[Chemistry]

[Chemistry]

Date: unknown
Creator: unknown
Description: Photograph of two student mixing chemicals in a chemistry class. The male student is pouring liquid from a graduated cylinder into a round bottom flask, while the female student is using a pipette to pour liquid into a bottle. They are surrounded by chemistry lab material and are wearing protective aprons.
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CLOUD CHEMISTRY.

CLOUD CHEMISTRY.

Date: March 2001
Creator: Schwartz, S. E.
Description: Clouds present substantial concentrations of liquid-phase water, which can potentially serve as a medium for dissolution and reaction of atmospheric gases. The important precursors of acid deposition, SO{sub 2} and nitrogen oxides NO and NO{sub 2} are only sparingly soluble in clouds without further oxidation to sulfuric and nitric acids. In the case of SO{sub 2} aqueous-phase reaction with hydrogen peroxide, and to lesser extent ozone, are identified as important processes leading to this oxidation, and methods have been described by which to evaluate the rates of these reactions. The limited solubility of the nitrogen oxides precludes significant aqueous-phase reaction of these species, but gas-phase reactions in clouds can be important especially at night.
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PEROXYNITRITE CHEMISTRY

PEROXYNITRITE CHEMISTRY

Date: November 29, 2000
Creator: Lymar, S. V.
Description: This century old area of research has been experiencing a renaissance during the last decade, with the annual number of publications on the subject increasing from only one in 1990 to nearly 200 in the late-1990s. This renewed interest is stimulated by the discovery of biological roles of nitric oxide, distinguished by the 1998 Nobel prize, and the recognition that the conversion of nitric oxide into peroxynitrite may play major roles in human diseases associated with oxidative stress and in cellular defense against invading pathogens. Peroxynitrite (ONOO{sup {minus}})is a structural isomer of nitrate (NO{sub 3}{sup {minus}}) that contains a peroxo bond. The physiological route to ONOO{sup {minus}} is provided by the combination of nitric oxide ({center_dot}NO) with superoxide ({center_dot}O{sub 2}{sup {minus}}), an extremely rapid reaction occurring upon every encounter of these radicals (the upper dot denotes radical species). Both {center_dot}NO and {center_dot}O{sub 2}{sup {minus}} are the oxygen metabolic products simultaneously generated in a number of cell types within a human body. Compared to its precursors, peroxynitrite is a much stronger oxidant capable of oxidizing proteins, nucleic acids, and lipids.
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Technetium chemistry

Technetium chemistry

Date: April 1996
Creator: Burns, C.; Bryan, J.; Cotton, F.; Ott, K.; Kubas, G.; Haefner, S. et al.
Description: Technetium chemistry is a young and developing field. Despite the limited knowledge of its chemistry, technetium is the workhorse for nuclear medicine. Technetium is also a significant environmental concern because it is formed as a byproduct of nuclear weapons production and fission-power generators. Development of new technetium radio-pharmaceuticals and effective environmental control depends strongly upon knowledge of basic technetium chemistry. The authors performed research into the basic coordination and organometallic chemistry of technetium and used this knowledge to address nuclear medicine and environmental applications. This is the final report of a three-year Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL).
Contributing Partner: UNT Libraries Government Documents Department
CLUSTER CHEMISTRY

CLUSTER CHEMISTRY

Date: May 1, 1980
Creator: Muetterties, Earl L.
Description: Metal cluster chemistry is one of the most rapidly developing areas of inorganic and organometallic chemistry. Prior to 1960 only a few metal clusters were well characterized. However, shortly after the early development of boron cluster chemistry, the field of metal cluster chemistry began to grow at a very rapid rate and a structural and a qualitative theoretical understanding of clusters came quickly. Analyzed here is the chemistry and the general significance of clusters with particular emphasis on the cluster research within my group. The importance of coordinately unsaturated, very reactive metal clusters is the major subject of discussion.
Contributing Partner: UNT Libraries Government Documents Department
Metals in Chemistry and Biology: Computational Chemistry Studies

