The Investigation Of Valve Operators' Torque Production Capabilities And Optimal Handwheel Height, Angle, And Opening Technique,
2013
Louisiana State University and Agricultural and Mechanical College
The Investigation Of Valve Operators' Torque Production Capabilities And Optimal Handwheel Height, Angle, And Opening Technique, Saif K. Al-Qaisi
LSU Doctoral Dissertations
This research consists of two projects concerned with handwheel-valve operations. The objectives of poject-1 were to: (1) introduce an ergonomically-modified valve-wrench and compare it to conventional valve-opening methods, in terms of efficiency (time to open valve), perceived physical exertion (Borg-scale), and muscle loading of shoulder and trunk muscles; and (2) determine whether the torque setting (15 Nm and 30 Nm) of the valve affects the preferred valve-opening method. Four methods were evaluated, including using bare hands (BH), conventional wrench-restricted (CW-R, assumes presence of obstructions), conventional wrench-unrestricted (CW-U, assumes no obstructions), and modified wrench (MW). Electromyography (EMG) activities were measured from …
Optimal Consignment Stocking Policies For A Supply Chain Under Different System Constraints,
2013
Louisiana State University and Agricultural and Mechanical College
Optimal Consignment Stocking Policies For A Supply Chain Under Different System Constraints, Hui Zhi Yi
LSU Doctoral Dissertations
The research aims are to enable the decision maker of an integrated vendor-buyer system under Consignment Stock (CS) policy to make the optimal/sub-optimal production/replenishment decisions when some general and realistic critical factors are considered. In the system, the vendor produces one product at a finite rate and ships the outputs by a number of equal-sized lots within a production cycle. Under a long-term CS agreement, the vendor maintains a certain inventory level at the buyer’s warehouse, and the buyer compensates the vendor only for the consumed products. The holding cost consists of a storage component and a financial component. Moreover, …
Microstructure And Physics-Based Structural Models For Suspended Clay-Exopolymer Flocs,
2013
Louisiana State University and Agricultural and Mechanical College
Microstructure And Physics-Based Structural Models For Suspended Clay-Exopolymer Flocs, Xiaoling Tan
LSU Doctoral Dissertations
Costal or shoreline waters are often characterized by high concentrations of suspended cohesive sediments (or clay) affected by varied organic matters (mostly extracellular polymeric substances or exopolymers), salt, and hydrodynamic disturbance. Resulting from the flocculation-disaggregation between the colloidal clay and exopolymer, the size and structure changes of the cohesive sediments are of key importance for understanding sediment transport processes (i.e., settling, breakage, and survivability) and the geotechnical and geophysical properties of the bottom bed. Because the coastal environment is extremely complicated, with many unpredictable and uncontrollable parameters, current knowledge is still insufficient to predict or fully explain the behavior of …
Resolving Pronominal Anaphora Using Commonsense Knowledge,
2013
Louisiana State University and Agricultural and Mechanical College
Resolving Pronominal Anaphora Using Commonsense Knowledge, Seyedeh Leili Javadpour
LSU Doctoral Dissertations
Coreference resolution is the task of resolving all expressions in a text that refer to the same entity. Such expressions are often used in writing and speech as shortcuts to avoid repetition. The most frequent form of coreference is the anaphor. To resolve anaphora not only grammatical and syntactical strategies are required, but also semantic approaches should be taken into consideration. This dissertation presents a framework for automatically resolving pronominal anaphora by integrating recent findings from the field of linguistics with new semantic features. Commonsense knowledge is the routine knowledge people have of the everyday world. Because such knowledge is …
Geodatabase-Assisted Storm Surge Modeling,
2013
Louisiana State University and Agricultural and Mechanical College
Geodatabase-Assisted Storm Surge Modeling, Sait Ahmet Binselam
LSU Doctoral Dissertations
Tropical cyclone-generated storm surge frequently causes catastrophic damage in communities along the Gulf of Mexico. The prediction of landfalling or hypothetical storm surge magnitudes in U.S. Gulf Coast regions remains problematic, in part, because of the dearth of historic event parameter data, including accurate records of storm surge magnitude (elevation) at locations along the coast from hurricanes. While detailed historical records exist that describe hurricane tracks, these data have rarely been correlated with the resulting storm surge, limiting our ability to make statistical inferences, which are needed to fully understand the vulnerability of the U.S. Gulf Coast to hurricane-induced storm …
Quantification Of The Environmental Impact Of Titanium Dioxide Photocatalytic Pavements For Air Pollution Remediation,
2013
Louisiana State University and Agricultural and Mechanical College
Quantification Of The Environmental Impact Of Titanium Dioxide Photocatalytic Pavements For Air Pollution Remediation, Heather Lee Dylla
LSU Doctoral Dissertations
