Engineering Commons^™

Spatial Resolution And Biliary Tissue Classification Properties Of A Near Infrared Light Imaging Probe, Praveen Kumar Gulaka

Bioengineering Theses - Archive

Approximately 500,000 Gallbladder Surgeries or Laparoscopic Cholecystectomies are performed annually to remove the Gallbladder. This surgery becomes necessary due to formation of gall stones. As biliary tract tissues are embedded in fat, differentiating them from neighboring tissues and blood vessels is critical in helping surgeons during laparoscopic cholecystectomy to avoid post-surgical complications. Optical spectroscopy (in both visible and near infrared regions) is investigated as a possible technique to identify biliary tract tissues and blood vessels. Such reflectance measurements provide information of effective attenuation, which is an index of optical properties of the tissue.Specifically, optical reflectance measurements were made on biliary …

Experimental And Field Monitoring Studies On Recycled Materials As Pavement Bases, Sunil Kumar Sirigiripet

Civil Engineering Theses - Archive

Natural aggregates derived from a variety of source rocks have been used as a road base material. But the extraction of natural aggregates resources is increasingly being constrained by urbanization, increased costs and environmental concerns. Thus, increased amounts of reclaimed materials are being used to supplement natural aggregates in road construction. Recycled Asphalt Pavement (RAP) material is one of the important recycled materials used in the present geotechnical applications. Many agencies are constantly seeking to reap the benefits of utilizing RAP. Main advantages of utilizing RAP include the preservation of the existing profile, conservation of asphalt and aggregate resources, conservation …

The Travel Behavior Of Minority Cohorts In Texas, Gustavo A. Jimenez Vera

Civil Engineering Theses - Archive

Texas is changing dramatically; the most conservative population forecast indicates that Hispanics will account for 50% of the Texas population before 2035. Not only is the number of Hispanics on the rise in Texas, but also the foreign-born share has increased dramatically over the last 15 years. The State of Texas is now a majority minority state, and minority cohorts are expected to grow and become more than 65% of the Texas population before 2035. Transportation professionals in the State of Texas are wondering how these demographic changes will affect the transportation system. To gain an understanding of this, one …

Cmos Vco & Lna Implemented By Air-Suspended On-Chip Rf Mems Inductors, Varun K. Shenoy

Electrical Engineering Theses - Archive

In this thesis, a CMOS 2.4 GHz Low noise amplifier (LNA) and Voltage-controlled oscillator (VCO) was designed and simulated. These circuits were designed to operate in the 2.4GHz Industrial Scientific Medicine (ISM) band and to achieve Bluetooth and Wifi standard specifications. High-Q RF MEMS air-suspended circular spiral inductors are used in both circuits. High-Q inductors give the circuit better performance parameters including higher gain, lower noise figure and narrower bandwidth. The integration of these RF MEMS inductors onto RF circuit chips was carried out using the UV-LIGA technique and an additive pattern transfer technique such as electroplating. The LNA maintains …

Spatially Resolving Spectrometer For Characterisation Of Broad-Area Laser Diodes, Sheldon Fernandes

Electrical Engineering Theses - Archive

The mode pattern of the BALD (Broad-Area Laser Diode) is characterized and measured using a 1-GHz resolution double-pass spectrometer. The design of spectrometer allowed also a spatial discrimination with 1mkm resolution. The construction and design of the double-pass grating is analyzed and discussed. A matrix approach is developed for the double-pass measurement arrangement. The developed procedure of analysis of spatially resolved spectra provides unique information about broad-area laser diode active medium and cavity geometry and potentially will help to predict the reliability of the laser diode. The developed model is based on paraxial approximation. The laser diode modes are measured …

Fabrication Of A Silicon Single Electron Transistor, Sharukh Roomy Chinoy

Electrical Engineering Theses - Archive

Single electronics has bright prospects because of its high scalability. The single electron transistor (SET) which utilizes these principles could replace the current workhorse of the industry, the MOSFET. The SET is plagued with limitations such as, a low operating temperature, background charge issues, a low voltage gain and high output impedance. The current generation SET devices have overcome most of the aforementioned issues but use highly complicated fabrication techniques. Electron beam lithography was used to pattern device structures on silicon-on-insulator (SOI) wafers with a hydrogen silsesquioxane (HSQ) system being the resist. The silicon was then etched using HSQ as …

