Engineering Commons^™

Differential Gene Expression In A Louisiana Strain Of Microalgae, John Joseph Tate

LSU Master's Theses

Considerable interest in alternative energy has stimulated research in biofuels, particularly microalgal biofuels. In particular, strains of algae that accumulate lipids to be used for biofuels must be adapted to outdoor growth and resistant to invasive species. Differential gene expression in a Louisiana algae/cyanobacteria co-culture consisting of approximately 97% Chlorella vulgaris and 3% Leptolyngbya sp. possessing these traits was examined. Possible reasons for the enhanced growth of the co-culture relative to a Chlorella monoculture were reviewed, including cyanobacterial symbiosis and chemicals produced by cyanobacteria or bacteria that could influence the growth of Chlorella. The co-culture and Chlorella monoculture were cultivated …

Bacterial Dehalogenation Of Mixtures Of 1,2-Dichloroethane, 1,2-Dichloropropane, And 1,1,2-Trichloroethane By Dehalogenimonas, Jacob Laddye Dillehay

LSU Master's Theses

The goal of the research presented here was to assess the ability of two bacterial strains, Dehalogenimonas lykanthroporepellens BL-DC-9T and Dehalogenimonas strain IP3-3, to reductively dehalogenate four contaminant mixtures comprised of combinations of the chlorinated solvents 1,2-dichloroethane (1,2-DCA), 1,2-dichloropropane (1,2-DCP), and 1,1,2-trichloroethane (1,1,2-TCA). Both of these bacteria were first isolated from contaminated groundwater at the PetroProcessors of Louisiana, Inc. Superfund site located near Baton Rouge, LA and are of interest because of their novel abilities to transform halogenated alkanes. In previous work (Yan et al., 2009, Bowman et al., 2012), it was demonstrated that both strain IP3-3 and D. lykanthroporepellens …

Linear Pm Generator For Wave Energy Conversion, Rajkumar Parthasarathy

LSU Master's Theses

The main objective of this thesis is to design a selected version of linear PM generator and to determine the electromechanical characteristics at variable operating conditions. To reach this objective, the linear generator with quasi-flat linear machine structure was selected and designed using the magnetic circuit theory. By applying 2-D and 3-D FEM the magnetic circuit was optimized and parameters of equivalent circuit were determined. The performance of generator operation are analyzed in steady-state and in dynamic conditions using MATLAB/SIMULINK. The analysis has been carried out at the secondary variable speed, which is changing sinusoidally according to the motion of …

Efficient Finite Element Modeling Of Reinforced Concrete Columns Confined With Fiber Reinforced Polymers, Dan Hu

LSU Master's Theses

Fiber reinforced polymer (FRP) composites have found extensive applications in the field of Civil Engineering due to their advantageous properties such as high strength-to-weight ratio and high corrosion resistance. This study presents a simple and efficient frame finite element (FE) able to accurately estimate the load-carrying capacity and ductility of reinforced concrete (RC) circular columns confined with externally bonded fiber reinforced polymer (FRP) plates and/or sheets. The proposed FE considers distributed plasticity with fiber-discretization of the cross-sections in the context of a force-based (FB) formulation. The element is able to model collapse due to concrete crushing, reinforcement steel yielding, and …

Pdms Based Waveguides For Microfluidics And Eocb, Weiping Qiu

LSU Master's Theses

Due to the low cost, fast and ease of molding, PDMS has become one of the most popular materials for microfluidics devices, bioMEMS applications. Meanwhile, the integration of different functional components on to one single chip (or Lab on a Chip) is the dream for many scientists and engineers in the related area. In addition to the necessary mechanical components for accommodating the reactions, such as pumps, valves, mixers and so on, optical components such as waveguides, lens, interferers are all desired to be lumped into such a system.

