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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.

Electrokinetic flow in micro- and nano-fluidic components

Zheng, Zhi, January 2003 (has links)
Thesis (Ph. D.)--Ohio State University, 2003. / Title from first page of PDF file. Document formatted into pages; contains xxix, 269 p.; also includes graphics (some col.). Includes abstract and vita. Advisor: A. Terry Conlisk, Biomedical Engineering Center. Includes bibliographical references (leaves 261-269).

Electrokinetic processes for microfluidic devices

Coleman, Jeffrey Thomas. 10 April 2008 (has links)
No description available.

The superoxide radical in the environment and electrokinetic charging in liquid micro-jets / Mark Tattersall.

Tattersall, Mark, 1973- January 2002 (has links)
"March 2002" / Includes bibliographical references. / xii, 178 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Examines the application of physico-chemical phenomena to aspects of environmental analysis. Measures the superoxide radical in natural waters in order to establish the role of the radical in natural water chemistry. Also investigates the electrokinetic charging behaviour associated with liquid microjets in order to understand the unusual charging behaviour reported in the literature with the ultimate goal of determining the viability of using the charging mechanism for in vacuo ion generation. / Thesis (Ph.D.)--University of Adelaide, Dept. of Chemistry, 2002

Enhancement of biomolecule binding on biosensors using AC electrokinetics /

Hart, Robert Weisbein. Noh, Hongseok (Moses). January 2010 (has links)
Thesis (Ph.D.)--Drexel University, 2010. / Includes abstract. Includes bibliographical references (leaves 165-171).

Breaking and curing rates in asphalt emulsions

Banerjee, Ambarish 30 January 2013 (has links)
This PhD dissertation addresses a number of issues pertaining to the use and application of surface treatments using asphalt emulsions. The work conducted as part of this research study shows in detail the problems associated with the state-of-practice and how these issues can be addressed using a scientific and rational approach as opposed to the experience-based approach which is prevailing currently. The first objective of this research study focuses on developing a methodology to determine the total amount of evaporative water loss of an emulsion before the aggregates are placed. An algorithm is presented that can be used by field inspectors and practitioners for the optimal timing of chip placement. The second objective focuses on another key aspect associated with the constructability of surface treatments, i.e., the optimal time to open a new surface treatment to traffic. Laboratory tests were conducted on the emulsion and aggregates to measure the rate of moisture loss and the evolution of the rheological properties as function of time. This was related to the field measured evaporation rates to determine the minimum stiffness required for optimal performance of the chip seal towards adequate resistance to raveling. The final objective of this dissertation focuses on developing a theoretical understanding of the current flowing through a circuit when an emulsion separates into its constituent phases when placed in an electric field. The measured current depends on a set of material properties that include the emulsion’s viscosity, surface potential, and dielectric of the medium and the strength of the electric field. A theoretical formulation was developed that relates the current flowing through the circuit with the mobility of the charged particles and the bulk charge density. The proposed theory was further utilized in developing a test procedure to quantify the breaking characteristics of asphalt emulsions. Results demonstrated that the parameters obtained from these tests were repeatable and different for different types of asphalt emulsions. It was also noticed that for a given type of emulsion the test method is sensitive to factors such as water content and partial breaking due to mechanical agitation. / text

Electrokinetic Structuring of Catalyst Layers for Polymer Electrolyte Fuel Cells

Hoidas, MARK 12 December 2011 (has links)
This thesis investigates the possibility of using electrokinetic effects, induced when a colloidal system is subjected to an electric field, to produce deterministic structure in the catalyst layer of polymer electrolyte membrane fuel cells. The susceptibility of the catalyst ink system to electrokinetic effects is clearly demonstrated. A novel apparatus and procedure is developed to allow for the formation of continuous films between two electrode surfaces through solvent evaporation. Characterization of the resulting layers is done through imaging and rotating disc electrode measurements. While the images show some possibility of structure formation, no clear increase in the oxygen reduction rate is observed. Recommendations for extending this work are provided. / Thesis (Master, Chemical Engineering) -- Queen's University, 2010-01-06 17:29:23.27

