Engineering Commons^™

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 …

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 …

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 …

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 …

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 …

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. …

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. …

Granular Dynamics Study Of Sieving, Heng Yung

Theses

The objective of this thesis is to study the behaviors of granular particles under sieving. A three-dimensional dynamic simulation code was transferred and modified for this purpose, The major concern is the mass flow rate of the particles. Lots of case studies were run. The influences of the friction coefficient, the sieve aperture, and the energy of vibration are studied.

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 …

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 …

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 …

On The Adaptive Multi-Stage Detector For Cancellation Of Multiuser Interference In Cdma Wireless Communication Systems, Nadir Sezgin

Dissertations

The classical multiple access techniques such as Frequency Division Multiple Access (FDMA) and Time Division Multiple Access (TDMA) schemes are band limited in terms of their capacity to be used for mobile radio communication. Recent developments in the area of digital signal processing, makes Code Division Multiple Access (CDMA) as a possible solution to the demand of capacity for the mobile radio communication. The capacity of CDMA is limited by multiuser interference, that is the interference from the other users.

The goal of this dissertation is to improve the multiuser CDMA detector with high Bit Error Rate (BER) performance, low …

Real Time Control Of Nonlinear Dynamic Systems Using Neuro-Fuzzy Controllers, Amitava Jana

Dissertations

The problem of real time control of a nonlinear dynamic system using intelligent control techniques is considered. The current trend is to incorporate neural networks and fuzzy logic into adaptive control strategies. The focus of this work is to investigate the current neuro-fuzzy approaches from literature and adapt them for a specific application. In order to achieve this objective, an experimental nonlinear dynamic system is considered. The motivation for this comes from the desire to solve practical problems and to create a test-bed which can be used to test various control strategies. The nonlinear dynamic system considered here is an …

Investigation Of Dynamic Friction In Lubricated Surfaces, Hanuman Rachoor

Dissertations

The research reported in this dissertation is concerned with the development of friction models for lubricated contacts. A few analytical models have been developed to investigate the friction under dynamic velocity conditions. In this study, two different tribological situations such as conformal and non-conformal contacts have been chosen. Friction modeling covers boundary, mixed and full fluid film friction regions. A new theory based on the elastic properties of the surface materials, and fluid film properties of the lubricant at the contact has been developed to determine the dynamic friction in boundary, mixed and full hydrodynamic lubrication regions. In the full …

Adaptive Space-Time Processing For Wireless Communications, Xiao Cheng Bernstein

Dissertations

Adaptive space-time processing techniques have been found to increase the capacity of two major, multiple-access wireless communication systems: Time Division Multiple Access (TDMA) and Code Division Multiple Access (CDMA).

In an IS-54 TDMA system, the frequency re-use factor has to be set to 7 so that cells with the same spectrum are separated far enough to meet a required carrier-to-interference ratio (CIR). Space processing uses multiple antennas which, in turn, provide alternative signal paths in order to cancel interferences and combat multipath fading. We have proposed the eigencanceler method and have reviewed the theoretical optimum combining and the feasible direct …

On Optimal Design And Applications Of Linear Transforms, Mehmet V. Tazebay

Dissertations

Linear transforms are encountered in many fields of applied science and engineering. In the past, conventional block transforms provided acceptable answers to different practical problems. But now, under increasing competitive pressures, with the growing reservoir of theory and a corresponding development of computing facilities, a real demand has been created for methods that systematically improve performance. As a result the past two decades have seen the explosive growth of a class of linear transform theory known as multiresolution signal decomposition. The goal of this work is to design and apply these advanced signal processing techniques to several different problems.

The …

On The Optimization Problems In Multiaccess Communication Systems, Gangsheng Wang

Dissertations

In a communication system, the bandwidth is often a primary resource. In order to support concurrent access by numerous users in a network, this finite and expensive resource must be shared among many independent contending users. Multi-access protocols control this access of the resource among users to achieve its efficient utilization, satisfy connectivity requirements and resolve any conflict among the contending users. Many optimization problems arise in designing a multi-access protocol. Among these, there is a class of optimization problems known as NP-complete, and no polynomial algorithm can possibly solve them. Conventional methods may not be efficient arid often produce …

Anaerobic Digestion And Acid Hydrolysis Of Nitrocellulose, Fong-Jung Tai

Dissertations

In this investigation, studies were conducted to evaluate the biodegradation of nitrocellulose in anaerobic batch reactors with and without the supplemental carbon inducers, such as cellulose, cellobiose, and lactose. Results from the anaerobic study show that degradation of nitrocellulose alone is difficult and that nitrocellulose degradative enzymes could be induced by the three inducers tested. As high as 48.91% conversion could be obtained at Cellulose/Nitrocellulose ratio of 1 to I. Studies also indicated that type 20 and 50 celluloses would be more effective and optimum pH was about 6.4 in biodegradation of nitrocellulose. Three testing systems, namely, single-stage, two-stage, and …

An Investigation Of The Mechanism Of Advanced Oxidation Processes (Aop) Involving Free Radicals And Charged Species., Yaw-Kuen Lin

Dissertations

Hydrogen peroxide is a key component in Advanced Oxidation Processes (AOP). Its decomposition at different pH conditions has been studied and some interesting results were observed. When the pH value of hydrogen peroxide solution is less than 9, its rate of decomposition is independent of pH. On the other hand, in the pH range of 9-12.6, its rate of decomposition increases as pH increases, and goes through a maximum value then suddenly decreases with respect to pH. A reaction kinetic model with three rate constants in the form of beta probability function was used to describe the experimental data of …

