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2017

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Articles 1 - 30 of 9026

Full-Text Articles in Engineering

Automated Droplet Manipulation Through Electrowetting On Dielectric For Solid-Phase Oligonucleotide Synthesis, Hee Tae An Dec 2017

Automated Droplet Manipulation Through Electrowetting On Dielectric For Solid-Phase Oligonucleotide Synthesis, Hee Tae An

Journal of the Microelectronic Engineering Conference

No abstract provided.


Mems Fabrication Of A Peristaltic Pump, Nicholas Amendola Dec 2017

Mems Fabrication Of A Peristaltic Pump, Nicholas Amendola

Journal of the Microelectronic Engineering Conference

No abstract provided.


16-11 Microsimulation Of The Impact Of Access Management Practices To Pedestrians, Deo Chimba, Kevin Soloka Dec 2017

16-11 Microsimulation Of The Impact Of Access Management Practices To Pedestrians, Deo Chimba, Kevin Soloka

Transportation Research Center Reports

The study applied microsimulation to analyze the impact of access management (AM) to the operational performances of vehicles and pedestrians. A conceptual model was developed in VISSIM and VISWALK to examine the effect of access and signals density on different median types to the travel speed, travel time, delay and stopping. Access density, signal density, and presence of median were simulated in a scenario base analysis. The model scenarios shifted through changing both access density and signal density with no median, raised median and TWLT lane to provide interactions of arterial corridors in Nashville. The effect of access density on ...


Development Of Economic Water Usage Sensor And Cyber-Physical Systems Co-Simulation Platform For Home Energy Saving, Joe Singer Dec 2017

Development Of Economic Water Usage Sensor And Cyber-Physical Systems Co-Simulation Platform For Home Energy Saving, Joe Singer

Mechanical Engineering Master's Theses

In this thesis, two Cyber-Physical Systems (CPS) approaches were considered to reduce residential building energy consumption. First, a flow sensor was developed for residential gas and electric storage water heaters. The sensor utilizes unique temperature changes of tank inlet and outlet pipes upon water draw to provide occupant hot water usage. Post processing of measured pipe temperature data was able to detect water draw events. Conservation of energy was applied to heater pipes to determine relative internal water flow rate based on transient temperature measurements. Correlations between calculated flow and actual flow were significant at a 95% confidence level. Using ...


Vulnerability Assessment Of Sign-Support Structures During Transportation And In Service, Saeed Arabi Dec 2017

Vulnerability Assessment Of Sign-Support Structures During Transportation And In Service, Saeed Arabi

Graduate Theses and Dissertations

Dynamic Message Signs (DMSs) are increasingly used in highways as an effective means to communicate time-sensitive information with motorists. To ensure their long-term performance, it is critical to ensure that the truss structures that hold them can resist not only extreme loading events, but also fatigue induced by service loads. For this purpose, a comprehensive study has been conducted on the fatigue performance of this important category of structures. The current study evaluates the fatigue performance of DMS-support structures during transportation under road-induced excitations as well as throughout their service life under loads induced by environmental stressors. In the first ...


16-02 Enhancing Non-Motorized Mobility Within Construction Zones, Upul Attanayake, Abul Fazal Mazumder, Wjdan Dhaif Sahi Sahi, Mathew Mueller, Dustin Black Dec 2017

16-02 Enhancing Non-Motorized Mobility Within Construction Zones, Upul Attanayake, Abul Fazal Mazumder, Wjdan Dhaif Sahi Sahi, Mathew Mueller, Dustin Black

Transportation Research Center Reports

Acquisition of lanes and sidewalks for construction activities increases congestion and delays and compromises safety. Further, work zones impair access to local businesses, bus stops, nearby facilities, etc., while hindering mobility of pedestrians, cyclists, and emergency responders. The emphasis on non-motorized mobility varies significantly when temporary traffic control management plans are developed for small cities. Due to lack of specific instructions given to contractors and the potential liability issues, contractors tend to completely close access to non-motorized traffic without providing alternate routes or detours. Instead of using a detour, pedestrians and cyclists tend to pass through the construction zone or ...


