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2016

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Articles 5161 - 5190 of 9607

Full-Text Articles in Engineering

Enhanced Seismic Performance Of Special Truss Moment Frames And Staggered Truss Framing System For Seismically Active Areas, Sanputt Simasathien May 2016

Enhanced Seismic Performance Of Special Truss Moment Frames And Staggered Truss Framing System For Seismically Active Areas, Sanputt Simasathien

Civil Engineering Dissertations - Archive

Due to their ability to achieve large column-free floor spaces, special truss moment frames (STMFs) and staggered truss frames (STFs) are unique valuable options for structural engineers. However, although STMFs and STFs offer a wide range of structural, architectural, and economical benefits, limited research data is available on the seismic performance of these systems. STMF system is a relatively new type of steel framing system for use in high seismic areas. STMFs dissipate earthquake energy through ductile special segments located near the mid-span of the truss girders, while the other members outside the special segment, including truss members, columns, and …


Investigation Of Strength-Enhancement Mechanism And Size Effect On Ultimate Shear Strength Of Steel Fiber-Reinforced Concrete (Sfrc) Slender Beams, Mohammad Reza Zarrinpour May 2016

Investigation Of Strength-Enhancement Mechanism And Size Effect On Ultimate Shear Strength Of Steel Fiber-Reinforced Concrete (Sfrc) Slender Beams, Mohammad Reza Zarrinpour

Civil Engineering Dissertations - Archive

This research study consists of two separate phases. In the first phase, an experimental study was conducted to identify the shear-enhancement and failure mechanisms behind the ultimate shear strength of steel fiber-reinforced concrete (SFRC) slender beams by utilizing the full field deformation measuring capability of digital image correlation (DIC) technology. A total of 12 large-scale simply supported SFRC and RC beams with a range of heights including 12 in. (305 mm), 18 in. (457 mm), 24 in. (610 mm), 36 in. (915 mm), and 48 in. (1220 mm) were tested under monotonic point load. The greater shear strength in SFRC …


Particle Image Velocimetry Design & Installation, Zach Ritchie May 2016

Particle Image Velocimetry Design & Installation, Zach Ritchie

Mechanical Engineering Undergraduate Honors Theses

This work will mainly focus on the design, construction, and installation of the Particle Image Velocimetry (PIV) system in the Chemical Hazards Research Center wind tunnel. The PIV system utilizes a Class IV (double pulsed) laser, optics to produce a light sheet, timing circuitry, and a high-resolution camera (with buffered output) to measure a system’s velocity (two-dimensional) field by determining the displacement of particles over the time between laser pulses. For maximum mobility and functionality, the PIV system was installed in the center of the tunnel on a moveable cart with the laser and camera mounted to an adjustable support. …


Manipulating The K-Space For Reduction Of Respiratory Induced Motion Artifacts, Maida Ranjbar May 2016

Manipulating The K-Space For Reduction Of Respiratory Induced Motion Artifacts, Maida Ranjbar

Bioengineering Theses - Archive

Respiratory induced motion artifacts, particularly those occurring in the abdomen and lung, pose a hefty problem in current diagnostic MR imaging. Application of images plagued with such artifacts not only hinder diagnosis, but may result in the enforcement of undesirably large safety margins in radiation therapy due to un-captured tumor characteristics that are concealed by the artifact. While several methods such as gated scans, breath-hold scans, variation of the K-Space acquisition trajectory, and reducing the scan time via partial acquisition or parallel imaging have been proposed as a solution, a robust and yet simple to implement remedy still remains to …


The Effect Of Cure Rate On Glassy Polymer Networks, Kristen M. Van De Voorde May 2016

The Effect Of Cure Rate On Glassy Polymer Networks, Kristen M. Van De Voorde

Honors Theses

The formation of glassy polymer networks such as epoxy-amine systems may be altered by varying the temperature ramp rate that is used to cure the system. As a result, the physical and mechanical properties of the network may be changed. This work synthesized the epoxy resins diglycidyl ether of bisphenol A (DGEBA) with the amine curing agent 4,4-diaminodiphenyl sulfone (4,4’-DDS) from 35°C to 180°C using varying temperature ramp rates. Mechanical and structural properties of these samples were then analyzed to determine the effect the different temperature ramp rates had on the formation and properties of the thermoset matrix. These aspects …


Automated Data Acquisition Of Deet Time-Dependent Concentration Profiles, Ryan D. Coleman May 2016

Automated Data Acquisition Of Deet Time-Dependent Concentration Profiles, Ryan D. Coleman

Honors Theses

Spatial insect repellents must maintain a sufficient concentration in the vapor phase to successfully deter pests. However, little is known regarding correlation of concentration to efficacy nor does there exist a standard testing protocol to measure efficacy in air. Among existing spatial repellents, DEET is the most common active ingredient. This research focuses on application of sensor-based technologies to monitor the concentration levels of DEET under static conditions.

