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High Precision Measurement of Isotope Effects on Noncovalent Host-Guest Interactions

Description: Isotope effects (IEs) are a powerful tool for examining the reactivity of, and interactions between, molecules. Recently, secondary IEs have been used to probe the nature of noncovalent interactions between guest and host molecules in supramolecular systems. While these studies can provide valuable insight into the specific interactions governing guest recognition and binding properties, IEs on noncovalent interactions are often very small and difficult to measure precisely. The Perrin group ha… more
Date: June 23, 2009
Creator: Mugridge, Jeffrey S.; Bergman, Robert G. & Raymond, Kenneth N.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Thiophene Analogs of DDT; O-Alkylhydorxylamine Hydrochorides; Dialkylaminoalkyl Esters of Phenoxyacetic Acid

Description: This thesis describes three separate and unrelated chemical experiments. The first investigates analogs for the compound DDT. The second investigates the properties of O-substituted hydroxylamines. The third investigates the action of slight changes to the structure of an antihistaminic agent.
Date: 1947
Creator: Mattison, Marjorie Bess
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Impact of Environmental Exposures on the Mutagenicity/Carcinogenicity of Heterocyclic Amines

Description: Carcinogenic heterocyclic amines are produced from overcooked foods and are highly mutagenic in most short-term test systems. One of the most abundant of these amines, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), induces breast, colon and prostate tumors in rats. Human dietary epidemiology studies suggest a strong correlation between either meat consumption or well-done muscle meat consumption and cancers of the colon, breast, stomach, lung and esophagus. For over 20 years our labora… more
Date: December 19, 2003
Creator: Felton, J S; Knize, M G; Bennett, L M; Malfatti, M A; Colvin, M E & Kulp, K S
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Colorimetric Determination of Uranium (IV)

Description: A colorimetric method was developed for the determination of uranium(IV) in the presence of uranium(VI), nitric acid, hydroxylamine sulfate, and hydrazine. A coefficient of variation of 2.4% (n = 25) was obtained. (auth)
Date: May 1, 1961
Creator: Dorsett, R. S.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Raman Studies of Molecular Dynamics and Interactions in Liquids

Description: In order to explore the N-H stretching region of aliphatic amines, we performed a study of the Raman spectrum of n-propylamine at various concentrations in cyclohexane. Statistical analysis provided evidence of a second symmetric stretching vibration, which we were able to assign to nonhydrogen bonded NH2 groups. To obtain additional evidence on the existence of monomers in n-propylamine and to further study hydrogen bonding and Fermi resonance in aliphatic amines, we extended the investigation… more
Date: May 1984
Creator: Friedman, Barry R. (Barry Richard)
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Nucleation and Growth of Atmospheric Particles

Description: New particle formation (NPF) in the atmospheric is a two-step process: Nucleation leads to the birth of stable nuclei that subsequently grow to sizes that can be detected and affect the atmosphere’s radiative properties. Our group is studying both of these processes. Our nucleation research is largely supported by NSF and involves measurements of neutral molecular clusters formed by nucleation with a new custom-designed mass spectrometer (the Cluster-CIMS) and measurements of nanoparticle size … more
Date: March 15, 2010
Creator: McMurry, P.; Kuang, C.; Barsanti, K.; Eisele, F.; Friedli, H.; Scheckman, J. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Heterocyclic Aromatic Amines in Domestically Prepared Chicken and Fish from Singapore Chinese Households

Description: Chicken and fish samples prepared by 42 Singapore Chinese in their homes were obtained. Researchers were present to collect data on raw meat weight, cooking time, maximum cooking surface temperature, and cooked meat weight. Each participant prepared one pan-fried fish sample and two pan-fried chicken samples, one marinated, one not marinated. The cooked samples were analyzed for five heterocyclic aromatic amine (HAA) mutagens, including MeIQx (2-amino 3,8-dimethylimidazo[4,5-f]quinoxaline); 4,8… more
Date: May 16, 2005
Creator: Salmon, C. P.; Knize, M. G.; Felton, J. S.; Zhao, B. & Seow, A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Synthesis of Dihydrobenzofurans via Palladium-Catalyzed Heteroannulations

