Digital Commons Network^™

Biodegradation And Landfill Settlement, Shailesh Pisolkar

Theses

The most widely used method for the final disposal of solid waste is landfilling, which is also economical and simpler than most other disposal systems. Long term settlement in a landfill occurs mainly due to biodegradation of the refuse which is a very slow microbiological process. However, if the rate of biodegradation is enhanced, it may be possible to achieve early stabilization, faster settlement, consequently more capacity of the landfill to handle waste.

The objective of this research is to study the effects of enhanced biodegradation on settlement and to compare these results to other models used for predicting landfill …

Solids Suspension And Power Dissipation In Stirred Tanks Agitated By An Impeller Near The Tank Bottom, Ernesto Uehara-Nagamine

Theses

In this work, the effect of very small impeller clearances off the tank bottom, C, on complete solid off-bottom suspension, Njs, was investigated. Four types of impellers were used six-blade flat-disk turbine, six-blade flat-blade turbine, six-blade flat (45 degreees) pitched-blade turbine, and the high efficiency impeller Chemineer HE-3. The effects of the impeller diameter, D, tank diameter, T, and solids loading, X, were quantified. The presence of two impellers was analyzed using impellers of the same type and size.

Typically, Njs and the power consumption were found to decrease with the impeller clearance. However, for lower C/T values, a slight …

Fabrication Of Integrated Optic Sensor To Monitor Pollutant Concentration In Effluents, Kiran Chatty

Theses

An attempt has been made to fabricate an integrated optic sensor to monitor pollutant concentration in effluents. Optic fiber has to be coupled to the waveguide in order to send light through the waveguide. In order to facilitate the easy coupling of the fiber to the waveguide, V-grooves were formed in the silicon substrate. In order to achieve this Silicon nitride was deposited to serve as an etch mask. An attempt was made to obtain low stress silicon nitride films.

This work also attempted to synthesize the materials required to fabricate the waveguide. LPCVD processes were developed to produce undoped …

Surface Phenomena On The Tin-Dioxide Polycrystalline Layers, Andrei A. Fluerasu

Theses

Polycrystalline tin-dioxide is widely used in the detection of reducing gases (such as H₂, CO, CH₄, C₂H₅OH,...) in air by measuring its conductivity changes. The advantage of gas sensors based on such sensing devices is low cost and high sensitivity. In contrast to their widespread applications and to their successful empirical research and development work, the present understanding of the chemical sensing mechanisms is still immature.

In this thesis, for gas sensors based on thick and porous tin-dioxide layers, a study of the response function upon variation of the partial pressure of …

Modeling Of Cardiovascular System To Simulate Ventricular Septal Defect, Adarsh Kumar Gupta

Theses

The hemodynamics of the ventricular septa] defect is studied using a mathematical modeling technique. A twelve-compartment windkessel model of cardiovascular system is used to study the hemodynamics of the ventricular septal defect. The VSD is incorporated into the model via a parallel flow from the left to right ventricles (left-to-right shunt). The resistance to flow through the shunt is used to characterize the severity of the defect. Changes in the severity of the shunt flow produces changes in the ratio of pulmonary to systemic flow in the circulation. When the pulmonary to systemic flow ratio is more than 2:1, the …

The In Vitro Evaluation Of Various Biodegradable Composites Used In Internal Fixation Devices, Hui-Chen Hsieh

Theses

In vitro degradation kinetics and mechanical properties of various composites, comprising a polycarbonate (DTE polymer) reinforced with CaP glass fiber, synthetic ceramic and non-ceramic hydroxyapatite (HA-500,OsteoGen HA) were investigated.

