Engineering Commons^™

Effect Of Overhead Drilling Support On Muscular Activity Of Shoulder, Bharat Kumar Bhogaraju Bhallam Venkata

LSU Master's Theses

This study examines the effect of an overhead drilling support and position of the arm on muscular activity of the shoulder. Five male participants simulated an overhead drilling task by using a drill in near, middle and far reach positions. Electromyographic measurements were taken from the dominant side anterior deltoid, bicep and trapezius muscles. Root mean square amplitude (RMS) of the EMG activity from these muscles was used to determine the load on the muscular system. The participants used a subjective rating scale to evaluate the overhead support stand and holding position. The results demonstrate that the overhead support stand …

Simulations Of A Modified Micro-Scale Electrophoretron, Nada Elmajdoub

LSU Master's Theses

This paper presents theoretical analysis and numerical simulations of a modified micro-scale electrophoretron adapted for cycling reaction applications (PCR, LDR...). The electrophoretron consists of a closed-loop microchannel. If one part of the length of the channel has an electroosmotic mobility of an opposite sign than the remaining part, a continuous cyclic motion of the fluid can be sustained if a potential difference is applied on two electrodes strategically placed along the channel. Conservation of mass leads to the formation of a pressure gradient and a related hydrodynamic flow. Under appropriate combination of design parameters, the combined Electroosmotic -hydrodynamic flow contributes …

Comparative Study Of Axial Flux Permanent Magnet Brushless Dc Motor Operating With The Winding Connected In Single-Phase And Two-Phase System, Sunil Kumar Challa

LSU Master's Theses

The object of the study is a double-sided axial flux permanent magnet brushless dc (AFPM BLDC) motor with salient pole stator. Its winding can be connected either in single-phase or in two-phase system, which results in different operation of the motor.

The objective of the thesis is to analyze and compare the performances of the AFPM BLDC motor with single-phase winding and two-phase winding. To study the motor operation, a mathematical dynamic model has been proposed for each of the motor with different winding, which became the basis for simulations that were performed using MATLAB/SIMULINK software package.

The calculations were …

Space-Time Block Coding For Multiple Transmit Antennas Over Time-Selective Fading Channels, Ioannis Erotokritou

LSU Master's Theses

The last decade we have witnessed an extraordinary growing interest in the field of wireless communications. Wireless industry has recently turned into a technology known as Multiple-Input Multiple-Output (MIMO) to minimize errors and optimize data speed. This is done by using multiple transmit and receive antennas, as well as appropriate space-time block code techniques. Due the fact that time-selective fading channels exist, the assumption that the channel is being static over the length of the codeword does not apply in this thesis. The channel state varies over the number of signal intervals, and in such case the orthogonality of the …

Distribution Dynamics Of Complex Systems, Young-Pyo Jeon

LSU Doctoral Dissertations

A complex system is defined as a system with many interdependent parts having emergent self-organization; analyzing and designing such complex systems is a new challenge. A common observable structure of many complex systems is the network, which is connections among nodes, and thus inherently difficult to describe. The goal of this research is to introduce an effective methodology to describe complex systems, and thus we will construct a population balance (distribution kinetics) model based on the association-dissociation process to describe the evolution of complex systems. Networks are commonly observed structures in complex systems with interdependent parts that self-organize. How networks …

Overview Of Cogeneration At Lsu, Robert,Jr. Buckley

LSU Master's Theses

Cogeneration (or Combined Heat and Power) continues to gain importance in power production because of its high efficiency, environmental friendliness, and flexibility. Louisiana State University (LSU) recently began operation of a new 20 MW cogeneration system. This new facility can serve as a useful learning tool for chemical and mechanical engineering students throughout their education at LSU. The goal of this project is to develop educational modules utilizing the cogeneration system which have industrial significance. Educational modules will include: a comparison of ideal gas versus real gas thermodynamics for a cogeneration optimization problem, a cogeneration data reconciliation problem, and a …

[Delta] Iddq Testing Of A Cmos 12-Bit Charge Scaling Digital-To-Analog Converter, Kalyan Madhav Golla

