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1
Lei, Guowen. "Producing Gas-Oil Ratio Performance of Conventional and Unconventional Reservoirs." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for petroleumsteknologi og anvendt geofysikk, 2012. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-19514.
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This study presents a detailed analysis of producing gas-oil ratio performance characteristics from conventional reservoir to unconventional reservoir. Numerical simulations of various reservoir fluid systems are included for comparison. In a wide sense of the word, the term of unconventional reservoir is including tight gas sand, coal bed methane, gas hydrate deposits, heavy oil gas shale and etc. In this study we specify the unconventional reservoir to only mean the low and ultra low permeability reservoir, which is including tight or shale reservoir. As an emerging research topic in the E&P industry, shale reservoir’s long-term well performance characteristics are generally not well understood (Anderson et al. 2010). Research methods and techniques for conventional reservoir are usually directly used in this unconventional reservoir analysis. These methods, however, have proven to be too pessimistic (Anderson et al., 2010). Fit-for-purpose approaches or solutions should be introduced in this new topic. Recently, hydraulic fracturing treatment is commonly used in the low matrix permeability reservoir to attain an economic production rate. The difference of well production performance between conventional reservoir and unconventional reservoir is not well known. In this study, we are trying to give a quantitative analysis in order to answer this question.In this study, a “generic” reservoir from field data with constant reserves and size were assumed. This reservoir model is homogeneous and of constant porosity, permeability and initial water saturation. In order to compare the production performance, fluid systems are varied from volatile oil to near critical oil, to gas condensate and to wet gas. The permeability of the reservoir model is also designed from high (conventional reservoir) to ultra low (unconventional), which ranges from 101 to 10-5 mD. Influence from fracture is especially considered because fractures in the low permeability reservoir provide a high conductivity that connects the reservoir matrix to the horizontal well. Fractures in the model are designed with identical geometrical characteristics (length, thickness) and of inner homogeneous properties (porosity, permeability).A black-oil model is used for each reservoir, and its PVT properties are generated with a 31 components EOS model using Whitson-Torp procedure (Whitson et al., 1983). Reservoir fluid systems equilibrium calculation in the black-oil model is done using the initial gas-oil ratio. We have compared the well’s production performance for each fluid system.Based on the industry experience, two standards are used in reservoir simulation control: gas production rate and cumulative revenue. The gas production rate with 10 ×106 ft3/day in the first 10 days or the cumulative revenue equal to 5 ×105 USD from the first 10 days is set as the standard for the commercial well rate. All of these simulations are run under the control of these two types which have just been mentioned. A case of liquid rich gas reservoir is analyzed systematically, to compare its production performance when reservoir permeability is changed from high to low. We are interested in how much oil or gas condensate can be extracted from the “reservoir” if same initial fluids in the reservoir but of a different permeability. This study is useful and practical, particularly for the industry in the era of “high” oil price and “low” gas price in North America.The simulation results show that we can extract more liquid from the reservoir if the matrix permeability is higher, particularly for the reservoir with initially large oil contents (volatile oil reservoir, near critical reservoir and gas condensate reservoir). Fracturing treatment in unconventional reservoir is required to attain an economic production rate. We also realize that for the required number of fractures and reservoir’s matrix permeability, there exists linear correlation in log-log plot in the low-permeability reservoir. In this study, the unique optimization software Pipe-It and reservoir simulator SENSOR are used. Optimal simulation results of permeability combination are obtained by the module Optimizer in Pipe-It.
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Egejuru, P. C. "Low oil-water ratio invert emulsion mud for unconventional shale reservoirs." Thesis, University of Salford, 2017. http://usir.salford.ac.uk/43914/.
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Due to stringent environmental regulations on the disposal and management of the traditional diesel oil-based mud used for drilling difficult formations such as shale, there is the necessity to develop an environmentally friendly drilling mud. Vegetable oils such as Jatropha have proven to be a comparable alternative to diesel oil. However, there have been concerns of compatibility of the vegetable oils with the chemical additives and the ability to achieve a low oil-water ratio mud, which is beneficial to low fluid loss for enhanced wellbore stability. The focus of this study is to achieve a novel low oil-water ratio invert emulsion using Jatropha oil and egg yolk as an emulsifier. Shale-fluid interaction and the economic viability of the mud were also evaluated. The findings from this study show that the low oil-water ratio invert emulsion is beneficial to reducing fluid loss for enhanced wellbore stability and the reduction of oil retention on cuttings, thereby reducing cost of disposal and environmental impact. The mud was formulated without a fluid loss additive, wetting agent, secondary emulsifier and the need for high water content, thereby savings could also be made in material costs. The results from this experimental study demonstrated that the electrical stability of the mud emulsified by egg yolk at a test temperature of 48.9 and 120˚C for any variation, were 398 and 289V respectively. Comparatively, the mud emulsified with a standard emulsifier <I>versacleanVB</I> gave stability values of 201 and 188V thus indicating higher stability with the egg yolk. Moreover, the 50/50 oil-water ratio mud gave stability values of 353 and 258V hence, giving plastic viscosity of 36 cP, at the yield point of 17 Ib/100 ft<sup>2</sup> and 30 minutes fluid loss of 6ml with filter cake of 1.7 mm. This resulted to 50% reduction in fluid loss over the conventional 70/30 oil-water ratio mud, which was emulsified with the standard emulsifier with stability values of 480 and 393V, plastic viscosity of 31cP, yield point of 17 Ib/100 ft<sup>2</sup> and fluid loss of 12 ml with filter cake of 3.2 mm. Using the X-Ray Computed Tomography (CT) Scanner, the shale-fluid interaction also showed a volume increase by 11 and 23% of the core sample when immersed into water based mud from one to 7 days respectively. The result indicates that a high interaction with the fluid are possible, thus leading to a non-stable condition compared to 0.88 and 2.53% obtained from diesel and jatropha oil based muds. There was negligible variation in the structure of the samples exposed to diesel and jatropha oil based muds, which further suggests the suitability of jatropha as diesel substitute. The economic analysis of 50/50 oil-water ratio invert emulsion equally showed a potential saving of 57.91% of the $65.31 of the cost of formulation and 47.5% of $60 of the cost of disposal of the conventional diesel oil-based mud. This has the potential to equate to saving of $37.82 per barrel of invert emulsion formulated and $28.50 per barrel disposed.
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Alshuqaiq, Mohammad Abdullah. "An Analysis of Oil Combustion on Snow." Digital WPI, 2014. https://digitalcommons.wpi.edu/etd-theses/789.
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Several Arctic council reports conclude that oil spills are the most significant threat to the Arctic ecosystem. Some studies have shown that in-situ burning (ISB) of oil spills over water can remove more than 90% of the oil, and is the most promising technology for an efficient response to oil spills in the Arctic region. The definition of "In situ" is intentional, controlled burning of oil in place (i.e., without extracting or removing the oil first). Earlier studies [Bellino (WPI 2012), Farahani, (WPI 2014)] have investigated burning behavior of crude oil on ice, similar to what one would expect in sea-ice or bare lake ice conditions. The focus of the current study is to investigate the burning behavior of crude oil in snow, similar to oil spills in snow-covered land, or in snow covered sea ice in the Arctic. Understandably, due to the difference in packing density between ice/water and snow, the parameters that influence burning behavior of oil in snow are different compared to burning oil in the sea or ice conditions. The current experimental study shows that the snow behaves as a porous medium, and depending on the porosity and volume of the oil spill, two extreme behaviors are exhibited. In the case of an oil spill on snow with low porosity, the oil sinks easily to the bottom, and the burning involves, significant thermo capillary effects enabling the oil to rise up and burn. On the other hand, if the snow is less porous, most of the oil layer remains on the surface, approaching the case of an ice bed. However, the melting of snow due to flame heat flux causes a circulating flow pattern of the oil, whereby the hot layer at the surface moves down and comes back up due to capillary action. These processes, which have not been observed in the earlier studies, are physically explained in this study. The implications to overall efficiency of the burning process, which represents the amount of crude oil left in the snow after the burning process is discussed. The results will ultimately improve the strategies and the net environmental benefit of, and by it the success of, oil clean-up after an accidental spill on snow.
4
Li, Muzi, and Luo Man. "The Volatility spillover effect between gold-oil ratio and S&P 500 index." Thesis, Umeå universitet, Handelshögskolan vid Umeå universitet (USBE), 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-116839.
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Woodbury, Simon Edward. "Application of gas chromatography combustion-isotope ratio mass spectrometry to the detection of adulteration of vegetable oils." Thesis, University of Bristol, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.246268.
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Haglund, Fredrik, and Svensson Johan. "The volatility race in Commodities : The optimal hedge ratio in Copper, Gold, Oil and Cotton." Thesis, Jönköping University, JIBS, Business Administration, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-88.
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<p>Introduction: Companies that are dependent on different commodities as input or output are exposed to price risk in these commodities. The price changes can be expressed as volatility and higher volatility results in higher risk. Hedging the commodity contracts with futures can offset this risk. One of the most important questions in this field is to what extent the risk exposure should be hedged with futures contract, i.e. the optimal hedge ratio.</p><p>Purpose: The study aims to conduct an analysis of the variance in different commodities contracts and provide evidence of the optimal hedge ratio in the respective commodities.</p><p>Method: We used a quantitative study with daily spot and futures price changes of Copper, Gold, Cotton and Oil. We investigated the 6-month hedging behaviour where timeseries were created for the period January-June each year during 2001-2004. We used a simple linear regression of the futures and spot price changes and a minimum variance model in order to calculate the optimal hedge ratio.</p><p>Conclusion: Companies that are dependent on Copper, Gold, Cotton and Oil can significantly reduce the risk by engaging in futures contracts. The optimal hedge ratio for Copper is (96%), Gold (52%), Cotton (96%) and Oil (88%). By applying the optimal hedge ratio, a company may reduce their risk exposure up to 90% compared to an unhedged position.</p>
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Biju, Dona. "A parametric study of oil-jet lubrication in gear wheels." Thesis, Linköpings universitet, Mekanisk värmeteori och strömningslära, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-150786.
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A parametric study of oil-jet lubrication in gear wheels is conducted using Computational Fluid Dynamics (CFD) to study the effect of the different design parameters on the cooling performance in a gearbox. Flow in oil jet lubrication is found to be complex with the formation of oil ligaments and droplets. Various hole radii of 1.5, 2 and 2.5 mm along with five oil velocities is analyzed and it is found that at lower volumetric rates, velocity has more effect on the cooling and at higher volumetric rates, hole size has more effect on the cooling. At higher velocities, the heat transfer is much greater than the actual heat production in the gear wheel, hence these velocity ratios are considered less suitable for jet lubrication. At low velocity ratios of below 2, the oil doesn’t fully impinge the gear bottom land and the sides leading to low cooling. Based on the cooling, impingement length and amount of oil lost to the casing surface, 2 mm hole with a velocity ratio of 2.225 is selected for a successful oil jet lubrication. Varying the inlet position in X, Y and Z directions (horizontal, vertical and lateral respectively) is found to have no improvement on the cooling. Making the oil jet hit the gear wheel surface at an angle is found to increase the cooling. Analysis with the use of a pipe to supply oil was conducted with circular and square inlet and it was found that the heat transfer decreases in both cases due to the splitting of oil jet caused by the combination of the effects of high pressure from the pipe and vorticity in the air field. A method has been developed for two gear analysis using overset meshes which can be used for further studies of jet lubrication in multi-gear systems. Single inlet is found to be better for cooling two gear wheels as it would require a reduced volumetric flow rate compared to double inlets. Oil system requirements for jet lubrication was studied and it was concluded that larger pumps have to be used to provide the high volumetric rates and highly pressurized oil required. On comparing the experimental losses from dip lubrication and the analytical losses for jet lubrication, dip lubrication is found to have lesser loses and more suitable for this case. Good quality lubrication would reduce the fuel consumption and also increase the longevity of gearboxes and hence more research into analyzing alternate lubrication systems can be carried out using the results from this thesis.
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Chong, Emeline E. "Development of a 2-D black-oil reservoir simulator using a unique grid-block system." Texas A&M University, 2004. http://hdl.handle.net/1969.1/3334.
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The grid orientation effect is a long-standing problem plaguing reservoir simulators that employ finite difference schemes. A rotation of the computational grids yields a substantially different solution under certain circumstances. For example, in a five-spot pattern, the predicted recovery, water cut performance and the locations of the fronts depend on the type of grid system used. A Cartesian grid with one axis parallel to the line joining an injector and producer gives a solution significantly different from a grid that has the axes oriented at 45° to this line.
This study develops a unique grid-block assignment where rectangular grid blocks are interspersed with octagonal grid blocks. This grid block system is called the Hybrid Grid Block (HGB) system. The objective of this study is to evaluate the grid orientation effect of the HGB grid to see whether it is an improvement over the conventional Cartesian grid system.
In HGB, flow can progress in four directions in the octagonal grid blocks and two in the square grid blocks. The increase in the number of flow directions in the octagonal grid blocks is expected to reduce the grid orientation effect in the model. Hence, this study also evaluates the grid orientation effect of the HGB and compares it with the Cartesian grid system.
To test the viability of HGB, a general purpose finite difference IMPES-formulated two-dimensional black oil simulator was developed in this study, while retaining the familiar finite-difference discretization of the flow equations. Several simulation cases were conducted to compare HGB and conventional grid block systems. Comparisons with commercial simulator are also made. Despite the fact that the reservoir is isotropic and homogeneous, grid orientation effect was still observed when rectangular Cartesian grid models are run at mobility ratio, M = 1.0. Grid refinement can help to reduce the grid orientation effect in rectangular Cartesian grid models when there are favorable mobility ratios, i.e. M = 1.0 or less. However, at an unfavorable mobility ratio of M = 10.0, it is found that neither parallel nor diagonal orientation can be used reliably for the displacement problems run in this study. This is because as the number of grid blocks is increased, the performance of diagonal and parallel models actually diverges for the grid spacings investigated here. On the other hand, HGB grid is able to reduce the grid orientation effect even for unfavorable mobility ratio displacement problems (up to M = 50.0), with maximum relative difference in pore volume recovered of 6% between parallel and diagonal HGB grid models for all the cases run in this study. Comparisons between the conventional Cartesian and HGB grid show that the HGB grid is more effective in reducing the grid orientation effect than the Cartesian grid. The HGB grid performs better by consistently giving a smaller relative difference between HGB parallel grid and HGB diagonal grid in pore volume recovered (6.0, 4.5, 3.3, and 2.2%) compared to the relative difference between Cartesian parallel grid and Cartesian diagonal grid in pore volume recovered (17.0, 13.0, 9.3, 7.9%) at similar averaged area per grid block for all the four comparison cases studied.
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Winborn, Lorne Derek. "The cold operation of SI engines and the significance of fuel losses, oil dilution and mixture gas/fuel ratio." Thesis, University of Nottingham, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.366597.
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Garcia-Blanco, Susana. "Testing the Resource-Ratio Theory As A Framework Supporting A Bioremediation Strategy For Clean-Up Of Crude Oil-Contaminated Environments." University of Cincinnati / OhioLINK, 2004. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1098275222.
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Graviss, Matthew Sheridan. "The influence of a central groove on static and dynamic characteristics of an annular liquid seal with laminar flow." Thesis, Texas A&M University, 2005. http://hdl.handle.net/1969.1/2359.
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This thesis provides experimental static and dynamic results for four pairs of
seals, including a pair of smooth seals and three pairs of centrally grooved seals. The
grooved seals have groove depth to clearance ratios (Dg/C) of 5, 10, and 15. The radial
clearance of each test seal is 0.0891 mm. Test conditions include three shaft rotational
speeds from 4000 to 10000 rpm, three inlet oil pressures from 24 to 70 bars, and seal
dimensionless eccentricities from 0 (centered) to 0.7. For each pair of test seals, dynamic
results include stiffness and damping coefficients; static results include stator position,
attitude angles, and seal leakage. Stiffness, damping, and leakage are compared among
the seal pairs with various groove depths. Results show that all rotordynamic coefficients
consistently decrease with increasing seal groove depths, and seal leakage remains
constant through varying groove depths. Additionally, a comparison is made between
experimental results of all test seals and XLLubeGT. XLLubeGT is a computer model
developed at Texas A&M University, which uses a Reynolds equation + energy equation
model to predict dynamic performance of a grooved seal. It operates on the assumption
that the groove is large enough to create separate lands within the seal, creating a zero or
negligible pressure perturbation across the seal. A comparison with XLLubeGT shows
that even the seal with the largest groove depth tested is not deep enough to agree with
XLLubeGT predictions.
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Melo, RadamÃs Bezerra. "Anti-inflammatory and antioxidant action of oil mixes of omega 9, 6 and 3 with low ratio omega-6/omega-3 and high ratio omega-9/omega-6 after dental extraction in rats." Universidade Federal do CearÃ, 2014. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=17575.
