Engineering Commons^™

Characterization Of Pulse Duplicator Model For Testing Of Heart Valves, Pankesh Nilkamal Kadam

Theses

The design and development of a pulse duplicator system for testing of prosthetic valves is described. The performance characteristics were evaluated by computing the input impedance of the system from the measured pressure and flow signals for different simulation configurations. The study has been further extended to determine the feasibility of evaluating the cardiovascular status of a patient after major open heart procedure or in state of shock.

Built on hydrodynamic principles, the model allows for a wide range of heart rates, flow rates and mean pressures to be simulated. The artificial circulatory system used as a load to the …

Studies Directed Toward Beta-Cyclodextrin And Capped Beta-Cyclodextrin Mimics Of Alpha-Chymotrypsin, Preston Marlon Canzius

Theses

Molecular mechanics calculations were used to investigate beta-cyclodextrin and capped beta-cyclodextrin as models for the active site of alpha-chymotrypsin. The Amber molecular mechanics force field was used to investigate the effect that addition of the caps has on the conformation of the beta-cyclodextrin macrocycle.

The RMS module of Amber was used to calculate differences in position between the atoms of the minimized mimics and those of the X-ray crystal structure. The deviation in position of the atoms of the minimized capped beta-cyclodextrin macrocycle was found to be larger than that of the minimized beta-cyclodextrin, indicating that the caps do affect …

The Degradation Of Trace Pollutants In Wastewater, Christine M. Cheng

Theses

The effect of different treatments on the degradation of chlorinated organic pollutants in wastewater has been studied. The model compound investigated was para-chlorophenol. The different treatments used were ozone, UV irradiation, ultrasound, air flow and pure oxygen.

It is concluded that ozone has the greatest effect, ozone-UV irradiation follows closely behind, and UV irradiation has much less of an effect in degrading the p-chlorophenol.

P-chlorophenol was found to have an immeasureably slow degradation rate when treated with air even at an elevated temperature of 55°C.

The oxygen, at room temperature, showed a degradation of p-chlorophenol which, although small, was much …

Particle Size Distribution In Isothermal Batch Emulsion Polymerization, Bhavin R. Patel

Theses

A detailed modified mathematical model for particle size distribution in isothermal batch emulsion polymerization of Styrene and Vinyl acetate is proposed on the basis of the population balance approach in presence of several kinetic and mass transfer processes. This study is limited to Smith-Ewart's case II, which assumes instantaneous free radical termination within the polymer particles. Radical desor¬ption mechanism from polymer particles is included in the model and the desorption rate is formulated from the diffu¬sion theory which suggests that the rate co-efficient should be inversely proportional to the surface area of polymer particles.

Experimental runs are made using laser …

Process Hazard Review For Drug Development, Rudolph R. Schwarz

Theses

The development of drugs has become increasingly complex, requiring the use of a wide variety of pharmaceutical actives and isolated intermediates, a majority of which are not always completely characterized with respect to their hazard potential. This can present a source of potential exposure to those who handle these substances during initial drug development, manufacturing of the drug active and ultimately the finished pharamaceutical product. It is, therefore, essential that safety and health information be documented and communicated during the entire drug development process.

The need for application of process hazard review techniques to the development of new drug materials …

Stress Analysis Of A Stepped Shaft With A Keyway, Irfan Hussain Sabir

Theses

A stress concentration case which is encountered in practice more than any other is the shoulder fillet. Shafts, axles, spindles, rotors etc., usually involve, in each case, a number of diameters connected by shoulders with fillet radii and very often it is necessary for a keyway to be near a shoulder. The objective in this study is to analyse the stresses in a shouldered shaft with a keyway subjected to an axial tensile load and to study the dependence of the keyway-end stresses on the distance between the shoulder fillet and the keyway end. This is done by performing a …

Construction Labor And Productivity : Productivity Improvements, Stavros C. Nicolaou

Theses

Construction productivity has been on the decline in the last decade. Although an important factor in the nation's economy, productivity of construction labor has been given little attention over the years. A review of the literature dealing with construction was performed that revealed the importance of the declining productivity as well as the confusion among construction managers and labor leaders as to what productivity is all about and how it can be improved. It has been found also, that construction labor motivation, which is the most important factor in improving productivity, is almost nonexist. Very few construction companies employ any …

A Mathematical Model Of Photopolymerization In A Batch Reactor, Jyh-Yao Li

Theses

A mathematical model of a photo initiated additionpolymerization in a batch reactor was developed.

