Thesis (Ph. D.)--Missouri University of Science and Technology, 2009. / Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed August 10, 2009) Includes bibliographical references.

The importance of organic sulphur fixation in the preservation of organic matter in humic coal-forming environments is demonstrated in this thesis. The transgression of coal depositional systems by marine waters during their deposition and early diagenesis enables the production of reduced inorganic sulphur species by sulphate-reducing bacteria. The presence of these reactive sulphur species, in combination with the altered chemical and microbial regime, influences the preservation and petroleum potential of humic coal.Three lignite samples taken over a two meter depth profile of a core in the Eocene, Heartbreak Ridge lignite deposit, SE Western Australia, were analysed by a suite of geochemical techniques to identify origins and transformation pathways of their organic matter. Rock-Eval, FTIR microscopy, and pyrolysis gas chromatography-mass spectrometry (Py-GCMS) indicate that the composition of the lignite and its extract are typical of immature type III organic matter with a predominance of aromatic and oxygen containing functionalities. Variation in the macromolecular composition of the three lignites are consistent with more pronounced degradation of the organic matter in the lowermost lignite horizon. Nickel boride desulphurisation of polar and asphaltene fractions of the lignites showed the presence of sulphur-bound higher plant triterpenoids, in particular olean-12-ene, n-alkanes of even predominance, C29 steranes and extended 17â(H),21â(H)-hopanes. Deuterium labelling experiments indicated that these components were mostly bound to a single sulphur, at sites about the original functionality in the natural product precursors. The presence of singularly sulphur-bound aromatic ring A degraded and pentacyclic triterpenoids represent the spectrum of aromatic triterpenoid intermediates undergoing diagenesis before sulphur incorporation.Stable carbon isotopic ++ / analyses of the free and sulphur-bound aliphatic hydrocarbons confirmed carbon sources from both higher plants and bacteria. Oxygenated lipids consisted of even carbon-numbered n-alkanoic monocarboxylic acids, ù-hydroxy fatty acids and n-alkanols, n-alkan-2-ones, 6,10,14-triinethylpentadecan-2-one, and oxygenated hopanoids and higher plant triterpenoids. BY the onset of sulphurisation in the Heartbreak Ridge lignite, extended hopanoid degradation had come to a hiatus, in marked contrast to the variable alteration of the higher plant triterpenoids. The oxygen-containing lipids of the extracts are implicated as the primary source of the sulphurised hydrocarbons, although not necessarily via direct sulphurisation of their present sent form, but through the formation of more reactive intermediates. These results implicate sulphur fixation as a means by which lipids of similar structures to the natural product precursors are preserved in coal forming environments. That diagenetic alteration of the oxygenated lipids mirrors that of the sulphur-bound hydrocarbons confirms that the onset of marine incursion and the formation of reduced inorganic sulphides does inhibit (and also preserve) the normal biogeochemical transformations of organic matter in coal-forming environments.The technique of reaction gas chromatography-mass spectrometry (R-GCMS) was also applied to the analysis of the polar extracts from a Heartbreak Ridge lignite, together with the polar extracts from the Monterey Formation shale (Naples Beach, USA; Miocene age). Palladium black acting as a catalyst under hydrogen carrier gas in the vaporising injection port of a GCMS, effected gas phase reaction of the volatile constituents in the polar mixtures.The fully active catalyst effected hydrogenation, desulphurisation and decarbonylation/decarboxylation reactions. Polar fractions of the Heartbreak Ridge lignite ++ / reacted to produce angiosperm-derived triterpenoids and bacterially-derived hopanoids. The reaction of the Monterey Formation shale polars resulted in the