Digital Commons Network^™

Application Of Tube Settlers In Secondary Wastewater Treatment, Abdulsalam Mohamed Saleh Kamalpoor

Theses

Secondary sedimentation is one of the most commonly used unit operations in wastewater treatment plants. It is customary designed to achieve solids separation from biologically treated effluent through clarification of biological solids and thickening of sludge. As treatment plants receive increasingly high wastewater flow, conventional sedimentation tanks suffer from overloading problems which result in poor performance. Inclined plate settlers, a form of tube settlers, may have good potential in upgrading sedimentation tanks. This study was conducted to examine the possibility of applying inclined plate settlers in secondary sedimentation in order to upgrade conventional rectangular sedimentation tanks and improve their performance. …

Environmental Management And Treatment Of Oily Water In Abu Dhabi Offshore Oil Fields, Mohamed Ali Saeed Al-Nuaimi

Theses

The purpose of this environmental case study is to evaluate the oily water treatment efficiency in the separation of oil from water in relation to the environmental impact to the marine environment. This study covers offshore oil fields production facilities in the Abu Dhabi Emirate. The study discusses the most commonly used methods in the separation of oily water disposals. It highlights in detail the different types of treatment systems currently in use at Abu Dhabi offshore oil fields production facilities. Emphasis is given to the performance of each treatment system, its deficiencies and possible areas of improvement.

The study …

Endovascular Technology: The Palmaz Intravascular Stent And The Auth Rotablator, Thomas Barg

Theses

None provided.

Super Scalar High Speed 2(Mew) N-Well Mosis Cmos Digital Halftoning Processor, Anupam Gupta

Theses

Digital halftoning is the algorithmic process for converting electronic images into bitonal images that preserves the perception of a continuous-tone image. Various digital halftoning algorithms were considered in the development of this processor on the basis of quality of image and amenability for VLSI implementation. An error-diffusion algorithm with the options of noise encoding, printer model adjustment, and edge enhancement was chosen for implementation. Since the algorithm allows for multiple independent parallel processors to operate on the same image, the system is capable of super scalar processing. The processor is intended for an 8-bit input (256 gray levels). The processor …

Bringing Ideas Back To The Evolution Of Design, Ayca Tuzmen

Theses

This thesis is an exploration into the evolution of design. It attempts to develop an awareness of the effectiveness of what we do as designers and users to improve design. To achieve this purpose, it elaborates on some of the implications of paradigms which have emerged in design evolution. It presents some of the evolutionary theories and their analogies. These theories and analogies develop a view of design evolution - a conception of design as a process which moves from a lower to a higher state. With this conception, concern is directed at the identification of past and current design …

Degradation And Breakdown In Ultra-Thin Silicon Oxides, Christopher Franck

Theses

Emerging trends in the semiconductor device industry call for detailed knowledge of the properties of devices whose dimensions are small enough to exploit Quantum Mechanical effects. This thesis presents a complete picture of oxide degradation in MOS direct tunnel diodes (t0 <3.4 nm). It is demonstrated that for structures fabricated at different facilities and stressed with either gate or substrate injection, a universal degradation mode is revealed which is manifested as the build up of positive charge in the oxide. The data gathered demonstrates that the positive charging phenomena in sub-3.5 nm oxides is independent of oxide thickness, and is characterized by a voltage threshold and two-regime temperature dependence. Further, the catastrophic failure, or breakdown, of these oxides was studied and the strongest evidence to date is presented which links the positive charging phenomena to the oxide breakdown. This thesis concludes with the presentation of a novel device design which can exploit the properties of degradation and breakdown, in thin oxides, to achieve an EEPROM memory cell of superior endurance.

Removal Of Vocs From Waste Gas Streams By Cyclic Membrane Separation Techniques, Gordana Obuskovic

Theses

In this study, new separation techniques called Flow Swing Membrane Absorption Permeation (FSMABP) and Flow Swing Membrane Permeation (FSMP) were used for the removal of the volatile organic compounds (VOCs). In both cases, processes are cyclic in terms of feed flow while desorption of the VOCs is constantly taking place. The transport mechanism in the FSMABP process is selective permeation followed by absorption of the VOCs into the stagnant nonvolatile absorbent liquid on the shell side of the membrane module and then desorption through a similar polymeric membrane. In the FSMP process, VOCs selectively permeate through the membrane into the …

Dynamic Mechanical Analysis Of Particulate Dental Composites, Minu Parekh

Theses

Typically, dental composites are used in different configurations and situations. When a cavity forms at the occlusal surface of a posterior tooth, a class I and class II filling is used, depending on the extent and nature of the cavity formed. These fillings have to be designed to resist mechanical abrasion and occlusal stress during chewing, bruxing and other tooth functions. Class IV fillings are also designed to resist biting stress. In these applications composites with high filler loading with filler particles of size >0.6μm are used. These composites are typically known as minifill or midifill composites. When more than …