A Potential Field Approach To Multiple Robot Formation Control, Rohit Santosh Talati

Electrical Engineering Theses - Archive

A special case of cooperative control for mobile robots is considered - formation control. A potential field based algorithm is developed in which geometric, communication and information centric influences are considered and allowed to deform the formation. Control is accomplished in a leader-follower(s) method. One leader robot defines the overall trajectory and follower nodes individually and autonomously maintain the formation while simultaneously moving toward a goal position. The particular nodes considered are the ARRIbots developed at the Distributed and Intelligence and Autonomy Lab (DIAL) in the Automation and Robotic and Research Institute (ARRI), which are non-holonomic differential-drive wheeled robots. In …

Miso Damping Controller Design For A Tcsc Using Particle Swarm, Swakshar Ray, Ganesh K. Venayagamoorthy, Balarko Chaudhuri, Rajat Majumder

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents a new approach for designing multi-input-single-output (MISO) damping controller for a TCSC in a multi-machine power system. The damping controller design uses particle swarm optimization (PSO) to determine the coefficients of single or multi-stage lead-lag compensators. The classical technique works well in the design of lead-lag compensators for SISO controllers. But, there is no proper step-by-step procedure to achieve the desired performance characteristics for a MISO controller. Hence, in this paper, a computational optimization tool has been used to determine the optimal gains and time constants of a linear MISO damping controller. The damping controller is implemented …

Characterization Of A Hyperspectral Imager: A Diagnostic Tool For Monitoring Retinal Diseases, Nirad Zinzuwadia

Bioengineering Theses - Archive

We developed a novel hyperspectral slit lamp ophthalmoscope for visualizing vascular changes for clinical monitoring of retinal diseases, for example, diabetic retinopathy. The device consists of a visible charge couple device, CCD, and liquid crystal tunable filter, LCTF, coupled to the standard clinical slit lamp ophthalmoscope. The LCTF is used as a spectral light source illuminating the retina with different wavelengths of light that are recorded by the CCD and stored as a series of wavelength dependent images of the retina. Chemometric analysis produces a gray scale encoded image for the percentage of oxyhemoglobin at each pixel within the field …

Roadway Shallow Water Flow Modeling By Velocity Distribution, Chirakarn Sirivitmaitrie

Civil Engineering Dissertations - Archive

Manning's equation is a widely used method for determining flow discharge in a channel with unconfined gravity flow. The roughness value, n-value, is a critical factor for Manning equation to obtain the accurate amount of flow. A precise estimation of Manning "n" is difficult to obtain and varies by investigator justification and experience. Flow on a roadway is a type of open channel flow normally determined by Manning's equation. To ensure reliability and highway safety, the hydraulic geometry dimensions such as spread, depth and discharge must be accurately estimated. A Texas Department of Transportation Manning n-value research project collected data …

Discrete Event Controller: Application Using Dynamic Resource Allocation, Abhishek Trivedi

Electrical Engineering Theses - Archive

This work consists of developing a Discrete Event Controller with Dynamic Resource Allocation, simulating it and than applying it on a test-bed using robots and static sensor nodes. These are the contributions made: 1. Interfacing the Garcia robot with Mica2/Cricket Sensor. 2. Implementing Obstacle Avoidance and Path planning on Garcia Robot for navigational purposes. 3. Localizing the Garcia Robot with the help of Cricket sensor and controlling it from the Base Station to perform assigned tasks. 4. Simulating a Discrete Event Controller which dynamically coordinates multiple missions and simultaneously performing dynamic resource assignment and solving any shared resource conflicts. 5. …

