Engineering Commons^™

An Experimental And Theoretical Critique Of Flow Model Accuracy, Shannon Ray Chollett

LSU Master's Theses

In today’s exploration and production environment it is required that engineers must collect and use vast amounts of data for flow model construction and calibra- tion, as well as reservoir estimation and optimization. With modern technology, the data volume can be overwhelming. It is necessary that data monitoring and calibration are highly efficient. It is also essential that physical and mathematical models can be tested in repeatable, inexpensive experiments. The experiments described in this thesis will develop and perform verification of algorithms and can generate prior geomodels, collect and process seismic refraction data, collect and process production data, and calibrate …

Towards The Development Of Biotin Carboxylase Driven Robotic Nanoswimmers, Rachel Yates

LSU Master's Theses

The objective of this research is to take the first step towards demonstrating the use of the enzyme biotin carboxylase (BC) as a biomolecular motor. BC is a homodimeric protein involved in fatty biosynthesis in all organisms. The conjecture is that BC can convert chemical energy into useful mechanical work via its conformation change, which acts as a fin or flexible oar producing nonreciprocal motion. To this end, we fabricate a proof-of-concept biomolecular machine driven by BC molecules, viz., a robotic nanoswimmer. This machine consists of a Janus-type nanosize silica particle, where one hemisphere is coated with an intermediate layer …

Surface-Modified Plga Nanoparticles For Targeted Drug Delivery To Neurons, Jingyan Li

LSU Master's Theses

The blood-brain barrier (BBB), which protects the central nervous system (CNS) from unnecessary substances, is a challenging obstacle in the treatment of CNS disease such as Parkinson’s Disease (PD). Many therapeutic agents such as hydrophilic and macromolecular drugs cannot overcome the BBB. One promising solution is the employment of polymeric nanoparticles (NPs) such as poly (lactic-co-glycolic acid) (PLGA) NPs as drug carrier. Over the past few years, significant breakthroughs have been made in developing suitable poly (lactic-co-glycolic acid) (PLGA) and poly (lactic acid) (PLA) nanoparticles for drug delivery across the BBB. Recent advances on PLGA/PLA NPs enhanced neural delivery of …

Morphology Controlled Coating Of Catalytically Active Gold Structures Within Flow-Focused Millifluidic Reactor, Chelliah V. Navin

LSU Master's Theses

Synthesis of micro/nanomaterials within confined flow-based systems such as microfluidics has always been a promising research. However, the inability to scale up reagent volumes due to geometric constraints and pressure development within the channels at higher flow rates has limited their usage. In recent times, millifluidics has emerged as a useful technique where, apart from the synthesis, the in situ characterization of materials becomes easier. In this study, formation of morphology-controlled gold structures at different time intervals (viz. 1, 5, and 9 h) within a millifluidic chip reactor was investigated using gold chloride and dimercaptosuccinic acid (DMSA) as precursor reagents …

Programming And Healing Temperature Effects On The Efficiency Of Confined Self-Healing Polymers, Yves Quentin Yougoubare

LSU Master's Theses

Shape memory polymers are smart materials capable of fixing a temporary shape and returning to their initial shape in response to an external stimulus. Since the discovery and acknowledgment of their importance in 1960s, shape memory polymers have been the subject of tremendous and continuous attention. In a previous study conducted on a biomimetic shape memory polymer (SMP), the ability of a self-healing composite to heal, and to repair and restore structural-length scale damage using a close-then-heal (CTH) self-healing mechanism was examined and validated. The present study is purposed with investigation of the effects on healing efficiencies of the variation …

Simulations Of The Primary Cement Placement In Annular Geometries During Well Completion Using Computational Fluid Dynamics (Cfd), Muhammad Zulqarnain

