Engineering Commons^™

Decoupling User Interface Design Using Libraries Of Reusable Components, Rajesh Sankaran

LSU Doctoral Dissertations

The integration of electronic and mechanical hardware, software and interaction design presents a challenging design space for researchers developing physical user interfaces and interactive artifacts. Currently in the academic research community, physical user interfaces and interactive artifacts are predominantly designed and prototyped either as one-off instances from the ground up, or using functionally rich hardware toolkits and prototyping systems. During this prototyping phase, undertaking an integral design of the interface or interactive artifact’s electronic hardware is frequently constraining due to the tight couplings between the different design realms and the typical need for iterations as the design matures. Several current …

On The Thermodynamics Of Degradation, Mehdi Amir Darehbidi

LSU Doctoral Dissertations

All materials when subjected to fatigue loading are prone to failure if the number of cycles exceeds a certain level. Prediction of the number of cycles to failure is, therefore, of utmost importance in nearly all engineering applications. The existing methods for evaluating the fatigue life are tedious, expensive, and extremely time consuming as fatigue often takes many thousands to millions of cycles until failure occurs. Therefore, methods that can readily estimate the number of cycles to failure are highly desirable. In this work, innovative solutions to fatigue problems are presented and their practical significance is discussed. The premise of …

Damage Detection And Identification In Fiber Reinforced Plastic Structural Members And Field Bridges Using Acoustic Emission Technique, Archana Nair

LSU Doctoral Dissertations

With the increased use of fiber reinforced polymer (FRP) based structural systems for rehabilitation of existing and construction of new bridges there is a requirement for identification of critical components of these structural systems and the determination of critical damage thresholds in them. Of the many available non-destructive techniques (NDT), acoustic emission (AE) monitoring had been identified as one of the most popular techniques applicable for damage discrimination in composites. The current study aimed at using patterns in AE data for the identification of damage modes exhibited by composite structural systems. The extensive experimental program involved testing of two structural …

Catalytic Hydrogenation Of Co To Higher Alcohols, Nachal Devi Subramanian

LSU Doctoral Dissertations

The interest in converting synthesis gas to alcohols and oxygenated fuel additives via CO hydrogenation is growing rapidly due to the increasing rise in oil prices. Among the potential end products, ethanol is desirable since it serves as a clean alternative fuel, a gasoline blend, and a hydrogen carrier to supply fuel cells. The high cost and limited availability of the most active/selective Rh-based catalysts has led to the development of base metal catalysts such as modified Cu-based catalysts. Literature suggests that a combination of Co (or Mn) with Cu can facilitate higher alcohol formation by a non-dissociative adsorption of …

Bio-Implantable Microdevices And Structures For Functional Electrical Stimulation Applications, Naga Srinivas Korivi

LSU Doctoral Dissertations

This dissertation describes the development of microstructures and devices for applications in functional electrical stimulation. A nerve cuff electrode design has been developed for applications in neural electrical stimulation and recording, which addresses limitations with existing cuff electrodes. The developed clip-on micro-cuff electrode design consists of a naturally closed cuff with inner diameter in the micro-scale or above. A novel pinch-hinge feature allows a user to easily open the cuff and place it on target nerve tissue for stimulation or recording purposes. Upon release of the pinch-hinge, the cuff assumes its normally closed nature. The device conducts and reads electrical …

Photoelectrochemical Etching Of Isolated, High Aspect Ratio Micorstructures In N-Type Silicon (100), Purnima Narayanan

LSU Master's Theses

Three-dimensional integration techniques have become increasingly popular to meet the ever rising demand of high capacity and reduced package size in microelectronics devices. Through Silicon Vias (TSVs) offer an efficient method to achieve 3D packaging with shorter interconnection length and higher interconnect density relative to conventional wire bonding. Wet electrochemical etching is a simple technique which may be used to create deep structures in silicon and is relatively low cost compared with Reactive Ion Etching or Laser drilling. Historically, a primary challenge is passivating TSV (macropore, microstructure) sidewalls against etching at sidewall thickness greater than twice the depletion region width. …

