• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 105
  • 99
  • 25
  • 12
  • 6
  • 5
  • 4
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • Tagged with
  • 318
  • 87
  • 38
  • 32
  • 31
  • 23
  • 21
  • 19
  • 19
  • 18
  • 17
  • 17
  • 17
  • 16
  • 16
  • 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.
31

Disposable amperometric sensors for environmental monitoring

Chang, Seung Cheol January 2000 (has links)
No description available.
32

Synthetic and mechanistic studies of arylsilane oxidation

Rayment, Elizabeth January 2013 (has links)
In this thesis, we study arylsilane oxidation from both a synthetic and a mechanistic perspective. Building upon previous work within our group, we demonstrate in an early chapter that arylhydrosilanes are surprisingly reactive to oxidation. This disproves the previous assumptions of the Tamao oxidation and provides new insights into the mechanism of the reaction. Furthermore, we find that the best substrates for oxidation are arylmethoxysilanes, and we describe rapid and efficient syntheses for these compounds. A further chapter addresses applications of arylsilane oxidation to natural product synthesis, protecting group chemistry and cycloadditions. By collecting concentration profiles of the oxidation of various arylsilanes, we reveal a rapid equilibration between arylmethoxysilanes and arylsilanols. By comparison, phenol formation (especially from silanol) is often slow. The rate of oxidation turns out to be highly sensitive to both the concentration of the oxidising agent and the substituents of the aromatic ring. In the final chapter we discuss in detail the consequences of these observations for the mechanism of arylsilane oxidation.
33

Isolation and structural elucidation of tyrosinase inhibitors from five plant extracts

Zheng, Zongping., 郑宗平. January 2011 (has links)
published_or_final_version / Biological Sciences / Doctoral / Doctor of Philosophy
34

Determination and fate of organic pollutants in the environment

Hancock, Andrew Paul January 1999 (has links)
Different sample preparation methodologies were evaluated for the determination of pollutants in different matrices. The methods investigated were chosen on the merits of decreased sample preparation time and low toxic solvent consumption with the aim to provide viable alternatives to more laborious methods, such as, Soxhlet extraction. Techniques were developed to extract and quantify organic pollutants from contaminated soils and water. The results from shake flask extraction of aged phenolic contaminated soils were used in attempt to relate sorption to both the soil, and pollutant properties. This was to help gain an understanding of the transport and fate of phenols in different environmental situations. The partitioning (sorption/desorption) of radiolabelled phenols between aqueous solution and soil was investigated using a modified shake flask technique. This provides additional information which can be related to soil characteristics, hence pertaining to the fate mechanisms involved for phenols in the environment. The results from these investigations suggest that more than one factor contributes to the sorption of phenols in soils.
35

Catalysis deactivation in staged direct coal liquefaction

McQueen, Paul January 1996 (has links)
No description available.
36

Protein cross-linking with oxidative enzymes and transglutaminase : effects in meat protein systems /

Lantto, R. January 1900 (has links) (PDF)
Thesis (doctoral)--University of Helsinki, 2007. / Includes bibliographical references. Also available on the World Wide Web.
37

Microbial transformation of 3-nitro-4-hydroxybenzene arsonic acid (roxarsone)

Crable, Bryan. January 2007 (has links)
Thesis (M.S.)--Duquesne University, 2007. / Title from document title page. Abstract included in electronic submission form. Includes bibliographical references (p. 101-104) and index.
38

Herstellung von 1,2-Dihydro-1,2-dihydroxybenzoat aus Toluol Konstruktion von Stämmen für die selektive Hydroxylierung /

Gittinger, Simone. January 2003 (has links)
Stuttgart, Univ., Diss., 2002.
39

Studies of enzyme-catalysed reactions of phenols and related compounds

Chalmers, Brian January 1970 (has links)
No description available.
40

A tyramine hydroxylase system from bananas (Musa sapientum L.).

Deacon, William Harold 01 January 1967 (has links) (PDF)
No description available.

Page generated in 0.0429 seconds