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The Precipitation of Strontium Sulfate in Gels

Description: The growth of strontium sulfate precipitate by diffusion in various gels was studied by using optical transmission and confocal microscopies, scanning and transmission electron microscopies, and energy dispersive X ray fluorescence. Pure silica gel, pure agarose gel and the silica/agarose mixed gel at pH 7 - 10 were used throughout the present study. Precipitate morphology is sensitive to pH and to the nature of the growth medium. The morphology was observed as a function of time. The lack of c… more
Date: December 1991
Creator: Lee, Ya
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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PROBABILISTIC HAZARD ASSESSMENT FOR TORNADOES, STRAIGHT-LINE WIND, AND EXTREME PRECIPITATION AT THE SAVANNAH RIVER SITE

Description: Recent data sets for three meteorological phenomena with the potential to inflict damage on SRS facilities - tornadoes, straight winds, and heavy precipitation - are analyzed using appropriate statistical techniques to estimate occurrence probabilities for these events in the future. Summaries of the results for DOE-mandated return periods and comparisons to similar calculations performed in 1998 by Weber, et al., are given. Using tornado statistics for the states of Georgia and South Carolina,… more
Date: December 4, 2013
Creator: Werth, D.; Weber, A. & Shine, G.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Research on Reactor Waste Disposal: (Information Report)

Description: Report discussing research on the disposal of radioactive waste, specifically second-cycle waste and first-cycle neutralized waste. "In the absence of established environmental tolerances, the investigation reported herein have been directed for the most part in developing general methods of removing radioactivity from certain waste solutions to as low a value as practical."
Date: December 15, 1950
Creator: Lowe, C. S.; McEwen, M.; Mead, F. C., Jr. & Orban, Edward
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Performance of Evapotranspirative Covers Under Enhanced Precipitation: Preliminary Data

Description: Since January 2001, drainage lysimeter studies have been conducted at Yucca Flat, on the Nevada Test Site, in support of an evapotranspirative cover design. Yucca Flat has an arid climate with average precipitation of 16.5 cm annually. The facility consists of six drainage lysimeters 3 m in diameter, 2.4 m deep, and backfilled with a single layer of native soil. The bottom of each lysimeter is sealed and equipped with a small drain that enables direct measurement of saturated drainage. Each lys… more
Date: February 1, 2007
Creator: David C. Anderson, Lloyd T. Desotell, David B. Hudson, Gregory J. Shott, Vefa Yucel
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Upscaling of Bio-mediated Soil Improvement

Description: As demand for soil improvement continues to increase, new, sustainable, and innocuous methods are needed to alter the mechanical properties of soils. Recent research has demonstrated the potential of bio-mediated soil improvement for geotechnical applications (DeJong et al. 2006, Whiffin et al. 2007). Upscaling the bio-mediated treatment process for in situ implementation presents a number of challenges to be addressed, including soil and pore fluid interactions, bioaugmentation versus biostimu… more
Date: October 1, 2009
Creator: DeJong, J. T.; Martinez, B. C.; Mortensen, B. M.; Nelson, D. C.; Waller, J. T.; Weil, M. H. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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COAMPS Application to Dispersion Scavenging Problem: Heavy Precipitation Simulation

Description: Precipitation scavenging can effectively remove particulates from the atmosphere. Therefore, this process is of importance in the real-time modeling of atmospheric transport for hazardous materials. To account for the rainfall effect in LLNL operational dispersion model, a modified version of a standard below-cloud aerosol scavenging model has been developed to handle the emergency response in this scenario (Loosmore and Cerdewall, 2003, hereafter referred to as LC). Two types of rain data can … more
Date: May 5, 2004
Creator: Chin, H. & Cederwall, R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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A Constrained Stochastic Weather Generator for Daily Mean Air Temperature and Precipitation

Description: This article develops and tests a constrained stochastic weather generator (CSWG) for producing daily mean air temperature and precipitation based on annual mean air temperature and precipitation from tree-ring records. It presents a unique method that can be used to explore historic (e.g., archeological questions) or future (e.g., climate change) daily weather conditions based upon specified annual values.
Date: January 21, 2021
Creator: Pan, Feifei; Nagaoka, Lisa; Wolverton, Steven J.; Atkinson, Samuel F.; Kohler, Timothy A. & O'Neill, Marty
Item Type: Refine your search to only Article
Partner: University of North Texas
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Development of an Experimental Data Base and Theories for Prediction of Thermodynamic Properties of Aqueous Electrolytes and Nonelectrolytes of Geochemical Significance at Supercritical Temperatures and Pressures.