Metals in Chemistry and Biology: Computational Chemistry Studies

Date: May 2007
Creator: Dinescu, Adriana
Description: Numerous enzymatic reactions are controlled by the chemistry of metallic ions. This dissertation investigates the electronic properties of three transition metal (copper, chromium, and nickel) complexes and describes modeling studies performed on glutathione synthetase. (1) Copper nitrene complexes were computationally characterized, as these complexes have yet to be experimentally isolated. (2) Multireference calculations were carried out on a symmetric C2v chromium dimer derived from the crystal structure of the [(tBu3SiO)Cr(µ-OSitBu3)]2 complex. (3) The T-shaped geometry of a three-coordinate β-diketiminate nickel(I) complex with a CO ligand was compared and contrasted with isoelectronic and isosteric copper(II) complexes. (4) Glutathione synthetase (GS), an enzyme that belongs to the ATP-grasp superfamily, catalyzes the (Mg, ATP)-dependent biosynthesis of glutathione (GSH) from γ-glutamylcysteine and glycine. The free and reactant forms of human GS (wild-type and glycine mutants) were modeled computationally by employing molecular dynamics simulations, as these currently have not been structurally characterized.
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Demineralization of Saline Water by Electrically-Induced Adsorption on Porous Carbon Electrodes

Demineralization of Saline Water by Electrically-Induced Adsorption on Porous Carbon Electrodes

Date: March 1962
Creator: University of Oklahoma. Department of Chemistry
Description: Report containing information regarding the demineralization of water via carbon electrodes. Includes steps taken in the experiment, advancements made in the types of carbon material used, and cost estimates.
Contributing Partner: UNT Libraries Government Documents Department
[Chemistry Society, 1942]

[Chemistry Society, 1942]

Date: 1942
Creator: unknown
Description: Photograph of the chemistry society posing in front of the entrance of a building in the 1940's.
Contributing Partner: UNT Libraries Special Collections
[Chemistry Students in Lab]

[Chemistry Students in Lab]

Date: unknown
Creator: unknown
Description: Photograph of two male students studying chemicals in a laboratory. One student is sitting on a stool holding a test tube as the other student stands and watches.
Contributing Partner: UNT Libraries Special Collections
[Chemistry lab / robotics / forensics]

[Chemistry lab / robotics / forensics]

Date: January 22, 1994
Creator: Center for Media Production
Description: Video footage of students and faculty at the University of North Texas working in biology, robotics, and forensics labs.
Contributing Partner: UNT Libraries Special Collections
Isomerization Reactions in Organosilicon Chemistry

Isomerization Reactions in Organosilicon Chemistry

Date: August 1985
Creator: Kwak, Young-Woo
Description: None
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Models of Geothermal Brine Chemistry

Models of Geothermal Brine Chemistry

Date: March 29, 2002
Creator: Weare, Nancy Moller & Weare, John H.
Description: Many significant expenses encountered by the geothermal energy industry are related to chemical effects. When the composition, temperature of pressure of the fluids in the geological formation are changed, during reservoir evolution, well production, energy extraction or injection processes, the fluids that were originally at equilibrium with the formation minerals come to a new equilibrium composition, temperature and pressure. As a result, solid material can be precipitated, dissolved gases released and/or heat lost. Most geothermal energy operations experience these phenomena. For some resources, they create only minor problems. For others, they can have serious results, such as major scaling or corrosion of wells and plant equipment, reservoir permeability losses and toxic gas emission, that can significantly increase the costs of energy production and sometimes lead to site abandonment. In future operations that exploit deep heat sources and low permeability reservoirs, new chemical problems involving very high T, P rock/water interactions and unknown injection effects will arise.
Contributing Partner: UNT Libraries Government Documents Department
THE ADVANCED CHEMISTRY BASINS PROJECT

THE ADVANCED CHEMISTRY BASINS PROJECT

Date: April 5, 2004
Creator: Goddard, William; Meulbroek, Peter; Tang, Yongchun & III, Lawrence Cathles
Description: In the next decades, oil exploration by majors and independents will increasingly be in remote, inaccessible areas, or in areas where there has been extensive shallow exploration but deeper exploration potential may remain; areas where the collection of data is expensive, difficult, or even impossible, and where the most efficient use of existing data can drive the economics of the target. The ability to read hydrocarbon chemistry in terms of subsurface migration processes by relating it to the evolution of the basin and fluid migration is perhaps the single technological capability that could most improve our ability to explore effectively because it would allow us to use a vast store of existing or easily collected chemical data to determine the major migration pathways in a basin and to determine if there is deep exploration potential. To this end a the DOE funded a joint effort between California Institute of Technology, Cornell University, and GeoGroup Inc. to assemble a representative set of maturity and maturation kinetic models and develop an advanced basin model able to predict the chemistry of hydrocarbons in a basin from this input data. The four year project is now completed and has produced set of public domain ...
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Spin probes of chemistry in zeolites

