• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 19
  • 4
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 29
  • 29
  • 8
  • 7
  • 4
  • 3
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Development of efficient oxidizing agents for disinfection, pollutant degradation and peptide modification

Chan, Tak-chung. January 2008 (has links)
Thesis (Ph. D.)--University of Hong Kong, 2008. / Includes bibliographical references (leaf 185-187) Also available in print.
12

Chemical approaches to probe environmental stress in Archaea

Tarlykov, Pavel Victorovich. January 2009 (has links) (PDF)
Thesis (MS)--Montana State University--Bozeman, 2009. / Typescript. Chairperson, Graduate Committee: Brian Bothner. Includes bibliographical references (leaves 63-71).
13

Estudos sobre a aplicação de óxido de nióbio em reações de oxidação de compostos orgânicos /

Carvalho, José Henrique Lázaro January 2018 (has links)
Orientador: Luiz Carlos da Silva Filho / Banca: Bruno José Gonçalves da Silva / Banca: Gilbert Bannach / Resumo: Os hidrocarbonetos se constituem na função mais simples da química orgânica. Mesmo sendo formados apenas por carbono e hidrogênio, esta classe é uma das mais diversas, onde se destacam os hidrocarbonetos alquil aromáticos (HAA) e os hidrocarbonetos aromáticos policíclicos (HAP). Por possuírem baixa reatividade e serem lipossolúveis, os HAA e HAP tendem a se acumular na natureza e nos tecidos vivos podendo levar a mutações genéticas e ao câncer. Funcionalizações oxigenadas nestes hidrocarbonetos ampliam suas aplicações industriais e auxiliam na sua remediação ambiental. A oxidação radicalar utilizando radicais hidroxila via TBHP (t-butil-hidroperóxido) é uma rota promissora devido à ausência de resíduos metálicos nocivos no processo. Paralelamente, o uso de metais do bloco-d, como o nióbio, como catalisadores heterogêneos, que são conhecidos por apresentarem boa estabilidade térmica, porosidade, maior superfície de contato e podendo ser recuperado e reutilizado, vem sendo descrito como bons catalisadores para a reação, permitindo rendimentos maiores e condições reacionais mais brandas. O nióbio tem despertado o interesse de muitos grupos de pesquisa devido às suas propriedades e aplicabilidades na metalurgia, supercondutores e supercapacitores, e na síntese orgânica. Este trabalho focou no estudo da aplicação do óxido de nióbio como catalisador heterogêneo em reações de oxidação de HAA e HAP usando o TBHP como oxidante. Diferentes variáveis reacionais como o solvente, a concen... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Hydrocarbons are the simplest function of organic chemistry. Although formed only by carbon and hydrogen, this class is one of the most diverse, in which the alkyl aromatic hydrocarbons (AAHs) and the polycyclic aromatic hydrocarbons (PAHs) stand out. These substances are mostly fossil raw materials widely used in industry in diverse applications. Because they have low reactivity and are liposoluble, AAHs and PAHs tend to accumulate in nature and in living tissues, leading to genetic mutations and cancer. Oxygenated functionalities in these hydrocarbons broaden their industrial applications and assist in their environmental remediation. Radical oxidation using hydroxyl radicals via TBHP (t-butylhydroperoxide) is a promising route due to the absence of noxious metal residues in the process. At the same time, the use of d-block metals, such as niobium, as heterogeneous catalysts, which are known to have good thermal stability, porosity, larger contact surface and be able to be recovered and reused, have been described as good catalysts for the reaction, allowing for higher yields and softer reaction conditions. Niobium has attracted the interest of many research groups because of its properties and applications in metallurgy, superconductors and supercapacitors, and in organic synthesis. This work focused on the study of the application of niobium oxide as a heterogeneous catalyst in oxidation reactions of AAHs and HAP using TBHP as oxidant. Many reactional variables like the s... (Complete abstract click electronic access below) / Mestre
14

Analysis of flame images in gas-fired furnaces

Cokrojoyo, Handi, January 2007 (has links)
Thesis (Ph.D.)--University of Missouri-Columbia, 2007. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on March 19, 2009) Vita. Includes bibliographical references.
15

Arabinofuranose 1-deoxy-[beta]-1-C-sulfonic acid

Won, Walter S. January 2008 (has links)
Thesis (M.S.)--Rutgers University, 2008. / "Graduate Program in Chemistry and Chemical Biology." Includes bibliographical references (p. 23-24).
16

