Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons™

Open Access. Powered by Scholars. Published by Universities.®

2013

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 5941 - 5970 of 7289

Full-Text Articles in Engineering

Experimental Fragility Analysis Of Aluminum Storm Panels Subject To Windborne Debris, Taylor C. Alphonso Jan 2013

Experimental Fragility Analysis Of Aluminum Storm Panels Subject To Windborne Debris, Taylor C. Alphonso

LSU Master's Theses

The research presented in this thesis focused on the derivation of experimental fragility curves for windborne debris (WBD) impact risk assessment of building envelope components (BECs) with ductile behavior (in particular, aluminum storm panels) within the performance-based hurricane engineering (PBHE) framework. Using a pneumatic wind cannon, rod-type WBDs were fired at aluminum storm panels to represent real-life WBD impact hazard. The experimental data from testing were used to derive the probability of failure relative to specific damage measures (DMs) versus its corresponding interaction parameter (IP). These experimentally derived probabilities were compared with results that are available in the literature and …

Go to article

Effect Of Surface Roughness On The Efficiency Of Self-Healing Polymers, Ifeanyi Janarus Okoro Jan 2013

Effect Of Surface Roughness On The Efficiency Of Self-Healing Polymers, Ifeanyi Janarus Okoro

LSU Master's Theses

A shape memory polymer (SMP) is a smart material capable of maintaining two distinct shapes depending on its temperature. A SMP is soft at temperatures above its glass transition temperature but hard below it. When copolyester thermoplastic additives are dispersed in a SMP, it becomes a SMP-based particulate composite capable of self-healing at both the molecular level and the structural level. This makes it very desirable for industrial applications. Upon damage to the composite, the surfaces at the damage interface have to come into contact for efficient healing; the shape memory effect, coupled with a confined recovery (healing) process, ensures …

Go to article

Yield Detection For Non-Destructive Testing Using Ultrasonic Signal Processing, Bharath Murali Thekkedath Jan 2013

Yield Detection For Non-Destructive Testing Using Ultrasonic Signal Processing, Bharath Murali Thekkedath

LSU Master's Theses

Structural health monitoring (SHM) is a very important field for many engineering disciplines. SHM deals with the monitoring of material structures periodically for assessing the lifetimes of the structures. There are various techniques for SHM. Non-destructive testing (NDT) is one of the most popular SHM tools to monitor structures. It demonstrates the indispensable advantage of providing structural health assessment without the need of intrusion. In this thesis, a new NDT tool for yield detection using ultrasonic signal processing is investigated. In this work, for the study of yield detection, steel specimen samples have been acquired, which were obtained from the …

Go to article

Discrete Phase Simulations Of Drilled Cuttings Transport Process In Highly Deviated Wells, Doguhan Yilmaz Jan 2013

Discrete Phase Simulations Of Drilled Cuttings Transport Process In Highly Deviated Wells, Doguhan Yilmaz

LSU Master's Theses

Transporting drilled cuttings from the bottomhole to the surface becomes more difficult and problematic in highly deviated wells than in vertical wells. Cuttings tend to settle down on the low side of the annulus typically in the form of a bed which can cause further problems. The height of this bed depends on many parameters such as annular domain geometry, drilling fluid density and rheology, annular flow rate, drill pipe rotation speed, cuttings size, shape, and their density. Prediction of the stationary cuttings bed height with respect to these aforementioned parameters is thus necessary to optimize the range of the …

Go to article

Coastal Plants For Biofuel Production And Coastal Preservation, Chester Charles Malveaux Jan 2013

Coastal Plants For Biofuel Production And Coastal Preservation, Chester Charles Malveaux

LSU Master's Theses

ABSTRACT Sustainable and renewable biofuels as well as coastal preservation are important to the State of Louisiana which is losing its coastline at the rate of up to 100 square kilometers per year. This has important implications for other coastal areas worldwide. By managing water hyacinth in canals and lakes in coastal Louisiana the biomass of this fast growing aquatic plant can reduce coastal erosion by absorbing wave energy, and remediate waste water through bioabsorption of contaminants, while also providing a source of biofuel. This research has shown that coastal vegetation can play a part in lessening the impact of …

