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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.
1

The chemistry of naturally occurring long chain unsaturated compounds

Silk, M H January 1954 (has links)
[From Introduction, p. 3] Raw marine oils are subject to considerable variation in composition with season and are moreover very unbalanced oils for direct use in the paint industry. Further refining is undertaken chiefly by Messrs Marine Oil Refiners of Africa Ltd., whose factory is situated at Simonstown. In their plant marine oils and others are treated by the Solexol process involving counter current extraction of the oil with liquid propane in a tower over which a temperature gradient is maintained. The process achieves the removal of a large proportion of the relatively saturated glycerides, the natural antitioxidants, and the relatively highly unsaturated components, all of which are detrimental to the eventual formation of good paint films. The segregated marine oil from the Solexol process is then bodied or polymerised at high temperatures to yield a "drying oil" which is used as a substitute for bodied linseed oil in paints. The chemical reactions taking place during the polymerisation and drying of these oils are of an exemely complex nature, and for their understanding it is necessary to have an accurate knowledge of the chemical nature of the component fatty acids in the natural glycerides ... The term "marine oils" in this work should be understood to mean marine fish body oils, marine mammal oils being excluded from consideration.
2

Effect of structural heterogeneity on liquid phase adsorption and supercritical desorption equilibria on activated carbon /

Ismadji, Suryadi. January 2002 (has links) (PDF)
Thesis (Ph. D.)--University of Queensland, 2002. / Includes bibliographical references.
3

The action of anhydrous aluminium chloride upon unsaturated organic compounds

Gangloff, Wilmer Charles, January 1917 (has links)
Thesis (Ph. D.)--Ohio state University, 1917. / Bibliography: p. 26-31.
4

The development of understanding of unsaturation in organic chemistry in the nineteenth century

Baker, Andy Albert, January 1964 (has links)
Thesis (Ph. D.)--University of Wisconsin, 1964. / Typescript. Vita. Includes bibliographical references.
5

Pore-scale investigation on mechanisms of colloid retention in unsaturated porous media

Lazouskaya, Volha. January 2009 (has links)
Thesis (Ph.D.)--University of Delaware, 2008. / Principal faculty advisor: Yan Jin, Dept. of Plant & Soil Sciences. Includes bibliographical references.
6

The peroxide effect upon the addition of hydrogen bromide to unsaturated compounds ...

Shane, Robert Samuel, January 1936 (has links)
Thesis (Ph. D.)--University of Chicago, 1933. / Lithoprinted. "Private edition, distributed by the University of Chicago libraries, Chicago, Illinois." eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.
7

A study of interaction of cyanogen bromide and unsaturated compounds especially of enolic type ...

Maizel, Benjamin Leo, January 1937 (has links)
Thesis (Ph. D.)--University of Chicago, 1932. / Lithoprinted. "Private edition, distributed by the University of Chicago libraries, Chicago, Illinois." Description based on print version record. Bibliographical foot-notes.
8

First principles studies on the adsorption of unsaturated organic molecules on reconstructed p(2x2) Si(100) surface. / 不飽和有機分子在p(2x2)重構硅(100)表面吸附的第一性原理研究 / CUHK electronic theses & dissertations collection / Bu bao he you ji fen zi zai p(2x2) chong gou gui (100) biao mian xi fu de di yi xing yuan li yan jiu

