Physical and geochemical tracer measurements were collected at one oceanographic station (Station A: 72 N 143 W) in the southern Canada Basin from 1989 to 1995, along sections from the Beaufort Shelf to this station in 1993 and 1995, and along a section westward of Banks Island in 1995. These measurements were examined to see how recent events in three upstream Arctic Ocean sub-basins impacted upon Canada Basin waters. Upstream events included Atlantic layer warming, relocation of the Atlantic/Pacific water mass boundary, and increased ventilation of boundary current waters. Early signals of change appeared first in the Canada Basin in 1993 along the continental margin and, by 1995, were evident at Station A in the basin interior and farther downstream. Differences in physical and geochemical properties (nutrients, oxygen, ¹²⁹I and CFCs) were observed throughout much of the water column to depths greater than 1600 m. In particular, the boundary distinguishing Pacific from Atlantic-origin water was found to be shallower and Atlantic-origin water occupied more of the Canada Basin water column. By 1995, Atlantic-origin water in the lower halocline at Station A was found to be colder and more ventilated. Likewise, within the Atlantic layer, Fram Strait Branch (FSB) water was colder, fresher, and more ventilated, and Barents Sea Branch (BSB) water was warmer, fresher, and more ventilated than during previous years. By comparing observations at Station A with eastern Nansen Basin observations, the main source of these changes was traced to dense water outflow from the Barents Sea. Studies indicated that in early 1989 Barents Sea waters were 2°C warmer and that, between 1988 and 1989, a large volume of dense water had left the shelf. These events coincided with an atmospheric shift to increased cyclonic circulation in 1989, a transition unprecedented in its magnitude, geographic reach, and apparent oceanographic impact. The effects of a large outflow of dense Barents Sea water were observed some 5000 km away downstream in the Canada Basin where the BSB component of the Atlantic layer had increased 20% by 1995. / Graduate

M.Sc. / Molecules containing a long saturated carbon chain are present in many natural and commercial products. Due to the conformational flexibility of the carbon chain, different molecular conformations of these molecules are possible resulting in polymorphism. The crystal structure of a material greatly influences its chemical and physical properties, leading to different properties for different polymorphs. Designing materials with specific properties requires the understanding of the underlying fundamental parameters and forces influencing the packing of molecules in the crystal. A thorough literature study was conducted to determine the crystallographic research that has been done long chain compounds. Not only did this literature study lead to the identification of possible research fields, but also provided a solid background concerning the crystallographic behavior of these systems. In this project we investigated the polymorphism of simple molecules containing a saturated carbon chain with seventeen or eighteen carbons. Two systems are investigated namely n-alkylammonium halides and esters of fatty acids. By varying crystallization conditions different polymorphs of each compound can be obtained. Various experimental techniques were employed to shed light on the structure and packing of the long chain molecules in the different polymorphs. The crystal structure of the low temperature polymorph of n-octadecylammonium bromide was determined, as well as the cell dimensions of the low temperature form of noctadecylammonium chloride. The unit cell dimensions of n-octadecylammonium iodide monohydrate was also determined. The structures of the methyl and ethyl esters of noctadecanoic acid and the symmetrical -ester heptadecyl-heptadecanoate was investigated. In this project a young, dynamic research field was investigated. This led to the identification of other possible fields of study. Because there are not many reports in the literature on the crystallographic characteristics of these compounds, the evolving of the project required a lot of creativity.