Go to article

Catalytic Conversion Of Biomass Derived Syngas To Liquid Fuels Using Fischer-Tropsch Synthesis, Pratibha Sharma Jan 2013

Catalytic Conversion Of Biomass Derived Syngas To Liquid Fuels Using Fischer-Tropsch Synthesis, Pratibha Sharma

LSU Master's Theses

Biomass gasification and subsequent conversion to liquid hydrocarbons using Fischer-Tropsch synthesis is a promising source of energy in today’s scenario when the focus has shifted from conventional fuels to alternate sources of energy. Biomass derived syngas is different from other sources of syngas such as steam reforming of methane followed by water gas shift, in terms of H2/CO ratio. Biomass syngas is usually hydrogen deficient and contains various impurities which need to be removed prior to Fischer-Tropsch Synthesis. Syngas derived from biomass also differs significantly with the different sources of biomass, gasification process and the cleanup conditions it is subjected …

Go to article

Characterization And Verification Of A Closed Loop Wind Tunnel With A Linear Cascade And Upstream Wake Generator, Christopher Foreman Jan 2013

Characterization And Verification Of A Closed Loop Wind Tunnel With A Linear Cascade And Upstream Wake Generator, Christopher Foreman

LSU Master's Theses

A closed loop wind tunnel designed to study film cooling was completed in May 2011 along with a removable wake generating device. The test section featured a three blade, four passage linear cascade utilizing the Air Force Office of Scientific Research L1A low pressure turbine blade. The wake generator is unique because its blades are flat plates with round leading and trailing edges instead of circular rods. In this report, the test section of the wind tunnel is characterized and validated through velocity and pressure measurements in the test section. Hot-wire surveys were used to characterize the velocity and turbulence …

Go to article

Learning And Identification Of Wireless Network Internode Dynamics Using Software Defined Radio, Benjamin Elliott Carroll Jan 2013

Learning And Identification Of Wireless Network Internode Dynamics Using Software Defined Radio, Benjamin Elliott Carroll

LSU Master's Theses

The recently developed paradigm of cognitive radio wireless devices has been developed with the goal of achieving more customizable and efficient spectrum utilization of commonly used wireless frequency bands. The primary focus of such spectrum utilization approaches has been to discern occupancies and vacancies over portions of the wireless spectrum without necessarily identifying how specific radio frequency (RF) devices contribute to the temporal dynamics of these occupancy patterns within the spectrum. The aim of this thesis is to utilize a hidden semi-Markov model (HSMM) statistical analysis to infer the individual occupancy patterns of specific users from wireless RF observation traces. …

Go to article

Investigation Of Best Practices For Maintenance Of Concrete Bridge Railings, Angel Luis Lence Jan 2013

Investigation Of Best Practices For Maintenance Of Concrete Bridge Railings, Angel Luis Lence

LSU Master's Theses

Biodeterioration on concrete surfaces of vertical elements of bridges represents a serious challenge to the highway infrastructure in Louisiana. This investigation aims to document the causes of biodeterioration of concrete surfaces and to document current conventional and state-of-the-art practices implemented to prevent and clean biofilm. A comprehensive literature review of previous research has been carried out in order to determine the cause and mechanisms of the biodeterioration as well as to identify current methods that state DOTs have implemented in order to maintain their bridges and allow them to function in optimal structural and performance conditions. A survey was developed …

Go to article

Blind Ldpc Encoder Identification, Tian Xia Jan 2013

Blind Ldpc Encoder Identification, Tian Xia

LSU Master's Theses

Nowadays, adaptive modulation and coding (AMC) techniques can facilitate flexible strategies subject to dynamic channel quality. The AMC transceivers select the most suitable coding and modulation mechanisms subject to the acquired channel information. Meanwhile, a control channel or a preamble is usually required to synchronously coordinate such changes between transmitters and receivers. On the other hand, low-density parity-check (LDPC) codes become more and more popular in recent years due to their promising capacity-approaching property. The broad range of variations in code rates and codeword lengths for LDPC codes makes them ideal candidates for future AMC transceivers. The blind encoder identification …

Go to article

A Dynamic Feedback-Control Toll Pricing Methodology : A Case Study On Interstate 95 Manged Lanes, Danhong Cheng Jan 2013

A Dynamic Feedback-Control Toll Pricing Methodology : A Case Study On Interstate 95 Manged Lanes, Danhong Cheng