Electrokinetic Transport Process in Nanopores Generated on Cell Membrane during Electroporation

Movahed, Saeid January 2012 (has links)
In this thesis, underlying concepts of transport phenomena through generated nanopores on a cell membrane during electroporation were studied. A comprehensive literature review was performed to find the pros and cons of the previous works and consequently extensive studies were accomplished to explain shortcomings of the former studies on this topic. The membrane permeabilization of the single cell located in the microchannel was studied, and the effects of microchannel’s wall and electrode size were investigated on cell electroporation. It was studied how the electrical (e.g., strength of the electric pulse) and geometrical parameters (e.g., microchannel height and electrode size) affect size, location, and number of created hydrophilic pores on the cell membrane. Because of a transmembrane potential, the electrokinetic effects have decisive influence on the transport process through the created nanopores. A comprehensive study was performed to explain the electrokinetic transport through the nanochannels. Effects of surface electric charge and radius of the nanochannel on the electric potential, liquid flow, and ionic transport were investigated. Unlike microchannels, the electric potential field, ionic concentration field, and velocity field are strongly size-dependent in the nanochannels. They are also affected by the surface electric charge of the nanochannel. More counter ions than co-ions are transported through the nanochannel. The ionic concentration enrichment at the entrance and the exit of the nanochannel is completely evident from the simulation results. The study also shows that the fluid velocity in the nanochannel is higher when the surface electric charge is stronger, or the radius of the nanochannel is larger. The obtained model of the electrokinetic effects in the nanochannels was utilized to examine the ionic mass transfer and the fluid flow through the generated hydrophilic nanopores of the cell membrane during electroporation. The results showed how the electric potential, velocity field, and ionic concentration vary with the size and angular position of the generated nanopores of the cell membrane. It was also shown that, in the presence of the electric pulse, the electrokinetic effects (the electroosmosis and the electrophoresis) had significant influences on the ionic mass transfer through the nanopores, while the effect of diffusion on the ionic mass flux was negligible in comparison with the electrokinetics. Increasing the radius of the nanopores intensified the effect of convection (electroosmosis) in comparison with the electrophoresis on the ionic flux. Furthermore, the electrokinetic motion of the nanoparticle through the nanochannel was investigated to mimic inserting the nanoscale biological samples, such as QDots and DNAs, through the created nanopores on the cell membrane. It was proved that, because of the large applied electric field over the nanochannel, the impact of the Brownian force was negligible in comparison with the electrophoretic and the hydrodynamic forces. It was demonstrated that increasing the bulk ionic concentration or the surface charge of the nanochannel will increase the electroosmotic flow, and hence affect the particle’s motion. It was also shown that, unlike the microchannels with thin EDL, the change in the nanochannel size will change the EDL field and the ionic concentration field in the nanochannel, affecting the particle’s motion. If the nanochannel size is fixed, a larger particle will move faster than a smaller particle under the same conditions. Finally, it was examined how the nanoscale biological samples (nanoparticles) reach openings of the generated nanopores on the cell membrane during electroporation. It was examined what forces (electrophoresis, diffusion, and convection) brings the nanoparticles into the nanopores and how the size and the surface electric charge of the nanoparticle affect its transport to the opening of the nanopores.

The electrokinetics of porous colloidal particles /

Looker, Jason Richards. January 2006 (has links)
Thesis (Ph.D.)--University of Melbourne, Dept. of Mathematics and Statistics, 2006. / Typescript. Includes bibliographical references (leaves 169-181).

The characterization of cationic pseudostationary phases for electrokinetic chromatography

Schnee, Vincent Patrick. January 2007 (has links)
Thesis (Ph. D.)--University of Montana, 2007. / Title from title screen. Description based on contents viewed Aug. 13, 2008. Includes bibliographical references (p. 102-108).

Electrokinetic transport of a pure polar fluid through a channel

Shin, Yun Kyung. January 2008 (has links)
Thesis (M.S.)--Ohio State University, 2008. / Title from first page of PDF file. Includes bibliographical references (p. 48-51).

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