They were soaked in the SBF solution with a constant pH of 7.4 at 37°C for 5 days. The DTE/CaP composite degraded in an acid manner such that a large amount of NaOH was required but with a small decrease in calcium ion concentration. By contrast, the DTE/OsteoGen HA composite required comparable amounts of NaOH, but with a concomitantly large decrease in calcium ion concentration. This showed that the OsteoGen HA …

Synthesis And Characterization Of Silicon Dioxide Thin Films By Low Pressure Chemical Vapor Deposition Using Ditertiarybutylsilane And Oxygen, Sung-Jun Lee

Theses

This study is focused on the synthesis and characterization of silicon dioxide thin films deposited on silicon wafers by Low Pressure Chemical Vapor Deposition (LPCVD), using ditertiarybutylsilane (DTBS) as a precursor and oxygen as the oxidant. The dependence of film growth rate on various process parameters were studied. The growth rate was found to follow an Arrhenius curve with the variation in the temperature with an activation energy of 12.6 kcal/mol. The growth rate was found to be inversely proportional to the temperature in the range 550-750 °C. The refractive index and density were observed to be close to 1.47 …

Effect Of Lamellar Microstructure On The Permeability Of Polyethylene Films, Yufu Li

Theses

Lamellar microstructures can decrease the permeability to gases and vapors by increasing the diffusive path in plastic films, or the so-called "tortuosity" which depends on the aspect ratio, orientation, and the volume fraction of the dispersed material. In this research, different types and percentages of mica with relatively high aspect ratio are used as oxygen barrier materials in blown films. Both high and low density polyethylenes (HDPE and LDPE), as well as their blends are used as the matrix materials.

A decrease in permeability of both LDPE and HDPE films to oxygen is achieved with increasing volume fraction of the …

Relationship Between Precipitation, Surface Runoff, And Shallow Water-Table, Manoj Patel

Theses

In this study, a model was developed to describe the relationship between precipitation, surface runoff, and shallow groundwater table in a watershed that is subjected to groundwater extraction and urbanization. Regression analysis of fourteen years (1976-1989) of time series data for precipitation, stream discharge, ground water elevation, and groundwater extraction yielded good correlation between these parameters.

Analysis of the data associated with groundwater recharge and discharge events that occurred in the watershed from 1976 to 1989 yielded a high correlation between the above cited parameters. Regression analysis utilized to predict monthly variations in groundwater elevations showed a fair correlation between …

Oodini 2.1 : An Enhanced Graphical Schema Representation For Object-Oriented Database, Rajashekar Rao

Theses

The graphical representation of an object-oriented database (OODB) schema is useful for the designers and users of a database system. The purpose of my thesis was to enhance the existing version of OOdini, an interactive graphical tool for editing an OODB schema. The new features include interactive modification and description of objects in the schema. Data structures for representing classes and attributes have been altered to incorporate object/data types as well as a descriptive string. The software has been implemented using the ObjectMaker toolkit to design our own methodology using the ObjectMaker Extension Language.

Residual Stress Analysis Of Sputtered Tantalum Silicide Thin Film, Young Joo Song

Theses

The influence of different argon pressures on the residual stress, microstructure, and resisitivity of sputtered tantalum silicide thin films has been investigated. TaSi₂ films were deposited onto Si wafers by dc magnetron sputtering. The deposition temperature was assumed to be 300°C. The thickness was about 0.5 μm. The residual stresses in the films deposited at different argon pressures were determined by curvature measurement method. The compressive intrinsic stress of 1033.4MPa was measured at P_Ar = 0.5 mTorr. The intrinsic stress in the films seemed to change from compression to tension as P_Ar increased above 8mTorr. A maximum …

Low Pressure Chemical Vapor Deposition Of Silicon Dioxide And Phosphosilicate Glass Thin Films, Vijayalakshmi Venkatesan

Theses

Silicon dioxide thin films were synthesized on silicon and quartz wafers using Ditertiarybutylsilane(DTBS) and oxygen as precursors. Trimethylphosphite (TMP) was injected to obtain phosphosilicate glass. The films were processed at different temperatures between 700°C and 850°C at a constant pressure, and at different flow ratios of the precursors. The films deposited were uniform, amorphous and the composition of the films varied with deposition temperature and precursor flow ratios. The deposition rate increased with increasing temperature and with increasing TMP flow rate. The stresses were very low tensile in the case of undoped silicon dioxide film and tended towards being less …