LSU Master's Theses

Recently, congestion pricing emerged as a cost-effective and efficient strategy to mitigate the congestion problem on freeways. This study develops a feedback-control based dynamic toll approach to formulate and solve for optimal tolls. The study compares the performance of the proposed methodology to that of the current strategy deployed on Interstate 95 express lanes. Two objectives are studied: one is to maximize the toll revenue while maintaining a minimum level of service on the managed lanes and the other is to maximize both revenue and throughput on the managed lanes while keeping a minimum level of service. The impact of …

Go to article

Controversy Trend Detection In Social Media, Rajshekhar Vishwanath Chimmalgi Jan 2013

Controversy Trend Detection In Social Media, Rajshekhar Vishwanath Chimmalgi

LSU Master's Theses

In this research, we focus on the early prediction of whether topics are likely to generate significant controversy (in the form of social media such as comments, blogs, etc.). Controversy trend detection is important to companies, governments, national security agencies, and marketing groups because it can be used to identify which issues the public is having problems with and develop strategies to remedy them. For example, companies can monitor their press release to find out how the public is reacting and to decide if any additional public relations action is required, social media moderators can moderate discussions if the discussions …

Go to article

Using Grounded Theory To Develop A Framework For Software Testing Best Practice In A Telecommunications Company, David Hendrick Jan 2013

Using Grounded Theory To Develop A Framework For Software Testing Best Practice In A Telecommunications Company, David Hendrick

Dissertations

Software testing is a key part of the software development process, irrespective of the development methodology being followed. Estimates suggest that testing can account for more than 50% of the cost of a software development project. However, the cost of inadequate testing or verifying software can be far greater; this can result in losses that could total more than 10% of an organisation’s turnover. It is clear that software testing is essential; but while many companies implement different forms of testing, there is often no structure or best practice followed to this testing. There appears to be a gap in …

Go to article

Time-Variant Performance Assessment And Improvement Of Existing Bridges, Miao Xia Jan 2013

Time-Variant Performance Assessment And Improvement Of Existing Bridges, Miao Xia

LSU Doctoral Dissertations

The serviceability and safety of buildings and bridges are expected to be maintained within a reasonable safety level throughout their lifetimes. However, the increase of the applied loads and degradation of structural performances reduce the safety of these structures over time. Therefore, the performance assessment of existing bridges with reliability theories is a worldwide problem in civil infrastructure systems. Theoretically, the bridge reliability, usually expressed by a reliability index, is quantified by comparing the structural capacity (R) with the load effects (Q), using the predefined limit state functions. A limit state function is a mathematical description of a boundary between …

Go to article

Doping Of Metal Organic Framework (Uio) And For N02 Adsorption At Ambient Conditions, Amani M. Ebrahim Jan 2013

Doping Of Metal Organic Framework (Uio) And For N02 Adsorption At Ambient Conditions, Amani M. Ebrahim

Dissertations and Theses

Pollution issues and environmental concerns have led to the development of various air purification technologies. Nitrogen dioxide NO2 is one of the toxic gases in the atmosphere that is corrosive; it causes severe damage to materials, even at low concentrations. Research on the adsorption of this gas at atmospheric pressure and ambient temperatures is uncommon because of limited industrial applications. The thermal stability and microporous nature of Zirconium-based Metal Organic Framework (Zr-MOF) UiO-66 and UiO-67 make them good candidates for metal or amine decoration. The objective of this work was to investigate the effect of metal or amine doping (direct …

Go to article

Automated Semantic Content Extraction From Images, Mahdi Arab Khazaeli Jan 2013

Automated Semantic Content Extraction From Images, Mahdi Arab Khazaeli

LSU Doctoral Dissertations

In this study, an automatic semantic segmentation and object recognition methodology is implemented which bridges the semantic gap between low level features of image content and high level conceptual meaning. Semantically understanding an image is essential in modeling autonomous robots, targeting customers in marketing or reverse engineering of building information modeling in the construction industry. To achieve an understanding of a room from a single image we proposed a new object recognition framework which has four major components: segmentation, scene detection, conceptual cueing and object recognition. The new segmentation methodology developed in this research extends Felzenswalb's cost function to include …