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CoordenaÃÃo de AperfeÃoamento de Pessoal de NÃvel Superior<br>Oil fatty acids omega-3 and omega-9 have anti-inflammatory and antioxidant activities, while the omega-6 has pro-inflammatory action. The aim of this study was to evaluate the presence of antioxidant and anti-inflammatory effects with high nutraceutical ratio of omega-9: omega-6, antioxidant properties, and low ratio omega-6: omega-3, anti-inflammatory properties three days after tooth extraction in rats. Thirty-two young Wistar rats with 270-310g were randomly divided into four groups of 8 animals: Group Sham, Saline Group, Isolipid Group, and Mix Test Group. The animals received 0.9% NaCl, Sham Group and Salina Group, or Isolipid Mix (alpha-linolenic acid - ALA) mixture containing omega-6: omega-3 oils (ratio 8:01) and omega-9: omega-6 (ratio 0.4:1), Isolipid group, or Mix Test (alpha-linolenic acid - ALA, docosahexaenoic acid - DHA, eicosapentaenoic acid - EPA) omega-6: omega-3 (ratio 1.4: 1) and omega-9: omega -6 (3.4:1 ratio), Mix Text Group by gavage 1.2g solutions for kg/day for four days before and three days after the extraction of the left mandibular first molar. Evaluation of edema generated by the surgical procedure and collected the perialveolar the site of tooth extraction and dental alveolar mucosa itself for laboratory testing were performed: myeloperoxidase, osteoclast count, concentrations of TNF-α and IL-1β, glutathione (GSH) and thiobarbituric acid reactive substances (TBARS). The Mix Test induced a significant decrease on post-operative edema, myeloperoxidase , osteoclasts count , GSH in blood and tissue, on tissue and plasma TBARS and on the TNF-αconcentration, but did not show significant difference on the IL-1β concentration at the third post-operative day. The gavage with the Mix Test showed anti-inflammatory and antioxidant actions after molar tooth extraction in rats.<br>Os Ãcidos graxos insaturados Ãmega-3 e Ãmega-9 possuem aÃÃo anti-inflamatÃria e antioxidante, enquanto o Ãmega-6 possui aÃÃo prÃ-inflamatÃria. O objetivo do presente estudo foi avaliar a aÃÃo antioxidante e anti-inflamatÃria do mix de Ãleos em concentraÃÃes nutracÃuticas com alta razÃo Ãmega-9: Ãmega-6, favorecendo aÃÃo antioxidante, e baixa razÃo Ãmega-6:Ãmega-3, favorecendo aÃÃo anti-inflamatÃria no terceiro dia pÃs exodontia em ratos. Foram utilizados trinta e dois ratos Wistar jovens com 270-310g distribuÃdos aleatoriamente em quatro grupos de 8 animais: Grupo Sham, Grupo SoluÃÃo Salina, Grupo mix isolipÃdico e Mix Teste. Os animais receberam NaCl 0,9%, Grupo Sham e Grupo SoluÃÃo Salina, ou mix isolipÃdico, (Ãcido alfa-linolÃico - ALA) mistura contendo Ãmega-6:Ãmega-3 Ãleos (relaÃÃo de 8:01) e Ãmega-9:Ãmega-6 (relaÃÃo 0,4:1), Grupo IsolipÃdico, ou Mix Teste (Ãcido alfa-linolÃnico - ALA, Ãcido docosahexaenÃico - DHA, Ãcido eicosapentaenÃico - EPA) de Ãmega-6:Ãmega-3 (relaÃÃo 1,4:1) e Ãmega-9:Ãmega -6 (3,4:1 relaÃÃo), Grupo Teste, receberam por gavagem 1,2g da soluÃÃo correspondente a cada grupo por kg/dia durante quatro dias antes e trÃs dias apÃs a exodontia do primeiro molar inferior esquerdo. Foi realizada a avaliaÃÃo do edema gerado pelo procedimento cirÃrgico e coletada a mucosa perialveolar ao sÃtio da extraÃÃo dental e o prÃprio alvÃolo dental para anÃlises laboratoriais: mieloperoxidase, contagem de osteoclastos, expressÃo do TNF-α e IL-1β, glutationa (GSH) e substÃncias reativas ao Ãcido tiobarbitÃrico (TBARS). O Mix Teste induziu uma diminuiÃÃo significante na atividade da mieloperoxidase,no edema pÃs operatÃrio, na contagem de osteoclastos, na GSH plasmÃtica e do tecido, nas concentraÃÃes plasmÃticas e do tecido de TBARS, na expressÃo do TNF-α, mas nÃo mostrou diferenÃa significante na expressÃo de IL-1β no terceiro dia pÃs-operatÃrio. A administraÃÃo por gavagem do Mix Teste demonstrou uma reduÃÃo da resposta inflamatÃria e oxidante, atuando como anti-inflamatÃrio e antioxidante, apÃs exodontia em ratos
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Karamerou, Eleni. "Bioprocessing strategies for the cultivation of oleaginous yeasts on glycerol." Thesis, University of Manchester, 2016. https://www.research.manchester.ac.uk/portal/en/theses/bioprocessing-strategies-for-the-cultivation-of-oleaginous-yeasts-on-glycerol(7a8cbfe6-b1e4-4910-a171-3a7990d862bd).html.
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Over recent years microbial oil has attracted much attention due to its potential to replace traditional oil sources in the production of biofuels and nutraceuticals. Its advantages arise from its independence of the food supply chain and its ease of production compared to conventional plant oils. Also, as concerns for the environment grow, microbially-synthesized oil emerges as potential competitor for the sustainable production of biodiesel. However, the high cost of its production currently hinders its large scale application. The bottlenecks to industrial microbial oil production are the cost of substrate and cultivation. Current research is focusing on process improvements to make microbial oil more competitive and worthwhile to produce. Several types of microorganisms have been explored so far and waste substrates have been utilised as cheap feedstocks. The overall cost is affected by the fermentation stage, therefore it is imperative to design cultivations with little operating requirements and high yields. Consequently, the present thesis aims to contribute to the field by developing and investigating a simple process for oleaginous yeast cultivation, focusing mainly on enhancing the yields during the bioreactor stage. Oleaginous yeasts were screened for their ability to grow on glycerol and the most promising strain was selected for further research. Then, the necessary conditions for its growth and oil accumulation were defined. Shake-flask cultivations showed that the specific growth rate and glycerol consumption of Rh. glutinis were higher at lower glycerol concentrations (smaller or equal to40 g/L), while higher C/N elemental ratios enhanced oil content. Experimental data were used to construct an unstructured kinetic model to describe and predict the system's behaviour. The Monod-based model took into account double substrate growth dependence and substrate inhibition. Following that, bioreactor cultivations extended the range of parameters studied, to include the influence of aeration rate and oxygen supply on cellular growth and microbial oil production. Cultivations at different air flow rates were performed in a 2 L bioreactor and showed that a low aeration rate of 0.5 L/min gave the best glycerol and nitrogen uptake rates, resulting in a concentration of biomass of 5.3 g/L with oil content of 33% under simple batch operation. This was improved by 68% to 16.8 g/L (cellular biomass) with similar oil content (34%) by applying a fed-batch strategy. Finally, different glycerol feeding schemes were evaluated in terms of their effect on oil accumulation. The concept of targeting first a cell proliferation stage, limited by the availability of nitrogen, followed by a lipid accumulation stage, fuelled by glycerol was tested. Continual feeding and pulsed feedings, delivering the same total amount of nitrogen (and glycerol), resulted in similar elevated values of both cellular biomass (~25 g/L) and oil content (~40%). Addition of glycerol at higher rates but giving the same total amount of nitrogen led to a further increase in oil content to 53%, resulting in an overall oil yield of more than 16 g/L (the highest achieved throughout the project). With comparable yields to those reported in the literature but achieved with a much poorer medium, there is every reason to be optimistic that microbial oil production from glycerol could be commercially viable in the future.
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Sassen, Douglas Spencer. "Pseudokarst topography in a humid environment caused by contaminant-induced colloidal dispersion." Thesis, Texas A&M University, 2003. http://hdl.handle.net/1969.1/455.
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Over fifty small sinkholes (~1 meter in depth and width) were found in conjunction with structural damage to homes in an area south of Cleveland, TX. The local geology lacks carbonate and evaporite deposits associated with normal sinkhole development through dissolution. The morphology and distribution of sinkholes, and the geologic setting of the site are consistent with piping erosion. However, the site lacked the significant hydraulic gradient or exit points for sediment associated with traditional piping erosion. In areas of sinkholes, geophysical measurements of apparent electrical conductivity delineated anomalously high conductivity levels that are interpreted as a brine release from a nearby oil-field waste injection well. The contaminated areas have sodium adsorption ratios (SAR) as high as 19, compared to background levels of 3. Sodium has been shown to cause dispersion of soil colloids, allowing for sediment transport at very low velocities. Thus, subsurface erosion of dispersed sediment could be possible without significant hydraulic gradients. This hypothesis is backed by the observation of the depletion of colloidal particles within the E-horizon of sinkholes. However, there is a lack of precedence of waste brines initiating colloid dispersion. Also, sodium dispersion is not thought to be an important process in piping erosion in humid settings such as this one. Therefore, laboratory experiments on samples from the site area, designed to simulate field conditions, were conducted to measure dispersion verses pH, SAR and electrical conductivity (EC). Analysis of the experimental data with neural networks showed that an increase in SAR did increase dispersion. A dispersion prediction map, constructed with the trained neural network and calibrated geophysical data, showed correlation between sinkhole locations and increased predicted dispersion. This research indicates that a contaminant high in sodium content has caused colloidal dispersion, which may have allowed nontraditional subsurface erosion to occur in an area lacking a significant hydraulic gradient.
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Orire, Endurance. "The techno-economics of bitumen recovery from oil and tar sands as a complement to oil exploration in Nigeria / E. Orire." Thesis, North-West University, 2009. http://hdl.handle.net/10394/5704.
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The Nigeria economy is wholly dependent on revenue from oil. However, bitumen has been discovered in
the country since 1903 and has remained untapped over the years. The need for the country to
complement oil exploration with the huge bitumen deposit cannot be overemphasized. This will help to
improve the country's gross domestic product (GDP) and revenue available to government. Bitumen is
classifled as heavy crude with API (American petroleum Institute) number ranging between 50 and 110
and occurs in Nigeria, Canada, Saudi Arabia, Venezuela etc from which petroleum products could be
derived.
This dissertation looked at the Canadian experience by comparing the oil and tar sand deposit found in Canada with particular reference to Athabasca (Grosmont, Wabiskaw McMurray and Nsiku) with
that in Nigeria with a view of transferring process technology from Canada to Nigeria. The Nigeria and Athabasca tar sands occur in the same type of environment. These are the deltaic, fluvial marine deposit in an incised valley with similar reservoir, chemical and physical properties. However, the Nigeria tar sand is more asphaltenic and also contains more resin and as such will yield more product volume during
hydro cracking albeit more acidic. The differences in the components (viscosity, resin and asphaltenes
contents, sulphur and heavy metal contents) of the tar sands is within the limit of technology adaptation.
Any of the technologies used in Athabasca, Canada is adaptable to Nigeria according to the findings of this research.
The techno-economics of some of the process technologies are. x-rayed using the PTAC (petroleum
technology alliance Canada) technology recovery model in order to obtain their unit cost for Nigeria
bitumen. The unit cost of processed bitumen adopting steam assisted gravity drainage (SAGD), in situ
combustion (ISC) and cyclic steam stimulation (CSS) process technology is 40.59, 25.00 and 44.14
Canadian dollars respectively. The unit cost in Canada using the same process technology is 57.27, 25.00
and 61.33 Canadian dollars respectively. The unit cost in Nigeria is substantively lesser than in Canada.
A trade off is thereafter done using life cycle costing so as to select the best process technology for the
Nigeria oil/tar sands. The net present value/internal rate of return is found to be B$3,062/36.35% for
steam assisted gravity drainage, B$I,570124.51 % for cyclic steam stimulation and B$3,503/39.64% for in
situ combustion. Though in situ combustion returned the highest net present value and internal rate of
return, it proved not to be the best option for Nigeria due to environmental concern and response time to
production. The best viable option for the Nigeria tar sand was then deemed to be steam assisted gravity
drainage.
An integrated oil strategy coupled with cogeneration using MSAR was also seen to considerably amplify
the benefits accruable from bitumen exploration; therefore, an investment in bitumen exploration in
Nigeria is a wise economic decision.<br>Thesis (M.Ing. (Development and Management))--North-West University, Potchefstroom Campus, 2010.
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Samadov, Hidayat. "Analyzing Reservoir Thermal Behavior By Using Thermal Simulation Model (sector Model In Stars)." Master's thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12613336/index.pdf.
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It is observed that the flowing bottom-hole temperature (FBHT) changes as a result of production, injection or shutting the well down. Variations in temperature mainly occur due to geothermal gradient, injected fluid temperature, frictional heating and the Joule-Thomson effect. The latter is the change of temperature because of expansion or compression of a fluid in a flow process involving no heat transfer or work. CMG STARS thermal simulation sector model developed in this study was used to analyze FBHT changes and understand the reasons. Twenty three main and five additional cases that were developed by using this model were simulated and relation of BHT with other parameters was investigated. Indeed the response of temperature to the change of some parameters such as bottom-hole pressure and gas-oil ratio was detected and correlation was tried to set between these elements. Observations showed that generally FBHT increases when GOR decreases and/or flowing bottom-hole pressure (FBHP) increases. This information allows estimating daily gas-oil ratios from continuously measured BHT. Results of simulation were compared with a real case and almost the same responses were seen. The increase in temperature after the start of water and gas injection or due to stopping of neighboring production wells indicated interwell communications. Additional cases were run to determine whether there are BHT changes when initial temperature was kept constant throughout the reservoir. Different iteration numbers and refined grids were used during these runs to analyze iteration errors<br>however no significant changes were observed due to iteration number differences and refined grids. These latter cases showed clearly that variations of temperature don&rsquo<br>t occur only due to geothermal gradient, but also pressure and saturation changes. On the whole, BHT can be used to get data ranging from daily gas-oil ratios to interwell connection if analyzed correctly.
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Freitas, Andréa Gonçalves Bueno de. "Modelagem e simulação do tratamento de água oleosa usando hidrociclones." Universidade Federal de Sergipe, 2012. https://ri.ufs.br/handle/riufs/5058.