Metal oxide semiconductor sensors feature conductivity variance in response to absorption and desorption of volatile organic compounds. Advantages of these sensors include cost, versatility, and sensitivity. Metal oxide semiconductor sensors were chosen …


Synthesis Of Acceptors For Use In Donor-Acceptor Copolymers And Characterization Of These Polymers, William D. Walker May 2016

Synthesis Of Acceptors For Use In Donor-Acceptor Copolymers And Characterization Of These Polymers, William D. Walker

Honors Theses

In this thesis, a selenium-derivatized acceptor was synthesized to examine the heavy atom effects of selenium on the position of the frontier molecular orbitals (HOMO/LUMO band gap) as opposed to sulfur in a donor-acceptor copolymer for use in light harvesting and detection applications. Over the course of this research, standard operating protocols for ultraviolet-visible (UV-Vis-NIR) and Fourier transform infrared (FT-IR) spectroscopies, as well as cyclic voltammetry (CV) characterization techniques were established. Once synthesized, the polymers were characterized through use of the established characterization protocols. The selenium-derivatized polymer exhibited a bathochromic shift compared to the sulfur analogue, with a solid-state absorption …


Improving Kinematic Accuracy Of Soft Wearable Data Gloves By Optimizing Sensor Locations, Donghyun Kim, Sang Wook Lee, Hyung-Soon Park May 2016

Improving Kinematic Accuracy Of Soft Wearable Data Gloves By Optimizing Sensor Locations, Donghyun Kim, Sang Wook Lee, Hyung-Soon Park

Electrical and Computer Engineering Faculty Research & Creative Works

Bending sensors enable compact, wearable designs when used for measuring hand configurations in data gloves. While existing data gloves can accurately measure angular displacement of the finger and distal thumb joints, accurate measurement of thumb carpometacarpal (CMC) joint movements remains challenging due to crosstalk between the multi-sensor outputs required to measure the degrees of freedom (DOF). To properly measure CMC-joint configurations, sensor locations that minimize sensor crosstalk must be identified. This paper presents a novel approach to identifying optimal sensor locations. Three-dimensional hand surface data from ten subjects was collected in multiple thumb postures with varied CMC-joint flexion and abduction …


Using Ceramic Waste Powder In Producing Self-Compacting Concrete, Sama Tarek Sayed Taha May 2016

Using Ceramic Waste Powder In Producing Self-Compacting Concrete, Sama Tarek Sayed Taha

Civil and Environmental Theses

Self-compacted (i.e. consolidated) concrete (SCC) is a special type of concrete that represents a great advancement towards a better quality of sustainable concrete. This unique type is known for its high flowability and superior levels of surface finish without tendency for segregation. The inherited distinct features can be achieved by the addition of high powder content as filler (i.e. size < 0. 125 mm) in the concrete mixture. The filler enhances the rheological properties of the SCC mixture without the need for using higher cement contents and hence, reduces the cost and heat of hydration. Lately, various regulating measures were imposed by governments and environmental organizations all over the world to seize the negative impact on the ecosystem resulting from huge amounts of solid waste materials being dumped in landfills causing major environmental problems. As a result, the utilization of alternative industrial waste constituents in construction materials has been the research focus for many years to evaluate their competence in SCC industry, and their feasibility as filler materials. In this study, ceramic waste powder (CWP) produced during the polishing process of ceramic tiles will be particularly investigated. Fresh and hardened tests are conducted to evaluate the influence of CWP on the rheological and mechanical properties of SCC mixtures. It was concluded that CWP can be used to successfully produce SCC mixtures with improved fresh and hardened properties. The inclusion of CWP up to 200 kg/m3 in SCC mixtures resulted in denser compacted mixtures with low permeability characteristics and high strength values. In addition to enhanced segregation resistance with good deformability and passing abilities for the mixtures under their own weight. The successful completion of …


Joint Resource Provisioning In Optical Cloud Networks, Pan Yi May 2016

Joint Resource Provisioning In Optical Cloud Networks, Pan Yi

School of Computing: Dissertations, Theses, and Student Research

Resource allocation is an evolving part of many Cloud computing and data center management problems. For infrastructure as a service (IaaS) in the Cloud, the Cloud service provider allocates virtual machines (VMs) to the customers with required CPU, memory and disk configurations. In addition to the computing infrastructures, the bandwidth resources would also be allocated to customers for data transmission between reserved VMs. In the near future, users may also want to reserve multiple virtual data centers (VDCs) to construct their own virtual Cloud, which could be called data center as a service (DCaaS). For these two types of services, …


Towards Building An Intelligent Integrated Multi-Mode Time Diary Survey Framework, Hariharan Arunachalam May 2016

