Engineering Commons^™

Fabrication, Characterization, Modeling And Testing Of A Nanostructured Bulk Thermoelectric Cooler, Dinesh Pinisetty

LSU Doctoral Dissertations

New generation micro/nano devices are emerging to monitor, control and act on living systems. Particularly, in the field of cryobiology, there is a need to monitor and control temperature at the cellular level. An important step towards achieving this aim is to fabricate a novel bulk nanostructured thermoelectric cooler (TEC). As a first step towards achieving efficient localized control of temperature in biological systems, Bismuth-telluride (Bi2Te3) and Antimony-Telluride (Sb2Te3) arrays of nanowires and nanotubes were fabricated, characterized and modeled. A thermal conductivity model originally developed by Dames and Chen for superlattice nanowires was extended to nanotubes. Based on this model …

Point-Of-Care Immunoassay System Using Carbon Nanotube Labels, Adeyabeba Abera

LSU Doctoral Dissertations

The goal of this research was to develop enhanced signal detection mechanisms for immunosensing using carbon nanotubes (CNTs). The utilization of CNT labels for direct electrical measurement was implemented on lateral flow system and microfluidic integrated interdigitated array microelectrodes. These sensing mechanisms in simple and miniaturized system provided higher sensitivity and autonomous flow control for rapid detection aimed at point-of-care diagnostics. Specific functionalization protocols were carried out to chemically modify the surface of the CNTs for uniform dispersion and antibody conjugation in aqueous solution. Surfactant assisted dispersion of the CNTs was studied using PVP and PEG. Covalent conjugation of antibodies …

Model-Based Nonlinear Control Of Active Tilting-Pad Bearings, An Wu

LSU Doctoral Dissertations

A promising mechanical bearing candidate for active operation is the tilting-pad bearing. The proposed active tilting-pad bearing has linear actuators that radially translate each pad. The use of feedback control in determining the actuator forces allows for the automatic, continuous adjustment of the pad position during the operation of the rotating machine. In the first part of the dissertation, we develop a nonlinear dynamic model of the active bearing system. The hydrodynamic force produced by the fluid film is modeled as a nonlinear, squeeze-film damper plus repellent spring. A model-based nonlinear controller is then designed to exponentially regulate the rotor …

Antioxidant Nanoparticles As Delivery Systems, Carlos Ernesto Astete R.

LSU Doctoral Dissertations

The goal of the study was to develop antioxidant polymeric nanoparticles as a new delivery system for food and pharmaceutical applications. Natural antioxidants like alpha-tocopherol, vitamin C, and carnosine, are responsible to protect biological systems against free radicals attack. The conjugation of vitamin C-vitamin E (EC) and alpha-tocopherol-carnosine (VECAR) were performed to obtain antioxidant surfactants which were used for polymeric nanoparticle synthesis. The surfactant made of á-tocopherol (vitamin E) and ascorbic acid (vitamin C) of antioxidant properties dubbed as EC was used to make poly(lactic-co-glycolic) acid (PLGA) nanoparticles. Self-assembled EC nanostructures and PLGA-EC nanoparticles were made by nanoprecipitation, and the …

The Effect Of Anisotropic Surface Energy On The Stability Of Micro And Nano Wires, Ping Du

LSU Doctoral Dissertations

A liquid thread of radius R will break up into drops if the axial wavelength of the surface perturbation L > 2πR. If L < 2πR, the thread is stable and will remain intact. This is Rayleigh’s stability criterion based on a continuum model. We use molecular dynamics to simulate the evolution of Lennard-Jones liquid threads with equilibrium radius R = 2.3-6.6, where R has been non-dimensionalized by the distance at which the Lennard-Jones potential equals zero. We find that if R is fixed, the wavelength L is bounded by L_min and L_max. For L > L_max the thread always breaks up and stays as drops, and for L < L_min the thread remains intact. However, for L_min < L < L_max, the thread oscillates continuously among several shapes. The appearance of various shapes can be explained by the energy fluctuation of the system.

