Digital Commons Network^™

Replacement Of Surface Ducted Rays Near Caustics With Guassian Beams, Carlos Javier Ruiz

Theses

Conventional approach to a solution of a wave propagation problem in an inhomogeneous medium is to utilize either rays or modes to represent the wave field. Asymptotic ray theory (ART) starts to fail in the vicinity of caustics due to rays experiencing many reflections. Even uniform representations do not properly correct this deficiency of rays when caustics start to pile up in the far range. One possible alternative is to replace these rays with modal bundles and remainders [1]. A promising technique using Gaussian Beams has been used to represent the total field due to a point or a line …

Effects Of Physical Exertion And Caffeine Ingestion On Mental Performance, Alireza Shafiei

Theses

Stresses in man-machine systems can be broadly classified as (1) physical and (2) mental. Both types of stresses generate some kind of response in the human body. These responses could be physiological (quantitative) or behavioral (qualitative). While the physical stresses mostly create physiological changes, mental stresses may cause physiological and/or behavioral changes. The purpose of this study is to investigate such influences, and try to determine if stimulants such as coffee have any effect on people's ability to perform tasks involving a combination of physical and mental elements.

An attempt has been made to describe an interrelationship between physical exertion …

Design And Optimization Of Nmos Sense Amplifiers For Vlsi Drams, Nimish K. Shah

Theses

The aim of this thesis is to study and optimize the performance of NMOS sense amplifiers used in modern VLSI DRAMs.

Initially dynamic memory cells and popular sense amplifier circuits are surveyed.

A standard five transistor sense amplifier is later chosen for detailed analysis. Layout of the circuit is drawn to get the physical parameters. Using SPICE simulator, various effects of circuit parameters are studied. From these results optimal values of these parameters are arrived at.

Also an effort is made to derive theoretically equations for the latching time of a post amplifier which is the most important part in …

The Effects Of Platelet Activating Factor (Paf) On The Arteriolar Average Blood Velocity And Volumetric Flowrate In The Microcirculation Of The Hamster Cheek Pouch, Patricia Ann Shatynski

Theses

The effects of platelet activating factor (PAF) in vessel diameter, average red blood cell (RBC) velocity and volumetric flowrate were studied in twenty-four arterioles located in the cheek pouches of nine male syrian golden hamsters. The observed vessels were between 8-32um in diameter. These vesgs were subdivided further into two groups: 8-17um and the 21-32um group. Fluorescein isothiocyanate (FITC) labeled cells were injected into the hamster to act as velocity tracers. Immediately prior to and for a total of 60 minutes after the topical application of 10^-7M and 10^-9M PAF, selected arterioles were video taped periodically …

The Stress Distribution Of The Frp Pressure Vessel By Using Ansys Program, Lung-John Tsai

Theses

The objective of this paper is to take advantage of a general purpose finite element computer program, called ANSYS, to analyze the surface stress distribution of a fiber reinforced plastic (FRP) laminated composite pressure vessel. The vessel is subjected to internal pressure, which is assumed to be constant over the interior surfaces.

In this paper, the material is assumed to be orthotropic, and the stress-strain relationship linear.

A FRP pressure vessel subjected to an Internal pressure, 6.895 MPa (1000 psi), is taken as an example. The results show that this approach compares well with a theoretical solution.

An Analysis Of Carrier Facilitated Transport In Liquid Surfactant Membranes, Pei-Jen Tsai

Theses

Mathematical models describing the mass transfer through facilitated liquid membranes are proposed and solved analytically. A self-adjoint operator method is applied to solve the coupled differential equations with discontinuity in the boundary conditions. It is assumed that equilibrium of the solute at the interfaces is maintained during the separation process. The effects of film resistance are studied/ and a first order kinetic model is used to simulate the reaction which takes place at the membrane-internal phase interface.

Experimental results indicate that the model with external film resistance consideration is in good agreement with the experimental data. This shows that most …

Ray And Beam Representation Of The Glancing Phenomena, Michael Sotiriou Vogas

Theses

Asymptotic ray theory (ART) is a widely used method dealing with problems of wave propagation in an inhomogeneous medium. The main deficiency of ART is in transition regions where rays near caustics, glancing and critical incidence fail to represent the actual wave field. Ray bundles in such transition regions have been successfully replaced with modal bundles and remainders El] in well defined profiles. However , in practical problems it is difficult to implement modal representations and almost impossible to express remainders. Recently emerging Gaussian beam method (GBM) has shown promising results in representing the total field produced by a source …

Multi-Channel Arrhythmia Analysis In The Clinical Exercise Electrocardiogram, Shi-Xiong Yang

