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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.
101

The effect of light crude oil contamination on the geotechnical properties of kaolinite clay soil

Ota, Jonathan Okore January 2013 (has links)
Crude oil is of economic importance to any nation. However its poor management and disposal method has resulted in oil spillage and ground contamination. Most emphasis on crude oil contamination on the environment has been on surface and ground water pollution, as well as plants and animals with little or no attention paid to the engineering properties of the contaminated soil. This research is thus aimed at investigating the effect of light crude oil contamination on the geotechnical properties of kaolinite clay soil. This research is a laboratory based experiment in which the contaminated soil was prepared by adding different percentages of light crude oil (2%, 5%, 8%, 10%, 15% and 20%) measured by weight of the dry soil sample and mixed until a uniform mixture was obtained. The British Standard Test Methods for Civil Engineering purposes BS 1377: 1990 (EUROCODE 7: EN 1997: 2-5) was adopted with few modifications. The calculations were based on the fact that the pore space in the contaminated soil is occupied by water and crude oil so water content was calculated from the fluid content and the rate of evaporation of crude oil during oven drying was also considered. The classification results showed that crude oil contamination caused an increase in linear shrinkage, liquid limit, plastic limit and plasticity index between 0% to 20% contaminations. The compaction result showed that there was an increase in maximum dry density while the optimum moisture content decreased between 0% and 15% of crude oil contamination. The result showed that the soil could not compact at 20% contamination and above. Also, the coefficient of permeability increased with increase in the percentage of crude oil contamination while the coefficient of consolidation value (Cv) increases with increase in the percentage of contamination. There was a decrease in the cohesion value and the frictional angle due to the introduction of the crude oil into the soil. Although crude oil altered the geotechnical properties of the kaolinite clay soil and reduced its strength, the soil can still be used for geotechnical purposed after remediation.
102

Evaluation of crude fibre digestibility in Venda and Ross 308 broiler chickens

Sekgobela, Modjadji Mercy January 2018 (has links)
Thesis (M.Sc. (Animal Production)) --University of Limpopo, 2018. / Refer to the document
103

Investigation Of Productivity Of Heavy Oil Carbonate Reservoirs And Oil Shales Using Electrical Heating Methods

Hascakir, Berna 01 September 2008 (has links) (PDF)
The recovery characteristics of Bolu-Himmetoglu, Bolu-Hatildag, K&uuml / tahya- Seyit&ouml / mer, and Nigde-Ulukisla oil shale samples and Bati Raman, &Ccedil / amurlu, and Garzan crude oil samples were tested experimentally using retort and microwave heating techniques. Many parameters like heating time, porosity, water saturation were studied. To enhance the efficiency of the processes three different iron powders (i.e. / Fe, Fe2O3, and FeCl3) were added to the samples and the doses of the iron powders were optimized. While crude oil viscosities were measured to explain the fluid rheologies, since it is impossible to measure the shale oil viscosity at the laboratory conditions due to its very high viscosity, shale oil viscosities were obtained numerically by using the electrical heating option of a reservoir simulator (CMG, STARS 2007) by matching between the laboratory and numerical oil production and temperature distribution results. Then the field scale simulations for retorting of oil shale and crude oil fields were conducted. Since the microwave heating cannot be simulated by CMG, STARS, microwave heating was modeled analytically. In order to explain the feasibility of heating processes, an economic evaluation was carried out. The experimental, numerical, and analytical results show that field scale oil recovery from oil shales and heavy crude oils by electrical and electromagnetic heating could be economically viable. While microwave heating is advantageous from an operational point of view, retorting is advantageous if the technically feasibility of the study is considered.
104

Didžiųjų moliūgų (Cucurbita maxima D.) vaisių cheminės sudėties kitimas laikymo metu / The changes of pumpkins ( Cucurbita Maxima D.) fruits chemical composition during their storage

