Engineering Commons^™

Study Of Design Tradeoffs Of Dram And Sram Memories, Using Hspice Computer Simulation, Bageshri Kale

Theses

Semiconductor random access memories are complex systems that can be described by performance parameters such as memory cycle time, access delays, storage capacity, bit packing density, chip area and retention time. In this thesis, tradeoffs between cycle time, chip area, and storage size as reflected by bit line capacitance (Cbl) were studied as a function of particular design variables: memory cell capacitance (Cc); CMOS flip-flop sense amplifier (SA) transistor sizes; and size of precharge (PC), and word line (WL) switches. Performance was optimized using circuit simulation software, HSPICE, to observe DRAM and SRAM waveforms. With TSMC 0.18 micron technology, minimum …

Simulation Analysis Of Anti-Rollover Mechanism For Vehicles, Mohib L. Raid

Theses

Rollover accidents are considered the most significant safety problems for all classes of light vehicles, especially pickups, Sport Utility Vehicles (SUV), Light Truck Vehicle (LTV) and vans. The main objective of the research is the design of a new mechanism able to keep the vehicle stable under various road conditions and high speeds, to prevent the vehicle from rolling over and to maintain the stability for the vehicle by creating an anti-rolling torque on the vehicle body capable of turning the vehicle smoothly to stable position.

Evaluation Of Effect Of Extrusion Process Variables On Mechanical Properties Of Extruded Collagen Tubes And Effect Of Post Extrusion Treatments, Mayank K. Patel

Theses

This study evaluated the effect of extrusion process variable on mechanical properties of extruded collagen tubes made using a specialized extruder, made by ZOKO Corporation of Czechoslovakia. Three extrusion variables were considered; extrusion speed, linear draw rate and rotation speed. Using Taguchi L₄ matrix, a design of experiment (DOE) was run. Two mechanical properties, wall thickness and estimated elastic modulus, were considered as response of this DOE. Data was analyzed statically to evaluate the effect of extrusion variables on both these properties. Result of this study showed that linear draw rate of the extrusion process has the highest influence …

A Kinematic Analysis Of Hand Configurations In Static And Dynamic Fingerspelling, Gillian B. Sherry

Theses

The focus of this study was the investigation of target handshapes in American Sign Language fingerspelling in order to determine whether there was a difference between static canonical structures and structures produced in the context of a movement sequence. This was achieved by measuring the joint angles of a signing hand with an 18-sensor CyberGlove® by Virtual Technologies, Inc.

A discriminant analysis was used to identify targets that occurred at points of minimum angular joint velocity. A multivariate analysis of variance with planned compansons was then applied to these dynamic data along with the static data to test the hypothesis. …

Application Of Bootstrap Resampling In Fmri, Arthika Bappal

Theses

This thesis demonstrates the use of the bootstrap resampling technique considering temporal dependency in the fMRI data to determine the reliability and confidence interval of fMRI parameters. Traditionally, the test-retest method has been used to reliably detect active voxels in the fMRI image of the brain, which is based on repetitive experimentation. The main concern with the test-retest method is the reproducibility of data over these multiple repetitions. Fatigue, habituation, motion artifacts, and repositioning errors are few of the factors, which can affect the reproducibility of data.

The conventional bootstrap resampling technique is based on the assumption that the dataset …

Supply Chain Risk Analysis, Venkata R. Kallepalli

Theses

A new decision support system is proposed and developed that will help sustaining business in a high-risk business environment. The system is developed as a web application to better integrate the supply chain entities and to provide a common platform for performing risk analysis in a supply chain. The system performs a risk analysis and calculates risk factor with each activity in the supply considering its interrelationship with other activities. Bayesian networks along with fault tree structures are embedded in the system and logical rules are used to perform a qualitative fault tree analysis, as the data required to calculate …

An Investigation Of Position And Force During Gait-Mimicking Finger Motions, Matthew Stephen Noesner

Theses

Spinal cord injuries are extremely debilitating, often leaving the injured person without the ability to use their legs (paraplegia) and sometimes, without the ability to use their arms and legs (tetraplegia or quadriplegia). Currently, primitive forms of feed-forward functional electrical stimulation (FES) and special orthotics are available for persons with paraplegia. However, these forms of FES do not allow the individual to actually control their movements on a real-time basis, nor do they offer the ability for the injured person to sense the ground on which they stand.

