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Low Temperature Thermoluminescence of Gamma Irradiated Potassium Dihydrogen Phosphate

Description: Thermoluminescence in potassium dihydrogen phosphate (KDP) induced by Co/ sup 60/ gamma irradiation at liquid nitrogen temperature (-198 deg C) was investigated. Glow curves in the temperature range --196 to 0 deg C were measured for a series of gamma exposure dosages ranging from 10/sup 4/ roentgen to 5 x 10/sup 6/ roentgen. The heating rate used for glow curve measurements was 12 deg C per minute. Twice recrystallized Mallinckrodt reagent grade potassium dihydrogen phosphate, with a grain siz… more
Date: October 19, 1962
Creator: Sims, T. M.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries Government Documents Department
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Transient stress evolution and crystallization in laser-irradiated amorphous titania sol-gel films

Description: Amorphous TiO{sub 2} sol-gel films are irreversibly transformed to a crystalline anatase phase when heated to temperatures in excess of 575 K or subjected to intense pulsed or CW laser irradiation. The laser-induced transformation is initiated as a result of impurity absorption and subsequent heating, and results in densification and relative changes in compressive stress of the film. Isothermally annealed films exhibit a decrease in compressive stress as crystallization proceeds while an incre… more
Date: October 1, 1991
Creator: Exarhos, G.J.; Hess, N.J. (Pacific Northwest Lab., Richland, WA (United States)) & Wood, S. (Washington State Univ., Pullman, WA (United States). Dept. of Physics)
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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THE ORIGIN OF LIFE ON EARTH AND ELSEWHERE. II

Description: The synthesis of relatively complex organic molecules by ionizing and radical mechanisms (induced by high energy radiations, ultraviolet and electric discharge) from methane, ammonia, water, and hydrogen is described, both theoretically and experimentally. It is shown that the molecules which tend to be formed under such random conditions are the very ones which today are the common building blocks in the biological reconstruction of organic material. Such molecules are the amino acids, the sim… more
Date: October 19, 1960
Creator: Calvin, Melvin
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Applications of geothermal resources in the evaporation and crystallization industry. Final report, September 1976--October 1977

Description: The objective in this study was to determine the technical and economic feasibility of using low-temperature geothermal energy (hot brines) in place of steam from conventional sources in the evaporation and crystallization industry. A survey of major industries was carried out in order to choose three industries that were significant users of energy, could utilize geothermal brine, and demonstrate the broad range of industrial evaporation and crystallization operations. The selected industries … more
Date: October 1, 1977
Creator: May, S. C.; Basuino, D. J.; Doyle, P. T. & Rogers, A. N.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Atomic imaging and microanalysis of ceramics

Description: This paper is a short review of electron microscopy techniques, as applied to modern ceramics. Examples: representative of the significance of modern electron microscopy, methods of atomic resolution imaging, diffraction and spectroscopy in the task of characterising, and understanding typical ceramic materials are given. (JL)
Date: October 1, 1988
Creator: Thomas, G. & Ramesh, R.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Purification of mercury contaminated lithium hydroxide

Description: The object of this investigation was to determine an economical method of preparing pure lithium hydroxide from a mercury-contaminated lithium hydroxide monohydrate salt presently produced as a waste product. Pure lithium hydroxide has application for chemical removal of carbon dioxide from air and general open market sale if the mercury contamination is reduced to approximately one part per billion. Because of the uncertainty of the form of the mercury contaminant, different purification metho… more
Date: October 18, 1960
Creator: Bronfin, B. R.; Jenkins, D. M. & Wright, E. E. Jr.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Transient stress evolution and crystallization in laser-irradiated amorphous titania sol-gel films

Description: Amorphous TiO{sub 2} sol-gel films are irreversibly transformed to a crystalline anatase phase when heated to temperatures in excess of 575 K or subjected to intense pulsed or CW laser irradiation. The laser-induced transformation is initiated as a result of impurity absorption and subsequent heating, and results in densification and relative changes in compressive stress of the film. Isothermally annealed films exhibit a decrease in compressive stress as crystallization proceeds while an incre… more
Date: October 1, 1991
Creator: Exarhos, G. J.; Hess, N. J. & Wood, S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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COMPUTER MODELING OF HIGH-LEVEL WASTE GLASS TEMPERATURES WITHIN DWPF CANISTERS DURING POURING AND COOL DOWN

Description: This report describes the results of a computer simulation study to predict the temperature of the glass at any location inside a DWPF canister during pouring and subsequent cooling. These simulations are an integral part of a larger research focus aimed at developing methods to predict, evaluate, and ultimately suppress nepheline formation in HLW glasses. That larger research focus is centered on holistically understanding nepheline formation in HLW glass by exploring the fundamental thermal a… more
Date: October 9, 2011
Creator: Amoroso, J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Amorphous germanium as an electron or hole blocking contact on high-purity germanium detectors