LSU Master's Theses

This work presents design, implementation and test of a built-in current sensor (BICS) for ∆IDDQ testing of a CMOS 12-bit charge scaling digital-to-analog converter (DAC). The sensor uses power discharge method for the fault detection. The sensor operates in two modes, the test mode and the normal mode. In the test mode, the BICS is connected to the circuit under test (CUT) which is DAC and detects abnormal currents caused by manufacturing defects. In the normal mode, BICS is isolated from the CUT. The BICS is integrated with the DAC and is implemented in a 0.5 μm n-well CMOS technology. …

A Nonlocal Model For Coupled Damage-Plasticity Incorporating Gradients Of Internal State Variables At Multiscales, Robert J. Dorgan

LSU Doctoral Dissertations

The thermodynamically consistent formulation and the subsequent numerical implementation of a gradient enhanced continuum coupled damage-plasticity model as a constitutive framework to model ill-posed localization problems is presented. By the introduction of "nonlocal," gradient-enhanced measures in the plasticity potential function and yield criterion and in the damage potential function and damage criterion, the proposed model introduces microstructural characteristic material length scales which allows the size of localized zones to be predicted based on material constants, as opposed to local models where the loss of ellipticity causes the localized zones to be mesh dependent.
The gradient model proposed introduces non-linear functions …

Experimental And Computational Analysis Of Random Cylinder Packings With Applications, Wenli Zhang

LSU Doctoral Dissertations

Random cylinder packings are prevalent in chemical engineering applications and they can serve as prototype models of fibrous materials and/or other particulate materials. In this research, comprehensive studies on cylinder packings were carried out by computer simulations and by experiments. The computational studies made use of a collective rearrangement algorithm (based on a Monte Carlo technique) to generate different packing structures. 3D random packing limits were explored, and the packing structures were quantified by their positional ordering, orientational ordering, and the particle-particle contacts. Furthermore, the void space in the packings was expressed as a pore network, which retains topological and …

Spectral Analysis Of Total Suspended Solids Mixtures For Solids Composition Determination, Curtis W. Sutherland

LSU Doctoral Dissertations

Total Suspended Solids (TSS) analysis provides an initial and very basic measure for study and characterization of water quality. The present tedious procedures used for the identification of different solids constituents present in TSS and for the classification or insight into the origins of those solids are time-consuming and expensive. The research reported herein investigates the use of instrumental analysis using reflectance spectra of TSS as an attractive alternative to sufficiently characterize and identify TSS in a more rapid and economical method that could be used to study TSS transport and to identity TSS points of origin. For this investigative …

Design And Evaluation Of Automated, Continuous Culture Techniques For Brachionus Rotundiformis, Zhengzhong Zhang

LSU Doctoral Dissertations

A 40-L recirculating rotifer turbidostat (RRT) pilot system consisting of a rotifer reactor, biofilter, foam fractionator, feed container, harvester, and two air-lift pumps was designed to produce B. rotundiformis, a small (S-type) rotifer, that is increasingly demanded for production of small-gape marine finfish larvae. The system’s automatic monitoring (turbidity, pH, conductivity and temperature) and controlling (turbidity, pH, feeding and harvesting) were performed by a Rugid™ computer. A 4 (temperature) x 3 (salinity) study indicated that a 30oC/15 ppt treatment is the most favorable to the growth of B. rotundiformis. Under these conditions, the effect of harvest rate on rotifer system …

An Adaptive Multi-Scale Computational Method For Modeling Nonlinear Deformation In Nanoscale Materials, Wenming Wang

LSU Doctoral Dissertations

In this dissertation a coupled multi-scale computational model for simulating nonlinear deformation processes in crystalline metals at finite temperatures is developed. The computational model uses the finite element method to model the coarse scale response of the material. The constitutive response in the finite element will be modeled through interatomic potentials acting on the underlying homogeneous crystal lattice that characterizes its nanostructure. An adaptive remeshing technique is proposed to automatically delineate regions of severe deformation where homogeneity of the microstructure/deformation is violated. In these regions the finite element will be replaced by a set of deformed atoms which interact with …

Design And Fabrication Of Micro Transducers Using Cured Su-8 Polymer As Main Structural Material, Wen Dai