Evaluation Of Louisiana Asphalt Pavement Friction, Vivek Lal Das

LSU Master's Theses

This study aims to comprehensively investigate the effect of asphalt mix designs to address skid resistance. The current Louisiana Department of Transportation and Development (LADOTD) specification for friction design considers only the friction rating of aggregate defined by the polished stone value (PSV) obtained by the British pendulum tester (BPT), which is associated with only the micro-texture of asphalt pavement surfaces. The objective of this study is to recommend an asphalt surface friction mix design guideline which is based on both micro- and macro-texture of the wearing course mix. The objective was achieved by evaluating four typical laboratory prepared Louisiana …

Electrochemical Reduction Of Co2 To Methanol, Minh Tuyen Hoang Le

LSU Master's Theses

An efficient method to convert CO2 to fuels using renewable energy could displace crude oil without increasing CO2 emission and provide high-density energy storage reservoirs similar to liquid fuels or batteries. Although photoelectrochemical conversion of CO2 is possible, solar-to-fuel efficiencies are lower than the combination of conventional photovoltaics (up to 40% efficiency) and electrochemical cells (up to 80% Faradaic efficiency). In the electrochemical case, electrical energy from renewable sources may be converted to hydrocarbons or alcohols using electrocatalysts. The direct reduction of CO2 to CH3OH is known to occur at several types of electrocatalysts including oxidized Cu electrodes. In this …

Modeling Effects Of Coupled Convection And Co2 Injection In Stimulating Geopressured Geothermal Reservoirs, Tatyana Plaksina

LSU Master's Theses

Geopressured geothermal brines are a vast geothermal resource in the US Gulf of Mexico region. In particular, geopressured sandstones near salt domes are potential sources of geothermal energy because salt diapirs with high thermal conductivities may pierce younger, cooler strata. These characteristics enhance transfer heat from older, hotter strata at the base of the diapir into shallower strata. Moreover, widespread geopressure in the Gulf region tends to preserve permeability, enhancing productivity. As an example, the Camerina A sand of South Louisiana was chosen as a geomodel for a numerical simulation study of effects of CO2 injection and coupled convection as …

Analysis Of Major Hydrologic Events In Ascension Parish, La, Jessica Irene Mason

LSU Master's Theses

Ascension Parish is located in Southern Louisiana and is characterized by low slope and low elevation. This combination allows for much hydrologic storage during a flood event. Because Ascension Parish is one of the most rapidly growing areas in the United States, it is necessary to accurately predict the hydrologic and hydraulic properties of flow and accurately model them. Several processes within a hydrologic model greatly influence the output flow hydrographs so selecting correct methods and parameters is important. Transform methods describe how excess precipitation is transformed into runoff. There are several methods that can be used as a transform …

Using X-Ray Computed Tomography To Quantify Damage Of Hot-Mix Asphalt In The Dynamic Complex Modulus And Flow Number Tests, Hao Ying

LSU Master's Theses

The dynamic modulus test is conducted based on the assumption that no damage is induced during the testing process and that measurements are conducted within the linear viscoelastic region. In addition, significant damage is expected to occur during the flow number test process. While these assumptions are well-defined, the levels of damage taking place during these tests have not been quantified. The objectives of this study were to quantify the levels of damage in the dynamic complex modulus and flow number tests using x-ray computed tomography (CT) and to characterize the microstructural properties of asphalt mixtures under loading. Four Superpave …

Interfacial Shear Bond Strength Between Old And New Concrete, Zhifu Wan

LSU Master's Theses

The quality of the bonded concrete overlay depends on the bonding at the layer’s interface, which is affected by water to cement (w/c) ratio in new concrete, moisture condition of old concrete surface. The objective of this study is to quantify the interface shear bond strength affected by these variables. At the Phase I, twelve old concrete cubes with two different moisture conditions (air dry, saturated surface dry (SSD)) at the interface were chosen. Silica fume addition with two w/c ratios of 0.45 and 0.6 were used for new overlay concrete. It was found that silica fume significantly increased both …

