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LSU Master's Theses

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Full-Text Articles in Engineering

Heuristics For Memory Access Optimization In Embedded Processors, Saravanan Subramanian Jan 2005

Heuristics For Memory Access Optimization In Embedded Processors, Saravanan Subramanian

LSU Master's Theses

Digital signal processors (DSPs) such as the Motorola 56k are equipped with two memory banks that are accessible in parallel in order to offer high memory bandwidth, which is required for high-performance applications. In order to make efficient use of the memory bandwidth offered by two or more memory banks, compilers for such DSPs should be capable of appropriately partitioning the program variables between the two memory banks and scheduling accesses. If two variables can be accessed simultaneously, then it is essential to have these two variables assigned to two different memory banks. Also if these two variables are in …

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Cryopreservation Of Reproductive Cells And Tissues, Guanglei Li Jan 2005

Cryopreservation Of Reproductive Cells And Tissues, Guanglei Li

LSU Master's Theses

Cryopreservation of reproductive cells and tissues is a useful technique to deliver intact genomes, maximize the distribution of favorable genes, control disease spread. It is widely applied to many fields such as biology, medicine, ecology and agriculture. To optimize the cryopreservation procedure, the biophysical responses of reproductive tissues at different cooling conditions and in different mediums must be clearly understood. Here we studied the biophysical response during freezing of: 1) bovine sperm frozen at a cooling rate of 20 ˚C/min in three media: without cryopreservation agents(CPAs), with 0.7 M glycerol, and with 0.7 M glycerol along with 1.5 mg/ml of …

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Usability Of Home Cholesterol Test Kits And Their Impact On Patients' Decision, Deepti Surabattula Jan 2005

Usability Of Home Cholesterol Test Kits And Their Impact On Patients' Decision, Deepti Surabattula

LSU Master's Theses

Release of home health testing kits into the market has enabled people to take care of their own health. Misinterpretation of results and delays in treatments are the major concerns of the doctors. In the present study, two cholesterol test kits, AccuchekÒ Instant plusÒ and Home Access® Instant Cholesterol Test, were compared on the basis of user performance, accuracy, and the patient’s future medical decisions based on the test results. The study was conducted with 30 participants, 15 men and 15 women. Participants tested their overall cholesterol level with both kits. In addition, a clinical cholesterol evaluation, the medical gold …

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Study Of The Effects Of Magnetic Field On The Properties Of Combustion Synthesized Iron Oxide Nanoparticles, Nagaraju Komuravelli Jan 2005

Study Of The Effects Of Magnetic Field On The Properties Of Combustion Synthesized Iron Oxide Nanoparticles, Nagaraju Komuravelli

LSU Master's Theses

Nanosized chain-like aggregates were developed in an iron pentacarbonyl-carbon monoxide (Fe(CO) 5 ¨C CO) air diffusion flame system. Magnetic field was applied around the diffusion flame using an electromagnet with an intensity of 0.4 Tesla. Transmission Electron Microscopy (TEM) analysis was performed to observe the behavior of the chains formed and to study the effect of magnetic field on these chains. These chain aggregates consist mainly of Fe2O3, which play a vital role in magnetic storage devices. Diffraction pattern analysis and X-ray Photon Spectroscopy (XPS) were carried out to confirm that the chain aggregates consist of mainly ¦Ã-Fe2O3. The effect …

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Functionalization Of Gold And Glass Surfaces With Magnetic Nanoparticles Using Biomolecular Interactions, Bala Sesha Giri Rao Nidumolu Jan 2005

Functionalization Of Gold And Glass Surfaces With Magnetic Nanoparticles Using Biomolecular Interactions, Bala Sesha Giri Rao Nidumolu

LSU Master's Theses

Advances in nanotechnology have enabled the production and characterization of magnetic particles with nanometer-sized features that can be functionalized with biological recognition elements for clinical and biosensing applications. In the present study the synthesis and interactions between self assembled monolayers (SAMs) and functionalized nanoparticles have been characterized. Size and shape of magnetic nanoparticles synthesized wet chemically starting from ferrous and ferric salts were verified by transmission electron microscopy (TEM). These nanoparticles were then conjugated with FITC-labeled streptavidin through carbodiimide (EDC) chemistry. SAMs of thiol-capped biotins were synthesized on gold surfaces for capture of the conjugated nanoparticles. Characterization of nanoparticle functionalization …