It is the goal of the researchers at the Neuromuscular Engineering Laboratory, …

Biomimetic Sensor For In-Vivo Applications, Daya I. Sooryadas

Theses

The development of sensitive specific devices (e.g., molecular sensors) for the detection, diagnosis and monitoring of diseases, drug discovery, environmental detection of pollutants and/or biological agents has been an active area of research. A molecular sensor is a biomolecule or biomimetic molecule that performs two distinct functions in detecting target molecules. The sensor molecule recognizes a target molecule and specifically binds to it. This specific binding generates a signal in response to the event of target binding that can be then detected. The long term vision of this thesis research work is to develop a specific recognition ligand for detecting …

Si-Sio2 Interface Behavior In N-Mosfets With Screening Potential During High-Field Injection, Purushothaman Srinivasan

Theses

This work investigates the screening of hot carrier stress degradation in n-channel MOSFETs when the devices were exposed to plasma processing. Devices with various antenna ratios were subjected to current stress (both gate injection and substrate injection) while the source and drain terminals were reverse biased by a screening potential followed by hot carrier stress. It was observed that screening of the drain edge was effective for both gate injection and substrate injection at different screening potentials. The hot carrier lifetime is directly related to interface state density (Dit), measured by charge pumping method. The results suggest that hot electron …

Particle Size Dependence On Immobilized Molecular Sensors : Assay Of Nucleic Acid Probes Attached To Paramagnetic Particles, Celin Sunny

Theses

Nanotechnology is concerned with materials and systems whose structure and components exhibit novel and significantly improved physical, chemical and biological properties, phenomena and processes due to their nano scale size.

The transition from micro scale to nano scale leads to a number of changes in physical properties, possibly including new physical principles, some of which may be yet to be discovered. One of the major factors in this is the increase in ratio of surface area to volume.

This thesis research uses the increase in ratio of surface area to volume property of going from macro to micro to nano …

Processing And Optimization Of Natural Fiber Reinforced Composites Using Date Palm Fibers, Khalifa Musabbeh Suwaidan Hamad Al-Kaabi

Theses

During the last twenty years, ecological concerns have resulted in a renewed interest in natural materials. Composite materials usually depend on using man-made fibers as the reinforcing element. The possibility of using natural fibers instead of synthetic fibers is gaining acceptance among users. This work aims to investigate the possibility of extracting natural fibers from date palm trees to be used as reinforcement with polymeric materials. The objective was achieved by characterizing fibers through different chemical, physical and mechanical tests and using different treatment methods in order to modify the fiber properties. Date Palm Fibers (DPF) exhibit a cylindrical shape …

Synthesis And Characterization Of Polyaniline And Poly (3-Methylthiophene) As Conducting Polymers, Fatma Khalifa Obaid Dalmouk

Theses

The performance of materials in general depends on their properties. There is a continuous need of new materials to meet the technological revolution that was witnessed by the end of last century. In this work, a new class of materials was synthesized. The host matrix is an Organic Conducting Polymer (OCP) of either poly(3-methylthiophene) (PMT) or poly(aniline) (PAN). The synthesis of OCP is achieved using electrochemical methods of applying constant potential or cyclic voltammetry at a platinum or graphite substrate in an acetonitrile containing tetra-alkyl-ammonium salt. The set up is three-electrode system of a platinum counter electrode and a silver/silver …

Bulk Polymerization And Structure-Property Relationship Of Medical Grade Polyurethane, Mariam Nasser Al-Saedi

Theses

Polyurethanes as biomaterials have been used in the augmentation and repair of the human body with great success. The choice of material for a particular application often hinges on the body's response to the polymer, the mechanical and thermal properties of the polymer and the stoichiometric ratio of active ingredients used in the synthesis.

