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Articles 3541 - 3570 of 6346

Full-Text Articles in Engineering

Aerodynamics And Control Of A Deployable Wing Uav For Autonomous Flight, Michael Thamann Jan 2012

Aerodynamics And Control Of A Deployable Wing Uav For Autonomous Flight, Michael Thamann

Theses and Dissertations--Mechanical and Aerospace Engineering

UAV development and usage has increased dramatically in the last 15 years. In this time frame the potential has been realized for deployable UAVs to the extent that a new class of UAV was defined for these systems. Inflatable wing UAVs provide a unique solution for deployable UAVs because they are highly packable (some collapsing to 5-10% of their deployed volume) and have the potential for the incorporation of wing shaping. In this thesis, aerodynamic coefficients and aileron effectiveness were derived from the equations of motion of aircraft as necessary parameters for autonomous flight. A wind tunnel experiment was performed …


Nanocrystals Of Chemotherapeutic Agents For Cancer Theranostics: Development And In Vitro And In Vivo Evaluation, Christin P. Hollis Jan 2012

Nanocrystals Of Chemotherapeutic Agents For Cancer Theranostics: Development And In Vitro And In Vivo Evaluation, Christin P. Hollis

Theses and Dissertations--Pharmacy

The majority of pharmacologically active chemotherapeutics are poorly water soluble. Solubilization enhancement by the utilization of organic solvents often leads to adverse side effects. Nanoparticle-based cancer therapy, which is passively targeted to the tumor tissue via the enhanced permeation and retention effect, has been vastly developed in recent years. Nanocrystals, which exist as crystalline and carry nearly 100% drug loading, has been explored for delivering antineoplastic agents. Additionally, the hybrid nanocrystal concept offers a novel and simple way to integrate imaging agents into the drug crystals, enabling the achievement of theranostics. The overall objective of this dissertation is to formulate …


Multihierarchical Documents And Fine-Grained Access Control, Neil Moore Jan 2012

Multihierarchical Documents And Fine-Grained Access Control, Neil Moore

Theses and Dissertations--Computer Science

This work presents new models and algorithms for creating, modifying, and controlling access to complex text. The digitization of texts opens new opportunities for preservation, access, and analysis, but at the same time raises questions regarding how to represent and collaboratively edit such texts. Two issues of particular interest are modelling the relationships of markup (annotations) in complex texts, and controlling the creation and modification of those texts. This work addresses and connects these issues, with emphasis on data modelling, algorithms, and computational complexity; and contributes new results in these areas of research.

Although hierarchical models of text and markup …


Development And Deployment Of A Bioreactor For The Removal Of Sulfate And Manganese From Circumneutral Coal Mine Drainage, C. B. Mastin, J. D. Edwards, Christopher D. Barton, Anastasios D. Karathanasis, Carmen T. Agouridis, Richard C. Warner Jan 2012

Development And Deployment Of A Bioreactor For The Removal Of Sulfate And Manganese From Circumneutral Coal Mine Drainage, C. B. Mastin, J. D. Edwards, Christopher D. Barton, Anastasios D. Karathanasis, Carmen T. Agouridis, Richard C. Warner

Forestry and Natural Resources Faculty Publications

Surface mining, in the form of contour mining and mountain-top removal, is a common means for retrieving coal in the Appalachian Coal Belt region of Kentucky. Overburden or excess spoil generated by these two methods is placed in valley fills. Traditionally Constructed fills have been shown to adversely impact headwater ecosystems via stream burial and through alterations to the hydrology, sediment supply, water quality and biological composition of downstream reaches. Mine drainages emanating from the toe of valley fills often contain elevated levels of total dissolved solids and heavy metals. Drainage chemistry from Guy Cove, a valley fill located in …


Evaluation Of Algae Concentration In Manure Based Media, Maira Freire Pecegueiro Do Amaral Jan 2012

Evaluation Of Algae Concentration In Manure Based Media, Maira Freire Pecegueiro Do Amaral

Theses and Dissertations--Biosystems and Agricultural Engineering

Algae can be used to treat wastewater and manure while producing a feedstock for renewable energy. Algae require nutrients to achieve their maximum growth and manure could provide those nutrients, thereby reducing the cost of algae production and the impact of manure treatment. Algae concentration during cultivation is a critical variable that is difficult to measure due to the high concentration of suspended solids present in manure. This dissertation addresses methods to measure algae concentration in the presence of manure solids.