LSU Master's Theses

Effective zonal isolation during primary cementing is only possible when drilling mud in the annulus is completely displaced with cement, while the spacers aid in this process. During the displacement process the rheological properties of fluids used and the operating conditions control the motion of different fluids interfaces; desired stable interfacial displacement leads to piston like motion. Computational Fluid Dynamics (CFD) tool with the Volume-of-Fluid (VOF) has been validated against experimental and used to conduct numerical experiments in a virtual well model consisting of 50 ft vertical section of 8.765" x 12.5" annulus having initially mud and this mud is …

Development Of Hydrograph-Based Approach To Modeling Fate And Transport Of Sediment-Borne Bacteria In Lowland Rivers, Bhuban Ghimire

LSU Doctoral Dissertations

Fecal pollution is one of the major factors responsible for water quality impairments of rivers and streams, particularly organic-rich fine-grained lowland streams. While predicting fecal pollution is generally required in the development of water quality restoration plans like Total Maximum Daily Loads, no single model has been widely recognized as an efficient and effective tool for estimating fecal pollution. This dissertation develops a simple yet effective modeling approach, called Hydrograph-based Approach, to bacterial fate and transport modeling in lowland rivers. The new hydrograph-based approach is simple and efficient in terms of its less data requirements as compared with other models. …

Evaluation Of The Thermal Performance And Cost Effectiveness Of Radiant Barrier Thermal Insulation Materials In Residential Construction, Somayeh Asadi

LSU Doctoral Dissertations

Reducing heating and cooling systems loads in buildings is a cost effective way to decrease energy consumption in residential houses. This reduction can be achieved in many ways including proper insulation of the building envelope. In recent years, considerable attention was given to the use of radiant reflective insulating barriers. Over the past years, reflective barrier insulation companies nationwide have experienced significant growth resulting in an industry average growth rate of 26.8%. This significant growth is expected to continue as a result of increased cooling demands and pressure from the energy sector and the economy. Growth is also predicted to …

Effect Of Surfactants And Brine Salinity And Composition On Spreading, Wettability And Flow Behavior In Gas-Condensate Reservoirs, Yu Zheng

LSU Doctoral Dissertations

The well-known condensate blockage problem causes severe impairment of gas productivity as the flowing bottom-hole pressure falls below the dew point in gas-condensate reservoirs. Hence, this study attempts to investigate the concept of modifying the spreading coefficient and wettability using low-cost surfactants in the near wellbore region, to prevent the gas flow problems associated with condensate buildup. This study also examines the effect of brine salinity and composition on wettability, spreading and adhesion in condensate buildup regions, to evaluate the ability of brine salinity/composition for enhanced gas productivity in gas-condensate reservoirs. In this study, experiments were performed at both ambient …

Low Temperature Carbon Material Deposition With Photo-Enhanced Chemical Vapor Deposition, Kyungnam Kang

LSU Doctoral Dissertations

Photo-enhanced chemical vapor deposition (CVD) technique is investigated here for low temperature deposition of carbon nanotubes (CNTs) and hexagonal diamond. Most current deposition methods require high substrate temperature. Photo-enhanced CVD utilizes light energy to dissociate carbon containing precursor molecules and hence has a potential for low temperature deposition. CCl4, having a high absorption coefficient compared to other commonly employed hydrocarbons in the UV emission spectrum from a Xe arc lamp, is selected as a carbon precursor in this work. Extensive experimentation conducted by varying Al/Ni/Al catalyst layer thicknesses on SiO2 coated Si substrates, substrate annealing temperature in the range 350 …

Global And Local Performance Of Prestressed Girder Bridges With Positive Moment Continuity Detail, Tanvir Hossain

LSU Doctoral Dissertations

Global as well as local behavior of prestressed girder bridges made continuous by adding continuity diaphragms with a recently proposed positive moment continuity detail were investigated in this study. The focus of the investigation is on the positive moment caused by temperature gradients, time dependent effects such as creep and shrinkage, and some live load positions, and on the force transfer mechanisms through the diaphragm. The study utilized different approaches including analytical models for temperature evaluations and finite element models for structural assessments. Field data from a bridge using the new detail were used to validate the developed models. The …

Synthesis And Characterization Of Geopolymers For Infrastructural Applications, Jian He

