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  • 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

The distribution of organochlorine pesticides among milk components

Hugunin, Alan Godfrey, January 1970 (has links)
Thesis (M.S.)--University of Wisconsin--Madison, 1970. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.
32

Determination of the rate of contaminant oxidations by permanganate : implications for in situ chemical oxidation (ISCO) /

Waldemer, Rachel H. January 2004 (has links)
Thesis (M.S.)--OGI School of Science & Engineering at OHSU, 2004. / Includes bibliographical references (leaves 59-65).
33

Formation and reactions of ipso adducts from chlorination of 2-methyl-2-aryloxypropanoic acids

Ji, Ruizhi 20 June 2018 (has links)
Chlorination of 2-methyl-2-aryloxypropanoic acids with aqueous hypochlorous acid gives spiro chloro adducts in moderate to high yields. In chlorination of 2-methyl-2-(2-methylphenoxy)propanoic acids, 1,2-adducts are formed, while in the case of 2-methyl-2-(4-methylphenoxy)propanoic acids, 1,4-adducts are obtained. In addition to the spiro adducts, 2-methyl-2-(4-chlorophenoxy)propanoic acids in the former case, and 2-methyl-2-(2-chlorophenoxy)propanoic acids in the latter case are formed, respectively. No 6-chlorosubstituted products are detected on chlorination of any of the substrates. Chlorination of 2-methyl-2-(2,4-dimethylphenoxy)propanoic acid affords only the 1,4-adduct. However, chlorination of 2-methyl-2-(5-chloro-2,4-dimethylphenoxy)propanoic acid gives both the 1,2- and the 1,4-adduct. 2-Methyl-2-(3,5-di-t-butylphenoxyl)propanoic acid on chlorination yields the diastereomeric secondary chloro adduct, 8-chloro-7,9-di-t-butyl-3,3-dimethyl-1,4-dioxaspiro (4,5) deca-6,9-dien-2-one. Under neutral and non-polar conditions, most of the 1,2-adducts undergo a thermal rearrangement of the chlorine which is shown to be a (1,5) sigmatropic chlorine shift. The rearrangement rates are highly dependent on the nature of the substituents in the diene systems. Under acidic and non-nucleophilic conditions, most of the 1,4-adducts undergo an intramolecular 1,2 chlorine shift followed by aromatization to give the 3-chloro-substituted products. For the dienes in which the 3-position is originally substituted, successive 1,2 chlorine migrations and/or side chain substitution are observed. On the other hand, the 1,2-adducts under similar reaction conditions undergo an intermolecular 1,4 chlorine shift to give the 5-chlorosubstituted products. In the case that the 5-position is substituted by a methyl group, side chain substitution at the 5-methyl takes place. In the presence of added base, solvolyses of the 1,4-adducts in methanol affords simple solvolysis products and/or 1,2 carboxyl rearranged products. The kinetic studies of the solvolyses of the 1,4-adducts have been carried out. The results reveal the substituent effects on both the simple solvolysis displacement and the rearrangement reactions. / Graduate
34

Ex ante assessment of secondary impacts of environmental regulation: case study--organochlorines in the Canadian pulp and paper industry

Inch, Hilary 11 1900 (has links)
This thesis examines how the secondary effects of environmental regulations are assessed before the regulations are proclaimed. Negative secondary effects of a policy (such as regulation) may outweigh direct benefits; it is important that secondary effects are clearly assessed. The case study is the control of organochlorines in the Canadian pulp and paper industry via federal regulation of dioxins and furans and British Columbia's regulation of Adsorbable Organic Halogen (AOX). The thesis is founded upon the premise that sustainability must be an integral consideration. A systems approach is used to evaluate assessments and to generate recommendations. The evaluation is divided into two parts: the process of assessing the regulation and the contents of the assessments. Background information is provided on organochlorines, pulp and paper making, the pulp and paper industry and the relevant regulatory processes. A chronology of the regulation is established. Assessments are reviewed from five classes of stakeholders: industry, labour, environmentalists, the federal government and the British Columbia government. The study found that secondary impacts of the regulation were less important than the primary action, which was managing the risk posed by organochlorines in effluent. For the secondary assessments, stakeholders felt problems with the process were greater than shortcomings in content. In particular, governments' lack of response to submissions caused a lack of confidence in the system, which was well-founded in British Columbia's highly political process. The federal Regulatory Impact Analysis Statements gave a valuable but limited summary of impact assessments and the rationale behind the regulations. To improve the process of creating environmental regulation I recommend that the federal government assemble a reference document for assessments, that all levels of government institute class assessments for general cases, and that all stakeholders use a consistent, multiobjective framework. The proposed framework is presented. / Graduate and Postdoctoral Studies / Graduate
35

Organochlorine contaminants in fish and snails from three U. S. Arctic freshwater lakes

Wilson, Rose 10 June 1994 (has links)
Graduation date: 1995
36

Characterisation of an 84 kb linear plasmid that encodes DDE cometabolism in Terrabacter sp. strain DDE-1