Optimized Class-E Rf Power Amplifier Design In Bulk Cmos, Tao Wang

Electrical Engineering Theses - Archive

The telecommunication market calls for the integration of complicated wireless applications. To build RF power amplifiers in CMOS remains challenging due to the nonideal effects in CMOS. The aim of this thesis is to provide an optimized yet explicit design method for the Class-E amplifiers in CMOS. Taking the finite DC feed inductor into consideration, a simple but accurate numerical design method is proposed by applying polynomial interpolation. Combining with a practical design stategy for nonideal transistors of finite conductance and parasitic capacitances, a two-staged Class-E power amplifier is implemented in 0.18um CMOS. The simulation results show that this power …

Detection Of Positive Cancer Margins Intra-Operatively During Nephrectomy And Prostatectomy Using Optical Reflectance Spectroscopy, Disha Laxman Peswani

Bioengineering Theses - Archive

In recent years optical spectroscopies have become the basis for popular research activity directed towards the development of novel, noninvasive technologies for tissue diagnostics. The motivation for my research was to eliminate the need for surgical removal of tissue samples for biopsy and histology. With the help of an optical probe placed on or near the surface of the tissue, Near Infrared (NIR) spectroscopy can provide diagnostic signatures, non-invasively and in real time. While the ultimate goal vi is the elimination of the need to remove tissue samples, this technology can also be used to provide additional guidance during laparoscopic …

Foreign Body Reactions To Neural Implants In The Brain, Parisa Lotfi

Bioengineering Theses - Archive

Neural implants have been used and studied for many decades. They are applied to record neural signals or to locally deliver drugs. Unfortunately, foreign body reaction and accompanied glial scar formation often lead to implant failure. The lack of knowledge about the molecular mechanism governing foreign body reactions in the brain significantly hinders the development of brain implantable devices with improved safety and biocompatibility. To study the immune responses to brain implants, a novel animal model has been developed and used for the following investigation. Our studies have established cell recruitment time courses of astrocytes, microglial cells, lymphocytes, monocytes and …

Functionalized Nanoparticles For The Selective Killing Of Cancer Cells, Paul Todd Thevenot

Bioengineering Theses - Archive

The use of nanoparticles for cancer imaging and drug delivery has produced some success in improving the efficacy and safety of cancer chemotherapy. It is generally believed that the efficiency of nanoparticle-based cancer therapy would be greatly improved if such particles could be designed to directly interact with and eradicate tumor. Many recent studies have revealed that surface functionality plays an important role in particle:cell interactions. Using titanium dioxide (TiO2) nanoparticles (21 nm diameter) as test subjects, nanoparticles with different functional groups, hydroxyl (-OH), amine (-NH2), and carboxyl (-COOH) were produced and used in this investigation. An in vitro cell …

Cytotoxic Evaluation And Factorial Analysis Of 3d Photopolymerizable Thermoresponsive Composite Nanoparticle Hydrogels For Controlled Drug Delivery In Restenosis And Wound Healing, Abhimanyu Rajaram Sabnis

Bioengineering Theses - Archive

To develop a smart drug delivery system for restenosis and wound healing applications, we investigated photopolymerizable composite nanoparticle hydrogels which can release the drug in a temperature-responsive manner. Our novel system consisting of thermoresponsive poly(N-isopropylacrylamide-co-acrylamide) (PNIPA-AAm) nanoparticles and poly(ethylene glycol) diacrylate (PEGDA) as photo cross-linker can be formed in situ in presence of ultraviolet (UV) light and Irgacure 2959 photoinitiator (PI). The main aims of this project were to investigate the system cytotoxicity and optimize drug release characteristics by performing biocompatibility and factorial analysis studies, respectively. We evaluated the cell survival of human vascular smooth muscle cells and NIH/3T3 fibroblasts …

Investigation Of Brain Activities Using Two State-Of-The-Art Diffuse Optical Imagers, Suresh Prajapati

Bioengineering Theses - Archive

Near-Infrared Spectroscopy (NIRS) and diffuse optical imaging (DOI) are increasingly used to detect hemodynamic changes in the cerebral cortex induced by brain activity. The new commercially available DOI systems CW5 and DYNOT have large number of sources and detectors; by arranging them in specific patterns, one can cover most of the adult head. This study is a preliminary step in understanding CW5 and DYNOT and exploring their capabilities for various purposes. My work is divided in to three major parts. The first goal of this study was to study changes in hemodynamic response of brain during Breath holding, using both …