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The increase of the industrial pollution has been carrying the organs of environmental control to review the legislation in force and to limit in a more rigorous form the discards of industrial effluent. As opposed, the companies have been improving the treatment systems of their
effluent, applying new technologies. In the petroleum industry, in the oil-water separation, are used floatation chamber and hydrocyclones. The floatation seeks to recover the oil residue through gravitational separation, while the hydrocyclones try to accelerate this process with
the use of the centrifugal force. The hydrocyclones in study are equipment constituted of a cylindrical part and two conic parts joint, in which the supply is constituted by two entrances involute, diametrically opposite, presenting a normal axis to the equipment and positioned tangentially to the lateral wall of the cylinder. The separator has two openings for exit, axis positioned to the equipment, one of them, called overflow, placed near to the supply section
and to another, called underflow, placed near to the vertex of the conic body of the hydrocyclone. The analysis of the fluid-dynamic behavior of the hydrocyclone was led
through the numeric simulation of the treatment of water produced, applying methods of Computational Fluid-dynamic (CFD). In the used computational tool, CFX, it is possible to build the geometry, draw the numeric mesh, adjust the simulation parameters, solve and to analyze the results, being able to be applied for several kinds of flow. It accomplished an experimental planning with the goal of analyzing the influence of the geometry in the
separation efficiency of the hydrocyclone, in other words, know which variables were more important for the separation efficiency. To evaluate the performance of the equipment were calculated the Flow Ratio (Rf) and the Reduced Grade Efficiency (G ), for each geometry. Due to the great number of tested variables, whatever Dc, Do, Du, Hc, VF e L1 it opted to not analyze the effect of each one in separated, but the interactions of these. The different numeric simulations were considered as computational experiments. In all the 19 computational experiments, the simulations were initiated with the turbulence model k-e, these last used as initial values for the simulations with the turbulence model SSG, because
this last is what best represents the flow in the hydrocyclone. The analyses done in the Essential Regression show that the variables which the most influence the separation efficiency are the overflow and underflow diameters. The reduced grade efficiencies stayed
well distributed in the range 0-96%, what shows that the choice of the size of tried drop (250 mm) was adequate. The greatest reason values of fluid were obtained for Do/Du @ 1.0 and the minors, excluding Rf = 0, for Do/Du @ 0.2. In the studied intervals, the greatest Reduced
Grade Efficiency values are obtained with the biggest values of Do and the smallest of Du. The smallest results of Flow Ratio are obtained with the smallest values of Do and the biggest values of Du.<br>O aumento da poluição industrial tem levado os órgãos de controle ambiental a rever a legislação em vigor e a limitar de forma mais rigorosa o descarte de efluentes industriais. Em contrapartida, as empresas têm melhorado os sistemas de tratamento de seus efluentes, aplicando novas tecnologias. Na indústria de petróleo, na separação óleo-água, são usados flotadores e hidrociclones. A flotação procura recuperar o resíduo de óleo através de
separação gravitacional, enquanto que os hidrociclones procuram acelerar este processo com o uso da força centrífuga. Os hidrociclones em estudo são equipamentos constituídos de uma parte cilíndrica e duas partes cônicas justapostas, nas quais a alimentação é constituída por
duas entradas em voluta, diametralmente opostas, apresentando um eixo normal ao do equipamento e posicionada tangencialmente à parede lateral do cilindro. O separador tem duas aberturas para saída, posicionadas axialmente ao equipamento, uma delas, chamada overflow, situada próxima à seção de alimentação e a outra, chamada underflow, situada próxima ao vértice do corpo cônico do hidrociclone. A análise do comportamento
fluidodinâmico do hidrociclone foi conduzida através da simulação numérica do tratamento da água produzida, aplicando-se métodos de Fluidodinâmica Computacional (CFD). Na ferramenta computacional utilizada, CFX, é possível construir a geometria, desenhar a malha numérica, ajustar os parâmetros de simulação, resolver e analisar os resultados, podendo ser aplicado para diversos tipos de escoamento. Realizou-se um planejamento experimental com o objetivo de analisar a influência da geometria na eficiência de separação do hidrociclone, ou
seja, saber quais variáveis eram mais relevantes para a eficiência de separação. Para avaliar o desempenho do equipamento foram calculadas a Razão de Fluido (Rf) e a Eficiência Granulométrica Reduzida (G ), para cada geometria. Devido ao grande número de variáveis testadas, quais sejam Dc, Do, Du, Hc, VF e L1 optou-se por não analisar o efeito de cada uma em separado, mas a interações destas. As diferentes simulações numéricas foram consideradas como experimentos computacionais. Em todos os 19 experimentos
computacionais, as simulações foram iniciadas com o modelo de turbulência k-, estas últimas utilizadas como valores iniciais para as simulações com o modelo de turbulência SSG, pois este último é o que melhor representa o escoamento no hidrociclone. As análises feitas no Essential Regression mostram que as variáveis que mais influenciam a eficiência de separação são os diâmetros de overflow e de underflow. As eficiências granulométricas reduzidas ficaram bem distribuídas na faixa 0-96%, o que mostra que a escolha do tamanho
de gota testado (250 mm) foi adequada. Os maiores valores de razão de fluido foram obtidos para Do/Du @ 1,0 e os menores, excluindo-se Rf = 0, para Do/Du @ 0,2. Nos intervalos estudados, os maiores valores de Eficiência Granulométrica Reduzida são obtidos com os
maiores valores de Do e os menores de Du. Os menores resultados de Razão de Fluido são obtidos com os menores valores de Do e os maiores valores de Du.
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Karalazos, Vasileios. "Sustainable alternatives to fish meal and fish oil in fish nutrition : effects on growth, tissue fatty acid composition and lipid metabolism." Thesis, University of Stirling, 2007. http://hdl.handle.net/1893/220.
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Traditionally, fish meal (FM) and fish oil (FO) have been used extensively in aquafeeds, mainly due to their excellent nutritional properties. However, various reasons dictate the use of sustainable alternatives and the reduction of the dependence on these commodities in fish feeds. Hence, the aim of the present thesis was to investigate the effects of the replacement of FM and FO with two vegetable oils (VO) and an oilseed meal on the growth performance, feed utilization, nutrient and fatty acids (FA) digestibility and tissue FA composition and metabolism in three commercially important European fish species. Specifically, in Experiment I crude palm oil (PO) was used to replace FO in diets for rainbow trout. In Experiments II and III FO was replaced with rapeseed oil (RO) in diets for Atlantic salmon at various dietary protein/lipid levels aiming also at further reductions of FM by using low protein (high lipid) diet formulations. In Experiments II and III the fish were reared at low and high water temperatures, respectively, in order to elucidate, also, the potential effects of temperature. Lastly, the effects of the replacement of FM with full fat soya meal (FFS) in Atlantic cod were investigated in Experiment IV. The results of the present thesis showed no negative effects on growth performance and feed utilization in rainbow trout when FO was replaced with PO. The dietary inclusion of RO improved the growth of Atlantic salmon, possibly, due to changes in the nutrient and FA digestibilities and FA catabolism while, the growth and feed utilization were unaffected by the dietary protein/lipid level. However, the growth of Atlantic cod was affected negatively by the replacement of FM with FFS. The proximate composition of the fish whole body was in most cases unaffected by dietary treatments. The changes in dietary formulations affected the dietary FA compositions and resulted in significant changes in the fish tissue FA compositions. It was clearly shown that the fish tissue total lipid FA composition reflects the FA composition of the diet, although specific FA were selectively utilized or retained in the tissues by the fish. These may have serious implications not only for fish metabolism and growth but also for the quality of the final product, especially in terms of possible reductions of n-3 HUFA.
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Engström, Daniel, and Niklas Gustafsson. "Swedish Equity Sectors Risk Management with Commodities : Revisiting dynamic conditional correlations and hedge ratios." Thesis, Linköpings universitet, Nationalekonomi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-139040.
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The purpose of this study is to investigate changes in dynamic conditional correlations between Swedish equity sector indices and commodities using oil, gold, copper and a general commodity index. Additionally the purpose is to evaluate which of the two methods, DCC- GARCH or GO-GARCH that is more efficient in estimating correlation for hedge ratio calculation. Daily data on the FTSE30 index of Sweden and its sector indices have been studied between the years 1994 and 2017. A DCC-GARCH (1,1) and GO-GARCH (1,1) model with one autoregressive term AR(1) using multivariate Student t- and Multivariate Affine Negative Inverse Gaussian distribution were used to estimate conditional correlations. Correlations between Swedish FTSE30, its sector indices and commodities are considerably lower than previous research has found American or emerging markets correlation with commodities to be. This suggests better diversification opportunities with commodities for the Swedish market. Optimal hedge ratios (OHR) was calculated and back tested using a rolling window analysis with 1000 days forecast length and 20 days re-estimation window and evaluated using a calculated hedge effectiveness index (HE). Determined by HE, copper is the best hedge for the Swedish composite FTSE30 and sector indices using conditional correlation from the GO-GARCH during the data period. Gold is considered as a semi-strong safe haven due to its negative correlation with all sectors. Additionally, this study identifies a temporarily large increase in the correlation between the Swedish equities sectors and composite index with commodities around the years 2015/2016. This study also emphasizes the difference between stressful and calm periods in the market.
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Boris, Župan. "UTICAJ DODATKA LANENOG ULJA U HRANI NA PROMENU SADRŽAJA MASNIH KISELINA U MIŠIĆNOM TKIVU ŠARANA." Phd thesis, Univerzitet u Novom Sadu, Poljoprivredni fakultet u Novom Sadu, 2016. https://www.cris.uns.ac.rs/record.jsf?recordId=97698&source=NDLTD&language=en.
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Cilj istraživanja bio je da se utvrdi u kojoj meri dodavanje lanenog ulja u peletirane krmnesmješe i ishrana tovnog šarana tako obogaćenom hranom utječe na količinu masti ikompoziciju masnih kiselina u mesu ribe. Krmne smješe u svim grupama istraživanja su bileistog sirovinskog sastava, osim dodatka lanenog ulja koje se menjalo (2,0; 3,0; 4,0; 5,0% i 6%u drugom ogledu) i masti (Magnapac) koja je smanjivana za istu postotnu vrednost dodatkomlanenog ulja. Većim delom istraživanog razdoblja fizičko-hemijski parametri vode su u svimekspermentalnim ribnjacima varirali u pogodnim vrednostima za uzgoj toplovodnih riba. UdioC18:1 cis-9 statistički je značajno najniži u kontrolnoj grupi i iznosi 35,43%. Povećanjemvrednosti lanenog ulja povećava se i udio C18:1 cis-9. Statistički najviša vrednost C20:0 je koduzoraka hranjenih s dodatkom 5% lanenog ulja. Najniža vrednost C20:3 ω-3 je u kontrolnojgrupi i iznosi 0,22% a značajno najviša u grupi koja se hrani s dodatkom 5% lanenog ulja. Sobzirom na dodatak lanenog ulja u hrani, nema značajnih razlika kod ukupnih zasićenih,mononezasićenih, polinezasićenih i omega-6 masnih kiselina. Najveći udio ω-3 masnihkiselina utvrđen je u uzorcima šarana kojima je u hranu dodano 5% lanenog ulja (5,41%) Udrugom ogledu utvrđena je opravdanost upotrebe lanenog ulja u hrani za ribe u odnosu naefekte koji su dobijeni u mesu. Omjer ω-3/ω-6 masnih kiselina značajno se povećao u grupamakojima je u hranu dodat veći dio lanenog ulja (0,21 u kontrolnoj grupi do 0,30% u grupi sdodatkom 5% lanenog ulja). Vrednostiholesterola se nisu značajno menjale dodavanjemlanenog ulja u ishrani šarana.<br>The aim of this study was to determine to what extent adding flaxseed oil to pellet diet andfattening carp so enriched food affects the amount of fat and the composition of fatty acids infish meat. Feed mixtures in all the studied groups were the same composition, except for theaddition of linseed oil to be changed (2.0; 3.0; 4.0; 5.0% and 6%) and fat (Magnapac), whichwas reduced by the same percentage value addition linseed oil. During substantial period ofresearch physico-chemical parameters of water in all experimental ponds ranged in valuessuitable for the cultivation of warm-water fish. Share C18:1 cis-9 was statistically significantlylowest in the control group and amounted 35.43%. By increasing the value of flaxseed oilincreases the proportion of C18:1 cis-9. Statistical highest value of C20:0 in the samples fedwith the addition of 5% linseed oil. The lowest value of C20:3 ω-3 in the control group is0.22% and significantly highest in the group that feeds supplemented with 5% linseed oil. Dueto the addition of linseed oil in the food, there is no significant difference in total saturated,monounsaturated, polyunsaturated omega-6 fatty acids. The largest proportion of ω-3 fattyacids found in samples of carp which was in food supplemented with 5% linseed oil (5.41%).The experimental results of the second experiment show the usefulleness of using of linseed oilin fish food regearging the meat quality. The ratio ω-3/ω-6 fatty acid increased significantly inthe group that is added to food in a higher proportion of linseed oil (0.21 in the control groupto 0.30% in the group with addition of 5% linseed oil). The value of cholesterol was notsignificantly changed by adding linseed oil to the diet of carp.Accepted on Senate on:AS
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Fischer, Herbert. "Oil recovery by spontaneous imbibition for a wide range of viscosity ratios." Laramie, Wyo. : University of Wyoming, 2006. http://proquest.umi.com/pqdweb?did=1225153481&sid=1&Fmt=2&clientId=18949&RQT=309&VName=PQD.
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Retief, PJ. "Dedicated radio-communication system for Soekor's oil exploration along the South African coastline." Thesis, Cape Technikon, 1989. http://hdl.handle.net/20.500.11838/1074.
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Thesis (Masters Diploma( Technology)) --Cape Technikon, Cape Town, 1989<br>Soekor's exploration programme has moved totally offshore and expanded greatly in the past few years. Use of computers necessitated the exchange of data between offshore and land installations. At the same time the exploration programme is moving further offshore While the coastal. stations of the Post & Telecommunications can not handle the volume of traffic that the oil drills present nor the data modes. A study of the transmission requirements revealed that a minimum of one voice channel per drill must be available at all times, While Some 20M byte of data per oil drill per year will be transmitted. Facsimile will be needed at times, also as a back-up for the data systems. A study of publications revealed that only five of the eleven methods studied where viable, namely VHF-EM, satellite, HF-telephony, HF-teleprinter and HF-data. These possibilities as well as their practical implementation were studied in depth. The effect of the atmospheric conditions on the propagation of VHF-signals around the coastline was studied and 17 sites identified and evaluated from the mouth of the Orange River to Port Elizabeth in respect of coverage, accessibility, facilities and cost. INMARSAT facilities and costs were evaluated as well as HF-systems. Finally a system was designed consisting of HF-telephony, separate "packet" HF radio data system, satellite telephony back-up and satellite high speed data as well as a limited VHF system. The entire system is complemented by marine telephony and telegraphy equipment. On-going system guidance in the form of propagation predictions is provided. Some existing equipment was used, While R950 000 has been spent to date on additional equipment.
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Pinto, Ciro de Miranda. "ConfiguraÃÃo e antecipaÃÃo de plantio da mamona em consÃrcio com a cultura do girassol." Universidade Federal do CearÃ, 2011. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=6541.
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CoordenaÃÃo de AperfeiÃoamento de NÃvel Superior<br>A mamoneira (Ricinus communis) Ã tolerante a seca e cultivada para produÃÃo de Ãleo para uso industrial. Na regiÃo Nordeste os pequenos produtores cultivam a mamona consorciada algodÃo, feijÃo caupi, gergelim, girassol, milho, sorgo ou amendoim. Dois experimentos de campo foram conduzidos nos anos agrÃcolas 2008, 2009 e 2010, na Fazenda Experimental Lavoura Seca, QuixadÃ, CearÃ, com o objetivo de avaliar o comportamento da mamona e girasssol cultivados em dois padrÃes de consorciaÃÃo. No experimento I avaliou-se o consorcio mamona (Ma) x girassol (Gi) com 1Ma:1Gi; 1Ma:2Gi; 1Ma:3Gi; 2Ma:2Gi; 2Ma:3Gi fileiras, acrescidos da mamona e girassol em monocultivo. No experimento II, avaliou-se o consorcio mamona x girassol com antecipaÃÃo do plantio da mamona em 0, 7, 14 ou 21 dias antes do plantio do girassol. Para cada experimento adotou-se o delineamento de blocos ao acaso com 4 repetiÃÃes. Avaliou-se a produtividade de grÃos, seus componentes e o uso eficiente da terra para a mamona e girassol consorciados e em monocultivo. A produtividade da mamona e girassol no monocultivo foi significativamente superior nos dois sistemas de consÃrcio. A antecipaÃÃo do plantio da mamona 14 e 21 dias em comparaÃÃo ao girassol mostraram vantagens em relaÃÃo as demais datas de plantio. No experimentos I e II verificou-se que a mamona foi dominante sobre ao girassol. PrecipitaÃÃes pluviais inferiores a demanda hÃdrica das culturas da mamona e girassol, proporcionaram reduÃÃo no uso eficiente de terra (UET).<br>Castor bean (Ricinus communis L.) is an oil seed crop drought tolerant with its oil having several uses in industry. In the Northeast of Brazil it is commonly cultivated by small farmers intercropped with cotton, cowpea, sesamum, sunflower, sorghum or peanuts. Two field experiments were carried during 2008, 2009 and 2010, at â Fazenda Experiental Lavoura Secaâ, Quixada, Ceara, with the objective to evaluate the behavior of castor bean and sunflower under two intercropping arrangements. In experiment I, its was evaluated the intercropping castor bean (CB) x sunflower (SF) with 1CB:1SF; 1CB:2SF; 1CB:3SF; 2SB:2SF; 2CB:3SF rows, added of sole crop of castor bean and sunflower. In the experiment II, was evaluated with the early planting of castor bean in 0, 7, 14 or 21 days in relations to sunflower the intercropping systems. In both experiments it was used a randomized complete block design with 4 replications. In this study it was determined the yield, yield components and land equivalent ratio (LER) for castor bean and sunflower grown in intercropping and sole crop. The grain yield of castor bean and sunflower was significantly higher in sole crop than intercropping in both experiments. Between the intercropping systems the highest yields were observed when early planting of castor bean was of 14 or 21 days before sunflower. In experiments I and II, showed that the castor bean was the dominant crop in relation to sunflower. Rainfall lower the water requirements of castor bean and sunflower crops, showed a reduction in LER.
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Kulkarni, Prashant S. "Mixed Hydrophilic/Hydrophobic Fiber Media for Liquid-Liquid Coalescence." University of Akron / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=akron1310686055.
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Boggs, Cheryle Ann. "Glacial Drift Thickness and Vs Characterized Using Three-Component Passive Seismic Data at the Dominion Stark-Summit Gas Storage Field, North Canton, Ohio." Wright State University / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=wright1420815127.
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Abrahams, Celeste H. "Modulation of colon carcinogenesis by dietary ω-6/ω-3 fatty acid ratios : a chemopreventive strategy?" University of the Western Cape, 2015. http://hdl.handle.net/11394/5323.