We also simulate the evolution of Lennard-Jones nanowires with equilibrium radius R = 1.57, 2.58, 3.59, and 4.60 by molecular dynamics. The wires …

Characterization Of Rock/Fluids Interactions At Reservoir Conditions, Dayanand Saini

LSU Doctoral Dissertations

In this study, interfacial phenomena of spreading, wettability, and rock/oil adhesion interactions in complex rock/oil/water systems were characterized at reservoir conditions of elevated pressures and temperatures. Capabilities of both ambient and reservoir condition optical cells were used for measuring the oil/water interfacial tension and dynamic (the water-receding and the water-advancing) contact angles for various complex rock/oil/water systems. Well known sessile oil drop volume alteration method was successfully used in this study for evaluating the applicability of the modified Young’s equation for characterizing the line tension in complex rock/oil/water systems at reservoir conditions. This appears to be first time when rock/fluids …

Thermal Conductivity And Its Effects On The Performance Of Pcc Pavements In Mepdg, Upender Kodide

LSU Master's Theses

This study developed a standard thermal conductivity test procedure to test concrete specimens and studied factors influencing those specimens. The thermal conductivity of concrete is significantly affected by moisture content, type, and percentage of coarse aggregate; this finding was confirmed statistically by Analysis of Variance (ANOVA). The study also developed a model for predicting the thermal conductivity of concrete that varies with moisture content and the coarse aggregate percentage. To understand the effect of supplementary cementitious materials (SCMs), this study also measured thermal conductivity of control and ternary mixtures. An increase in thermal conductivity percentage due to increase in moisture …

Elastohydrodynamic Analysis Of Spur Gears Using Load-Sharing Concept: Running-In And Steady-State, Saleh Akbarzadeh

LSU Doctoral Dissertations

Gears are widely used in industry and hence their performance is of vital importance. Under the typical operating conditions of gears, the lubricant layer formed between the teeth of the pinion and the gear cannot completely separate the surfaces and contact of asperities of the pinion and gear occurs. This case is usually referred to as mixed lubrication problem. In this research the load-sharing concept has been employed to predict the performance of the pinion-gear system. The load-sharing concept is an efficient method to solve the mixed lubrication problem and is capable to predict the thickness of the lubricant film, …

Integrating Bioprocesses Into Industrial Complexes For Sustainable Development, Debalina Sengupta

LSU Doctoral Dissertations

The objective of this research is to propose, develop and demonstrate a methodology for the optimal integration of bioprocesses in an existing chemical production complex. Chemical complex optimization is determining the optimal configuration of chemical plants in a superstructure of possible plants based on economic, environmental and sustainable criteria objective function (triple bottomline) and solves a mixed integer non linear programming problem. This research demonstrated the transition of production of chemicals from non-renewable to renewable feedstock. A conceptual design of biochemical processes was converted to five industrial scale designs in Aspen HYSYS® process simulator. Fourteen input-output block models were created …

Estimated Impact Of Left Lane Truck Restriction On Louisiana Highway Pavement Using Mepdg, Mini Radhakrishnan

LSU Master's Theses

Truck lane restriction strategies (TLRS) are strategies used to manage truck traffic on highways by prohibiting trucks from using certain lanes in order to minimize interaction between trucks and other vehicles and currently it is under consideration for implementation in Louisiana’s multi-lane highways. One of the serious impacts of a truck lane restriction on highways is accelerated pavement damage on unrestricted lanes due to the increased truck traffic on them. The purpose of this study is to estimate the increased pavement damage on the right lane in terms of various distress caused by imposing left lane truck restriction on trucks …

Touch-Screen Sd Card Text Reader, Samia Rahman

Honors Capstones

No abstract provided.

Adhesion Of Jurkat Cells In Defined Media And Substrates, Sarah De Leo

Honors Capstones

No abstract provided.

Numerical Implementation Of Prandtl’S Lifting-Line Theory And Modeling Of Aircraft Take-Off Phase For Wing Optimization, John William Dykes

Honors Capstones

No abstract provided.

Site-Specific Deoxyribonucleic Acid Modifications For Use With Chemical Cages, John P. Casey Jr

Honors Capstones

No abstract provided.

Mechanical Optimization Of Vertical Axis Wind Turbine Blades, Alexander Laurence Combe

Honors Capstones

No abstract provided.

Intelligent-Navigating, Maze-Mapping, And Maze-Solving Robot Equipped With Sensors, Compass, And Gps System, Yunan Yuan

Honors Capstones

No abstract provided.

Impedance Spectroscopy Of Zebrafish Sperm, Robert Egnatchik

Honors Capstones

No abstract provided.

