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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

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

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 role of catalyst precursor anions in coal gasification. Tenth quarterly report

Description: This project investigates the roles of various aqueous soluble catalyst precursors containing various anions, specifically acetate (CH{sub 3}COO{sup {minus}}), chloride (Cl{sup {minus}}), nitrate (NO{sub 3}{sup {minus}}), sulfate (SO{sub 4}{sup 2{minus}}) and carbonate (CO{sub 3}{sup 2{minus}}) on the surface electrical properties of coal and seeks to understand the effects of these salts on the adsorption, dispersion and activities of calcium and potassium. The current report discusses the reactivities the lignite derived char catalyzed by {approximately}0.05 - 0.07 %wt. potassium. The catalytic compounds used were potassium acetate, potassium carbonate, potassium chloride, potassium nitrate, and potassium sulfate. The initial concentration of each salt solution from which potassium was ion-exchanged onto the coal was 0.001 mol/L and the metal was ion-exchanged onto the coal at the approximate pHs of 2, 6 and 9. Although the potassium contents in the chars were similar ({approximately}0.05 - 0.07 %wt.), a wide spread of char reactivities were observed. Char gasification ranged from > 90 %wt. to < 20 %wt. At this time, no general correlation between char reactivities, catalyst type, catalyst precursor anions or catalyst loading pH is obvious. However, the data are currently being analyzed in terms of zeta potentials to determine the effect, if any, of the coal surface properties on catalyst dispersion and gasification rate.
Date: July 1, 1994
Creator: Abotsi, G. M. K.
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

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

MHD seed recovery/regeneration. Phase 2, Technical progress report, quarter ending May 1993

Description: The following tasks are reported: Design, refurbish, operation potassium formate (``backend``) system (Seed Regeneration Proof-of- Concept Facility); design, construct, operate calcium formate production POC (``frontend``) unit; project management and control; and Western seed studies.
Date: November 1, 1993
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

Gas Desorption and Electron Emission from 1 MeV Potassium Iion Bombardment of Stainless Steel

Description: Gas desorption and electron emission coefficients were measured for 1 MeV potassium ions incident on stainless steel at grazing angles (between 80 and 88 degrees from normal incidence) using a new gas-electron source diagnostic (GESD). Issues addressed in design and commissioning of the GESD include effects from backscattering of ions at the surface, space-charge limited emission current, and reproducibility of desorption measurements. We find that electron emission coefficients {gamma}{sub e} scale as 1/cos({theta}) up to angles of 86 degrees, where {gamma}{sub e} = 90. Nearer grazing incidence, {gamma}{sub e} is reduced below the 1/cos({theta}) scaling by nuclear scattering of ions through large angles, reaching {gamma}{sub e} = 135 at 88 degrees. Electrons were emitted with a measured temperature of {approx}30 eV. Gas desorption coefficients {gamma}{sub 0} were much larger, of order {gamma}{sub 0} = 10{sub 4}. They also varied with angle, but much more slowly than 1/cos({theta}). From this we conclude that the desorption was not entirely from adsorbed layers of gas on the surface. Two mitigation techniques were investigated: rough surfaces reduced electron emission by a factor of ten and gas desorption by a factor of two; a mild bake to {approx}220 degrees had no effect on electron emission, but decreased gas desorption by 15% near grazing incidence. We propose that gas desorption is due to electronic sputtering.
Date: March 25, 2004
Creator: Molvik, A; Covo, M K; Bieniosek, F; Prost, L; Seidl, P; Baca, D et al.
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&gt;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