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Philosophiae Doctor - PhD<br>The aim of this study was to determine whether dietary fats constituting specific ω-6/ω-3 fatty acids (FA) ratio has chemopreventive modulating effects on the development of colon cancer. Western diets intake of saturated FA (SATS) and ω-6 polyunsaturated FA (PUFA) are very high relative to low ω-3 PUFA consumption. This high ω-6 and low ω-3 FA intake, resulting in a high ω-6/ω-3 FA ratio, appears to have a promoting effect on disease outcome, whilst increased ω-3 FA intake exhibiting anti-cancer effects. An animal cancer model was employed to evaluate the effects of dietary fat ratios on chemically induced carcinogenesis during cancer promotion. This was to determine whether the FA diets have a promoting or inhibitory effect on early neoplastic lesions by quantifying aberrant crypt foci (ACF) development and monitoring the crypt cells proliferative and apoptotic indices. The expressions of genes associated with changes in cells redox balance were also assessed. Common dietary fats were combined to produce the dietary fat ratios: sunflower oil (S), borage oil (B) and fish oil (F). Combinations of these oils generated the different ω-6/ω-3 FA ratios: SB (ω-6/ω-3: 38:1), SF (ω-6/ω-3: 13:1) and SBF (10:1). To represent the Western diet's high ω-6/ω-3 FA ratio profile, S (ω-6/ω-3: 501: 1) was used as a control, and canola oil and olive oil as additional reference. The dietary fats had no toxic effects on the liver and kidney based on serum clinical biochemical measurements. Diets containing borage oil (SB and SBF diets), canola and olive oil decreased (p<0.05) the crypt multiplicity of large (≥7 crypts/focus) ACF, exhibiting anti-cancer effects by decreasing (p<0.05) the proliferative activity of the rat colon crypts. Borage oil's protective effect resulted from the enhanced supply of C18:3ω-6 that has anti-inflammatory and anti-proliferative properties. The observed decrease (p<0.05) in apoptosis in the ACF was also facilitated by the up- and down-regulation of DNA repair and DNA replication associated genes, Xpa and Ercc2 by borage oil, respectively. Canola oil and olive had the largest inhibitory effect on suppressing crypt multiplicity by reducing (p<0.05) proliferation in the colon. Both oils effected the up-regulation (p<0.05) of the expression of several oxidative stress and anti-oxidant defence genes mediating the regulation of cell proliferation. The increased supply of C18:1ω-9 (canola and olive) and total polyphenolic content (olive) protected cells against oxidative stress induced apoptosis, which provided interesting interactive effects between FA and polyphenolic oil constituents that should be further elucidated. In contrast, the fish oil containing (SF diet) and the control sunflower (S diet) increased (p<0.05) the total ACF and colon crypt multiplicity (≥7 crypts/focus) when compared to the SB, SBF, olive oil and canola oil diets. An increased resistance to oxidative stress induced apoptosis appears to facilitate fish oil’s enhancing effect on crypt multiplicity despite the increased supply of LC ω-3 FA, which are prone to oxidation and leads to increased oxidative stress. This protective effect on crypt multiplicity and ACF development was mainly due to enhanced cellular antioxidant and DNA repair responses through the up-regulation (p<0.05) of Gpx4 and Nudt1, which favoured the increase (p<0.05) of crypt cells proliferation.The in vitro study demonstrated that oil ratio emulsions (S: ω-6/ω-3 = 249:1; SB: ω-6/ω-3 = 28:1; SF: ω-6/ω-3 = 12:1 and SBF: ω-6/ω-3 = 12:1) had differential effects on the survival indices of HT-29 and Caco-2 colon cancer cells. Contrary to the in vivo model, fish oil (SF and SBF emulsions) significantly (p<0.05) reduced the viability and proliferation of both cell lines, with the HT-29 cells showing greater sensitivity to the oil’s anti-proliferative effect. The HT-29 cells exposure to increased levels of C20:5ω-3 and C22:6ω-3 predisposes it to lipid peroxidation that increases the potential for cell removal via apoptosis. However, apoptotic effects were absent due to the HT-29 cells removal via necrosis as the cells energy status (ATP production) was significantly (p<0.05) depleted. Similar to the animal cancer model, borage oil (SB and SBF emulsions) had a reducing (p<0.05) effect on cell proliferation in both cell lines. However, as ATP was decreased (p<0.05), the S, SF and SBF emulsions resulted in an increased (p<0.05) apoptotic response in the Caco-2 cells in a dose dependent manner. This response resulted from the altered FA and lipid composition effected by the oil emulsions. Increased (p<0.05) incorporation of C20:5ω-3 and C22:6ω-3 in membrane phospholipid, phosphatidylethanolamine (PE), resulted in a significant decrease (p<0.05) in total SATS and MUFA content. A decrease (p<0.05) in membranes ω-6/ω-3 FA ratio was noted as well. This effect seems to selectively favour the induction of apoptosis by borage oil (SB and SBF). Similarly, an increase (p<0.05) in the PC/PE ratio by all oil emulsions, and a decrease (S and SB) and increase (SF and SBF) (p<0.05) in the chol/PL ratio appears to facilitate apoptosis too. A different threshold of the FA and lipid composition parameters elicits the inhibition of cell proliferation utilising lower oil emulsion concentrations. Therefore, the dietary supply of fats characterised by a defined low ω-6/ω-3 FA ratio can selectively modulate the growth indices of colon cancer. Specific oil ratio combinations by incorporating borage oil and fish oil hereby provide a selective strategy for chemoprevention in the colon, although underlying interactions and threshold effects of specific FA seems to prevail that should be further unravelled.<br>Medical Research Council (MRC) and Cancer Association of South Africa (CANSA)
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Nasr, Emna. "Signatures inorganiques et isotopiques combinées pour la discrimination de l'origine géographique de l'huile d'olive." Electronic Thesis or Diss., Pau, 2022. http://www.theses.fr/2022PAUU3004.
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La mondialisation de l'industrie alimentaire a suscité l'intérêt des consommateurs pour l'origine géographique et la qualité des produits alimentaires. L'augmentation de la production et de la consommation mondiale de denrées alimentaires a toutefois entraîné la propagation de pratiques frauduleuses. Celles-ci menacent à la fois la santé des consommateurs et l'équilibre économique de l'industrie alimentaire, qui subit chaque année d'énormes pertes financières. L'huile d'olive est l'un des produits alimentaires les plus fraudés. En conséquence, un large éventail de stratégies analytiques a été proposé pour l'authentification géographique de l'huile d'olive. Les approches les plus fiables qui ont démontré des résultats prometteurs pour la traçabilité géographique des produits alimentaires étaient basées sur l'empreinte multi-élémentaire et isotopique. Néanmoins, éléments traces, initialement présents à des concentrations faibles à très faibles dans l'huile d'olive, sont dissous dans une matrice lipidique complexe et donc l'introduction des échantillons dans les instruments basés sur le plasma et les mesures précises des composants chimiques sont difficiles. Cette étude présente une approche analytique fiable basée sur une information géographique tridimensionnelle : (1) la composition minérale du sol à travers l'analyse des éléments traces; (2) le contexte géologique par l'analyse de la composition isotopique du Sr; et (3) le contexte pédo-climatique à travers la détermination des isotopes stables du carbone dans les huiles d'olive. Tout d'abord, les éléments traces ont été quantifiés dans des huiles d'olive de Tunisie, d'Espagne et de France avec une grande précision et exactitude par ICP-MS quadripolaire suivant une procédure analytique optimisée. Les concentrations élémentaires combinées à la chimiométrie ont permis de classer les huiles d'olive en fonction de leur provenance géographique. Par la suite, une méthode innovante a été développée et appliquée avec succès pour l'extraction quantitative du Sr à partir de l'huile d'olive et la mesure précise du rapport isotopique 87Sr/86Sr par MC-ICP-MS. La conservation des rapports isotopiques 87Sr/86Sr pendant le transfert du Sr du sol à la plante et pendant l'extraction de l'huile d'olive a été démontrée. Les résultats ont été corrélés avec les caractéristiques géologiques des roches mères et ont ainsi mis en évidence que la composition isotopique Sr de l'huile d'olive peut être utilisée comme un outil fiable pour identifier la provenance géographique de l'huile d'olive. Dans la dernière partie du manuscrit, les isotopes stables du carbone ont été déterminés dans les huiles d'olive par IRMS et ont permis de retracer les processus physiologiques de l'olivier en fonction des caractéristiques environnementales spécifiques. Chacune des trois approches mono-paramètre étudiées a fourni des informations géographiques fiables mais limitées. C'est pourquoi elles ont été combinées avec la chimiométrie afin d'établir un outil d'authentification géographique avancé capable de faire face aux pratiques frauduleuses les plus sophistiquées<br>The globalization of the food industry has raised consumer interest in the geographical origin and the quality of food products. The global increase in food production and consumption, however, has led to fraudulent practices spreading. It threatens both the health of consumers and the economic balance of the food industry, which suffers huge financial loss every year. Olive oil is one of the most adulterated food products. As a result, a large array of analytical strategies was proposed for the geographical authentication of olive oil. The most reliable approaches that have demonstrated promising results for the geographical traceability of food products were based on the multi-elemental and isotopic fingerprinting. Nevertheless, trace elements, initially found at low to critically low concentrations in olive oil, are dissolved in a complex lipid matrix and thus the samples introduction in plasma-based instruments and the precise measurements of chemical components are challenging. This study presents a reliable analytical approach based on a three dimensional geographic information: (1) the mineral composition of the soil through the analysis of trace elements; (2) the geological background through the analysis of Sr isotopic composition; and (3) the pedo-climatic context through the determination of stable isotopes of carbon in olive oils. First, the trace elements were quantified in olive oils from Tunisia, Spain and France with high precision and accuracy by quadrupole ICP-MS following an optimized analytical procedure. The elemental concentrations combined with chemometrics allowed to classify olive oils according to their geographical provenance. Subsequently, an innovative method was developed and successfully applied for the quantitative extraction of Sr from olive oil matrix and accurate measurement of 87Sr/86Sr isotopic ratio by MC-ICP-MS. The conservation of 87Sr/86Sr isotopic ratios during the transfer of Sr from the soil to the plant and during olive oil extraction was demonstrated. The results were correlated with the geological characteristics of the bedrocks and thus highlighted that Sr isotopic composition of olive oil can be used as a reliable tool for fingerprinting olive oil geographic provenance. In last part of the manuscript, the stable isotopes of carbon were determined in olive oils by IRMS and allowed to trace the physiological processes of the olive tree to specific environmental characteristics. Each of the three studied single-parameter approaches provided reliable but limited geographic information. Therefore, they were combined together with chemometrics in order to establish an advanced geographical authentication tool able to overcome the most sophisticated fraudulent practices
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Klein, Sara, and Sara Klein. "Einfluss der variierenden Nährstoffzusammensetzung einer stärkebetonten Ration auf die Glucose- und Insulinreaktion beim gesunden Pferd." Doctoral thesis, Universitätsbibliothek Leipzig, 2010. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-38409.
Full textAbstract:
Die Abdeckung des Energiebedarfs ist insbesondere bei Sport- und Zuchtpferden mit einer Aufnahme hoher Stärkemengen gekoppelt. Daraus können jedoch sowohl fermentative Störungen, bedingt durch das Abfluten von Stärke in den Dickdarm, als auch metabolische Veränderungen resultieren, wobei letztere insbesondere in Form von gesteigerten Glucose- und Insulinreaktionen zum Ausdruck kommen und nicht zuletzt in der Entstehung einer Insulinresistenz münden können. In der vorliegenden Arbeit sollte der Einfluss verschiedener Nährstoffe bzw. Futtermittel in Kombination mit der Aufnahme einer stärkereichen Mahlzeit auf die Glucose- und Insulinreaktion bei gesunden Pferden überprüft werden. Für die Versuche standen insgesamt zwölf Wallache (Alter: 6 ± 4 Jahre, Gewicht: 552 ± 84 kg) zur Verfügung. Die Untersuchungen unterteilten sich in drei Fragestellungen, bei denen die jeweiligen Futtermittel randomisiert oder blockweise angeboten wurden. Als stärkereiche Mahlzeit wurde einmal täglich morgens Bruchmais in einer Dosierung von 2 g Stärke / kg KM verfüttert. Im ersten Versuchsabschnitt erhielten die Pferde verschiedene Heuzuteilungsformen (ad libitum oder restriktiv (0,6 kg / 100 kg KM)) in der Nacht vor Bruchmaisaufnahme sowie nach der Fütterung des Bruchmaises. Im zweiten Versuch wurde der Bruchmais in Kombination mit extrahierten Rohfaserquellen (0,2 g / kg KM Cellulose / Hemicellulose oder 0,1 g / kg KM Apfelpektin) oder 0,2 g Rohprotein / kg KM (in Form von Maiskleber) verfüttert. Im dritten Versuchsabschnitt erfolgte die Zulage von 0,2 ml Soja- oder Fischöl / kg KM zum Bruchmais. Je nach Fragestellung durchliefen die Pferde eine acht- bis elftägige Adaptationsphase, nach welcher sich ein- bis zweitägige Blutprobenentnahmetage anschlossen. Hierbei wurde den Pferden über einen Venenverweilkatheter bis 510 Minuten ppr. jeweils in halbstündigen Abständen Blut entnommen. Im Plasma wurden die Blutparameter Glucose (GOD-Methode) und Insulin (Radioimmunoassay) bestimmt. Es konnte gezeigt werden, dass die Zufuhr von Rohfaser in Form von Heu vor und nach Aufnahme einer stärkereichen Ration keinen wesentlichen Einfluss auf die Glucosereaktion hatte. Hierbei wurden die Glucosekonzentrationen nach zwölfstündiger Nüchterung durch die Heufütterung während der Blutentnahme nicht beeinflusst (AUCHeu restriktiv nachts, Heu restriktiv tags 132 ± 72,5 mmol x min / l, AUCHeu restriktiv nachts, Heu ad libitum tags 144 ± 114 mmol x min / l, Behandlung p > 0,05). Die Heuaufnahme während der Blutentnahme führte zu signifikant höheren Glucosekonzentrationen (Behandlung p = 0,02) wenn die Pferde vor der Bruchmaisaufnahme ad libitum Zugang zu Heu hatten (Heu ad libitum nachts, Heu ad libitum tags). Die Flächen unter den Glucosekurven wiesen jedoch keine signifikanten Unterschiede zwischen den Behandlungen auf (AUCHeu ad libitum nachts, Heu restriktiv tags 89,5 ± 50,5 mmol x min / l, AUCHeu ad libitum nachts, Heu ad libitum tags 113 ± 62,7 mmol x min / l, Behandlung p > 0,05). Die Heufütterung während der Blutentnahme ließ nach zwölfstündiger Nüchterung signifikant höhere Insulinkonzentrationen (AUCHeu restriktiv nachts, Heu ad libitum tags 5996 ± 4460 µU x min / ml) erkennen als ohne Heufütterung (AUCHeu restriktiv nachts, Heu restriktiv tags 1626 ± 1040 µU x min / ml, Behandlung p = 0,02). Die Pferde zeigten weiterhin signifikant höhere Insulinwerte, wenn nach der Fütterung des Bruchmaises Heu ad libitum aufgenommen werden konnte (AUCHeu ad libitum nachts, Heu restriktiv tags 1275 ± 845 µU x min / ml, AUCHeu ad libitum nachts, Heu ad libitum tags 3701 ± 2163 µU x min / ml, Behandlung p = 0,04). Die Zugabe extrahierter Rohfaserquellen wie Cellulose / Hemicellulose sowie Pektin zu einer definierten Maisaufnahme zeigte keinen signifikanten Einfluss auf die Glucose- (AUCBruchmais 230 ± 163 mmol x min / l, AUCCellulose / Hemicellulose 259 ± 215 mmol x min / l, AUCPektin 274 ± 106 mmol x min / l, Behandlung p > 0,05) und Insulinreaktion (AUCBruchmais 8885 ± 4024 µU x min / ml, AUCCellulose / Hemicellulose 8767 µU x min / ml, AUCPektin 10657 µU x min / ml, Behandlung p > 0,05). Durch die additive Supplementierung von Sojaöl- und Fischöl zu einer stärkehaltigen Mahlzeit ließen sich keine signifikanten Unterschiede in der Glucose- (AUCSojaöl 268 mmol x min / l, AUCFischöl 234 mmol x min / l, AUCBruchmais 257 ± 113 mmol x min / l) und Insulinreaktion (AUCSojaöl 4640 µU x min / ml, AUCFischöl 3653 µU x min / ml, AUCBruchmais 4703 ± 3365 µU x min / ml) im Vergleich zur isolierten Bruchmaisaufnahme erkennen. Die Ergänzung von Protein zu einer stärkehaltigen Mahlzeit zeigte sehr variable Reaktionen innerhalb der Einzelpferde, wobei zwei Pferde keine Reaktion und zwei Pferde erhöhte Insulinreaktionen zeigten. Unterschiede in den Glucosereaktionen wurden nicht beobachtet. Zusammenfassend ist hervorzuheben, dass die gewählten Fütterungskonzepte (Zulage extrahierter Faserquellen, Protein oder Fett) bei einer Stärkezufuhr von 2 g Stärke / kg KM keinen signifikanten Einfluss auf die Glucose- und Insulinreaktionen hatten. Dagegen führte die Fütterung von Heu ad libitum nach Aufnahme einer stärkereichen Ration zu erhöhten Insulinkonzentrationen. Um die Glucose- und Insulinreaktion nachhaltig abschwächen zu