Spin probes of chemistry in zeolites

Date: September 1, 1997
Creator: Werst, D.W. & Trifunac, A.D.
Description: Electron spin resonance (EPR) studies in zeolites are reviewed in which radiolysis was used to ionize the zeolite lattice, create reactive intermediates, spin label reaction products and to provide a window onto chemistry and transport of adsorbates and matrix control of chemistry. The review examines reactions of radical cations and the influence of the geometry constraints inside the zeolite, explores how zeolite model systems can be used to learn about energy and charge transfer in solids and illustrates the use of radiolysis and EPR for in situ spectroscopic studies of solid-acid catalysis. The various spin probes created inside the zeolite pores report on properties of the zeolites as well as shed light on radiolytic processes.
Contributing Partner: UNT Libraries Government Documents Department
General chemistry progress report

General chemistry progress report

Date: August 1, 1948
Creator: Barth, S.; Ford, M. & Dismore, P.
Description: This document is a de-classified August 1948 General Chemistry progress report from Monsanto Chemical`s Mound facility. General chemical properties of Postum compounds are discussed, and experimental data on these properties are presented.
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General chemistry progress report

General chemistry progress report

Date: July 1, 1948
Creator: Barth, S.; Ford, M. & Dismore, P.
Description: This document is a de-classified July 1948 General Chemistry Progress Report from Monsanto Chemical`s Mound facility. Detailed discussions of numerous studies of Postum compounds are included in this report, and experimental data on various chemical and physical properties of these compounds are given.
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General chemistry progress report

General chemistry progress report

Date: June 1, 1948
Creator: Barth, S.; Ford, M. & Dismore, P.
Description: Decomposition potentials of bismuth solutions of 1.037 and 0.509 grams of the metal per 100 ml. of 1.5 nitric acid were found to be -0.06 and -0.09 volts to N.C.E. These results confirm previous values and indicate that bismuth will not be reduced from production solutions at the potential of the normal calomel electrode. A summary of research in progress, completed, or anticipated is given.
Contributing Partner: UNT Libraries Government Documents Department
ADVANCED CHEMISTRY BASINS MODEL

ADVANCED CHEMISTRY BASINS MODEL

Date: May 1, 2004
Creator: III, William Goddard; III, Lawrence Cathles; Blanco, Mario; Manhardt, Paul; Meulbroek, Peter & Tang, Yongchun
Description: The advanced Chemistry Basin Model project has been operative for 48 months. During this period, about half the project tasks are on projected schedule. On average the project is somewhat behind schedule (90%). Unanticipated issues are causing model integration to take longer then scheduled, delaying final debugging and manual development. It is anticipated that a short extension will be required to fulfill all contract obligations.
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Hiking the valleys of quatum chemistry

Hiking the valleys of quatum chemistry

Date: August 1, 2005
Creator: Aikens, Christine Marie
Description: This thesis is concerned with both the application and the extension of quantum chemical methods. Each chapter of the thesis represents a paper that has been published in or will be submitted to a scientific journal. The first three chapters of this thesis describe contributions made to chemistry through the use of quantum chemical methods, while the final two chapters illustrate the development of new methods. Chapter 2 and Chapter 3 characterize a study of the electronic structure and magnetic properties of homodinuclear titanium(III) complexes, in order to determine trends related to their potential use as molecular magnets. Chapter 2 focuses on hydride and halide bridging and terminal ligands, while Chapter 3 explores bridging ligands from other groups in the periodic table. Chapter 4 portrays a study of the solvation of glycine. Microsolvation and continuum solvation approaches are investigated in order to study the structures of small glycine-water clusters and determine the energy difference between the zwitterionic and nonionized forms of glycine, the simplest amino acid. Chapters 5 and 6 describe the implementation of analytic gradients, which are required for efficient molecular geometry optimizations, for two open-shell second-order perturbation theory methods. Chapter 5 discusses gradients for unrestricted Moeller-Plesset perturbation theory, ...
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Shock-initiation chemistry of nitroarenes

Shock-initiation chemistry of nitroarenes

Date: November 1, 1997
Creator: Davis, L.L. & Brower, K.R.
Description: The authors present evidence that the shock-initiation chemistry of nitroarenes is dominated by the intermolecular hydrogen transfer mechanism discussed previously. The acceleration by pressure, kinetic isotope effect, and product distribution are consistent with the bimolecular transition state kinetic isotope effect, and product distribution are consistent with the bimolecular transition state rather than rate-determining C-N homolysis.GC-MS analysis of samples which were subjected to a shock wave generated by detonation of nitromethane shows that nitrobenzene produces aniline and biphenyl, and o-nitrotoluene forms aniline, toluene, o-toluidine and o-cresol, but not anthranil, benzoxazinone, or cyanocyclopentandiene. In isotopic labeling experiments o-nitrotoluene and TNT show extensive H-D exchange on their methyl groups, and C-N bond rupture is not consistent with the formation of aniline from nitrobenzene or nitrotoluene, nor the formation of o-toluidine from o-nitrotoluene. Recent work incorporating fast TOF mass spectroscopy of samples shocked and quenched by adiabatic expansion shows that the initial chemical reactions in shocked solid nitroaromatic explosives proceed along this path.
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CRYSTAL CHEMISTRY OF HYDROUS MINERALS