Juozaitytė, Viktorija 13 June 2014 (has links)
Magistrantūros studijų baigiamajame darbe pateikiami laikomų didžiųjų moliūgų minkštimo cheminės sudėties kitimo duomenys, koreliacijos ryšiai. Tyrimo objektas: laikomi didžiųjų moliūgų vaisiai. Tyrimo tikslas: nustatyti cheminių junginių kiekio kitimą didžiųjų moliūgų (Cucurbita maxima D.) vaisiuose laikymo metu. Uždaviniai: • Nustatyti didžiųjų moliūgų vaisių minkštimo cheminę sudėtį; • Įvertinti didžiųjų moliūgų cheminės sudėties kitimą laikymo metu; • Jusliškai įvertinti moliūgų vaisių minkštimo kokybę. Tyrimo metodai: Moliūgų vaisių derlius buvo laikomas patalpoje, kurioje aplinkos temperatūra - 14 oC, santykinis oro dėgnis 70 %. Tyrimo rezultatai: • Pirmoje darbo dalyje išnagrinėta moliūgų istorija, maistinė vertė, panaudojimo galimybės. • Antroje darbo dalyje aptariamas tyrimo objektas ir metodika. • Trečioje darbo dalyje pateikiami darbo rezultatai: pagal moliūgų minkštimo cheminę sudėtį, galime teigti, Didžiausias žalios ląstelienos (13,85 %) kiekis, askorbo rūgšties (7,73 mg 100g-1) ir karotenoidų (17,69 mg 100g-1) kiekis, nustatytas 'Amazonka' minkštime. Laikymo metu pastebėtas žalių pelenų kiekio didėjimas 'Karowita' ir 'Justynka' minkštime. Askorbo rūgšties, sausųjų medžiagų, karotenoidų, kalio ir nitratų kiekiai laikymo eigoje, visų tirtų moliūgų minkštime, mažėjo. Jusliškai įvertinus moliūgo minkštimą, galime teigti, pagal skonį, kvapą ir išvaizdą geriausias prieš ir po laikymo buvo 'Justynka' minkštimas. / Research object: great pumpkin fruit storage. Research aim: identify the chemical compounds in the evolution of great pumpkin (Cucurbita maxima D.) fruit during storage. Objectives: • Evaluation of chemical composition of great pumpkin fruit pulp; • Evaluation of great pumpkin chemical composition during their storage; • Pumpkin fruit pulp sesnsory analysis; Research methods: The pumpkin fruits were stored in 14 ºC temperature and 70% air Degn. Research results: o The first part will examine the history of the pumpkin, nutritional value, usability. o The second part deals with the study and methodology. o The third part of the work results: The 'Amazonka' had highest amount of crude fiber (13,85%), ascorbic acid (7,73 mg 100 g -1) and carotenoids (17,69 mg 100 g-1). During the storage raw ash amount increased in 'Karowita' and 'Justynka' varieties pumpkins pulps. Amounts of ascccorbic acid, dry matters, carotenoids, potasium and nitrate decreased during the storage. The best taste, odour and appearance had 'Justynka' pumpkin pulp.
105

Modeling Mild Thermal Cracking of Heavy Crude Oil and Bitumen with VLE Calculations

Guerra, André 20 August 2018 (has links)
The current shortage of crude oil from conventional sources has increased interest in developing unconventional resources such as oil sands. Heavy crudes and bitumen are found in Northern Alberta and their exploration, processing, and transport to market pose challenges in the use of these resources. Part of the solution to these challenges involves the reactive thermal processing of heavy crudes and bitumen. This thesis focused on mild thermal cracking reactions, and two studies regarding these reactions were presented. The first was an experimental study performed in a pilot-scale semi-batch reactor. The three crude oils were heated to 350, 400, 425, and 450°C at 1240 kPa. A five-lump reaction model combined with a process simulator with VLE calculations was fitted with the experimental data obtained. The goodness of fit between the model predicted values and experimental values for the Hardisty (MBL), Albian Heavy Synthetic (AHS), and Christina Lake Dilute Bitumen (CDB) were determined to be 0.99, 0.99, and 0.98, respectively. Moreover, 80, 85, and 89% of the optimized model’s predicted values had less than 10% error for MBL, AHS, and CDB, respectively. The second study described the implementation of a mild thermal cracking reaction model to the development of a train car fire-model for the assessment of safety aspects in the design of train cars used to transport crude oil. Case studies were conducted using the UniSim® depressuring utility and a previously developed mild thermal cracking reaction model to demonstrate the effect of compositional change. Three crude oils with varying properties and representative of the types of crudes transported by rail in Canada were used here: MBL, AHS, and CDB. The case studies conducted showed the performance of a train car fire-model to be dependent on the crude oil characteristics: up to -57% and -99% difference in model predicted variables for AHS and CDB, respectively, when compared to MBL. Furthermore, the model’s performance was also shown to be affected by the compositional change of a given crude oil due to mild thermal cracking reactions: up to 42% difference in model predicted variables when compared to the base case.
106