können, ist als effiziente Maßnahme eine Reduktion der aufgenommenen Stärkemenge pro Mahlzeit zu empfehlen, wohingegen die Zulage von Rohfaser und Fett bei standardisierter Stärkeaufnahme keine Abschwächung der postprandialen Glucose- und Insulinreaktion bewirkt<br>In order to meet horses’ requirements of work and exercise feeding high amounts of starch is common practice. However, a high intake of starch can increase the risk of either fermentative disorders due to an overload of starch in the hindgut, or of metabolic disorders leading to exaggerated blood glucose and insulin concentrations which possibly could induce insulin resistance. The aim of this study was to investigate the effects of different nutrients in combination with the intake of a starchy meal on blood glucose and insulin concentrations in healthy horses. Twelve geldings (age: 6 ± 4 years, body weight (BW): 552 ± 84 kg) were fed the respective diets either in a randomized order or in a block design. The experiment was divided into three feeding trials. In each trial, horses received cracked corn (2 g starch / kg BW) in the morning (0800 h). In the first trial horses were fed cracked corn and grass hay in four different orders (hay ad libitum or hay restrictive (0.6 kg / 100 kg BW)), in the night before and after the intake of cracked corn. In the second trial cracked corn was mixed with extracted diatary fibers (cellulose / hemicellulose (0.2 g / kg BW) or apple pectin (0.1 g / kg BW)) or with corn gluten (2 g crude protein / kg BW). In the third trial cracked corn was fed either in combination with soybean oil (0.2 ml / kg BW) or in combination with fish oil (0.2 ml / kg BW). Each feeding period consisted of eight to eleven days of acclimatization to the different diets followed by one or two blood collection days. Blood samples were taken via a venous catheter in half-hour intervals up to 510 minutes ppr. Plasma glucose concentrations were measured by a glucose oxidase assay, and insulin levels were determined using a radioimmunoassay. There was no influence of hay feeding during blood collection after a 12 h overnight fast on plasma glucose concentrations (AUChay restriktive night, hay restriktive day 132 ± 72.5 mmol x min / l, AUChay restriktive night, hay ad libitum day 144 ± 114 mmol x min / l, treatment p > 0.05). In contrast, hay feeding during the blood collection period led to significant higher plasma glucose concentrations (treatment p = 0.02) when horses had ad libitum access to hay in the night before the intake of cracked corn. There was no significant difference in the AUC (AUChay ad libitum night, hay restriktive day 89.5 ± 50.5 mmol x min / l, AUChay ad libitum night, hay ad libitum day 113 ± 62.7 mmol x min / l, treatment p > 0.05). Furthermore, horses which were fed hay ad libitum after the intake of cracked corn demonstrated significant higher insulin concentrations (AUChay restriktive night, hay ad libitum day 5996 ± 4460 µU x min / ml) than horses without hay feeding (AUChay restriktive night, hay restriktive day 1626 ± 1040 µU x min / ml, treatment p = 0.02). In case of ad libitum hay feeding during the night significant higher insulin concentrations were found in horses which had ad libitum access to hay after intake of cracked corn when compared to horses without hay feeding during blood collection (AUChay ad libitum night, hay restriktive day 1275 ± 845 µU x min / ml, AUChay ad libitum night, hay ad libitum day 3701 ± 2163 µU x min / ml, treatment p = 0.04). The addition of extracted cellulose / hemicellulose and extracted apple pectin did not change the glycaemic (AUCcracked corn 230 ± 163 mmol x min / l, AUCcellulose / hemicellulose 259 ± 215 mmol x min / l, AUCpectin 274 ± 106 mmol x min / l, treatment p > 0,05) and insulinaemic responses (AUCcracked corn 8885 ± 4024 µU x min / ml, AUCcellulose / hemicellulose 8767 µU x min / ml, AUCpectin 10657 µU x min / ml, treatment p > 0.05) in comparison to isolated intake of cracked corn. There were no differences in postprandial glucose (AUCsoybean oil 268 mmol x min / l, AUCfish oil 234 mmol x min / l, AUCcracked corn 257 ± 113 mmol x min / l, treatment p > 0,05) and insulin responses (AUCsoybean oil 4640 µU x min / ml, AUCfish oil 3653 µU x min / ml, AUCcracked corn 4703 ± 3365 µU x min / ml, treatment p > 0.05) between feeding either cracked corn alone or in combination with soybean oil or fish oil. Protein supplementation of a starchy meal resulted in highly individual insulin responses. Two horses showed higher insulin concentrations after addition of protein to the corn meal, whereas two horses showed no reaction to the respective diet. There were no differences in the glycaemic responses. In conclusion, the results demonstrated no influence of the applied feeding strategies including supplementation of a starchy meal (2 g / kg BW) by extracted dietary fibers, protein or fat on postprandial glucose and insulin responses. In contrast, hay feeding increased the plasma insulin concentrations after the intake of cracked corn. To attenuate the glycaemic and insulinaemic responses in the horse efficiently, a reduction of starch intake per meal to quantities below 1 g starch per kg BW and meal is recommended, whereas feeding strategies like the addition of fiber or fat to a standardised starch intake do not improve glucose metabolism in healthy horses
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Ross, Trinette Noel. "Evaluation of bone biochemical markers and inflammatory markers in yearlings fed varying ratios of omega-6 and omega-3 polyunsaturated fatty acids." [College Station, Tex. : Texas A&M University, 2006. http://hdl.handle.net/1969.1/ETD-TAMU-1036.
Full text
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Oliynyk, Mariya. "Financial analysis and comparison between two oil gigants Exxonmobil and Chevron." Master's thesis, Vysoká škola ekonomická v Praze, 2014. http://www.nusl.cz/ntk/nusl-193246.
Full textAbstract:
This work provides financial analysis and comparison of two oil companies: Chevron and ExxonMobil, with bigger accent on practise rather than theory. It could be divided into two main parts: history and financial analysis itself. In the first part history of both oil giant was provided, from the beginning until nowadays. Second part was divided into chapters: single-criterion analysis and multiple-criteria comparison. In single-criterion analysis I applied horizontal and vertical analysis on balance sheet, income statements and cash flows statements of both companies. Then analysis of financial ratios was done: profitability, liquidity, debt, asset management, capital market and work productivity. Moreover, economic value added was calculated. In multiple-criteria comparison method of a simple division and prosperous (Tamari) and bankruptcy models (Z-score and Beerman) were calculated. In conclusion the main and the most significant results and comparison and comments were provided.
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Karakurt, Necdet. "Estimating attenuation properties of bentonite layer in Cut Bank oil field, Glacier County, Montana." Texas A&M University, 2005. http://hdl.handle.net/1969.1/3282.
Full textAbstract:
Acquisition and interpretation of 3-D seismic data led DeAngelo and Hardage (2001)
to describe the channel system in the south central Cut Bank area in Glacier County,
Montana. The presence of a low velocity layer called Bentonite was also discovered
in the area with the help of well-logs. Bentonite is a volcanic ash, which lies on both
sides of the channel system and is absent within the channel. DeAngelo and Hardage
(2001) shot a vertical seismic profiling (VSP) survey at well # 54-8 to analyze the
formation structure in depth, since seismic signals around the reservoir area were
unclear in the 3-D survey.
This research attempts to estimate the attenuation properties of the Bentonite
layer in the Cut Bank oil field. VSP data is processed for velocity information and
estimation of seismic Q using the spectral ratios method (SRM). The SRM theoretically
assumes that the propagating signal is a plane seismic wave traveling vertically
from one point to another in a homogeneous model. The amplitudes at the start
and end points are known and relate to each other with the attenuation coefficient in
a frequency range. The relation between the seismic amplitudes at z distance from
each other can be expressed as a linear function of frequency after a few modifications.
SRM uses the linearity of the logarithmic ratio of the seismic amplitudes over
a frequency range. In theory, ratios plotted against a frequency range must produce
a flat line. However, in practice, the logarithmic ratios are expected to draw an approximate
line (curve), where some of the data points deviate from the origin of the
line. Thus fitting a line to the ratios curve and calculating the slope of this curve are
necessary. Slope of the curve relates to the seismic attenuation coefficient and further
to the seismic Q.
The SRM results suggest that Bentonite may have a Q value as low as 5. This
highly attenuative and thin (20 to 40 feet throughout the south central Cut Bank
Unit) layer alters seismic signals propagating through it. A thorough analysis of
the amplitude spectra suggests that seismic signals dramatically lose their energy
when they pass through Bentonite. Low energy content of the signals below the Bentonite layer highlights that the recovery of the seismic energy is less likely despite
the presence of multiples, which are known to affect the seismic signals constructively.
Therefore, separation of reflected events is a greater challenge for the thin reservoir
sand units lying underneath the Bentonite layer. Thus the Bentonite layer in the
Cut Bank oil field has to be taken seriously and data processing should be done
accordingly for better accuracy.
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Миндюк, В. Д. "Розроблення методу оцінки якісних змін матеріалів нафтогазового обладнання за комплексом фізичних характеристик". Thesis, Івано-Франківський національний технічний університет нафти і газу, 2014. http://elar.nung.edu.ua/handle/123456789/4680.
Full textAbstract:
Досліджено особливості мікроструктурих змін матеріалів металоконструкцій в процесі експлуатації. Встановлено основні фізичні параметри, що зазнають змін внаслідок змін в мікроструктурі. Проаналізовано сучасний стан методів та засобів проведення структуроскопії. Проведено дослідження якісних змін фізичних параметрів матеріалів в залежності від зміни мікроструктури. Проведено дослідження щодо для одержання основних параметрів мікроструктури з використанням нових методів обробки металографічних зображень, а також фізичних характеристик матеріалу з використанням методів і засобів, що грунтуються на різних фізичних принципах. Встановлений оптимальний комплекс фізичних параметрів, що найкраще корелюють з вибраними параметрами мікроструктури. З використанням алгоритмів штучних нейронних мереж одержані функції апроксимації параметрів мікроструктури, а саме співвідношення перліт/ферит та середній діаметр зірна, від твердості, коерцитивної сили та магнітного індукційного параметру, що характеризує частоту електромагнітних коливань індуктивного перетворювача. Розроблено методологію оцінювання якості матеріалу шляхом визначення параметрів мікроструктури за комплексом фізичних характеристик для подальшого їх використання для розрахунків механічних характеристик матеріалів та оцінювання ступеню деградації матеріалу.<br>Диссертация посвящена вопросу оценки качества материалов нефтегазового оборудования путем оценки микроструктурных изменений за комплексом физических характеристик. Анализ процессов деградации структуры разных типов сталей и ее последствий показал, что показателями деградации структуры металла, которые стоит поддавать диагностике, есть изменение размеров и ориентации зерен отдельных структурных фаз со временем, морфологическое изменение отдельных фаз и изменение их соотношения в структуре, что значительно влияют на изменение отдельных физических свойств материалов, а, особенно, - структурно чувствительных параметров, выделение вторичных фазовых составляющих (например, карбидов легирующих элементов или низкотемпературных модификаций металла из высокотемпературной) из основных фаз и распределение их по границах зерен, группирования в отдельные зоны. Во втором разделе проведено качественное изучение процессов изменения физических структуруо чувствительных свойств ферритных сталей. На основе результатов изучения особенностей изменения магнитных свойств, электрического сопротивления, теплопроводной характеристику и твердости, избранные параметры выбраны для дальнейших исследований относительно определения корреляции между этими параметрами и параметрами микроструктуры. Третий раздел содержит методику и результаты экспериментальных исследований по установлению зависимости избранных информативных физических параметров от параметров микроструктуры отобранных образцов разных марок сталей. Определены зависимости отдельных физических свойств сплавов от характеристик микроструктуры - соотношения перлит/феррит и среднего диаметра зерна, а также определен оптимальный комплекс физических свойств с наилучшей корреляцией их с параметрами микроструктуры. Использование алгоритмов нейронных сетей позволило получить зависимости микроструктурных характеристик от комплекса физических свойств в аналитическом виде. Четвертый раздел посвящен разработке методологии оценки качества материала путем определения параметров микроструктуры за комплексом физических характеристик для дальнейшего их использования для расчетов механических характеристик материалов и оценки степени деградации материала, которая прошла успешную промышленную апробацию в условиях РВУ «Львовавтогаз» и НПФ «Зонд» и внедрена в нормативных документах нефтегазовой отрасли.<br>Dissertation is devoted to assessing the quality of oil and gas equipment materials by evaluating complex microstructural changes with physical characteristics. The features of the microstructural changes of metal materials during operation are investigated. The basic physical properties that are experiencing changes due to changes in the microstructure are identified. The current state of methods and means of structurescopy are analized. The investigation of qualitative changes in the physical parameters of materials depending on the change of the microstructure are studied. The main parameters of the microstructure with using new methods of metallographic image processing were obtained, as well as the physical characteristics of the material using the methods and tools that are based on different physical principles were measured. The optimal set of physical parameters that best correlated with the selected parameters of the microstructure is established. Approximation functions of microstructure parameters such as a ratio of pearlite/ferrite and the average grain diameter with the hardness, coercitiviy, magnetic induction parameter which characterizes the oscillation frequency of the electromagnetic inductive transducer are obtained by using artificial neural networks algorithm. A methodology for assessing the quality of the material by determining the microstructure parameters with the complex of physical characteristics for further use in the calculation of materials mechanical characteristics and material degradation assessment is developed.
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GABARRÓ, FERNÁNDEZ ADRIANA. "“INFLUENCE OF SUNFLOWER OIL AND Schizochytrium microalgae ON RUMINAL METHANE AND CARBON DIOXIDE EMISSIONS OF TOTAL MIXED RATION IN STEERS." Tesis de Licenciatura, Universidad Autónoma del Estado de México, 2017. http://hdl.handle.net/20.500.11799/67716.
Full textAbstract:
La producción ganadera contribuye con alrededor del 18% de metano (CH⁴) y el 9%
de las emisiones de dióxido de carbono (CO²) de producción, que se han implicado
en causar el cambio climático. El metano, CO², hidrógeno (H²) son los principales
gases producidos durante la fermentación ruminal, lo que provoca una pérdida de 2
a 12% de la energía de la dieta de los rumiantes (Johnson y Johnson, 1995).
Mejorar la utilización de piensos y el rendimiento animal es el principal objetivo de
los nutricionistas; Sin embargo, deben considerarse las obligaciones sociales y
ambientales para reducir las emisiones de gases de efecto invernadero (GEI). Se
han utilizado estrategias nutricionales incluyendo levadura (Elghandour et al., 2017),
sal de ácidos orgánicos (Elghandour et al., 2016), enzimas exógenas y aceites
esenciales para controlar la producción de metano ruminal de los rumiantes (Kholif
et al., 2017B).
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Garcia-Blanco, Susana. "Testing the resource-ration theory as a framework supporting a bioremediation strategy for clean-up of crude oil-contaminated environments." Cincinnati, Ohio : University of Cincinnati, 2004. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=ucin1098275222.
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Johnston, Jennifer Lynn Atkinson Samuel F. "Home range analysis of rehabilitated and released great horned owls (Bubo virginianus) in Denton County, Texas, through radio telemetry." [Denton, Tex.] : University of North Texas, 2007. http://digital.library.unt.edu/permalink/meta-dc-5159.
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Aboglila, Salem Abdulghni-O. "Organic and isotopic geochemistry of source-rocks and crude oils from the East Sirte Basin (Libya)." Thesis, Curtin University, 2010. http://hdl.handle.net/20.500.11937/2118.