A New Concept In Artificial Ligament And Tendons Modeling : Finite Element Analysis, Miroslaw Sokol

Theses

Reconstruction of the Anterior Cruciate Ligament (ACL) has been a major focus in sports medicine for over twenty years. Severe or unrepairable damage of the ACL due to sport injury is a major problem faced by orthopedic surgeons and engineers. To successfully replace or reconstruct an injured ACL, the mechanical properties as well as the dimensional limitation of the material used must be similar to the biological ligaments. Although excessive literature describes experimental investigation on the mechanical property and clinical application of the ligament material, there is no analytical study that describes strains, stresses, and endurance in the bone/ligament/bone complex. …

Usability Of Hypertext : Factors Affecting The Construction Of Meaning, Kathryn L. King

Theses

One type of hypertext application, information retrieval, has become increasingly popular and accessible due to the explosion of activity occurring on the World Wide Web. These hypertext documents are referred to as web sites. Readers can now access a multitude of web sites and retrieve a wide variety of information.

The uniqueness of a hypertext document centers around the concept that text is broken into an array of non-sequential text chunks, or nodes, which are connected through links. The hypertext reading can be considered an interactive experience requiring the reader to effectively navigate the document. The potentially complex link and …

The Study Of Sige-Channel Heterojunction Mos Device, Yunchen Qiu

Theses

The advances in the growth of pseudomorphic silicon-germanium epitaxial layer combined with the strong need for high-speed CMOS VLSI circuit have led to increased interest in silicon-based heterojunction MOSFET's transistors. The high-performance heterostructure SiGe MOSFET exhibits higher channel mobility than its bulk Si counterpart. The most critical and challenging process for fabricating a SiGe MOSFET device is that for making a gate oxide with sufficient quality for useful conductivity modulation. PECVD methods was employed to deposit the gate oxide and C-V method was used to investigate the electrical characteristics of the film. For PECVD gate oxide, a film refractive index …

Pollution Prevention In The New Jersey Chemical Industry : Motivations And Barriers To Commitment, Judith A. Thornton

Theses

This study of the New Jersey Chemical Industry identifies the primary elements that lead to or inhibit company commitments to pollution prevention. A direct measure of facility pollution prevention commitment is developed that takes into account: organizational support attributes, past reductions achievements, current methods implementation, process reduction goals, and special environmental initiatives. The "P2 Commitment Index" allows for categorization of facilities so that the needs and interests of varying groups may be differentiated.

Higher level commitments are associated with: establishment of company pollution prevention policy, setting of prioritized facility goals, and measurement and reporting on pollution prevention progress. Facilities at …

A Digital Signal Processor Based Optical Position Sensor And Its Application To Flexible Beam Control, Thomas J. Spirock

Theses

A Digital Signal Processor (DSP) based optical position sensor was developed. The sensor system consists of the following components: 1) analog electronics, 2) the DSP based synchronous demodulation software, 3) PC based interface software which samples and saves the data, and 4) PC based control codes for a flexible beam. experiment.

The ability of the system to determine the distance from the optical sensor to the power modulated light source was assessed by the following tests: 1) a stationary drift test to evaluate the system's noise, 2) a short-range test to determine the resolution of the optical sensor over a …

The Reactions Of Nox With Diesel Soot Over Cu-Zsm-5 Catalyst, Shu Sun

Theses

Air pollution from the exhaust of Diesel engines consisting of relatively high concentrations of NO_x and particulates is a difficult problem to overcome because no fully effective technology to control these emission is available. The existing methods to reduce NO_x and soot can not satisfy the provisions of the 1990 CAAA (Clean Air Act Amendment). Cu-ZSM-5, a catalyst in which Cu has been ion-exchanged with H+, can catalyze the decomposition of NO to N₂ and O₂ and reduction to N₂ and O₂ with light hydrocarbons such as propene or Diesel soot in the presence …

Oxidation Of Isobutane And Isobutene Reaction Pathways And Detailed Mechanism, Chiung-Ju Chen

Theses

A reaction mechanism consisting of 248 elementary reactions and 138 species has been developed to model experimental systems - decomposition of 2,2,3,3 tetramethylbutane in the presence of oxygen and oxidation of isobutene. This elementary reaction mechanism based on two important reaction systems: tert-butyl radical with O₂ and allylic isobutenyl radical with O₂, plus their subsystems, such as isobutene + HO₂, isobutene + OH and allylic isobuteny1hydroxy + O₂. Thermochernical kinetic parameters are developed for each elementary reaction and a chemical activation kinetic analysis using quantum RiceRamsperger-Kassel (QRRK) theory for k(E) and modified strong …

Measurement Of The Electroencephalogram (Eeg) Coherence, Atmospheric Noise, And Schumann Resonances In Group Meditation, Douglas A. Newandee