LSU Doctoral Dissertations

In this study, the synthesis process, composition, and microstructure as well as mechanical properties of geopolymers generated by 3 different kinds of raw materials (i.e., metakaolin, mixture of red mud and fly ash, mixture of red mud and rice husk ash) was explored. For geopolymers from identical raw materials, variable parameters involved in the synthesis were examined to investigate the extent and degree of geopolymerization. Uniaxial compression testing was used to examine the mechanical properties (i.e. compressive strength, stiffness, and failure strain). Then the composition and microstructure were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) as well …

An Experimental Investigation Of The Role Of Small Hydrocarbons And Combustion-Generated Nanoparticles On The Formation And Growth Reactions Of Polycyclic Aromatic Hydrocarbons During The Pyrolysis Of A Model-Fuel And Hydrocarbon Gases, Nimesh Bharat Poddar

LSU Doctoral Dissertations

Polycyclic aromatic hydrocarbons (PAH) are an important class of environmental pollutants formed during fuel combustion or pyrolysis. Therefore, an experimental study has been undertaken to better understand the formation and growth pathways of PAH.

To investigate the efficacy of C₃ species as PAH growth agents in the context of solid fuels, pyrolysis experiments have been performed in an isothermal quartz flow reactor in the temperature range of 700–1000 °C and a fixed residence time of 0.3 s. Experiments are performed with the C₃ hydrocarbon, propyne; with catechol (ortho-dihydroxybenzene), a model-fuel representative of aromatic moieties in coal …

Turbine Blade Internal Cooling: Trailing Edge, Coolant-Passage Entry, Bend Effect And Improvement In Thermal Performance, Krishnendu Saha

LSU Doctoral Dissertations

Efficient cooling of gas turbine blade is imperative for safe operation of the gas turbine engine at high temperatures. In the present work, two converging lattice structures suitable for trailing edge applications are tested and their performance is compared with a conventional pin-fin configuration. Another constant cross section lattice structure is tested to see the cooling efficiency of lattice channels with different number of sub-channels. Converging lattice structures show higher heat transfer enhancement and comparable or higher thermal performance than traditional pin-fin cooling used in gas turbine trailing edge. The highest pressure drop incurred in a multi-pass channel is at …

An Intelligent Computational Approach To The Optimization Of Inventory Policies For Single Company, Qinglin Duan

LSU Master's Theses

This study develops and tests a computational approach for determining optimal inventory policies for single company. The computational approach generally comprises of two major components: a meta-heuristic optimizer and an event-driven inventory evaluation module. Meta-heuristic is a powerful search technique, under the intelligent computational paradigm. The approach is capable of determining optimal inventory policy under various demand patterns regardless their distribution for a variety of inventory items. Two prototypes of perishability are considered: (1) sudden deaths due to disasters and (2) outdating due to expirations. Since every theoretical model is specially designed for a certain type of inventory problem while …

Energetic Nanoparticles As Fuel Additives For Enhanced Performance In Propulsion Systems, Srinibas Karmakar

LSU Doctoral Dissertations

Biofuels are currently being explored as a carbon-neutral fuel alternative to petroleum-based fuels. However, biofuels such as ethanol has lower energy density (~27MJ/kg) relative to petroleum fuels (~ 45 MJ/kg). Adding high-energy density particles (such as boron with heating value of ~ 58.5 MJ/kg) to biofuels can generate fuel slurry with higher energy density than the base fuel, and represents a potential strategy toward making biofuels more viable. However, the combustion of boron is inhibited (specifically, the ignition is delayed) by the initial presence of an oxide layer, and its high evaporation and boiling temperatures. The present study investigates the …

Measurement Of Interfacial Tension In Hydrocarbon/Water/Dispersant Systems At Deepwater Conditions, Mohamed Abdelrahim