Comparative Analysis Of The Dissolution Performance Of Aspirin Tablets In The Usp Apparatus 2 And In A Minivessel Dissolution System, Annmarie C. Walker Dec 2017

Comparative Analysis Of The Dissolution Performance Of Aspirin Tablets In The Usp Apparatus 2 And In A Minivessel Dissolution System, Annmarie C. Walker

Theses

Dissolution testing is a critical component of quality control procedures in the pharmaceutical industry in order to ensure that the final solid dosage forms have consistent dissolution properties. Dissolution tests are also routinely conducted to evaluate the in-vitro performance of solid dosage forms during pharmaceutical development, to aid in the behavior of formulations, and to optimize drug release from dosage forms.

The use of compendial dissolution test apparatus and techniques, such as the USP 2 (Paddle), to characterize the dissolution performance of oral drug delivery system is an established area of pharmaceutical science. However, this method is not always appropriate ...


Evaluating The Impact Of Adopting 3d Printing Services On The Retailers, Sharareh Rajaei Dehkordi Dec 2017

Evaluating The Impact Of Adopting 3d Printing Services On The Retailers, Sharareh Rajaei Dehkordi

Dissertations

As additive manufacturing technology becomes more responsive to consumers’ demand, one important question for the retailers is whether they should provide 3D printing services in their brick-and-mortar store in addition to the traditional off-the-shelf product? If so, what should be the retailers pricing scheme to achieve a higher profit? What should be the optimal inventory level of off-the-shelf products? What is the optimal capacity of 3D printers? In this study, stochastic models are examined to capture the joint optimal 3D product price and capacity of 3D printers to maximize retailer’s expected profit while considering consumer product choices. Moreover, a ...


Carbon Fiber Electrodes For In Vivo Neural Recording, Esma Cetinkaya Dec 2017

Carbon Fiber Electrodes For In Vivo Neural Recording, Esma Cetinkaya

Theses

Multi-channel micro electrodes for neural recording is a growing field that thrives on novel materials and fabrication techniques offered by micro fabrication technology. The material and the design of microelectrodes have a critical role on the quality of neural signals recorded. The neural signals collected by chronic implantation of these devices in experimental animals reveal new information about the brain functions and guide the development of new diagnostic and treatment options for neurological disorders.

Ideally, a microelectrode should meet two important criteria: longevity after implantation and minimal tissue insult. Carbon fibers` high tensile strength and flexibility allow fabrication of micro-scale ...


Computational And Experimental Determination Of The Mixing Efficiency Of A Microfluidic Serpentine Micromixer, Siril Arockiam Dec 2017

Computational And Experimental Determination Of The Mixing Efficiency Of A Microfluidic Serpentine Micromixer, Siril Arockiam

Theses

In microfluidics, efficiency and mixing time are the greatest disadvantages. These parameters hinder the application of microfluidic devices for biochemical and immunological assays. However, once these disadvantages have been overcome by optimizing the parameters of the microfluidic device, it becomes the important analytical tool. In this experiment, various designs of microfluidic devices have been both simulated using COMSOL software, and experimentally verified to obtain the optimized parameter such as depth and velocity for better mixing efficiency. The COMSOL model has been validated by comparing the results with fluorescent images data of the experiment. The microfluidic device is built with Adhesive ...


Formulation Of Uv Curable Resins Utilized In Vat Photo Polymerization For The Additive Manufacturing Of Gun Propulsion Charge In 3d Printers, David T. Bird Dec 2017

Formulation Of Uv Curable Resins Utilized In Vat Photo Polymerization For The Additive Manufacturing Of Gun Propulsion Charge In 3d Printers, David T. Bird

Theses

Formulating resins for Additive Manufacturing (AM), utilizing UV laser stereolithography, is a new technique that makes it possible for the fabrication of complex geometries with high dimensional resolution. This layer by layer photopolymerization approach spans various industrial sectors from adhesives, inks and optical fibers to nanotechnology and biomaterials. UV curable resins such as epoxides, vinyl ethers and other acrylates are important monomers that offer effective mediums for energetic materials, and the potential exists to develop environmentally friendly formulations with suspended energetic materials at various solids loading levels.

Developing techniques for UV curing formulations of highly loaded energetic suspensions is a ...


