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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
111

Coeficiente de partição do C'O IND 2' no processo de injeção de água carbonatada / C'O IND 2' partition coefficient in the process of carbonated water injection

Greenup Carrazana, Lisbet 21 August 2018 (has links)
Orientador: Osvair Vidal Trevisan / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica e Instituto de Geociências / Made available in DSpace on 2018-08-21T10:14:32Z (GMT). No. of bitstreams: 1 GreenupCarrazana_Lisbet_M.pdf: 2844806 bytes, checksum: ff0d858899d8b8fdc591e5be21757f81 (MD5) Previous issue date: 2012 / Resumo: O processo de recuperação de óleo pelo deslocamento com CO2 é um método líder na recuperação melhorada de óleos leves e médios. No entanto, a rápida irrupção do CO2 no poço produtor e a baixa eficiência de varrido diminuem sua atratividade. Uma alternativa mais eficiente é a injeção de água carbonatada (IAC). Um dos fatores mais importantes para a compreensão deste processo é o coeficiente de partição, que quantifica a quantidade de CO2 transferida da água carbonatada injetada para o óleo do reservatório durante o deslocamento. A sua determinação é de vital importância para o planejamento e a simulação da injeção de água carbonatada. Contudo, há poucos estudos experimentais publicados sobre o levantamento deste parâmetro. O objetivo deste trabalho é estudar o coeficiente de partição do CO2 entre as fases óleo e água, para determinadas condições PVT e obter uma gama de parâmetros que possam ajudar na simulação e avaliação do processo para uma futura aplicação no campo. Considerando que a repartição de CO2 entre ambas as fases é refletida no aumento dos volumes iniciais da salmoura e do óleo (testes de inchamento), é desenvolvida uma metodologia baseada num estudo teórico e experimental, que avalia o aumento do volume conjunto da mistura do óleo recombinado e a salmoura carbonatada ao entrarem em contato, nas condições de injeção (pressão de 9.000 psi, temperatura de 64 ºC. Outras medidas de interesse, na caracterização do processo, são o ponto de bolha, o fator volume-formação do óleo, a razão gás-óleo, viscosidades e densidades. Duas etapas foram desenvolvidas para a avaliação do inchamento da mistura de água carbonatada com óleo: teórica, com um programa de simulação de PVT (WinProp), e experimental, com um sistema de garrafas PVT e com uma célula PVT visual. Dentro dos resultados mais significativos consta uma caracterização do óleo do reservatório com sua representação numérica por meio da equação de estado de Peng-Robinson (1978). Assim como a estimativa do coeficiente de partição do CO2 entre as fases óleo e água para as condições especificadas de pressão, temperatura e razão molar óleo-água. Alem disso, descreve-se uma metodologia para a determinação do coeficiente de partição, que durante sua execução, revelou vários aspetos, que fornecem um grande aprendizado para trabalhos futuros relacionados com o tópico / Abstract: Oil recovery process by carbon dioxide displacement is the leader improved recovery method applied to light and medium oil reservoirs. Nevertheless, the effects of early breakthrough and poor reservoir sweep let it a less attractive method. The flooding with carbonated water is a more efficient choice. The partition coefficient is one of the key parameters driving the process; it quantifies the CO2 amount transferred from the injected carbonated water to reservoir oil. The aim of the present investigation is to study the CO2 partition coefficient between oil and water phases for specific PVT conditions and to obtain some experimental data for the reservoir simulation input. Taking into account that CO2 partition between both phases reflects in the increase of the initial volumes of the brine and oil, a methodology based on theoretical and experimental study was created. It made possible to estimate, under injection condition (9000 psi the pressure and 64 ºC the temperature), the swelling of the final volume of carbonate water and oil mixture. Other essential parameters, as reservoir oil bubble point, oil formation volume factor, gas oil ratio, densities and viscosities were measured. Two stages were performed to evaluate the mixture swelling effect of carbonate water with oil: the simulation modeling, by using the PVT simulation program (WinProp) and lab experiments, by using a PVT bottle and a PVT cell. With the obtained results the reservoir oil was characterized with its numerical representation via a Peng-Robinson equation of state (1978). The CO2 partition coefficient value between oil and water was assessed for specific conditions of pressure, temperature and molar water-oil ratio. Also a methodology for estimation of the partition coefficient was described and tested / Mestrado / Reservatórios e Gestão / Mestra em Ciências e Engenharia de Petróleo
112