formation of high relative amounts of pristane and phytane with a predominance of the latter, as well. as a suite of steroidal and triterpenoid moieties, typical of marine organic matter. However, R-GCMS provided less detailed information on the exact nature of the functionalised lipids partitioned within the polar fraction than that obtained by more conventional wet chemical analyses.The compositions of 35 marine-influenced, bituminous coals, from the Eocene Brunner Coal Measures of New Zealand were studied to assess the effect of the timing of marine incursion on the molecular characteristics of coals. Based upon their stratigraphic position and their volatile matter and total sulphur contents, coal samples were classified into those where the mire was flooded during or at the end of deposition (Class A/B) and those that experienced postdepositional access of marine water during later diagenetic stages (Class C/D). Rock-Eval pyrolyses showed that sulphur-rich Brunner coals generally display moderate increases in pyrolytic yields with respect to the low-sulphur Brunner coals. Class A-C coals generally release larger quantities of hydrocarbons during Rock-Eval pyrolysis than the Class D coals, suggesting that sulphur fixation can enhance the hydrocarbon potential of buried mires, provided sulphur is introduced early. Variation in Carbon Preference Indices, isoprenoid/alkane ratios, the Methylphenanthrene Index and phenanthrene/anthracene of bitumens and pyrolysates both within different seam profiles and between different sampling localities can be attributed to changes in microbial regime as well as subtle variations in rank.Pristane/phytane, dibenzothiophene/phenanthrene and thiophene ratios are closely related ++ / to organic sulphur contents, but are also influenced by these changes in rank and differences in the timing of marine incursion.Organic sulphur contents and biomarker compositions are related through a drillcore profile, which confirms the role of diagenetic sulphur sequestration in preserving specific biomarkers (steranes, higher plant triterpanes, extended hopanes) in coal-forming environments. Biomarker ratios that vary accordingly include the homohopane index, Ts/Tm, C29Ts/norhopane, C30 diahopane/hopane, sterane/hopane ratio, C29 diasterane/sterane, oleanane/hopane, oleanoid triterpane/hopane, and ring A degraded triterpanes/des-E-hopane.Diasterane concentrations were greatest in high sulphur coals. It is suggested that sterenes, generated from sulphur-bound steroids of regular stereochemistry in the subsurface, undergo acid-catalysed rearrangement and hydrogenation to enhance diasterane concentrations. A similar formation mechanism can be invoked for the rearranged hopanes (Ts, C29Ts, C30 diahopane) and oleanoid triterpanes. The timing of sulphur fixation does not appear to have influenced the formation of biomarkers except in one case. The only lipid class that degraded rapidly enough for the precursors required for sulphurisation to be removed prior to saline access is the higher plant triterpenoids. Stable carbon isotopic analysis of the n-alkanes, isoprenoids and hopanoids from the Pike River Outcrop seam section confirms both higher plant and microbial sources. In particular, the carbon isotopic composition of phytane suggests that methanogenic decomposition of the Pike River peat occurred. The isotopic signatures are invariant to changes in the degree or timing (Class A-C only) of sulphur access to this outcrop.This body of work finds that the introduction of marine waters (and the formation of reduced sulphides) in the early stages of mire and peat ++ / development preserves the inherited lipid composition of the peat and does not overwhelm this biotic signature during sulphate reduction. As such, the selective preservation of certain biomarkers enables their use as indicators of marine-influence in source rocks. The application of several biomarker ratios to the characterisation of crude oils from the Taranaki Basin of New Zealand provides further evidence for the generation of liquid hydrocarbons from marine-influenced, angiosperm-rich coals.