Theses

This thesis studied methods of using 2 channel ECG signals for noise elimination and arrhythmia detection. Clinical data were recorded from patients stress tests and were stored on diskettes for off-line processing. Spatial velocity vector and noise estimation methods in addition to analog and digital filters were combined to remove the noise produced from different sources. Feature extraction and matched filter methods were employed for classification of normal and abnormal QRS complexs, while rhythm computing was used in addition for PVCs and other arrhythmia discrimination. This algorithm was tested on clinical stress test recordings and a computer simulated arrhythmia recording …

Plate Stress Analysis By The Finite Element Method, Wen-Jung Chuang

Theses

The finite element formulation of plate elasticity is presented and is employed in the development of the formulation of element stiffness equations. The programming structures are also summarized.

The finite element program PLATE cited from Prof. J. N. Reddy's " An Introduction to the Finite Element Method " has been used to solve the plate bending problems with quadrilateral elements. The problems solved are:

(1) deflections and stresses in a circular plate with all edges simply supported under uniform load.

(2) deflections and stresses in a circular plate with all edges clamped under uniform load.

each case including four different …

An Analysis Of Different Desalination Processes, Vahe Garabed Hovsepian

Theses

The object of this thesis is to study the various modes of desalination and analyze the energy and economic requirements. The desalination methods discussed are, single stage desalination, Long tube vertical Evaporator, Multistage Flash distillation, Solar Energy method, Freezing method, Reverse osmosis & Electrodialysis.

It was found that for vapor reheat process at 350°F input 639 ft-lbs/lb product required 2.01 kw-hr/100gal. product and the total cost 51.6c/1000gal.

Not one process is best for everyone. In countries close to the equator, the solar energy method is the best. Most other countries depend on flash distillation process, etc. So we can't draw …

Implementation Of Finite Element Method On A Microcomputer, Chi-Yuang Huang

Theses

A finite-element program FEM2D has been implemented on a PHILIPS microcomputer. The program has a generation preprocessor and thus makes finite-element analysis on a microcomputer considerably easier than before, since it allows models to be created and edited much faster than by manual method. The interactive program FEM2D prompts the user to input data directly from the screen. It is convenient for the user, both in teaching and learning.

The FEM2D is a two-dimensional finite-element program capable of solving two-dimensional problems, such as plane elasticity, heat transfer and imcompressible fluid flow problems. It is developed with a formulation of a …

College Relations : A Total Recruiting Strategy, Donald Roderick Hunt

Theses

Problem Statement

The MMH Corporation has a very experienced but older engineering population. It is management's desire to replace the engineering population as its members retire by two methods:

1. The recruitment of experienced engineers with key skills for various critical positions.

2. The development of an aggressive and effective College Relations Program targeted at key universities to attract a steady stream of new talent into the engineering populations.

Research Objectives

A. To determine what areas of a volatile marketplace MMH intends to compete in.

B. To determine what attracts the best new college graduates to a certain company as …

In Vitro Comparative Hydrodynamic Study Of Heart Valve Bioprostheses Under Accelerated Fatigue Conditions And Under Physiological Conditions, Mario Cincinat Iosif

Theses

The present study involves the use of an accelerated fatigue testing system*, and a pulse duplicator (heart simulator)*, to evaluate the hydrodynamic characteristics of cardiac bioprostheses.

The hydrodynamic performance of these prosthetic valves is compared when tested using each machine, in order to assess the determining conditions that exist for each case, and try to correlate them.

Pressure drop and pulsatile flow across valves are measured, using a real-time on-line data acquisition system, which includes, in addition to the fatigue tester and the pulse duplicator, a DC amplifier, an analog-to-digital converter and a digital microcomputer. Special acquisition software has been …

Microcomputer Local Area Network Interface, David W. Juan

Theses

A Microcomputer Local Area Network Interface system for use in the study of Local Area Network has been built and tested. The special feature of the system is data transmission/receiving and error detection/recovery. The system adapted the International Standards Organization (ISO) Open System Interconnection COSI) model. It used the star topology and implemented the physical layer, data link layer and network layer. The results of the system indicated the data communications and resources—sharing between microcomputers.

Study Of The Effects Of Pumping Pressure On The Properties Of Fresh Concrete, Dinesh Vithal Kenkre

Theses

This thesis has a two-fold objective. One, to develop a suitable testing apparatus in the labaratory to simulate the effect of field pumping of concrete and two, to conduct some preliminary tests to investigate the feasibility of the testing apparatus.