Numerical Simulation Of Clipping Distortion In Lightwave Catv Systems, Luay Al-Nadi

Theses

Clipping induced distortion is an essential limit for modulation depth and number of channels in subcarrier multiplexed lightwave video transmission systems. Two different types of laser clipping are compared (single-clipping vs. double-clipping). In this work, the distortion limits imposed by clipping effects, in both directly (single-clipping) and externally (double-clipping) modulated systems, are examined. Numerical simulations were performed to test the efficiency of Saleh's Model. A comparison of results with clipping induced distortion in directly modulated lightwave systems (single-clipping) and clipping induced distortion in externally modulated lightwave systems (double-clipping) is presented, it is shown through numerical simulation that the total non-linear …

Integrating Key Functions In Product Development : A Conceptual Product Development Model For The Korean Context, Jong-Wook Kim

Theses

The high-tech market is characterized by market uncertainty, technology uncertainty and rapid change. To survive in this risky high-tech market, a company must create competitively effective product development practices that meet its own unique needs and circumstances.

One effective practice is cross-functional integration in the product development process. The advantages of integration include a shortened time to market, successful transformation of research results to production, productivity improvement, innovation project success, and high-quality problem solutions. However, these advantages are rarely obtained in the current product development practices of Korean companies. Their product development efforts are generally characterized by time consuming sequential …

Gabor Expansion Of An Equivalent Dipole Antenna, Oksana Manzhura

Theses

The Gabor representation in the context of an aperture problem is an expansion of a radiated field in terms of a discrete set of linearly shifted and spatially rotated elementary Gaussian beams. The parameters that can be varied in this summation are the number of beams and corresponding beam widths. As the difficulty associated with the unique determination of the expansion coefficients was alleviated, the method has been successfully applied to one and two dimensional apertures. Although, the asymptotic evaluation of expansion functions has reduced the computational burden drasticallym it was at the expense of some loss in accuracy. The …

Signal Processing Techniques In Heart Rate And Systolic Arterial Blood Pressure Variability Studies, Christopher O'Bara

Theses

Power spectral analysis of heart rate and systolic arterial blood pressure variability provides a window to the activity of the autonomic nervous system. To derive power spectra from raw blood pressure and electrocardiogram signals, many steps of signal processing must be performed. Most popular methods of spectral analysis require evenly spaced samples; therefore interpolation and resampling techniques must be used.

The results of the present study indicate that different interpolation techniques result in spectral distortions that vary depending upon the interpolation methods used as well as physiological parameters such as heart and respiration rate. Different interpolation methods applied to heart …

Design And Development Of Four To Sixteen Channel Video Multiplexers, Ronan Rahimi

Theses

Video multiplexer series were successfully designed and built for prototype and evaluation both in terms of hardware and software. The hardware platform was designed to accommodate up to sixteen color video input channels for time lapse or real time recording on a single video cassette recorder. This product implements four modes of operation; Live, Record, Playback and Menu mode, which is not a full mode of operation. Menu mode is a series of on-screen programming menus which appears on Live, Record and Playback modes. Menu mode enables the user to program the machine to work under specific modes of application. …

Configuring The Radial Basis Function Neural Network, Insoo Sohn

Theses

The most important factor in configuring an optimum radial basis function (RBF) network is the training of neural units in the hidden layer. Many algorithms have been proposed, e.g., competitive learning (CL), to train the hidden units. CL suffers from producing "dead-units." The other major factor Which was ignored in the past is the appropriate selection of the number of neural units in the hidden layer. The frequency sensitive competitive learning (FSCL) algorithm was proposed to alleviate the problem of dead-units, but it does not alleviate the latter problem. The rival penalized competitive learning (RPCL) algorithm is an improved version …

Linearly Tapered Slot Antenna, Luis Alberto Tumialan

Theses

Design procedure for Linearly Tapered Slot Antennas (LTSA) has been developed and implemented using High Frequency Structure Simulator (HFSS) code based on a finite-element analysis.

A CAD study of two variations of a LISA based on either a stripline or a microstrip feed has been carried out. Circular and radial stubs have been considered in these designs for an antenna operating at 10 Ghz. LTSA on a Duroid substrate fed by a stripline has been designed to operate with better than 12 dB return loss. Fabricated antenna was characterized and had even a wider response than the CAD design. Radiation …

Remediation And Reuse Of Chromium Contaminated Soils Through Cold Top Ex-Site Vitrification, Wiwat Kamolpornwijit

Theses

More than 150 sites in Hudson County, New Jersey are identified as chromium contaminated sites. Hexavalent chromium, highly soluble in water, is considered as an environmental and health hazard, classified as a group A human carcinogen. In this research, the feasibility was performed to study the possibility of remediation of chromium contaminated soil by ex-situ vitrification and to evaluate reuse potential of vitrified products as highway construction aggregate. A series of physical and chemical analysis was conducted on nine soil samples collected from different chromium contaminated sites. Results were analyzed for their compatibility for vitrification. Sand and carbon were added …

Comparison Of Adaptive Radar Algorithms : Transformed Smi, Eigencanceler, And Smi, Chaitanya H. Kathiari

Theses

Advanced airborne radars must perform target detection in the presence of interference and heavy clutter. In many applications, the practical usefulness of adaptive arrays is limited by their convergence rate. In this paper, we first analyze the performance of the SMI method. Then, two other methods, the transformed SMI and the eigencanceler, both based on the principle component inversion (PCI) technique, are described and analyzed by simulation. It is shown by simulation based comparison that the transformed SMI and the Eigencanceler outperform the SMI method. It is also shown that the transformed SMI and the eigencanceler has higher convergence rate …