Quantifying the algae concentration gravimetrically or by optical density was unreliable due to manure solids interfering with the measurement. …


Privacy Preserving Distributed Data Mining, Zhenmin Lin Jan 2012

Privacy Preserving Distributed Data Mining, Zhenmin Lin

Theses and Dissertations--Computer Science

Privacy preserving distributed data mining aims to design secure protocols which allow multiple parties to conduct collaborative data mining while protecting the data privacy. My research focuses on the design and implementation of privacy preserving two-party protocols based on homomorphic encryption. I present new results in this area, including new secure protocols for basic operations and two fundamental privacy preserving data mining protocols.

I propose a number of secure protocols for basic operations in the additive secret-sharing scheme based on homomorphic encryption. I derive a basic relationship between a secret number and its shares, with which we develop efficient secure …


Measuring Effectiveness Of Address Schemes For As-Level Graphs, Yinfang Zhuang Jan 2012

Measuring Effectiveness Of Address Schemes For As-Level Graphs, Yinfang Zhuang

Theses and Dissertations--Computer Science

This dissertation presents measures of efficiency and locality for Internet addressing schemes.

Historically speaking, many issues, faced by the Internet, have been solved just in time, to make the Internet just work~\cite{justWork}. Consensus, however, has been reached that today's Internet routing and addressing system is facing serious scaling problems: multi-homing which causes finer granularity of routing policies and finer control to realize various traffic engineering requirements, an increased demand for provider-independent prefix allocations which injects unaggregatable prefixes into the Default Free Zone (DFZ) routing table, and ever-increasing Internet user population and mobile edge devices. As a result, the DFZ routing …


Smart Grid Communications, Christopher W. Asbery Jan 2012

Smart Grid Communications, Christopher W. Asbery

Theses and Dissertations--Electrical and Computer Engineering

Smart grid technologies are starting to be the future of electric power systems. These systems are giving the utilities detailed information about their systems in real time. One of the most challenging things of implementing smart grid applications is employing the communications into the systems. Understanding the available communications can help ease the transition to these smart grid applications. Many of the utility personnel are spending too much time trying to figure out which communication is better for their application or applications. So this thesis presents the different communication types available with discussing the different attributes in which these communication …


Formulation And Solution Of Electromagnetic Integral Equations Using Constraint-Based Helmholtz Decompositions, Jin Cheng Jan 2012

Formulation And Solution Of Electromagnetic Integral Equations Using Constraint-Based Helmholtz Decompositions, Jin Cheng

Theses and Dissertations--Electrical and Computer Engineering

This dissertation develops surface integral equations using constraint-based Helmholtz decompositions for electromagnetic modeling. This new approach is applied to the electric field integral equation (EFIE), and it incorporates a Helmholtz decomposition (HD) of the current. For this reason, the new formulation is referred to as the EFIE-hd. The HD of the current is accomplished herein via appropriate surface integral constraints, and leads to a stable linear system. This strategy provides accurate solutions for the electric and magnetic fields at both high and low frequencies, it allows for the use of a locally corrected Nyström (LCN) discretization method for the resulting …


Comparing Acoustic Glottal Feature Extraction Methods With Simultaneously Recorded High-Speed Video Features For Clinically Obtained Data, Sean Michael Hamlet Jan 2012