Photocatalytic concrete pavements are a promising technology for mobile source air pollution remediation, however before widespread application of this technology is realized many unanswered questions remain regarding its overall environmental impact. In response to these questions, the goal of this study was to increase the understanding of the environmental impact of photocatalytic concrete pavement highways. To achieve this goal, the objectives of this study were to (A) construct a model that evaluates the nitrogen oxides (NOx) reduction from photocatalytic pavements, (B) quantify the nitrates released from the photocatalytic degradation of NOx, and (C) identify and characterize pathways for TiO2 nanoparticle …
Automated Semantic Content Extraction From Images,
2013
Louisiana State University and Agricultural and Mechanical College
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 …
Silver Nanoparticles As Drug Delivery Systems,
2013
Louisiana State University and Agricultural and Mechanical College
Silver Nanoparticles As Drug Delivery Systems, Ammar Tahseen Qureshi
LSU Doctoral Dissertations
The goal of this project is to study the potential applications of silver nanoparticles (SNPs) in the medical device and pharmaceutical industries. Bone cements have been used in the orthopedic surgeries for many years to anchor prosthetics while filling up the spaces between the prostheses and bone. Antibiotics are an active component of bone cements but the increasing bacterial resistance to these antibiotics and difficulty of shaping and molding the bone cements increases the need for new antimicrobial biomaterials. Adult stem cell based regenerative therapies have been one of the most widely researched areas of tissue engineering. This is due …
A Metaheuristic-Based Simulation Optimization Framework For Supply Chain Inventory Management Under Uncertainty,
2013
Louisiana State University and Agricultural and Mechanical College
A Metaheuristic-Based Simulation Optimization Framework For Supply Chain Inventory Management Under Uncertainty, Qinglin Duan
LSU Doctoral Dissertations
The need for inventory control models for practical real-world applications is growing with the global expansion of supply chains. The widely used traditional optimization procedures usually require an explicit mathematical model formulated based on some assumptions. The validity of such models and approaches for real world applications depend greatly upon whether the assumptions made match closely with the reality. The use of meta-heuristics, as opposed to a traditional method, does not require such assumptions and has allowed more realistic modeling of the inventory control system and its solution. In this dissertation, a metaheuristic-based simulation optimization framework is developed for supply …
Designing A Cost Effective Microalgae Harvesting Strategy For Biodiesel Production With Electrocoagulation And Dissolved Air Flotation,
2013
Louisiana State University and Agricultural and Mechanical College
Designing A Cost Effective Microalgae Harvesting Strategy For Biodiesel Production With Electrocoagulation And Dissolved Air Flotation, Adam James Dassey
LSU Doctoral Dissertations
Microalgal harvesting strategies for biodiesel production have been a major setback in the industry with high energy estimates of $3400/ton biomass by centrifugation. The present study utilized effective mass and energy balances to reduce these large operating costs. The energy for Stage 1 centrifugation was reduced by 82% when harvesting 28.5% of biomass at 18 L/min as opposed to 95% harvesting at 1 L/min. This strategy was further confirmed using electrocoagulation (EC) with Nannochloris and Dunaliella algae with perforated aluminum and iron electrodes at low (< 6 mg/L) metal ion concentrations. Despite 20% lower harvesting efficiencies, the iron electrodes were more energy and cost efficient with operating costs less than $0.03/L oil when flocculating and settling Nannochloris and Dunaliella cultures. Furthermore, a continuous multistage algae harvester using EC and dissolved air flotation (DAF) for Stage 1 harvesting and centrifugation for Stage 2 dewatering was designed. It was determined throughout the testing that greater EC costs for improved harvesting efficiencies were necessary to offset the large energy requirements of the DAF. The multistage system dewatered a low density (100 mg/L) Nannochloris to 20% solids for a final energy requirement of 1.536 kWh/kg algae ($138/ton). Using the data collected from this research and existing literature, a life cycle analysis was assembled to judge the sustainability of microalgal biofuels in Louisiana. High and low energy estimates for culturing (mixing, CO2, nutrients), harvesting, lipid extraction and energy conversion were compared with the current research. Scaling the EC/DAF system for a full size facility was expected to reduce the harvesting costs to 1.133 kWh/kg algae, resulting as $0.44/L oil for a culture with 20% lipids. Despite this improvement in harvesting costs, the production of algal for the sole purpose of biodiesel was not economically viable. Considering a system with a growth rate of 15 g/m2/day and lipid content of 20%, the energy inputs exceeded the outputs from biodiesel production by 36% under the most ideal conditions. However, incorporating additional revenue through wastewater treatment and biogas production from residual biomass could improve sustainability and profitability of algal biodiesel to an 18.5% energy surplus at its current state.