Description: Palladium-catalyzed heteroannulation of 1,3-dienes with 3-iodo-2-alkenols, and 2-iodo-2-alkenols, as well as their amino analogs, affords the corresponding cyclic ethers and amines respectively. The presence of a {beta}-hydrogen in the vinylic halide results in {beta}-hydride elimination giving the corresponding alkyne. The presence of a bulky group in the {alpha}-position of the vinylic halide results in failure or reduced amounts of annulation products. A chloride source, pyridine base and el… more
Date: December 19, 2004
Creator: Rozhkov, Roman Vladimirovich
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries Government Documents Department
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Aqueous complexation of trivalent lanthanide and actinide cations by N,N,N'{sub 2},N'-tetrakis(2-pyridylmethyl)ethylenediamine.

Description: The aqueous complexation reactions of trivalent lanthanide and actinide cations with the hexadentate ligand N,N,N{prime},N{prime}-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN), have been characterized using potentiometric and spectroscopic techniques in 0.1 M NaClO{sub 4} At 25 C, the stability constant of Am(TPEN){sup 3+} is two orders of magnitude larger than that of Sm(TPEN){sup 3+}, reflecting the stronger interactions of the trivalent actinide cations with softer ligands as compared to l… more
Date: June 16, 1999
Creator: Beitz, J. V.; Ensor, D. D.; Jensen, M. P. & Morss, L. R.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Outer Sphere Adsorption of Pb(II)EDTA on Goethite

Description: FTIR and EXAFS spectroscopic measurements were performed on Pb(II)EDTA adsorbed on goethite as functions of pH (4-6), Pb(II)EDTA concentration (0.11 {micro}M - 72 {micro}M), and ionic strength (16 {micro}M - 0.5M). FTIR measurements show no evidence for carboxylate-Fe(III) bonding or protonation of EDTA at Pb:EDTA = 1:1. Both FTIR and EXAFS measurements suggest that EDTA acts as a hexadentate ligand, with all four of its carboxylate and both amine groups bonded to Pb(II). No evidence was observ… more
Date: July 16, 1999
Creator: Bargar, John R
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Heat of Dissolution Measurements for CO2 in Mixed Alkanolamine Solvents

Description: The main objective of this research was to measure heat of dissolution of CO{sub 2} in carefully mixed alkanolamine solvent systems, and provide such directly measured data that might be used for efficient design of CO{sub 2} capture process, and for better understanding of the thermodynamics of CO{sub 2}-Alkanolamine systems. An experimental set-up has been designed using the Isothermal Micro Calorimeter for measuring the solubilities and enthalpies of CO{sub 2} in mixed solvents made of MEA, … more
Date: March 17, 2007
Creator: Kabadi, Vinayak
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Mutagenic Potency of Food-Derived Heterocyclic Amines

Description: The understanding of mutagenic potency has been primarily approached using ''quantitative structure activity relationships'' (QSAR). Often this method allows the prediction of mutagenic potency of the compound based on its structure. But it does not give the underlying reason why the mutagenic activities differ. We have taken a set of heterocyclic amine structures and used molecular dynamic calculations to dock these molecules into the active site of a computational model of the cytochrome P-45… more
Date: October 26, 2006
Creator: Felton, J S; Knize, M G; Wu, R W; Colvin, M E; Hatch, F T & Malfatti, M A
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Approaches for regeneration of amine-carboxylic acid extracts

Description: Extraction processes based on reversible chemical complexation can be useful for separation of polar organics from dilute solution. Tertiary amines are effective extractants for the recovery of carboxylic acids from aqueous solution. The regeneration of aminecarboxylic acid extracts is an important step which strongly influences the economic viability of the separation process. Several regeneration methods are critically reviewed, and the factors that affect swing regeneration processes, includ… more
Date: July 1, 1995
Creator: Dai, Y. & King, C. J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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REACTIONS OF SOLVATED IONS. Final Report

