Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 110 for “"Concentration Gradient"”.
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Fluoride varnish concentration gradient effects measured by quantitative light fluorescence
… study was four-fold: 1) to measure the fluoride concentration gradient in 10-ml tubes of fluoride varnish, based on the resting position of the tube prior to use; 2 ) to compare a varnish 's concentration gradient to its ability to inhibit caries in an artificial caries environment; 3) to compare …
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Microfluidic Concentration Gradient Generation and Integrated Magnetic Sorting of Microparticles
… stimulation of cells, rapid and novel designs of concentration gradient generation (CGG) devices are presented; for cell sorting, a magnetically The most prevalent type of CGG devices, i.e., complete mixing-based laminar-flow CGG devices, involves massive channel networks. The design of …
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Vertical Concentration Gradient of Influenza Viruses Resuspended from Floor Dust
… This research focuses on predicting the concentration of influenza A viruses in resuspended dust, generated by people walking in a room, at various heights above the floor. Using a sonic anemometer, we measured the velocity field from floor to ceiling at 10-cm intervals to estimate the …
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CFD analysis of three-dimensional thermalhydraulics flow effects on wall concentration gradient profiles for Lbe loop fittings
… effects of thermalhydraulics flows on the wall concentration gradient profiles in LBE loop fittings. To that end detailed models of the fittings have been constructed to study these effects. These fittings include sudden expansion, sudden contraction, t-joint and elbow. The typical flow rates …
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Effects of Thickness, Morphology and Molecular Structure of Donor and Acceptor Layers in Thermally Interdiffused Polymer Photovoltaics
An in-depth study of concentration gradients in thermally-interdiffused polymer – fullerene photovoltaic devices, with a focus on thickness and heat treatments, is presented in this thesis. Device performance is improved from the bilayer by the creation of a concentration gradient of the donor and …
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Chemotaxis of Sperm Cells
… beat of their flagellum. In the presence of a concentration gradient of a chemoattractant, they can steer upwards the concentration gradient, a process called chemotaxis. Eggs release chemoattractants to guide the sperm cells to the egg. Sperm chemotaxis is best studied experimentally in the …
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Dual Spin-Cast Thermally Interdiffused Polymeric Photovoltaic Devices
… of the performance of thermally interdiffused concentration gradient polymer photovoltaic devices is carried out with particular attention to the effect of the thickness and the thermal treatments on the power conversion efficiency, short circuit current, open circuit voltage and other key …
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Assessing landscape and seasonal controls on CO2 fluxes in a karst sinkhole
… plane (i.e., depths of local maximum CO2 concentrations), analyze the distributions of concentration gradients, and investigate the validity of a uniform concentration gradient throughout the profile; and 2) assess the influences of vertical position and seasonality on CO2 fluxes within …
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Advances in biophysical methods for protein detection and characterisation
… sizing uses a microfluidic chip to create a concentration gradient. The protein diffusion coefficient is extracted from the time evolution of this gradient. Second, the diffusiophoretic coefficient of the protein can be extracted by diffusiophoresis, which is the motion of proteins driven by …
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Colloidal phoretic motion
… to the transport of particles up or down the concentration gradient of a different solute and can be exploited to control particle motion. This thesis seeks to understand the relative importance of different phoretic effects. It examines phoretic motion in the context of concentration …
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Electrical Resistance Studies of Hydrogen Diffusion and of Hydride Precipitation in Niobium
… studied by using thermotransport to establish a concentration gradient in a periodic width modulated sample. A sensitive Kelvin double bridge allowed the kinetics of return to uniform concentration to be monitored. In undeformed Nb, the Arhennius plot exhibited a curvature, in agreement with …
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Investigation of Neutrophil-Like HL-60 Cell Migration in a 3D Collagen Matrix
… to the tissue and follow the chemoattractant concentration gradient to locate and eliminate the invading pathogens. Understanding the patterns and mechanism of neutrophil migration in the presence of chemoattractants could possibly play an important role in discovering new treatments for …
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Interplay between interkinetic nuclear migration and cell fate determination in the developing zebrafish retina
… IKNM as a diffusive process across a nuclear concentration gradient generated by the addition of new nuclei at the apical surface. This analytical model is based on the observed stochastic basal movements of the nuclei during IKNM and produces a diffusion constant in line with those previously …
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Electrochemical shock : mechanical degradation of ion-intercalation materials
… ion-intercalation mate- rials are identified: 1) concentration-gradient stresses which arise during fast cycling, 2) two- phase coherency stresses which arise during first-order phase-transformations, and 3) inter-granular compatibility stresses in anisotropic polycrystalline materials. While …
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Roles of Interfacial Reaction on Mechanical Properties of Solder Interfaces
… with Ni. It was found that Bi developed a concentration gradient in the Ni 3Sn4 during interfacial reaction, with the Bi concentration falling off to zero as the Ni/IMC interface was approached. Therefore, the inhibition of Bi segregation by Ni was due to the inability of Bi to reach Ni/IMC …
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Non-Equilibrium Transport Across Liquid Membranes Using Coordination Cages
… from equilibrium, utilizing light and chemical gradients. The first system investigates o-fluoroazobenzene (FAB) in bulk liquid membranes, analogous to the Maxwell’s Demon thought experiment. Light irradiation drives directional transport of FAB away from its initial equilibrium. Introducing a …
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Modeling stress accelerated grain boundary oxidation (SAGBO) in INCOLOY alloy 908
… grain boundary due to oxygen diffusion with the concentration gradient and the stress field ahead of the crack tip as the driving forces. As oxygen forms brittle phases with the segregates in the grain boundary, it reduces the cohesive strength of the grain boundary and causes intergranular …
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Electrochemical facilitated transport: a study in synthesis, simulation and experimentation
… both with and against (downhill and uphill) its concentration gradient. Experimental results are presented for the movement of silver perchlorate and thallium chloride across methylene chloride bulk liquid membranes using 2,5,8,11,14,17,20-heptaoxa[21](1,1’)ferrocenophane-1,21-dione as the …
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Oscillatory Flow As A Means Of Enhanced Species Separation: A Three Dimensional Time-accurate Cfd Analysis
… fluid that contains species in the presence of a concentration gradient generates unusual phenomena when it is forced into pulsatile motion. For example, each species in the fluid has an enhanced mass transport due to pure molecular diffusion. This enhancement takes place even if there is no net …
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Studies on the characterization of a soluble factor of a sodium-activated, magnesium-dependent adenosinetriphosphatase in rat cerebral cortex
… ions across the cell membrane, this infers a concentration gradient of these ions. This differential distribution is important for certain life processes, for example, the propagation of nervous impulses mainly is dependent on the changes in concentration of sodium and potassium ions on both …
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