Comparing Acoustic Glottal Feature Extraction Methods With Simultaneously Recorded High-Speed Video Features For Clinically Obtained Data, Sean Michael Hamlet

Theses and Dissertations--Electrical and Computer Engineering

Accurate methods for glottal feature extraction include the use of high-speed video imaging (HSVI). There have been previous attempts to extract these features with the acoustic recording. However, none of these methods compare their results with an objective method, such as HSVI. This thesis tests these acoustic methods against a large diverse population of 46 subjects. Two previously studied acoustic methods, as well as one introduced in this thesis, were compared against two video methods, area and displacement for open quotient (OQ) estimation. The area comparison proved to be somewhat ambiguous and challenging due to thresholding effects. The displacement comparison, …


Estimation Of Gap Acceptance Parameters For Hcm 2010 Roundabout Capacity Model Applications, A. Gazzarri, Michael T. Martello, Antonio Pratelli, Reginald R. Souleyrette Jan 2012

Estimation Of Gap Acceptance Parameters For Hcm 2010 Roundabout Capacity Model Applications, A. Gazzarri, Michael T. Martello, Antonio Pratelli, Reginald R. Souleyrette

Civil Engineering Faculty Publications

This paper deals with the field data observation and successive application of estimation procedures in order to estimate follow-up headway and critical headway at roundabouts. Average follow-up and average critical headway are two critical parameters in the new roundabout capacity model presented in the 2010 edition of the Highway Capacity Manual (HCM). The HCM 2010 capacity model was developed as an exponential regression model with parameter estimates based on gap acceptance theory. Gap acceptance models are strongly affected by driver behaviour and local habits. Follow-up headways can be field measured, while critical headway cannot be obtained directly. The paper mainly …


Automated System To Improve Levelness Of Reconstructed Soil, Venkata Srikiran Bodapati, Larry G. Wells Jan 2012

Automated System To Improve Levelness Of Reconstructed Soil, Venkata Srikiran Bodapati, Larry G. Wells

Biosystems and Agricultural Engineering Faculty Publications

Extraction of coal, ores, and minerals from the earth by surface mining has occurred for many years and has always presented a significant challenge with regard to restoration of productive soil to mined areas. Federal and state regulations require that land should be returned to pre-mine productivity or reclaimed as per specific standards following mining. Excessive compaction of reconstructed soil caused by traffic of heavy earth moving equipment has been an enduring challenge regarding successful restoration of soil. A mechanical system was previously designed and developed to reconstruct soil to a depth of 1.22 m (48 in.) while completely avoiding …


Prescribed Grazing On Pasturelands, Lynn E. Sollenberger, Carmen T. Agouridis, Eric S. Vanzant, Alan J. Franzluebbers, Lloyd B. Owens Jan 2012

Prescribed Grazing On Pasturelands, Lynn E. Sollenberger, Carmen T. Agouridis, Eric S. Vanzant, Alan J. Franzluebbers, Lloyd B. Owens

Biosystems and Agricultural Engineering Faculty Publications

No abstract provided.


Multimodal Imaging Evidence For Axonal And Myelin Deterioration In Amnestic Mild Cognitive Impairment, Brian T. Gold, Yang Jiang, David K. Powell, Charles D. Smith Jan 2012

Multimodal Imaging Evidence For Axonal And Myelin Deterioration In Amnestic Mild Cognitive Impairment, Brian T. Gold, Yang Jiang, David K. Powell, Charles D. Smith

Neuroscience Faculty Publications

White matter (WM) microstructural declines have been demonstrated in Alzheimer's disease and amnestic mild cognitive impairment (aMCI). However, the pattern of WM microstructural changes in aMCI after controlling for WM atrophy is unknown. Here, we address this issue through joint consideration of aMCI alterations in fractional anisotropy, mean diffusivity, axial diffusivity, and radial diffusivity, as well as macrostructural volume in WM and gray matter compartments. Participants were 18 individuals with aMCI and 24 healthy seniors. Voxelwise analyses of diffusion tensor imaging data was carried out using tract-based spatial statistics (TBSS) and voxelwise analyses of high-resolution structural data was conducted using …