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Assessing The Needs For Intermediate Diaphragms In Prestressed Concrete Girder Bridges, Anand Kumar Chandolu Jan 2005

Assessing The Needs For Intermediate Diaphragms In Prestressed Concrete Girder Bridges, Anand Kumar Chandolu

LSU Master's Theses

Reinforced concrete Intermediate Diaphragms (IDs) are still being used in prestressed concrete (PC) girder bridges in Louisiana. Some of the advantages of providing IDs are disputed and also use of IDs increases the cost and time of construction. There is no consistency in the practice of providing IDs among various states and codes of practice and overall there is a lack of clarity on the effectiveness of IDs and their needs in prestressed concrete bridges. The objectives of this research are to assess the need of reinforced concrete (RC) IDs in PC girder bridges and to determine their effectiveness and …

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Factors Effecting Field Emission From Multiwalled Carbon Nanotubes, Abhilash Krishna Jan 2005

Factors Effecting Field Emission From Multiwalled Carbon Nanotubes, Abhilash Krishna

LSU Master's Theses

Carbon nanotubes (CNT) have emerged to be one of the most versatile of materials ever discovered. The small dimensions, high electrical conductivity and strength along with other physical and electrical properties make them a unique material with a wide range of promising applications. One such use is that of CNTs as electron beam sources. A typical CNT has a diameter of only a few nanometers but can be hundreds of microns long. Applying a voltage across the length of such an object results in field emission of electrons from one end of the tube. This effect is due to intense …

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Blind Multiridge Detection And Reconstruction Using Ultrasonic Signals, Rekha Katragadda Jan 2005

Blind Multiridge Detection And Reconstruction Using Ultrasonic Signals, Rekha Katragadda

LSU Master's Theses

Time-frequency signal analysis has been widely applied in the modern radar, acoustic, sonar and ultrasonic signal processing techniques. Recently, the nondestructive testing (NDT) techniques via the ultrasonic instrumentation have shown the striking capability of the quality control for the material fabrication industry. In this thesis, we first provide a general mathematical model for the ultrasonic signals collected by pulse-echo sensors and then design a totally blind, novel, signal processing NDT technique relying on neither a priori signal information nor any manual effort. The signature signal can be blindly extracted by using the automatic optimal frame size selection for further modeling …

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Damage Mechanics Of Composite Materials Using Fabric Tensors, Ziad N. Taqieddin Jan 2005

Damage Mechanics Of Composite Materials Using Fabric Tensors, Ziad N. Taqieddin

LSU Master's Theses

The major objective of this work is to relate continuum damage mechanics introduced through the concept of fabric tensors to composite materials within the framework of classical elasticity theory. A model of directional data-damage mechanics for composite materials is formulated using fabric tensors. In addition, a general hypothesis for damage mechanics is postulated. It is seen that the two available hypotheses of elastic strain equivalence and elastic energy equivalence may be obtained as special cases of the postulated general hypothesis. This general hypothesis is then used to derive the sought relationship between the damage tensor for composite materials and the …

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Modeling The Fate And Transport Of Chlorinated Benzenes In Baton Rouge Bayou, Sudheer Nimmagadda Jan 2005

Modeling The Fate And Transport Of Chlorinated Benzenes In Baton Rouge Bayou, Sudheer Nimmagadda

LSU Master's Theses

Knowledge of the fate and transport of chlorinated benzenes is necessary at certain sites for effective remediation of contaminated soils using plants. Current research is examining the capability of wetland plants to catalyze degradation or attenuate migration, but again requires knowledge of the uptake of contaminants from an aqueous environment. A two stage model was used to estimate the rate of uptake of contaminants from sediments. The first stage of the model predicts pollutant leaching rates from sediments to the overlying water, which would then be fed into the plant or bioreactor model systems. In this study the flux from …

