This research was conducted in order to enable primary producers to maximize the use of cheap roughage sources while still maintaining body weight during dry winter months when the crude protein (CP) content of roughage sources are at a minimum. The data obtained from this study will give an economic advantage when formulating supplements to be used during this time of the year. The aim of this study was to determine the optimum level of non-protein-nitrogen (NPN) and fermentable metabolizable energy (FME) to increase microbial protein synthesis, optimize rumen fermentation and increase digestibility of dry matter (DM) and neutral detergent fibre (NDF) in sheep fed on poor quality forages. A metabolic trial was conducted where intake of DM, organic matter (OM), NDF and CP was recorded; rumen volatile fatty acid (VFA) production was recorded as well as rumen pH over the different treatments. Microbial protein synthesis was determined by analysing purine derivatives in the urine. An in situ trial was also done to determine changes in ruminal digestibility of DM and NDF on different treatments. Five treatments were used. Treatment 1 consisted of NPN and FME balanced according to the NRC (2007) requirements for a 50kg whether, and served as a control. Treatment. Treatment 2 consisted 15% less NPN than control but the same amount of FME than control while treatment 3 consisted 15% more NPN than the control but the same amount of FME as the control treatment. Treatment 4 consisted of 15% less FME, but the same amount of NPN, than the control treatment, while treatment 5 consisted of 15% more FME, but the same amount of NPN than the control treatment. A 5 x 5 Latin square design was used in this study. Five Merino wethers were allowed to adapt to supplements which were infused directly into the rumen at 9:00 and 15:30 every day. After adaptation animals were placed in individual metabolic crates for three and given three day to adapt to crate environment. After the initial three days the sampling period commenced. Results obtained indicated that treatment had no effect on DM, OM, NDF and water intake but intake of CP was significantly increased for treatment 3 when compared to treatment 2. When intake of DM, OM, NDF and CP, related to metabolic bodyweight (W0.75) was calculated, treatment 5 resulted in lower intake of both water and NDF as compared to treatment 4. Differences between levels of FME and NPN in this study was insufficient to have an influence on DMD, OMD or NDFD however, CP degradability was increased for treatment 3 and treatment 5. Ruminal pH was unaffected by treatment. Increased levels of NH3-N for treatment 3 when compared to treatment 1 and 2, was observed. Both treatments 2 and 5 resulted significant decreases in rumen NH3-N. Treatments had no effect on the proportions of VFA produced or on the Acetate to Propionate produced ratio. Treatment 3 caused an improvement in CP an N balance when compared to treatment 1 and 2. Treatment 3, when compared to treatment 1 and 2, lead to an increase in N balance/kgW0.75. Treatment 5 caused a higher microbial protein synthesis in contrast to treatment 4. Results from the in situ trial showed a decreased a-value (solubility) for the NDF fraction of treatment 3 when compared to treatment 2. The rate of degradability (c) of both DM and NDF was increased for treatment 2 compared with treatment 3. The b, ED and PD values showed no response to treatment. / Dissertation (MSc Agric)--University of Pretoria, 2013. / gm2014 / Animal and Wildlife Sciences / unrestricted

A set of crude oil samples with different composition and characteristics is studied by means of Fast Field Cycling (FFC) 1H relaxometry, which probes the distribution of longitudinal relaxation times T1 as a function of the Larmor frequency. Investigation of T1 profiles at different temperatures is able to provide an insight into the dynamics and structural changes of oil components, with our particular interest being the high temperature behaviour of asphaltene. It is well-known that asphaltenes tend to form porous clusters in crude oils, which can cause severe problems for the process of oil extraction. Therefore, FFC experiments are conducted on Stelar Spinmaster FFC2000 in the temperature range 203K < T <443K, where the upper limit of 443K is aimed at approximating the typical maximal in-situ well temperatures. FFC relaxometry data of crude oils at such a high temperature are obtained for the first time with the use of a specially modified NMR probe. Inverse Laplace transformation is applied to the longitudinal agnetization decays, yielding T1 distributions at different frequencies. A comparative analysis of these distributions for different Larmor frequencies and temperatures showed that there is a systematic variation of the frequency dependence of T1 correlating with the asphaltene content in the samples, at temperatures similar to the well conditions.

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<p>This dissertation presents several examples of diverse applications of mass spectrometry. For example, high-resolution mass spectrometry was utilized for qualitative and quantitative chemical characterization of ionized compounds in petrochemical samples, specifically, in condensate-like oil samples. Further, the ability to use tandem mass spectrometry to rapidly detect trace amounts of short-lived reaction intermediates in solution reactions is demonstrated. Finally, selective tandem mass spectrometry methods based on diagnostic gas-phase ion-molecule reactions were developed for the identification of carboxylic acid functionalities in protonated analytes.</p>

This study demonstrated the presence of hyperthermophilic organisms in the upper Jurassic Smackover formation in Womack Hills, AL. Evidence for the presence of these organisms was shown by the cultivation of an aerobic and an anaerobic, oil-degrading hyperthermophilic culture from the cuttings of an oil well in the Jurassic Smackover at 90¢ªC. Viability of microorganisms in the formation was established through electron microscopy, by carbon dioxide production, and by protein production during incubation in medium at 90¢ªC. Not only was the presence of viable microorganisms in the reservoir established, but as a result of this study, new cultivation methods were also developed that may prove useful in future studies of these types of organisms.