Structural Basis Of Substrate Recognition In Thimet Oligopeptidase And Development Of Nanoparticles For Therapeutic Enzyme Delivery, Jonathan Mark Wagner Jan 2012

Structural Basis Of Substrate Recognition In Thimet Oligopeptidase And Development Of Nanoparticles For Therapeutic Enzyme Delivery, Jonathan Mark Wagner

Theses and Dissertations--Molecular and Cellular Biochemistry

Neuropeptidases are responsible for degradation of signaling peptides in the central nervous system and periphery. Some neuropeptidases have also been shown to play a role as part of the cell’s hydrolytic machinery responsible for breaking down proteins and peptides into amino acids, and these enzymes therefore influence small peptide availability for antigen presentation. A better understanding of how neuropeptidases recognize their substrates could lead to therapeutics that modulate the activity of these important enzymes. Alternatively, re-engineering these enzymes to selectively hydrolyze undesirable peptides could make them attractive as therapeutics themselves. A key question in understanding the activity of these enzymes …


Metallic Patterning Using An Atomic Force Microscope Tip And Laser-Induced Liquid Deposition, Carlos Andrés Jarro Sanabria Jan 2012

Metallic Patterning Using An Atomic Force Microscope Tip And Laser-Induced Liquid Deposition, Carlos Andrés Jarro Sanabria

Theses and Dissertations--Electrical and Computer Engineering

The development of nanoscale patterns has a vast variety of applications going from biology to solid state devices. In this research we present a new direct patterning technique in which laser photoreduction of silver from a liquid is controlled by a scanning atomic force microscope tip. While pursuing the formation of patterns using the plasmonic field enhancement of an electromagnetic wave incident on a metallic Atomic Force Microscope (AFM) tip, our group discovered that contrary to expectations, the tip suppresses, rather than enhances, deposition on the underlying substrate, and this suppression persists in the absence of the tip. Experiments presented …


Feedback Control For Electron Beam Lithography, Yugu Yang Jan 2012

Feedback Control For Electron Beam Lithography, Yugu Yang

Theses and Dissertations--Electrical and Computer Engineering

Scanning-electron-beam lithography (SEBL) is the primary technology to generate arbitrary features at the nano-scale. However, pattern placement accuracy still remains poor compared to its resolution due to the open-loop nature of SEBL systems. Vibration, stray electromagnetic fields, deflection distortion and hysteresis, substrate charging, and other factors prevent the electron-beam from reaching its target position and one has no way to determine the actual beam position during patterning with conventional systems. To improve the pattern placement accuracy, spatial-phase-locked electron-beam lithography (SPLEBL) provides feedback control of electron-beam position by monitoring the secondary electron signal from electron-transparent fiducial grids on the substrate. While …


Bifunctional Bisphosphonates For Delivering Biomolecules To Bone, Jivan N. Yewle Jan 2012

Bifunctional Bisphosphonates For Delivering Biomolecules To Bone, Jivan N. Yewle

Theses and Dissertations--Chemistry

Active targeting with controlled delivery of therapeutic agents to bone is an ideal approach for treatment of several bone diseases. Since bisphosphonates (BPs) are known to have high affinity to bone mineral and are being widely used in treatment of osteoporosis, they are well-suited for drug targeting to bone. For this purpose, bifunctional hydrazine-bisphosphonates (HBPs) with spacers of various lengths and lipophilicity were synthesized and studied. Crystal growth inhibition assays demonstrated that the HBPs with shorter spacers bound more strongly to bone mineral, hydroxyapatite (HA), than did alendronate. HBPs were also demonstrated to be non-toxic to MC3T3-E1 pre-osteoblasts. The targeted …