LSU Master's Theses

The events of the Deepwater Horizon oil spill in the Gulf of Mexico were associated with great water depths that made it difficult to understand the behavior of the spilled oil as it came in contact with the seawater. The remedial subsea application of chemical dispersants draws interest to evaluate the interfacial interactions between the oil and water at such great water depths. Most importantly, a quantification of the interfacial tension (IFT) between the spilled oil and seawater at deepwater conditions can provide insight into the effectiveness of the chemical dispersion of spilled oil. In this study, Macondo crude oil …

Stability Problems In Constrained Pendulum Systems And Time-Delayed Systems, Prashanth Ramachandran

LSU Doctoral Dissertations

In this dissertation, we study the boundary of stability of a class of linear mechanical systems as a function of a parameter. We consider two different systems under this class: a constrained double pendulum connected by a rigid rod and a state-feedback-controlled mechanical system with time delay. In the first system, the destabilizing parameter is the distance between the supports of the two pendulums. In the second system, the destabilizing parameter is the time delay. In the constrained double pendulum system, linear perturbation analysis is used to determine the natural frequency of the system. Our analysis reveals a zone of …

Computer Simulations Of Faceted Nanoparticles And Carbon Nanotubes In Liquid Crystals, Shivkumar Shankar Bale

LSU Doctoral Dissertations

The purpose of this research is to investigate the use of liquid crystals (LCs) to manipulate and organize faceted nanoparticles and carbon nanotubes (CNTs). Computer simulations at different levels of detail are used to study these systems. Results from this project will be relevant for potential applications of these systems in displays, nanoscale electronics, electro-optical switches, and in the development of composites with unique mechanical, thermal and/or electronic properties. In this research, two independent but directly related projects were carried out. In the first part of the research, we investigated the torque that develops when faceted nanoparticles, namely cubes and …

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 …

Multifunctional Carbon/Epoxy Glass Microballons Nanocomposite, Ephraim Fentahun Zegeye

LSU Doctoral Dissertations

Glass microballoons have high strength, low thermal and electrical properties, and provide closed cell porosity to reduce the density of composites. On the other hand, filamentous carbon nanostructures have excellent mechanical, thermal, and electrical properties that make them naturally multifunctional. This work presents a method of developing low-density multifunctional nanocomposites utilizing glass microballoons and carbon nanostructures. Two different approaches are investigated. In the first approach, carbon nanotubes (CNTs) are used as a filler material to fabricate nanocomposites containing glass microballoons (CNT-syntactic foams). The weight percent of CNTs is varied from 0 to 0.8 wt%. In this method, CNTs were grown …

Study On Permanent Magnet Transverse Flux Machine, Oleksandr Dobzhanskyi

LSU Doctoral Dissertations

This dissertation is concentrated mainly on the newest PMTF machine topology proposed and patented by Jacek F. Gieras in March 4, 2010. Such a topology (topology of 2010) is an object of this dissertation. A prototype that was built with 3D Finite Element Method (FEM) modeling of PMTF generator proves that the generator that was built on the basis of topology of 2010 has several significant disadvantages among which the greatest impact have high leakage flux losses. Applying FEM modeling, various steps to improve machine performance have been undertaken. Results obtained from modeling show, that keeping the same diameter and …

Numerical Study Of Downhole Heat Exchanger Concept In Geothermal Energy Extraction From Saturated And Fractured Reservoirs, Yin Feng

LSU Doctoral Dissertations

Geothermal energy has gained a lot of attention recently due to several favorable aspects such as ubiquitously distributed, renewable, low emission resources while leveraging the advances in the associated technologies such as directional drilling and low enthalpy power generation plant. However, there are still many challenges such as the high initial capital cost of drilling and surface facilities, environmental risk of seismicity due to the induced disequilibrium in the formation, and sustainability of project over designed operational life. Traditional downhole heat exchangers (DHE) could potentially reduce the capital cost and the risk of seismicity, but they are unable to maintain …

Microfabrication Of Conductive Polymer Nanocomposite For Sensor Applications, Chaoxuan Liu

