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Stability Constants Important to the Understanding of Plutonium in Environmental Waters, Hydroxy and Carbonate Complexation of Puo{Sub 2}{Sup +}

Description: The formation constants for the reactions PuO{sub 2}{sup +} + H{sub 2}O = PuO{sub 2}(OH) + H{sup +} and PuO{sub 2}{sup +} + CO{sub 3}{sup 2} = PuO{sub 2}(CO{sub 3}){sup {minus}} were determined in aqueous sodium perchlorate solutions by laser-induced photoacoustic spectroscopy. The molar absorptivity of the PuO{sub 2}{sup +} band at 569 nm decreased with increasing hydroxide concentration. Similarly, spectral changes occurred between 540 and 580 nm as the carbonate concentration was increased. … more
Date: April 20, 1990
Creator: Bennett, D. A.
Partner: UNT Libraries Government Documents Department
open access

Hot electron dynamics in graphene

Description: Graphene, a two-dimensional (2D) honeycomb structure allotrope of carbon atoms, has a long history since the invention of the pencil [Petroski (1989)] and the linear dispersion band structure proposed by Wallace [Wal]; however, only after Novoselov et al. successively isolated graphene from graphite [Novoselov et al. (2004)], it has been studied intensively during the recent years. It draws so much attentions not only because of its potential application in future electronic devices but also be… more
Date: October 20, 2011
Creator: Ling, Meng-Cheieh
Partner: UNT Libraries Government Documents Department
open access

First principles analysis of lattice dynamics for Fe-based superconductors and entropically-stabilized phases

Description: Modern calculations are becoming an essential, complementary tool to inelastic x-ray scattering studies, where x-rays are scattered inelastically to resolve meV phonons. Calculations of the inelastic structure factor for any value of Q assist in both planning the experiment and analyzing the results. Moreover, differences between the measured data and theoretical calculations help identify important new physics driving the properties of novel correlated systems. We have used such calculations t… more
Date: July 20, 2012
Creator: Hahn, Steven
Partner: UNT Libraries Government Documents Department
open access

Character and Effective Leadership of the Knowledge Worker

Description: Ulrich in the forward to the Zenger and Folkman (2002) book, ''The Extraordinary Leader'', wrote about the importance of character in leadership stating, ''Everything about great leaders radiates from character. Character improves the probability of exhibiting strong interpersonal skill. Some of this perceived character is innate . . . but more is driven by the leader's self-awareness and interactions with others'' (p. ix). The purpose of this study was to explore the relationship between leade… more
Date: April 20, 2005
Creator: Khoury, A E
Partner: UNT Libraries Government Documents Department
open access

Design and Evaluation of System Configurations for an EUV Mask Inspection Microscope

Description: This document is the third sub-report of the EUV AIM design study being conducted at LLNL on behalf of International Sematech (ISMT). The purpose of this study as identified in section 1.2 of the statement of work is to research the basic user requirements of an actinic defect characterization tool, potential design configurations and top-level specifications. The objectives of this design study specifically identified in section 1.3 of the statement of work were to: (1) Determine the user requ… more
Date: August 20, 2002
Creator: Barty, Anton; Taylor, John S.; Hudyma, Russell & Spiller, Eberhard
Partner: UNT Libraries Government Documents Department
open access

A Novel High Order Time Domain Vector Finite Element Method for the Simulation of Electromagnetic Devices

Description: The goal of this dissertation is twofold. The first part concerns the development of a numerical method for solving Maxwell's equations on unstructured hexahedral grids that employs both high order spatial and high order temporal discretizations. The second part involves the use of this method as a computational tool to perform high fidelity simulations of various electromagnetic devices such as optical transmission lines and photonic crystal structures to yield a level of accuracy that has pre… more
Date: July 20, 2004
Creator: Rieben, R N
Partner: UNT Libraries Government Documents Department
open access

STUDIES IN THE NUCLEAR CHEMISTRY OF PLUTONIUM, AMERICIUM, AND CURIUM AND MASSES OF THE HEAVIEST ELEMENTS

Description: Ion exchange column elution methods for the separation of americium and curium using tartrate and lactate solutions have been developed which are superior to citrate elutions. Tartrate elutions are suitable for slow separations and lactate elutions are satisfactory for general use where rapid separations are required. Fission and spallation products were isolated from Pu{sup 239} targets which had been bombarded with alpha particles of 21 to 37 Mev energy. Fission yield curves as well as fissio… more
Date: April 20, 1954
Creator: Glass, Richard Alois
Partner: UNT Libraries Government Documents Department
open access

A Study of Spectrophotometric Methods for the Determination of Osmium

Description: The development of rapid, selective, and sensitive methods for the determination of osmium in liquid samples is reported. The specific application of primary interest was the estimation of microgram or milligram quantities of osmium in homogeneous reactcr fuel solutions which contain uranyl sulfate as the major component and corrosion products of stainless steel as minor components. (W.L.H.)
Date: January 20, 1960
Creator: Goldstein, G.
Partner: UNT Libraries Government Documents Department
open access

Monitoring microbe-induced physical property changes using high-frequency acoustic waveform data: Toward the development of a microbial megascope

Description: A laboratory investigation was undertaken to determine the effect of microbe generated gas bubbles in controlled, saturated sediment columns utilizing a novel technique involving acoustic wave propagation. Specifically, the effect of denitrifying bacteria on saturated flow conditions was evaluated in light of the stimulated production of N{sub 2} gas and the resulting plugging of the pore throats. The propagation of high frequency acoustic waves through the sediment columns was used to locate t… more
Date: May 20, 2002
Creator: Williams, Kenneth Hurst
Partner: UNT Libraries Government Documents Department
open access

Enhanced mass removal due to phase explosion during high irradiance nanosecond laser ablation of silicon

Description: The morphology of craters resulting from high irradiance laser ablation of silicon was measured using a white light interferometry microscope. The craters show a dramatic increase in their depth and volume at a certain irradiance, indicating a change in the primary mechanism for mass removal. Laser shadowgraph imaging was used to characterize and differentiate the mass ejection processes for laser irradiances above and below the threshold value. Time-resolved images show distinct features of th… more
Date: May 20, 2000
Creator: Yoo, Jong Hyun
Partner: UNT Libraries Government Documents Department
open access

An Analysis Framework Addressing the Scale and Legibility of Large Scientific Data Sets

Description: Much of the previous work in the large data visualization area has solely focused on handling the scale of the data. This task is clearly a great challenge and necessary, but it is not sufficient. Applying standard visualization techniques to large scale data sets often creates complicated pictures where meaningful trends are lost. A second challenge, then, is to also provide algorithms that simplify what an analyst must understand, using either visual or quantitative means. This challenge can … more
Date: November 20, 2006
Creator: Childs, H. R.
Partner: UNT Libraries Government Documents Department
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Legacies of Power: The Cultural Heritage of Theological White Supremacy, A Case Study of Ku Klux Konfederatism in Denton County Texas, 1850-1930

Description: Undergraduate thesis exploring modern American racism as the result of the nation's legacy of theological white supremacy and its deep-rooted racial issues that remain unresolved because of the theo-mythologies embedded at the core of the nation's foundational fabric that have been and continue to be largely unaccounted for in corrective racial discourse through a case study of Denton, Texas. By employing localized interdisciplinary methodological approaches aimed at unveiling the theo-myth whi… more
Date: April 20, 2020
Creator: Luther Rummel, Jessica Rae
Partner: UNT Honors College
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