Prediction of drug distribution in rat and human

Graham, Helen Sarah January 2012 (has links)
Many methods exist in the literature for the prediction of pharmacokinetic parameters which describe drug distribution in rat and human, such as tissue-to-plasma partition coefficients (Kps) and volume of distribution (Vss). However, none of these methods make use of the in vivo information obtained at the early stages of the drug development process in the form of plasma concentration vs. time profiles. The overall aim of the presented study was to improve upon an existing Kp prediction method by making use of the distribution information contained within this experimental data. Chapter 2 shows that Kp values can be successfully obtained experimentally, but that this process is expensive and time-consuming. Chapter 3 compares six Kp prediction methods taken from the literature for their ability to predict the Kp values of 80 drugs. The Rodgers et al. model was found to be the most accurate, with over 77% of predictions within 3-fold of experimental values. This Chapter also discusses the Vss prediction ability of some of these methods, with the Poulin & Theil and Rodgers et al. models shown to be the most accurate predictors for rat Vss and human Vss respectively. Chapter 4 investigates the relationship between muscle Kp and the Kps of all other tissues, to show that experimental muscle Kp can be used as a surrogate from which all other non-adipose Kp values can be predicted. However, the predictions made using this method were shown to be less accurate than predictions made by the Rodgers et al. model for the same dataset of drugs. A relationship was identified between muscle Kp and tumour Kp in rat, suggesting a potential way to predict tumour Kp in the future. In Chapter 5, a novel method is developed whereby Kp predictions made by the Rodgers et al. model are updated using prior information obtained from the in vivo concentration-time profile. These updated values are then used within a physiologically-based pharmacokinetic (PBPK) model and are shown in Chapter 6 to generate improved predictions for other pharmacokinetic parameters such as Vss and clearance in both rat and human. 100% of human Vss predictions made by the most accurate of the novel methods presented here were within 3-fold of experimental values, compared to 68.8% of predictions made by the Rodgers et al. model. The work presented here has highlighted the need for a more accurate method for the prediction of Kp values, and has addressed this need by generating a model which improves upon the most accurate Kp prediction method currently found in the literature. This will lead to an increase in confidence in the use of predicted pharmacokinetic parameters within PBPK modelling.
113

Thermodynamics of Mobile Order Theory: Solubility and Partition Aspects

De Fina, Karina M. 08 1900 (has links)
The purpose of this thesis is to analyze the thermochemical properties of solutes in nonelectrolyte pure solvents and to develop mathematical expressions with the ability to describe and predict solution behavior using mobile order theory. Solubilities of pesticides (monuron, diuron, and hexachlorobenzene), polycyclic aromatic hydrocarbons (biphenyl, acenaphthene, and phenanthrene), and the organometallic ferrocene were studied in a wide array of solvents. Mobile order theory predictive equations were derived and percent average absolute deviations between experimental and calculated mole fraction solubilities for each solute were as follows: monuron in 21 non-alcoholic solvents (48.4%), diuron in 28 non-alcoholic solvents (60.1%), hexachlorobenzene (210%), biphenyl (13.0%), acenaphthene (37.8%), phenanthrene (41.3%), and ferrocene (107.8%). Solute descriptors using the Abraham solvation model were also calculated for monuron and diuron. Coefficients in the general solvation equation were known for all the solvents and solute descriptors calculated using multilinear regression techniques.
114

Characterizations of Some Combinatorial Geometries

Yoon, Young-jin 08 1900 (has links)
We give several characterizations of partition lattices and projective geometries. Most of these characterizations use characteristic polynomials. A geometry is non—splitting if it cannot be expressed as the union of two of its proper flats. A geometry G is upper homogeneous if for all k, k = 1, 2, ... , r(G), and for every pair x, y of flats of rank k, the contraction G/x is isomorphic to the contraction G/y. Given a signed graph, we define a corresponding signed—graphic geometry. We give a characterization of supersolvable signed graphs. Finally, we give the following characterization of non—splitting supersolvable signed-graphic geometries : If a non-splitting supersolvable ternary geometry does not contain the Reid geometry as a subgeometry, then it is signed—graphic.
115