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The Sirte Basin is a major oil producing area in Libya, but the understanding of the processes that have led to the petroleum accumulation is still limited. Exploration studies of this area have shown that the oils are mixtures of several charges and may be from different source rocks. The main aims of this thesis are to improve our understanding of the petroleum accumulation history in the East Sirte Basin.Biomarker ratios, together with stable carbon (δ[superscript]1[superscript]3C) and hydrogen (δD) isotopic compositions of individual hydrocarbons have been applied to 24 crude oils from the East Sirte Basin to delineate their sources and respective thermal maturities. The crude oil samples are divided into two main families (A and B) based on differences in source inputs and thermal maturity. Using source-specific biomarker parameters based on pristane/phytane (Pr/Ph), hopane/sterane ratios, dibenzothiophene (DBT) / phenanthrene (P), Pr/n-C[subscript]1[subscript]7, Ph/n-C[subscript]l[subscript]8 and the distribution of tricyclic and tetracyclic terpanes, family B oils are ascribed a marine source rock deposited under sub-oxic conditions, whereas family A oils have a more terrestrial source affinity. This source classification is supported by the stable carbon isotopic compositions (δ[superscript]1[superscript]3C) of the n-alkanes. Family A oils were found to be more mature based on differences between the stable hydrogen isotopic compositions (δD) of Pr and Ph and the n-alkanes, as well as the δ[superscript]1[superscript]3C values of n-alkanes.Within a complex geological setting several potential source rocks have been recognised, ranging in age from Precambrian to Eocene. Biomarker ratios, together with δ[superscript]1[superscript]3C and δD of individual hydrocarbons have been applied to 21 source rock extracts from the East Sirte Basin to establish their respective thermal maturity and palaeoenvironmental conditions of deposition. Rock Eval pyrolysis data obtained from the source rocks of the Sirte, Tagrifet, Rakb, Rachmat, Bahi and Nubian Formations show that the organic matter (OM) is mainly dominated by a Type II/III kerogen. Vitrinite reflectance (% R[subscript]o range: 0.46 – 1.38) data support variations in thermal maturity and indicate mature to post mature rocks of Sirte and Rachmat Formations and early to mid stage maturities for the rest of the formations. The Sirte Formation in the studied area was found to be relatively more thermally mature than the Tagrifet, Rakb, Rachmat, Bahi, and Nubian Formations, reflected by δD of Pr and Ph (less depleted in D).Various unusual steroid biomarkers in the oils and East Sirte source-rocks were identified by gas chromatography- mass spectrometry (GC-MS) and GC- metastable reaction monitoring (MRM) mass spectrometry. These included 24-norcholestanes, dinosteranes, 4α-methyl-24-ethylcholestanes and triaromatic steroids. Diatoms, dinoflagellates and/or their direct ancestors are the proposed sources of these components. These biomarker parameters have been used to establish a Mesozoic oil-source correlation of the East Sirte Basin. This is consistent with the presence of dinoflagellate cysts in the Nubian Formation of Lower Cretaceous age.
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Walker, Devin Mason. "Catalytic Tri-reforming of Biomass-Derived Syngas to Produce Desired H2:CO Ratios for Fuel Applications." Scholar Commons, 2012. http://scholarcommons.usf.edu/etd/4250.
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This study focuses on upgrading biomass derived syngas for the synthesis of liquid fuels using Fischer-Tropsch synthesis (FTS). The process includes novel gasification of biomass via a tri-reforming process which involves a synergetic combination of CO2 reforming, steam reforming, and partial oxidation of methane. Typical biomass-derived syngas H2:CO is 1:1 and contains tars that deactivate FT catalyst. This innovation allows for cost-effective one-step production of syngas in the required H2:CO of 2:1 with reduction of tars for use in the FTS. To maximize the performance of the tri-reforming catalyst, an attempt to control oxygen mobility, thermal stability, dispersion of metal, resistance to coke formation, and strength of metal interaction with support is investigated by varying catalyst synthesis parameters. These synthesis variables include Ce and Zr mixed oxide support ratios, amount Mg and Ni loading, and the preparation of the catalyst. Reaction conditions were also varied to determine the influences reaction temperature, gas composition, and GHSV have on the catalyst performance. Testing under controlled reaction conditions and the use of several catalyst characterization techniques (BET, XRD, TPR, XAFS, SEM-EDS, XPS) were employed to better explain the effects of the synthesis parameters. Applications of the resulting data were used to design proof of concept solar powered BTL plant. This paper highlights the performance of the tri-reforming catalyst under various reaction conditions and explains results using catalyst characterization.
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Johnston, Jennifer Lynn. "Home range analysis of rehabilitated and released great horned owls (Bubo virginianus) in Denton County, Texas, through radio telemetry." Thesis, University of North Texas, 2007. https://digital.library.unt.edu/ark:/67531/metadc5159/.
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Raptor rehabilitation has become commonplace globally, yet studies on the survival and adaptation of great horned owls (Bubo virginianus) after release has been neglected to an appreciable extent. The primary objective of this study is to provide quantitative data on the success of rehabilitated and released great horned owls in the North Texas region. Owls (N=12) were rehabilitated and released onto the Ray Roberts Greenbelt Corridor in Denton County, Texas, and monitored using radio telemetry to evaluate home range (November 2002 - February 2005). With approximately 75% of the birds released for this study surviving until transmitter battery failure, it is believed that the rehabilitation process was successful for these birds.
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Borsari, Flávia Neme [UNESP]. "Efeito da aplicação da menbrana de látex natural e do extrato da pele de rã (Lithobates catesbiana) (Shaw, 1802), em feridas cirurgicas em Ratos Wistar." Universidade Estadual Paulista (UNESP), 2008. http://hdl.handle.net/11449/89058.
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borsari_fn_me_jabo.pdf: 1735034 bytes, checksum: e60f1d1b95155d0c2bf8045c4a7df703 (MD5)<br>Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)<br>Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)<br>Neste estudo, implantou-se biomembrana de látex natural isolada e em conjunto com o extrato da pele de rã em feridas cutâneas (2,0 X 2,0 cm) na região dorsal de ratos com o intuito de se avaliar o processo de reparação tecidual no que se refere à biocompatibilidade, capacidade de reparação e possíveis complicações. Utilizou-se 60 ratos da linhagem Wistar, adultos, machos inteiros, divididos em grupos experimentais: grupo controle (GC), membrana de látex (GM), grupo óleo de rã (GO) e grupo membrana de látex e óleo de rã (GMO), cada um com 15 animais. Aos três, cinco, sete, 14 e 21 dias de pós-operatório, os animais foram eutanasiados mediante o emprego de uma dose elevada de tiopental sódico para avaliações macroscópicas, histológicas e histomorfométricas da região da lesão. No terceiro dia pós-operatório, em todos os grupos, as lesões apresentavam-se hiperemicas e não edematosas. No grupo controle havia inicio da presença de crostas e de tecido de granulação. Observou-se a presença de exudato amarelado e tecido de granulação nas lesões referentes aos grupos óleo e membrana + óleo, neste último, em menor quantidade. No quinto dia pósoperatório as lesões, de todos os grupos, apresentaram-se com as margens retraídas; no GC as crostas cobriram toda a lesão; no GM observou-se a presença de tecido de granulação nas margens da ferida; no GO verificou-se a presença de algumas crostas e aspecto hiperêmico com tecido de granulação, no grupo membrana + óleo o tecido de granulação foi intenso No sétimo dia de pósoperatório, verificou-se que a retração progrediu nas margens das lesões, além da presença de granulação vermelho brilhante e crostas, principalmente nos grupos GC, GM e GO Após este período houve espessamento das crostas e retração contínua, ainda com presença de tecido de granulação.<br>In this study of the biomembrane of the natural latex and extract of the skin frog, isolated and together, where implanted utilized to replace a cutaneous rats in the dorsal region of the mice, with purpose of evaluation of the tissue repair process in regard of its biocompatility, scar formation ability and possible complication. Sixty Wistar mices adult and entire males were divided in four experimental groups: control group (GC), membrane of the latex group (GM), oil of the frog group (GO) and group membrane of latex with oil of the frog group (GMO), each one with 15 animals. The animals were euthanized at three, five, seven, 14 and 21 days of post operative, by use of an elevated dosage of sodium tiopental, followed by macroscopic, microscopic and stereologic evaluations of the area of the lesion. Macroscopically, in the third post operative day, in all of the groups, the lesions were hiperemic but were not edematous. In the control group there were present crusts and of granulation tissue. It was observed the presence of yellowish exudato and granulation tissue in the lesions to the groups oil and membrane with oil, in this last one, in smaller amount. In the 5th post operative day the lesions, of all the groups, came with the reserved margins; in GC the crusts covered the whole lesion; in GM the presence of granulation tissue was observed in the margins of the wound; in GO it verified the presence of some crusts and hiperemic aspect with tissue granulation. In the group membrane with the oil the granulation tissue was intense. In the 7 th day of post operative, it was verified that the retraction progressed in the margins of the lesions, besides the brilliant red granulation presence and crusts, mainly in the groups GC, GM and GO After this period there was thickening of the crusts and continuous retraction, still with the presence of granulation fabric.
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Costa, Carlos Alberto Soares da. "Impacto da dieta hiperlipídica contendo óleo de canola ou de soja no desenvolvimento da adiposidade abdominal e estrutura óssea." Universidade do Estado do Rio de Janeiro, 2012. http://www.bdtd.uerj.br/tde_busca/arquivo.php?codArquivo=4615.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior<br>A baixa relação de ômega-6/ômega-3 esta relacionada com propriedades benéficas para a saúde óssea. No entanto, a dieta rica nestes compostos pode levar a obesidade. Adipócitos e osteoblastos derivam de células progenitoras comuns, e o consumo de óleo de canola pode ter ação adipogênica e osteogênica. Nosso objetivo foi avaliar a adiposidade abdominal, insulina e estrutura óssea em ratos tratados com dieta contendo baixa relação ômega-6/ômega-3, proveniente do óleo de canola. Após desmame, os ratos foram divididos em grupos alimentados com dieta normocalórica: Controle (S) e experimental (C), contendo 7ml/100g de óleo de soja ou de canola e grupos tratados com dieta rica em lipídios: Controle (7S) ou hiperlipídico contendo 19ml/100g de óleo de soja (19S) ou de canola (19C), até completarem 60 dias de idade. Os dados foram significativos com P<0,05. No primeiro modelo, o grupo C apresentou redução de: Massa e área do adipócito intra-abdominal; Colesterol; Insulina; Densidade mineral (DMO) e massa óssea total e na coluna vertebral; Massa do fêmur; Espessura da diáfise; DMO do fêmur e das vértebras lombares e radiodensidade da cabeça do fêmur. No segundo modelo, os grupos 19S e 19C apresentaram maior ingestão calórica, densidade corporal, massa de gordura intra-abdominal, e maior massa e comprimento do fêmur e da coluna lombar. O grupo 19S apresentou maior área e menor número de adipócitos da região retroperitoneal. Glicose e a insulina foram aumentadas no grupo 19C vs. 7S. A tomografia do fêmur revelou maior radiodensidade na região proximal e da coluna lombar, no grupo 19C. Sugerimos que a quantidade e o tipo de lipídio consumido, após o desmame, induzem não somente o desenvolvimento corporal e os depósitos de gordura, além de afetarem a resistência insulínica e a saúde óssea<br>The lower ratio of omega-6 to omega-3 polyunsaturated fatty acids is associated with healthy bone properties. However, fat diets can induce obesity. Adipocytes and osteoblasts derive from a common progenitor, and canola oil intake may have an adipogenic and osteogenic effect. Our objective was to evaluate the intra-abdominal adiposity, insulin and bone growth in rats fed diet containing lower ratio of omega-6 to omega-3, provided in canola oil. After weaning, rats were divided into groups fed with normocaloric diet: control (S) and experimental (C), containing 7ml/100g soybean or canola oil, respectively and groups fed with fat diet: control (7S) or fat diets containing 19ml/100g soybean oil (19S) or canola oil (19C), until they 60 days old. Differences were considered significant with P<0,05. In normocaloric diet model, C group showed a significant reduction in: Intra-abdominal fat mass; Area of adipocyte; Cholesterol; Insulin; Total body and spine bone mineral content and bone area; Femur mass; Width of the diaphysis; Femur and lumbar vertebrae bone mineral density and radiodensity of femoral head. To high-fat diet model, 19S and 19C groups showed higher energy intake, body density growth, intra-abdominal fat mass and higher femur mass and, lumbar vertebrae mass and length. 19S showed higher area and lower number of retroperitoneal adipocytes. Glucose and insulin were significantly increased in 19C compared to 7S group. Computed tomography of femur revealed higher radiodensity in proximal femoral epiphysis and lumbar vertebrae of 19C. We suggest that the amount and the source of fat used in the diet, after weaning, induce not only the body and fat depots growth, besides affecting the insulin resistance and the bone health
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Magdic, Matthew James. "Assessment of Soil Properties in Proximity to Abandoned Oil Wells usingRemote Sensing and Clay X-ray Analysis, Wood County, Ohio." Bowling Green State University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1462537679.
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De, Wet Martie. "The effect of colonic propionate and the acetate : propionate ratio on risk markers for cardiovascular disease in westernised African men." Thesis, Bloemfontein : Central University of Technology, Free State, 2009. http://hdl.handle.net/11462/30.
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Benites, Cibelem Iribarrem. "Destilado da desodorização do oleo de soja como suplemento de vitamina E." [s.n.], 2008. http://repositorio.unicamp.br/jspui/handle/REPOSIP/256263.
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Previous issue date: 2008<br>Resumo: A utilização de resíduos e subprodutos da indústria vem crescendo devido à necessidade de adequação das empresas às normas ambientais. Por outro lado, a substituição de insumos artificiais por produtos naturais nas áreas alimentícias, farmacêuticas e outras, vem ganhando forte destaque mundial. Estes fatos fomentam o estudo da utilização do Destilado da Desodorização do Óleo de Soja (DDOS) como suplemento de tocoferóis, que são compostos importantes na nutrição humana e animal, por apresentarem atividade vitamínica E e ação antioxidante natural. O DDOS é um subproduto oriundo do processo de refino do óleo de soja, que também é rico em ácidos graxos livres (AGL), esteróis e hidrocarbonetos, com potencialidade para extração de vitamina E; entretanto tem sido demonstrado que esta prática não é economicamente viável. Todavia, a utilização do DDOS na forma semi-refinada (neutra) torna-se uma alternativa para o enriquecimento de dietas animais e possivelmente humana. Com vistas a atingir tais objetivos, foi realizado um estudo do processo de neutralização variando o tipo de álcali, a concentração e o excesso adicionado do mesmo, além da temperatura do processo e do tempo de homogeneização. Após o estabelecimento das condições ótimas de processo, o DDOS foi neutralizado em maior quantidade para sua caracterização e como matéria-prima para a suplementação de ratos Wistar sadios recém-desmamados. Estes foram alimentados com dieta AIN-93G depletada em vitamina E e distribuídos conforme o período de suplementação oro-gástrica diária: 0 (n=7), 30 (n=42) e 60 dias (n=42), sendo estes últimos subdivididos pelo tipo de tratamento (7animais/grupo): Depletado (sem suplementação), Soja (óleo como placebo), Ephynal_ (vitamina E sintética), DDOS, DDOS 25 e DDOS 50 (respectivamente 150, 187,5 e 225 mg _- tocoferol/kg dieta). Através dos planejamentos experimentais, estabeleceram-se as condições ideais de neutralização (com maior redução de AGL, menor arraste de tocoferóis e maior rendimento), tendo como resultado: Na2CO3 (4,34N), temperatura de 45,8°C e tempo de homogeneização de 3¿20¿; com a neutralização, o teor de AGL passou de 53,4% para 6,1%, por isto foi neutralizado novamente para a suplementação dos ratos, resultando em 1,8% AGL e 11,0% de tocoferóis totais (TT). Na avaliação biológica, os resultados de crescimento e hemograma foram normais e, com 30 e 60 dias (30d e 60d) de suplementação, os tratamentos não apresentaram diferenças estatísticas na maioria dos aspectos (Tukey, p>0,05): triacilgliceróis séricos (118,8 mg/dL - 30d; 85,6 mg/dL - 60d); colesterol sérico (69,8 mg/dL - 30d; 65,5 mg/dL - 60d); transaminase oxaloacética (73,1 U/L - 30d; 81,3 U/L - 60d) e pirúvica (23,6 U/L - 30d; 28,3 U/L - 60d); bilirrubinas (0,2 mg/dL - 30d; 0,3 mg/dL - 60d). Assim, não houve danos hepáticos nem genotóxicos, pois a freqüência de micronúcleos estava dentro da taxa espontânea de mutação, i. e., freqüência admissível de mutação, sem dano para o organismo. Diferindo estatisticamente, o teor de lipídios hepáticos variou entre 6,5-8,5% e musculares 3,5-6,0%. A dosagem de isoprostanas com vistas a verificar o estado de oxidação não se mostrou adequada neste trabalho. O teor de MDA no tecido muscular não apresentou variação entre os grupos, aos 30d (1,6 µg MDA/g) e aos 60d (0,5 µg MDA/g) havendo uma redução. Para o tecido adiposo, aos 30d não houve diferença entre os grupos (1,9 µg MDA/g) e aos 60d houve aumento, sendo que os valores foram diferentes apenas matematicamente, sendo que com exceção do grupo Depletado, os demais não se diferenciaram (média aparente 2,7µg MDA/g). No tecido hepático, aos 30d houve uma diferença entre os grupos (média aparente 2,3 µg MDA/g), aos 60d houve um aumento no teor de MDA, sem diferença estatística entre os tratamentos (3,1 µg MDA/g). Quanto a distribuição de TT os grupos com DDOS tiveram desempenho intermediário dentre os tratamentos, sendo respectivamente para 30d e 60d: 7,3 µg/mL e 6,7 µg/mL no soro; 10,1 µg/g e 12,4 µg/g no fígado; 19,5 µg/g e 29,4 µg/g na gordura abdominal e 16,2 µg/g e 21,3 µg/g no músculo, com correlação positiva entre o teor de tocoferóis nos tecidos e o ingerido pelos animais. Os resultados mostraram que o DDOS não acarretou em alterações fisiológicas tóxicas nos animais, além de similaridade entre os efeitos dos tocoferóis naturais, presentes no DDOS, e os sintéticos, indicando o relevante potencial de utilização do produto como suplemento<br>Abstract: Increased use of industrial waste and byproducts fits the need of industry to comply with environmental rules. The substitution of natural products for artificial ingredients has gained worldwide attention in the food, pharmaceutical and other industries. These facts justify the study on the utilization of Soybean Oil Deodorizer Distillate (SODD) as tocopherol supplements. Tocopherol, which is physiologically active as vitamin E and a major natural antioxidant, is an especially important player in human and animal nutrition. SODD is a byproduct of the soybean oil refining process that is also rich in free fatty acids (FFA), sterols and hydrocarbons.