Description: The objective of this research was to combine new experimental measurements on heat capacities, volumes, and association constants of key compounds with theoretical equations of state and with first principles quantum mechanical calculations to generate predictions of thermodynamic data. The resulting thermodynamic data allow quantitative models of geochemical processes at high temperatures and pressures. Research funded by a DOE grant to Prof. Robert Wood at the University of Delaware involved… more
Date: October 11, 2005
Creator: Wood, Robert H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Final report for DOE Grant No. DE-FG02-07ER64404 - Field Investigations of Microbially Facilitated Calcite Precipitation for Immobilization of Strontium-90 and Other Trace Metals in the Subsurface

Description: Subsurface radionuclide and metal contaminants throughout the U.S. Department of Energy (DOE) complex pose one of DOE’s greatest challenges for long-term stewardship. One promising stabilization mechanism for divalent ions, such as the short-lived radionuclide 90Sr, is co-precipitation in calcite. We have previously found that that nutrient addition can stimulate microbial ureolytic activity that this activity accelerates calcite precipitation and co-precipitation of Sr, and that hig… more
Date: October 12, 2012
Creator: Smith, Robert W.; Fujita, Yoshiko; Ginn, Timothy R. & Hubbard, Susan S.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Zirconium-Precipitation Pilot Plant

Description: This report follows an investigation with the objectives to improve the design of an existing pilot plant to allow better control of operating variables than was attained by previous investigators, and to determine the effect of leaching time on phthalate recovery.
Date: September 30, 1950
Creator: Parish, G. T.; Bakal, R.; Goodman, E. I. & Larsen, H. A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Gamma Prime Precipitation Mechanisms and Solute Partitioning in Ni-base Alloys

Description: Nickel-base superalloys have been emerged as materials for gas turbines used for jet propulsion and electricity generation. The strength of the superalloys depends mainly from an ordered precipitates of L12 structure, so called gamma prime (γ’) dispersed within the disorder γ matrix. The Ni-base alloys investigated in this dissertation comprise both model alloy systems based on Ni-Al-Cr and Ni-Al-Co as well as the commercial alloy Rene N5. Classical nucleation and growth mechanism dominates the… more
Date: August 2014
Creator: Rojhirunsakool, Tanaporn
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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An Isochronal Differential Microcalorimeter

Description: An isochronal differential-type microcalorimeter has been designed and constructed. As a result of its simple design it is very easy to handle the samples and assemble the calorimeter. Important to the operation of the calorimeter is a program, also working on the differential principle, that provides linear temperature rise of the samples. This calorimeter is used to measure very small energy releases such as those found in precipitation, stored energy, etc. It is demonstrated that the calorim… more
Date: February 25, 1963
Creator: Arndt, R. A. & Fujita, F. E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Collaborative Research: MRA: Particulates in canopy flowpaths: A missing mass flux at the macrosystem scale?

Description: Data management plan for the grant, "Collaborative Research: MRA: Particulates in canopy flowpaths: A missing mass flux at the macrosystem scale?" This research will investigate a vital, but currently uncharacterized, macrosystem biogeochemical function within forest canopies at the very start of the terrestrial hydrologic cycle: particulate concentration, flux, and composition in rainwaters draining from forest canopies. We will address three major objectives: (1) Estimate the net rainfall (TF… more
Date: 2022-08-01/2027-07-31
Creator: Ponette-González, Alexandra G.
Item Type: Refine your search to only Text
Partner: UNT College of Liberal Arts & Social Sciences
open access

Developing Precipitation Hardenable High Entropy Alloys

Description: High entropy alloys (HEAs) is a concept wherein alloys are constructed with five or more elements mixed in equal proportions; these are also known as multi-principle elements (MPEs) or complex concentrated alloys (CCAs). This PhD thesis dissertation presents research conducted to develop precipitation-hardenable high entropy alloys using a much-studied fcc-based equi-atomic quaternary alloy (CoCrFeNi). Minor additions of aluminium make the alloy amenable for precipitating ordered intermetallic … more
Date: August 2017
Creator: Gwalani, Bharat
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Investigation of the Potential for 90Sr Immobilization in INTEC Perched Water via Microbially Facilitated Calcite Precipitation

Description: The goal of this work is to evaluate the applicability of a biogeochemical sequestration approach for remediation of 90Sr contamination in perched water zones underlying the Idaho Nuclear Technology and Engineering Center (INTEC). The approach is based on the accelerated co-precipitation of the contaminant in calcite, where the acceleration is catalyzed by the microbial urea hydrolysis. We have previously demonstrated the potential for this remediation mechanism to immobilize strontium. Urea hy… more
Date: October 1, 2006
Creator: Fujita, Yoshiko; Wright, Karen E. & Smith, William A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

MECHANISMS OF FRACTIONATION

Description: The mechanisms involved in fractionation as measured in samples obtained early from drone planes during the cloud rise or from manned aircraft a few hours later are discussed. A key problem in fractionation is the formation of the precipitate in the cloud, and an attcmpt is made to describe this mechanism. (W.D.M.)
Date: November 16, 1953
Creator: Magee, J.L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Precipitation-Runoff Modeling System: User's Manual

Description: From introduction: This documentation is designed to provide the user with the basic philosophy and structure of PRMS, instructions for application of established models designed as cataloged procedures, and instructions for interaction with the PRMS library to permit user additions or modifications of model components. The components and subroutines described in this document are those available at the time of publication. However, the library is dynamic and will be enhanced and updated throug… more
Date: 1983
Creator: Leavesley, G. H.; Lichty, R. W.; Troutman, B. M. & Saindon, L. G.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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