Tre-stegsmetod för att kvantifiera komplexitet för IT-förslag

Al-Qaysi, Ibrahim, Ghidei, Yonas January 2016 (has links)
Moderna företag är under ständig förändring. Företagen behöver således förändra, bygga ut och modifiera de applikationer som stödjer verksamheten. Att göra ändringar i arkitekturer på stora IT-system är inte heltbekymmerfritt. Det är ofta väldigt dyrt och tidskrävande. Problemet är att det inte finns några enkla metoder för att kvantifiera komplexitet på IT-förslag i tidigt skede av en implementation. Många verksamheter har således behov avatt kvantifiera komplexiteten på IT-förslag i deras beslutsprocess för att avgöra vilka system som är dyra och tidskrävande att implementera. Ett av dem är Sveriges militära försvarsorganisation, Försvarsmakten. Syftet förstudien blir sålunda att presentera en metod för att kvantifiera komplexitet och optimera implementation för IT-förslag. Målet för studien är därmed att presentera en modell som gör det möjligt för verksamheter att identifiera komplexa förslag som kan medföra onödiga projektrisker. Denna studie använder sig utav en kombination av kvalitativ och kvantitativ forskningsmetod med en induktiv forskningsansats. Studien evaluerar vilka olika sätt Försvarsmaktens mobilapplikation, FMTK kan implementeras på och vilken av implementationerna som är mest optimal beträffande komplexitet. Därefter presenteras resultatet för studien, Tre-stegsmetoden som inkorporerar den bästa implementationen. Slutligen drar studien slutsatsen, med hjälp av analyser och utvärderingar, att Tre-stegsmetoden är överlägsen andra metoder. / Modern enterprises are under constant change. Therefore, enterprises need to change, extend and modify the applications that support their businesses. Making changes in the architectures of large IT-systems however, are not straightforward. It is often very costly and time consuming. The problem is that there are no easy methods to quantify complexity and optimize an implementation in early phases of an application construction. Thus, many companies are in need of a method to quanitfy complexity of their IT-businessproposals in order to facilitate their decision-making process. One of them is the Swedish Armed Forces (sv. Försvarsmakten). The purpose of this study is therefore to present a simple method to quantify complexity and optimize implementation for IT-proposals. The purpose aligns with the goal, which is to present a model, which forms the basis for IT-proposals, for companies to consider in their process. This study uses a combination of a qualitative and quantitative research with an inductive research approach. Furthermore, this study evaluates in which ways Swedish Armed Forces application FMTK can be implemented and which implementations that are most optimal in terms of complexity. A method which incorporates the implementation is thereafter presented as a result of the study. Conclusively, the study shows with the help of analyses and evaluations that the presented method, namely the Three-stepmethod is superior to other methods.
116

Partitioning of Urban Transportation Networks Utilizing Real-World Traffic Parameters for Distributed Simulation in SUMO

Ahmed, Md Salman, Hoque, Mohammad A. 27 January 2017 (has links)
This paper describes a partitioning algorithm for real-world transportation networks incorporating previously unaccounted parameters like signalized traffic intersection, road segment length, traffic density, number of lanes and inter-partition communication overhead due to the migration of vehicles from one partition to another. We also describe our hypothetical framework for distributed simulation of the partitioned road network on SUMO, where a master controller is currently under development using TraCI APIs and MPI library to coordinate the parallel simulation and synchronization between the sub-networks generated by our proposed algorithm.
117

Partition Based Phylogenetic Search

Sundberg, Kenneth A. 04 August 2010 (has links) (PDF)
Evolutionary relationships are key to modern understanding of biological systems. Phylogenetic search is the means by which these relationships are inferred. Phylogenetic search is NP-Hard. As such it is necessary to employ heuristic methods. This work proposes new methods based on viewing the relationships between species as sets of partitions. These methods produce more parsimonious phylogenies than current methods.
118

Calculated Equilibrium Constants for Isotopic Exchange Reactions Involving Sulfur-Containing Compounds

Tudge, Allan 05 1900 (has links)
<p> Recent investigations by H. G. Thode, J. Macnamara and C. Collins have shown that the S^32/S^34 ratio in natural sulfur-containing compounds varies by as much as five percent. These wide-spread variations suggest that fractionation of the sulfur isotopes occurs in natural processes due to differences in the chemical properties of isotopic molecules. In order to determine the magnitude of the effects that could be expected, partition function ratios for isotopic molecules containing sulfur and equilibrium constants for many isotopic exchange reactions involving sulfur have been calculated by methods of statistical mechanics. The results of these calculations are discussed. </p> / Thesis / Master of Science (MSc)
119

From static to dynamic: an investigation of flexible architecture

Wittkugel, Andrew E. 25 September 2012 (has links)
No description available.
120

Removable Singularities for Holder Continuous Solutions of the Fractional Laplacian.

Alghamdi, Ohud 26 April 2016 (has links)
No description available.

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