The waveguide for such a system requires the material to have …

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. …

Replenishment Policies For A Tree-Type Three Echelon Supply Chain System, Ratkrit Rochanaluk

LSU Master's Theses

One of the common goals which most companies have is to maximize profits. There are two way to increase profit: increasing revenue or reducing cost. Lacking of ability to keep the cost down could potentially drive the companies out of the business. In recent years, many researchers have been paying more attention on improving supply chain system due to high potential of creating cost savings. The supply chain network considered in this research is a tree-type, three-echelon single producer, multiple distributors, and multiple retailers system. The goal of this research is to develop a replenishment policy which satisfies customers’ demand …

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 …

Pavement Structural Evaluation Using The Rolling Wheel Deflectometer, Ahmed Moustafa Abdel-Khalek

LSU Master's Theses

The Rolling Wheel Deflectometer (RWD) offers the benefit to measure pavement deflection without causing any traffic interruption or compromising safety along the tested road segments. This study describes a detailed field evaluation of the RWD system in Louisiana in which 16 different test sites representing a wide array of pavement conditions were tested. Measurements were used to assess the repeatability of RWD measurements, to examine the effect of truck speeds, and to study the relationship between RWD and FWD deflection measurements and pavement conditions. Based on the results of the experimental program, it was determined that the repeatability of RWD …

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 …

Supercritical Pyrolysis Of Toluene, Khue Dang Nguyen

LSU Master's Theses

The development of future high-speed aircrafts will required the jet fuel to act as the primary engine coolant to absorb excess heat produced by the engine components. To aid in removing the excess heat and reducing the aircraft’s weight, future jet fuels used for high-speed aircrafts will act as both coolant and fuel; however, by exposing the fuels to temperatures and pressures above their critical point, they undergo pyrolysis to form larger and/or more abundant polycyclic aromatic hydrocarbons (PAH) and eventually carbonaceous solid deposits in the pre-combustion environment. The formation of solid deposits in the pre-combustion environment results in clogging …

Developing A Tool To Characterize The Ultradian Rhythm In Diploid Saccharomyces Cervisiae Using The Reporter Gene Green Fluorescent Protein, Imran Chiragh

LSU Master's Theses

Biological rhythms control many temporal behaviors of organism, such as the sleep cycle, hearts rhythms, seasonal animal migrations etc. Understanding these rhythms would provide insight into the temporal process of living organisms. Saccharomyces cerevisiae, a budding yeast, is an ideal model organism to study biological rhythms in eukaryotic cells because of its sequenced genome and discerned processes. By characterizing the biological rhythm in budding yeast, insight can be gained into more complex organisms. Previous studies have exhibited oscillatory behavior of oxygen consumption and determined that deletion of the GTS1 gene dissipates this rhythm. However, to further understand the specific behavior …

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 …

Simulation Study Of Sweep Improvement In Heavy Oil Co2 Floods, Venu Gopal Rao Nagineni

LSU Master's Theses

Enhanced oil recovery by CO2 injection is a common application used for light oil reservoirs since CO2 is relatively easily miscible with light oils. CO2 flooding in heavy oil reservoirs is often uneconomic due to unfavorable mobility ratios. Reservoir heterogeneity further complicates the process as CO2 channels through high permeability layers leading to premature breakthrough. However, this can be controlled by choosing a suitable modification to the CO2 injection process enabling better sweep efficiencies, and making the process economic. The current work focuses on two such methods; water-alternating-gas injection (WAG) and profile modification by blocking gas flow in the high …

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 …

Development And Validation Of Biomechanical Models To Quantify Horse Back Forces At The Walk In Three Horse Breeds, Laxmi Raghunandana Kaidapuram

LSU Master's Theses

Therapeutic horseback riding is a common component of physical therapy programs. Quantification of the horse back forces will provide vital information to match therapeutic riders with equine partners. To meet this medical need, a model to quantify the horse back forces from ground reaction forces was developed to test the hypothesis that the forces transferred to a static weight on the horse’s back can be predicted given horse breed and weight. Simultaneous, real time kinetic, kinematic, and back force data on a static weight were collected from 7 adult horses: 3 thoroughbreds, 3 quarter horses, and 1 paso fino. An …

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 …