Masters of Science / Following successful discovery and production of hydrocarbons, Gabon is one of the key hydrocarbon target countries in Africa. Located in the Lower Congo Basin, the study area is based in Etame Marin Permit (EMP), which is licensed to VAALCO Energy Inc., and has been producing hydrocarbons since 2002. The currently explored and producing reservoirs are in the pre-salt sandstones of the Aptian Gamba Formation, charged with hydrocarbons sourced from the syn-rift lacustrine shale of the pre-Aptian Melania Formation. With the aim of finding potential petroleum plays in the post-salt successions and by using 3D prestack depth migration (PSDM) seismic sections and wireline logs, a detailed study of the post- Aptian stratigraphy and salt tectonics of the EMP was undertaken. Eight distinct reflectors were identified based on gamma ray signatures, stratal terminations and isopach trends. Sediment distribution patterns and the relative sea level history of the succession were determined by applying principles of sequence stratigraphy and salt tectonics. Furthermore, two potential plays have been outlined in the post-salt carbonates of the Albian Madiela Formation as well as in sandstones of the Turonian Azile Formation. These reservoirs might have been charged with hydrocarbons from the pre-salt shale of the Melania Formation and/or potentially also enriched from the Albian and Cenomanian shales. For these post-salt hydrocarbon reservoirs to be charged by the pre-salt source rocks, windows within the extensive evaporitic sealing of the Aptian Ezanga Formation were required. 3D PSDM seismic sections attest that diapirism of the Aptian salt unit generated ample hydrocarbon migration pathways from the pre-salt source rocks to post-salt reservoirs. Five well-developed potential salt windows have been identified, two of which have good probability to have facilitated the upward migration of hydrocarbons, because these salt windows are located up dip of oil producing wells. However, even if hydrocarbons are found in the post-salt reservoirs, similarly to the Yombo Field (located offshore Congo, south of the EMP), these shallow reservoirs in the EMP are likely to produce heavy oils due to biodegradation.

No description available.

The thermal decomposition of cyclobutane is a homogeneous,unimolecular reaction;ethylene being the only product.The rate law :- K = 10¹⁵•³ e⁻⁶¹’⁰⁰⁰[symbol omitted] sec.⁻¹ was found to be obeyed in the pressure region 10 to 40 mm. and temperature range 398° to 450°C. Cyclobutane undergoes a wall reaction to form propylene and 1-butene. The high pressure rate constant falls off at low pressures and reaches a limiting low pressure rate when activation is maintained by collision with the walls of the reactor. The low pressure limiting rate decreases as the size of the reactor increases. The fall off curves gave best agreement with values of the Slater parameter, n, between 5 and 8, and values of the Kassel parameter, s, between 3 and 7. It was concluded that the ring vibrations are of major importance in the dissociation, and that the C—H bond vibrations are relatively unimportant. No evidence for a tetramethylene biradical intermediate was found. The reaction mechanism probably involves the simultaneous splitting of two opposite C—C bonds. / Science, Faculty of / Chemistry, Department of / Graduate

The transfer of energy from one species of hydrocarbon to another has been observed. The conditions under which such transfer occurs indicate that one aromatic hydrocarbon may be absorbed onto crystals of the other forming a surface complex with a binding energy of a few hundred calories. Transfer of energy occurs readily between the components of this complex but not between molecules of different hydrocarbons when both are in solution. However, evidence for resonance transfer of energy between pairs of molecules of the same substance when both are in solid solution has been found. Studies of a large number of hydrocarbons have failed to reveal any single electronic property of the molecule which determines its ability to form complexes of the type found. The techniques developed were applied to a preliminary study of the rate of disappearance of carcinogenic hydrocarbons applied to the skin of mice. Also included are literature surveys on the known interactions of polycyclic hydrocarbons, the mode of reaction of carcinogenic hydrocarbons with living cells, and the spectral properties of chlorophyll. / Science, Faculty of / Chemistry, Department of / Graduate

Technetium catalyzes hydrocarbon reforming reactions of dehydrocyclization, isomerization, hydrogenolysis, and coke formation. A kinetic equation was derived and E_a and A_o evaluated for dehydrocyclization of n-heptane, isomerization of n-pentane, and dehydrogenation of methylcyclohexane and cyclohexane. The results were related to the metal, the form of the catalyst, catalyst support, and the deactivation of the catalyst. The effect of sulfur compounds was determined. No residual radioactivity in the product was observed. The ligands, acetone azine (AA) and 3,5,5-trimethyl-2- pyrazoline (Py), reacted with (C_6H_5CN)_2PdCl_2 to form adducts, L_2PdCl_2 and (LPdCl_2)_n. Their structures were characterized by spectroscopic methods and some molecular weights determined. The basicity of the ligands, as well as acetone hydrazone (AH), was determined and found to be the same order as their ligand strength. AH rapidly reduces PdCl_2 to Pd. HPy+ and Py^_2PdCl_2 were studied for their rate of Py production from AA. Heats of reactions to form AA and AH were measured.

No description available.

No description available.

No description available.