Pumping of concrete has been practiced in the U.S.A. since 1930. The behaviour of concrete in a pipeline has not been studied in much detail while development in the pumping technology raced ahead of the research in this field. Previous studies done in this field have clearly indicated the need for a laboratory simulation of pumping process in order that …

Computational Method For Robot Manipulator Dynamics Based On The Gibbs-Appell Equations, Kwang Bok Kim

Theses

Industrial robots are open-loop multi-degree of freedom mechanisms whose dynamic characteristics are described by nonlinear differential equations. The computations of forces and torques required at each joint of robot manipulator are crucial step for real time control of robot manipulators.

Vukobratovic developed a new computational method for rigid body articulated open-loop mechanisms based on the Gibbs -Appell equations to generate differential equations of motion for spatial open - chain mechanisms. To solve these equations, he introduced the recursive kinematic transformation matrices that represent the motion of each linkage with respect to the base linkage.

Computer programs are developed in this …

Laminar Flow In A Porous Pipe With One Plugged End, Pyne-Hwa Ku

Theses

A steady laminar flow through a co-cylinder porous pipe with one plugged end was investigated theoretically to obtain velocity, pressure and shear stress distributions.

An integral momentum equation and the Darcy's law for flow through the porous wall were solved numerically by the Runge-kutta method.

As the fluid is injected from the outer wall into the porous tube, the fluid in the inner tube is accelerated from rest at the plugged end to a fully-developed velocity profile at the exit of the porous tube. It was found that the coefficient of the wall shear stress and the dimensionless pressure drop …

Preparation And Properties Of Monomers Derived From Hydroxyhexyl Methacrylate For Dental Adfesive, Ren-Dar Ku

Theses

Although methacrylic acid is the simplest unsaturated carboxylic acid and its hydroxyl ester polymerize readily, yielding useful resins, no adequate study of the preparation and application of the higher hydroxyl alkyl methacrylates has been published. The commercially important hydroxyethyl and hydroxypropyl methacrylates are manufactured from the appropriate alcohol in the presence of sulfuric acid, a method which appears to be less suitable for production of higher hydroxyl alkyl methacrylates. The purpose of the present work was to prepare the hydroxyhexyl methacrylate (HHMA) by a generally applicable method and determine its common physical properties. In addition, the urethane methacrylates were synthesized …

Computer Aided Mathematical Modeling Of A Once Through Claus Type Sulfur Recovery Process, Yuriy Osyp Kutny

Theses

The computer aided mathematical modeling of the once through Claus process for hydrogen sulfide conversion to sulfur is presented herein. This vapor phase oxidation reaction is carried out using one thermal reactor and up to three bauxite catalytic reactors with sulfur condensers in between. The method of catalytic reactor feed reheat and its ramifications upon reactor performance and total model convergence is of major importance.

The reactor feed preheat can be carried out in either of the following ways: (1) indirect heat exchange using some external heat source; (2) indirect heat exchange using other hot process streams as heat source; …

Design And Evaluation Of Performance For The Multi-Microprocessor System, Sang-Soo Lee

Theses

A tightly coupled multiple-microprocessor with two MPU's that can be run at different clock speeds has been built and tested. The method of interconnection for this multiprocessor is a timeshared common bus with shared memories having a tightly coupled architecture. The signal timipg of the multiprocessor system for different speeds has been investigated using a logic analyzer for simulation modeling. The desired timing results have been obtained. According to the timing results, the simulation model for the General Purpose Simulation System has been correctly designed and performance of the multiprocessor system for the various clock speeds has been evaluated by …

An 8052 Ah - Basic, Based Development System, Suresh Vishwanath Leley

Theses

This project exploits the latest in microcontrollers-an entire environment for developing and prototyping a microcontroller application. With one key chip, a little glue, and a Dumb terminal a powerful system is achieved at a vanishingly small cost. This "one chip" system is adequate for realizing a wide range of applications calling for a small computer or an embedded processor.

Besides economy of system cost, the turn around time from concept to functioning application can be extremely short, even when the development engineer is not particularly well acquainted with traditional assembly language and microprocessor development practices. This economy is achieved by …

Stress Analysis Of A Pressure Vessel By The Finite Element Method, Hsin-Te Liao

Theses

The objective of this paper is to take a finite element program, called ANSYS, to analyze the surface stress distribution of a thin-wall pressure vessel with a spherical head.

The computer program ANSYS, which primarily applies the principle of virtual work in solid continuum, has been used to solve shell problems with quadrilateral element. Problems solved are: <1> hoop stress <2> meridional stress (<)3) maximum shear stress.

In this paper, the theoretical finite element formulation of axisymmetric elasticity of the ANSYS program is presented.