Scaling Of The Coercive Field In Ferroelectrics At The Nanoscale,
2013
Institute of Crystallography, Russian Academy of Science, Moscow
Scaling Of The Coercive Field In Ferroelectrics At The Nanoscale, R. V. Gaynutdinov, M. Minnekaev, S. Mitko, A. L. Tolstikhina, A. Zenkevich, Stephen Ducharme, Vladimir M. Fridkin
Stephen Ducharme Publications
The scaling of the coercive field in ferroelectric films at the nanoscale is investigated experimentally. The scaling in the films of copolymer vinylidene fluoride and BaTiO3 with thickness equal by the order of value to the critical domain nucleus size 1–10 nm reveals deviation from the well-known Kay–Dunn law. At this thickness region coercive field does not depend on thickness and coincides with Landau–Ginzburg–Devonshire value.
Review Of Electrochemical And Electrodischarge Machining,
2013
University of Nebraska-Lincoln
Review Of Electrochemical And Electrodischarge Machining, Kamlakar P. Rajurkar, M. M. Sundaram, A. P. Malshe
Department of Mechanical and Materials Engineering: Faculty Publications
Electrochemical and electro-discharge machining processes are the two major electro-machining processes with unique capabilities. Electrical Discharge Machining (EDM) and Electrochemical Machining (ECM) offer a better alternative or sometimes the only alternative in generating accurate 3-D complex shaped macro, micro and nano features and components of difficult–to-machine materials. Technological advances reported in electrochemical and electro discharge machining processes, which reflect the state of the art in academic and industrial research and applications, are briefly reviewed in this paper.
Wire Electro-Discharge Machining Of Titanium Alloy,
2013
University of Nebraska-Lincoln
Wire Electro-Discharge Machining Of Titanium Alloy, Farnaz Nourbakhsh, Kamlakar P. Rajurkar, Ajay P. Malshe, Jian Cao
Department of Mechanical and Materials Engineering: Faculty Publications
This paper presents an experimental investigation of wire electro-discharge machining (WEDM) of titanium alloy. The objective is to investigate the effect of seven process parameters including pulse width, servo reference voltage, pulse current, and wire tension on process performance parameters (such as cutting speed, wire rupture and surface integrity). A Taguchi L18 design of experiment (DOE) has been applied. All experiments have been conducted using Charmilles WEDM. It was also found that the cutting speed increases with peak current and pulse interval. Surface roughness was found to increase with pulse width and decrease with pulse interval. The Analysis of Variance …
Selective Detection And Automated Counting Of Fluorescently-Labeled Chrysotile Asbestos Using A Dual-Mode High-Throughput Microscopy (Dm-Htm) Method,
2013
Kookmin University
Selective Detection And Automated Counting Of Fluorescently-Labeled Chrysotile Asbestos Using A Dual-Mode High-Throughput Microscopy (Dm-Htm) Method, Myoung-Ock Cho, Hyo Mi Chang, Donghee Lee, Yeon Gyu Yu, Hwataik Han, Jung Kyung Kim
Department of Mechanical and Materials Engineering: Faculty Publications
Phase contrast microscopy (PCM) is a widely used analytical method for airborne asbestos, but it is unable to distinguish asbestos from non-asbestos fibers and requires time-consuming and laborious manual counting of fibers. Previously, we developed a high-throughput microscopy (HTM) method that could greatly reduce human intervention and analysis time through automated image acquisition and counting of fibers. In this study, we designed a dual-mode HTM (DM-HTM) device for the combined reflection and fluorescence imaging of asbestos, and automated a series of built-in image processing commands of ImageJ software to test its capabilities. We used DksA, a chrysotile-adhesive protein, for selective …
Photovoltaic Device,
2013
Lincoln, NE
Photovoltaic Device, Jinsong Huang, Bin Yang, Yongbo Yuan
Department of Mechanical and Materials Engineering: Faculty Publications
An apparatus includes a substrate; and a photoactive layer disposed on the substrate. The photoactive layer includes an electron acceptor material; an electron donor material; and a material having dipoles.
