Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Civil and Environmental Engineering (406)
- Mechanical Engineering (255)
- Electrical and Computer Engineering (236)
- Chemical Engineering (202)
- Petroleum Engineering (96)
-
- Civil Engineering (60)
- Construction Engineering and Management (51)
- Operations Research, Systems Engineering and Industrial Engineering (46)
- Computer Engineering (39)
- Engineering Science and Materials (36)
- Transportation Engineering (35)
- Environmental Engineering (34)
- Physical Sciences and Mathematics (28)
- Other Civil and Environmental Engineering (20)
- Other Engineering (20)
- Hydraulic Engineering (19)
- Materials Science and Engineering (18)
- Other Computer Engineering (16)
- Industrial Engineering (14)
- Life Sciences (12)
- Structural Engineering (12)
- Biomedical Engineering and Bioengineering (11)
- Computer Sciences (11)
- Geotechnical Engineering (11)
- Robotics (11)
- Environmental Sciences (10)
- Other Mechanical Engineering (10)
- Artificial Intelligence and Robotics (8)
- Computer-Aided Engineering and Design (8)
- Keyword
-
- Nanoparticles (14)
- Simulation (12)
- Modeling (11)
- Heat transfer (10)
- Bioremediation (9)
-
- Drilling (9)
- CFD (8)
- Louisiana (8)
- Well control (8)
- Fatigue (7)
- Lean (7)
- MEMS (7)
- Microfluidics (7)
- Oil (7)
- Wettability (7)
- Biodegradation (6)
- Biomass (6)
- Crude oil (6)
- Evacuation (6)
- Film cooling (6)
- Groundwater (6)
- Hurricane (6)
- Image processing (6)
- Marsh (6)
- Model (6)
- Optimization (6)
- Robotics (6)
- Wetlands (6)
- Alumina (5)
- Aquaculture (5)
Articles 751 - 780 of 1307
Full-Text Articles in Engineering
Integrating Lattice Space-Time Codes Of Highest Rank And Multiplexing Over Rayleigh Fading Channels, Vamshi Krishna Samudrala
Integrating Lattice Space-Time Codes Of Highest Rank And Multiplexing Over Rayleigh Fading Channels, Vamshi Krishna Samudrala
LSU Master's Theses
In this thesis, we consider the problem of finding an optimal combination of multiplexing and space-time coding over a MIMO array when a transmitter has a prior knowledge about correlation. Some existing work in this area used multiplexing and space-time coding methods as a technique to achieve capacity over a MIMO wireless channel. In this work, we consider a 2x2 lattice space-time code of highest rank and multiplex it over a MIMO system to improve the bit error rate performance. The main focus of this thesis is to address the problem of switching between spatial multiplexing and space-time coding to …
Enhancement Of Single-Lap Joint Strength Under Tension Using Piezoelectric Actuation, Ryan Michael Meyer
Enhancement Of Single-Lap Joint Strength Under Tension Using Piezoelectric Actuation, Ryan Michael Meyer
LSU Master's Theses
Composite adhesively bonded joint structures have seen increased use over conventional riveted due to their ease of manufacturing and quality strength-to-weight ratios. However, adhesively bonded joints lack the rigidity and failure strength of riveted assemblies, due to high stress concentrations which develop in the adhesive layer, which makes them prone to undesirable deformation and failure. Piezoelectric materials feature the ability to produce mechanical strain when subjected to an applied voltage and vice-versa. Therefore, it is proposed to use piezoelectric actuators to transmit counterbalancing forces to increase the rigidity and strength of composite joints. Existing studies have been limited in that …
An Operational Policy For A Single Vendor Multi Buyer Integrated Inventory Supply Chain System Considering Shipping Time, Chiranjit Saha
An Operational Policy For A Single Vendor Multi Buyer Integrated Inventory Supply Chain System Considering Shipping Time, Chiranjit Saha
LSU Master's Theses
Since its introduction, the concept of integrated inventory supply chain has received a considerable amount of attention. The majority of studies in the last three decades revealed an increase in holding cost as product moves further down the chain or up the chain. A recent study Hoque (2008) considered vendor’s setup cost and inventory holding cost. Some research also considered fixed transportation cost, which is unrealistic. This study focuses on a single-vendor, multi-buyer scenario and presents three models. First, two models illustrate the transferring of equally-sized batches. Then, a third model considers the transferring of unequally-sized batches in a lot. …
Factors Affecting The Interface Shear Strength Of Pavement Layers, Nachiketa Bharat Patel
Factors Affecting The Interface Shear Strength Of Pavement Layers, Nachiketa Bharat Patel
LSU Master's Theses
Flexible pavement structures are built in layers with a certain degree of bonding at the interface, which is affected by several factors which could be either material related, or construction related. The tack coat material type, residual application rate, tack coat coverage, and pavement surface type are attributed as material related factors. On the other hand, cleanliness, moisture, and vertical confinement pressure could be classified as construction related factors. The objective of this study was to quantify the effects of these factors on the pavement interface bonding in terms of interface shear strength. Five types of tack coats, four of …