Description: Experiments were performed in an attempt to make thin n/sup +/ contacts on high-purity germanium by the solid phase/sup 1)/ epitaxial regrowth of arsenic doped amorphous germanium. After cleaning the crystal surface with argon sputtering and trying many combinations of layers, it was not found possible to induce recrystallization below 400/sup 0/C. However, it was found that simple thermally evaporated amorphous Ge made fairly good electron or hole blocking contacts. Excellent spectrometers hav… more
Date: October 1, 1976
Creator: Hansen, William L. & Haller, Eugene E.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Atomic structure of nanometer-sized amorphous TiO2

Description: Amorphous titania (TiO{sub 2}) is an important precursor for synthesis of single-phase nanocrystalline anatase. We synthesized x-ray amorphous titania by hydrolysis of titanium ethoxide at the ice point. Transmission electron microscopy examination and nitrogen gas adsorption indicated the particle size of the synthesized titania is {approx} 2 nm. Synchrotron wide-angle x-ray scattering (WAXS) was used to probe the atomic correlations in this amorphous sample. Atomic pair-distribution function … more
Date: October 15, 2008
Creator: Zhang, H.; Chen, B.; Banfield, J. F. & Waychunas, G. A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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COMBINED RETENTION OF MOLYBDENUM AND SULFUR IN SIMULATED HIGH LEVEL WASTE GLASS

Description: This study was undertaken to investigate the effect of elevated sulfate and molybdenum concentrations in nuclear waste glasses. A matrix of 24 glasses was developed and the glasses were tested for acceptability based on visual observations, canister centerline-cooled heat treatments, and chemical composition analysis. Results from the chemical analysis of the rinse water from each sample were used to confirm the presence of SO{sup 2-}{sub 4} and MoO{sub 3} on the surface of glasses as well as o… more
Date: October 16, 2009
Creator: Fox, K.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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CRYSTALLIZATION IN MULTICOMPONENT GLASSES

Description: In glass processing situations involving glass crystallization, various crystalline forms nucleate, grow, and dissolve, typically in a nonuniform temperature field of molten glass subjected to convection. Nuclear waste glasses are remarkable examples of multicomponent vitrified mixtures involving partial crystallization. In the glass melter, crystals form and dissolve during batch-to-glass conversion, melter processing, and product cooling. Crystals often agglomerate and sink, and they may sett… more
Date: October 8, 2009
Creator: AA, KRUGER & PR, HRMA
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Quasicrystalline Approach to Predicting the Spinel-Nepheline Liquidus: Application to Nuclear Waste Glass Processing

Description: The crystal-melt equilibria in complex fifteen component melts are modeled based on quasicrystalline concepts. A pseudobinary phase diagram between acmite (which melts incongruently to a transition metal ferrite spinel) and nepheline is defined. The pseudobinary lies within the Al{sub 2}O{sub 3}-Fe{sub 2}O{sub 3}-Na{sub 2}O-SiO{sub 2} quaternary system that defines the crystallization of basalt glass melts. The pseudobinary provides the partitioning of species between the melt and the primary l… more
Date: October 10, 2005
Creator: Jantzen, Carol M. & Brown, Kevin G.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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FRACTIONAL CRYSTALLIZATION FLOWSHEET TESTS WITH ACTUAL TANK WASTE

Description: Laboratory-scale flowsheet tests of the fractional crystallization process were conducted with actual tank waste samples in a hot cell at the 222-S Laboratory. The process is designed to separate medium-curie liquid waste into a low-curie stream for feeding to supplemental treatment and a high-curie stream for double-shell tank storage. Separations criteria (for Cs-137 sulfate, and sodium) were exceeded in all three of the flowsheet tests that were performed.
Date: October 18, 2006
Creator: HERTING, D.L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Amorphous and nanocrystalline phase formation in highly-driven Al-based binary alloys

Description: Remarkable advances have been made since rapid solidification was first introduced to the field of materials science and technology. New types of materials such as amorphous alloys and nanostructure materials have been developed as a result of rapid solidification techniques. While these advances are, in many respects, ground breaking, much remains to be discerned concerning the fundamental relationships that exist between a liquid and a rapidly solidified solid. The scope of the current disser… more
Date: October 15, 2008
Creator: Kalay, Yunus Eren
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries Government Documents Department
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Basic Studies of the Separation of Uranium Hexafluoride from Mixtures Containing Chlorine Trifluoride and Hydrogen Fluoride