Effect Of Piezoelectric Actuation On Curved Beams And Single Lap Joints, Calicia Johnson

LSU Master's Theses

Piezoelectric materials have seen a significant usage increase over the past decade. They have been found to be effective as either sensors or actuators in smart structure applications, which allows them to act more as an adaptive system rather than a passive system. Piezoelectric materials are very effective transducers which convert mechanical energy into electrical energy, known as the direct piezoelectric effect or they have the ability to convert electrical energy to mechanical energy, known as the converse piezoelectric effect. The absence of additional mechanical parts, its lightweight and high strength to weight ratio is what make piezoelectric materials so …

The Effects Of Highway Environmental Conditions On Photocatalytic Pavement's Ability To Reduce Nitrogen Oxides, Heather Dylla

LSU Master's Theses

Nitrogen oxides (NOx) emitted from vehicle exhaust are associated with negative health impacts and are a precursor to ozone. Self-cleaning, air-purifying concrete pavement is a rapidly emerging technology that can degrade pollutants such as NOx through heterogeneous photocatalysis. Although this technology has the potential to support environmentally friendly road infrastructure, a number of design and operational parameters may affect its effectiveness and thus need to be evaluated. The goal of this study was to measure the NOx reduction efficiencies from photocatalytic pavements under various environmental conditions common to highways. To achieve this goal, the objectives were to: (a) evaluate the …

Stochastic Modelling Of Eukaryotic Cell Cycle, Murali Krushna Koneru

LSU Master's Theses

Stochastic models are developed to capture the inherent stochasticity of the biochemical networks associated to many biological processes. The objective of the present thesis is to present a detailed picture of stochastic approach for the mathematical modeling of eukaryotic cell cycle, to demonstrate an important application of such model in chemotherapy and to present a methodology for selecting the model parameters. The stochastic cell cycle model, developed using stochastic chemical kinetics approach, leads to the formation of an infinite dimensional differential equation in probabilities of system being in a specific state. Using Monte Carlo simulations of this model, dynamics of …

The Design And Modification Of A Sputter System For Dc Reactive Sputtering Of Alumina And Zirconia Thin Films, Diane Van Ho

LSU Master's Theses

Yttria-stabilized zirconia (7% YSZ) is the most used material for thermal barrier coatings (TBCs) to reduce the conductive heat transfer on turbine blades, but it is not resistant to infrared radiation. In order to reduce radiation heat transfer, alternating materials, such as alumina and zirconia, can be used to fabricate multi-layer coatings in which each layer is optimized to reflect a targeted range of wavelength. This research aims to fabricate these multi-layer coatings by reactive magnetron sputtering. Reactive magnetron sputtering is the sputtering of an elemental target in the presence of a reactive gas that will react with the target …

A Study On The First-Passage Reliability Problem And Its Application In Earthquake Engineering, Sara Ghazizadeh

LSU Master's Theses

The research presented in this thesis focuses on analytical approximations for the time-variant first-passage failure probability (FPFP) of linear elastic models of structural systems subjected to stochastic excitations. The FPFP is defined as the probability that a response quantity of an engineering system subjected to a dynamic stochastic loading outcrosses a specified threshold within a given exposure time. The FPFP is an important and useful quantity for many structural engineering applications. The classical first-passage reliability problem is studied for linear elastic single-degree-of-freedom (SDOF) and multi-degrees-of-freedom (MDOF) systems subjected to stationary and nonstationary Gaussian excitations. The absolute and relative accuracy of …

Performance Of Control Room Operators In Alarm Management, Dileep Buddaraju

LSU Master's Theses

Pipelines transport millions of barrels of petroleum products every day. These systems have significant safety concerns. The BP oil spill in the Gulf of Mexico, while concerned with oil and gas extraction rather than distribution, shares many of the same safety and reliability issues as distribution systems, and demonstrates the significant potential for major disasters in the pipeline industry. In this work, a research study is being conducted to further understanding of the role of operators in the management of alarm systems and to measure the performance of operators in handling abnormal situations like pressure loss, liquid inflow/outflow variation and …