A large number of polyurethanes used in medical applications are polyester-based and cannot be used in long-term implant applications because they are very susceptible to hydrolysis. Other medical-grade polyurethanes, which are suitable for implants are polyether-based which might to some extent, suffer from environmental stress cracking …

Pulsed Laser Ablation Deposition And Optical Characterization Of Hexagonal-Wurtzite Silicon, Berzelius Ybanez Cada

Theses

Hexagonal-wurtzite silicon phase silicon is an unusual polymorph of silicon with potentially useful electro-optical properties. Previous studies using a simple deposition system demonstrated that laser ablation of the standard cubic-diamond silicon produces droplets containing hexagonal-wurtzite crystallites. In order to study the process parameters and to deposit larger hexagonal crystals, a new pulsed laser ablation system with variable parameters was assembled and tested. Deposition expenments were performed in high vacuum with different laser pulse power. Raman spectroscopy showed that the new system successfully produces hexagonal-wurtzite silicon. The droplet size distributions, measured with an optical microscope, were found to depend on the …

Combustion Of Aerosolized Spherical Aluminum Powders And Flakes In Air, Binu Zacharia Eapen

Theses

Combustion rates and completeness of aerosolized spherical aluminum powders and flakes are compared using constant volume explosion experiments. The comparison of particles and flake sizes was made based on their specific surface areas determined using the Brunauer-Emmett-Teller (BET) method and respective "BET diameters". It is observed that the rates of pressure rise and rates of flame propagation were higher for aluminum powders with BET diameters of about 2 to 5 μm compared to aluminum flakes for which the BET diameters were under 1 μm In agreement with the flame propagation rates, the overall completeness of combustion was also higher for …

A Labview Program To Obtain The Initiating Component Of A Vergence Eye Movement In An Open-Loop Experiment, Anuj P. Daftari

Theses

The vergence oculomotor system is used in viewing objects moving in depth, such as when a baseball player tracks a ball moving towards him. It is composed of two components according to the Dual Mode Theory; a fast preprogrammed initiating component and a slow feedback-controlled sustaining component. The initiating component is described with open-loop control and the sustaining component is described as a closed-loop feedback control system. Previously, several languages have been utilized to develop programs to study and isolate the open-loop portion of vergence eye movements. Presenting a subject with a stimulus, which initiates an open-loop response has been …

Configurable Computer Systems Can Support Dataflow Computing, Anish Arvind Sathe

Theses

This work presents a practical implementation of a uni-processor system design. This design, named D²-CPU, satisfies the pure data-driven paradigm, which is a radical alternative to the conventional von Neumann paradigm and exploits the instruction-level parallelism to its full extent. The D²-CPU uses the natural flow of the program, dataflow, by minimizing redundant instructions like fetch, store, and write back. This leads to a design with the better performance, lower power consumption and efficient use of the on-chip resources. This extraordinary performance is the result of a simple, pipelined and superscalar architecture with a very …

Evaluation Of Postural Stability Using Sensory Organization Test, Tiffany Sims

Theses

Poor postural stability of the elderly and other patients has been a major concern.The cost of treating injuries due to poor stability is expected to rise to $32.4 Billion by 2020. Many interventions have been proposed and used to improve stability. In order to determine the efficacy of these interventions, an objective evaluation of postural stability before and after intervention is important.