Electrical Properties Of Metal/Wse2structures, Zeel Rajiv Gandhi Dec 2017

Electrical Properties Of Metal/Wse2structures, Zeel Rajiv Gandhi

Theses

The formation of low resistance metal contacts on two-Dimensional layer (2-D) of WSe2 is a big challenge. In this research, a comparative study is presented on the electrical properties of metal/WSe2 Schottky barrier diodes with various metals such as Au, In, Al, and Ga in the temperature range of 80K to 400K well within the domain of thermionic emission theory.

Topics covered here include the factors that determine the Schottky barrier height, the device capacitance, and its current-voltage (I-V) characteristics. I-V curves for different metals on WSe2 are analyzed as function of temperature. Barrier height is determined from Au-nWSe2 ...


General Design Procedure For Free And Open-Source Hardware For Scientific Equipment, Shane W. Oberloier, Joshua M. Pearce Dec 2017

General Design Procedure For Free And Open-Source Hardware For Scientific Equipment, Shane W. Oberloier, Joshua M. Pearce

Department of Materials Science and Engineering Publications

Distributed digital manufacturing of free and open-source scientific hardware (FOSH) used for scientific experiments has been shown to in general reduce the costs of scientific hardware by 90–99%. In part due to these cost savings, the manufacturing of scientific equipment is beginning to move away from a central paradigm of purchasing proprietary equipment to one in which scientists themselves download open-source designs, fabricate components with digital manufacturing technology, and then assemble the equipment themselves. This trend introduces a need for new formal design procedures that designers can follow when targeting this scientific audience. This study provides five steps in ...


Monitoring Of Corrosion Process In Structural Adhesive Using Smart Materials, Yee Yan Lim, Iman Izadgoshasb, Scott T. Smith Dec 2017

Monitoring Of Corrosion Process In Structural Adhesive Using Smart Materials, Yee Yan Lim, Iman Izadgoshasb, Scott T. Smith

Dr Iman Izadgoshasb

The use of structural adhesives, such as epoxy, for the strengthening and repair of civil infrastructure is gaining popularity in the engineering community. Of particular concern to the viability of intervention measure is the degradation of strength and durability of the epoxy over time, especially when exposed to aggressive environments. Monitoring the corrosion process of epoxy is thus essential to ensure safety of the host structure. In this paper, the electromechanical impedance (EMI) technique that employs a smart piezoelectric transducer is used to monitor the degradation process of commercially available epoxy when exposed to corrosive environments. Standard epoxy coupons with ...


Luminescence Of Defects In The Structural Transformation Of Layered Tin Dichalcogenides, Peter Sutter, H.P. Komsa, A. V. Krasheninnikov, Y Huang, Eli A. Sutter Dec 2017

Luminescence Of Defects In The Structural Transformation Of Layered Tin Dichalcogenides, Peter Sutter, H.P. Komsa, A. V. Krasheninnikov, Y Huang, Eli A. Sutter

Faculty Publications from the Department of Electrical and Computer Engineering

Layered tin sulfide semiconductors are both of fundamental interest and attractive for energy conversion applications. Sn sulfides crystallize in several stable bulk phases with different Sn:S ratios (SnS2, Sn2, S3, and SnS), which can transform into phases with a lower sulfur concentration by introduction of sulfur vacancies (VS). How this complex behavior affects the optoelectronic properties remains largely unknown but is of key importance for understanding light-matter interactions in this family of layered materials. Here, we use the capability to induce VS and drive a transformation between few-layer SnS2 and SnS by electron beam irradiation, combined with in-situ cathodoluminescence ...


A Post-American World? Assessing The Cognitive And Attitudinal Impacts Of Challenges To American Exceptionalism, Jason Gilmore, Charles Rowling Dec 2017

A Post-American World? Assessing The Cognitive And Attitudinal Impacts Of Challenges To American Exceptionalism, Jason Gilmore, Charles Rowling

Languages, Philosophy, and Communication Studies Faculty Publications

A number of voices have emerged in U.S. political discourse questioning the legitimacy of American exceptionalism, suggesting we are in a “post-American world.” Our research examines the effects that political messages that explicitly challenge American exceptionalism can have on U.S. public opinion. Drawing upon social identity theory, we find that explicit challenges to American exceptionalism significantly impact Americans’ views toward their own nation, their willingness to denigrate foreign publics, and their broader foreign policy preferences.