Performance Of Twin-Rotor Dc Homopolar Motor, Zhiwei Wang

LSU Master's Theses

A new concept of dual-rotor motor with counter-rotating propeller increases the efficiency of the ship propulsion used in marine industry. This concept can be realized by twin-rotor permanent magnet homopolar disc motor, which is the object of this thesis. The objectives of this thesis are to determine the motor electromechanical parameters applying a 3-D FEM modeling and to analyze the motor performance in steady-state and dynamic conditions. The objectives of this thesis are to determinate the PM DC homopolar twin-rotor disc motor electromechanical parameters by 3-D FEM modeling. Furthermore, the PM DC Homopolar perform determination in steady-state and dynamic conditions. …

Application Of Satellite Remote Sensing Imagery To Bridge Scour Evaluation, Xiaoyan Zhao

LSU Master's Theses

The overall goal of this research is to evaluate the applicability of the existing HEC-18 method to Louisiana bridges that are mostly situated on cohesive soils and hence to develop a more reliable design method for scour depth and scour rate prediction. Pier research in sandy soils and cohesive soils shows that the sandy soils are known to erode particle by particle, while cohesive soils usually erode in clumps rather than individual particles, which is caused by from the different bonding mechanisms between sandy soils and cohesive soils. Because the bonding in cohesive soils is so complex, the prediction of …

Screening Of Tar Cracking Catalysts For Syngas Produced By Biomass Gasification, Bijeet Mukherjee

LSU Master's Theses

The gasification of biomass produces tars and particulates. These tars and particulates create problems in the gasification systems. Tars condense on surfaces at lower temperatures, such as exit pipes and on particulate filters, leading to blockages and clogged filters. Tars also have varied impacts on other downstream processes. Due to these reasons, syngas containing significant concentrations of tars cannot be used in internal combustion engines. Thus the processes through which tars can be removed have been subject to considerable research. The objective of this research was to identify the best catalyst for for down-draft gasifiers, including the LSU AgCenter down-draft …

The Transient Wave Effect And Real Losses Correlation-Frequency, Temporal, And Spatial Analysis, Dina Sa Knight

LSU Master's Theses

Water distribution systems are prone to transients since pumps need to be started and stopped, pumps may have sudden flow changes, human blunders can occur, equipment may fail, or other unavoidable natural events may ensue. Surge modeling techniques are available to calculate variations in pressure, under extreme or normal operating conditions, serving as a tool to predict extreme events in order to design a suitable system and, or, to aid in the implementation of proper measures to mitigate transients. However, modeling an entire water network system may not be cost effective and may require extensive research and time especially in …

Back-End Processing Of Scanning Mirrors With Scratch Drive Actuators, Pradeep Pai

LSU Master's Theses

The use of micro-electro-mechanical system (MEMS) processes in fabrication of micr- electro-mechanical devices for optical applications has been widespread. The invention of digital light processing (DLP) technology by Texas Instruments Inc. popularized the use of micro-mirrors. One of the applications of the micro-mirrors is in the form of scanners for biomedical imaging. The small size of mirrors and actuators makes them a good candidate for in vivo measurements/imaging. Various techniques in bulk- and surface-micromachining, and various actuators have been used to fabricate scanning mirrors. The scanning mirrors used in this work make use of scratch drive actuators (SDA) for their …

Integrating Demand And Traffic Simulation Modeling To Evaluate Adaptive Evacuation Plans, Thomas Jude Montz, Jr.

LSU Master's Theses

Significant efforts are currently being made by transportation officials to improve the planning and preparation of mass evacuations. The idea of adaptive evacuation plans is an avenue of research that could help improve future evacuation processes. Adaptive evacuation plans stem from the observation that different disaster threat scenarios require different evacuation responses. While adaptive evacuation planning can be generalized to any form of evacuation planning, this project focused on adaptive planning in the context of a hurricane evacuation.