Thesis (Ph. D.)--University of Rhode Island, 2006. / Typescript. Includes bibliographical references (leaves 126-134).

Thesis (M.S.)--Ohio University, November, 2004. / Title from PDF t.p. Includes bibliographical references (leaves 74-83).

No description available.

Corrosion is a serious industrial concern. According to a cost of corrosion study released in 2002, the direct cost of corrosion is approximately $276 billion dollars in the United States approximately 3.1% of their Gross Domestic Product. Key influences on the severity of corrosion include: metal and electrolyte composition, temperature, turbulent flow, and location of attack. In this work, mechanistic models of localized and flow influenced corrosion were constructed and these influences on corrosion were simulated.<p>A rigourous description of mass transport is paramount for accurate corrosion modelling. A new moderately dilute mass transport model was developed. A customized hybrid differencing scheme was used to discretize the model. The scheme calculated an appropriate upwind parameter based upon the Peclet number. Charge density effects were modelled using an algebraic charge density correction. Activity coefficients were calculated using Pitzers equations. This transport model was computationally efficient and yielded accurate simulation results relative to experimental data. Use of the hybrid differencing scheme with the mass transport equation resulted in simulation results which were up to 87% more accurate (relative to experimental data) than other conventional differencing schemes. In addition, when the charge density correction was used during the solution of the electromigration-diffusion equation, rather than solving the charge density term separately, a sixfold increase in the simulation time to real time was seen (for equal time steps in both simulation strategies). Furthermore, the charge density correction is algebraic, and thus, can be applied at larger time steps that would cause the solution of the charge density term to not converge.<p>The validated mass transport model was then applied to simulate crevice corrosion initiation of passive alloys. The cathodic reactions assumed to occur were crevice-external oxygen reduction and crevice-internal hydrogen ion reduction. Dissolution of each metal in the alloy occurred at anodic sites. The predicted transient and spatial pH profile for type 304 stainless steel was in good agreement with the independent experimental data of others. Furthermore, the pH predictions of the new model for 304 stainless steel more closely matched experimental results than previous models.<p>The mass transport model was also applied to model flow influenced CO2 corrosion. The CO2 corrosion model accounted for iron dissolution, H+, H2CO3, and water reduction, and FeCO3 film formation. The model accurately predicted experimental transient corrosion rate data.<p>Finally, a comprehensive model of crevice corrosion under the influence of flow was developed. The mass transport model was modified to account for convection. Electrode potential and current density in solution was calculated using a rigourous electrode-coupling algorithm. It was predicted that as the crevice gap to depth ratio increased, the extent of fluid penetration also increased, thereby causing crevice washout. However, for crevices with small crevice gaps, external flow increased the cathodic limiting current while fluid penetration did not occur, thereby increasing the propensity for crevice corrosion.

Corrosion is a serious industrial concern. According to a cost of corrosion study released in 2002, the direct cost of corrosion is approximately $276 billion dollars in the United States approximately 3.1% of their Gross Domestic Product. Key influences on the severity of corrosion include: metal and electrolyte composition, temperature, turbulent flow, and location of attack. In this work, mechanistic models of localized and flow influenced corrosion were constructed and these influences on corrosion were simulated.<p>A rigourous description of mass transport is paramount for accurate corrosion modelling. A new moderately dilute mass transport model was developed. A customized hybrid differencing scheme was used to discretize the model. The scheme calculated an appropriate upwind parameter based upon the Peclet number. Charge density effects were modelled using an algebraic charge density correction. Activity coefficients were calculated using Pitzers equations. This transport model was computationally efficient and yielded accurate simulation results relative to experimental data. Use of the hybrid differencing scheme with the mass transport equation resulted in simulation results which were up to 87% more accurate (relative to experimental data) than other conventional differencing schemes. In addition, when the charge density correction was used during the solution of the electromigration-diffusion equation, rather than solving the charge density term separately, a sixfold increase in the simulation time to real time was seen (for equal time steps in both simulation strategies). Furthermore, the charge density correction is algebraic, and thus, can be applied at larger time steps that would cause the solution of the charge density term to not converge.<p>The validated mass transport model was then applied to simulate crevice corrosion initiation of passive alloys. The cathodic reactions assumed to occur were crevice-external oxygen reduction and crevice-internal hydrogen ion reduction. Dissolution of each metal in the alloy occurred at anodic sites. The predicted transient and spatial pH profile for type 304 stainless steel was in good agreement with the independent experimental data of others. Furthermore, the pH predictions of the new model for 304 stainless steel more closely matched experimental results than previous models.<p>The mass transport model was also applied to model flow influenced CO2 corrosion. The CO2 corrosion model accounted for iron dissolution, H+, H2CO3, and water reduction, and FeCO3 film formation. The model accurately predicted experimental transient corrosion rate data.<p>Finally, a comprehensive model of crevice corrosion under the influence of flow was developed. The mass transport model was modified to account for convection. Electrode potential and current density in solution was calculated using a rigourous electrode-coupling algorithm. It was predicted that as the crevice gap to depth ratio increased, the extent of fluid penetration also increased, thereby causing crevice washout. However, for crevices with small crevice gaps, external flow increased the cathodic limiting current while fluid penetration did not occur, thereby increasing the propensity for crevice corrosion.