Texture Development And Coercivity Enhancement In Cast Alnico 9 Magnets, Wenyong Zhang, Shah Valloppilly, Xingzhong Li, Lanping Yue, Ralph Skomski, Iver E. Anderson, Matthew J. Kramer, Wei Tang, Jeff Shield, David J. Sellmyer Dec 2017

Texture Development And Coercivity Enhancement In Cast Alnico 9 Magnets, Wenyong Zhang, Shah Valloppilly, Xingzhong Li, Lanping Yue, Ralph Skomski, Iver E. Anderson, Matthew J. Kramer, Wei Tang, Jeff Shield, David J. Sellmyer

Ames Laboratory Accepted Manuscripts

The effect of Y addition and magnetic field on texture and magnetic properties of arc-melted alnico 9 magnets has been investigated. Small additions of Y (1.5 wt.%) develop a (200) texture for the arc-melted alnico 9 magnet. Such a texture is hard to form in cast samples. To achieve this goal, we set up a high-field annealing system with a maximum operation temperature of 1250 °C. This system enabled annealing in a field of 45 kOe with subsequent draw annealing for the solutionized buttons; we have been able to substantially increase remanence ratio and coercivity, from 0.70 and ...


Microfluidic Pore Model Study On Physical And Geomechanical Factors Influencing Fluid Flow Behavior In Porous Media, Shuang Cao Dec 2017

Microfluidic Pore Model Study On Physical And Geomechanical Factors Influencing Fluid Flow Behavior In Porous Media, Shuang Cao

LSU Doctoral Dissertations

Fluid flow in porous media is a subject of fundamental importance and relevant to numerous engineering applications. The comprehensive description of fluid interaction parameters containing wetting properties, fluid-fluid displacement ratio, and capillary pressure, are inevitably needed. Moreover, the fine-grained sediments’ response to various pore fluids and migration in porous media influences reservoir geomechanical properties and pore clogging is essential to a better understanding of fluids flow behavior.

This dissertation provides a detailed study of physical and geomechanical factors influencing fluids flow behavior in porous media. The two-dimensional micromodel tests have been conducted under a wide selection of fluids flow conditions ...


Double Hysteresis Loops At Room Temperature In Nanbo3-Based Lead-Free Antiferroelectric Ceramics, Xiaoli Tan, Zunping Xu, Xiaoming Liu, Zhongming Fan Dec 2017

Double Hysteresis Loops At Room Temperature In Nanbo3-Based Lead-Free Antiferroelectric Ceramics, Xiaoli Tan, Zunping Xu, Xiaoming Liu, Zhongming Fan

Materials Science and Engineering Publications

Polarization-field double hysteresis loops have hardly ever been observed at room temperature in polycrystalline NaNbO3, one of a few lead-free antiferroelectric compounds. In this Letter, it is shown that the exposure of a modified NaNbO3 ceramic to bipolar electric fields of ±160 kV/cm at 100°C can preserve the double hysteresis loops at room temperature. These double hysteresis loops can still be observed after 125 days room temperature aging with some decay in maximum polarization. Frequency dependence analysis suggests that the double hysteresis loops originate from the antiferroelectric ↔ ferroelectric phase transition, not the charged defects.

A novel electrical treatment ...


Smart-Based Monitoring Of Epoxy Using Piezoelectric Transducers, Yee Yan Lim, Iman Izadgoshasb, Scott T. Smith Dec 2017

Smart-Based Monitoring Of Epoxy Using Piezoelectric Transducers, Yee Yan Lim, Iman Izadgoshasb, Scott T. Smith

Dr Iman Izadgoshasb

Structural adhesives are an important component of strengthening and repair techniques for structures. Adequate and proper curing of such materials is essential to achieve its desired strength and durability. In this study, the curing process of epoxy type Sikadur 330 is monitored using the electromechanical impedance (EMI) technique employing smart piezoelectric material, namely Lead Zirconate Titanate (PZT). Experimental results show that the PZT transducer embedded into the epoxy in liquid state is effective in monitoring the initial setting and the subsequent hardening process of a lab scale epoxy coupon. Rightward movement of both the PZT resonance peaks and the structural ...


