Engineering Commons^™

The Abel Inversion Of Noisy Data Using Discrete Integral Transforms, Subramania I. Sudharsanan

Masters Theses

The determination of a radially symmetric two-dimensional function from its one dimensional projection is known as Abel inversion. This finds applications in several fields of engineering and science including astronomy, image processing, plasma diagnostics and optics. One radial slice of the function, which completely specifies the two-dimensional function, is the inverse Hankel transform of the Fourier Transform of the projection. With the projection data available as a discrete signal, the Abel inversion can be performed using the discrete Fourier transform and the inverse Hankel transform. The existing techniques to compute inverse Hankel transforms are discussed and a modification to one …

Characterization Of The Rheological, Optical, And Flow-Induced Structural Features Of Polymer Liquid Crystals, David Neal Lewis

Doctoral Dissertations

Two related sets of experiments were conducted to explore the interaction between supramolecular structures, material properties, and flow-induced stresses in selected lyotropic and thermotropic polymers. The first set of experiments focused on the quiescent and rheological characterization of polymers. The objective was to develop a flow-structure model based on the general phenomenological features of the liquid crystalline state. The second set of experiments concerned the characterization of the crystal structure, crystalline orientation, and tensile properties of a model thermotropic polymer, melt spun under varying conditions of extrusion rate, extrusion temperature, drawdown ratio, and die exit conditions. The objective was to …

The Effect Of Particle Dynamics On Turbulence Measurements With The Laser Doppler Velocimeter, Robert H. Nichols

Doctoral Dissertations

The laser velocimeter (LV) is currently being used by many researchers to nonintrusively obtain velocity data in complex flow fields. The LV measures the velocity of small particles entrained in the flow field of interest. The fluid velocity and turbulent velocity correlations are then inferred from statistical analysis of these particle velocity measurements under the assumption that the particles exactly reproduce the motion of the fluid. This assumption needs careful evaluation since it is fundamental to the application of the LV.

The particle equation of motion was carefully analyzed to determine what form is required for evaluating the turbulence response …

Predictive Model For The Pulse Pressure In A Pulse-Jet Fabric Filter, Satoru Mitsutomi

Doctoral Dissertations

Pulse-jet cleaned fabric filters are being utilized to filter dust from particulate laden gas streams. The pulse-jet fabric filter consists of a reservoir, a solenoid valve, a lateral pipe and a venturi/bag. The compressed air is released periodically through a solenoid valve and fills the lateral pipe. Then high velocity air is ejected from a series of orifices on the lateral pipe. As a result, the bag is rapidly inflated and dust is dislodged from the bag.

A predictive model for the pulse pressure in a pulse-jet fabric filter has been developed. Two types of models are presented: Simplified Static …

Comparative Gene Mapping In Baboon (Papio) Species, Kathleen Lou Moore Thiessen

Doctoral Dissertations

Gene mapping in nonhuman mammalian species is a field of increasing importance in man's efforts to understand genome organization, to develop animal models for human genetic diseases, and to investigate phylogenetic relationships and evolutionary mechanisms. The primates are of particular interest in these studies because of their morphological and physiological similarities to man. The availability and convenient size of the baboons (Papio species) make them the primates of choice for various areas of research having applications to man. The baboons also appear to have many chromosomal and genetic homologies to man as well as to the other primates, although …

Determination And Interpretation Of Dispersion Of Small Particles In Thermoplastics, Yoshiyuki Suetsugu

Doctoral Dissertations

It is the purpose of the present research to characterize the particulate structure in the compounds for a range of small solid particulates. These include a wide range of calcium carbonates both in uncoated and coated modes, carbon blacks, uncoated and coated talc, mica, etc. The matrix polymers used are polystyrene and polypropylene.

The present research involves (i) development of methods and the interpretation of them to characterize the state of particles and their structure in plastics, (ii) to determine how these particulate structures are developed in the mixing process.

The primary particulate structure of concern is the state of …

Development And Applicability Of A Mathematical Model For The High Speed Melt Spinning Of Crystallizable Polymers, Kenneth F. Zieminski

Doctoral Dissertations

A mathematical model was developed to describe the high speed melt spinning behavior of crystallizable polymers. This model included the effects of acceleration, gravity and friction on the kinematics of the process, temperature and molecular orientation on the crystallization kinetics of the polymer and temperature, molecular weight and crystallinity on the elongational viscosity of the material. Experimental online diameter, birefringence and temperature profiles were obtained for a 12000 Mn nylon-66 at 2.5 gm/min spun at take-up speeds ranging from 2800 to 6600 meters/minute. These profiles were qualitatively and reasonably quantitatively in agreement with the predicted profiles. They indicated that orientation …

Production Test Station Networking And Collection Of Test Results, Dennis Wallace Matheson

Masters Theses

This thesis describes the installation of a network for all of the final test stations at the Industrial Systems Division of Texas Instruments in Johnson City, Tennessee. Once the network was installed, the project focused on the automatic collection of the test parameters for a centrallized database. The database was used to generate statistical data to determine if the manufacturing process were in control. If the process were not in control, then appropriate action was taken to prevent the particular unit from being tested. This provided a accurate and real-time analysis of how the manufacturing process was performing. Also, the …

Transient Response Of A Packed Bed For Both Sensible And Latent Thermal Energy Storage, Shi-Hong Ji

Doctoral Dissertations

The present work was undertaken to provide a model which accurately predicts the performance of a packed bed energy storage system utilizing spherically encapsulated phase-change material (PCM). Two models were developed which are referred to as the first-order and second-order models. Both models involve modeling of the phase-change material as a conduction problem with both sensible and latent energy storage and include consideration of the temperature gradients in both phases. Both models include the solution of the energy equation for the fluid passing through the packed bed. In the second-order model, both the intra-particle conduction and the dispersion effects in …