Press Performance Of Frequency Modulated Screen Printing On Newsprint, Li-Yi Ma

Theses

Frequency Modulated (FM) screening has been praised for its apparent resolution advantage over conventional halftone screening. Studies showed FM screening can be processed with the existing technology, and it does bring about a visible improvement in image quality on newsprint. This study focused on the press performance of the FM halftone printing on newsprint. The fineness of conventional halftone screens can be described by indicating the screen rulings (lines per inch or lpi), and the fineness of FM screens is measured by the size of the micro dots ([micron] or 10~6m). It is difficult to equate the microdot size in …

A Buffering Strategy For Stabilizing Network Data Rates, Brian Bell

Theses

In the past ten years, there has been substantial growth in the area of networked applications. The expansion of such Internet applications as USENET and the world wide web has lead to greater demand for faster and higher quality data transmissions. However, the Internet tends to have a bursty traffic pattern. Such a pattern interferes with an application's ability to receive a data stream at a constant rate. A constant rate is necessary for real-time, networked multimedia applications to be able to provide a high quality of service to the user. This thesis proposes a buffering strategy that stabilizes a …

Behind And Ahead: The Formally Undocumented Travels Of Egon Schiele To Ireland 1905-1918, Alan Phelan

Theses

None provided.

A Vhdl Model Of A Superscalar Implementation Of The Dlx Instruction Set Architcture, Paul Ferno

Theses

The complexity of today's microprocessors demands that designers have an extensive knowledge of superscalar design techniques; this knowledge is difficult to acquire outside of a professional design team. Presently, there are a limited number of adequate resources available for the student, both in textual and model form. The limited number of options available emphasizes the need for more models and simulators, allowing students the opportunity to learn more about superscalar designs prior to entering the work force. This thesis details the design and implementation of a superscalar version of the DLX instruction set architecture in behavioral VHDL. The branch prediction …

Lei Rimana "She Stays", Keith Watson

Theses

My concept is to re-evaluate and advance personal communication aids, generally, but not entirely, in the form of greeting cards, to a new level of interest and signification. The goal is to eliminate the passive viewer, and have the individual actively participate in the presentation. The computer-based, interactive media project is designed around three-dimensional sculptures, which serve as "narrators," and put back the one-to-one interaction that is so often missing in non-verbal greetings. In combining technology with more traditional storytelling techniques, it will develop and express a personal message that will help reinforce the intent of the message by becoming …

Facial Rejuvenation With Aesthetic Surgeries, Landy Lin

Theses

None provided.

Performance Differences Between White, Black And Hispanic Students, Jessica Gebhardt

Theses

A major criticism of intelligence tests is that they are biased against ethnic minority groups. The purpose of this study was to examine whether culturally different values affect the performance of ethnic minority students on these standardized tests. The records of 21 White, 34 Black and 18 Hispanic students who had been given the WISC-HI were selected and scores on the timed subtests were compared. No significant differences were found between the White, Black and Hispanic groups on the basis of the overall Performance Scale IQ scores. However, the White students' scores on the Verbal Scale were significantly higher than …

A Study Of Presentation Products For The Himedia Soho Environment Of The 21st Century, Mine Ertan

Theses

None provided.

Myth Understanding, Chris Jackson

Theses

"Myth Understanding" is a prototype of an interactive educational program geared towards elementary school children. It provides self-paced instruction, mixing animation, graphics, and sound with information pertaining to earth science. Mythological characters from ancient Greece are sources which provide the child with scientific as well as historic information. In effect, children learn about ancient Greek mythology as they discover the mysteries and makeup of the earth. Children are given the flexibility to decide on what information to view ac cording to their own personal preference. Meticulous attention was given to the artwork interface design and layout. "Myth Understanding" incorporates multimedia …