LSU Doctoral Dissertations

This dissertation developed novel microfabrication techniques of conductive polymer nanocomposite and utilized this material as a functional element for various physical sensor applications. Microstructures of nanocomposite were realized through novel microcontact printing and laser ablation assisted micropatterning processes. Prototype devices including large-strain strain sensor and highly-sensitive pressure sensor were demonstrated showing distinct advantages over existing technologies. The polymer nanocomposite used in this work comprised elastomer poly(dimexylsiloxane) (PDMS) as polymer matrix and multi-walled carbon nananotubes (MWCNTs) as a conductive nanofiller. To achieve uniform distribution of carbon nanotubes within the polymer, an optimized dispersion process was developed, featuring a strong organic solvent—chloroform, …

A Thermodynamic Framework For The Modeling And Optimization Of Crystallization Processes, David John Widenski

LSU Doctoral Dissertations

Crystallization is a widely used chemical engineering separation unit operation process. Since this technique can produce high purity products it is used for the industrial production of many chemical compounds, such as pharmaceuticals, agrochemicals, and fine chemicals. The production of these products is a multi-million dollar industry. Any methods to improve the production of these products would be highly valued. Thus, the main objective of this work is to target model-based optimal strategies for crystallization operations specifically targeting crystal size and crystal size distribution (CSD). In particular, take the knowledge gained and translate it into an economically and practically feasible …

Thermal Field Investigations And Applications To Integral Abutment Bridges With Frp Panels, Bo Kong

LSU Doctoral Dissertations

Expansion joints are often considered as one of the most vulnerable elements affecting the sustainability of traditional jointed bridges. Over the past several decades, a new type of integral abutment bridge (IAB) has been proposed, where the joints are eliminated at the abutments and/or along the length of the bridges. Although with wide acceptances, the IABs have not been largely applied in practice. Many arguments are unsettled and there are no national design guidelines currently. Among all, the thermal behavior is one of the most concerned issues, and that, to a large extent, limits the maximum length of IABs that …

Thermal Stress Analysis Of Jointed Plain Concrete Pavements Containing Fly Ash And Slag, Yoonseok Chung

LSU Doctoral Dissertations

With the current demand for Portland cement concrete (PCC) sustainability, supplementary cementitious materials (SCMs) are used in concrete mixtures. The SCMs positively impact the environmental and economic aspects of concrete mixtures and improve the mixture properties in both fresh and hardened concrete. In this research, one control and twenty-four ternary mixtures, with various combinations of fly ashes (Class C and F), slags (Grade 100 and 120), and Portland cement were fabricated. The thermal properties (coefficient of thermal expansion (CTE), thermal conductivity, and heat capacity) and mechanical properties of the selected ternary mixtures were measured at various ages. Temperature gradients were …

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 …

Applications Of Cfd Simulations On Microfluidic Systems For Nanoparticle Synthesis, Yuehao Li

LSU Master's Theses

Microfluidics has been extensively investigated as a unique platform to synthesize nanoparticles with desired properties, e.g., size and morphology. Compared to the conventional batch reactors, wet-chemical synthesis using continuous flow microfluidics provides better control over addition of reagents, heat and mass transfer, and reproducibility. Recently, millifluidics has emerged as an alternative since it offers similar control as microfluidics. With its dimensions scaled up to millimeter size, millifluidics saves fabrication efforts and potentially paves the way for industrial applications. Good designs and manipulations of microfluidic and millifluidic devices rely on solid understanding of fluid dynamics. Fluid flow plays an important role …

Modeling Of Dynamics Of Gyroscopic Systems, Siddharth Sharma

LSU Master's Theses

The amplitude of vibrations of a rotating system operating near or at its critical speed grows without bound. This poses a serious problem for the rotating machinery industry from the perspective of design, maintenance, vibration troubleshooting and stability of the rotating equipments.

In this thesis, we wish to develop an exact method of analysis for the system of a mass-less symmetrical shaft rotating in symmetrical bearings (SSSB) with finite displacement at bearing end. The method so developed is expected to be extended to the SSSB model of a shaft having mass. The stability analysis is performed for both the systems. …