Thesis (M.S.)--Florida State University, 2003. / Advisor: Dr. Ravindran Chella, Florida State University, FAMU-FSU College of Engineering, Dept. of Chemical Engineering. Title and description from dissertation home page (viewed Sept. 26, 2003). Includes bibliographical references.

Theoretical studies are presented in this thesis on the hydrodynamic dispersion due to electro-osmotic flow (EOF) through a parallel-plate or circular channel under the combined effects of wall heterogeneities, including surface topography, hydrodynamic slip, and zeta potential. These wall properties, which are periodically varied along the channel, are called wall patterns in general. The electric potential field and the velocity field of the EOF are determined by solving the linearized Poisson-Boltzmann (P-B) equation and the Stokes equation, respectively, subject to the spatially varying electrohydrodynamic boundary conditions caused by the wall patterns. In particular, for wall patterns with discrete step changes (in contrast with slowly varying and continuous ones), the solutions are expressed by Fourier series that satisfy the mixed-type boundary conditions. The effective expression for the dispersion is derived using the theory of homogenization by introducing multiple-scale variables and expansions. The effective dispersion coefficient is determined either by purely analytical analysis or numerical methods combined with analytical deduction, depending on the complexity of the problem formulation. This thesis consists of two parts. In the first part, the aggregate effect on the flow due to non-uniformly distributed wall properties is studied in two problems. The first problem considers the combined effects of wall corrugations and slippage modulation on pressure-driven cross (transverse) flow through a thin parallel-plate channel in terms of the hydrodynamic effective slip length and flow enhancement. The second problem considers the combined effects of charge distribution and slippage modulation on both longitudinal and transverse EOF through a channel with the same geometry in terms of the electroosmosis (EO) mobility and flow morphology. It is shown that the interaction between different wall patterns due to surface heterogeneity can play a significant role in determining the flow velocity as well as the local convection pattern, both quantitatively and qualitatively. In the second part, hydrodynamic dispersion due to EOF under the aggregate effect of surface heterogeneities in wall potential and hydrodynamic slippage is studied also in two problems. The first problem considers a limiting case where certain geometric and dynamic requirements are satisfied so that the theory of lubrication approximation can be applied to simplify the analysis, for which analytical solutions are obtained for the flow as well as the dispersion. The second problem is for a similar but more general case without using the lubrication approximation, in which the velocity of the flow, the dispersion coefficient and the plate height for the mass transfer are numerically determined after the mathematical formulation of the problem. It is remarkable that the introduction of hydrodynamic slippage can dramatically change the dispersion arising from EOF in various aspects, especially when both the slippage and electric potential are non-uniformly distributed on the channel wall. / published_or_final_version / Mechanical Engineering / Master / Master of Philosophy

Thesis (M.S.)--Brigham Young University. Department of Mechanical Engineering, 2004. / Includes bibliographical references (p. 79-81).

Thesis (Ph. D.)--West Virginia University, 2006. / Title from document title page. Document formatted into pages; contains xiv, 131 p. : ill. (some col.). Includes abstract. Includes bibliographical references.

Thesis (M.S.)--Brigham Young University. Dept. of Mechanical Engineering, 2005. / Includes bibliographical references (p. 91-94).

Thesis (Ph. D.)--Drexel University, 2004. / Includes abstract and vita. Includes bibliographical references (leaves 198-202).

Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2004. / Adviser: Ty A. Newell. Includes bibliographical references.

[pt] A presente dissertação apresenta o estudo da eletro- osmose em um solo residual gnaissico em ambiente laboratorial. O foco do trabalho foi direcionado ao desenvolvimento de equipamento e metodologia de ensaio. Duas células foram desenvolvidas, uma para amostras indeformadas e outra para amostras reconstituídas em laboratório.Os resultados do programa experimental não contrastaram muito com os disponíveis na literatura técnica. Observou-se que o fluxo eletro-osmótico é proporcional ao gradiente elétrico aplicado e que apresentava um comportamento errático durante o decorrer do ensaio,possivelmente devido às reações causadas pela eletrocinese. A variação no teor de umidade através dos corpos de provas foram ínfimas. Um fato curioso foi a indepedência dos parâmetros que avaliam a eficiência eletro-osmótica em relação ao gradiente elétrico aplicado.Em relação ao consumo energético, verificou-se que o mesmo é maior durante os instantes iniciais do ensaio e tende a se estabilizar com o passar do tempo. Observou-se ainda, uma relação direta com o gradiente elétrico aplicado. Para fins de projeto, o consumo enérgético pode ser estimado como US$ 0,30 por kW.h/m3. / [en] The present dissertation presents a laboratory study of electro-osmosis in a residual soil from gneiss. The objective of this study was to develop test equipment and methodology. Two different cells were constructed,one for natural and the other for reconstituted material. The experimental results are consistent with technical literature values. It was observed that the electro-osmotic flow is proportional to the magnitude of the eletrical potential gradient and shoewd a some what erratic behaviour during the test, which could be due to the physical- chemical reactions through the soil caused by electrolysis. The variation of water content in the specimens was minimal. One curious fact was that the electroosmotic efficiency coefficient, which evaluates the electroosmotic efficiency , turned out to be independent from the eletrical potential gradient. The power expenditure was greater during the initial stages of the tests and tended to stabilise over the remaining time.It was observed a direct relation between the power expenditure and the eletrical potential gradient. For design purposes, the current cost of energy expenditure could be assumed as U21730 0,30 per KW.h/m³. There is a little variation in the temperature of electrolytes during tests. It was also observed that eletroosmotic flow can be improved by acidification of the solution.

Thesis (Ph.D.(Chemistry))--University of Pretoria, 1992. / Includes abstract in English and Afrikaans. Includes bibliographical references.

Thesis (Ph. D.)--University of Alberta, 2010. / Title from pdf file main screen (viewed on July 8, 2010). A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Doctor of Philosophy, Department of Physics, University of Alberta. Includes bibliographical references.