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The Electrodeposition And Property Study Of Nickel-Rhenium Alloy, Shirong Wen Jan 2005

The Electrodeposition And Property Study Of Nickel-Rhenium Alloy, Shirong Wen

LSU Master's Theses

The electrodeposition of nickel-rhenium alloys from Ni(II) and Re(VII) solution was studies in an aqueous acidic solution. Different plating current density and pH have been carried out, and the effect of them on the composition of the deposited Ni-Re alloy was studied. Wavelength-dispersive spectrometer (WDS) was used to measure the composition of Ni-Re alloy. The thermal stability of nickel-rhenium alloy system has been investigated. Differential scanning calorimetry (DSC) tests have been conducted for the electroplated Ni-Re samples in order to find the possible heating initiated interactions at elevated temperatures. To investigate the thermal stability of Ni-Re alloys, the samples were …

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Assimilation And Removal Of Phosphorus Within The Marshland Upwelling System, Derek A. Evans Jan 2005

Assimilation And Removal Of Phosphorus Within The Marshland Upwelling System, Derek A. Evans

LSU Master's Theses

The marshland upwelling system (MUS) is an alternative onsite wastewater system that was developed to treat domestic wastewater derived from coastal communities. Previous studies have researched the systems ability to treat fecal coliforms and nitrogen. The objectives of this research were to (1) assess the treatment efficiency of the MUS for removing both total phosphorus and orthophosphate, (2) provide preliminary design and operational guidelines for phosphorus removal, and (3) develop a parameter to project longevity of the MUS for treating phosphorus. Performance efficiency was compared for a system which operated for 23 months located in Bayou Segnette State Park and …

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Zeolite And Metal Oxide Catalysts For The Production Of Dimethyl Sulfide And Methanethiol, Craig Plaisance Jan 2005

Zeolite And Metal Oxide Catalysts For The Production Of Dimethyl Sulfide And Methanethiol, Craig Plaisance

LSU Master's Theses

Metal oxide and zeolite catalysts were examined to determine their suitability for the production of methanethiol and dimethyl sulfide from the condensation of methanol and hydrogen sulfide. Fixed bed reactor experiments were used to test the catalysts in these processes. The acid sites of these catalysts were characterized by investigating the thermal desorption of 1-propanamine from these sites. It was found that WO3/ZrO2, La2O3/Al2O3, g-Al2O3, and HZSM-5 catalysts were active and selective in the production of dimethyl sulfide. On these four catalysts, the reaction converting methanol to dimethyl ether and the methanethiol disproportionation reaction were fast and close to equilibrium. …

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A Robust Noise Spectral Estimation Algorithm For Speech Enhancement In Voice Devices, Brett Joseph Chessher Jan 2005

A Robust Noise Spectral Estimation Algorithm For Speech Enhancement In Voice Devices, Brett Joseph Chessher

LSU Master's Theses

In this thesis, a new robust noise spectral estimation algorithm is proposed for the purpose of single-microphone speech enhancement. This algorithm can generate the optimal noise spectral estimates in the Minimum Mean Square Error (MMSE) sense based on the speech statistics in the noisy environments. Compared to the well-adopted conventional noise spectral estimation method using the single-pole recursion, our proposed scheme is more reliable since the recursion coefficients are adaptable and optimal in the MMSE therein. We also propose a new accurate Resulting Signal-to-Noise Ratio (R-SNR) estimator as a quality measure to benchmark the existing noise spectral estimation techniques. This …

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Modeling Destination Choice In Hurricane Evacuation With An Intervening Opportunity Model, Bin Chen Jan 2005

Modeling Destination Choice In Hurricane Evacuation With An Intervening Opportunity Model, Bin Chen

LSU Master's Theses

In this study, a trip distribution model for hurricane evacuation using the intervening opportunity method was developed. Post Hurricane Floyd survey data was used for model calibration and comparison. To model the behavior that people tend to evacuate away from the path of the hurricane, a new concept of equal destination attractiveness was introduced and an extended intervening opportunity model was built on this basis and implemented in TransCAD. The gravity model, intervening opportunity model and its extended version were compared using several statistical measures. This study demonstrates that it is possible to use the intervening opportunity theory to model …