An Experimental Study Of Surfactant Enhanced Waterflooding, Paulina Metili Mwangi
An Experimental Study Of Surfactant Enhanced Waterflooding, Paulina Metili Mwangi
LSU Master's Theses
Surfactants have a variety of applications in the petroleum industry due to their remarkable ability to lower the oil-water interfacial tension and alter wettability. However, surfactant adsorption on rock surfaces has severely crippled this means of improving oil recovery due to the high cost associated with the large quantities of surfactant needed. A previous experimental study by Ayirala (2002) reported the development of mixed wettability using a nonionic surfactant. At this mixed-wet state he was able to recover about 94% of the original oil in place. The underlying motivation of this study was to achieve such high recoveries without using …
A Study Of Hough Transform For Weld Extraction, Rakesh Gunaseelan
A Study Of Hough Transform For Weld Extraction, Rakesh Gunaseelan
LSU Master's Theses
The process of joining metals is called welding. At times, selecting a poor quality material or improper usage of welding technologies may cause defects in welded joints. Some of these welded joints have to be tested nondestructively, because their failure can cause lot of damage, for instance in power plants. Radiography is a very common method for non-destructive testing of welds. It is done by certified weld inspectors who have knowledge about weld flaws, looking at the radiograph of the welded joint with naked eye. The judgment of the weld inspector can be biased; subjective, because it is dependent on …
Caged Morpholino Oligonucleotide For Control Of Gene Expression In Zebrafish, Chad Michael Jarreau
Caged Morpholino Oligonucleotide For Control Of Gene Expression In Zebrafish, Chad Michael Jarreau
LSU Master's Theses
To control gene expression in vivo with spatial and temporal precision remains a significant hurdle in laboratory studies of development as well as clinical genetic therapies. Here we demonstrate such control over gene expression by use of photochemistry to reversibly inactivate the hybridization of a nucleic acid analog used for specific protein knockdown. A morpholino oligonucleotide, commonly used for knockdown of protein expression in developmental studies, was “caged” using carbodiimide conjugate chemistry which yielded photocleavable adducts that can be removed with light exposure. Photochemical inactivation approaches to produce caged molecules have been used to control the spatiotemporal activity of biomolecules …
Parameterization Of Microwave Assisted Oil Extraction And Its Transesterification To Biodiesel, Akanksha V. Kanitkar
Parameterization Of Microwave Assisted Oil Extraction And Its Transesterification To Biodiesel, Akanksha V. Kanitkar
LSU Master's Theses
Currently, a majority of the world’s energy needs are met through use of fossil fuels, petroleum, coal and natural gas. The depletion of petroleum reserves, rising and extremely volatile crude oil prices, and environmental concerns have led to search for renewable and environmentally friendly fuels. The ultimate goal of this research was to develop, test and optimize a batch microwave system using traditional and alternate non-food feedstocks. Microwave assisted extraction (MAE) of oil from conventional feedstocks (soybeans and rice bran) and an alternative feedstock (Chinese tallow tree (CTT) seeds) was carried out. The study concluded that MAE of oil is …
Empirically Evaluating And Developing Alarm Rate Standards For Liquid Pipeline Control Room Operators, Glen David Uhack Ii
Empirically Evaluating And Developing Alarm Rate Standards For Liquid Pipeline Control Room Operators, Glen David Uhack Ii
LSU Master's Theses
The liquid and gas pipeline community has recently been faced with the challenge of new governmental regulations set forth by congress which are being implemented by PHMSA (an arm of the DOT). These new governmental regulations need to understand the role of the human in the loop as part of alarm management systems. To investigate alarm rate standards a repeated measures design was developed that included a series of ten (10) simulated liquid pipeline operator scenarios utilizing high fidelity liquid pipeline simulation software (Stoner Pipeline Simulator). A total of 39 participants volunteered for this study. Participants completed two subsets of …
Quantification Of Energy Intake Using Food Image Analysis, Sertan Kaya
Quantification Of Energy Intake Using Food Image Analysis, Sertan Kaya
LSU Master's Theses
Obtaining real-time and accurate estimates of energy intake while people reside in their natural environment is technically and methodologically challenging. The goal of this project is to estimate energy intake accurately in real-time and free-living conditions. In this study, we propose a computer vision based system to estimate energy intake based on food pictures taken and emailed by subjects participating in the experiment. The system introduces a reference card inclusion procedure, which is used for geometric and photometric corrections. Image classification and segmentation methods are also incorporated into the system to have fully-automated decision making.
