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 30 for “"Debye-length"”.
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Adsorption in Confined Aqueous Films
… was on the effect of the electrostatic screening length, or Debye-length. The separation was measured using interference microscopy and the adsorption of fluorescein was measured using fluorescence microscopy. The Debye-length was altered by variation of the background salt (NaCl) concentration in …
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Development of the DRACO ES-PIC code and Fully-Kinetic Simulation of Ion Beam Neutralization
… domain with cell size much greater than the Debye length resulted in a formation of a virtual anode. Decrease of the cell size to match the Debye length was not feasible, since it would require a million-fold increase in the number of simulation nodes. Instead, a scaling scheme was devised. …
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Two dimensional particle-in-cell simulation model for Hall type thrusters
… forward, the simulation size was 50x20 Debye lengths. Cell size was half of the plasma Debye length, in both dimensions. Time step was based on the condition that the electron gyroradius be ten times the Debye length, for a given electron temperature of 10 eV and maximum magnetic field …
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Enhancing retarding potential analyzer energy measurements with micro-aligned electrodes
… a system of grids with holes smaller than a few Debye length - a characteristic length proportional to the square root of the electron temperature divided by the electron number density. Thus, cold, dense plasmas have the smallest associated Debye lengths and require smaller grid openings than …
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Confinement of Non-neutral Plasmas in Stellarator Magnetic Surfaces
… experiment designed to create and study small Debye length non-neutral plasmas confined by magnetic surfaces. This thesis describes experimental confinement studies of non-neutral plasmas on magnetic surfaces in CNT. Open orbits exist in CNT resulting in electron loss rates that are much faster …
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Transport and Adsorption in Nanoscale Confinement
… layer model, where the characteristic decay length of the potential is the Debye length κ^(-1), which is typically 1–100 nm. In a nanoscale confinement, the electrostatic potential from both confining surfaces overlaps, and there is no bulk solution in the confined liquid. If the two surfaces …
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Overcoming barriers in chemistry : a birds eye view of electrostatic fluctuations in fundamental proteins and streamlining inclusivity in the classroom.
… charged protein crowders at a distance below the Debye length (≤ 7.9 Å) to determine how the net charge of the crowder affects the enzymatic activity of the enzyme. Chapter four is dedicated to a project that improves the inclusivity of the blind and visually impaired in the classroom by 3D …
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Batch-microfabricated miniaturized planar arrays of Langmuir probes for reentry plasma diagnostics and nanosatellites
… of the electron temperature, number density, and Debye length. The performance of the MEMS Langmuir probes as a triple probe was benchmarked using a homemade conventional triple Langmuir probe. The plasma parameters measured by the MEMS Langmuir probe were within the range of VTF's reported plasma …
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Fuel Efficient Control Design and Constrained Motion Analysis for Spacecraft Coulomb Formation in Elliptic Chief Orbits
… Due to the effects of plasma shielding, a Debye length model is incorporated in the nonlinear dynamics as a linear function of altitude of the formation's center of mass. The integrated thruster efforts are calculated for both optimal and analytical techniques and the fuel costs are …
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Impedance spectroscopy for cellular and biomolecular analysis
… in cavities of dimensions comparable to the Debye length.
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Conformation and Rheology of Semiflexible Macromolecules Using Non-Equilibrium Brownian Dynamics and Monte Carlo Simulations
… forces, and for polyelectrolytes a screened Debye-Huckel potential is also present. The Fokker-Planck equation describing this chain is converted to a Stochastic Differential Equation (SDE) from which the simulation algorithm for the NEBD is obtained. In steady, potential flows, the solution …
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Kinetic electron phenomena in dense magnetized plasma wakes
… obstacle by dense magnetized plasma, having both Debye-length and gyroradii smaller than the obstacle, is explored using particle-in-cell (PIC) simulations. These simulations are relevant to a wide range of physical settings, ranging from the moon in the (supersonic) solar wind to Mach probes in …
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The gridded electromagnet probe
… to be within a factor of ten of the electron Debye-length [lambda][sub]De. In addition, an analysis of the discrete structure of the grid showed that the mesh wire spacing d should be chosen to be much less than [lambda][sub]De. Also, the wire thickness t should be chosen to be much less than …
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Experimental Studies of Spacecraft Plasma Interactions: Facility Characterization and Initial Measurements
… probes used in the test facility Rs > Debye length and thus were analyzed under the thin sheath condition. The second measurement attempts to measure the 3-D plasma flow field for plasma flow over a structure composed of 4-inch biased Al box sitting on a biased Al plate. The results …
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Controlling the interfacial behaviour of colloidal microgel systems
… MgCl2, LaCl3) were used to reduce the particle Debye length. Conditions conducive to preserving stability or encouraging flocculation were identified and related to the complex balance of particle interactions. It is anticipated that the results of these investigations may support future …
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Development of electrode manipulated close-packed microplasma jet arrays in a transparent polymer
… microchannels with diameters ≤350 μm, and jet lengths up to ~4 mm when the He backing pressure is ~840 Torr. Driven by a 20 kHz sinusoidal ac voltage waveform, the operating voltages are as low as 1 kV rms. Arrays as large as 121 jets in a cross-sectional area of 100 mm2 and having excellent …
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Thermally Developing Electro-Osmotic Convection in Circular Microchannels
… by a voltage potential gradient along the length of the microtube, the hydrodynamics of such a flow dictate either a slug flow velocity profile (under conditions of large tube radius-to-Debye length ratio, a/lambda_d) or a family of electro-osmotic flow (EOF) velocity profiles that depend …
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Novel methods for fabrication of non-close-packed structures through colloidal self-assembly
… structures. Indeed, it is shown that at high Debye lengths, by varying the concentration of particles in a suspension of like-charged colloids, electrostatic repulsion among particles can stabilize "sparse" structures. In these structures, particles occupy only a few of the many sites that are …
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Kinetic Simulations of Spacecraft Charging and Plasma Interactions in the Solar Wind
… emissions where we set a free flyer at 2*Debye length behind the platform in the wake. For the particular system studied in this dissertation, the simulation shows that wake charging is not severe under both the mean solar wind condition and severe magnetosheath charging condition.
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Numerical Simulations in Electro-osmotic Flow
… generated flow with large channel diameter-to-Debye length ratios (Z). The physics of the flow field were compared between the moving wall model (MWM) and electro-osmotic flow (EOF) at Reynolds numbers of 1 and 1800, and Z > 2500. Also, Z-values between 50 and 500 were studied to investigate …
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