The In Vitro Characterization Of Chitosan-Plga Nanoparticle/Plasmid Dna Complexes, Hali Bordelon

Honors Capstones

No abstract provided.

A Self Healing Smart Syntactic Foam Based Grid Stiffened Sandwich Structure, Manu Kuruvila John

LSU Doctoral Dissertations

Syntactic foams are composite materials synthesized by dispersing microballoons in a polymeric, ceramic or metallic matrix. In the past three decades, syntactic foams have gained immense importance as a lightweight and damage-tolerant material when used in foam-cored sandwich structures. Because of the structural-length scale damages by low velocity impact such as tool drops, runway debris etc., sandwich structures usually have a very low residual structural capacity. Unfortunately, macro-length scale damage, in particular internal damage such as impact damage, is very difficult to repair. Therefore, there is a genuine need to develop impact-tolerant and self-healing syntactic foams which can be used …

State Feedback Control With Time Delay, Akshay Nareshraj Singh

LSU Doctoral Dissertations

In this thesis we start with an introduction to the theory of vibration control. We broadly classify the control methods into passive and active schemes. We introduce the problem of state feedback control and provide the classical solution in the form of Ackermann formula. We then identify the limitations of the classical approach and present the more elegant solution of partial pole assignment without spillover. We highlight the problem with model uncertainties and describe the method of pole assignment using data from measured receptances. This approach is extended for pole assignment for a linear vibrating system by using state feedback …

Copula-Based Multivariate Hydrologic Frequency Analysis, Hemant Chowdhary

LSU Doctoral Dissertations

Multivariate frequency distributions are being increasingly recognized for their role in hydrological design and risk management. The conventional multivariate distributions are severely limited in that all constituent marginals have to be from the same distribution family. The copula method is a newly emerging approach for deriving multivariate distributions which overcomes this limitation. Use of copula method in hydrological applications has begun only recently and ascertaining the applicability of different copulas for combinations of various hydrological variables is currently an area of active research. Since there exists a variety of copulas capable of characterizing a broad range of dependence, the selection …

Fault Detection Filter Design For Linear Systems, Xiaobo Li

LSU Doctoral Dissertations

This dissertation considers residual generation for robust fault detection of linear systems with control inputs, unknown disturbances and possible faults. First, multi-objective fault detection problems such as $\mathscr{H_-}/ \mathscr{H_\infty}$, $\mathscr{H}_2/\mathscr{H_\infty}$ and $\mathscr{H_\infty}/\mathscr{H_\infty}$ have been formulated for linear continuous time-varying systems (LCTVS) in time domain for finite horizon and infinite horizon case, respectively. It is shown that under mild assumptions, the optimal solution is an observer determined by solving a standard differential Riccati equation (DRE). The solution is also extended to the case when the initial state for the system is unknown. Second, the parallel problems are also solved for linear …

Modeling The Risk Factors Associated With The Neck Disorders During Manual Material Handling Tasks, Ashish D. Nimbarte

LSU Doctoral Dissertations

Work-related musculoskeletal disorders (MSD) of the neck or cervical spine result in longer sick leaves, substantial levels of human suffering, and high costs for society. Epidemiological studies clearly indicate strong associations between MSD of the neck and the work activities requiring forceful arm exertions and heavy lifting. However, studies evaluating the loading of the cervical spine during forceful arm exertions and heavy lifting tasks are limited. Major neck muscles, the sternocleidomastoid and the upper trapezius, run parallel to the cervical spine and couple the shoulder to the skull. It was hypothesized that such anatomical orientation may require these muscles to …

Quantitative Macro- And Microscale Methods For Characterizing Cell Viability, Julianne Forman Audiffred

LSU Doctoral Dissertations

The goal of this study is to combine molecular and microdevice methods to characterize and quantify viability of single mammalian cells. Fluorescent-based assays were optimized for adherent HeLa and suspension Jurkat cells and were used as a tool for validation of a microfabricated diagnostic device. Cell and substrate/surface interactions were considered for designing a microfluidic device that can be used to characterize cell viability for quantitative biomedical and cell biology applications, which require label-free, real-time monitoring of cells. Several interdisciplinary methods are employed to evaluate electrical impedance differences between live and dead Jurkat cells in a microfluidic device. Biological Micro-Electro-Mechanical …