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Mesoscopic Simulation Of Grain Boundary Diffusion Creep In Inhomogeneous Microstructures, Kanishk Rastogi Jan 2005

Mesoscopic Simulation Of Grain Boundary Diffusion Creep In Inhomogeneous Microstructures, Kanishk Rastogi

LSU Master's Theses

At high temperatures, stresses well below the material’s tensile yield strength can induce permanent deformation over a period of time. This time-dependent progressive deformation of a material at constant stress is called Creep and is observed in both crystalline and non-crystalline solids. The principal deformation processes contributing to creep deformation are slip, sub-grain formation and grain-boundary sliding. Mechanisms involving creep of crystalline materials involve either dislocation motion or diffusional flow of atoms or both. Extensive studies have been done to ascertain the creep mechanism in various regimes of temperature and applied stresses. At low stresses and high temperatures, grain boundary …

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Enhanced Gas Recovery Using Pressure And Displacement Management, Thomas Walker Jan 2005

Enhanced Gas Recovery Using Pressure And Displacement Management, Thomas Walker

LSU Master's Theses

The work contained in this thesis combines two previous enhanced gas recovery techniques; coproduction of water and gas from water-drive reservoirs and waterflooding of low pressure gas reservoirs. These two techniques allow the control of reservoir pressure and sweep efficiency through planed production or injection of water. A recovery optimization method, which is applicable to any gas reservoir, was developed using the concept of pressure and displacement management (PDM). Two simulation studies were conducted, using Eclipse©, to investigate recovery optimization by coproduction and waterflooding. From the coproduction study it was determined that the water production rate needed to optimize recovery …

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Pressure-Velocity Correlation Study On 1:50 Scale Model Of The Ttu Wind Engineering Research Field Lab Building, Praveen Kumar Jan 2005

Pressure-Velocity Correlation Study On 1:50 Scale Model Of The Ttu Wind Engineering Research Field Lab Building, Praveen Kumar

LSU Master's Theses

The goal of the present study is to investigate the relationship between incident wind velocity fluctuations and the surface pressure fluctuations on the roof of a low rise building. The goal was fulfilled by studying the pressure velocity correlation on 1:50 scale model of a typical low rise building, the Wind Engineering Research Field Laboratory (WERFL) building located at Texas Tech University, Lubbock. The experimental study was carried out in the LSU Wind Tunnel Laboratory by simulating the boundary layer prevalent at the full-scale site. The velocity profile in the boundary layer was measured using the TSI Hot-Wire system with …

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High-Freequency Cmos Vlsi Chip Testability And On-Chip Interconnect Modeling, Evan Ross Shultz Jan 2005

High-Freequency Cmos Vlsi Chip Testability And On-Chip Interconnect Modeling, Evan Ross Shultz

LSU Master's Theses

As high-speed digital and radio-frequency mixed-signal integrated circuits become increasingly common in product designs in industry, it is important for VLSI designers to be familiar with the challenges of chip testing and the behavior of circuit elements, including on-chip interconnect, at high frequencies. Expensive, specialized test equipment and software simulation packages for high-frequency chip testing and design are not always accessible for student research. This thesis documents the setup and characterization of a best-possible environment for high-frequency chip testing and data acquisition using existing laboratory equipment and resources. Experimental methodologies and measurement results of on-chip interconnect signal integrity and delay, …

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Performance Of Disc Brushless Dc Motor Applied As Gearless Drive For Wheelchair, Deepti Rao Chikkam Jan 2005

Performance Of Disc Brushless Dc Motor Applied As Gearless Drive For Wheelchair, Deepti Rao Chikkam