January 2009 (has links)
Styrene (C2H3-C6H5) is expected to have a more complex reaction process due to active reaction sites located in both vinyl group and phenyl group. Our exploration indicates that the adsorption products are coverage dependent. At low coverage, both vinyl group and phenyl group are possible to take part in the adsorption process. A new AsymT adsorption state covered two adjacent Si dimers is identified through two [4+2] cycloaddition. At high coverage, only vinyl group can interact with Si dimer to form cis and trans stereoisomers with different thermal energies and kinetic reaction barriers. STM images and vibrational frequencies are also explored to further support the experimental observations. / The adsorption of unsaturated organic molecules on reconstructed Si(100) surface is widely applied in the modification and functionalization of silicon surface to design new semiconductor materials. The present project is devoted to explore the adsorption mechanisms and the related properties of adsorption species for unsaturated organic molecules: acetylene (C2H 2), ethylene (C2H4), vinyl bromide (C2H 3Br) and styrene (C8H8) by quantum chemical calculation, based on density functional theory (DFT) method with pseudopotentials and plane wave basis set. / The investigation of vinyl bromide (C2H3Br) chemisorption on Si(100) resolves the conflicting conclusions between previous experimental and theoretical studies. The orientation of the vinyl bromide molecule relative to the titled silicon dimer is found to be an important factor for both the stability and reactivity of the precursor state. A new precursor pi-complex is identified, which is metastable and trapped by barriers around 0.1eV. Comparisons between theoretical and experimental vibrational frequencies support the conclusion that such a pi-complex is present on the surface at very low temperature. Careful analysis on the electronic structure also demonstrates that it is indeed a pi-complex rather than a diradical as previously suggested. Reaction mechanisms at higher vinyl bromide coverage are also modeled to explain the decrease in activation barrier observed in experiments. / The reaction processes for acetylene (C2H2) and ethylene (C2H4) chemisorption on the surface silicon dimer and the sub-layer silicon atoms are compared. Acetylene can undergo a new type of cycloaddition on sub-layer Si atoms (called sub-di-sigma) with no barrier, which is identified by ab initio Molecular Dynamics. The related properties including vibrational frequencies and STM images are calculated and found to be similar with those of the end-bridge adsorption structure. The identification of such a sub-di-sigma adsorption structure explains the discrepancy between STM experiments and theoretical calculations. In addition, the analysis of calculated vibrational frequencies, simulated STM images and the reaction barriers for di-sigma and end-bridge structures indicate that inter-dimer reaction for C2H4 is possible. / Zhang, Qiuji. / Adviser: Zhi Feng Liu. / Source: Dissertation Abstracts International, Volume: 70-09, Section: B, page: . / Thesis submitted in: October 2008. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 86-87). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.
9

The application of tandem O-H insertion/ring-closing metathesis to the synthesis of unsaturated cyclic ethers approaches to rogioloxepane and isolaurepinnacin /

Stengel, Jason H. January 2010 (has links)
Thesis (Ph.D.)--Ohio University, March, 2010. / Title from PDF t.p. Includes bibliographical references.
10

Lewis Acid Catalysed Photochemistry of Carbonyl Compounds

Duffey, Barry 11 1900 (has links)
<p> This thesis describes an investigation into the effects of Lewis acid complexation on the photochemistry of α,β unsaturated carbonyl compounds.</p> <p> Initial studies involved the use of Nuclear Magnetic Resonance (NMR) and Ultraviolet (UV) spectroscopy in examining Lewis acid modification of the photostationary state for E/Z isomerization of various acyclic enones. The results obtained provide a good understanding of the origin of the perturbation of the photostationary state of these systems. In the course of these investigations, the question also arose as to the possible effects of complexation upon the photochemistry of cyclic enone systems where E/Z isomerization cannot occur, particularly whether this would catalyze [2+2] cycloadditions to the enone carbon/carbon double bond. Lewis acid complexed enones are widely used as activated dienophiles in Diels Alder reactions, and have been recently reported to serve as activated 'enophiles' in a photochemical dimerization of coumarin.</p> </p> The examination here is focused upon endo-tricyclo [5.2.1.02,6] deca-4,8-dien-3-one. (See Diagram in thesis). </p> <p> Reported here is a detailed investigation of the photochemistry of the AlEtCl2 complex of this compound, and the results are interpreted mechanistically. The reaction gives rise to a single product which reaches a photostationary state with the reactant complex. The isomerization is formally a [1,3] sigmatropic shift involving the isolated double bond. It seems likely however, to proceed by the formation of an allyl cation intermediate.</p> / Thesis / Master of Science (MSc)

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