• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 1126
  • 455
  • 228
  • 188
  • 115
  • 68
  • 35
  • 25
  • 20
  • 18
  • 18
  • 18
  • 18
  • 18
  • 18
  • Tagged with
  • 2760
  • 394
  • 290
  • 245
  • 167
  • 165
  • 163
  • 154
  • 148
  • 147
  • 138
  • 127
  • 125
  • 123
  • 115
  • 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.
271

Enzymatic hydrolysis of cellulose : a kinetic study

Van Dyke, Bingham Hood January 1972 (has links)
Thesis (Sc. D.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, 1972. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND SCIENCE / Vita. / Bibliography: leaves 308-329. / by Bingham H. Van Dyke, Jr. / Sc.D.
272

Internal motion of linear chain and gel networks in different quality solvent.

January 2011 (has links)
Dai, Zhuojun. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references. / Abstracts in English and Chinese. / 摘要 --- p.i / ABSTRACT --- p.iii / ACKNOWLEDGEMENT --- p.v / Chapter Chapter 1 --- Introduction and Background --- p.-1- / Chapter 1.1 --- General introduction to internal motions --- p.-1- / Chapter 1.1.1 --- Definition of translational diffusion and internal motions --- p.-1- / Chapter 1.1.2 --- Theoretical background of internal motions --- p.-1- / Chapter 1.2 --- Investigation of internal motions on LLS --- p.-4- / Chapter 1.2.1 --- General introduction on investigation of internal motion by LLS --- p.-4- / Chapter 1.2.2 --- Theory on internal motion detected by LLS --- p.-5- / Chapter 1.3 --- Laser light scattering --- p.-6- / Chapter 1.3.1 --- General introduction to laser light scattering --- p.-6- / Chapter 1.3.2 --- Data process about internal motions in LLS --- p.-9- / Chapter 1.4 --- Notes and References --- p.-12- / Chapter Chapter 2 --- Internal motions of PNIPAM chains in 6 and bad solvent --- p.-15- / Chapter 2.1 --- Introduction --- p.-15- / Chapter 2.2 --- Experimental section --- p.-15- / Chapter 2.2.1 --- Sample preparation --- p.-15- / Chapter 2.2.2 --- Dynamic laser light scattering --- p.-16- / Chapter 2.3 --- Result and discussion --- p.-16- / Chapter 2.4 --- Conclusion --- p.-23- / Chapter 2.5 --- Notes and References --- p.-25- / Chapter Chapter 3 --- Internal motions of PNIPAM microgels in 6 and bad solvent --- p.-26- / Chapter 3.1 --- Introduction --- p.-26- / Chapter 3.2 --- Experimental section --- p.-26- / Chapter 3.2.1 --- Sample preparation --- p.-26- / Chapter 3.2.2 --- Dynamic laser light scattering --- p.-21- / Chapter 3.3 --- Result and discussion --- p.-27- / Chapter 3.4 --- Conclusion --- p.-30- / Chapter 3.5 --- Notes and References --- p.-31- / Chapter Chapter 4 --- Examination on the internal motions variations with solvent quality of Polystyrene chains --- p.-32- / Chapter 4.1 --- Introduction --- p.-32- / Chapter 4.2 --- Experimental Section --- p.-32- / Chapter 4.2.1 --- Sample preparation --- p.-32- / Chapter 4.2.2 --- Dynamic laser light scattering --- p.-33- / Chapter 4.3 --- Result and discussion --- p.-33- / Chapter 4.4 --- Conclusion --- p.-36- / Chapter 4.5 --- Notes and References --- p.-38- / Chapter Chapter 5 --- Examination on the internal motions variations with solvent quality of Poly(methyl methacrylate) chains --- p.-40- / Chapter 5.1 --- Introduction --- p.-40- / Chapter 5.2 --- Experimental Section --- p.-40- / Chapter 5.2.1 --- Sample preparation --- p.-40- / Chapter 5.2.2 --- Dynamic laser light scattering --- p.-41- / Chapter 5.3 --- Result and discussion --- p.-41- / Chapter 5.4 --- Conclusion --- p.-45- / Chapter 5.5 --- Notes and References --- p.-46-
273

Variação da pressão sistólica como indicadora precoce de hipovolemia e guia de reposição volêmica com solução hiperosmótica e hiperoncótica no cão /