LSU Master's Theses

The currently used electric drive for a wheelchair consists of brush permanent magnet DC motor and mechanical transmission that drives the wheels. The overall efficiency of this kind of drive usually does not exceed 60%. At present there is under study much more effective drive that consists of brushless DC motor which embedded into the wheel rim directly drives the wheelchair. This type of high efficiency gearless drive is the object of this thesis project. The particular brushless DC motor is a torus - type motor with a high energy rare - earth magnets and ferromagnetic teeth that fill in …

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Power Supply Current [Ips] Based Testing Of Cmos Amplifier Circuit With And Without Floating Gate Input Transistors, Vanikumari Pulendra Jan 2005

Power Supply Current [Ips] Based Testing Of Cmos Amplifier Circuit With And Without Floating Gate Input Transistors, Vanikumari Pulendra

LSU Master's Theses

This work presents a case study, which attempts to improve the fault diagnosis and testability of the power supply current based testing methodology applied to a typical two-stage CMOS operational amplifier and is extended to operational amplifier with floating gate input transistors*. The proposed test method takes the advantage of good fault coverage through the use of a simple power supply current measurement based test technique, which only needs an ac input stimulus at the input and no additional circuitry. The faults simulating possible manufacturing defects have been introduced using the fault injection transistors. In the present work, variations of …

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Graphical Pilot Interface Simulator (Gpis), Jeffry Jorge Handal Jan 2005

Graphical Pilot Interface Simulator (Gpis), Jeffry Jorge Handal

LSU Master's Theses

The thesis develops a graphic interface for a dynamic system simulation implemented in the SIMULINK environment. The dynamic system is a B747-200 modeled as a rigid body with six degrees of freedom. The equations and database of aerodynamic coefficients over the complete flight envelope were provided by NASA’s Langley Research Center for the research project “Aircraft Safety: Managing Control Upsets.” The purpose of the interface is to allow the user to “fly the plane from the keyboard;” i.e., interact with the simulation by manipulating, from the keyboard, the main control surfaces and engine thrust and observing the performance of the …

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Analysis Of Performance Of Single-Phase Reluctance Linear Motor, Subhadra Devi Ganti Jan 2005

Analysis Of Performance Of Single-Phase Reluctance Linear Motor, Subhadra Devi Ganti

LSU Master's Theses

The design and principle of operation, as well as the electromechanical phenomena of a single-phase linear reluctance motor are discussed. The motor with transverse magnetic flux consists of a primary part, which is moving and a secondary part which is stationary and does not have any windings. The motor can operate under AC or DC supply. When supplied from an AC source it must be equipped with a capacitor connected in series with the coil. In this case the motor operates on the basis of resonance in an RLC primary circuit. When supplied from a DC source it must be …

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Modeling Destination Choice And Measuring The Transferability Of Hurricane Evacuation Patterns, Naveen Kumar Modali Jan 2005

Modeling Destination Choice And Measuring The Transferability Of Hurricane Evacuation Patterns, Naveen Kumar Modali

LSU Master's Theses

In this study a gravity model was used to model destination choice during a hurricane evacuation. Hurricane Floyd data was used to calibrate and apply the gravity model. Two different models were generated for different destination types; home of friends/relative and hotels and motels are the two different destination types for which the models were generated. The performance of the gravity model was tested by comparing the observed and estimated OD matrices using the chi-squared test. The results have indicated that gravity model developed in this study can successfully reproduce the observed trip destinations during a hurricane evacuation The Floyd …

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Physical Model Experiments Of The Gas-Assisted Gravity Drainage Process, Amit P. Sharma Jan 2005

Physical Model Experiments Of The Gas-Assisted Gravity Drainage Process, Amit P. Sharma

LSU Master's Theses

The displacement of oil by gas injection in oil reservoirs is an attractive method of improved oil recovery. Commercial gravity-stable gas injection projects have demonstrated excellent recoveries; however, their application has been limited to dipping reservoirs and pinnacle reefs. Horizontal gas floods and the water alternating gas (WAG) processes, practiced in horizontal type reservoirs, have yielded less than satisfactory recoveries of 5-10%. The Gas Assisted Gravity Drainage (GAGD) Process being developed at LSU extends the concept of gravity-stable gas floods to horizontal type reservoirs to improve volumetric sweep and oil recovery. This experimental study consists of a series of visual …