The aim of this thesis was to scientifically analyze the ambiguities in the equilibrium score (ES) given by the Neurocom Smart Equitest (NSE) machine, and compare it to a new measure of stability that has been proposed by …

Magneto-Rheological Fluid Orthosis For Suppressing Tremor, Hyoung-Joo Yeo

Theses

Tremor is a common movement disorder that occurs with specific neurological conditions. This condition may seriously impact daily living activities. The aim of the present study is to evaluate the possibility of the development of a wearable technology that is capable of exerting torques at a user's joints for suppressing tremor.

This thesis is based on the concept of "smart structures" which are made of Magneto-Rheological (MR) fluid that can dynamically alter its viscosity under magnetic field. The wearable tremor suppressing orthosis needs several conditions. It should be safe, light weight, simple and small in structure, and easily attachable. An …

Chemical Vapor Deposition Of Polymeric Films, Chi Yu

Theses

Poly-peri-naphthalene (PPN) is a one-dimensional (1 -D) graphite polymer with unique planar ladder-like conjugated molecular structure. PPN was predicted to be a good intrinsic conductor and have high thermal stability and high environmental stability.

In this project, chemical vapor deposition (CVD) and plasma enhanced chemical vapor deposition (PECVD) of carbon films with PPN structure using PTCDA as precursor were carried out under different conditions. There is only limited information in literature on the synthesis of PPN films by PECVD process, which may allow deposition at a higher rate with lower substrate temperature. In this work the influence of deposition parameters, …

Kinetics Of Ho2 Abstraction Of H Atoms From Hydrocarbons And Thermochemical Properties Of Urethane Monomers And Radicals, Rajul Shah

Theses

SECTION I: Kinetics of HO₂ Abstraction of H Atoms From Hydrocarbons

Structures, internal rotational barriers and ideal gas thermochemical properties, ΔH^°_f98 for representative series of transition states for abstraction of H atoms from primary, secondary and tertiary hydrocarbons by the HO₂ radical, TC-HOOH (1), TCC-HOOH (2), TC₂C-HOOH (3), TC₃C-HOOH (4), TC₂CC-HOOH (5), TC₂CC-HOOHC (6) and TC₃CCC-HOOH (7) are analyzed in this study. Molecular structures and vibrational frequencies are determined at the B3LYP/6-3111G(d,p) density functional level. The S°₂₉₈ and C_p(T) values (300≤T/K≤1500) from vibrational, …

Development Of Fmri Compatible Lower Body Negative Pressure System, Pratap Singh Kunwar

Theses

The lower body negative pressure (LBNP) system provides a controlled, measured orthostatic stress to the cardiovascular system, which can be used with a magnetic resonance imaging (MRI) machine to study cardiovascular and cerebrovascular responses to graded LBNP. In the past, even though functional MRI (fMRI) was considered as one of the best modalities with which to measure small metabolic changes in the brain, it has not been used with an LBNP system to measure cerebrovascular changes. This was due to the lack of an fMRI compatible LBNP system.

In this project, an tMRI compatible LBNP system was first constructed without …

Characterization Of Aluminum Powder Ignition, Salil Mohan

Theses

Heating rate effect and particle size effect on ignition temperature of Al powder were studied to collect data for development of a possible Al powder ignition model. Aluminum ignition is associated with a highly accelerated burn rate and high combustion enthalpy. A new ignition model, which can adequately interpret these conditions, is needed to develop better propulsion fuels, explosives and incendiaries that use Al as an additive. This experimental program was focused on preparing framework for characterization of ignition kinetics of Al powder by determining the ignition temperature for different, systematically varied, heating rates and particle size. The experimental setup …

Transmission Of Light And Audible Sound In A Synthetic Fog Medium, Bhavin Babaria

Theses

The primary goal of the thesis was to study the propagation of visible light and auditory sound through a synthetic fog medium compared to an ambient air environment. It is known that the fog substantially decreases the visibility however; this has not been studied quantitatively. Further information regarding other energies such as sound is also needed to understand how the energy reacts in the fog medium. The extent of visual and auditory degradation in humans needs to be investigated. Researchers have studied light transmitted through water, air; however, no one has studied how light or sound is transmitted through a …