Theses

Electrical activity in the human body was investigated using EEG and ECG measurements while subjects remained with eyes open, eyes closed and in a meditation state. During these measurements, additional antennas were attached to the equipment to record atmospheric noise and signal activity simultaneously. The obtained data was analyzed and various observations were made. Processed data based on antenna signals clearly showed the presence of man-made signals, having narrow spectral widths that could be treated as atmospheric noise in the frequency range up to 50 Hz. In addition, signals clustered around 7.8, 14.1, 20.3, 26.4, and 32.5 Hz were observed …

Comparison Of Different Signal Processing Algorithms To Extract The Respiration Waveform From The Ecg, David J. Caggiano

Theses

Power spectral analysis of heart rate variability is a powerful tool to measure the activity of the parasympathetic division of the autonomic nervous system noninvasively. To determine the parasympathetic activity, the frequency of respiration must be known. However, during ambulatory studies, the frequency of respiration is not acquired. To alleviate this problem, methods have been proposed in the past to derive the respiration from the ECG. Unfortunately, these previous methods are unreliable if the subject's breathing rate is uncontrolled. In this study, four methods to derive the respiration waveform from the electrocardiogram (ECG) were developed. Two leads of ECG and …

Stratospheric Ozone Layer Depletion : A Computer Aided Case Study, James M. Lipuma

Theses

In industries today, there is a desire to stop pollution before it starts, through the process of pollution prevention. Unfortunately, many university level students are not exposed to the thinking process involved in environmental problem solving early enough in their academic career, if they are exposed to it at all. The goal of this thesis is to develop and to evaluate an interdisciplinary case-study about the depletion of the stratospheric ozone layer by chlorofluorocarbons (CFCs). This case-study will be used to teach first year chemistry students about environmental problem solving. The case study was assembled from existing literature according to …

Advanced Characterization And Leaching Behavior Of Hexavalent And Trivalent Chromium From Waste Material, Erik Moerman

Theses

In this thesis we employed advanced characterization techniques such as XRF, XRD, XPS, SEM, and EDS to provide detailed information about the chromium waste _ specifically chromium valence states (Cr(VI) and Cr(III)), and their chemical association with other phases in the waste matrix.

The removal of Cr(VI) was accomplished by leaching with aqueous solutions containing inorganic anions such as Cl^-, SO₄^2-, PO₄^3- and others. Cr(VI) can be released from the waste by a combination of desorption and ion exchange processes. The efficiency and kinetics of displacing CrO₄^2- from the waste by …

A Mathematical Model Of Cardiovascular System With Feedback Control, Jiayu Gu

Theses

A mathematical model of human cardiovascular system is presented in this study. The closed-loop model is composed of twenty compartments which includes the left and right ventricles, and the systemic and pulmonary circulations. Two physiologic feedback control mechanisms, autoregulation of blood flow and baroreceptor reflex regulation of arterial pressure, are incorporated in the model. Autoregulation acts by changing local resistance to blood flow through metabolic and myogenic mechanisms, thereby insuring a match between oxygen supply and demand for any tissue or organ. Baroreceptors act through neural pathways to alter heart rate, contractility and peripheral resistance in order to return sudden …

Relay Ladder Logic And Petri Nets For Discrete Event Control Design : A Comparative Study, Edward Twiss

Theses

In the 1960's and earlier discrete event systems (DES) were controlled by hardwired electromechanical relay systems. In 1969 an electronic programmable logic controller (PLC) was introduced. PLC's have been programmed utilizing relay ladder logic (RLL). RLL is a graphical programming language with software "devices" used to emulate electromechanical devices. RLL programs, however, often become large and difficult to understand because its graphical representation of physical switching devices obscures the discrete event dynamics inherent in the process to be controlled. Petri nets are a methodology for modeling discrete event systems (DES). Using a Petri net based controller, a control strategy could …

Environmental Communication : Theory And Practice, Mary Mccarney Mcmanus

Theses

The present study examines the relationship between environmental communication theory and practice. The focus of the case study is to examine the formal elements of an environmental document--the Industrial Pollution Prevention Planning guidelines published by the New Jersey Department of Environmental Protection (NJDEP)--and the process by which this document was created. This study of product and process allows a methodology to be developed by which the complexities of environmental communication may be better understood.