Thermal Conductivity And Its Effects On The Performance Of Pcc Pavements In Mepdg, Upender Kodide
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 …
Estimated Impact Of Left Lane Truck Restriction On Louisiana Highway Pavement Using Mepdg, Mini Radhakrishnan
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 …
Processor Design Space Exploration And Performance Prediction, Balachandran Ramadass
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
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 …
Dynamics Of Vortical Structures In A Low-Blowing-Ratio Pulsed Transverse Jet, Clementine Vezier
Dynamics Of Vortical Structures In A Low-Blowing-Ratio Pulsed Transverse Jet, Clementine Vezier
LSU Master's Theses
Large Eddy Simulation is used to study the interaction of a 35° inclined jet into a crossflow. Steady state cases, with a BR ranging from 0.150 to 1.2, are firstly examined to understand the dynamics of the flow field. Iso-surface of Laplacian of the pressure, vorticity contour and velocity fields highlight the presence of four main vortical structures: shear layer vortices, horse-shoes vortices, wake vortices and CRVP. Qualitative comparisons are performed between simulations and experiments. The dynamics of the flow field is next characterized by pulsing the jet. The studied pulsed cases have same low BR and duty cycle respectively …
Dynamical Investigation Of A Manned Capsule/Tether Re-Entry System, Jeffrey Alan Kornuta
Dynamical Investigation Of A Manned Capsule/Tether Re-Entry System, Jeffrey Alan Kornuta
LSU Master's Theses
The use of tethers in space has an exciting promise in future astronautical applications, with the possibility of providing more sophisticated functionality to satellites and spacecraft. Some of these applications include adjoining satellites, creating microgravity environments, generating power, and transferring momentum between spacecraft. The focus of this project is to investigate the possible reduction in convective heat flux and temperatures on a manned capsule as a result of re-entry with an attached momentum exchange tether, including how various tether parameters affect these results. Using a “bottom-up” approach by modeling the system as a series of lumped masses and rigid rods …
Enhancing Reductive Dechlorination Of Chlorinated Ethenes And Ethanes In A Natural Treatment System, Caroline Burda
Enhancing Reductive Dechlorination Of Chlorinated Ethenes And Ethanes In A Natural Treatment System, Caroline Burda
LSU Master's Theses
Chlorinated solvent contamination continues to plague sites around the world. In many cases, lower chlorinated daughter products build up and remain in ground waters and soils. A Bio-Filter/Phytobed (BFP) system has been developed to replace a traditional pump and treat technology currently operating at the ReSolve Superfund site in North Dartmouth, MA. Pilot scale testing at the facility displayed a significant acclimation period prior to microbial dechlorination, as well as delayed degradation of chlorinated ethanes. Microcosm studies suggest that acidic conditions, possibly created by the peat mixture used to construct the bio-filter, inhibited bacterial growth. The neutralization of trench pH …
Advanced Microwave Technology For Biodiesel Feedstock Processing, Beatrice G. Terigar
Advanced Microwave Technology For Biodiesel Feedstock Processing, Beatrice G. Terigar
LSU Master's Theses
The goal of this work was to assist in overcoming the most important bottlenecks in the biodiesel production chain: to improve the biodiesel production process (oil extraction and esterification) using advanced microwave technologies from traditional and alternative feedstock; and identify the important characteristics of an alternative, high oil yield crop (TT). Dielectric properties of two feedstocks, soybean and rice bran were measured in presence of several solvents at different ratios, temperature and frequency. Results indicated that dielectric properties are ratio, temperature, frequency and solvent type dependent. Quasi-linear relationship using second order logarithmic transformation of the data provided a reliable estimator …
Laboratory Characterization Of Geogrid-Reinforced Unbound Granular Material For Use In Flexible Pavement Structures, Gael Souci
LSU Master's Theses
This thesis documents and summarizes research and background information carried on geogrid reinforced base course in pavement design. Research was experimental carried through Repeated Load Triaxial (RLT) tests at the Louisiana Transportation Research Center. The experimental tests were performed to observe the benefit of the geogrid as well as to differentiate between geogrid location, geometry and tensile modulus of the various geogrid. Experiments were also carried to further describe the Shakedown Theory and its use for characterization of base course materials. The experimental results showed that there was a benefit in placing the geogrid within the aggregate specimen. There were …