It has been demonstrated that the use of SODD for vitamin E extraction is not economically viable. However, SODD in the semi-refined form (neutral) can be an alternative for animal and possibly human diet enrichment. The objective of the present study was to evaluate the SODD neutralizing process varying the type, concentration, and excess of alkali, as well as the process temperature and time for homogenization. After establishment of the optimal process conditions, a greater amount of SODD was neutralized for raw-material characterization and for supplementation of recently weaned Wistar rats. The rats were fed with AIN-93G diet depleted of vitamin E and distributed following the daily orogastric supplementation period: 0 (n=7), 30 (n=42) and 60 (n=42) days. The 30 and 60 days were divided by the treatment type (7 animals/group): Depleted (without supplementation), Soy (oil as placebo), Ephynal_ (synthetic vitamin E), SODD, SODD 25 and SODD 50 (150, 187.5, and 225 mg _-tocopherol/kg diet, respectively). The optimal conditions for the neutralizing process, i.e., in order to obtain the greatest reduction in free fatty acid content, the lowest leaching of tocopherols and the greatest yield, were defined experimentally. The results were: Na2CO3 (4.34N), temperature of 45.8ºC and homogenization time 3¿20¿¿. The FFA content was reduced from 53.4% to 6.1% after neutralization, requiring a second step of neutralization, thus obtaining a free fatty acid content of 1.8% and 11.0% of total tocopherol (TT). The biological evaluation showed normal results for growth and hematology and with 30 and 60 days of supplementation (30d and 60d) the treatments did not show statistically significant differences (p>0.05) for serum triglycerides (118.8 mg/dL - 30d; 85.6 mg/dL - 60d); serum cholesterol (69.8 mg/dL- 30d; 65.5 mg/dL - 60d); glutamic-oxaloacetic transaminase (73.1 U/L - 30d; 81.3 U/L - 60d), glutamic-pyruvate (23.6 U/L - 30d; 28.3 U/L - 60d); and bilirubins (0.2 mg/dL - 30d; 0.3 mg/dL - 60d). No hepatic and genotoxic damage was observed, since the micronucleus frequency was in the spontaneous mutation rate, i.e., admissible mutation frequency without organism damage. Significant differences were observed for hepatic and muscle lipids levels varying from 6.5 to 8.5% and 3.5 to 6.0%, respectively. Isoprostanes dosage was found to be an inadequate criteria to verify oxidation state. The malonaldehyde content (MDA) in the muscular tissue was not different between groups at 30d (1.6 µg MDA/g) and 60d (0.5 µg MDA/g) despite a slight reduction. For adipose tissue, there was no difference between the groups for 30d (1.9 µg MDA/g) and for 60d these values was increased, and were statistically different; with the exception of Depleted group, the others were not different (apparent average of 2.7 µg MDA/g). In the liver, at 30d there was a difference between groups (apparent average of 2.3 µg MDA/g) but at 60d there was an increase in MDA content, without statistical difference between treatments (3.1 µg MDA/g). The TT distribution of groups showed intermediary performance among the treatments, being 7.3 µg/mL and 6.7 µg/mL in serum; 10.1 µg/g and 12.4 µg/g in the liver; 19.5 µg/g and 29.4 µg/g in abdominal fat; and 16.2 µg/g and 21.3 µg/g in the muscle, for 30 and 60 days, respectively. A positive correlation between tocopherol content in the tissues and tocopherol consumption by animals was observed. The results show that SODD did not cause physiological damage in animals. Different sources of vitamin E, natural (present in SODD) and synthetic tocopherols, yielded similar effects, suggesting the potential of using SODD as a supplement<br>Doutorado<br>Nutrição Experimental e Aplicada à Tecnologia de Alimentos<br>Doutor em Alimentos e Nutrição
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Gregório, Bianca Martins. "Suplementação materna com óleo de peixe e efeitos cardiovasculares na prole adulta de ratos submetidos à restrição protéica perinatal." Universidade do Estado do Rio de Janeiro, 2007. http://www.bdtd.uerj.br/tde_busca/arquivo.php?codArquivo=1584.
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Fêmeas Wistar foram alimentadas durante o período gestacional e a primeira metade da lactação (10 primeiros dias de lactação) com dieta normoprotéica (19 g proteína / Kg dieta) (grupo NP) e dieta restrita em proteínas (5 g proteína / Kg dieta) (grupo LP). Paralelamente a este esquema de alimentação, elas também receberam, diariamente, por gavagem, o óleo de peixe (Fo, rico em ácido graxo poliinsaturado- AGPi n-3). Os filhotes foram subdivididos em 4 grandes grupos: NP, NP-Fo, LP e LP-Fo, sendo acompanhados até os 6 meses de idade, data na qual ocorreu a eutanásia. No momento do sacrifício, o coração foi removido e devidamente preparado para a análise em microscopia de luz e estereologia. A partir do terceiro mês, os animais do grupo LP (ambos os gêneros) exibiram um aumento na pressão arterial sistólica (hipertensão moderada), mantendo esse comportamento até o final do experimento (6 meses de idade). No entanto, a suplementação materna com o Fo foi capaz de minimizar os efeitos da desnutrição sobre a pressão arterial. Não houve diferença significante no índice corporal entre os grupos de mães suplementadas com o Fo. O ventrículo esquerdo do grupo LP (ambos os sexos) demonstrou maior espessura quando comparado ao grupo NP (+25% nos machos, P=0,01, +22% nas fêmeas, P=0,001); entretanto, o grupo LP-Fo manifestou menor espessura quando comparado com o grupo LP (-23% nos machos, P=0,001, -12% nas fêmeas, P=0,02). Os machos do grupo LP apresentaram significativamente menor vascularização intramiocárdica quando correlacionado ao grupo NP (-50%, P=0,01), enquanto os machos do grupo LP-Fo exibiram um incremento de 89% na microcirculação, quando comparados ao grupo LP (P=0,004). Ambos os gêneros do grupo LP manifestaram maior quantidade de fibrose intersticial quando comparados ao grupo NP. Vale ressaltar que a suplementação materna de Fo foi benéfica apenas no grupo LP. Sendo assim, nossos dados sugerem claramente que a suplementação materna com Fo, durante o período perinatal, é capaz de prevenir o remodelamento cardíaco adverso e a hipertensão provocados pela restrição protéica materna in útero e na lactação, tornando-se assim uma opção não farmacológica viável para a prevenção e/ou redução dos danos ocasionados pela programação em humanos.<br>Female Wistar rats fed in gestation and first 10 lactation days with normal protein diet (19 g protein/kg diet) (NP group) or low-protein diet (5g protein/kg diet) (LP group), also received daily fish oil supplement (Fo, n-3 PUFA rich) during same period. Offspring put in groups NP, NP-Fo, LP, LP-Fo, until sacrifice at 6-mo-old when hearts removed, prepared for light microscopy and stereology. There was mild hypertension in both LP genders from 3- until 6 mo-old. Blood pressure affected by undernutrition was minimized by maternal Fo supplementation. In body index between groups there was no significant difference with maternal Fo supplementation. The left ventricle was thicker in both genders of LP groups compared to counterpart NP groups (+25% in male LP group, P=0.01, +22% in female LP group, P=0.001); however, less thick in LP-Fo groups compared to LP groups (-23% in male LP-Fo group, P=0.001, - 12% in female LP-Fo group, P=0.02). Male LP group offspring had significantly smaller intramyocardial microcirculation than NP group (-50%, P=0.01), while male LP-Fo group had 89% higher microcirculation than LP group (P=0.004). Both gender LP group offspring had significantly higher interstitial fibrosis compared with NP groups. The maternal Fo supplementation has beneficial effects in LP , but not in NP offspring. In conclusion, our data clearly indicate postnatal hypertension and collateral cardiovascular adverse remodeling, programmed by low-protein diet in utero and lactation was prevented by perinatal supplementation with fish oil, n-3 PUFA rich, providing a viable non-pharmacologic option for preventing and/or reducing adverse programming outcomes in human.
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Jacometo, Carolina Bespalhok. "Nutrigenômica: Efeito de dietas contendo ácido linolênico na expresão gênica de receptores nucleares relacionados ao metabolismo lipídico." Universidade Federal de Pelotas, 2012. http://repositorio.ufpel.edu.br/handle/ri/2618.
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Previous issue date: 2012-02-27<br>Dietary polyunsaturated fatty acids (PUFAs) are negative regulators of hepatic lipogenesis and their effects are at transcriptional levels. The essential fatty acids omega-3 and omega-6, consumed during pregnancy can benefit maternal and offspring health. The nuclear receptor peroxisome proliferator-activated receptor α (PPARα), when activated by PUFAs enhances lipolytic genes. Liver X receptor α (LXRα) and sterol regulatory element binding protein 1c (SREBP-1c) are nuclear receptors that enhance lipogenic genes, and are repressed by PUFAs. The present study aimed to investigate the effects of diets, rich in omega-3 or omega-6, consumed throughout three generations, on biochemical parameters and the expression level of some genes related to lipid metabolism. For this study we used adult Wistar/UFPel rats, composing the founding generation, females that received diet with flaxseed oil (OM group, n=18) or soybean oil (CTL group, n=18) during pregnancy. At F1 weaning, 48 females offspring were selected and allocated in three groups, females from OM group, that continued receiving diet with flaxseed oil (OM/OM group, n=16), females from OM group, that started to receive diet with soybean oil (OM/CTL group, n=16) and females from CTL group, that continued receiving diet with soybean oil (CTL/CTL group, n=16). At F2 weaning, 16 females offspring of each group were selected and continued receiving the same diets (OM/OM/OM group, OM/CTL/CTL group and CTL/CTL/CTL group). The females were evaluated in the pre-partum (19±1 days of pregnancy) and at postpartum period (21 days after parturition). The dietary fatty acid profile did not affect the diet daily intake and the pregnancy rate (P>0.05), however, dams that received the diet rich in omega-3 had heaviest offspring (P=0.01). Diets with higher omega-3 level decreased triglycerides serum levels, and maintained constant the non-esterified fatty acids (NEFA) levels (P=0.04), while the animals fed with high proportion of omega-6 had fluctuant NEFA levels, and an outstanding increase in the postpartum period of F2 generation (P=0.02). PPARα, RXRα, LXRα and SREBP-1c had been regulated by the diets throughout generations. In the pre-partum moment of F2 generation, the animals fed with high omega-3 had a lower expression of LXRα (P=0.01) indicating its effectiveness on inhibiting lipogenic action. Our results indicate that the PUFAs effect on the control of lipolysis and lipogenesis is cumulative throughout generations and the omega-3 exerts a better control.<br>Dietas contendo ácidos graxos poli-insaturados (AGPIs) exercem controle negativo sobre a lipogênese hepática e seus efeitos são observados ao nível transcricional. Os ácidos graxos essenciais ômega-3 e ômega-6, quando consumidos durante a gestação podem beneficiar a saúde materna e da prole. O receptor nuclear peroxisome proliferator-activated receptor α (PPARα), quando ativado pelos AGPIs favorecem a atividade de genes lipolíticos. O liver X receptor α (LXRα) e sterol regulatory element binding protein 1c (SREBP-1c) são receptors nucleares que ativam genes lipogênicos, e são reprimidos pelos AGPIs. O presente estudo teve como objetivo investigar os efeitos de dietas, ricas em ômega-3 ou ômega-6, consumidas ao longo de três gerações, sobre parâmetros bioquímicos e o nível de expressão de alguns genes relacionados ao metabolismo lipídico. Para este estudo foram utilizados ratas adultas, da linhagem Wistar/UFPel, compondo a geração fundadora, fêmeas que receberam ração com óleo de linhaça (Grupo OM, n=18) ou óleo de soja (Grupo CTL, n=18) durante toda a gestação. No desmame da F1 foram selecionadas 48 progênies fêmeas, então divididas em três grupos, fêmeas oriundas do Grupo OM, que continuaram a receber dieta com óleo de linhaça (Grupo OM/OM, n=16), fêmeas oriundas do Grupo OM, que passaram a receber dieta com óleo de soja (Grupo OM/CTL, n=16) e fêmeas oriundas do Grupo CTL, que continuaram a receber dieta com óleo de soja (Grupo CTL/CTL, n=16). No desmame da F2 foram selecionadas 16 progênies fêmeas de cada grupo que seguiram recebendo o mesmo tratamento (Grupo OM/OM/OM; Grupo OM/CTL/CTL e Grupo CTL/CTL/CTL). As fêmeas foram avaliadas no período pré parto (19±1 dias de gestação) e no pós-parto (21 dias após o parto). O perfil de ácidos graxo da dieta não afetou o consumo de ração e nem a taxa de prenhez (P>0,05), porém as fêmeas alimentadas com dieta rica em ômega-3 tiveram filhotes mais pesados (P=0,01). A dieta com alto nível de ômega-3 diminuiu os níveis séricos de triglicerídeos (P=0,04), e mantiveram constante os níveis de ácidos graxos não-esterificados (AGNEs), enquanto animais alimentados com uma proporção maior de ômega-6 tiveram níveis flutuantes de AGNEs, e um notável aumento no perído pós-parto da geração F2 (P=0,02). PPARα, RXRα, LXRα and SREBP-1c foram regulados pelas dietas ao longo das gerações. No período pré-parto da geração F2, os animais alimentação com alto ômega-3 apresentaram uma menor expressão de LXRα (P<0,001), indicando sua efetividade em inibir a ação lipogênica. Nossos resultados indicam que os efeitos dos AGPIs no controle da lipólise e lipogênese é cumulativo ao longo das gerações e o ômega-3 exerce um controle mais efetivo.
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Pretel, Hermes [UNESP]. "Ação de biomateriais e laser de baixa intensidade na reparação tecidual óssea: estudo histológico em ratos." Universidade Estadual Paulista (UNESP), 2005. http://hdl.handle.net/11449/95494.
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pretel_h_me_arafo_prot.pdf: 4958895 bytes, checksum: 2233125e5e1962443593d9b99271bb22 (MD5)<br>Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)<br>A poliuretana derivada do óleo de mamona propicia estimulação na reparação óssea por apresentar propriedades de osteocondutividade auxiliando na neoformação óssea. Quanto a osteoindução, pode ser estimulada por fatores de crescimento, como a BMP, e por fatores físicos como o laser. O trabalho avaliou a regeneração óssea a partir da confecção de uma lesão na base da mandíbula de rato, preenchida com mamona particulada, acrescida do pool de BMP E Hidroxiapatita (HA) absorvível. Posteriormente aplicou-se ou não um estímulo local com o laser de baixa intensidade. O aparelho utilizado foi o Laser beam (Semicondutor de Arseneto de Gálio-Alumínio, infravermelho - 785nm, 35mW). Foram usados 60 ratos Holtzman, divididos em quatro grupos de 15 animais, e estes subdivididos em 5 animais por período de análise, da seguinte forma: Grupo Controle (somente defeito); Grupo Experimental com estimulação laser (dose=178J/cm2; energia=1,4J); Grupo Experimental com mamona particulada acrescido de (BMP-HA); Grupo Experimental com mamona particulada acrescido de (BMP-HA), e estimulação laser (dose=178J/cm2; energia=1,4J). Os ratos foram sacrificados nos períodos de 15,45 e 60 dias; as mandíbulas foram removidas e processadas para inclusão em parafina, e os cortes de 6um foram corados por H&E, Tricrômico de Massom e Picro sirius. Os resultados histológicos mostraram formação óssea em todos os grupos. Nos grupos com o laser, a resposta tecidual foi antecipada em relação aos demais grupos promovendo a rápida neoformação da matriz óssea.<br>It suggest that polyurethane achieved from (Ricinus communis) induces bone repair because their osteoconductivity properties. In concerning the bone-inducing, that promotes osseous neoformation, it has been stimulate by growth factors, as bone morphogenetic protein (BMP), and laser therapy. The aim of this study was to evaluate osseous regeneration after mandible defects created in rats, and coveried with polyurethane resin partices (Ricinus communis), added with BMP and absorbable Hydroxyapatite (HA), stimulated or not by Laser beam. It was used the laser equipment Laser beam (Infra-red, continuous, Gallium-arsenide, 785nm, 35mW). Were utilized for this study 60 rats (Holtzman), were distributed in 4 groups of 15 animals. The control group (with only defect); the experimental group with laser stimulated (fluency=178J/cm2; energy=1,4J); the experimental group with resin particles added with (BMP-HA), and another similar group with laser stimulation (fluency=178J/cm2; energy=1,4J). The animals were then sacrified at the 15th, 45th and 60th days; mandibles were removed and processed for light microscopy. The histological examination samples were stain with H&E, Tricomic of Masson and Sirius Red. The results showed osseous neoformation in all groups. However, in the groups with laser stimulation the tissue response presented demonstrating earlier bone matrix formation.