Shirley, Matt, n/a January 2006 (has links)
DDT, an extremely widely used organochlorine pesticide, was banned in most developed countries more than 30 years ago. However, DDT residues, including 1,1-dichloro-2,2-bis(4-chlorophenyl)ethylene (DDE), still persist in the environment and have been identified as priority pollutants due to their toxicity and their ability to bioaccumulate and biomagnify in the food chain. In particular, DDE was long believed to be &quotenon-biodegradable&quote, however some microorganisms have now been isolated that are able to metabolise DDE in pure culture. Terrabacter sp. strain DDE-1 was enriched from a DDT-contaminated agricultural soil from the Canterbury plains and is able to metabolise DDE to 4-chlorobenzoic acid when induced with biphenyl. The primary objective of this study was to identify the gene(s) responsible for Terrabacter sp. strain DDE-1�s ability to metabolise DDE and, in particular, to investigate the hypothesis that DDE-1 degrades DDE cometabolically via a biphenyl degradation pathway. Catabolism of biphenyl by strain DDE-1 was demonstrated, and a biphenyl degradation (bph) gene cluster containing bphDA1A2A3A4BCST genes was identified. The bphDA1A2A3A4BC genes are predicted to encode a biphenyl degradation upper pathway for the degradation of biphenyl to benzoate and cis-2-hydroxypenta-2,4-dienoate and the bphST genes are predicted to encode a two-component signal transduction system involved in regulation of biphenyl catabolism. The bph gene cluster was found to be located on a linear plasmid, designated pBPH1. A plasmid-cured strain (MJ-2) was unable to catabolise both biphenyl and DDE, supporting the hypothesis that strain DDE-1 degrades DDE cometabolically via the biphenyl degradation pathway. Furthermore, preliminary evidence from DDE overlayer agar plate assays suggested that Pseudomonas aeruginosa carrying the strain DDE-1 bphA1A2A3A4BC genes is able to catabolise DDE when grown in the presence of biphenyl. A second objective of this study was to characterise pBPH1. The complete 84,054-bp sequence of the plasmid was determined. Annotation of the DNA sequence data revealed seventy-six ORFs predicted to encode proteins, four pseudogenes, and ten gene fragments. Putative functions were assigned to forty-two of the ORF and pseudogenes. Besides biphenyl catabolism, the major functional classes of the predicted proteins were transposition, regulation, heavy metal transport/resistance, and plasmid maintenance and replication. It was shown that pBPH1 has the terminal structural features of an actinomycete invertron, including terminal proteins and terminal inverted repeats (TIRs). This is the first report detailing the nucleotide sequence and characterisation of a (linear) plasmid from the genus Terrabacter.
37

Occurrence of organochlorine compounds in a forest bog at Stubbetorp, Kolmården : -Indication for a natural formation? / Förekomst av organiska klorämnen i en skogsmosse vid Stubbetorp, Kolmården : - Indikation på en naturlig formation?

Hoppe, Sabina, Thomsen, Frida January 2005 (has links)
<p>Volatile organochlorine compounds emitted from natural sources can participate in environmentally relevant processes affecting life on Earth, such as stratospheric ozone destruction and warming of the troposphere. The aim of this study was to investigate if forest bogs contribute to the environmental input of naturally produced volatile organochlorine compounds. The concentrations of four different volatile organochlorine compounds were determined in ambient air, rainwater, surface water, and sub-surface water. For chloroform, up to 10-times higher concentrations were detected in the surface water compared to the sub-surface water taken at 40 cm depth. As the concentrations of chloroform in rainwater where almost in the same range as the concentrations in the sub-surface water, a formation of chloroform is suggested in the surface water. The results of this study indicate forest bogs as a possible new natural source for the input of volatile organochlorine into the environment.</p>
38

Effects of substrate interactions, toxicity, and bacterial response during cometabolism of chlorinted solvents by nitrifying bacteria

Ely, Roger L. 05 January 1996 (has links)
Graduation date: 1996
39

Occurrence of organochlorine compounds in a forest bog at Stubbetorp, Kolmården : -Indication for a natural formation? / Förekomst av organiska klorämnen i en skogsmosse vid Stubbetorp, Kolmården : - Indikation på en naturlig formation?

Hoppe, Sabina, Thomsen, Frida January 2005 (has links)
Volatile organochlorine compounds emitted from natural sources can participate in environmentally relevant processes affecting life on Earth, such as stratospheric ozone destruction and warming of the troposphere. The aim of this study was to investigate if forest bogs contribute to the environmental input of naturally produced volatile organochlorine compounds. The concentrations of four different volatile organochlorine compounds were determined in ambient air, rainwater, surface water, and sub-surface water. For chloroform, up to 10-times higher concentrations were detected in the surface water compared to the sub-surface water taken at 40 cm depth. As the concentrations of chloroform in rainwater where almost in the same range as the concentrations in the sub-surface water, a formation of chloroform is suggested in the surface water. The results of this study indicate forest bogs as a possible new natural source for the input of volatile organochlorine into the environment.
40

Sorption of 2,4-dichlorophenol and 2,4,5-trichlorophenol by softwood fibers

Severtson, Steven J. 01 January 1995 (has links)
No description available.

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