Paiva Filho, Odilar January 2001 (has links)
Orientador: José Reinaldo Cerqueira Braz / Resumo: A detecção da hipovolemia insidiosa no intra-operatório é difícil devido a pouca especificidade dos sinais clínicos e hemodinâmicos. Estudos introduziram um novo método para avaliação da pré-carga, baseados na análise da variação da pressão sistólica (VPS) durante a ventilação mecânica. O presente estudo tem por objetivo avaliar se a VPS e sua derivada delta down (ddown) são indicadoras precoces de hipovolemia e guias de reposição volêmica com solução hiperosmótica e hiperoncótica no cão anestesiado submetido a hipovolemia. Doze cães sem raça definida, anestesiados com propofol, fentanil, rocurônio e isoflurano, e esplenectomizados, foram submetidos a sangramentos parciais de 5% da volemia até se atingir a retirada total de 20% da volemia (14 ml.kg-1). Após cada momento foram realizadas análises hemodinâmicas, respiratórias e sangüíneas. Em seguida, os cães foram submetidos à reposição volêmica com solução de NaCl a 7,5% em dextran 70 a 3,75% (4 ml.kg-1) em 10 minutos e novas análises foram realizadas aos 5 e 30 minutos após a reposição volêmica. A freqüência cardíaca não apresentou alteração... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The insidious hypovolemia detection in the intraoperative is difficult due to little specificity of clinical and hemodynamic signs. Studies introduced a new method for preload evaluation, based on systolic pressure variation analysis (SPV) during mechanical ventilation. The present study aims to evaluate if SPV and its derived delta down (ddown) are early indicator of hypovolemia, and guides of volemic replacement with hyperosmotic and hyperoncotic solution in anesthetized dogs submitted to hypovolemia. Twelve mogrel dogs, anesthetized with propofol, fentanyl, rocuronium and isoflurane, were submitted to graded haemorrhage of 5% of its volemia to reach the total of 20% of volemia (14 ml.kg-1). After every haemorrhage period, hemodynamic, ventilatory and blood atributes were studied. Imediately after, the dogs were submitted to volemic replacement with 7.5% NaCl solution in 3,75% dextran 70 (4 ml.kg-1) in 10 minutes, and the atributes were studied after 5 and 30 minutes following the volemic replacement. Heart rate was not changed significantly. Mean arterial pressure decreased significantly during haemorrhage, and increased... (Complete abstract, click electronic access below) / Mestre
274

Análise do Programa de Bochechos de flúor em escolares da 13ª Delegacia de Ensino da 3ª Divisão Regional de Ensino da Capital do Município de São Paulo / Analysis of the fluoride mouthwash program in schoolchildren of the 13th Delegation of Education of the 3rd Regional Division of Education of the City of São Paulo

Ilvaita Maria Morais de Carvalho Aly 08 May 1987 (has links)
O objetivo do presente estudo é a avaliação do programa de bochechos de solução de fluor realizada pela Divisão de Estudos, Normas e Programas do Departamento de Assistência ao Escolar da Secretaria de Educação do Estado de São Paulo. A análise consistiu em se observar a atuação do ministrador do bochecho, verificando-se conjuntamente o preparo da solução e o tempo de duração do mesmo, a quantidade da solução e a freqüência do bochecho proporcionado aos escolares, além da incidência de cárie ocorrida desde o início até o final das observações, comparando-a através da aplicação do índice CPOS com a incidência ocorrida com escolares nos quais o bochecho foi rigorosamente controlado. A ausência de prevenção verificada torna evidente que o método não está sendo executado corretamente. / The present study comprehends an evaluation of a program of fluoride solution mouthrinsing application worked out by the Branch of study, Norms and Programmes of the Schoolchild Assistance Division of the Sao Paulo State Department of Education, Brazil. The analysis has comprised the observation of the performance of the persons in charge of the mouthrinsing ministration, taking into account lenght of time spent, the quantity and concentration of solution and frequency of mouthrinsing offered to schoolchildren, besides the incidence of caries occurred since the beginning till the end of the observations, comparing this incidence - through the application of the CPOS index - to trat occurred in school children with whom the mouthrinsing was completely controlled. The absence of prevention observed indicates that the method is not being correctly performed.
275

Femtosecond study of the solvent cage effect : the ultrafast photodissociation and geminate recombination of organometallic dimers /

Oelkers, Alan Brian, January 2007 (has links)
Thesis (Ph. D.)--University of Oregon, 2007. / Typescript. Includes vita and abstract. Includes bibliographical references (leaves 178-191). Also available for download via the World Wide Web; free to University of Oregon users.
276

Metallosupramolecular chemistry in aqueous solutions applications in ribonuclease mimicry and molecular sensing /

Folmer-Andersen, Jan-Frantz Christian, January 1900 (has links) (PDF)
Thesis (Ph. D.)--University of Texas at Austin, 2006. / Vita. Includes bibliographical references.
277

