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Showing 1 to 20 of 26 for “"collision frequency"”.
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1S-2S spectroscopy of trapped hydrogen : the cold collision frequency shift and studies of BEC
Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Physics, 1999.
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Discontinuous Galerkin Studies of Collisional Dynamics in Continuum-Kinetic Plasma
Numerical investigations of collisional physics have historically been impeded by the issue of computational expense. While the continuum-kinetic Vlasov-Maxwell-Fokker-Planck system is well-established in theory and has been used as the basis for many approximate fluid equations, simulations …
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Artificial heating of the lower ionosphere
… is deposited in the ionosphere as a result of collisions of the electrons with the neutral molecules. Cross-modulation experiments (performed elsewhere) have gained information on electron number density and collision frequency between 60 and 90 km. The experiment described here will possibly …
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High Pressure Nmr Studies of the Dynamic Structure of Liquids
… of the transmission coefficient upon the collision frequency, which in the absence of electrostatic effects reflects the actual coupling of the reaction coordinate to the surrounding medium. In classical transition state theory the transmission coefficient is assumed to be unity and …
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Studies of Phase Inversion and Ambivalence in Liquid-Liquid Systems.
… of phase inversion. The model is based on the collision frequency and coalescence frequency of agitated dispersions in conjunction with models relating drop sizes and hold-up to agitator speed. Experimental investigations were made into ambivalent phase inversion in a batch and continuous …
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INVESTIGATION OF RESISTIVE GEODESIC ACOUSTIC MODE IN THE EDGE OF STOR-M TOKAMAK
… expression is obtained for the resistive GAM frequency. This theory suggests a large collision frequency will prohibit the parallel current in tokamak, which establishes the cross-field charge neutrality condition ∇·J⊥= 0 for the existence of GAM at the edge plasma of tokamak. Therefore, the …
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Development of a Flotation Rate Equation from First Principles under Turbulent Flow Conditions
… detachment, and froth recovery as well as a collision frequency. A review of the effects fluids have on the flotation process has also been given. This includes collision frequencies, attachment and detachment energies, and how the energies of the turbulent system relate to them. Flotation …
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Investigating the Effects of Urban Features on Bird Window Collisions
… of anthropogenic causes of mortality, including collisions into reflective glass windows. Annual avian mortality rate, surrounding landscaping, and building characteristics that can potentially predict mortality rate were evaluated on mid-rises on the York University Keele Campus. I predicted …
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An experimental investigation of the Buneman instability
… heating and an anomalously high electron-ion collision frequency are also observed. However, the Buneman frequency is not observed. Following the collapse of the current, strong oscillations near the ion plasma frequency are detected. Most of the experimental results are in qualitative …
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Optical Processes in Xenon: Multiphoton Ionization and Ultraviolet Photodissociation of the Dimer Ion
… peak electron densities. The electron-neutral collision frequency, (nu)(,m), has been obtained using a microwave bridge and the result is consistent with 0.7 eV electrons. It is found that when an ArF and an XeF excimer laser are fired simultaneously, the electron density is enhanced by at …
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On the Spectrum of Neutron Transport Equations with Reflecting Boundary Conditions
… is the essential infimum of the total collision frequency. The spectrum of <I>T(t)</I> outside the disk {lambda : |lambda| leq exp (-lambda^{ast} t)} consists of isolated eigenvalues of <I>T(t)</I> with finite algebraic multiplicity, and the accumulation points of sigma (T(t)) igcap{ …
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Implementation of Microwave Transmissions for Rocket Exhaust Plume Diagnostics
… propagation constant. Estimated values of the collision frequency and electron number density generated from a numerical simulation of a rocket plume are used to guide the design of the experimental apparatus. Test par meters are identified for the apparatus designed to transmit a signal sweep …
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Development of safety performance functions and a GIS based spatial analysis of collision data for the City of Saskatoon
… SPFs are mathematical equations that relate the collision frequency at a particular location with traffic volume and roadway characteristics. The purpose of this research is to develop a series of locally derived SPFs for the City of Saskatoon to allow engineers to estimate the expected number of …
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Experimental Investigation of Micro-Channel Blockage Phenomena
… in the micro-channels indicate that collision of particles against the channel wall increases the collision rate of particles. For the inlet flow, collision frequency and angle are determined by the angle of contraction.
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Two dimensional particle-in-cell simulation model for Hall type thrusters
… thruster configurations. The model used a non-collisional, two dimensional in regular space and three dimensional in phase space, particle-in-cell (PIC) formulation for simulation of the plasma, while a separate model accounted for particle collisions, using Argon-electron elastic, excitation …
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The Design, development, and analysis of a wearable, multi-modal information presentation device to aid astronauts in obstacle avoidance during surface exploration
… increasing navigation workload and risk of collision associated with traversing through unfamiliar terrain. Due to the hazardous nature of this work, there is a critical need to design interfaces for optimizing task performance and minimizing risks; in particular, an information presentation …
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Sistemi e dispositivi meccanici applicati a processi fisici e chimici
… metallurgy technique based on the occurrence of collisions between milling tools inside a reactor. At each collision, a fraction of the powder charge inside the reactor is trapped between colliding surfaces and submitted to a mechanical load. This induces cold-welding, fracturing and plastic …
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Coagulation between fractal aggregates and small particles and fractal properties of marine particles
… and small (1.48 μm) particles were studied for collisions induced by differential sedimentation and turbulent fluid shear. The collision frequency functions (beta) between these aggregates and small particles were found to be lower than predicted by a rectilinear collision model but much higher …
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Theoretical studies of the mid-latitude ionosphere
… of thermal diffusion. The importance of 0++ - 0+ collision frequency is also noted. In Chapter VI we extend the work of Chapter IV, presenting a comparative study of H and He at sunspot minimum and sunspot maximum.In this last Chapter all three ions, O+ ,H+ and He+ , are treated theoretically as …
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