This project was the first to adapt the demand models of Fu, et al, and Cheng, et al, into a regional-scale traffic …

An Euler Solver For Nonlinear Water Waves Using A Modified Staggered Grid And Gaussian Quadrature Approach, Qi Fan

LSU Master's Theses

A structured, finite-volume Euler solver for non-hydrostatic, free surface flows is developed to simulate coastal nonlinear dispersive water waves. A semi-implicit projection method which splits the pressure term into hydrostatic and non-hydrostatic parts is employed. A vertically shifted, staggered grid is designed to accommodate a new Gaussian discharge calculator and to facilitate the enforcement of a non-hydrostatic free-surface boundary condition. The Gaussian discharge calculator on the shifted grid increases the dispersion accuracy compared to traditional approaches that calculate discharges on a regular staggered grid. Numerical results are presented to demonstrate the improvements of these methods.

Molecular Dynamics Of Ionic Liquids In Nanoporous Electrodes, Nav Nidhi Rajput

LSU Master's Theses

Molecular dynamics simulations were performed to investigate the structural and dynamical properties of ionic liquid (IL) [EMIM+][TFMSI-] confined inside slit-like graphite pores. ILs are salts composed of an organic cation and an organic or inorganic anion with melting point below 100ºC. Their unique properties such as great thermal and chemical stability have gained them immense attention in recent years. The main goal of this research is to understand how molecular level properties of ILs are affected by the properties of the nanoporous materials. The results obtained in this work indicate that pore size has a profound effect on structural and …

Fault Detection In Process Control Plants Using Principal Component Analysis, Vamshi Krishna Kandula

LSU Master's Theses

The aim of this thesis is to use a statistical method (principal component analysis) to detect a fault in a system. PCA is a dimensionality reduction technique that is used here. First the PCA algorithm was implemented on a simple two dimensional random data to reduce its dimensionality. Then the algorithm was implemented on a three dimensional data from a linear first order process and introduce some white noise later on and compare the results with that under normal operating conditions, thus determining the presence of a fault. Then data from a real time plant is considered for testing. This …

Surface-Enhanced Raman Spectroscopy Substrates Based On Nanoporous Silicon And Pattern Transfer, Pallavi Rao Malempati

LSU Master's Theses

Surface-enhanced Raman scattering enhances the weak Raman scattering by using a roughened metal-coated surface as a catalyst. Roughness in the nanometer range provides the best enhancement. The nanostructures for the surface-enhanced Raman spectroscopy (SERS) substrates, in this work, are generated using an electrochemical etching process on silicon substrates. The patterns of nanoporous silicon thus generated are transferred onto transparent polydimethylsiloxane (PDMS) substrates using the “lift-off” process. An incomplex sputtering technique is employed to coat this substrate with a ~20 nm aluminum layer. Rhodamine 6G (R6G) molecules, when adsorbed to this metal surface, form the final SERS substrate that undergoes Raman …

Smart Access Control System With Behavioral Profiling And Dynamic Pin Concept, Lohit Penubaku

LSU Master's Theses

Since ancient time, an access control device has been used for securing valuable properties as well as lives from threatening peoples. The most representative security device is Lock/Key. Recently, those security device technologies have been improved tremendously and provided various types of security methods. Nevertheless, these methods are not individually perfect to provide optimal security so that in recent years many such methods have been combined and used together to provide the required level of security. However, such combination can enhance security for limited number of users only but very difficult to provide scalable security with the number of users …

Two-Stage Biaxial Thermomechanical Cycle Of Shape Memory Polymer Based Syntactic Foam, Abraham Michael King

LSU Master's Theses

A shape memory polymer (SMP) is a polymeric material that exhibits shape memory behavior. It can be “programmed” to take on a desired shape and “recovered” to revert back to its original shape. This ability to remember multiple shapes and switch between them with the application of a stimulus from an outside source is very desirable in certain applications. By dispersing glass microspheres in a SMP matrix, a syntactic foam is created that retains much of the shape memory capabilities but has higher strength and lower density than the pure SMP. These characteristics make this material a good candidate for …