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.
Results
Showing 1 to 20 of 32 for “"spherical geometry"”.
-
Helical Antennas with Truncated Spherical Geometry
A new variation of the spherical helical antenna made of a wire wound over a hemispherical surface and backed by a conducting ground plane is introduced. A constant spacing is maintained between the turns of winding. The geometry of this antenna is fully described by the number of turns and the …
-
Thermionic emission parameters of tantalum single crystals in spherical geometry
La méthode de production de cristaux sphériques introduite par Monsieur H. F. Webster (13) fut modifiée. Ces modifications ont produit des cristaux ayant un système de chauffage amélioré. Un cristal de tantale fut fixé a l’intérieur d’un tube a projection qui fut développé pour permettre des …
-
First Flight Effects on Two-Group Thermal Diffusion Equations in Spherical Geometry
Made available in DSpace on 2017-07-06T18:48:55Z (GMT). No. of bitstreams: 3 Kastanes_John_MS.pdf: 38375200 bytes, checksum: cd6e29cd80cda3777cc1521ca8b143e0 (MD5) Kastanes_John_MS_ABS.pdf: 1047967 bytes, checksum: e788b2c7a1ebd2c56942fec58253a9d7 (MD5) license.txt: 4813 bytes, checksum: …
-
Biodegradable, Liquid-Filled, Spherical Capsules With Pre-Determined Burst Times
… acid) (PLGA) capsule is presented in a spherical geometry, which exploits the principle of osmosis as an internal program to achieve a delayed-burst release of its load. The capsule burst lag-time is accurately predicted by modeling the rate of water uptake by the capsule core as a …
-
Highly maneuverable spherical robots for underwater applications
… this work explores the design of new, spherical robots. There exist many benefits to the spherical geometry of vehicles. With zero added mass and identical dynamics moving in all directions, the maneuvering capabilities of these robots are extremely high, making them easy to control and …
-
PROBABILISTIC METHOD IN RADIATIVE TRANSFER AND NEUTRON TRANSPORT PROBLEMS
… capable of interpreting the transfer problems in spherical geometry. As the basic inspiration of the probabilistic method was drawn from Ambartzumian's physical method of principle of invariance, it has been thought worthwhile to examine the merits and limitations of all the methods whose origins …
-
X and Ultraviolet Radiation From Accreting Non-Magnetic Degenerate Dwarfs: A Two-Fluid Treatment of the Emission Region and the Effects of Steady Nuclear Burning
… thermal conduction. The calculation is done in spherical^geometry, with cooling by bremsstrahlung and cooling by the inverse^Compton effect added in the post shock emission region. Our two-fluid^calculations are needed only in the small region bounded by M(, )>(, )1.2^M(,(CIRCLE)) and M(, )>(, …
-
Constraints on mantle convection from seismic tomography and flow modeling
… of modeling buoyancy driven mantle flow in spherical geometry. Here, the linear Stokes equation is solved using a Green's function approach and 3-D surfaces, representing the boundaries of dense material, such as subducting slabs, are tracked through time.
-
On the Spectrum of Neutron Transport Equations with Reflecting Boundary Conditions
… conditions. Two typical geometries --- slab geometry and spherical geometry --- are considered in the setting of <I>L^p</I> including <I>L^1</I>. Some aspects of the spectral properties of the transport operator <I>A</I> and the strongly continuous semigroup <I>T(t)</I> generated by <I>A</I> …
-
Monte Carlo study of pebble bed reactor fuel reactivity and isotopics
… various levels of simplification for the actual spherical geometry as well as the equivalent cylindrical geometry, to test their ability to reproduce results described in several published reports. These models were then used to calculate reactivity, spectral indices, and bumup isotopics for a …
-
Theoretical performance analysis of a novel hemispherical tissue equivalent proportional counter for neutron monitoring and dosimetry
… audible noise. This work proposes a novel hemispherical element with a wire-less anode ball as a solution. The hemispherical METEPC element was analyzed as a single TEPC to first demonstrate the potential of this new design. Its performance was evaluated relative to current cylindrical and …
-
Turbulent convection in the anelastic rotating sphere : a model for the circulation on the giant planets
… dynamics of a whole sphere of gas rather than a spherical shell (including the strong variations in gravity and the equation of state). Different from most previous 3D convection models, this model is anelastic rather than Boussinesq and thereby incorporates the full density variation of the …
-
Simple Physical Approaches to Complex Biological Systems
… of any size biomolecule is derived using spherical geometry. The solution is tested both on an ideal sphere relative to an exact solution and on a multitude of biomolecules relative to a numerical solution. In all cases, the bulk of the error is within thermal noise. The computational …
-
The Influence of Curvature on Mantle Convection featuring a Temperature-dependent Viscosity
… convection regime is first examined in 2D and 3D spherical geometry with varying mantle curvature (core-to-surface radii-ratio, f) and constant heating conditions and viscosity contrast across the mantle depth (ΔηT). The onset of the stagnant-lid regime occurs for different conditions for bodies …
-
Spatio–temporal analysis of changes of shape for constituent bodies within biomolecular aggregates
… to describe the spatial dependences in a spherical geometry. Both models also describe the effect of time-dependent boundary data on the shape of the bodies involved, a stochastic response for the enzyme model (dimensions of the order 10−9 m) and smooth response for the colloidal model …
-
From self-assembly to communications via machine washable fibers
… uniformly sized and uniformly structured spherical particles internal to the fibers. Judicial choice of the materials and control over the kinetics of this process allowed to integrate the spherical particles into an active fiber device. We have introduced additional ability to control the …
-
Effective thermal conductivity of binary mixed materials with fissile components - an empirical approach
… was carried out for a steady state problem with spherical geometry to develop an expression for the effective thermal conductivity for the spherical pebble fuel in a pebble bed reactor. The approach is based on two main concepts: a structural approximation and an empirical formulation. As for the …
-
Turbulent convection in an anelastic rotating sphere : a model for the circulation on the giant planets
… dynamics of a whole sphere of gas rather than a spherical shell (including the strong variations in gravity and the equation of state). Different from most previous 3D convection models, this model is anelastic rather than Boussinesq and thereby incorporates the full density variation of the …
-
Processing and protection of rare earth permanent magnet particulate for bonded magnet applications
… was eliminated in bonded magnet fabrication. The spherical geometry of HPGA powders is more ideal for processing of bonded permanent magnets since higher loading fractions can be obtained during compression and injection molding. This increased volume loading of spherical PM powder can be …
-
Theoretical prediction of drug release in GI tract from spherical matrix systems
… into account the affect of absorption rate. Spherical geometry of the particles is considered. The model is developed by assuming that the drug is release into a finite volume and is thereby absorbed through the intestine wall following first order kinetics. A closed form solution is obtained …
Page 1 of 2