Gas Permeation Through Nanoporous Polycarbonate Track- Etched Membranes: Pulsed Plasma Polymerization Of Thin Coatings To Modulate Gas Permeability, Christopher Lewis Chapman

Bioengineering Theses - Archive

Polycarbonate track-etched membranes (PCTE) of 50nm and 100nm pore size, precoated with Poly Vinyl Pyrrolidone (PVP), were surface treated with either Vinyl Acetic acid (VAA) or Perfluorohexane (C6F14) using a low duty cycle pulsed plasma polymerization technique. The effects of this surface treatment on gas permeation properties of the PCTE were addressed. Plasma coating thickness was controllably varied and resulted in gradual reduction of O2 and CO2 permeability as thickness increased from 10nm to 100nm. Plasma coating material, permeant gas, membrane pore size, and crosslink density were also varied in order to gain insight into the permeation properties of the …

Security Printing: Towards Hologram Printing, Sachin Ravindra Agate

Masters Theses

Today we are facing many situations where the genuineness of the products and documents is questioned. Counterfeiting the original products has become a business of few people, which result in the degradation of quality of products, loss of money and loss of faith of end user. To prevent such malicious act, security features are added in the final product. Security printing is one of those methods that help in preventing counterfeit products and treachery. There are many different security features, which can be added in the security printing. Apart from those features, an embossed hologram is also included in prints …

Ccfss News Fall 2007, Wei-Wen Yu Center For Cold-Formed Steel Structures

CCFSS Newsletters (1999 - 2008)

No abstract provided.

High-Resolution/High-Contrast Mri Of Human Articular Cartilage Lesions., Shadi F. Othman, Jun Li, Osama Abdullah, Jessy J. Moinnes, Richard L. Magin, Carol Muehleman

All Faculty Articles - School of Engineering and Computer Science

BACKGROUND: Magnetic resonance microscopy (MRM) is an important experimental tool in the identification of early cartilage lesions.

METHODS: Normal and degenerated cartilage samples were imaged at 11.74 T using a standard spin echo sequence. Quantitative MR measurements for T1, T2, and ADC were obtained and mapping for T2 and ADC was performed. The bi-exponential model for T2 relaxation was also explored. Histology was carried out for comparison with MR images.

RESULTS: MR images of cartilage samples displaying early stages of degeneration were positively correlated to their histological appearance in 23-microm high-resolution images and also with much shorter imaging times at …

Evaluation And Applications Of Gas Sensors, Hung Viet Cao

Electrical Engineering Theses - Archive

Gas sensors are used widely for environmental and biomedical uses. This work focuses on verifying specifications of commercial-off-the-shelf (COTS) gas sensors and their particular applications. The first chapter in this thesis gives a literature review on gas sensors, especially metal-oxide based sensors and their advantages. The second chapter focuses on evaluation of COTS NO2 sensors. The purpose is to establish a characterization method to evaluate gas sensors. I have evaluated three COTS metal-oxide based NO2 sensors and a COTS electrochemical sensor for comparison. Four different tests have been implemented to investigate the sensitivity, humidity effects, temperature effects, and selectivity for …

Design And Simulation Of An Accurate Breast Biopsy System, Sumit Tandon

Electrical Engineering Theses - Archive

Core needle biopsy is a non-invasive technique for confirming breast and prostate cancer. Over the years, several non-real time image guided systems have been developed to guide the needle to the target lesion/tumor. Frequently used methods are those employing x-ray, ultrasound, MRI or x-ray fluoroscopy to guide the needle during biopsy. However, these methods suffer from the disadvantages that they are non-real time or the imaging technique is two dimensional or ionizing. Our broad objective is to develop a visually guided, haptic assisted breast biopsy system (henceforth called ViHAB) using real time 3D ultrasound imaging and haptic guidance. The system …

System And Method For The Pooling Of Sterile Product, David A. Edelen

Industrial, Manufacturing, and Systems Engineering Dissertations - Archive

This dissertation defines an automated system and method for removing the tops from individual sealed bottles and pooling the small volumes of liquid contained in each bottle together in a collection container while maintaining the sterility of the product. This research further applied system development and process improvement methodology. More particularly, this research solved a previously unsolved problem through the unique research and development, and application of ultrasonic technology, to mitigate both product and personnel risk, and provide process improvement, as associated with the aseptic process for the pooling of sterile product.