No description available.

Mine influenced waters (MIW) pose a broad range of potential environmental impacts, which often also carry financial and social consequences. MIWs are often high in solids content, and can have highly acidic or alkaline pH and high contents of metals or other problematic constituents (e.g., traces of chemicals used in minerals processing or water treatment). Acid mine drainage (AMD) is a common type of MIW characterized by low pH. Release of untreated MIWs like AMD to surface waters, for example, can lead to problems such as a sedimentation and siltation, undesirable changes in pH and/or precipitation of metals and salts, and addition of particular stressors for various aquatic organisms. As such, these waters are frequently captured and treated on-site in systems requiring extensive piping. Polyethylene (PE) pipes are popular in mining, including MIW, applications because they are chemically inert, and have relatively low costs, low density, and high flexibility. However, PE material is susceptible to abrasion. To combat this problem and offer a single pipe option for a variety of mining applications, Gerodur MPM Kunststoffverarbeitung GmbH and Co. KG.(Gerodur) has developed a novel liner for PE pipes. The liner is made of a rubber-like material that is resistant to mechanical abrasion by slurries or high-solids waters, but its susceptibility to mineral scale buildup has not been specifically evaluated. In order to evaluate scale buildup on the lined PE versus traditional PE pipe material, two studies were undertaken and are reported in this thesis. A short-term field study was conducted in the Reiche Zeche underground mine in Freiberg, Germany – an inactive lead-zinc mine. Water quality varies considerably between different zones in this mine, but is characterized by very high dissolved solids, which is typical for AMD. For this study, the pipe materials were exposed to waters in six locations for three weeks; and were then analyzed for weight gain and scale composition. Results showed that there was only a marginal difference in the scale build up when comparing the two piping materials. In a follow-up study in the laboratory, the two pipe materials were exposed over a total of 16 weeks to three idealized AMD water qualities: an untreated AMD made to simulate the most extreme condition observed in the field study, the same AMD following passive treatment (i.e., neutral pH), and the same AMD following active treatment (i.e., slightly basic pH). Exposure was done in pipe-loop apparatuses such that samples could be subjected to different flow and sedimentation conditions (i.e., gentle mixing only on the sides of the water reservoir, gentle mixing and sedimentation on the bottom of the reservoir, and constant flow and possible sedimentation within the pipe-loop tubing itself). Results of this study indicated that factors such as water chemistry and flow velocity had significant effect on the quantity and chemistry of scale. However, there was very little difference in propensity for scale build up between the two materials. This liner was designed in an effort to resist mechanical abrasion. Because scale build up is not exacerbated by the liner, it may provide a means for uniform applications across mines with contiguous abrasive and scale prone waters. That is, it could eliminate the need to have various specialized piping materials on a site to handle these problems individually, streamlining the pumping and piping network installation and operation. / Master of Science

<p>This essay will investigate the cause of <em>shifts – changes made when translating – in the Swedish version of Enid Blyton‟s <em>Five on a Treasure Island. It should be seen as a direct sequel to <em>The Little Girl is Missing – a bachelor degree project written at Stockholm University. In said degree project the methods used when making the shifts was described, but now the reasons <em>why the shifts were made and <em>how they have affected the plot will be presented. To do so a number of theories concerning both gender studies and translation studies will be used. </em></em></em></em></em></p><p>The working hypothesis is that the shifts were made to rid the translated text of the original text‟s sexist content – to create "equality between women and men" (Lpo 94: 3) and making the translation fit the target culture i.e. today‟s Sweden. This claimed sexist content will be determined mainly with the help of the Swedish compulsory school system‟s curriculum, Lpo94, and Berit Ås‟s master suppression techniques. The intention is to bring the translation phenomenon of ideologically influenced translations into the limelight and start a debate. Besides that, this essay will also provide a didactic model for teachers wanting to work with translation dilemmas in class.</p>