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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 25 for “"axial symmetry"”.
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Axial symmetry and transverse trace-free tensors in numerical relativity
… task however. Assuming the added condition of axial symmetry, expressions are given in both spherical and cylindrical coordinates, for TT tensors in flat space. A coordinate relation is then calculated between the scalar potentials of each coordinate system. This is extended to a non-flat …
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Star formation in the presence of magnetic fields: Molecular cloud core formation and dynamical contraction due to ambipolar diffusion; a simulation with axial symmetry
Interstellar molecular clouds are generally believed to be the sites of active star formation in our galaxy. Observed densities, temperatures, and magnetic field strengths imply that well-ordered magnetic fields dominate thermal pressure in supporting these objects against self-gravity. The …
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Electron paramagnetic resonance analysis of dimethyl amidogen in polycrystalline tetramethyl tetrazene.
… line shape analysis. The radical exhibits axial symmetry with the parallel components of the tensors greater than the perpendicular components. The limits of error associated with the components of the tensors were estimated from the general comparison of the calculated and observed spectra.
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The Effect of the 2-Dimensional Magnetic Field Profile in Hall Thrusters
… using a simple, two-dimensional model, assuming axial symmetry. The previous one-dimensional conclusion, namely that the details of the shape of the magnetic field are unimportant, was confirmed. This result has implications for the design of future Hall thruster engines, with an eye toward …
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Resolving optical illumination distributions along an axially symmetric photodetecting fiber
… devices display a continuous translational symmetry which presents challenges to the extraction of spatially resolved information. In this thesis, we overcome this seemingly fundamental limitation and achieve the detection and spatial localization of a single incident optical beam at …
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A nuclear magnetic resonance study of UNI₂AL₃
… shift has been examined for the case of non-axial symmetry. A detailed derivation is given, correct to second order in perturbation theory, for the case where the quadrupole interaction is significantly smaller than the Zeeman interaction. These results have been applied to the study of the …
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A programming approach to the numerical analysis of elasto-plastic continua
… for problems in plane stress, plane strain or axial symmetry, using triangular constant strain finite elements, and is extended to the use of cubic quadrilateral isoparametric elements for which a numerical integration technique is employed to account for elasto-plastic interfaces within …
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A programming approach to the numerical analysis of elasto-plastic continua
… for problems in plane stress, plane strain or axial symmetry, using triangular constant strain finite elements, and is extended to the use of cubic quadrilateral isoparametric elements for which a numerical integration technique is employed to account for elasto-plastic interfaces within …
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Paramagnetic resonance of transition group ions in crystals with the fluorite structure
… helium temperature. The trigonal spectra have an axial symmetry about a (lll) direction with g11 = 2.25 +/- 0.05 and g1 = 4.45 +/- 0.10. The origin of this trigonal center is unknown. The isotropic spectra can be described by a spin Hamiltonian with g = 2.32 +/- 0.01, u=-0.Oil +/- 0.004, A = 27.5 …
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Oppenheimer-Snyder Collapse in the BSSN Formalism
… relativity, problems with high degrees of symmetry often serve as illustrative simplifications of complicated scenarios. Oppenheimer-Snyder collapse, an exact solution for the gravitational collapse of a uniform, pressure-less ball of dust into a black hole, provides valuable insight into …
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Surface discharge dynamics: theory, experiment and simulation
… into two phases. The first phase involves the axial streamer development in the gas gap between the needle electrode and the dielectric surface. This phase is simulated in 2D axial symmetry space dimension by the finite element package COM-SOL. The second phase simulates the streamer …
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Formability of Sheet Metal Under Non-Coaxial and Zig Zag Strain Paths
… drawing, the deformation in the work-piece is coaxial owing to axial symmetry; in other words, during the forming operation, the principal axes of stress and strain coincide with each other and are fixed with respect to the material. The directions of the principal axes are along the meridional …
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Three-Dimensional Single Particle Tracking on the Two -Photon Microscope
… into the optical system that break the axial symmetry of the point spread function and serves as an indicator of the particle's axial position. We identified several different modes of motion in sucrose solutions and agarose gels, including the transient trapping of particles in the …
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Engineering Biomedical and Bioinspired Fiber Devices via Thermal Drawing
… multimaterial fibers which have breaking axial symmetry within them. Microscale patterns along the shaft enable the functional point for biomedical devices to be extended from the tip to all surfaces by customizably exposing internal functionalities of multifunctional fibers. Second, …
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Mössbauer and EPR studies of iron-containing proteins
… Rd have fine structure parameters of rhombic symmetry. has an exceptionally slow spin-lattice relaxation, which is dominated by direct processes up. to 150K. We have studied HRP in the native state and as the reaction intermediates, compounds (1) and (11). The spin Hamiltonian of the high-spin …
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Rotational locks for gravity gradient satellites
… properties and orbital eccentricity. For nearly axial symmetric satellites, the maximum and minimum instantaneous rates which permit the satellite to remain in a particular rotational lock are found analytically by applying the averaging techniques of Kryloff and Bogolinboff and that of Symon. …
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Optical Fiber Microstructures for Self-Contained Whispering Gallery Mode Excitation
… the most effective of optical resonators show axial symmetry in at least one dimension. A popular variation that finds broad application is the dielectric sphere. Acclaimed for their high quality (Q) factor and small modal volume, spheres owe credit of these attractive features to their support …
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Magnetic vector potential based formulation and computation of nonlinear three dimensional magnetostatic fields and forces in electrical devices by finite elements
… are inherently two dimensional in nature due to axial symmetry. This result provides a further verification of the validity of the three dimensional finite element formulation presented in this work.
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Optimally-robust nonlinear control of a class of robotic underwater vehicles
… by high fineness ratios (length-to-diameter), axial symmetry, and passive roll stability. These vehicles are optimized for robotic applications needing power efficiency for long-range autonomous operations and motion stability for sensor performance improvement. A familiar example is the REMUS …
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A magnetic resonance study of the screening of electric fields in metals
… gradients, viz. 122 kc/sec and 61 kc/sec for axial symmetry. No other clearly discernable resonance was observed between 54 kc/sec and 150 kc/sec. Work of T. J. Rowland sets an upper limit of about 185 kc/sec for the pure quadrupole resonance of aluminum in the largest field gradient near to …
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