LSU Doctoral Dissertations

Polymer based micro-transducers have many advantages over the traditional silicon based micro-transducers, such as easy integration with metal structures, design flexibility, and low fabrication costs. The characteristics of micro-transducers include converting electrical signals to/from mechanical response, the ability to sustain loading, sensitivity to external excitation, and etc. Some of the difficulties in realizing these characteristics include: characterizing material mechanical properties, techniques for producing electrically conductive polymer structures, and reliable fabrication procedures. In this dissertation, research addressing these difficulties is presented. The developed techniques are demonstrated in the design and fabrication of a SU-8 polymer based comb-drive micro-actuator. The micro-actuator used …

A Plasticity-Damage Model For Plain Concrete, Umit Cicekli

LSU Doctoral Dissertations

A plastic-damage model for plain concrete is developed in this work. The model uses two different yield criteria: one for plasticity and one for damage. In order to account both for compression and tension loadings, the damage criterion is divided into two parts: one for compression and a second for tension. The superscripts (+) and (-) in this work are used to represent tension and compression cases, respectively. The total stress is decomposed into tension and compressions components. The total strain is decomposed into elastic and plastic parts. The strain equivalence concept is used such that the strains in the …

A Thermodynamic Model For Wear In Sliding Contact, Susheel Brahmeshwarkar

LSU Master's Theses

Consideration of wear, an irreversible phenomenon, is a very important criterion in design. The knowledge of wear and its behavior enables one to make major considerations to conceptualize and design efficient machinery components with enhanced performance and reliability. The present work deals with the introduction of a novel approach of correlating wear with the thermodynamic properties of the system. The approach involves relating wear to thermodynamic entropy flow in the system using the laws of thermodynamics. This relation is verified experimentally and theoretically by considering a sliding contact in a disk-on-disk configuration for two sets of contacting materials namely Bronze …

Physical Model Study Of The Effects Of Wettability And Fractures On Gas Assisted Gravity Drainage (Gagd) Performance, Wagirin Ruiz Paidin

LSU Master's Theses

The Gas-Assisted Gravity Drainage (GAGD) process was developed to take advantage of the natural segregation of injected gas from crude oil in the reservoir. It consists of placing a horizontal producer near the bottom of the reservoir and injecting gas using existing vertical wells. As the injected gas rises to the top to form a gas cap, oil and water drain down to the horizontal producer. Earlier experimental work using a physical model by Sharma had demonstrated the effectiveness of the GAGD process in improving the oil recovery when applied in water-wet porous media. The current research is an extension …

Performance Of Torus-Type Brushless Dc Motor With Winding Connected In Two And Three-Phase System, Dinakar Choppa

LSU Master's Theses

A torus-type permanent magnet brushless DC motor is the object of this thesis. The motor can operate with the winding connected either in two - phase or three - phase system. A comparative study of performance of the motor operating in these two systems is the objective of the thesis. To analyze the motor performance, the dynamic models of the motors operating with two - phase and three - phase motors have been proposed. The simulation of motor operation was carried out using the MATLAB/SIMULINK software package. A study of motors operation in steady state conditions has been done by …

Jet Impingement Cooling Configurations For Gas Turbine Combustion, Eric Ian Esposito

LSU Master's Theses

Impinging jets are commonly used to enhance heat transfer in modern gas turbine engines. Impinging jets used in turbine blade cooling typically operate at lower Reynolds numbers in the range of 10,000 to 20,000. In combustor liner cooling, the Reynolds numbers of the jets can be as high as 60,000. The present study is aimed at experimentally testing two different styles of jet impingement geometries to be used in backside combustor cooling. The higher jet Reynolds numbers lead to increased overall heat transfer characteristics, but also an increase in crossflow caused from spent air. The crossflow air has the effect …

Influence Of Typha Latifolia And Phragmites Communis Root Matter On Degredation Of Aged 1,2,3,4-Tetrachlorobenzene In Bayou Sediments, Elaiza Maria Alvarez