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Chieh, Roberto Shanrey. "Indicadores financeiros trimestrais para prever falências nos setores de mineração, óleo e gás." reponame:Repositório Institucional do FGV, 2018. http://hdl.handle.net/10438/24613.
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Por gentileza a justar os seguintes itens:
. Retirar o acento da palavra "Getúlio"
. Na folha de assinaturas, retirar a frase "Folha de Aprovação"
Após a realização dos ajustes, peço que faça uma nova submissão.
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Previous issue date: 2018-07-31<br>O objetivo dessa dissertação é identificar os melhores modelos para prever falência de empresas dos setores de mineração, óleo e gás no período entre 1998 e 2017. Em termos metodológicos, buscou-se estimar um modelo de regressão logística para prever as falências das empresas por meio de indicadores financeiros. Estimam-se modelos com dados anuais e trimestrais utilizando informações dos últimos três, dois e um ano anteriores às falências, contados a partir de um ano antes da formalização da falência. Conclui-se que o melhor modelo é aquele que utiliza as informações mais recentes, do último ano, e com dados trimestrais. As variáveis de patrimônio líquido sobre passivo total e fluxo de caixa de investimentos sobre passivo total se destacaram dentre os demais indicadores, sendo somente a primeira significativa em todos os modelos. O melhor modelo teve 79,1% de acerto geral e 85,5% de acerto para as empresas que faliram.<br>The objective of this study is to identify the best models for predicting bankruptcy of companies from the mining, oil and gas industries between 1998 and 2017. It was estimated a logistic regression model to predict business failure given their financial indicators. It was estimated models with yearly and quarterly information figures using figures from the last three years, last two years, and also last one year prior to the year just before the formalization of the bankruptcy event. The results show that the best model is the one using the most recent information, from the last one year, and using quarterly available data. The ratios total equity to total liabilities and cash flow from investments to total liabilities are the most important indicators to predict bankruptcy, even though only the first one is significant in all models. The best model correctly predicted 79.1% among all firms and 85.5% of the firms that went bankrupt.
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Steimes, Johan. "Performance study and modelling of an integrated pump and gas-liquid separator system: Optimisation for aero-engine lubrication systems." Doctoral thesis, Universite Libre de Bruxelles, 2013. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209365.
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A system able to simultaneously separate and pump a gas-liquid mixture was developed.<p>It works efficiently and can be used in many applications (nuclear power plants,<p>pulp and paper processing, petroleum extraction, etc.). However, this pump and separator<p>system (PASS) was especially designed to handle air-oil mixture generated in<p>aero-engine lubrication systems. The PASS combines three important functions of the<p>scavenge part of the lubrication system: the deaeration and deoiling of the air-oil mixture<p>generated in the bearing and gearbox sumps and the pumping of the oil towards<p>the tank. These are critical functions for the engine. Indeed, a poor deoiling efficiency<p>leads to a high oil consumption. This reduces the flight endurance, increases the size<p>and weight of the oil tank and has a negative impact on the environment. Poor deaeration<p>and pumping characteristics lead to problems in the cooling and the lubrication of<p>the engine bearings.<p><p>Integrating a PASS into the lubrication system allows considerable improvements<p>(and simplification) to the lubrication system architecture. An important number of<p>components are suppressed: the vent lines, the deoiler, the cyclone deaerator and the<p>scavenge pumps. This reduces the size and the weight of the lubrication system and<p>increases its reliability. Furthermore, an important part of this PhD thesis focuses on<p>reducing the oil consumption in the PASS. This improves the flight endurance, reduces<p>engine maintenance and working costs and is profitable to the environment.<p><p>In addition to the development of an advanced PASS design system, the objective of<p>this thesis was to obtain a good understanding of the separation processes occurring in<p>the PASS and to develop theoretical models able to predict the separation performance<p>for every working condition encountered in a typical aircraft flight. To achieve this<p>goal, three main tasks were performed: the development of different two-phase measurement<p>systems, the experimental tests of four different PASS architectures and the<p>theoretical development (after an extensive literature review) of correlations predicting<p>the performance of the PASS in function of the working conditions. Five specific aspects<p>of the PASS were studied: the inlet flow, the deoiling efficiency, the deaeration efficiency,<p>the pumping efficiency and the pressure drop. Finally, the models that have been developed<p>with the help of the measurement systems and of the experiments have been<p>integrated in a complete model of the lubrication system (under the EcosimPro modelling<p>environment). This helps to predict real in flight PASS working conditions and<p>performance. Indeed, the PASS is very sensitive to the engine working conditions and<p>an optimisation of the prototype size and performance is only feasible with an accurate<p>knowledge of these working conditions and a complete lubrication system model.<p>Finally, with the results of this PhD thesis, a new PASS design, optimised for different<p>aero-engine lubrication systems, is presented.<br>Doctorat en Sciences de l'ingénieur<br>info:eu-repo/semantics/nonPublished
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Petit, Claire. "Méta-analyse en réseau et cancer ORL : utilité des critères de jugement multiples Individual Patient Data Network Meta-Analysis Using Either Restricted Mean Survival Time Difference or Hazard Ratios: Is There a Difference? A Case Study on Locoregionally Advanced Nasopharyngeal Carcinomas." Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPASR010.
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Les cancers des voies aéro-digestives supérieures, qu’ils soient des carcinomes épidermoïdes “classiques” ou des carcinomes indifférenciés du nasopharynx sont traités par des associations thérapeutiques en cas de maladie localement avancée. Le traitement loco-régional en est le socle, avec une chirurgie et/ou une radiothérapie. Cette radiothérapie peut être standard (66-70 Grays en 33-35 séances) ou avoir un fractionnement modifié (hyperfractionnement ou accélération). Une chimiothérapie est souvent associée à ces traitements, avec différents temps d’administration possible : en induction, en concomitant ou en adjuvant.De nombreux essais randomisés ont comparé différentes associations de traitements entre elles. Une méta-analyse en réseau permet une analyse groupée de tous ces essais randomisés, en utilisant les informations directes et indirectes disponibles pour déterminer l’efficacité relative des traitements.L’objectif de cette thèse était la réalisation de méta-analyses en réseau de type fréquentiste en utilisant les données individuelles de trois méta-analyses classiques :- combinaison de deux méta-analyses pour les carcinomes épidermoïdes (MACH-NC et MARCH, 115 essais, 28 978 patients et 16 modalités de traitement)- une méta-analyse pour les carcinomes du nasopharynx (MAC-NPC, 28 essais, 8 214 patients et 8 modalités de traitement) ;avec l’utilisation de différents critères de jugement (survie globale, survie sans progression ou sans évènement, contrôle loco-régional et métastatique, décès liés ou non au cancer) et différentes mesures pour ces critères de jugement : hazard ratio et différence de survie moyenne restreinte<br>Locally advanced head and neck cancers, whether “classical” squamous cell carcinomas or undifferentiated carcinomas of the nasopharynx, are treated by multimodality therapy. Loco-regional treatment is the main therapy, with surgery and/or radiotherapy. This radiotherapy can be standard (66-70 Grays in 33-35 fractions) or can have a modified fractionation (hyperfractionation or acceleration). Chemotherapy is often associated to these treatments, with different timing: induction, concomitant or adjuvant.Several randomized trials have compared different combinations of treatments. A network meta-analysis allows performing a pooled analysis of all these randomized trials, using the direct and indirect information available to determine the relative efficacy of the treatments.The objective of this doctoral thesis was to perform frequentist network meta-analyses using individual patient data from three standard meta-analyses:- combination of two meta-analyses for squamous cell carcinomas (MACH-NC and MARCH, 115 trials; 28,978 patients and 16 modalities of treatment);- one meta-analysis for nasopharyngeal carcinomas (MAC-NPC, 28 trials; 8,214 patients and 8 modalities of treatment);with different endpoints (overall survival, progression-free or event-free survival, locoregional and metastatic control, cancer-related or non-cancer-related deaths) and different measures for these endpoints: hazard ratio and restricted mean survival time difference
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Gallota, Fabiana Dias Costa. "Avaliação dos níveis de concentração e identificação de fontes de hidrocarbonetos na Bacia do Alto Iguaçu: estudo de caso pós derrame acidental de óleo na refinaria Presidente Getúlio Vargas." Niterói, 2016. https://app.uff.br/riuff/handle/1/1669.
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GALLOTTA_30_06_14.pdf: 62695484 bytes, checksum: 33335ee3affc2bcffb11fc10caf9ae3f (MD5)<br>Universidade Federal Fluminense. Instituto de Química. Programa de Pós-Graduação em Geociências-Geoquímica. Niterói, RJ<br>Os hidrocarbonetos presentes no ambiente consistem em misturas complexas de
compostos derivados de múltiplas fontes. Os combustíveis fósseis representam a
principal contribuição, devido à taxa e escala espacial, em que o petróleo tem sido
usado como fonte de energia e matéria-prima para a indústria química. O objetivo
deste estudo foi avaliar os níveis de concentração e identificar fontes de
hidrocarbonetos na Bacia do Alto Iguaçu e, em especial, na área de influência da
Refinaria Presidente Getúlio Vargas (REPAR). Além dos fatores de poluição crônica,
a área de estudo foi alvo de um derrame acidental de petróleo em julho de 2000.
Diversos indicadores em diferentes compartimentos ambientais (água superficial,
sedimento, solo e água subterrânea) foram avaliados na fase pós-derrame e no
monitoramento ambiental ao longo de várias campanhas por mais de uma década.
Os esforços de avaliação foram concentrados nos seguintes indicadores: os nalcanos,
os alcanos isoprenoides, os hidrocarbonetos policíclicos aromáticos (HPA),
os biomarcadores de petróleo e ainda o total de hidrocarbonetos de petróleo (THP).
Os resultados identificaram como principal aporte de matéria orgânica para as águas
superficiais dos rios Barigüi e Iguaçu, os fluxos materiais originados em região a
montante do acidente, refletindo a contribuição antropogênica crônica da cidade de
Curitiba. Em 2007 e 2008, as concentrações de THP e HPA nas águas superficiais e
sedimentos dos rios Barigüi e Iguaçu refletem uma expressiva melhoria nas
condições desses rios em relação a 2000. Na área interna da refinaria (Ponto Zero),
observou-se uma nítida diminuição (atenuação) natural das concentrações de THP
no solo em todas as profundidades dos perfis amostrados ao longo do tempo nos
Banhados 1 e 4 e, em particular, uma diminuição importante das concentrações
entre 2004 e 2007. Para a identificação das fontes de hidrocarbonetos foram
utilizadas razões diagnósticas e quimiometria. As razões diagnósticas calculadas a
partir de concentrações de HPA sugeriram que, na maioria dos sedimentos dos Rios
Barigüi e Iguaçu coletados nas campanhas de 2000 e 2001, a fonte petrogênica é a
principal. Somente na estação a montante do acidente no Rio Barigüi, a fonte
pirolítica predominou nestas duas campanhas. As razões diagnósticas que
apresentaram maior eficiência na identificação de fontes de hidrocarbonetos nos
sedimentos dos rios Barigüi e Iguaçu foram: ΣC1-Fenantrenos/Fenantreno; e (ΣHPA
parentais de 3-6 anéis)/(Σ5 séries de HPA alquilados). A identificação de fontes
através de razões diagnósticas calculadas a partir de áreas e alturas de picos
cromatográficos demonstrou sua aplicabilidade verificando a relação entre os
compostos encontrados em amostras de solo da área interna da refinaria com a
amostra de petróleo derramado no acidente, após quase uma década da ocorrência
do vazamento. A identificação de fontes através método de quimiométrico baseado
na análise de componentes principais (ACP) de seções pré-processadas e
combinadas dos Cromatogramas de Íons Selecionados (CIS) mostrou que as
amostras mais contaminadas estão na área interna da refinaria. Essas amostras
apresentam um padrão de distribuição petrogênica e diferentes graus de
intemperismo. As amostras da área externa à refinaria (Guajuvira, General Lúcio e
Balsa Nova) são menos ou não contaminadas e/ou contém uma mistura de
contribuições diagenéticas, pirolíticas e petrogênicas onde predominam diferentes
proporções. Os locais mais distantes da atividade industrial (Balsa Nova) contem,
como esperado, os níveis mais baixos de contaminação por HPA. Os resultados de
biomarcadores demonstraram que não há evidências para concluir que as amostras
da área externa à refinaria e o óleo Cusiana vazado tenham a mesma origem. Os
resultados ao longo dos rios Barigüi e Iguaçu e do Ponto Zero demonstraram que as
ações de emergência para a contenção do óleo foram adequadas para os rios, e que
a contaminação decorrente do derrame ficou predominantemente contida no Ponto
Zero e diminuiu significativamente após uma década.<br>Hydrocarbons present in the environment consist of complex mixtures of compounds
derived from multiple sources. The main contribution lies on fossil fuel inputs due to
the rate and spatial scale by which petroleum has been used as an energy source
and chemical feedstock. The aim of this study was to assess the concentration levels
and identify sources of hydrocarbons in the Upper Iguaçu Watershed and, in
particular, in the area of influence of the President Getulio Vargas Refinery (REPAR).
In addition to the factors of chronic pollution, the study area was the scenario of an
acute accidental oil spill in July 2000. Numerous indicators in different environmental
compartments (surface water, sediment, soil and groundwater) were assessed in the
post spill phase and during the environmental monitoring programs over the course
of several campaigns for more than a decade. Assessment efforts were concentrated
on the following indicators: n-alkanes, alkanes isoprenoids, polycyclic aromatic
hydrocarbons (PAH), petroleum biomarkers and total petroleum hydrocarbons (TPH).
The results identified as the main contribution of organic matter to surface waters of
the Barigüi and Iguaçu Rivers the materials flows originated in the region upstream of
the accident, reflecting chronic anthropogenic contribution of the city of Curitiba. In
2007 and 2008, the TPH and PAH concentrations in surface waters and sediments of
the Barigüi and Iguaçu Rivers revealed a significant improvement in the conditions of
these rivers when compared with 2000. Inside the refinery area (Point Zero), it was
observed a clear natural decrease (attenuation) of the concentrations of TPH in the
soil at all depths sampled over time in Marshes 1 and 4 and, in particular, an
important decrease of concentrations between 2004 and 2007. Diagnostic ratios and
chemometrics were used to identity hydrocarbon sources. The diagnostic ratios
calculated from the concentrations of PAH suggested that, in the majority of
sediments from the Barigüi and Iguaçu Rivers collected in 2000 and 2001
campaigns, the main source is petrogenic. Only in the station upstream the accident
in the Barigüi River, the pyrolytic source predominated in these two campaigns. The
diagnostic ratios that presented higher efficiency in identifying sources of
hydrocarbons in sediments of the Barigüi and Iguaçu Rivers were: ΣC1-
Phenantrenes/Phenanthrene; and (Σ3-6 rings parental PAH)/(Σ5 alkylated PAH
series). The source identification through diagnostic ratios calculated from heights
and areas of chromatographic peaks demonstrated its applicability establishing a
relationship between the compounds found in soil samples of the internal area of the
refinery and the sample of the oil spilled in the accident, after nearly a decade of
occurrence of the spillage. The source identification through chemometric method
based on principal components analysis (PCA) of preprocessed and combined
sections of Selected Ion Chromatograms (SIC) showed that the most contaminated
samples are inside the refinery area. These samples present a petrogenic pattern
and different weathering degrees. Samples from outside the refinery area (Guajuvira,
General Lúcio e Balsa Nova) are either less or not contaminated, and/or contain
mixtures of diagenetic, pyrogenic and petrogenic inputs where different proportions
predominate. The locations farthest away from industrial activity (Balsa Nova)
contain, as expected, the lowest levels of PAH contamination. The biomarkers results
do not show any evidences to conclude positive matches between the samples from
outside the refinery area and the spilled Cusiana oil. The results along Barigüi and
Iguaçu rivers and Point Zero demonstrated that emergency actions to contain the oil
were appropriate for the rivers, and that the contamination resulting from the spill was
mostly contained in the Point Zero and decreased significantly after one decade