The model considered initiation, propagation and, termination to simulate the addition polymerization process, The model has the advantage that the concentration of any particular n-mer may be calculated without calculating all of its precursors. Other methods do not have this property. An analytical solution to the model for the photopolymerization of styrene was solved. The calculations were run on a VAX 8800 computer and the results were then compared with the experimental results. The calculated results fitted the experimental results to some extent. Effects from the …

Non-Linear Finite Element Of Analysis Of Reinforced Concrete Members, Chellathurai Jeyamohan

Theses

A finite element analysis of reinforced concrete members is used to study the initiation and propagation of cracks and the behavior at the interface of concrete and steel. The increase of concrete strength due to the biaxial compression and the shear capacity of the cracked elements are also considered in the analysis.

The results of the present analysis are compared with some available experimental data in beam tests. It has been found that the present analysis is capable of calculating the stress ( or moment ) and strain ( or deformation ) from zero load upto the ultimate load.

Analysis Of Nitrated Polycyclic Hydrocarbons, Pah-Quinones And Related Compounds In Ambient Air, Yalan Wang

Theses

Studies were conducted to characterized airborne particulate extractable organic matter (EOM) with respect to chemical composition and biological activity. It has been well established that the nitrated polycyclic hydrocarbons (nitroPAH) are environmental contaminants. To identify nitro-PAH in ambient air sample, a technique was developed involving introduction of a reducer column into an reversephase high performance liquid chromatography (HPLC) system. Strong fluorescence signals were achieved from nitro-PAH and detected together with u.v. signals for the qualitative and quantitative analysis of nitro-PAH. 2-Nitrotriptycene was synthesized according to published procedures and used as an internal standard. By use of the above technique, 9nitroanthracene, …

Feasibility Of Using Canine Olfaction As A Means Of Detecting Hazardous Substances, Stuart David Messur

Theses

Two specific applications for using canine olfaction as a means of detecting hazardous substances have been recognized: detection of residual contamination on hazardous waste cleanup equipment (DECON), and detection of leaking underground gasoline tanks (LUST).

With the DECON project, the dog's ability to detect low emissions of some common hazardous compounds was tested. As a safe and effective training tool for presenting hazardous compounds to the dog, permeation tubes filled with m-xylene or 1,1,1-trichloroethane were constructed and calibrated. Hidden tubes emitting as low as 0.5 µg/min were consistently detected by the dogs. During olfactory field tests, "hot spots" of m-xylene …

An Investigation Of Electrical And Optical Properties Of Sputtered Amorphous Silicon Nitride And Germanium Thin Films, Rajendra S. Khandelwal

Theses

Low temperature preparation of thin amorphous Silicon Nitride and Germanium Films by direct RF sputter deposition was investigated. Influence of various sputtering parameters on film properties was studied. Infrared transmission spectrophotometry was used to evaluate optical properties of the films whereas electrical characteristics of the films were determined from current-voltage measurements of MIS structures. For Silicon Nitride films it was observed that the stoichiometry, as indicated by the IR transmission, dielectric constant and current density versus square root of electric field measurements, was a strong function of the sputtering gas composition and particularly the Ar/N ratio in the sputtering gas. …

Properties Of Sputtered A-Ge And A-Ge : H Thin Films, Hanjin Cho

Theses

The effect of the amorphous and glassy structure of amorphous germanium films on their electrical characteristics was investigated experimentally. The films were deposited onto silicon substrates using a modified MRC 8800 triode sputtering system. The Poole-Frenkel and Schottky mechanisms are discussed in detail and the shortcomings of the accepted picture of the former in amorphous materials are dealt with. It was concluded on the basis available evidence that the current flow in amorphous germanium favors the Poole-Frenkel mechanism at high fields.

Amorphous hydrogenated germanium films which were deposited by bias sputtering were characterized by measuring the infrared absorption. The films …

Failure Surface Of A Square And Rectangular Reinforced Concrete Members [Sic] Under Combined Biaxial Bending And Tension, Ravindra M. Khanapure

Theses

This thesis describes the development and use of three dimensional strength interaction diagrams of reinforced concrete sections for different loading conditions. It also gives a comprehensive overview of modes of failure surfaces and provides design aids for members subjected to biaxial bending and axial tension. This is the phenomena which is rather overlooked analytically and graphical predictions are made. The computer program provides a special tool for the analysis and fast interation of combination of loadings and moments.

A Mathematical Model For The Isometric Contraction Of Smooth Muscle On The Basis Of The Phosphorylated Myosin Regulation Process, Joseph J. Kocinsky

Theses

A mathematical model was proposed for the isometric contraction of smooth muscle (i.e., vascular, urterine, & gastrointestinal) that accounts for the experimental observations on tension transients and pCa²⁺-tension curves. The model is based on the elementary reaction kinetics involved in the process; it uses the Ca²⁺-dependent myosin phosphorylation regulatory mechanism in its interpretation. The model is composed of four parts : (a) the activation of myosin light chain kinase; (b) the phosphorylation of myosin light chains; (c) the actin-myosin Mg²⁺ATPase cross-bridge reaction cycle; and (d) the development of isometric tension. The interaction of the …

Reliability Evaluation Of Liquid Crystal Displays Under Accelerated Life Conditions, Rajkumar Krishnamoorthy

Theses

This Thesis shows method of comparing the reliability of Liquid Crystal Display Devices by means of accelerated life testing at elevated temperature and relative humidity for two different vendors.