Third Order Cmos Decimator Design For Sigma Delta Modulators, Hemalatha Mekala
Third Order Cmos Decimator Design For Sigma Delta Modulators, Hemalatha Mekala
LSU Master's Theses
A third order Cascaded Integrated Comb (CIC) filter has been designed in 0.5μm n-well CMOS process to interface with a second order oversampling sigma-delta ADC modulator. The modulator was designed earlier in 0.5μm technology. The CIC filter is designed to operate with 0 to 5V supply voltages. The modulator is operated with ±2.5V supply voltage and a fixed oversampling ratio of 64. The CIC filter designed includes integrator, differentiator blocks and a dedicated clock divider circuit, which divides the input clock by 64. The CIC filter is designed to work with an ADC that operates at a maximum oversampling clock …
Thermomechanical Modeling And Optimization Of Friction Stir Welding, Manthan Malde
Thermomechanical Modeling And Optimization Of Friction Stir Welding, Manthan Malde
LSU Master's Theses
This thesis research implemented an existing thermomechanical model of friction stir welding process, and studied the surrogate model-based optimization approach to obtain optimal process parameters for the modeled friction stir welding process. As an initial step, the thermomechanical model developed by Zhu and Chao for friction stir welding of 304L stainless steel was replicated using ANSYS. The developed model was then used to conduct parametric studies to understand the effect of various input parameters like total rate of heat input, welding speed and clamping location on temperature distribution and residual stress in the workpiece. With the data from the simulated …
Gas Transfer In Air-Lifts Used To Recirculate Aquaculture Systems, Ryan Anthony Hearn
Gas Transfer In Air-Lifts Used To Recirculate Aquaculture Systems, Ryan Anthony Hearn
LSU Master's Theses
The following studies were conducted to determine hydraulic, aeration, and degasification characteristics associated with various air-lift pumps. The first study presented data on a 20.3 cm air-lift used to support adult Yellowtail broodstock (Seriola lalandi) in an oligotrophic warmwater marine RAS (recirculating aquaculture system). Empirical relationships were used to estimate actual oxygen and carbon dioxide mass transfer rates (AOTR & ACTR) as the inlet oxygen or carbon dioxide concentrations were perturbed under lift heights of 30.5, 38.1, and 45.7 cm. Transfer rates, kg of constituent per day, were found to be dependent on air injection depth and volume, aqueous gas …
Neck Muscles Activity And Upper Body Extremity Angles In Dynamic Overhead Lifting, Mohamed Wassim Mokrani
Neck Muscles Activity And Upper Body Extremity Angles In Dynamic Overhead Lifting, Mohamed Wassim Mokrani
LSU Master's Theses
Injuries of the neck and shoulders are common among workers who perform overhead tasks. In order to develop an injury-free working environment with regards to occupational musculoskeletal stress, it is pivotal to understand the pathophysiology of mechanical stress on the musculoskeletal system. The objective of this research was to study the effect of overhead lifting on the sternocleidomastoid and upper Trapezius muscles. Upper body joint angles were also analyzed using APAS during the overhead lifting. This study was conducted using two devices. The set of equipment incorporates an electromyography device, and the APAS. Two electrodes were placed at the muscle …
Prioritization Of Safety Countermeasures For The State Of Louisiana Using Fuzzy Inference Systems, Meisam Akbarzadeh
Prioritization Of Safety Countermeasures For The State Of Louisiana Using Fuzzy Inference Systems, Meisam Akbarzadeh
LSU Master's Theses
In this study a fuzzy inference system is proposed for prioritization of countermeasures aimed at improving safety in the state of Louisiana. Countermeasures are prioritized based on their collective performance on cost, expected crash reduction and the severity of the problem they address. These three decision parameters can have six permutations in terms of their relative importance in decision making. In order to make the prioritization procedure handier for decision makers, the inference system is capable of being run under all six possible cases. Current safety standards influence the importance attached to crash reduction performance and severity of the problem …
A Simulation-Based Evaluation Of Alternative Initial Responses To Gas Kicks During Managed Pressure Drilling Operations, Majid Davoudi
A Simulation-Based Evaluation Of Alternative Initial Responses To Gas Kicks During Managed Pressure Drilling Operations, Majid Davoudi
LSU Master's Theses