Avaliação da tensão interfacial entre petróleo parafínico e superfícies com resinas epóxi / EVALUATION INTERFACIAL TENSION BETWEEN PARAFFIN OIL AND SURFACES WITH EPOXY RESINS

Valença, Silvio Leonardo 26 February 2010 (has links)
Oil is a very complex chemical system, as for instance, the paraffinic type which was considered as a fluid to be evaluated in this scientific paper, trough the static interfacial tension with the surfaces of the API 5L grade B conduction pipe and the EPOXY and EPOXY M resins. The paraffinic oil produced in the 7-PIR-244D-AL well, which is located in the producing field of Pilar in the state of Alagoas, presents special characteristics concerning its flow which are different from the other oils in the Sedimentary Basin of Sergipe and Alagoas. The resin used in the experiments were the EPOXY, commercially know as DGEBA, as well as EPOXY M, which was produced from the DGEBA with the addition of a substance whose objective is to reduce the deposit of organic and/or inorganic molecules in its surfaces along the oil flow. The evaluation of the static interfacial tension between this type of paraffinic oil and the surfaces of the EPOXY (37,2 mN/m), EPOXY M (14,8 mN/m) resins and the steel pipe (4.790,2 mN/m) has produced results, the performance of this fluid compared with the EPOXY M resin was better than when compared with the EPOXY and, as a consequence, better than when compared with the metallic material of the pipe. As a result of the data got through the experiments with these materials, there was a conclusion about the possibility of practical use of the EPOXY M resin as a coating in the internal surface of the pipes that carry oil with a considerable quantity of paraffin in its composition, aiming at a better performance relating to the flow of this fluid. / O petróleo é um sistema químico bastante complexo, como por exemplo, o do tipo parafínico, o qual foi considerado como o fluido para ser avaliado nesse trabalho científico, através da tensão interfacial estática com as superfícies do tubo de condução metálico API 5L grau B e das resinas EPÓXI e EPÓXI M. O óleo parafínico produzido no poço 7-PIR-244D-AL, o qual está localizado no campo produtor de Pilar no estado de Alagoas, apresenta particularidades com relação ao escoamento, diferentes dos outros petróleos na Bacia Sedimentar de Sergipe e Alagoas. As resinas utilizadas nos experimentos foram a EPÓXI comercialmente denominada DGEBA, como também a EPÓXI M que foi produzida a partir da DEGEBA com a adição de uma substância cuja finalidade é reduzir o depósito de moléculas orgânicas e/ou inorgânicas nas suas superfícies durante o escoamento do petróleo. A avaliação da tensão interfacial estática entre este tipo de petróleo parafínico e as superfícies das resinas EPÓXI (37,2 mN/m) e EPÓXI M (14,8 mN/m) como também do tubo de aço (4.790,2 mN/m), gerou resultados; onde a performance desse fluido com relação a resina EPÓXI M foi melhor quando comparada com a EPÓXI, e conseqüentemente em relação ao material metálico do tubo. Como conseqüência dos dados obtidos através dos experimentos realizados entre estes materiais, concluiu-se a possibilidade de uso prático sobre a utilização da resina EPÓXI M como revestimento junto à superfície interna de tubulações que possuam petróleo com considerável quantidade de parafina em sua composição, objetivando um melhor desempenho quanto ao escoamento desse fluido.
107

Utilizing DDGS and crude glycerol in animal diets: feed manufacturing considerations