Detection, Diagnosis And Mitigation Of Malicious Javascript With Enriched Javascript Executions, Xunchao Hu Dec 2017

Detection, Diagnosis And Mitigation Of Malicious Javascript With Enriched Javascript Executions, Xunchao Hu

Dissertations - ALL

Malicious JavaScript has become an important attack vector for software exploitation attacks and imposes a severe threat to computer security. In particular, three major class of problems, malware detection, exploit diagnosis, and exploits mitigation, bring considerable challenges to security researchers. Although a lot of research efforts have been made to address these threats, they have fundamental limitations and thus cannot solve the problems.

Existing analysis techniques fall into two general categories: static analysis and dynamic analysis. Static analysis tends to produce inaccurate results (both false positive and false negative) and is vulnerable to a wide series of obfuscation techniques. Thus ...


Cell Laden Hydrogel Microspheres Using 3d Printed Microfluidics, Sanika Nitin Suvarnapathaki Dec 2017

Cell Laden Hydrogel Microspheres Using 3d Printed Microfluidics, Sanika Nitin Suvarnapathaki

Theses - ALL

Cell laden hydrogel microspheres using 3D printed microfluidics

Abstract

By

Sanika Suvarnapathaki

Current tissue engineering therapies use macro-scale three dimensional (3D) scaffolds to treat tissue defects surgically. Uneven cell seeding and oxygen and media perfusion cause low cell viability in these macro-scale scaffolds. Microencapsulation, a technique of encapsulating cells in biocompatible polymers or hydrogels, has the potential to address these key issues, and therefore this technology has been used for numerous healthcare applications over the last two decades. Cell microencapsulation in hydrogels that mimic the tissue physiology and biochemistry has made it possible to use natural hydrogels like gelatin methacrylate ...


Online Learning With Bandits For Coverage, Mahmuda Rahman Dec 2017

Online Learning With Bandits For Coverage, Mahmuda Rahman

Dissertations - ALL

With the rapid growth in velocity and volume, streaming data compels decision support systems to predict a small number of unique data points in due time that can represent a massive amount of correlated data without much loss of precision. In this work, we formulate this problem as the {\it online set coverage problem} and propose its solution for recommendation systems and the patrol assignment problem.

We propose a novel online reinforcement learning algorithm inspired by the Multi-Armed Bandit problem to solve the online recommendation system problem. We introduce a graph-based mechanism to improve the user coverage by recommended items ...


Gas Phase Oxidation Of Levulinic Acid For The Production Of Maleic Anhydride Over Supported Vanadium Oxide Catalysts, Anargyros Chatzidimitriou Dec 2017

Gas Phase Oxidation Of Levulinic Acid For The Production Of Maleic Anhydride Over Supported Vanadium Oxide Catalysts, Anargyros Chatzidimitriou

Dissertations - ALL

With continued depletion of fossil carbon, there is a need to utilize renewable sources of energy and consumer end products. In this context, we examine the aerobic oxidation of levulinic acid, a bio-based platform chemical derived from lignocellulosic biomass, to produce maleic anhydride, a valuable commodity chemical. This process is carried out over supported vanadium oxide catalysts. Yields as high as 71% of the theoretical maximum were achieved at 573 K over a vanadium oxide catalyst supported on SiO2. The exact mechanism underlying this transformation is complex, but our results suggest that maleic anhydride forms by the oxidative cleavage of ...


Oxygen Transport Membrane Reactors For Oxy-Fuel Combustion And Carbon Capture Purposes, Ryan Falkenstein-Smith Dec 2017

Oxygen Transport Membrane Reactors For Oxy-Fuel Combustion And Carbon Capture Purposes, Ryan Falkenstein-Smith

Dissertations - ALL

This thesis investigates oxygen transport membrane reactors (OTMs) for the application of oxy-fuel combustion. This is done by evaluating the material properties and oxygen permeability of different OTM compositions subjected to a variety of operating conditions. The scope of this work consists of three components: (1) evaluate the oxygen permeation capabilities of perovskite-type materials for the application of oxy-fuel combustion; (2) determine the effects of dual-phase membrane compositions on the oxygen permeation performance and membrane characteristics; and (3) develop a new method for estimating the oxygen permeation performance of OTMs utilized for the application of oxy-fuel combustion.