Hell Vision, Willie Li-Wei Yang

Theses

This thesis is a guided tour of my version of HELL. HELL consist of nine levels and each level has its own storyline. The reason for choosing this subject is because there are no real concrete ideas of HELL and therefore, it is an area that I can truly explore and use my imagination to create an environment that will appeal to the emotions of the users. The overall goal of this thesis is to try to bring out the emotions of fear, frustration, madness, and humor from the users. The secondary goal is to explore the limit of user …

Assessment Of Mixing Parameters To Achieve Stable Sodium Carboxymethylcellulose (Nacmc) Solutions At Vaeying Ionic Strengths Of Nacl, Beverley Waller

Theses

The effect of mixing parameters on sodium carboxymethylcellulose (NaCMC) solutions was studied using three mixing systems. The first utilized a predominantly shear mixer (Ross), the second utilized a predominantly flow mixer (Heller), and the third utilized a combination of the two. It was discovered that the most effective system was the combination of the two mixers. A wide range of solutions was examined, with CMC concentrations ranging from 5 to 21 grams/liter. Salt concentrations were also varied from solutions with no salt to 2.5M NaCl solutions. Based on this data, CMC was found to behave as predicted by the Einstein …

A Petri Net Design, Simulation, And Verification Tool, Richard Brink

Theses

Increasing desire for thorough simulation and analysis of engineered products is quickly replacing the prototype and test design model. Petri nets are important instruments for modeling concurrent, distributed, asynchronous, parallel, deterministic, and non-deterministic systems. This tool provides designers with the ability to easily specify a Petri net design with an easy to use user interface, then simulate and analyze the Petri net to determine essential design properties using the reachability tree technique. The tool will construct a reachability tree, then analyze the tree for properties of safeness, boundedness, liveness, and conservativeness.

Happiness Is Not A Bad Idea, Wataru Okada

Theses

None provided.

Bubble Growth Rate And Heat Transfer Suppression In The Flow Boiling Of Binary Mixtures, Taavo Raykoff

Theses

An investigation is undertaken into the nature of the bubble growth rate and heat transfer suppression in the flow boiling of binary mixtures. From an examination of the well established pool boiling theory available in the literature and a consideration of factors uniquely present in flow boiling situations, it is determined that the present pool boiling theories are roughly applicable for a finite initial interval of the bubble growth cycle during flow boiling. Furthermore, it is hypothesized that the suppression of the increase in heat transfer coefficient in binary fluids which occurs after the onset of nucleate boiling is related …

Modeling Ventricular-Vascular Coupling In The Developing Embryo, Michael Bauman

Theses

Congenital cardiovascular malformations are one of the major contributors to infant mortality in the United States today. Defects in the cardiovascular system are evident at very early stages in the developing embryo, yet there exists no substantial diagnostic tool(s) for recognizing defects at these early stages. Cardiac morphogensis occurs throughout the pre-innervated period of embryonic development. It is speculated that the flow of blood during the early embryonic stages plays an important role in the development of the cardiovascular system. Blood flow is a possible mechanism for communication between the heart and vasculature, contributing to cardiac development. The objective of …

The Figure, Emotion, And Color, Kenneth Kenslow

Theses

None provided.

The Boat As Sculptural Metaphor, Place Scott

Theses

This thesis was undertaken to explore the possibilities of utilizing the boat as a unique form for my own work in the realm of ceramic sculpture. I dealt with the boat as a metaphor to depict personal fantasies, daydreams and past encounters. In these pieces I depict the sense of freedom I feel from skimming across the surface of water. Some appear as though they are in rapids of a river. Another is a depiction of being in the middle of a big body of water and feeling rather small.

The Boat As Sculptural Metaphor, Scott Place

Theses

This thesis was undertaken to explore the possibilities of utilizing the boat as a unique form for my own work in the realm of ceramic sculpture. I dealt with the boat as a metaphor to depict personal fantasies, daydreams and past encounters. In these pieces I depict the sense of freedom I feel from skimming across the surface of water. Some appear as though they are in rapids of a river. Another is a depiction of being in the middle of a big body of water and feeling rather small.