Processor Design Space Exploration And Performance Prediction, Balachandran Ramadass

LSU Master's Theses

The use of simulation is well established in processor design research to evaluate architectural design trade-offs. More importantly, Cycle by Cycle accurate simulation is widely used to evaluate the new designs in processor research because of its accurate and detailed processor performance measurement. However, only configuration in a subspace can be simulated in practice due to its long simulation time and limited resources, leading to suboptimal conclusions that might not be applied to the larger design space. In this thesis, we propose a performance prediction approach which employs a state-of-the-art technique from experimental design, machine learning and data mining. Our …

Fatigue Fracture And Microstructural Analysis Of Friction Stir Welded Butt Joints Of Aerospace Aluminum Alloys, Vinay Raghuram

LSU Master's Theses

Friction-Stir-Welding (FSW) has been adopted as a major process for welding Aluminum aerospace structures. Al-2195, which is one of the new-generation Aluminum alloys that has been used on the external tank of the new super lightweight external tank of the space shuttle. The Lockheed Martin Space Systems (LMSS), Michoud Operations in New Orleans is continuously pursuing Friction-Stir-Welding technologies in its efforts to advance fabrication of the external tanks of the space shuttle. The future launch vehicles which will have to be reusable, m, an dates the structure to have good fatigue properties, which prompts an investigation into the fatigue behavior …

Progressive Water-Oil Transition Zone Due To Transverse Mixing Near Wells, Shengkai Duan

LSU Doctoral Dissertations

This study derives from observations made in petroleum research and practices of chemical industry that efficient mixing takes place in segregated immiscible fluid flow in granular packs and static mixers. A hypothesis was formulated that transverse mixing (TM) across oil-water interface may occur in segregated inflow to wells resulting in progressive transition zone, more water production, and reduced oil productivity. “Mixing” is broadly interpreted here to address the entire range of stirring, splitting, dispersion and diffusion processes between two fluids.

Initial study showed that a commercial reservoir simulator would not model any transition zone in segregated oil-water flow at high …

The Study Of Sediment Dynamics In A Shallow Estuary Using Integrated Numerical Modeling And Satellite Remote Sensing, Haihong Zhao

LSU Doctoral Dissertations

The primary objective of the study is to develop an effective tool to investigate the resuspension, deposition and transport of mixed cohesive and non-cohesive sediments in an estuary. The research has integrated 1) statistical analyses of the primary forcing, 2) numerical models for hydrodynamics, surface waves and sediment transport, and 3) the MODIS (Moderate Imaging Spectroradiometer) remotely sensed imagery, to investigate hydrodynamics and sediment dynamics in Mobile Bay, Alabama. First, based on long-term meteorological and tidal observations, statistical analyses have been conducted to predict extreme values of winds and water levels at different return periods in the estuary. Application of …

Residential Building Damage From Hurricane Storm Surge: Proposed Methodologies To Describe, Assess And Model Building Damage, Carol J. Friedland

LSU Doctoral Dissertations

Although hydrodynamic models are used extensively to quantify the physical hazard of hurricane storm surge, the connection between the physical hazard and its effects on the built environment has not been well addressed. The focus of this dissertation research is the improvement of our understanding of the interaction of hurricane storm surge with the built environment. This is accomplished through proposed methodologies to describe, assess and model residential building damage from hurricane storm surge. Current methods to describe damage from hurricane events rely on the initiating mechanism. To describe hurricane damage to residential buildings, a combined wind and flood damage …

Stability Of Articulated Revetments Against Wave Attack On Shallow Soft Soil Slopes, Edmond Joseph Russo

LSU Doctoral Dissertations

Continuously-connected, articulated revetment systems have potential to decrease the weight of armor cover in resisting wave attack, compared to traditional designs. Modes of instability for sloping revetments include uplift, sliding, and toe roll-up. Design methods are summarized by McDonnell (1998), Pilarczyk (1998), and Herbich (1999). Russo (2003) conducted a field prototype scale investigation on performance of Articulated Concrete Mattresses (ACMs) in coastal Louisiana, which demonstrated this structure’s ability to resist a range of wave loading conditions, and inspired scoping of further research to quantify structure performance beyond known limits. Present research expanded earlier works by examining fundamental physical processes of …