Development Of A Fiber Optic Polarimetric Sensor For Concrete, Insang Lee

Theses

Development of a fiber optic sensor for embedment in cementitious composites and measurement of displacements associated with the opening of microcracks is described. The sensor can be employed as a transducer for measurement of crack tip opening displacements during fracture tests. A polarization maintaining fiber is used as the sensing element, and transduction mechanism is similar to those of other polarimetric type based sensors. However, the deformation resolving power of the sensor is increased by way of increasing the effective length of the optical fiber. This is done by winding the optical fiber into a coil. A direct relationship between …

Remote Measurement Calibration In Power System, Xiaofeng Li

Theses

Power system reliability and economy of operation require accurate measurements of current, voltage, real and reactive powers. These measurements are transmitted to a control center of a power system for monitoring, display, and use in power system real-time analysis. The number of measurements is in thousands. Routinely field technicians must calibrate transducers and/or determine other sources of metering errors. Due to the large number of measurements and the time required to check each individual measurement, field calibration procedures are impractical, expensive, and not timely.

There has been a need for a more efficient approach to measurement calibration and identification of …

Speciation And Determination Of Trace Lead : Methodology Development And Analysis Of Natural Waters Using Chelex-100 And Gfaas, Xidan Ma

Theses

The development of a method for speciation, preconcentration, and determination of lead was successfully conducted using Chelex-100 and graphite furnace atomic absorption spectroscopy (GFAAS). Sorption under static conditions and direct measurements in the bead slurry or after fast elution of lead from beads with HNO3 solution was used. The effects of buffers, sorption kinetics, filtration criteria, sample concentration, resin particle size and temperature program for the GFAAS were carefully studied. In this study, synthetic aqueous samples containing lead were preconcentrated under static conditions using the ion exchange resin, Chelex-100, and the resin was directly analyzed using GFAAS. The batch preconcentration …

Validation Of A Mathematical Model Of The Human Walking Cycle Using Parameter Identification Methods, Robert Mccann

Theses

A mathematical model of the swing phase, toe-off and heel strike is presented in this paper and is mathematically represented as a two dimensional, simple coupled pendulum system with three degrees of freedom. Lagange equations of motion are used to solve this highly idealized system. The model consists of three segments which represent the stance leg, thigh and shank. During the swing phase it is assumed that the only external forces acting on the system are gravity and viscous dissipative terms proportional to joint angular velocities. It is assumed that muscle forces act only to establish the initial limb segment …

A Theoretical And Empirical Analysis On Efficiency Of The Foreign Exchange Markets : An Empirical Evaluation Of The British Pound, French Franc And Canadian Dollar Testing For Cointegration And Unbiasedness, Panagiotis Paleologos

Theses

This paper discusses the important aspects of efficiency, expectations, and risk in the foreign exchange market. First, a brief presentation of the existing single-equation structural models of exchange-rate determination is given. A mathematical efficiency specification model is defined which employs of a system of interrelated equations testing the random walk and unbiasedness hypothesis. The model is validated by analyzing fluctuations in the spot and forward foreign exchange rates. Utilizing a regression estimation and many different specification and diagnostic tests for the series and the error terms (residuals), this study addresses the efficiency of the English, Canadian and French foreign exchange …

Plasma Enhanced Chemical Vapor Deposition Of Stress Free Tungsten Films, David Perese

Theses

This study focuses on PECVD to make tungsten film for X-ray absorber for use in X-ray lithography applications. The previous LPCVD study was used for comparison of film properties. A cold wall, single wafer, Spectrum 211 CVD reactor was used for the deposition of tungsten from H2 and WF6. The growth kinetics were determined as a function of temperature, pressure and flow rate ratio. The deposition rate was found to follow an Arrehnius behavior between 300-500°C with an activation energy of 55.7 kJ/mol. The growth rate increased linearly with total pressure and H2 partial pressure. In the H2/WF6 ratio studies …

Mass Transfer Of Pryene Between A Solid Phase And Oil/Water Suspensions, Sachin Ashok Purekar

Theses

This study dealt with understanding the partitioning of pyrene between water and mineral oil, and the mass transfer of pyrene from solid particles to oil/water suspensions.

It was found that when pyrene is dissolved in mineral oil, the amount transferred to water is negligible even after 10 days of phase contact.

Glass beads and sand were used as model solid phases to simulate soil and PAH (pyrene)-contaminated industrial sludges.

The transfer of pyrene from glass beads to mineral oil when no water phase is present was quantified. Mass transfer coefficients, and their dependence on the rate of environment shaking were …

Separation Of Polycyclic Aromatic Hydrocarbons By Using Micellar Electrokinetic Chromatography, Patricia Simmons

Theses

In this work, the use of micellar electrokinetic chromatography (MEKC) for the separation of five polycyclic aromatic hydrocarbon (PAH) compounds is investigated. All of the compounds studied are listed by the United States Environmental Protection Agency as priority pollutants.

In micellar electrokinetic chromatography, solutes partition between the aqueous phase and the micellar phase. This partition is based on the hydrophobicity of each compound. In some cases, organic modifiers are added to the electrophoretic solution to enhance the separation efficiency. The organic modifier used in this study is y-cyclodextrin (y-CD), and sodium dodecyl sulfate (SDS) is used as the micellar phase. …