LSU Master's Theses

The purpose of this study was to investigate the effects of Typha latifolia and Phragmites communis root matter in degradation of sediments contaminated with aged 1,2,3,4- Tetrachlorobenzene (1,2,3,4-TeCB). In the present study, complete reductive dechlorination of 1,2,3,4-TeCB was observed in root matter systems, contrasting sediment with no roots present. Microcosms amended with Phragmites communis roots achieved the greatest first-order reaction rate constant over a 4-week period (0.113 d^-1, half-life time of 6.13 days). Typha latifolia roots also played an important role in reductive dehalogenation of 1,2,3,4-TeCB, although the first-order reaction rate constant observed within the same period of …

Two-Phase Flow In High Aspect Ratio, Polymer Microchannels For Reagent Delivery Applications, Estelle Evans

LSU Master's Theses

Multiphase flow in microfluidics is an increasingly growing field, especially in biotechnology. For instance, a steady-state slug flow would benefit lab-on-a-chip drug delivery methods. This flow would not only use minute amounts of reagents, but it would also decrease the sample processing time. Thus, researching a steady-state plug flow in a microchannel is beneficial to the drug delivery field. Five PMMA, directly-milled microchannels [2: Aspect Ratio 1 (with and without pressure ports, 2): Aspect ratio 2 (with and without pressure ports), and 1: Aspect Ratio 3 (without pressure ports)] were manufactured. These channels were then cleaned, and a PMMA cover …

Loading And Recovery Behavior Of The Human Lumbar Spine Under Static Flexion, Guntulu Selen Hatipkarasulu

LSU Doctoral Dissertations

Musculoskeletal disorders account for 32 percent of work related injuries and illnesses. Extensive studies have been conducted to understand and explore the factors that affect the development of musculoskeletal disorders to provide effective control strategies. One of the most important factors that allow effective control strategies is the biomechanical factors. Among the biomechanical risk factors, exposures to repetitive static and vibratory activities are known to result in musculoskeletal disorders. A ligamento–muscular reflex activity exists in humans and animals to stabilize the knee, shoulder, elbow, ankle joints, and spine. This reflex activity decreases over time when static loading is applied, which …

Refurbishment Of Louisiana State University Calibration Chamber, Ardita Dushi

LSU Master's Theses

This thesis focuses on the refurbishment of Louisiana State University calibration chamber. The testing equipments were checked and connected together to complete the calibration chamber system. The data acquisition system was upgraded to National Instruments (NI) SCXI system. Therefore, a compatible computer program language in LabVIEW was developed. LabVIEW is a programming language developed by NI that reads the data from the instruments, displays the data in graphical form, calculates the desired parameters, commands the transducer to apply the required pressure to the specimen, and saves the data at the desired frequency. The Anisotropic Modified Cam Clay Model (AMCCM) following …

Modeling And Fabrication Of A Microthermocouple Array, Adam Cygan

LSU Master's Theses

Cryobiology is the study of how living cells and tissues respond to freezing and exposure to subzero temperatures. Studies in this field are aimed toward improving methods of cryosurgery as well as the storage of cells and tissues. For example, one area of research is to link the biophysical cellular dehydration and intracellular ice formation in cells during tissue freezing to cell viability and mechanical properties after thawing. There is currently a method for measuring dehydration in cells as part of a tissue, but not an adequate method for measuring intracellular ice formation in tissues. A prototype device that would …

Instantaneously Trained Neural Networks With Complex And Quaternion Inputs, Adityan V. Rishiyur

LSU Master's Theses

Neural network architectures such as backpropagation networks, perceptrons or generalized Hopfield networks can handle complex inputs but they require a large amount of time and resources for the training process. This thesis investigates instantaneously trained feedforward neural networks that can handle complex and quaternion inputs. The performance of the basic algorithm has been analyzed and shown how it provides a plausible model of human perception and understanding of images. The motivation for studying quaternion inputs is their use in representing spatial rotations that find applications in computer graphics, robotics, global navigation, computer vision and the spatial orientation of instruments. The …

Enhanced Degradation Of Phenanthrene And Benzo(A)Pyrene In A Field-Contaminated Sediment Inhabited By Ilyodrilus Templetoni: A Microcosm Study, Marilou Montevirgen Nabatilan