Description: Processes for the conversion of uranium compounds or uranium metal to uranium hexafluoride ordinarily involve the use of a powerful fluorinating agent. Elemental fluorine is used when the scale of operations justifies the construction of a fluorine generating plant, but for smaller operation the use of the interhalogens of fluorine has definite advantages. These compounds provide a high concentration of fluorinating power at moderate temperatures and pressures and are more easily stored and tra… more
Date: October 31, 1958
Creator: Bernhardt, H. A.; Barber, E. J.; Davis Jr., W. & McGill, R. M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Effect of secondary structure on the interactions of peptide T4 LYS (11-36) in mixtures of aqueous sodium chloride and 2,2,2,-Trifluoroethanol

Description: The potential of mean force for protein-protein interactions is key to the development of a statistical-mechanical model for salt-induced protein precipitation and crystallization, and for understanding certain disease states, including cataract formation and {beta}-amyloid pathology in Alzheimer's disease. Fluorescence anisotropy provides a method for quantitative characterization of intermolecular interactions due to reversible association. Monomer-dimer equilibria for the peptide T4 LYS(11-3… more
Date: October 1, 2001
Creator: Anderson, Camille O.; Spiegelberg, Susanne; Prausnitz, John M. & Blanch, Harvey W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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CO2 SELECTIVE CERAMIC MEMBRANE FOR WATER-GAS SHIFT REACTION WITH CONCOMITANT RECOVERY OF CO2

Description: This quarterly report focuses on the two specific topics: (1) Reversibility of CO{sub 2} affinity of hydrotalcite materials; and (2)In-situ crystallization of hydrotalcite on commercial tubular ceramic membrane as substrate. The former relates to the foundation of the use of the hydrotalcite material as a membrane. The later addresses the first step of the membrane synthesis we propose. Our study concludes that the CO{sub 2} affinity of the hydrotalcite material is reversible at 150 C and in th… more
Date: October 3, 2001
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Evaluation of the freeze-thaw/evaporation process for the treatment of produced waters. Quarterly technical progress report, July 1--September 30, 1995

Description: The use of freeze-crystallization is being increasingly acknowledged as a low-cost, energy-efficient method for purifying contaminated water. The natural freezing process can be coupled with natural evaporative processes to treat oil and gas produced waters year round in regions where sub-freezing temperatures seasonally occur. The objectives of this research are related to development of a commercially-economic natural freeze-thaw/evaporation (FTE) process for the treatment and purification of… more
Date: October 1, 1995
Creator: Boysen, J. & Morotti, J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Trifluoromethylmetallate anions as components of molecular charge transfer salts and superconductors.

Description: Whereas polymeric and common inorganic anions frequently deprive the synthetic chemist of a chance to modify a charge transfer salt's structure through anion alterations, discrete organometallic anions provide a vast opportunity to probe the structure/property correlations of a material through rational synthetic methods. We have recently undertaken a research effort aimed at the crystallization of conducting charge transfer salts which possess modifiable, organometallic anions as the charge co… more
Date: October 14, 1998
Creator: Schlueter, J. A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Flow patterns in sodium cold trap crystallizers

Description: From joint meeting of the American Nuclear Society and the Atomic Industrial Forum and Nuclear Energy Exhibition; San Francisco, California, USA (11 Nov 1973). A simple. inexpensive flow distribution device is required for sodium cold trap crystallizers. The use of inlet mixing nozzles to promote uniform crystallizer flow distribution was investigated. Usually, the inlet to the crystallizer is a straight pipe entering at one point of the annulus. The work compared the conventional inlet nozzle … more
Date: October 1, 1973
Creator: Lester, D. H. & Bloom, G. R.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Determination of ideal-gas enthalpies of formation for key compounds:

Description: The results of a study aimed at improvement of group-contribution methodology for estimation of thermodynamic properties of organic and organosilicon substances are reported. Specific weaknesses where particular group-contribution terms were unknown, or estimated because of lack of experimental data, are addressed by experimental studies of enthalpies of combustion in the condensed phase, vapor-pressure measurements, and differential scanning calorimetric (d.s.c.) heat-capacity measurements. Id… more
Date: October 1, 1991
Creator: Steele, W. V.; Chirico, R. D.; Nguyen, A.; Hossenlopp, I. A. & Smith, N. K.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

A phenomenological model for the effect of nanocrystalline microstructure on irradiation-induced amorphization in U{sub 3}Si

Description: A rate theory model is formulated wherein amorphous clusters are formed by a damage event. These clusters are considered centers of expansion (CEs), or excess-free-volume zones. Simultaneously, centers of compression (CCs) are created in the material. The CCs are local regions of increased density that travel through the material as an elastic (e.g., acoustic) shock wave. The CEs can be annihilated upon contact with a sufficient number of CCs, to form either a crystallized region indistinguisha… more
Date: October 1, 1994
Creator: Rest, J.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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