Investigations Of Oxidative Stress Effects And Their Mechanisms In Rat Brain After Systemic Administration Of Ceria Engineered Nanomaterials, Sarita S. Hardas Jan 2012

Investigations Of Oxidative Stress Effects And Their Mechanisms In Rat Brain After Systemic Administration Of Ceria Engineered Nanomaterials, Sarita S. Hardas

Theses and Dissertations--Chemistry

Advancing applications of engineered nanomaterials (ENM) in various fields create the opportunity for intended (e.g. drug and gene delivery) or unintended (e.g. occupational and environmental) exposure to ENM. However, the knowledge of ENM-toxicity is lagging behind their application development. Understanding the ENM hazard can help us to avoid potential human health problems associated with ENM applications as well as to increase their public acceptance. Ceria (cerium [Ce] oxide) ENM have many current and potential commercial applications. Beyond the traditional use of ceria as an abrasive, the scope of ceria ENM applications now extends into fuel cell manufacturing, diesel fuel additives …


Novel Design Of Functionalized Carbon Nanotube Electrodes And Membranes For Fuel Cells And Energy Storage, Xin Su Jan 2012

Novel Design Of Functionalized Carbon Nanotube Electrodes And Membranes For Fuel Cells And Energy Storage, Xin Su

Theses and Dissertations--Chemical and Materials Engineering

A novel electrochemical method to generate nm-scale bubbles at the tips of CNTs can temporarily block the membrane. A 92% blocking efficiency is achieved when the bubbles are stabilized in 30-60 nm diameter „wells‟ at the tips of CNTs. This well is formed by the electrochemical oxidation of the conductive CNTs partially into the polymer matrix of the membrane. Meanwhile, the nanoscale bubbles can be removed with 0.004 atm pressure to recover the transport through the CNT membrane. The CNT membrane with nanoscale bubble valve system was used to demonstrate electrochemical energy storage.

Uniform ultrathin Pt films were electrodeposited onto …


Protein Based Biomimetic Approachs To Surface Hemocompatibility And Biocompatibility Enhancement, Matthew Thomas Dickerson Jan 2012

Protein Based Biomimetic Approachs To Surface Hemocompatibility And Biocompatibility Enhancement, Matthew Thomas Dickerson

Theses and Dissertations--Chemical and Materials Engineering

T. pallidum can survive a primary immune response and continue growing in the host for an extended period of time. T. pallidum is thought to bind serum fibronectin (FN) through Tp0483 on the surface to obscure antigens. A Tp0483 fragment (rTp0483) was adsorbed onto functionalized self-assembled monolayers (SAMs) with FN. FN capture by adsorbed rTp0483 depended greatly on surface chemistry with COO- groups being best for FN binding. Hemocompatibility was determined by analysis of plasma protein adsorption, intrinsic pathway activation, and platelet activation. rTp0483+FN bound an equal or lesser amount of fibrinogen (Fg), human serum albumin (HSA), and factor XII …


Effect Of Ionic Surfactants On Electrostatic Charging Of Spray Droplets, Mark T. Warren Jan 2012

Effect Of Ionic Surfactants On Electrostatic Charging Of Spray Droplets, Mark T. Warren

Theses and Dissertations--Chemical and Materials Engineering

Dust capture for small coal particles (<2.5µm) can be improved if one takes advantage of electrostatic charges that resides on the surface of coal dust particles and on the surface of water spray droplets used to capture coal dust. Traditional dust capture methods that use water sprays are ineffective in capturing small dust particles since the motion of small dust particles is governed by electrostatic forces. If additives such as ionic surfactants could be added to water that would enhance the surface charge on water spray droplets, dust capture with water sprays could be improved.

