefold in nature: (1) to determine the effects of x-irradiation on the influx and efflux of potassium in compound nerve fibers (2) to attempt to relate the radiation-induced changes in electrical activity with potassium flux and (3) to use the information obtained to gain insight into the possible cellular site (s) of radiation insult to compound nerves.
Date: August 1966
Creator: Ramsey, Christian Norman
Partner: UNT Libraries

Failure Test of a Double Chambered NaK-Filled Irradiation Capsule

Description: Report describing tests "in which a double chambered irradiation capsule containing NaK (sodium-potassium alloy) in its inner chamber was deliberately perforated to allow NaK (the heat transfer medium) and water to react within the capsule chambers" (p. 2). The report includes descriptions of the materials used in the tests, test procedures, and results.
Date: September 1961
Creator: Kosut, B. S.; Leggett, R. D. & Marshall, R. K.
Partner: UNT Libraries Government Documents Department

Scintillation Spectrometer 2: Simultaneous Measurement of Uranium, Thorium and Potassium in Common Rocks

Description: From abstract: "A method is described for the simultaneous radioassay of the uranium and thorium series and potassium in common rocks, or materials of comparable activity, in which the series are in secular equilibrium. The method is based on the measurement of the counting rate in three bands of the photon energy spectrum derived from the gamma-ray excitation of a scintillation crystal."
Date: June 1955
Creator: Hurley, Patrick M.
Partner: UNT Libraries Government Documents Department

CO2 Capture by Absorption With Potassium Carbonate

Description: The objective of this work is to improve the process for CO{sub 2} capture by alkanolamine absorption/stripping by developing an alternative solvent, aqueous K{sub 2}CO{sub 3} promoted by piperazine. Progress has been made in this reporting period on three subtasks. The rigorous Electrolyte Non-Random Two-Liquid (electrolyte-NRTL) model has been regressed to represent CO{sub 2} solubility in potassium carbonate/bicarbonate solutions. An analytical method for piperazine has been developed using a gas chromatograph. Funding has been obtained and equipment has been donated to provide for modifications of the existing pilot plant system with stainless steel materials.
Date: January 1, 2003
Creator: Rochelle, Gary T.; Seibert, A. Frank; Cullinane, J. Tim & Jones, Terraun
Partner: UNT Libraries Government Documents Department

Laboratory Experiments Bearing on the Origin and Evolution of Olivine-rich Chondrules

Description: Evaporation rates of K2O, Na2O, and FeO from chondrule-like liquids and the associated potassium isotopic fractionation of the evaporation residues were measured to help understand the processes and conditions that affected the chemical and isotopic compositions of olivine-rich Type IA and Type IIA chondrules from Semarkona. Both types of chondrules show evidence of having been significantly or totally molten. However, these chondrules do not have large or systematic potassium isotopic fractionation of the sort found in the laboratory evaporation experiments. The experimental results reported here provide new data regarding the evaporation kinetics of sodium and potassium from a chondrule-like melt and the potassium isotopic fractionation of evaporation residues run under various conditions ranging from high vacuum to pressures of one bar of H2+CO2, or H2, or helium. The lack of systematic isotopic fractionation of potassium in the Type IIA and Type IA chondrules compared with what is found in the vacuum and one-bar evaporation residues is interpreted as indicating that they evolved in a partially closed system where the residence time of the surrounding gas was sufficiently long for it to have become saturated in the evaporating species and for isotopic equilibration between the gas and the melt. A diffusion couple experiment juxtaposing chondrule-like melts with different potassium concentrations showed that the diffusivity of potassium is sufficiently fast at liquidus temperatures (DK>2-10-4cm2/s at 1650-C) that diffusion-limited evaporation cannot explain why, despite their having been molten, the Type IIA and Type IA chondrules show no systematic potassium isotopic fractionation.
Date: June 24, 2011
Creator: Richter, Frank M.; Mendybaev, Ruslan A.; Christensen, John N.; Ebel, Denton & Gaffney, Amy
Partner: UNT Libraries Government Documents Department

The role of catalyst precursor anions in coal gasification. Eighth quarterly report, [July--September 1993]

Description: This project investigates the roles of various aqueous soluble catalyst precursor anions, specifically acetate, chloride, nitrate, sulfate, and carbonate anions on the surface electrical properties of coal and seeks to understand the effects of these anions on the adsorption, dispersion and activities of calcium and potassium. The effects of the various anions on coal char gasification is currently under investigation. The influence of acetate, chloride and nitrate ions, when using the corresponding potassium compounds, are discussed in this report. The thermograms for the char preparation in nitrogen show that rapid devolatilization of moisture and other volatile materials occurs in the first 30 min. The rate of weight loss decreases significantly thereafter up to about 70 min. when char preparation was complete. Introduction of carbon dioxide after this time resulted in only a small amount of carbon gasification of the unloaded, demineralized coal. However, the chars containing the acetate, chloride or nitrate of potassium gave reactivities of 24.8, 30.4 or 24.3 %wt., respectively. The catalysts were ion-exchanged with the salt solutions and the corresponding potassium content were 2.9, 2.6 and 2.3 %wt. The higher reactivities of the catalyzed chars compared to the unloaded char correlates the high degree of demineralization and the resultant low catalytic activity by the inherent inorganic materials. It is observed that the potassium acetate and the potassium nitrate have similar reactivities, while the reactivity in the presence of KCl is higher. This finding contrasts some of the previous literature reports which show that oxygen-containing catalytic salts are more active catalysts due to the formation of carbon-oxygen-metal bonds which have been postulated as pre-requisites to carbon gasification.
Date: December 31, 1993
Creator: Abotsi, G. M. K.
Partner: UNT Libraries Government Documents Department

Radiation Doses to Hanford Workers from Natural Potassium-40

Description: The chemical element potassium is an essential mineral in people and is subject to homeostatic regulation. Natural potassium comprises three isotopes, 39K, 40K, and 41K. Potassium-40 is radioactive, with a half life of 1.248 billion years. In most transitions, it emits a β particle with a maximum energy of 0.560 MeV, and sometimes a gamma photon of 1.461 MeV. Because it is ubiquitous, 40K produces radiation dose to all human beings. This report contains the results of new measurements of 40K in 248 adult females and 2,037 adult males performed at the Department of Energy Hanford Site in 2006 and 2007. Potassium concentrations diminish with age, are generally lower in women than in men, and decrease with body mass index (BMI). The average annual effective dose from 40K in the body is 0.149 mSv y−1 for men and 0.123 mSv y−1 women respectively. Averaged over both men and women, the average effective dose per year is 0.136 mSv y−1. Calculated effective doses range from 0.069 to 0.243 mSv y−1 for adult males, and 0.067 to 0.203 mSv y−1 for adult females, a roughly three-fold variation for each gender. The need for dosimetric phantoms with a greater variety of BMI values should be investigated. From our data, it cannot be determined whether the potassium concentration in muscle in people with large BMI values differs from that in people with small BMI values. Similarly, it would be important to know the potassium concentration in other soft tissues, since much of the radiation dose is due to beta radiation, in which the source and target tissues are the same. These uncertainties should be evaluated to determine their consequences for dosimetry.
Date: February 13, 2009
Creator: Strom, Daniel J.; Lynch, Timothy P. & Weier, Dennis R.
Partner: UNT Libraries Government Documents Department