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 67 for “"Gravitational field"”.
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Notes on generalized Fourier series with application to gravitational field determination
Let{(}φ<sub>n</sub>(x)} be an orthonormal system in the set of Lebesgue square integrable functions L². Let f𝜖L². The generalized Fourier series of f with respect to {(}φ<sub>n</sub>(x)} is the series ∑<sub>n=0</sub><sup>∞</sup> (f, φ<sub>n</sub>) φ<sub>n</sub>(x), where (f, φ<sub>n</sub>) is the …
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Forward modeling the gravitational field using a direct solution of Poisson's equation
… of gravity data typically computes the vertical gravitational acceleration using either closed-form formulae, or numerical solution of Poisson's equation governing the gravity potential followed by numerical differentiation. We present a method for computing the vertical gravity anomaly directly …
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Lunar gravitational field estimation and the effects of mismodeling upon lunar satellite orbit prediction
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1993.
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Position control and vibration suppression of a flexible beam-like structure cantilevered from a rotary actuator within a gravitational field
… control of beam-like structures within a gravity field using only root actuation was performed. Two methods were used to linearize the system's equations of motion. This, in turn, allowed for the use of powerful Modern Control Theory pole-location techniques to determine proper feedback-control …
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The gravitational field in a fluid sphere of uniform invariant density according, to the theory of relativity ; Note on de Sitter ̕Universe ; Note on the theory of pulsating stars
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Physics, 1927.
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Gravitational microlensing and the search for extrasolar planets
This project is aimed at tackling binary gravitational microlensing events. Since the early conception of gravitational lensing before Einstein’s General Theory of Relativity, physicists and astronomers of the early 18th century speculated that light, if treated as particle, can be affected by …
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Gravitational waves: understanding black holes
This thesis concerns the use of observations of gravitational waves as tools for astronomy and fundamental physics. Gravitational waves are small ripples in spacetime produced by rapidly accelerating masses; their existence has been predicted for almost 100 years, but the first direct evidence of …
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Microgravity measurement in space using imaging techniques.
The proposal is made that very small changes in gravitational field could be detected by monitoring a cell of heated fluid. Variations in gravity would be observed by their effect on the convection in the fluid cell. It is proposed that the convection patterns be observed by using an interferometer …
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The Uniform Hanging Cable as a Translational Vibration Absorber.
… of a uniform cable suspended from a mass in a gravitational field and having a lower end mass are considered in this thesis. The frequencies and modal configurations for free vibration were determined. Secondly, a harmonically varying forcing function was applied to the upper mass for the …
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Applications of Hodograph Transformation to Hydrodynamic Problems Influenced by Gravitation
… found that even with strong influence of the gravitational field, the stream function can be solved in the hodograph plane through numerical calculations. The velocity function of free streamlines must be determined through iterations and it has been also found that this iterative process is …
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The motion of a lunar satellite under the influence of the moons noncentral force field
… disturbing force due to the moon's noncentral gravitational field which, unlike the earth's field, is unsymmetrical and rotating. This thesis presents a first-order approximation to the motion of lunar satellites under the forces resulting from this field. The results are a set of equations …
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Novel Derivations of the Metric from the Newtonian Potential and of the Relativistic Quantum Equation
… metric could represent an electromagnetic field as well as a gravitational field. I unify the two fields of electromagnetism and gravity into one symmetric metric. In the second part of this thesis, I derive a novel relativistic quantum equation. The operators are derived, and the …
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Optimal cooperative power-limited rendezvous
… Total propellant consumption is minimized. Two gravitational field models are investigated: the Clohessy-Wiltshire linearized field and the inverse-square field. Analytical solutions are obtained for the linearized gravity field. A direct method using direct collocation with nonlinear …
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Shear-free perfect fluid theorems in general relativity
… to establish the consistency of the Einstein gravitational field equations under the barotropic shear-free perfect fluid condition. Using a Mathematica package xTensor, we were able to prove the following cases: the case where the pressure is constant, the acceleration vector is parallel to …
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Determination of coefficient of storage by use of gravity measurements.
… a water-table aquifer by correlating change in gravitational field intensity with change in groundwater storage. In theory, this purpose may be accomplished by modifying the Bouguer slab equation to coefficient of storage equals 78.3 times the ratio of change in gravity in milligals to change in …
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Cooperative Power-Limited Optimal Rendezvous Between Many Spacecraft
… rendezvous problem of several spacecraft. The gravitational field models investigated are the Clohessy-Wiltshire field and the inverse-square gravity field. Numerical solutions using a shooting method and the finite difference method are used in order to determine the trajectories of the …
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Existence and stability of stellardynamic models
… evolution is determined by the self-consistent gravitational field which is created by the particles, e.g. the stars . In the first part we examine steady states which decsribe static shells under the influence of a fixed point mass. These solutions can be used as a model for a galaxy with a …
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Método dos Elementos de Contorno para elasticidade linear bidimensional
… only. For body forces arising from a fixed gravitational field, two formulations are utilized for transforming the domain integrals into boundary integrals. A formulation which can consider a domain divided into aligned sub-regions is derived. Some applications are performed in order to …
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A study of nucleate boiling in an accelerated system
… pressure. Teats were made under standard gravitational acceleration and under 2.85 times the standard gravitational acceleration. Chromel A electrical resistance wire, 0.008 inch in diameter, served as the heat transfer area. Acceleration of the system was obtained by use of the centrifuge …
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