CRYSTAL CHEMISTRY OF HYDROUS MINERALS

Date: February 2001
Creator: Zhao, Yusheng; von Dreele, Robert B.; Li, Wei & Shankland, Thomas J.
Description: Hydrogen has long been appreciated for its role in geological processes of the Earth's crust. However, its role in Earth's deep interior has been neglected in most geophysical thinking. Yet it is now believed that most of our planet's hydrogen may be locked up in high pressure phases of hydrous silicate minerals within the Earth's mantle. This rocky interior (approximately 7/8 of Earth's volume) is conjectured to contain 1-2 orders of magnitude more water than the more obvious oceans (the ''hydrosphere'') and atmosphere. This project is aimed at using the capability of neutron scattering from hydrogen to study the crystal chemistry and stability of hydrogen-bearing minerals at high pressures and temperatures. At the most basic level this is a study of the atomic position and hydrogen bond itself. We have conducted experimental runs on hydrous minerals under high pressure and high temperature conditions. The crystallographic structure of hydrous minerals at extreme conditions and its structural stability, and hydrogen bond at high P-T conditions are the fundamental questions to be addressed. The behavior of the hydrous minerals in the deep interior of the Earth has been discussed.
Contributing Partner: UNT Libraries Government Documents Department
In-Package Chemistry Abstraction

In-Package Chemistry Abstraction

Date: November 9, 2004
Creator: Thomas, E.
Description: This report was developed in accordance with the requirements in ''Technical Work Plan for: Regulatory Integration Modeling and Analysis of the Waste Form and Waste Package'' (BSC 2004 [DIRS 171583]). The purpose of the in-package chemistry model is to predict the bulk chemistry inside of a breached waste package and to provide simplified expressions of that chemistry as function of time after breach to Total Systems Performance Assessment for the License Application (TSPA-LA). The scope of this report is to describe the development and validation of the in-package chemistry model. The in-package model is a combination of two models, a batch reactor model that uses the EQ3/6 geochemistry-modeling tool, and a surface complexation model that is applied to the results of the batch reactor model. The batch reactor model considers chemical interactions of water with the waste package materials and the waste form for commercial spent nuclear fuel (CSNF) waste packages and codisposed waste packages that contain both high-level waste glass (HLWG) and DOE spent fuel. The surface complexation model includes the impact of fluid-surface interactions (i.e., surface complexation) on the resulting fluid composition. The model examines two types of water influx: (1) the condensation of water vapor that diffuses ...
Contributing Partner: UNT Libraries Government Documents Department
Chemistry implications of climate change

Chemistry implications of climate change

Date: May 1, 1997
Creator: Atherton, C.S.
Description: Since preindustrial times, the concentrations of a number of key greenhouse gases such as carbon dioxide (CO{sub 2}), methane (CH{sub 4}) and the nitric oxides (N{sub 2}O) have increased. Additionally, the concentrations of anthropogenic aerosols have also increased during the same time period. Increasing concentrations of greenhouse gases are expected to increase temperature, while the aerosols tend to have a net cooling effect. Taking both of these effects into account, the current best scientific estimate is that the global average surface temperature is expected to increase by 2{degrees}C between the years 1990 to 2100. A climate change if this magnitude will both directly and indirectly impact atmospheric chemistry. For example, many important tropospheric reactions have a temperature dependence (either Arrhenius or otherwise). Thus, if temperature increase, reaction rates will also increase.
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Reaction chemistry of cerium

Reaction chemistry of cerium

Date: January 1, 1997
Creator: unknown
Description: It is truly ironic that a synthetic organic chemist likely has far greater knowledge of the reaction chemistry of cerium(IV) than an inorganic colleague. Cerium(IV) reagents have long since been employed as oxidants in effecting a wide variety of organic transformations. Conversely, prior to the late 1980s, the number of well characterized cerium(IV) complexes did not extend past a handful of known species. Though in many other areas, interest in the molecular chemistry of the 4f-elements has undergone an explosive growth over the last twenty years, the chemistry of cerium(IV) has for the most part been overlooked. This report describes reactions of cerium complexes and structure.
Contributing Partner: UNT Libraries Government Documents Department
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