Engineering Commons^™

Dynamic Modeling Of A Pressurized Water Reactor Plant For Diagnostics And Control, Masoud Naghedolfeizi

Masters Theses

A nonlinear model, based on lumped parameter approach, has been developed for computer simulation of a typical Westinghouse Pressurized Water Reactor (PWR) system. The model predicts dynamic behavior of system variables under steady-state and transient conditions. Nonlinear simulation has been applied to study the control systems of the PWR plant. This includes the design of proper actuator and control systems for reactor, steam generator, pressurizer, and turbine models. This model has also been used to identify the responses of plant variables to anomalies in the PWR subsystems at 85% power.

Linear models of the PWR primary loop components have been …

Effect Of Refining On The Brightness Of Softwood Ctmp And Tmp Pulps, Ashok Kumar Mishra

Masters Theses

The main objective of this study was to investigate the effect of refining on the brightness of softwood chemithermomechanical (CTMP) and thermomechanical (TMP) pulps. Seven different pulps were refined using a laboratory Valley beater. Brightness, opacity, tensile index, TEA, and fines content of these pulps were determined at four different freeness levels. Scattering (s) and absorption (k) coefficients of these pulps were calculated. One-way analyses of variance (ANOVA) were applied to determine the significance of change in brightness.

Changes in s-values were significantly affected by fiber morphology of different wood species. Refining increased the k-values of the pulps. When the …

Digital Signal Processing Schemes For Fiber Optic Rotation Rate Sensor Scale Factor Linearization, David T. Dembinski

Masters Theses

This study examined and evaluated several scale factor linearization techniques for a fiber optic rotation rate sensor (FORS). The process of scale factor linearization retrieves rotation rate from an FORS signal. Open and closed loop digital signal processing schemes are evaluated on dynamic range, accuracy, and cost.

The results of these experiments show that open loop schemes require few components but have an inherently low dynamic range of operation. Extending the dynamic range of an open loop system is expensive in additional components. Closed loop systems require more initial components, but have a considerably superior dynamic range. It was concluded …

An Ergonomic Study Of Meat Processing Operations, Edgar Delgado

Masters Theses

In this study, physical stresses imposed on the different parts of the musculoskeletal system were assessed using a subjective ratings of perceived discomfort (RPD) scale in the meat industry. The effects of a microbreak system on the perceived discomfort of employees were studied. In addition, a comparison of human physical capacities (i.e., anthropometric, strength, and endurance measures) for Caucasian-American and Hispanic-Mexican employees in the meat industry was performed. These measures were also compared against those of employees engaged in manual material handling tasks. Twenty-eight employees participated in the study.

Based on this study, it can be concluded that: (a) RPD …

A High Performance Detector Electronics System For Positron Tomography, John Clifton Moyers, Jr.

Masters Theses

Positron Emission Tomography (PET) has been a very useful laboratory tool for the noninvasive study of dynamic physiological processes within the human body. Its clinical worth in cardiology, neurology, and oncology has been verified for well over a decade. Only with the most recent introduction of high performance analog and VLSI digital components yielding higher scanner resolutions at reduced costs, has clinical PET truly become a reality. The High Performance Detector Electronics System presented here represents indubitably the most advanced processing system available in the clinical PET market.

Mocad: A Graphic Predetermined Time Standards Software For The Ibm P.C., Raad A. Dawood

Masters Theses

MODCAD is a software program designed to give MODAPTS (MODular Arrangement of Predetermined Time Standards) the capability to generate workplace layouts that can be used in conjunction with the time study analysis. Software packages have been developed for MODAPTS such as MODAPTS Plus and Task Master that allow the user to input the predetermined codes of MODAPTS.

AutoCAD (a computer aided design software) is used to combine MODAPTS codes and workplace layout drawings in a single environment by customizing the standard AutoCAD menus and icons to include the MODAPTS codes and routines. AutoLisp (AutoCAD resident language) is used to write …

A Systematic Evaluation Technique For Assisting In The Identification And Prevention Of Wrist Stress In The Work Place, Karen Kleinfeld

Masters Theses

Carpal Tunnel Syndrome is a cumulative trauma disorder involving compression of the median nerve within the wrist. This disorder has become an industrial epidemic, striking workers whose daily activities involve repetitive motion, wrist deviation, awkward finger postures, and excessive forces to the hand. In an effort to identify and control existing trauma, as well as prevent the onset of further cases of CTS, a systematic evaluation technique has been developed to assist in the ergonomic analysis of the work place. This assessment technique identifies and quantifies occupational risk factors of a task that may predispose workers to CTS. With this …

Development Of The High Vacuum Steady-State Orbitron Maser, Mark S. Rader

Masters Theses

The Orbitron MASER is a device which can be used to generate R.F. radiation. This device has been operated for many years as a gas filled pulsed device. This thesis describes a brief history, design and operation of several steady-state, hot cathode Orbitron MASER. It also touches on a pulsed Orbitron MASER and the effects the hot cathode has on the radial electric field profile. A detailed derivation of emission frequency, gain and saturation is given in Appendix.

Quiescent And Oriented Crystallization Behavior Of Linear Low Density Polyethylenes, Lawrence S. Hood

Masters Theses

A series of isothermal and non-isothermal crystallization experiments were performed on nine linear low density polyethylenes and one high density polyethylene. In addition, melt spinning experiments were performed on three linear low density polyethylenes in order to gain a better understanding of their spinline behavior and the effect of stress on their crystallization behavior.

Isothermal experiments showed that crystallization rates were dependent on branching of the polymer molecules. Resins with extensive branching had crystallization rates which were much lower than linear polyethylene. This behavior was also observed in non-isothermal crystallization experiments.

Half time analysis was performed on the isothermal data …

Microstructural Characterization Of Rapidly Solidified And Extruded Ti-Al-Nb Alloys, Danny Joe Edwards

Masters Theses

"Two titanium alloys have been characterized using transmission and scanning electron microscopy, X-ray diffraction, and optical metallography techniques. Both of these alloys were rapidly solidified by melt spinning, the resulting ribbons pulverized, and the powders then extruded into cylindrical billets. The alloys are based on the compositions Ti-21.3Al- 9 Nb-0.6-Mo-2.6V and Ti-13.2Al-2.6Nb-0.5Mo-0.9V-0.5Zr-3.1B in atomic percent. The first alloy was examined in both the as-extruded condition and in the annealed condition (looo0c for 12 hours). The second alloy was examined in the as-extruded condition only.

For the first alloy, the as-extruded microstructure consisted of a B2 matrix with alpha-2 particles at …

Fluid Dynamics Of An Atomizer Nozzle, Bhaskar Sengupta

Masters Theses

"A pilot plant gas atomizer was designed and assembled at the Center of Pyrometallurgy, U.M.R., to produce metal powders. The pilot plant utilizes a confined, annular, supersonic nozzle to yield spherical metal powders (aluminum and zinc alloys have been atomized) of average size of 15μm in diameter.

A cold model of the atomizing nozzle was constructed to simulate the pilot plant. First, the high-speed gas flow was studied and later, modelling of the atomizing process was carried out by using water as the atomized liquid. This work has investigated the complex gas flow in the converging-diverging nozzle and around the …