On the Bidirectional Vortex Engine Flowfield with Arbitrary Endwall Injection

Akiki, Georges 01 August 2011 (has links)
In an attempt to generalize previous models of the bidirectional vortex mean flow, a new solution is presented that can cope with arbitrary injections and outlet conditions. In the process, the steady, inviscid and axisymmetric equations of motions are reduced to one partial differential equation for the stream function, known as the Bragg-Hawthorne equation, which is solved exactly. The solution is shown to be highly dependent on the imposed boundary conditions: the mean flow changes according to the manner by which the fluid is injected or extracted from the vortex chamber. From the stream function, the velocity is obtained along with the vorticity and pressure distributions which are carefully derived and analyzed. The results are then compared to several inviscid models found in the literature. After determining an exact inviscid solution to the problem, viscous effects at the core are added to overcome the known singularity that arises at the centerline. The governing equations are hence revisited while keeping the viscous diffusion term in the tangential momentum equation. The core region, where viscous effects lead to the onset of a forced vortex, is rescaled using appropriate transformations. An asymptotic approximation is then applied to linearize and solve the resulting ODE for the tangential vi velocity. The inner viscous solution is then matched to the outer inviscid result using Prandtl’s Matching Principle. Finally, the viscous correction is passed onto the vorticity and pressure formulations.
278

Unitary solutions of partial differential equations

Tarkhanov, Nikolai January 2005 (has links)
We give an explicit construction of a fundamental solution for an arbitrary non-degenerate partial differential equation with smooth coefficients.
279

Modélisation théorique de la spectroscopie d'actinides des solvatés. / Theoretical modelling of actinide spectra in solution.

Danilo, Cecile January 2009 (has links)
The framework of this PhD is the interpretation of Nuclear Magnetic Relaxation Dispersion experiments performed on solvated U4+, NpO2+ and PuO22+, which all have an f2 configuration. Unexpectedly the two actinyl ions have a much higher relaxivity than U4+. One possible explanation is that the electronic relaxation rate is faster for Uranium(IV) than for the actinyl ions. We address this problem by exploring the electronic spectrum of the three compounds in solution. A preliminary step is the computation of the electronic spectra of these three ions in gas phase. A two-step SOCI method has been used to investigate the spectroscopy in gas phase and in solution. The influence of electron correlation  (treated in the first step) and spin-orbit relaxation effects (considered in the second step) has been discussed thoroughly. The influence of the first hydration sphere and the bulk solvent effects has been investigated as well.Another issue that has been questioned is the accuracy of Density Functional Theory for the study of actinide species. This matter has been discussed by comparing its performance to wave-function based correlated methods. The chemical problem chosen was the water exchange in UO22+(H2O)5. This reaction can proceed via three pathways, the associative, the dissociative and the symmetric interchange. We looked at the two former ones using a model with one additional water in the second hydration sphere.The last part of the thesis dealt with the spectroscopy of coordinated Uranyl(V). Absorption spectrum of Uranyl(V) with various ligands has been recorded. The first sharp absorption band in the Near Infrared region were assigned to the Uranium centered 5f-5f transitions, but uncertainties remained for the assignment of transitions observed in the Visible region. We computed the spectra of naked UO2+ and [UO2(CO3)3]5- to elucidate the spectral changes induced by the carbonate ligands. / Cecile Danilo takes her PhD in collaboration with Uniersité Lille 1 under the cotutelle system
280

Finite Bargaining Problems

Wu, Hanji 15 May 2007 (has links)
Bargaining is a process to decide how to divide shared resources between two or more players. And axiomatic bargaining specifies desirable and simple properties the outcome of the bargaining should satisfy and identifies the solution that produces this outcome. This approach was first developed by John Nash in his seminal work(Nash 1950). Since then, numerous studies have been done on bargaining problems with convex feasible set or with non-convex but comprehensive feasible set. There is, however, little work on finite bargaining problems. In this dissertation, we study finite bargaining problems systematically by extending the standard bargaining model to the one consisting of all finite bargaining problems. For our bargaining problems, we first propose the Nash, Maximin, Leximin, Maxiproportionalmin, Lexiproportianlmin solutions, which are the counterparts of those that have been studied extensively in both convex and non-convex but comprehensive problems. We then axiomatically characterize these solutions in our context. We next introduce two new solutions, the maximin-utilitarian solution and the utilitarian-maximin solution, each of which combines the maximin solution and utilitarian solution in different ways. The maximin-utilitarian solution selects the alternatives from the maximin solution that have the greatest sum of individuals’ utilities, and the utilitarian-maximin solution selects the maximin alternatives from the utilitarian solution. These two solutions attempt to combine two important but very different ethical principles to produce compromised solutions to bargaining problems. Finally, we discuss several variants of the egalitarian solution. The egalitarian solution in finite bargaining problems is more complicated than its counterpart in either convex or non-convex but comprehensive bargaining problems. Given its complexity in our context, we start our inquiry by investigating two-person, finite bargaining problems, and then extend some of the analysis to n-person, finite bargaining problems. Our analysis of finite bargaining problems and axiomatic characterizations of the extensions of various standard solutions of convex/non-convex but comprehensive bargaining problems to finite bargaining problems will shed new light on the behavior of these solutions. Our new solutions will expand our understanding of the bargaining theory and distributive justice from a different perspective.

Page generated in 0.0578 seconds