LSU Master's Theses

The influence of the oligochaete Ilyodrilus templetoni on the degradation of phenanthrene and benzo(a)pyrene present in a field-contaminated sediment was studied in microcosm experiments. Results indicate an enhanced degradation of phenanthrene and benzo(a)pyrene in microcosms inhabited by I. templetoni. Total phenanthrene reduction was observed at an average of 9.78 % in worm microcosms, while no reduction was observed in the control microcosms. Benzo(a)pyrene reduction, on the other hand, was determined at 78.60 % and 30.04 % in worm and control microcosms, respectively. The lowest concentrations of these PAHs at the end of 97-day study were observed well below the surface …

A Configurable Decoder For Pin-Limited Applications, Matthew Collin Jordan

LSU Master's Theses

Pin limitation is the restriction imposed on an IC chip by the unavailability of a sufficient number of I/O pins. This impacts the design and performance of the chip, as the amount of information that can be passed through the boundary of the chip becomes limited. One area that would benefit from a reduction of the effect of pin limitation is reconfigurable architectures. In this work, we consider reconfigurable devices called Field Programmable Gate Arrays (FPGAs). Due to pin limitation, current FPGAs use a form of 1-hot decoder to select elements (one frame at a time) during partial reconfiguration. This …

A Novel Robust Mel-Energy Based Voice Activity Detector For Nonstationary Noise And Its Application For Speech Waveform Compression, Syed, Q. Waheeduddin

LSU Master's Theses

The voice activity detection (VAD) is crucial in all kinds of speech applications. However, almost all existing VAD algorithms suffer from the nonstationarity of both speech and noise. To combat this difficulty, we propose a new voice activity detector, which is based on the Mel-energy features and an adaptive threshold related to the signal-to-noise ratio (SNR) estimates. In this thesis, we first justify the robustness of the Bayes classifier using the Mel-energy features over that using the Fourier spectral features in various noise environments. Then, we design an algorithm using the dynamic Mel-energy estimator and the adaptive threshold which depends …

Pulsed Vertical Jet In Cross Flow At Mean Blowing Ratios 0.35 And 0.45, Pierre-Emmanuel Jacques Joseph Bouladoux

LSU Master's Theses

This thesis deals with a pulsed vertical jet transverse to a cross flow (U_∞=1.6m/s) at mean blowing ratios 0.35 and 0.45. First the reasons of this study are explained and the previous work in the field is described. Then the experimental setup, the experimental procedures and the data processing are detailed. The system (wind tunnel and jet) is characterized before studying the Jet in Cross Flow (JICF). The JICF is explored under unforced and forced conditions through LASER sheet visualizations and constant temperature anemometry (CTA) measurements using hot-wire sensors. Blowing ratios ranging from 0.150 to 0.600 are studied …

Frictional Interaction Properties Between Geomaterials And Geosynthetics, Julian Javier Coronel

LSU Master's Theses

Soil reinforcement interaction is a primary issue for designing reinforced soil structures. The soil to geosynthetic interaction parameters are influenced by a) Interaction mechanism between geomaterials and geosynthetics (pull-out or direct shear), b) Physical and mechanical properties of geomaterials (density, grain shape and size, grain size distribution, water content, and plasticity of clayey soils), and c) Mechanical properties (tensile peak strength), shape and geometry of geosynthetics. The soil to geogrid interface friction parameters (interface friction angle "δ" and adhesion "c_a") for different plasticity indexes, moisture contents, and dry densities were investigated. For this purposes, a large scale direct …

Heat/Mass Transfer In Rotating, Smooth, High Aspect-Ratio (4:1) Coolant Channels With Curved Walls, Eashwar Sethuraman

LSU Master's Theses

The thesis presents an experimental study of heat/mass transfer coefficient in 4:1 aspect ratio smooth channels with non-uniform cross-sections. Curved leading and trailing edges are studied, for two curvatures of 9.06 m-1 (0.23 in-1) and 15.11 m-1 (0.384 in-1) and for two different curvature configurations. One configuration has curved walls with curvature corresponding to the blade profile (positive curvature on both leading and trailing walls), and the other configuration has leading and trailing walls that curve inwards into the coolant passage (negative curvature on the leading surface and positive curvature on the trailing surface). The experiments are conducted in a …