The tests were carried out at three different combinations of temperature and humidity.

1. 77°±1° C and no added humidity.

2. 85°±1° C and no added humidity

3. 98°±1° C and 98+2% relative humidity.

Leakage current measurements were carried out after every 1000 hours for up to 5000 hours for vendor no.l. Measurements were carried at 0, 500, 1000, 2000, 3000 and 5000 hours for vendor no.2. A DC bias of …

Image Analyzing Instrumentation System For The Activity Measurement Of Rats, Yun-Kang Li

Theses

A microcomputer based instrumentation system has been developed to measure the activity of rats in 12 metabolic chambers. The instrumentation system monitors the rats' behaviors and estimates their activity continuously in an automatic manner. The activity information of the rats are expressed by a quantitative index which describes the intensity of the activity level.

An Apple II microcomputer system is used to manage the activity measurement which consists of an image recording operation and an image analyzing operation. During the measurement, the microcomputer controls Optic RAM digital cameras to record the rats' image. The camera can take a digital picture …

A Study Of Failure Modes In Rock Resulting From Pile Penetration, Girish Mehta

Theses

The purpose of this thesis was to physically examine the failure mode of a rock mass as a result of pile penetration. In addition, the static bearing capacity of piles bearing in rock was investigated. This was accomplished in the laboratory by performing model tests using a dynamic pile driving device.

Tests were performed using 1 inch nominal diameter model pipe piles and H-piles. Piles were driven into a simulated rock mass consisting of clay-masonry bricks. Following pile driving, the rock mass was carefully dissected and observations of the failure mode were made.

A new technique was developed to preserve …

Bond Behavior Of Reinforced Concrete Under Impact Loading, Abu Rayhan Md Muniruzzaman

Theses

This thesis covers experimental investigations of bond behavior of reinforced concrete specimen under impact loading. A computer assisted data acquisition system was selected for data acquisition and control. This entire electronic system involved mainly a multichannel digital oscilloscope and an IBM-AT micro computer. All specimens were tested by a modified instrumented Charpy tester assisted by the electronic system.

15 test specimen were prepared in order to perform the experimental investigations. Each 3x3x16 inch specimen was reinforced with a single deformed bar mainly 3/4" and 1/2" diameter and three catagories of concrete mainly plain, 1%, and 2% (by volume) steel fiber …

Hardware Based Data Compression System Using Sliding Dictionary Algorithm, Hemant L. Nerurkar

Theses

Popular data compression schemes found in the literature are software based and present innumerable difficulties in hardware implementation. A data compression scheme, which can be directly implemented in hardware using systolic arrays, has been described. The scheme has a remarkable ability to 'adapt' itself to the changing statistics of the source file. Results generated after a comprehensive study and simulations of the algorithm have been presented. The scheme is inherently suitable for parallel processing. It can be incorporated in transmitting devices since it can be fabricated on a single VLSI chip. Comparison has been made with the LZW scheme. A …

Optimization Of The Design Of The Harrington Distraction Rod And Hooks, Margaret Ann Pisani

Theses

The Harrington Distraction Rod is presently attached to the spines of patients who suffer from scoliosis and vertebral fractures. The rod's purpose is to apply a distractive force to the scoliotic curve in an attempt to reduce its severity. In fractures this rod is implanted to reduce the fracture and increase the stability of the spinal column. Harrington distraction rods are also inserted in order to give mechanical support to the spinal column.

Presently the Harrington Distraction Rod, manufactured by Zimmer, is one—quarter inch in diameter and made of 316L cold—worked stainless steel. The proximal end of the rod consists …

Kinetic Study Of Degradation Of Refractory Organic Chemicals : 2, 4-Dichlorophenol, 2, 4-D And Pyridine; Using Ozone/Hydrogen Peroxide/Uv Radiation, Milind K. Pradhan

Theses

In this study Ozone/Hydrogen Peroxide/UV radiation is used to destroy refractory organic chemicals in aqueous solutions. 2,4-dichlorophenol, 2,4-D and Pyridine are the three chemicals used. Hydrogen Peroxide in combination with UV light proved to be most effective in destroying the parent chemical completely. Ozone and UV system was the next most effective system. UV alone was the least effective.