The results presented show that n-sodium octyl sulfate causes the greatest charge enhancement versus the longer chained n-sodium dodecyl sulfate and n-sodium octadecyl sulfate. This can be explained by considering the factors that lead to droplet charge enhancement. Those factors are the mass of surfactant ions at the droplet surface, and the diffusion rate of the surfactant ions from the bulk droplet to the surface of the droplet. Sodium octyl sulfate will have a faster diffusion rate to the droplet surface because of its relatively short length, and will also maximize the mass …


Nanoparticle Additives For Multiphase Systems: Synthesis, Formulation And Characterization, Vinod Kanniah Jan 2012

Nanoparticle Additives For Multiphase Systems: Synthesis, Formulation And Characterization, Vinod Kanniah

Theses and Dissertations--Chemical and Materials Engineering

Study on nanoparticle additives in multiphase systems (liquid, polymer) are of immense interest in developing new product applications. Critical challenges for nanoparticle additives include their synthesis, formulation and characterization. These challenges are addressed in three application areas: nanofluids for engine lubrication, ultrathin nanocomposites for optical devices, and nanoparticle size distribution characterization.

Nanoparticle additives in oligomer mixtures can be used to develop extended temperature range motor oils. A model system includes poly(α-olefin) based oligomers with a modest fraction of poly(dimethylsiloxane) oligomers along with graphite as nanoparticle additive. Partition coefficients of each oligomer are determined since the oligomer mixture phase separated at …


Fabrication Of An Epithelial Cell-Based Ion-Selective Electrode And Its Application For Use As Alternative Tumor Angiogenesis Assay, Christina Nicole Simmons Jan 2012

Fabrication Of An Epithelial Cell-Based Ion-Selective Electrode And Its Application For Use As Alternative Tumor Angiogenesis Assay, Christina Nicole Simmons

Theses and Dissertations--Chemical and Materials Engineering

Previous studies have provided evidence that endothelial cell-based potassium ion selective electrodes possess the ability to quantify substances that have permeability-altering effects on those endothelial cells. The capability of these so-called biosensors to detect elevated concentrations of certain chemical agents found following tumor formation make them useful in the application as an alternative tumor angiogenesis assay. In this study an epithelial cell line, human colon adenocarcinoma epithelial cells (Caco-2), was used to fabricate membranes that were used to test concentrations of these chemical agents, known as cytokines, mimicking the concentrations that have been observed in the serum of healthy individuals …


Biodegradable Hydrogels And Nanocomposite Polymers: Synthesis And Characterization For Biomedical Applications, Ashley Marie Hawkins Jan 2012

Biodegradable Hydrogels And Nanocomposite Polymers: Synthesis And Characterization For Biomedical Applications, Ashley Marie Hawkins

Theses and Dissertations--Chemical and Materials Engineering

Hydrogels are popular materials for biological applications since they exhibit properties like that of natural soft tissue and have tunable properties. Biodegradable hydrogels provide an added advantage in that they degrade in an aqueous environment thereby avoiding the need for removal after the useful lifetime. In this work, we investigated poly(β-amino ester) (PBAE) biodegradable hydrogel systems. To begin, the factors affecting the macromer synthesis procedure were studied to optimize the reproducibility of the resulting hydrogels made and create new methods of tuning the properties. Hydrogel behavior was then tuned by altering the hydrophilic/hydrophobic balance of the chemicals used in the …


Understanding Degradation And Lithium Diffusion In Lithium Ion Battery Electrodes, Juchuan Li Jan 2012

Understanding Degradation And Lithium Diffusion In Lithium Ion Battery Electrodes, Juchuan Li

Theses and Dissertations--Chemical and Materials Engineering

Lithium-ion batteries with higher capacity and longer cycle life than that available today are required as secondary energy sources for a wide range of emerging applications. In particular, the cycling performance of several candidate materials for lithium-ion battery electrodes is insufficient because of the fast capacity fading and short cycle life, which is mainly a result of mechanical degradation.