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Superposition Coding Based Co-Operative Diversity Schemes, Anil Kumar Goparaju Jan 2005

Superposition Coding Based Co-Operative Diversity Schemes, Anil Kumar Goparaju

LSU Master's Theses

With a prefixed decoding order at receiver end, superposition coding approach intended for degraded broadcast channels was proposed to improve the average throughput in a point-to-point wireless channel. In this thesis, we first rigorously show the optimal decoding strategy when two Gaussian codebooks are superposed together to send source information to its receiver. Our results rigorously prove the optimality of performing successive interference cancellation at receiver end. Decoding failure at relays imposes a bottle neck to improving overall throughput in relay channels with decode-and-forward relaying strategy. We then extend this framework for a single link to relay channels to optimize …

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Analysis Of Alternative Well Control Methods For Dual Density Deepwater Drilling, Mikolaj Stanislawek Jan 2005

Analysis Of Alternative Well Control Methods For Dual Density Deepwater Drilling, Mikolaj Stanislawek

LSU Master's Theses

The recent push into deepwater is currently limited by high drilling costs resulting from conventional well designs. As a result, dual gradient drilling methods have been proposed. This research investigates riser gas-lift as a potential means to implement a dual gradient system. A primary concern is well control in a system containing so many different density fluids and different flow paths. The specific concerns addressed in this study were kick detection, cessation of formation feed-in, removal of kick fluids, and re-establishing hydrostatic control with a constant bottom hole pressure method. These concerns were studied using a transient, multiphase simulator whose …

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Comparative Analysis Of Conventional And Ici-Self-Cancellation Digital Video Broadcasting Transceivers, Khaled Z. Matarneh Jan 2005

Comparative Analysis Of Conventional And Ici-Self-Cancellation Digital Video Broadcasting Transceivers, Khaled Z. Matarneh

LSU Master's Theses

Digital video broadcasting–terrestrial (DVB-T) is one of the important technologies in the communication area because of its capability of high data-rate multimedia transmission. Orthogonal frequency division multiplexing (OFDM) has been the backbone technique in the current DVB-T systems adopted by Europe and Japan. However, since the OFDM system is very sensitive to the frequency synchronization and phase errors, which will induce the intercarrier interference (ICI), the ongoing research has been dedicated to this ICI problem in the presence of the Doppler frequency drift and the fading channels. A means to deal with the ICI problem is called the ICI self-cancellation …

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An Evaluation Of Ansys Contact Elements, Serhan Sezer Jan 2005

An Evaluation Of Ansys Contact Elements, Serhan Sezer

LSU Master's Theses

The ANSYS code offers stress analysts a variety of contact element options: point-to-surface or surface-to-surface and low-order or high-order elements, in concert with any one of five contact algorithms (augmented Lagrangian, penalty method, etc.). This raises questions as to what option performs best under what circumstances. Here we offer some answers to these questions by examining performance in some numerical experiments. The numerical experiments focus on frictionless contact with a rigid indenter; even so, the number of experiments involved is quite large. The experiments use a battery of test problems with known analytical solutions: contact patch tests with nodes matching …

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Ternary Logic To Binary Bit Conversion Using Multiple Input Floating Gate Mosfets In 0.5 Micron N-Well Cmos Technology, Sowmya Subramanian Jan 2005

Ternary Logic To Binary Bit Conversion Using Multiple Input Floating Gate Mosfets In 0.5 Micron N-Well Cmos Technology, Sowmya Subramanian

LSU Master's Theses

In the present work, a CMOS ternary to binary bit conversion technique has been proposed using multiple input floating gate MOSFETs. The proposed circuit has been implemented in 0.5 µm n-well CMOS technology. The ternary input signals of {-1, 0, +1} are represented as -3 V, 0 V and +3 V, respectively. The ternary input is given as a combination of any two of the three voltage levels and the 4-bit binary output is generated in which the left most bit is sign bit (SB) followed by most significant bit (MSB), second significant bit (SSB) and the least significant bit …

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