Mader, Erin F. January 1900 (has links)
Master of Science / Department of Grain Science and Industry / Leland McKinney / Three experiments were conducted to evaluate value added uses for dried distillers grains with solubles (DDGS) and crude glycerol in swine and poultry diets. In Exp.1, crude glycerol from multiple biodiesel production facilities was evaluated for storage and variability characteristics. Part one reviewed the storage capabilities of crude glycerol at room temperature and excessive heat conditions on ferrous and stainless steel metal. There was no notable corrosion during the two-month experiment for either metal type under each condition. There was a slight discoloration observed on the ferrous metal stored under excessive heat conditions, but no pitting or sign of corrosion was noted. No changes were observed in the stainless steel under either environment condition. Part two evaluated the variability of crude glycerol from multiple biodiesel production facilities. Representative samples of the parent feedstock and resultant glycerol was collected an analyzed. There was considerable variation between samples, particularly when comparing glycerol from the different feedstocks (vegetable vs. animal). Exp. 2 and 3 took place in the Feed Processing Research Center in the Department of Grain Science at Kansas State University. Pellet quality and electrical energy consumption was evaluated by reviewing production rate, conditioning and hot pellet temperatures, motor load, and pellet durability index (PDI) as testing parameters. In Exp. 2, diets containing varying levels of crude glycerol were evaluated on pellet quality and pellet mill performance in a pilot mill and in a commercial facility. For part one, a corn-soy based swine grower diet was formulated to contain 0, 3, 6, and 9% crude glycerol. Each diet was steam conditioned to 150, 170 and 190 °F in an atmospheric conditioner and pelleted. An interaction existed between glycerol and conditioning temperature. For all diets containing glycerol, roll skid occurred and the pellet mill plugged as conditioning temperature approached 190°F. Pellet quality increased linearly (P < 0.01) with increasing levels of glycerol. Part two took place at Don’s Farm Supply in Newell, IA. A corn-soy based turkey grower diet was formulated to contain 3% glycerol and pelleted. Results from part two were consistent with part one, in that there was an interaction between conditioning temperature and the addition of glycerol. Exp. 3 evaluated DDGS on pellet quality and electrical consumption. A poultry diet was formulated to contain 0, 15, or 30% DDGS and steam conditioned to 140, 160, and 180°F. As conditioning temperature increased, pellet quality in diets containing DDGS significantly improved (P>.001). Electrical consumption in diets containing DDGS compared to the control showed no significance in reduction in energy usage (P>.001). In conclusion, the production of pelleted diets containing crude glycerol is a feasible option; however, conditioning temperatures should be kept minimal and storage and variation of the material should be considered. In addition, improved pellet quality in pelleted diets containing DDGS is in part by conditioning at higher temperatures, respectively. The data suggests that the addition of crude glycerol and DDGS in animal diets can serve as a beneficial feed additive.
108

Investigations into the pre-treatment methods for the removal of nickel (II) and vanadium (IV) from crude oil

Ikyereve, Rose E. January 2014 (has links)
The efficacy of using zeolitic materials for the removal of nickel (II) and vanadium (IV) ions from solution has been evaluated in order to provide a method for the removal of the metal ions during hydroprocessing of crude oil. Batches of sodium based zeolites with a variety of pore sizes and Si/Al ratios were prepared using standard methods (high causticity solutions and templating agent). Characterisation of the products was carried out using powder X-ray diffraction, infrared spectroscopy, Raman spectroscopy and thermogravimetric analysis to confirm the presence of single zeolitic phases (zeolite A, zeolite X, zeolite Y, sodalite Na8 [AlSiO4]6Cl2 and hydrosodalite Na6 [AlSiO4]6. 6H2O). In a batch exchange process, divalent nickel and tetravalent vanadium ion solutions of concentration range 0.01M - 0.1M were placed in contact with the zeolite samples at 110°C for a period of 24h. Nickel (II) exchange was found to occur for all the zeolites at concentrations considered. Zeolite X was found to be most efficient at removing nickel from the solutions while zeolite Y was least efficient. Characterisation of zeolite X after ion exchange using powder X-ray diffraction and scanning electron microscopy showed that the structure of the zeolite had been maintained. Simplistic modelling of powder X-ray diffraction data have shown that the nickel ions are preferentially substituted on one of the four sodium sites. Vanadium (IV) exchange was also found to occur for all the zeolites at the concentrations considered. Zeolite A was found to be most efficient for the vanadium uptake. Characterisation with PXRD, FTIR and SEM-EDS however, shows that in addition to exchange at the zeolite s normal cation exchange sites, a significant amount of framework silicon species were also exchanged by the vanadium ions thus having a destructive effect on the zeolite framework leading to structural collapse. Ion exchange of the sodium-based zeolites with potassium and lithium showed that the uptake of nickel and vanadium of the zeolites significantly increased compared to the as- synthesised zeolites. Zeolite Y was surface-modified with the APTES ligand and showed a similar trend to that observed for alkali metal-zeolites; showing significantly greater nickel uptake at lower concentrations. Nickel-tetraphenylporphrin was synthesised as a mimic for the nickel-asphaltenes found in crude oil and an α-hydrogen donor solvent used to remove the nickel in the presence of zeolite ion exchangers. A similar trend was observed to that seen in aqueous solution, implying the process would be transferrable to a live medium. Analysis to determine the metal ions present in ashed Nigerian crude samples before and after solvent and/or complexing agent extraction was carried out using inductively coupled plasma mass spectroscopy (ICPMS) and energy fluorescence analysis by X-rays (XRF). The process showed varying amounts of nickel was extracted by the different media along with iron. For nickel, the extent of extraction in the order of increasing % extraction is H2O<H3PO4<EDTA<IPA. For iron the order of increasing % extraction was H2O=EDTA<H3PO4<CH3OH while zinc extraction was in the order H2O<H3PO4 <CH3OH=EDTA.
109