Simultaneous Heat And Mass Transfer To A Liquid Through Two Separated Interfaces, Ku-Il Park

Theses

The oxygenator is the main element of a heart-lung machine, which takes over the work of the lungs (adding oxygen to and removing carbon dioxide from the blood) during an operation. Oxygenators function by passing oxygen through a hollow fiber (straw-like fiber), where blood gases are exchanged via tiny pores in the fiber walls. In this study, a fiber-in-fiber technology was used to design a temperature controlled blood oxygenator membrane module. A Celgard® X-10 hollow fiber was put through the lumen of a polypropylene hollow fiber having a solid wall. Both fibers are made of polypropylene and are waterproof due …

Wavelet Transform Methods For Identifying Onset Of Semg Activity, Janina Wilen

Theses

Quantifying improvements in motor control is predicated on the accurate identification of the onset of surface electromyograpic (sEMG) activity. Applying methods from wavelet theory developed in the past decade to digitized signals, a robust algorithm has been designed for use with sEMG collected during reaching tasks executed with the less-affected arm of stroke patients. The method applied both Discretized Continuous Wavelet Transforms (CWT) and Discrete Wavelet Transforms (DWT) for event detection and no-lag filtering, respectively. Input parameters were extracted from the assessed signals.

The onset times found in the sEMG signals using the wavelet method were compared with physiological instants …

Modeling And Analysis Of Hospital Facility Layout Problem, Amol Shrikrishna Padgaonkar

Theses

The optimal solution to any facility layout problem is an important aspect and a major concem as it involves significant material handling and transportation cost. The objective is to arrange the departments within the predefined facility boundaries in the way that the interaction between the functions is efficient and the overall movement cost is minimized. While facility layout problems have traditionally focused on manufacturing facilities, there has been little work on analyzing layouts for hospitals. The thesis focuses on hospital facility layout problems (HLP) to (i) minimize the movements of patients and (ii) minimize the movements of accompanying resources such …

Investigation Of Heart Rate Variability During Sleep Apnea, Sekar Subramanian

Theses

Sleep apnea is a disorder, where there are repetitive pauses in respiratory flow of at least 10 seconds or longer duration, and which occur more than five times per hour. Apnea has strong modulating effects on the autonomic nervous system, with prominent heart rate variation. It can be assumed that during sleep, internal influences (sympathetic and parasympathetic nervous system activities) dominate the autonomic nervous system; in addition repetitive apneas are accompanied by a pronounced increase in average heart rate. The aim of this study was to investigate the heart rate variability using spectral analysis and time-frequency analysis during sleep apnea. …

Adaptive Turn-Prohibition Routing Algorithm For The Networks Of Workstations, Amey Bhaskar Shevtekar

Theses

Deadlock occurrence is a critical problem for any computer network. Various solutions have been proposed over last two decades to solve problem of deadlocks in networks using different routing schemes, like up/down routing algorithm used in Myrinet switches. However, most of existing approaches for deadlock-free routing either try to eliminate any possibility of deadlock occurrence, which can result in putting extra restrictions on the routing in the networks or put no restrictions on routing, which leads to other approach namely deadlock recovery. In this thesis emphasis is on developing hybrid approach for routing in wormhole networks, wherein some prohibition is …

Development Of A Low Jitter Multiplying Delay Locked Loop, Ian Kennedy

Theses

The clock generator is a critical component in high-speed wireline communication systems. The clocks in these systems mark time at precise regular intervals. Any deviation of the clock edges from these ideal time points is called jitter and it degrades the overall integrity of the communication system. This thesis looks at both phase locked loops (PLLs) and delay locked loops (DLLs) and their ability to provide these precise clocks. Expressions for the thermal noise-induced jitter in both the PLL and DLL are compared. From this, the DLL is shown to possess the potential for better jitter performance. However, to realise …