Elastic–Plastic Analysis And Strength Evaluation Of Adhesive
Joints In Wind Turbine Blades,
2013
University of Nebraska–Lincoln
Elastic–Plastic Analysis And Strength Evaluation Of Adhesive Joints In Wind Turbine Blades, Yi Hua, Ananth Ram Mahanth Kasavajhala, Linxia Gu
Department of Mechanical and Materials Engineering: Faculty Publications
The objective of this paper is to investigate the performance of adhesive joints of carbon/epoxy wind turbine blade subjected to combined bending and tension loadings through finite element method. The influence of adhesive material properties and geometrical details including fillet and imperfections was examined in terms of interlaminar stresses in the adhesive layer. The variation of stress intensity with change in adhesive shear modulus has also been investigated, while contour integral method was used for evaluating the stress intensity factors (SIF) at the imperfection tip. Furthermore, the strength of the joint was assessed through the crack initiation and propagation analysis. …
Solution-Processed Nanoparticle
Super-Float-Gated Organic Field-Effect
Transistor As Un-Cooled Ultraviolet And
Infrared Photon Counter,
2013
University of Nebraska-Lincoln
Solution-Processed Nanoparticle Super-Float-Gated Organic Field-Effect Transistor As Un-Cooled Ultraviolet And Infrared Photon Counter, Yongbo Yuan, Qingfeng Dong, Bin Yang, Fawen Guo, Qi Zhang, Ming Han, Jinsong Huang
Department of Mechanical and Materials Engineering: Faculty Publications
High sensitivity photodetectors in ultraviolet (UV) and infrared (IR) range have broad civilian and military applications. Here we report on an un-cooled solution-processed UV-IR photon counter based on modified organic field-effect transistors. This type of UV detectors have light absorbing zinc oxide nanoparticles (NPs) sandwiched between two gate dielectric layers as a floating gate. The photon-generated charges on the floating gate cause high resistance regions in the transistor channel and tune the source-drain output current. This ‘‘super-float-gating’’ mechanism enables very high sensitivity photodetectors with a minimum detectable ultraviolet light intensity of 2.6 photons/µm2s at room temperature as well …
Analysis Of Electrically-Forced Vibrations Of Piezoelectric Mesa Resonators,
2013
University of Nebraska-Lincoln
Analysis Of Electrically-Forced Vibrations Of Piezoelectric Mesa Resonators, Huijing He, Guo-Quan Nie, Jin-Xi Liu, Jiashi Yang
Department of Mechanical and Materials Engineering: Faculty Publications
We study the electrically forced thickness-shear and thickness-twist vibrations of stepped thickness piezoelectric plate mesa resonators made of polarized ceramics or 6-mm class crystals. A theoretical analysis based on the theory of piezoelectricity is performed, and an analytical solution is obtained using the trigonometric series. The electrical admittance, resonant frequencies, and mode shapes are calculated, and strong energy trapping of the modes is observed. Their dependence on the geometric parameters of the resonator is also examined.
Electrocatalytic Oxidation Of Formic Acid On Pd/Ni Heterostructured Catalyst,
2012
Shanghai Advanced Research Institute, Chinese Academy of Sciences (CAS), Shanghai 201210, China;Graduate School of the CAS, Beijing 100039, China;
Electrocatalytic Oxidation Of Formic Acid On Pd/Ni Heterostructured Catalyst, Mingjun Ren, Liangliang Zou, Ju Chen, Ting Yuan, Qinghong Huang, Haifeng Zhang, Hui Yang, Songlin Feng
Journal of Electrochemistry
A Pd/Ni bimetallic nanostructured electrocatalyst was fabricated via a two-step reduction route. Owing to an epitaxial growth of Pd atoms on the surface of Ni nanoparticles, heterostructured Pd/Ni nanocomposites were formed and verified by high resolution transmission electron microscopy combined with energy-dispersion X-ray spectroscopy. X-ray diffraction confirmed that the as-prepared Pd/Ni nanocomposites possessed a single face-centered-cubic (fcc) Pd structure, probably due to a weaker diffraction intensity of metallic Ni and/or overlapping by that of Pd. The intrinsic catalytic activity on the Pd/Ni is higher than that on the Pd. Moreover, the durability of formic acid oxidation on the Pd/Ni was …
Electrochemical Performance Of Screen-Printed Composite Coatings Of Conducting Polymers And Carbon Nanotubes On Titanium Bipolar Plates In Aqueous Asymmetrical Supercapacitors,
2012
Department of Chemical and Environmental Engineering, and Energy and Sustainability Research Division, Faculty of Engineering, University of Nottingham, Nottingham NG7 2RD, UK;
Electrochemical Performance Of Screen-Printed Composite Coatings Of Conducting Polymers And Carbon Nanotubes On Titanium Bipolar Plates In Aqueous Asymmetrical Supercapacitors, Xiaohang Zhou, George Z. Chen
Journal of Electrochemistry
Composites of conducting polymers (polypyrrole and polyaniline) with acid treated multi-walled carbon nanotubes were formulated into printable aqueous inks, with the aid of functional additives (benzethonium chloride as a surfactant with or without polyvinyl alcohol as a binder). The inks were screen-printed as fairly uniform coatings of various mass loading densities and areas (up to 75 mg cm-2 and 100 cm2) on thin titanium plates (0.1 mm in thickness). These screen-printed plates were used to fabricate both unit cell and multi-cell stack of asymmetrical supercapacitors with screen-printed negative electrodes of activated carbon (pigment black) in aqueous electrolytes …