Description: >Brief summaries are presented on isotopic dilution studies on salts dissolved in JCH/sub 3/OH, studies on metal and metal salts in solvents of the amine type, and studies on phosphato complexes of the pentammine Co(III) series. A list of papers published on reactions of solvated ions is included. (N.W.R.)
Date: September 24, 1962
Creator: Taube, H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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"Smart" Multifunctional Polymers for Enhanced Oil Recovery

Description: Herein we report the synthesis and solution characterization of a novel series of AB diblock copolymers with neutral, water-soluble A blocks comprised of N,N-dimethylacrylamide (DMA) and pH-responsive B blocks of N,N-dimethylvinylbenzylamine (DMVBA). To our knowledge, this represents the first example of an acrylamido-styrenic block copolymer prepared directly in homogeneous aqueous solution. The best blocking order (using polyDMA as a macro-CTA) was shown to yield well-defined block copolymers… more
Date: October 15, 2005
Creator: McCormick, Charles & Lowe, Andrew
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Synthesis and Characterization of Stimuli Responsive Block Copolymers, Self-Assembly Behavior and Applications

Description: The central theme of this thesis work is to develop new block copolymer materials for biomedical applications. While there are many reports of stimuli-responsive amphiphilic [19-21] and crosslinked hydrogel materials [22], the development of an in situ gel forming, pH responsive pentablock copolymer is a novel contribution to the field, Figure 1.1 is a sketch of an ABCBA pentablock copolymer. The A blocks are cationic tertiary amine methacrylates blocked to a central Pluronic F127 triblock copo… more
Date: December 17, 2005
Creator: Determan, Michael Duane
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries Government Documents Department
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Tandem metal-mediated synthesis

Description: This is the final report of a one-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). Boronic acids RB(OH){sub 2} are currently of interest for applications involving molecular recognition such as amine and sugar sensors and selective transport of biomolecules. They have also been shown to be powerful enzyme inhibitors and alpha-aminoboronic acids (ABAs) are particularly selective inhibitors of serine proteases. Unfortunately, current mult… more
Date: December 31, 1998
Creator: Baker, R.T.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Water-Soluble 2-Hydroxyisophthalamides for Sensitization of Lanthanide Luminescence

Description: A series of octadentate ligands featuring the 2-hydroxyisophthalamide (IAM) antenna chromophore (to sensitize Tb(III) and Eu(III) luminescence) has been prepared and characterized. The length of the alkyl amine scaffold that links the four IAM moieties has been varied in order to investigate the effect of the ligand backbone on the stability and photophysical properties of the Ln(III) complexes. The amine backbones utilized in this study are N,N,N{prime},N{prime}-tetrakis-(2-aminoethyl)-ethane-… more
Date: February 20, 2008
Creator: Samuel, Amanda P. S.; Moore, Evan G.; Melchior, Marco; Xu, Jide & Raymond, Kenneth N.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Electrospun a-Si using Liquid Silane/Polymer Inks

Description: Amorphous silicon nanowires (a-SiNWs) were prepared by electrospinning cyclohexasilane (Si{sub 6}H{sub 12}) admixed with polymethylmethacrylate (PMMA) in toluene. Raman spectroscopy characterization of these wires (d {approx} 50-2000 nm) shows 350 C treatment yields a-SiNWs. Porous a-SiNWs are obtained using a volatile polymer.
Date: December 1, 2010
Creator: Schulz, D.L.; Hoey, J.M.; Smith, J.; Lovaasen, J.; Braun, C.; Dai, X. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Electrospun a-Si using Liquid Silane/Polymer Inks

Description: Amorphous silicon nanowires (a-SiNWs) were prepared by electrospinning cyclohexasilane (Si{sub 6}H{sub 12}) admixed with polymethylmethacrylate (PMMA) in toluene. Raman spectroscopy characterization of these wires (d {approx} 50-2000 nm) shows 350 C treatment yields a-SiNWs. Porous a-SiNWs are obtained using a volatile polymer.
Date: December 9, 2010
Creator: Schulz, Doug
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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