Managed pressure drilling (MPD) is an adaptation of conventional drilling that has been developed to manage and control subsurface pressures in the well in order to minimize specific drilling problems. The constant bottom hole pressure approach (CBHP) is a versatile method of MPD, where a closed annulus allows initial responses to kicks other than simply shutting in the well. The objective of this research was to identify and evaluate the best initial response to gas kicks taken during drilling as a basis for developing reliable well control procedures for CBHP operations. Nine non-circulating and circulating responses (NCRs and CRs) were …
Assessment Of Target Purity Difference For A Louisiana Sugar Mill, Luz Stella Polanco
Assessment Of Target Purity Difference For A Louisiana Sugar Mill, Luz Stella Polanco
LSU Master's Theses
The main goals of a “raw” sugarcane factory are to have an efficient profitable operation with the required sugar quality and maximum sugar recovery. The loss of sugar to final molasses accounts for 45 to 47% of the total sugar losses. An estimation of the average cost of the manufacturing losses for the 2007 harvest season was approximately $9 million – the sugar lost to the final molasses accounts for approximately 50% of this cost (Salassi, 2008). For final molasses, the “Target Purity” (or equilibrium purity) refers to the minimum level of sucrose that theoretically remains in solution for a …
Poly (D, L-Lactide-Co-Glycolide) And Chitosan Particles For Oral Delivery Of Model Lipophilic Vitamin, Abitha Murugeshu
Poly (D, L-Lactide-Co-Glycolide) And Chitosan Particles For Oral Delivery Of Model Lipophilic Vitamin, Abitha Murugeshu
LSU Master's Theses
Improved oral delivery of vitamins and antioxidants via food, beverages or supplements can be achieved by encapsulation of the bioactive component in biodegradable and biocompatible colloidal and nanoparticle systems. Mucoadhesive chitosan/Poly (D, L-lactide-co-glycolide) particles were investigated as a means to control the release of bioactive compounds such as vitamin E in the gastrointestinal (GI) tract. Chitosan/PLGA particles with entrapped alpha-tocopherol at different initial loadings were synthesized by emulsion evaporation method, compared against PLGA particles in terms of their physical properties, stability, and gastrointestinal release profiles. Chi/PLGA particles of 250 ± 8.9 nm with a zeta potential of 61 ± 3.1 …
Laser Assisted Friction Stir Welding: Finite Volume Method And Metaheuristic Optimization, Shivani Daftardar
Laser Assisted Friction Stir Welding: Finite Volume Method And Metaheuristic Optimization, Shivani Daftardar
LSU Master's Theses
Friction Stir Welding (FSW) is a solid state joining process that uses a non-consumable rotating welding tool to generate frictional heat at the welding location. Large forces are required to produce friction between the welding tool and the work piece which increases the wear rate of the welding tool in welding materials with high melting temperature. Several different approaches have been developed to address this problem. This thesis focuses on a new modification of friction stir welding, called Laser Assisted Friction Stir Welding, a process developed in the last decade. This process uses laser energy to preheat the work piece …
Bilateral Filter In Image Processing, Ming Zhang
Bilateral Filter In Image Processing, Ming Zhang
LSU Master's Theses
The bilateral filter is a nonlinear filter that does spatial averaging without smoothing edges. It has shown to be an effective image denoising technique. It also can be applied to the blocking artifacts reduction. An important issue with the application of the bilateral filter is the selection of the filter parameters, which affect the results significantly. Another research interest of bilateral filter is acceleration of the computation speed. There are three main contributions of this thesis. The first contribution is an empirical study of the optimal bilateral filter parameter selection in image denoising. I propose an extension of the bilateral …
Hearing Assessment Of Forest Loggers, Antonio A. Fonseca
Hearing Assessment Of Forest Loggers, Antonio A. Fonseca
LSU Master's Theses
Forest logging is the process in which trees are cut down for forest management and/or timber harvest. According to OSHA, logging is the most dangerous occupation in the United States. It consistently represents one of the most hazardous industries, with a fatality rate more than 21 times higher than the rate for all workers in the United States. Yet, little research has been performed to determine the long term effect of noise on forest loggers. OSHA regulations state that the maximum permissible hearing in an 8 hour shift should not exceed 90 dB. Occupational noise exposure is recognized as a …