Go to article

Modeling And Simulation Of Surface Profile Forming Process Of Microlenses And Their Application In Optical Interconnection Devices, Zhengyu Miao Jan 2013

Modeling And Simulation Of Surface Profile Forming Process Of Microlenses And Their Application In Optical Interconnection Devices, Zhengyu Miao

LSU Doctoral Dissertations

Free space micro-optical systems require to integrate microlens array, micromirrors, optical waveguides, beam splitter, etc. on a single substrate. Out-of-plane microlens array fabricated by direct lithography provides pre-alignment during mask fabrication stage and has the advantage of mass manufacturing at low cost. However, this technology requires precise control of the surface profile of microlenses, which is a major technical challenge. The quality control of the surface profile of microlenses limits their applications. In this dissertation, the surface forming process of the out-of-plane microlenses in UV-lithography fabrication was modeled and simulated using a simplified cellular automata model. The microlens array was …

Go to article

Multi-Scale Modeling Of Inertial Flows Through Propped Fractures, Ali Takbiri Borujeni Jan 2013

Multi-Scale Modeling Of Inertial Flows Through Propped Fractures, Ali Takbiri Borujeni

LSU Doctoral Dissertations

Non-Darcy flows are expected to be ubiquitous in near wellbore regions, completions, and in hydraulic fractures of high productivity gas wells. Further, the prevailing dynamic effective stress in the near wellbore region is expected to be an influencing factor for the completion conductivity and non-Darcy flow behavior in it. In other words, the properties (fracture permeability and β-factor) can vary with the time and location in the reservoir (especially in regions close to the wellbore). Using constant values based on empirical correlations for reservoirs/completions properties can lead to erroneous cumulative productivity predictions. With the recent advances in the imaging technology, …

Go to article

Modeling And Simulation Study Of A Dynamic Gas Turbine System In A Virtual Test Bed Environment, Eshwarprasad Thirunavukarasu Jan 2013

Modeling And Simulation Study Of A Dynamic Gas Turbine System In A Virtual Test Bed Environment, Eshwarprasad Thirunavukarasu

Theses and Dissertations

Gas Turbine is a complex system and highly non linear in its overall performance. For power generation applications, it is essential to develop a reliable gas turbine model for simulating the impact on electric power generated under various load conditions. This research focuses on development of a dynamic gas turbine model to simulate both single shaft and twin shaft engines. The model is developed on a virtual test bed platform which is an advanced dynamic multidisciplinary simulation environment. The modeling approach starts by developing mathematical models for individual components of gas turbines based on the thermodynamic laws and is coupled …

Go to article

Investigation Of Start Domain Proteins In Human Luteinized Cells And Cos-1 Cells, Bo Shi Jan 2013

Investigation Of Start Domain Proteins In Human Luteinized Cells And Cos-1 Cells, Bo Shi

Theses and Dissertations

After the luteinizing hormone surge of the menstrual cycle, the ovarian follicular granulosa and theca cells terminally differentiate to form the luteal cells of the corpus luteum. During this process known as luteinization, granulosa cells begin to synthesize large quantities of progesterone, a hormone essential for pregnancy. The rate limiting step for the de novo synthesis of pregnenolone (the precursor to progesterone) is the transport of cholesterol from the outer to the inner mitochondrial membrane, a process mediated by STARD1. STARD1 contains a C-terminal lipid binding domain holding one molecule of cholesterol, and an N-terminal domain targeting STARD1 to the …

Go to article

Improving Robustness And Scalability Of Available Ner Systems, Amber Mckenzie Jan 2013

Improving Robustness And Scalability Of Available Ner Systems, Amber Mckenzie

Theses and Dissertations

The focus of this research is to study and develop techniques to adapt existing NER resources to serve the needs of a broad range of organizations without expert NLP manpower. My methods emphasize usability, robustness and scalability of existing NER systems to ensure maximum functionality to a broad range of organizations. Usability is facilitated by ensuring that the methodologies are compatible with any available open-source NER tagger or data set, thus allowing organizations to choose resources that are easy to deploy and maintain and fit their requirements. One way of making use of available tagged data would be to aggregate …

Go to article

A Method For Evaluating Power Generation Concepts Considering The Optimal Concept Of Operations, Tianlei Zhang Jan 2013