Environmental Drivers of Differences in Microbial Community Structure in Crude Oil Reservoirs across a Methanogenic Gradient

Shelton, Jenna L., Akob, Denise M., McIntosh, Jennifer C., Fierer, Noah, Spear, John R., Warwick, Peter D., McCray, John E. 28 September 2016 (has links)
Stimulating in situ microbial communities in oil reservoirs to produce natural gas is a potentially viable strategy for recovering additional fossil fuel resources following traditional recovery operations. Little is known about what geochemical parameters drive microbial population dynamics in biodegraded, methanogenic oil reservoirs. We investigated if microbial community structure was significantly impacted by the extent of crude oil biodegradation, extent of biogenic methane production, and formation water chemistry. Twenty-two oil production wells from north central Louisiana, USA, were sampled for analysis of microbial community structure and fluid geochemistry. Archaea were the dominant microbial community in the majority of the wells sampled. Methanogens, including hydrogenotrophic and methylotrophic organisms, were numerically dominant in every well, accounting for, on average, over 98% of the total Archaea present. The dominant Bacteria groups were Pseudomonas, Acinetobacter, Enterobacteriaceae, and Clostridiales, which have also been identified in other microbially-altered oil reservoirs. Comparing microbial community structure to fluid (gas, water, and oil) geochemistry revealed that the relative extent of biodegradation, salinity, and spatial location were the major drivers of microbial diversity. Archaeal relative abundance was independent of the extent of methanogenesis, but closely correlated to the extent of crude oil biodegradation; therefore, microbial community structure is likely not a good sole predictor of methanogenic activity, but may predict the extent of crude oil biodegradation. However, when the shallow, highly biodegraded, low salinity wells were excluded from the statistical analysis, no environmental parameters could explain the differences in microbial community structure. This suggests that the microbial community structure of the 5 shallow, up-dip wells was different than the 17 deeper, down-dip wells. Also, the 17 down-dip wells had statistically similar microbial communities despite significant changes in environmental parameters between oil fields. Together, this implies that no single microbial population is a reliable indicator of a reservoir's ability to degrade crude oil to methane, and that geochemistry may be a more important indicator for selecting a reservoir suitable for microbial enhancement of natural gas generation.
110

Ecological Remediation Using Bacterial, Fungal, and Plant Microcosms: An Effective Solution for Bunker C Crude Oil Contamination in Waterways

Schenker, Jakob E. 01 January 2014 (has links)
Factory legacy pollutants are an increasing concern for waterways as old infrastructure deteriorates and contaminates nearby environments. The Fisherville Mill in Grafton, Massachusetts, USA exemplifies this problem since it has now fallen into disrepair and is leaking Bunker C crude oil into the adjoining Blackstone River, a third order stream. Our research examines how effectively an ecologically engineered system (EES), consisting of anaerobic bacteria environments, fungal microcosms, and aquatic plant environments, can break down petroleum hydrocarbons, specifically aliphatic and polycyclic aromatic hydrocarbons (PAH), in this river environment. Our testing protocol involved taking water samples before and after each filtration stage monthly from June through October 2012. Water samples were analyzed at the Brown University Superfund Research Lab using mass spectrometry to determine aliphatic and PAH concentrations. Post-treatment aliphatic oil concentrations were significantly different from baseline concentrations (p=0.005), with an average reduction of 95.2%. Post-treatment PAH concentrations were also significantly different from baseline concentrations (p=0.001), with an average reduction of 91%. We conclude that this EES provided effective treatment for Bunker C crude oil, even though some filtration stages did not achieve their intended objectives. This type of filtration arrangement might be scaled up for use in larger remediation efforts regarding Bunker C crude oil.

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