Engineering Commons^™

Development Of A Parametric Analysis Microcomputer Model For Evaluating The Thermodynamic Performance Of A Reciprocating Brayton Cycle Engine, Thomas Joseph White

Dissertations and Theses

In this thesis, applicable data from research on IC engines have been adapted to PACE engine designs. Data from studies on heat transfer, friction, and pressure losses, in particular, have been used. Certain parameters which define operation and design characteristics appear to influence PACE engine performance very strongly. Some of the more critical parameters, notably friction and heat transfer coefficients, must be determined experimentally if accurate model results are to be expected. Pressure ratio, compressor RPM, and maximum combustor temperature, the independent operating parameters, also have a dramatic effect on engine performance. Other design or operating characteristics and working fluid …

A Finite Difference Soil-Structure Interaction Study Of A Section Of The Bonneville Navigation Lock Buttress Diaphragm Wall Utilizing Pressuremeter Test Results, Thomas C. Mccormack

Dissertations and Theses

The P-y curve, used in current practice as an efficient Iine-load vs. soi displacement model for input into the finite difference method of laterally loaded pile analysis, is extended in this study for use with cohesionless soils in diaphragm wall analysis on the Personal Computer with the BMCOL7 program. An analogous W-y curve is proposed, an elastic-plastic model with line-load limits developed from classical earth-pressure theories.

A new formula for predicting a horizontal walI modulus for cohesionless soiIs from the pressuremeter modulus is developed for use in predicting the displacements on the W-y curves. The resulting modulus values are shown …

Numerical Solutions Of Continuous Wave Beam In Nonlinear Media, Jeffrey Huang

Dissertations and Theses

Deformation of a Gaussian beam is observed when it propagates through a plasma. Self-focusing of the beam may be observed when the intensity of the laser increases the index of refraction of plasma gas.

Due to the difficulties in solving the nonlinear partial differential equation in Maxwell's wave equation, a numerical technique has been developed in favor of the traditional analytical method. Result of numerical solution shows consistency with the analytical method. This further suggests the validity of the numerical technique employed.

A three dimensional graphics package was used to depict the numerical data obtained from the calculation. Plots from …

Parallel Approximate String Matching Applied To Occluded Object Recognition, David Smith

Dissertations and Theses

This thesis develops an algorithm for approximate string matching and applies it to the problem of partially occluded object recognition. The algorithm measures the similarity of differing strings by scanning for matching substrings between strings. The length and number of matching substrings determines the amount of similarity. A classification algorithm is developed using the approximate string matching algorithm for the identification and classification of objects. A previously developed method of shape description is used for object representation.

Hyperbolic Soil Parameters For Granular Soils Derived From Pressuremeter Tests For Finite Element Programs, Dieter Neumann

Dissertations and Theses

In the discipline of geotechnical Engineering the majority of finite element program users is familiar with the hyperbolic soil model. The input parameters are commonly obtained from a series of triaxial tests. For cohesionless soil ls however, today's sampling techniques fail to provide undisturbed soil specimen. Furthermore, routine triaxial tests can not be carried out on soils with grains exceeding 10 - 15 mm in size.

Threshold Characteristics Of Multimode Laser Oscillators, Mehdi Khoshnevissan

Dissertations and Theses

The threshold characteristics of multimode laser oscillators are considered in detail, and a new model is given for semiconductor diode lasers. Analytical expressions and numerical solutions are obtained for mode amplitudes, and over-all spectral characteristics of lasers operating above and below threshold. The theoretical results are i n agreement with experimental data. The band-ta-band absorption is included in the model and i t ' s effect is studied on the mixed broadening.