SrSc0.1Co0.9O3-δ ...


Rectangular Waveguide Filled With Uniaxial Medium And Negative Resistance Enhanced Composite Right/Left-Handed Transmission Line, Kepei Sun Dec 2017

Rectangular Waveguide Filled With Uniaxial Medium And Negative Resistance Enhanced Composite Right/Left-Handed Transmission Line, Kepei Sun

Dissertations - ALL

Two wave-guiding problems are treated in this work. The first part addresses the problem of a rectangular waveguide filled with a uniaxially anisotropic or uniaxial medium. Different orientations of the optic axis of the uniaxial medium are considered and the wave transmission and modal behaviors are investigated. When the optic axis is aligned with one of the coordinate axes, i. e., x, y, or z axis, the method of wave decomposition with respect to the optic axis orientation is proposed and the complete analytic solutions are presented and compared with conventional transverse-to-z solutions. When the optic axis is tilted but ...


Ensemble Methods For Anomaly Detection, Zhiruo Zhao Dec 2017

Ensemble Methods For Anomaly Detection, Zhiruo Zhao

Dissertations - ALL

Anomaly detection has many applications in numerous areas such as intrusion detection, fraud detection, and medical diagnosis. Most current techniques are specialized for detecting one type of anomaly, and work well on specific domains and when the data satisfies specific assumptions.

We address this problem, proposing ensemble anomaly detection techniques that perform well in many applications, with four major contributions: using bootstrapping to better detect anomalies on multiple subsamples, sequential application of diverse detection

algorithms, a novel adaptive sampling and learning algorithm in which the anomalies are iteratively examined, and improving the random forest algorithms for detecting anomalies in streaming ...


Investigating The Interaction Of A Supersonic Single Expansion Ramp Nozzle And Sonic Wall Jet, Matthew Berry Dec 2017

Investigating The Interaction Of A Supersonic Single Expansion Ramp Nozzle And Sonic Wall Jet, Matthew Berry

Dissertations - ALL

For nearly 80 years, the jet engine has set the pace for aviation technology around the world. Complexity of design has compounded upon each iteration of nozzle development, while the rate of fundamental fluids knowledge struggles to keep up. The increase in velocities associated with supersonic jets, have exacerbated the need for flow physics research. Supersonic flight remains the standard for military aircraft and is being rediscovered for commercial use. With the addition of multiple streams, complex nozzle geometries, and airframe integration in modern aircraft, the flow physics rapidly become more difficult. As performance capabilities increase, so do the noise ...


Design, Synthesis And Study Of Thermomechanically Active Polymer Networks Based On Latent Crosslinking Of Semicrystalline Polymers, Wenbin Kuang Dec 2017

Design, Synthesis And Study Of Thermomechanically Active Polymer Networks Based On Latent Crosslinking Of Semicrystalline Polymers, Wenbin Kuang

Dissertations - ALL

Demand has arisen rapidly for smart materials in the world of the need to develop and understand new functional products like plastics, rubber, adhesives, fibers, and coatings. Such products are essentially composed of polymers, large molecules of high molecular weight with homogeneous or various repeating units, which researchers term “macromolecules” that engender specific structural, morphological, and physical and mechanical properties. Those polymers with the capacity to change their configuration in accordance with environmental alteration are specifically referred to as shape memory polymers (SMPs), attracting much interest of study both academically and industrially. Herein, this dissertation aims at design, fabrication, and ...


Associative Pattern Recognition For Biological Regulation Data, Yiou Xiao Dec 2017

Associative Pattern Recognition For Biological Regulation Data, Yiou Xiao

Dissertations - ALL

In the last decade, bioinformatics data has been accumulated at an unprecedented rate, thanks to the advancement in sequencing technologies. Such rapid development poses both challenges and promising research topics. In this dissertation, we propose a series of associative pattern recognition algorithms in biological regulation studies. In particular, we emphasize efficiently recognizing associative patterns between genes, transcription factors, histone modifications and functional labels using heterogeneous data sources (numeric, sequences, time series data and textual labels).

In protein-DNA associative pattern recognition, we introduce an efficient algorithm for affinity test by searching for over-represented DNA sequences using a hash function and modulo ...