This dissertation mainly focuses on the issue of mechanical degradation in advanced lithium-ion battery electrodes. Thin films of tin electrodes were studied where we observed whisker growth as a result of electrochemical cycling. These whiskers bring safety concerns because they may …


Application Of Thin Film Analysis Techniques And Controlled Reaction Environments To Model And Enhance Biomass Utilization By Cellulolytic Bacteria, Hsin-Fen Li Jan 2012

Application Of Thin Film Analysis Techniques And Controlled Reaction Environments To Model And Enhance Biomass Utilization By Cellulolytic Bacteria, Hsin-Fen Li

Theses and Dissertations--Chemical and Materials Engineering

Cellulose from energy crops or agriculture residues can be utilized as a sustainable energy resource to produce biofuels such as ethanol. The process of converting cellulose into solvents and biofuels requires the saccharification of cellulose into soluble, fermentable sugars. However, challenges to cellulosic biofuel production include increasing the activity of cellulose-degrading enzymes (cellulases) and increasing solvent (ethanol) yield while minimizing the co-production of organic acids. This work applies novel surface analysis techniques and fermentation reactor perturbations to quantify, manipulate, and model enzymatic and metabolic processes critical to the efficient production of cellulosic biofuels.

Surface analysis techniques utilizing cellulose thin film …


Membrane Immobilized Reactive Fe/Pd Nanoparticles: Modeling And Tce Degradation Results, Ruo He Jan 2012

Membrane Immobilized Reactive Fe/Pd Nanoparticles: Modeling And Tce Degradation Results, Ruo He

Theses and Dissertations--Chemical and Materials Engineering

Detoxification of chlorinated organic compound is an important and urgent issue in water remediation nowadays. Trichloroethylene (TCE), as a model compound in this study, has been proved to be degraded effectively by bimetallic nanoparticles (NPs) in solution phase. In this study, Fe/Pd bimetallic NPs were synthesized in poly (acrylic acid) (PAA) functionalized polyvinylidene fluoride (PVDF) microfiltration membranes. TCE dechlorination with these bimetallic NPs was conducted under different pH values and different metal loadings to study the role of corrosion on reaction rates.

One-dimensional mathematical model with pseudo first-order reaction kinetic was introduced to discuss the TCE dechlorination profile in membrane …


Finite Element Analysis Of The Contact Deformation Of Piezoelectric Materials, Ming Liu Jan 2012

Finite Element Analysis Of The Contact Deformation Of Piezoelectric Materials, Ming Liu

Theses and Dissertations--Chemical and Materials Engineering

Piezoelectric materials in the forms of both bulk and thin-film have been widely used as actuators and sensors due to their electromechanical coupling. The characterization of piezoelectric materials plays an important role in determining device performance and reliability. Instrumented indentation is a promising method for probing mechanical as well as electrical properties of piezoelectric materials.

The use of instrumented indentation to characterize the properties of piezoelectric materials requires analytical relations. Finite element methods are used to analyze the indentation of piezoelectric materials under different mechanical and electrical boundary conditions.

For indentation of a piezoelectric half space, a three-dimensional finite element …


Study Of Characterization Of Submicron Coal Particles Dispersed In Air And Capture Of Coal Particles By Water Drops In A Scrubbing Column, Utshab Chakravorty Jan 2012

Study Of Characterization Of Submicron Coal Particles Dispersed In Air And Capture Of Coal Particles By Water Drops In A Scrubbing Column, Utshab Chakravorty

Theses and Dissertations--Chemical and Materials Engineering

Present day water spray based dust removal technologies do not effectively remove respirable submicron coal and silica dust particles in the underground coal mines causing Coal worker’s pneumoconiosis (CWP). The objective of this research was to study the electrostatic charges present in the airborne coal dust in order to develop efficient water spraying based dust removal technology where water drops charged using ionic compounds and surfactants would be used to capture the oppositely charged coal particles. In an experimental scrubbing column, coal particles dispersed in an air stream by a Fluidized Bed Aerosol Generator were captured by water drops sprayed …