Kinetic study of the Hydrogen Peroxide and UV system was done using a Chemkin program. The results predicted by the Chemkin program matched closely with the experimental results. More work is currently being done using the Chemkin program to study other …

Finite Element Analysis Of The Temperature Field In The Course Of Laser Heating, Moududur Rahman

Theses

This study is aimed at the developement of a computational procedure for the prediction of temperature and the concentration fields in the course of surface processing by high energy beams. The finite element technique is used for the solution of two dimensional problem of heat conduction in a solid subjected to the laser radiation. The preprocessing, solution and the postprocessing were carried out by the use of ANSYS software package. The laser energy was simulated by heat generation at the shallow subsurface or by the temperature of the impingement zone. Equal square elements were used for computations. It was found …

The Non-Contacting Surface Area Assessment Of Burn Wounds Using Computer Imaging Methods, Sarmishtha Meeta Rath

Theses

The need for a reliable and accurate method for assessing the surface area of burn wounds currently exists in the branch of medicine involved with burn care and treatment. The percentage of the body affected by burns, measured by the percent total burn surface area, is of critical importance in evaluating fluid replacement amounts and nutritional support during the first 24 hours of postburn therapy. A simple technique has been developed which facilitates the measurement of burned areas non-invasively. Directly measuring burn surfaces yields quantitative results which can be used in assessing the extent of burns, monitoring the healing progression …

Flexural Behavior Of Portland Cement Based Composites Subjected To High Strain Rates, Edward Roland

Theses

This investigation studied the modulus of rupture and energy of rupture of mortar, concrete, and steel fiber reinforced mortar at various rates of flexural straining. The strengths of the composites were varied by changing the water cement ratios. Single point flexural loading tests were conducted on 4" x 4" x 20" specimens using a weight dropped from a height of 30" to produce the dynamic loading. Strain rates were varied between 0.1 and 1.9 per second. The inertial effects of acceleration of the specimen were taken into account.

These tests produced data that demonstrated slightly greater ratios of dynamic to …

Sorption Characteristics And Their Effects On Geotechnical Properties Of Illite, Gnanmoorthy Selvakumar

Theses

An experimental investigation of the sorption characteristics of phenol, chlorophenol and chlorobenzene on to illite and of the effect of sorption on the geotechnical properties of illite was performed. Various adsorption isotherms have been considered for the equilibrium adsorption study data. It was found that the Freundlich adsorption isotherm closely fits the experimental results. In addition, the results of desorption study indicated that the sorption process for these systems is not completely reversible.

The index properties of illite were found to be influenced by the sorption of contaminants, i.e., the Atterberg limits of illite increased in accordance with increases in …

Investigation Of The Size Of Gallium Clusters Formed Using A Modified Ion Cluster Beam Source With A Crucible Temperature Of 1250 Degrees C, Sujit M. Shah

Theses

Energy analysis of the ionized gallium clusters was done by retarding field method. The objective of this research was to investigate the possibility of gallium cluster formation during nozzle jet expansion and to estimate the probability of ionization of clusters. The measurements at a crucible temperature of 1250°C corresponding to gallium vapor pressure of 0.23 torr (inside the crucible) showed that no large cluster sizes could be obtained. The relationship between mass deposition rate (atoms/cm2-sec) and cluster size (atoms/cluster) showed that there were two distinct peaks. One with a cluster size of 1 atom/cluster and the other with about 13 …

Graphical Interpretation Of U.S. Tidal Data, Vaheh Shahbazian

Theses

Numerous Shore line operations relating to industry and conservation would benefit from convenient access to continuous tidal predictions. Easy Graphical access to continuous long term predictions of tidal heights at a location of interest will simplify operations that are sensetive to tidal predictions. A specific example, is the implementation of a protective measurements against flooding and destruction of shoreline facilities particularly at times of high tides.

This thesis consists of three things. First, rendering NOAA's data in a form accessable to a PC user. Second, it provides a Basic program for prediction of tides. Third , PC user programming Resourses …

Reliability Studies On Microcircuit, Salim Shehadeh

Theses

The primary objective of this thesis is to determine and analyze the failure mechanisms of Low Power Schottky microcircuit device (2-Input NAND Gate). Pinpoint the causes, and suggest the precautionary measures that prevent the occurrence of these failures. To achieve this goal, the study went in two directions, theoretical and experimental. The theoretical part is a comprehensive review of the work done on Low Power Schottky 2-Input NAND Gates since 1960 up to date.

The experimental part of the study is a life test ( 1000 hours ) of 2-Input NAND Gates under humidity and high temperature.

For each unit, …

Life Testing Of Solid Dielectric Materials, Muhammad Irfan Soomro

Theses

The main objective of this thesis was to find correlation between the electrical noise generated within the body of the solid dielectric material with the failure (puncture), under simultaneously applied thermal and electrical stresses.

The term 'Corona' is commonly used to describe any partial discharges occurring in voids (defects) in the material. Precisely corona is a flow of electrons and ions which occur in a void in air or other gasses. This event emits acoustic, optical and radio frequency energy, and can be detected by measuring any of these radiations. In the present thesis, Radio Interference Voltage (RIV) technique was …