Lipoxygenase activity in menhaden (Brevoortia tyrranus) and its contribution to oxidation of omega-3 polyunsaturated fatty acids in menhaden oil /

Grun?, Ingolf U., January 1993 (has links)
Thesis (Ph. D.)--Virginia Polytechnic Institute and State University, 1993. / Vita. Abstract. Includes bibliographical references (leaves 165-181). Also available via the Internet.
17

Polyunsaturated fatty acids, lipid accumulation, and oxidant stress in cells in culture /

Gavino, Victor Cruz January 1981 (has links)
No description available.
18

Oxidation addition of H-H bonds to iridium: developing novel active water soluble catalysts for hydrogenation of unsaturates

Le, Trang X. 23 September 2008 (has links)
The oxidative addition of H-H to iridium(l) trimethylphosphine complexes was studied and the reactivity of the resulting water soluble dihydrido iridium (III) complexes was investigated. One Dihydrido iridium(III) complex, mer-Ir(H)₂(PMe₃)₃CI <b>(2)</b> was characterized by ¹H, ³¹p and ¹³C NMR spectroscopy, CH analysis and single crystal xray diffraction. <b>(2)</b> reacted with the strong sigma donor PMe₃ to form [IrH2(PMe₃)4]CI <b>(3b)</b> without having to remove the chloride ligand. <b>(2)</b> reacted with monosubstituted acetylenes and an internal diyne in water to form the vinyl complexes Ir(H)(C(R')=C(H)-(R))(PMe₃)₃CI (R = CMe₃, C₆H₅, SiMe₃, R' = H, <b>(4)-(6);</b> R' = CCMe₃, R= Me, <b>(7)). (2)</b> also reacted in water with ethynylpyridine to form an unusual metallacycle "trimer" <b>(8)</b>. A mechanism for tltrimerizationtl is proposed. <b>(2)</b> also reacted with ethylene in water to form the diethyl iridium complex Ir(CH₂CH₃)₂(PMe₃)₃CI <b>(8)</b>. Encouraged by these results, catalytic hydrogenation of unsaturates in water was investigated. It was found that <b>(2)</b> is active as a water soluble catalyst for hydrogenation of unsaturates. A mechanism for catalytic hydrogenation was proposed. / Ph. D.
19

The kinetics of the chromic acid oxidation of acetaldehyde

McCarthy, Edward Raymond January 1952 (has links)
The kinetics for the reaction of the oxidation of acetaldehyde by chromic acid in aqueous medium has been studied in an attempt to extend the present knowledge of oxidation by chromic acid. In particular, these experiments were undertaken in order to see if there are any similarities between this reaction and the oxidation of isopropyl alcohol in aqueous medium, which other investigators have studied. The main runs were carried out at 25°, at an ionic strength of 0.3. The reaction was followed by the decrease in chromic acid concentration as determined with the Beckman Spectrophotometer. In all of the runs, the concentrations of acetaldehyde and H⁺ were in excess of the chromic acid concentrations. It was found that the oxidation of acetaldehyde is first order in acetaldehyde and first order in HCrO₄⁻, (but not strictly first order in total chromic acid). The reaction is roughly second order in H⁺. Mn⁺² has an inhibitory effect upon the rate, as has been found in the isopropyl alcohol oxidation. Because of the similarity in kinetic behavior between acetaldehyde and isopropyl alcohol, the mechanisms are probably very similar. This mechanism for acetaldehyde oxidation has been discussed in some detail. / Master of Science
20

Effect of oxidized and hyperoxidized guanine on DNA primer-template structures.