Polymer-Based Rf Mems Devices, Jianqun Wang

Electrical Engineering Dissertations - Archive

The radio frequency micro-electro-mechanical system (RF MEMS) technology is rapidly transitioning from the research stage to commercial applications. Reducing material and fabrication costs, realizing IC compatibility, and improving the RF performance have been main focal points of many recent works. In this dissertation, we target at developing a RF MEMS methodology which realizes CMOS compatibility, cost effectiveness and high performance at the same time. The current RF MEMS devices are mostly constructed on quartz and III-V compound materials to achieve low RF losses. These approaches proved to have excellent RF performance. However these materials are expensive and unable to be …

Model Reference Adaptive Control Using Stacked Identifiers, Weider Chung

Electrical Engineering Dissertations - Archive

Model reference adaptive control is a major design method for controlling plants with uncertain parameters. The primary objective of this dissertation is to develop a new design approach for the model reference adaptive control of a single-input single-output linear time-invariant plant. The proposed method, called the "Model reference adaptive control using stacked identifiers," uses a stacked identifier structure that is new to the field of adaptive control. The goal is to make the output of the plant asymptotically track the output of the first identifier, and then driving the output of the first identifier to track that of the second …

1/F Noise In Hafnium Based High-K Gate Dielectric Mosfets And A Review Of Modeling, Siva Prasad Devireddy

Electrical Engineering Dissertations - Archive

For next generation MOSFETs, the constant field scaling rule dictates a reduction in the gate oxide thickness among other parameters. Consequently, gate leakage current becomes a serious issue with very thin SiO2 that is conventionally used as gate dielectric since it is the native oxide for Si substrate. This has driven an industry wide search for suitable alternate 'high-k' gate dielectric that has a high value of relative permittivity compared to SiO2 thereby presenting a physically thicker barrier for tunneling carriers while providing a high gate capacitance. Consequently, it is essential to study the properties of these novel materials and …

Sequences Of Near-Optimal Feedforward Neural Networks, Pramod Lakshmi Narasimha

Electrical Engineering Dissertations - Archive

In order to facilitate complexity optimization in feedforward networks, several integrated growing and pruning algorithms are developed. First, a growing scheme is reviewed which iteratively adds new hidden units to full-trained networks. Then, a non-heuristic one-pass pruning technique is reviewed, which utilizes orthogonal least squares. Based upon pruning, a one-pass approach is developed for producing the validation error versus network size curve. Then, a combined approach is devised in which grown networks are pruned. As a result, the hidden units are ordered according to their usefulness, and less useful units are eliminated. In several examples, it is shown that networks …

Making The Power Grid More Intelligent, Salman Mohagheghi, Ronald G. Harley, Ganesh K. Venayagamoorthy

Electrical and Computer Engineering Faculty Research & Creative Works

Summary form only given. This paper focuses on the applications of intelligent techniques for improving the performances of the power system controllers. Intelligent control techniques lay the foundation of the next generation of nonlinear controllers and have the advantage of further improving the controller's performance by incorporating heuristics and expert knowledge into its design. Most of these techniques are independent of any mathematical model of the power system, which proves to be a considerable advantage.

Redundancy Optimization For Clock-Free Nanowire Crossbar Architecture, Yadunandana Yellambalase, Ravi Bonam, Minsu Choi

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper a method is being proposed to find the optimal dimension of Programmable Gate Macro Block (PGMB) in clock-free nanowire crossbar architecture. A PGMB is a nanowire crossbar matrix with discrete number of rows and columns on which the NCL (Null Convention Logic) gates can be programmed. This method uses inherent redundancy to route through defective crosspoints. A 6 X 10 defect-free crossbar can be used to program any of the 27 threshold gates. Due to imperfections and variations in nanoscale manufacturing process, high defect densities are anticipated. Thus, such defects should be located when tested and the …