A Method For Evaluating Power Generation Concepts Considering The Optimal Concept Of Operations, Tianlei Zhang

Theses and Dissertations

When trying to select an appropriate power generation plant for a micro-grid power distribution system like an electric ship, designers must consider both the physical characteristics (e.g., weight, volume, power ratings) and performance characteristics (e.g., fuel consumption, quality of service) of all the design alternatives. Comparing the design alternatives in terms of the physical characteristics is relatively straightforward, but in terms of performance characteristics each design alternative has to be evaluated within its own optimal performance points to make a fair comparison. However, at present no effective method or software tools exist to enable this evaluation at the earliest design …

Go to article

Modeling Of Sic Power Semiconductor Devices For Switching Converter Applications, Ruiyun Fu Jan 2013

Modeling Of Sic Power Semiconductor Devices For Switching Converter Applications, Ruiyun Fu

Theses and Dissertations

Thanks to recent progress in SiC technology, SiC JFETs, MOSFETs and Schottky diodes are now commercially available from several manufactories such as Cree, GeneSiC and Infineon. SiC devices hold the promise of faster switching speed compared to Si devices, which can lead to superior converter performance, because the converter can operate at higher switching frequencies with acceptable switching losses, so that passive filter size is reduced. However, the ultimate achievable switching speed is determined not only by internal semiconductor device physics, but also by circuit parasitic elements. Therefore, in order to accurately predict switching losses and actual switching waveforms, including …

Go to article

Investigation Of Three-Way (Twc), Lean Nox Trap (Lnt) And Selective Catalytic Reduction (Scr) Catalysts For Control Of Nox Emissions From Lean-Burn Engines, Christopher Dominic Digiulio Jan 2013

Investigation Of Three-Way (Twc), Lean Nox Trap (Lnt) And Selective Catalytic Reduction (Scr) Catalysts For Control Of Nox Emissions From Lean-Burn Engines, Christopher Dominic Digiulio

Theses and Dissertations

Lean-burn gasoline engines are approximately 10% more fuel efficient than conventional, stoichiometric-burn ones. Although relatively modest, if implemented across the entire U.S. automotive fleet, this improvement in fuel economy could have far-reaching implications on the amount of gasoline imported in the country on an annual basis. However, the development of a cost-effective catalytic converter catalyst capable of meeting emission regulations for lean-burn vehicles still represents a major technical challenge. Currently, lean NOX trap (LNT) and selective catalytic reduction (SCR) catalysts are used for this purpose, but both systems suffer from significant drawbacks. For example, LNT catalysts generally require high platinum …

Go to article

Approaches That Will Yield Greater Success When Implementing Self-Administered Electronic Data Capture Ict Systems In The Developing World With An Illiterate Or Semi-Literate Population, Stanley J. Mierzwa, Samir Souidi, Irene Friedland, Sarah A. Littlefield, Lauren L. Katzen, Craig Savel, Deborah Boccio, Saumya Ramarao Jan 2013

Approaches That Will Yield Greater Success When Implementing Self-Administered Electronic Data Capture Ict Systems In The Developing World With An Illiterate Or Semi-Literate Population, Stanley J. Mierzwa, Samir Souidi, Irene Friedland, Sarah A. Littlefield, Lauren L. Katzen, Craig Savel, Deborah Boccio, Saumya Ramarao

Reproductive Health

The Information Technology (IT) Group at the Population Council responded to a need for a technology solution that would help researchers obtain more accurate responses to survey questions that concerned subject matter of a sensitive nature. The IT Group had three goals: (1) to enhance research by obtaining the best data possible, (2) to operate successfully in the local environment and be welcomed by the local populations, and (3) to increase the efficiency and cost-effectiveness of the survey process. This paper outlines approaches to consider when designing and implementing self-administered information and communications technology (ICT) questionnaires in developing countries, and …

Go to article

Investigation Of Nanoparticle Delivery To Cancer Cells By Conjugation With Various Targeting Moieties, Leila Hossein Rashidi Jan 2013

Investigation Of Nanoparticle Delivery To Cancer Cells By Conjugation With Various Targeting Moieties, Leila Hossein Rashidi