January 2009 (has links)
Fenn, Dickson. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 74-81). / Abstract also in Chinese. / Title Page --- p.i / Thesis Committee --- p.ii / Acknowledgement --- p.iii / Table of Contents --- p.v / List of Tables --- p.ix / List of Figures --- p.x / List of Abbreviations and Symbols --- p.xv / Abstract --- p.xvii / Chapter 1.Chapter One: --- Introduction --- p.1 / Chapter 1.1 --- Oxidation and Hyperoxidation of Guanine --- p.1 / Chapter 1.2. --- DNA Replication --- p.2 / Chapter 1.3 --- Mutagenesis --- p.3 / Chapter 1.4 --- Literature Survey on Spiroiminodihydantoin (Sp) --- p.4 / Chapter 1.5 --- Purpose of This Work --- p.5 / Chapter 1.6 --- DNA Structure --- p.6 / Chapter 1.6.1 --- Nomenclature --- p.6 / Chapter 1.6.2 --- Torsion Angles --- p.6 / Chapter 1.6.3 --- Sugar Pucker Conformation --- p.7 / Chapter 1.6.4 --- Secondary Structures of DNA --- p.8 / Chapter 2.Chapter Two: --- Materials and Methodology --- p.10 / Chapter 2.1 --- Sample Design --- p.10 / Chapter 2.2 --- Sample Preparation --- p.11 / Chapter 2.2.1 --- DNA Synthesis and Purification --- p.11 / Chapter 2.2.2 --- HPLC Separation --- p.11 / Chapter 2.2.3 --- NMR Samples Preparation --- p.12 / Chapter 2.3 --- NMR Analysis --- p.12 / Chapter 2.3.1 --- Resonance Assignment --- p.14 / Chapter 2.3.1.1 --- Proton --- p.14 / Chapter 2.3.1.2 --- Phosphorous --- p.16 / Chapter 2.3.2 --- Sugar Pucker Conformation --- p.17 / Chapter 2.3.3 --- Backbone Conformation --- p.18 / Chapter 2.4 --- UV Melting Analysis --- p.19 / Chapter 3.Chapter Three: --- "HPLC, NMR and UV Results" --- p.21 / Chapter 3.1 --- HPLC Separation of Sp Diastereoisomers --- p.21 / Chapter 3.2 --- NMR Resonance Assignments --- p.24 / Chapter 3.2.1 --- 5'-GG Sample --- p.24 / Chapter 3.2.2 --- 5'-G(oG) Sample --- p.26 / Chapter 3.2.3 --- 5'-G(Sp) Sample --- p.29 / Chapter 3.2.4 --- 5'-T(oG) Sample --- p.31 / Chapter 3.2.5 --- 5'-T(Sp) Sample --- p.34 / Chapter 3.3 --- Sugar Pucker Conformation --- p.38 / Chapter 3.4 --- Backbone Conformation --- p.41 / Chapter 3.5 --- UV Melting --- p.43 / Chapter 4.Chapter Four: --- Effect of Spiroiminodihydantoin and 7-hydro-8-oxoguanine on Primer-Template Structures --- p.44 / Chapter 4.1 --- Overview --- p.42 / Chapter 4.2 --- NMR Investigations of the Primer-Template Models --- p.45 / Chapter 4.2.1 --- Incorporation of a dCTP Opposite a 5'-GG Template --- p.45 / Chapter 4.2.2 --- Incorporation of a dCTP Opposite a 5'-G(oG) Template --- p.46 / Chapter 4.2.3 --- Incorporation of a dCTP Opposite a 5'-G(Sp) Template --- p.48 / Chapter 4.2.4 --- Incorporation of a dATP Opposite a 5'-T(oG) Template --- p.50 / Chapter 4.2.5 --- Incorporation of a dATP Opposite a 5'-T(Sp) Template --- p.51 / Chapter 4.3 --- Effect of Sp and oG on Primer-Template Structures --- p.52 / Chapter 4.3.1 --- Misaligned Structure with a Sp-Bulge --- p.52 / Chapter 4.3.2 --- C·oG Base Pair in 5'-G(oG) --- p.54 / Chapter 4.3.3 --- Biological Implications --- p.54 / Chapter 5. --- Chapter Five: Preliminary Structural Calculations on Primer- Template Structures --- p.56 / Chapter 5.1 --- Experimental Restraints Extraction --- p.56 / Chapter 5.2 --- Experimental Restraints Distribution --- p.58 / Chapter 5.3 --- Structural Calculations --- p.60 / Chapter 5.4 --- Structural Results --- p.62 / Chapter 5.4.1 --- 5'-GG --- p.63 / Chapter 5.4.2 --- 5'-G(oG) --- p.64 / Chapter 5.4.3 --- 5'-T(oG) --- p.65 / Chapter 5.4.4 --- 5'-T(SpR) with 5'-T(Spl) Restraints --- p.66 / Chapter 5.4.5 --- 5'-T(SpR) with 5'-T(Sp2) Restraints --- p.67 / Chapter 5.4.6 --- 5'-T(SpS) with 5'-T(Spl) Restraints --- p.68 / Chapter 5.4.7 --- 5'-T(SpS) with 5'-T(Sp2) Restraints --- p.69 / Chapter 5.6 --- Structural Analysis --- p.70 / Chapter 6. --- Chapter Six: Conclusions and Future Work --- p.72 / Appendix --- p.73 / References --- p.74

Page generated in 0.0806 seconds