Finally, some numerical examples of shells with spherical heads of various radius are given. The solution obtained from ANSYS is very …

Linearization Accuracy In Probabilistic Load Flow, Guan-Zhong Liang

Theses

This paper presents a linear load flow method which can be used for probabilistic load flow analysis. The method is based on least-square estimation. To estimate its accuracy in linear load flow calculations, the method and a previously developed linear load flow method are applied to a typical power system and the results evaluated. Comparable accuracy is noted.

Air Pollutant Emissions From Non-Vented Radiant Kerosene Heater, Anil Kumar Mishra

Theses

Gaseous emissions from non-vented kerosene heaters can generate and create significant indoor air concentrations of various gaseous pollutants. Indoor air concentrations resulting from operating a portable non-vented radiant type kerosene heater in three rooms of size 38.7, 58.1 and 137 M³ were studied. Studies in the environmental chamber having a size of 38.7 M³ under two sets of ventilation conditions showed elevated levels of CO₂, total hydrocarbons and CO. An emission rate model was used to estimate the strength of pollutant source, for total hydrocarbons, CO₂ and CO with data reported in terms of mass …

The Cocoa Rehabilitation Project In Ghana, Kwane Boakye Dankwah

Theses

Several studies have been done in an attempt to find out the cost involved in establishing an acre of cocoa farm and most of these used the questionnare method to gather the information. However, most data gathered this way did not include detail establishment cost information on inputs as the farmers relied on recollection of cost they incurred.

The study done by C. Okali at Dominasi in the Brong Ahafo Region did not follow this pattern. Data collection for this study was started in May 1971 and ended in September 1972 and there were 45 farms involved. This sample was …

Reliability Study Of Liquid Crystal Display, Kalpesh Mahendra Desai

Theses

The purpose of this thesis is to study the reliability of liquid crystal display under different temperature conditions. To accomplish this, accelerated life testing was done on the soft glass and the hard glass liquid crystal display units at 77 C and 85 C temperature without any added humidity or voltage.

As the current is a usefu1 indicator for probable wear of liquid crystal display, leakage current was measured at 0 hour, 1000 hours, 2000 hours and 3000 hours when the units have stabilized at room temperature.

The date shows higher spread for the hard glass units. This may indicate …

Systems Building Theory Application Within The Residential Housing Construction Market, Gary Alexander Newhard

Theses

The primary purpose of this report is to introduce the economical value in utilizing certain "systems building" applications. In this report I focus on integrated system methodologies that encourage residential building economy and submit such systems as a viable alternative to traditional labor intensive housing construction. The consumer market that could be particularly enhanced by these systems ranges from low income to middle income and the by-product would be classified as "affordable" housing.

This report focuses on the New Jersey real estate market and presents certain prefabricated housing systems as an economical means of meeting the large demand for residential …

Modal Analysis Of A Cantilever Plate, Ohseop Song

Theses

This thesis discusses the vibration of a thin, flat cantilever aluminum plate. Results are based on both an analytical finite element method using the ANSYS program and an experimental analysis using a digital Fast Fourier Transform (FFT) analyzer. The FFT analyzer permits extraction of modal parameters (natural frequency, damping, mode shape) for the plate.

Biodegradation Of Multiple Substrates In A Batch Reactor, Nilesh Naik

Theses

The biological degradation of multiple substrates was studied at room temperature in aerated 5-liter batch reactors using mixed liquor from the Passaic Valley Sewerage Commissioners wastewater treatment plant (Newark, New Jersey).

Two substrate mixtures were used (with initial concentration indicated in parenthesis): (1) phenol(100ppm) + nitrobenzene(10ppm) + 2,6-dichiorophenol(10ppm); (2) 2-chlorphenol(20ppm) + nitrobenzene(10ppm) + 2,6-dichlorphenol(10ppm). From concentration versus time data, kinetic rate constants for zero-order, first-order, and Monod models were determined. Most of the data were best fit by either the Monod or zero-order model. For all compounds tested biodegradation was the primary removal mechanism, and in many cases the rate …

Measurements Of Basic Semiconductor Properties, Abdolreza Ariantaj

Theses

Mobility, resistivity, and total impurity concentration of several purchased p-type silicon samples with known resistivities were measured by Hall effect, experiments utilizing the Van Der Pauw method. The silicon samples will serve as Hall effect standards for future measurements on other semiconductor materials, particularly gallium nitride ion cluster beam (ICB) deposited thin films. The samples which were Freshly etched with hydrofluoric acid had measurement values of 455 cm ² / V.sec, 45.9 Ω cm, and 2.6 X 10¹⁴ cm³ for mobility, resistivity, and total impurity concentration, respectively. The mobility values were within 9.9 per cent, of the published values …