• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 80
  • 19
  • Tagged with
  • 158
  • 158
  • 75
  • 64
  • 64
  • 35
  • 33
  • 24
  • 24
  • 17
  • 15
  • 13
  • 12
  • 11
  • 11
  • 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.
21

Hållbar utveckling i kemiundervisning. En studie ur lärarperspektiv

Salamanca Blanco, Yina Patricia January 2021 (has links)
No description available.
22

An Investigation into the Adduct Forming Potential of Drugs of Abuse with Peptides and Proteins

Gilliland, Richard Allen 29 August 2018 (has links)
Hemoglobin and serum albumin, two prevalent proteins in human blood, contain unbound cysteine thiol moieties, creating a nucleophilic site with the potential for covalent modification by reactive chemical species. These covalent modifications, called “adducts”, are stable entities that accumulate during acute and chronic exposure and remain covalently bound for the life-span of the protein. Despite their current use as exposure markers for a variety of compounds, the use of adducts in assessing exposure to drugs of abuse has not yet been explored. The goal of this work was to examine the in vitro adduct forming capability of selected drugs of abuse with hemoglobin to provide additional proof of principle for the development of a real-world detection and monitoring analysis method. This goal was accomplished by first analyzing the binding capabilities of the drugs of interest with glutathione, a smaller tripeptide. Use of protein adducts as biomarkers of drug exposure may allow for an increased window of detection, from several days to several months, as compared to current blood analysis methods. In total, there were 16 drugs analyzed in the research, and they covered a wide range of abused drugs, including cocaine, methamphetamine, and Δ 9 -THC. Results from the glutathione trials showed that 10 of the 16 the drugs of interest were able to form covalent adducts with the free thiol moiety, with four drugs forming more than one novel adduct. The MS results for hemoglobin showed 11 adducts formed for five of the drugs under investigation. Additional MS/MS confirmatory data was obtained for two of those 11 adducts. I successfully identifyied adducts formed between drugs of abuse and glutathione and hemoglobin, which have the potential to be used as long-term biomarkers of exposure.
23

Hydration of Propylene to Isopropanol

Diala, Nehemiah 01 January 1987 (has links) (PDF)
The hydration of propylene to isopropanol was investigated. The first part of this study concerned the direct hydration reaction in various liquid phase systems in the presence of sulfuric acid or p-toluenesulfonic acid. The second part in a two-stage process in which propylene was contacted with excess acetic acid to form isopropyl acetate; the ester was then hydrolyzed to isopropyl alcohol and acetic acid.
24

The Synthesis of 2-Aryl-3-Fluoroalkoxy-1-Propenes and Some Potentially Useful Reaction of These Systems

Brown, Joan E. 01 January 1987 (has links) (PDF)
This report discusses research involving the fluoroalkoxylation of 2-arylprop-1-en-3-yltrimethylammonium iodides and the useful synthetic application of the adducts formed. The present work includes: 1) reactions of several 2-arylprop-1-en-3-yltrimethylammonium iodides with the sodium salt of 2,2,2-trifluoroethanol; 2) reactions of several fluoroalkoxy alcohols with 2-(4-bromophenyl)prop-1-en-3-yltrimethylammonium iodide; and 3) the oxidation of 2-(4-chlorophenyl)-3-(2,2,2-trifluoroethyoxy)-1-propene using the Lemieux/von Rudloff reagent. This report reveals the experimental conditions and procedures used as well as spectral and physical data of all new compounds synthesized. Explanation is offered for a possible mechanism for the formation of these compounds and recommendations for future research are given.
25

Preparation of Geminal Diflourodienes

Landavazo, Antonio 01 January 1987 (has links) (PDF)
This report discusses research involving the preparation of germinal difluorodienes. Free radical addition of dibromodifluoromethane to 1-hexene and cyclohexene was performed, followed by a double dehydrohalogenation to yield 1,1-difluoro-1,3-heptadiene and 3-(difluoromethylene)cyclohexene, respectively. NMR, IR, and mass spectral data were obtained and presented as groundwork for further research. A study comparing the free radical initiators, benzoyl peroxide and 2,2’-azobis-(2-methyl)proprionitrile (AIBN) was included, showing neither as ideal initiators for the free radical additions performed. The relative stabilities of the bromodifluoromethyl and the difluoroiodomethyl radicals were approximated. A Diels-Alder reaction of 1,1-difluoro-1,3-heptadiene with 4-phenyl-1,2,4-triazoline-3,5-dione produced the expected [4 + 2] cycloadduct in good yield.
26

Waste minimization and treatment for ammonium bifluoride

Bowes, G. Thad 01 January 1995 (has links)
No description available.
27

New catalyst systems for the vapor phase synthesis of carbon filaments

Bratescu, Daniela 01 January 1995 (has links)
No description available.
28

The use of ultrasound to enhance the degradation rate of chlorinated aliphatics and to study their sorption properties on elemental iron surfaces

Toy, Patrick Christopher 01 January 1998 (has links)
No description available.
29

Examination of a pyrrole cyclization reaction for the formation of 4-carbethoxy-2-phenacl-3-phenyl-pyrrole : synthesis of a series of novel pyrrole analogs that contain the diacylhydrazide group

Diebes, Anthony 01 January 1996 (has links)
No description available.
30

Carbon dioxide hydrogenation over group VIII metals supported on graphite/

Kweyete, Albert Duana 01 January 1992 (has links)
No description available.

Page generated in 0.0753 seconds