This thesis evaluates the possibility to use a iron-based catalyst as a pyrolysis vapour conversion catalyst. The iron catalyst was also compared with the mineral dolomite. The experiments were facilitated at Cortus Energy's demonstration plant in Koping, Sweden, by in situ instal- lation of the experimental setup to an outlet of the pyrolyser unit. The pyrolysis vapour from Cortus Energy was converted for a total of 8 hours by passing it through a packed bed reactor containing the iron-based catalyst while sampling gas and oil from the feed for analysis. The outset for the operation on the dolomite catalyst bed was the same as for the iron catalyst with a resulting collapse of the bed when the pyrolysis vapour was introduced. The permanent gases were analysed on site with a µ-GC unit while oil samples were condensed and analysed with GC-MS, H-NMR and Karl Ficher titration. The carbon laydown and surface area of the catalyst was determined as well as the phase changes of the catalyst surface with XRD. The results showed clear indications of bio-crude conversion with an eightfold increase of the H2 concentration of the synthetic gas from 3.38 % to 26.69 % on a dry gas basis. The oxygen to carbon (O:C) ratio decreased in the treated pyrolysis oil compared to the untreated oil while the hydrogen to carbon (H:C) ratio showed indications of dehydration of the oil. The gas and water content of the stream increased while 57.2 % of the oil was converted in the process. Lastly, the iron-based catalyst did not seem to favour the conversion of alkylated phenols.

This work presents a techno-economic analysis of multiple direct hydrogen production technologies using different blends of Arabian crude oil and natural gas as feedstock: Auto thermal reforming, steam reforming, and combined reforming technologies are thermodynamically and technically evaluated through development of process flowsheets. Comparative analysis indicates that combined reforming using Arabian light crude oil achieves a 22.69 % of hydrogen recovery with carbon capture, which is higher than auto thermal reforming and steam reforming by 0.7 %. At the same time, auto thermal reforming achieves a 26.70 % of hydrogen recovery without carbon capture, which is higher than steam reforming and combined reforming by 4 %. Arabian heavy, medium, light, and extra light are evaluated using auto thermal reforming technology to estimate hydrogen recovery values. A wide range of crude oil and natural gas prices are included in the analysis to calculate hydrogen production cost. With crude oil price at 90 USD/bb, the hydrogen production cost is 2.9 USD/kg, and natural gas prices at 30 USD/MMBtu (Europe), 20 USD/MMBtu (Japan), and 2.5 USD/MMBtu (GCC region), the hydrogen production cost is 4.5, 3.0, and 0.4 USD/kg respectively.

Planning, scheduling and real time optimization (RTO) are currently implemented by using different types of models, which causes discrepancies between their results. This work presents a single model of a crude distillation unit (preflash, atmospheric, and vacuum towers) suitable for all of these applications, thereby eliminating discrepancies between models used in these decision processes. Hybrid model consists of volumetric and energy balances and partial least squares model for predicting product properties. Product TBP curves are predicted from feed TBP curve, operating conditions (flows, pumparound heat duties, furnace coil outlet temperatures). Simulated plant data and model testing have been based on a rigorous distillation model, with 0.5% RMSE over a wide range of conditions. Unlike previous works, we do not assume that (i) midpoint of a product TBP curve lies on the crude distillation curve, and (ii) midpoint between the back-end and front-end of the adjacent products lies on the crude distillation curves, since these assumptions do not hold in practice. Associated properties (e.g. gravity, sulfur) are computed for each product based on its distillation curve. Model structure makes it particularly amenable for development from plant data. High model accuracy and its linearity make it suitable for optimization of production plans or schedules. / Thesis / Master of Applied Science (MASc)

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental toxicants found in anthropogenic mixtures such as crude oil, air pollution, vehicle exhaust, and in some natural combustion reactions. Single PAHs such as benzo[a]pyrene (BaP) also impact fish behavior when animals are exposed in early life stages and for short periods of time. Aquatic animals such as fish may encounter BaP through road runoff and oil spills, but few studies have examined the impact of aqueous exposure on adult fish, and fewer have examined the resulting fitness-relevant behavioral consequences of BaP and PAH mixtures and their long-term persistence. This dissertation targets this gap in the literature by examining how aqueous exposure to BaP influences anxiety-like behavior, learning, and memory in adult zebrafish, and how parental exposure to the PAH mixture, crude oil, combined with hypoxia affects social and exploratory behavior in unexposed larval zebrafish. We found that learning and memory were not affected by 24 hour exposure to BaP, that anxiety-like behavior was minimally affected, and that locomotor parameters such as distance moved and times spent in darting and immobile states were significantly altered by exposure to BaP. Additionally, we found that parental exposure to crude oil and hypoxia decreased larval velocity. Additionally, we examined how crude oil, BaP, and the detergent COREXIT influence a monolayer of mouse and fish endothelial cells, as an in vitro blood-brain barrier (BBB) model. We found that exposure to BaP in particular caused significant damage to both fish and mammal in vitro BBB models, and damage to the BBB is one potential mechanism by which neural integrity and behavior may be influenced. Understanding how these toxicants influence fish brains and behavior will give insight into how fish populations explore and interact with their environment and with predators, and how these interactions persist even when toxicants are no longer present.

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