Bioengineering Theses - Archive

Recently, mapping and profiling of specific tumor biomarkers characterizing cancer cells, followed by understanding of signal cascades involved in the pathogenesis of tumors (targeted therapy), as well as diagnosis in early stages, have become promising topics in cancer research. Since, the most considerable limitations of conventional therapies and diagnostic modalities are associated with nonspecific targeting; designing intelligent new anti-cancer nanocarries improved by targeting biomolecules could enhance therapeutic efficiencies as well as diagnosis in early stage of cancer. Active targeting which is based on the surface accessibility and the high level of expression of specific cancer antigens has attracted much attention …

Go to article

Effect Of Body Mass Index On The Biomechanical Properties Of Anterior Vaginal Wall Tissue Of Prolapsed Patients, Sandra Gabriela Ochoa Lopez Jan 2013

Effect Of Body Mass Index On The Biomechanical Properties Of Anterior Vaginal Wall Tissue Of Prolapsed Patients, Sandra Gabriela Ochoa Lopez

Bioengineering Theses - Archive

Anterior Vaginal Wall (AVW) prolapse is a bothersome condition that affects thousands of women. Its onset and progression is not well understood but is thought to be multifactorial. Biomechanical properties of AVW tissue from prolapsed patients have been measured in-vitro using excised tissue specimens with great variability found in results, possibly from differences in tissue preparation, setting, preservation time, temperature, hydration, etc. In-vivo test using a BTC-2000TM cutometer-like device has recently been developed that measures the tissue uplift under suction pressure load. In this study, a systematical analysis of biomechanical property measurements from AVW tissues was done, including both in-vitro …

Go to article

Measurement Of Transverse Relaxation Times Of Cerebral Metabolites In Brain Tumors, Akshay Madan Jan 2013

Measurement Of Transverse Relaxation Times Of Cerebral Metabolites In Brain Tumors, Akshay Madan

Bioengineering Theses - Archive

Proton (¹H) magnetic resonance spectroscopy (MRS) provides a non-invasive means of assessing metabolite concentration for a range of biologically important cerebral compounds in vivo. To extract quantitative information, additional data regarding proton spin relaxation phenomena is critical. Transverse relaxation times (T₂) of cellular metabolites depend on the local molecular environment in which they reside. Several neurological diseases alter the molecular environment, which may be reflected in the changes of the T₂ relaxation times. Therefore alterations in T₂ in tumors may provide important information about the local environment and a potential non-invasive diagnostic tool. Thirty-seven adult patients with gliomas and 11 …

Go to article

Microfluidic Chip-Based Fabrication Of Hollow Alginate Microfiber For Enzyme Entrapment And Reaction, Uyen Hoang Thao Pham Jan 2013

Microfluidic Chip-Based Fabrication Of Hollow Alginate Microfiber For Enzyme Entrapment And Reaction, Uyen Hoang Thao Pham

Bioengineering Theses - Archive

This thesis demonstrates a simple process to generate alginate hollow microfibers by using a non-lithographic PDMS microfluidic device. The microfluidic device was fabricated by a novel template method in a wet lab without the support of any conventional lithography techniques. The relationships of the flow rate and the diameter of hollow alginate fibers were characterized. It was found that the outer diameter of the alginate hollow fiber was independent of the flow rate, but the core flow and sheath flow played an important role to control the internal diameter and the wall thickness of the alginate hollow microfiber. At a …

Go to article

Design, Fabrication And Evaluation Of A Novel Microfluidic Based In Vitro Cell Migration Assay, Sai Sirisha Dhavala Jan 2013

Design, Fabrication And Evaluation Of A Novel Microfluidic Based In Vitro Cell Migration Assay, Sai Sirisha Dhavala

Bioengineering Theses - Archive

Microfabrication and microfluidic devices have been recognized as potential platforms for cell-based and drug screening studies. Human glioblastoma multiforme (hGBM) cells migrate inside the central nervous system (CNS) in narrow space constrictions and rarely metastasize through bloodstream. Hence, microfluidic devices consisting of narrow channels are considered as suitable models to study cell migration in vitro. Further the migratory capability of each individual cell could be easily obtained and quantified using such system. This effort presents the design and development of an alternative microfluidic system that provides an integrated array of channels for screening multiple drugs simultaneously. This system is an …

Go to article

First Prev Next Last