Towards Building An Intelligent Integrated Multi-Mode Time Diary Survey Framework, Hariharan Arunachalam

School of Computing: Dissertations, Theses, and Student Research

Enabling true responses is an important characteristic in surveys; where the responses are free from bias and satisficing. In this thesis, we examine the current state of surveys, briefly touching upon questionnaire surveys, and then on time diary surveys (TDS). TDS are open-ended conversational surveys of a free-form nature with both, the interviewer and the respondent, playing a part in its progress and successful completion. With limited research available on how intelligent and assistive components can affect TDS respondents, we explore ways in which intelligent systems such as Computer Adaptive Testing, Intelligent Tutoring Systems, Recommender Systems, and Decision Support Systems …


Experimental Assessment Of Mouse Sociability Using An Automated Image Processing Approach, Frency Varghese, Jessica A. Burket, Andrew D. Benson, Stephen I. Deutsch, Christian W. Zemlin May 2016

Experimental Assessment Of Mouse Sociability Using An Automated Image Processing Approach, Frency Varghese, Jessica A. Burket, Andrew D. Benson, Stephen I. Deutsch, Christian W. Zemlin

Electrical & Computer Engineering Faculty Publications

Mouse is the preferred model organism for testing drugs designed to increase sociability. We present a method to quantify mouse sociability in which the test mouse is placed in a standardized apparatus and relevant behaviors are assessed in three different sessions (called session I, II, and III). The apparatus has three compartments (see Figure 1), the left and right compartments contain an inverted cup which can house a mouse (called “stimulus mouse”). In session I, the test mouse is placed in the cage and its mobility is characterized by the number of transitions made between compartments. In session II, a …


Maximization Of The Annual Energy Production Of Wind Power Plants By Optimization Of Layout And Yaw-Based Wake Control, Pieter Gebraad, Jared Thomas, Andrew Ning, Paul Fleming, Katherine Dykes May 2016

Maximization Of The Annual Energy Production Of Wind Power Plants By Optimization Of Layout And Yaw-Based Wake Control, Pieter Gebraad, Jared Thomas, Andrew Ning, Paul Fleming, Katherine Dykes

Faculty Publications

This paper presents a wind plant modeling and optimization tool that enables the maximization of wind plant annual energy production (AEP) using yaw-based wake steering control and layout changes. In order to make predictions of wind plant AEP, necessary extensions of the original wind plant wake interaction model include the coupling with a detailed rotor model and a control policy for turbine blade pitch and rotor speed. This coupling allows the prediction of power production with wake effects throughout a range of wind speeds. Results of an optimization study on a wind plant based on the Princess Amalia Wind Park …


Use Of Response Surfaces In The Design Of A Simple Step Stress Accelerated Test Plan, Alexander H. Wong May 2016

Use Of Response Surfaces In The Design Of A Simple Step Stress Accelerated Test Plan, Alexander H. Wong

Graduate Theses and Dissertations

In designing accelerated testing plans, cost is a factor that is missing in much of the literature. This paper explicits considers cost by developing an optimization model with the objective to minimize costs for a simple step stress accelerated test plan. Two methodologies are employed. One is an optimization approach in which an attempt is made to quantify the behavior of a series-parallel hardware system over all stages of testing using a response surface, and then an optimization model is used to determine the settings for stresses and failure mode modifications for all stages of testing prior to the start …


Genotoxicity Of Graphene In Escherichia Coli, Ananya Sharma May 2016

Genotoxicity Of Graphene In Escherichia Coli, Ananya Sharma

Graduate Theses and Dissertations

Rapid advances in nanotechnology necessitate assessment of the safety of nanomaterials in the resulting products and applications. One key nanomaterial attracting much interest in many areas of science and technology is graphene. Graphene is a one atom thick carbon allotrope arranged in a two-dimensional honeycomb lattice. In addition to being extremely thin, graphene has several extraordinary physical properties such as its exceptional mechanical strength, thermal stability, and high electrical conductivity. Graphene itself is relatively chemically inert and therefore pristine graphene must undergo a process called functionalization, which is combination of chemical and physical treatments that change the properties of graphene, …


A Tabu Search, Augment-Merge Heuristic To Solve The Stochastic Location Arc Routing Problem, Tiffany L. Yang May 2016

A Tabu Search, Augment-Merge Heuristic To Solve The Stochastic Location Arc Routing Problem, Tiffany L. Yang

Graduate Theses and Dissertations

The location arc routing problem (LARP) is a network optimization problem combining strategic facility location decisions and tactical or operational vehicle routing decisions for customer demand located on arcs of a network. The LARP seeks to locate facilities, or depots, and create vehicle delivery routes to minimize costs. The total cost is comprised of three components: fixed facility locations costs, fixed route creation (or vehicle acquisition) costs, and variable arc traversal costs. The applications of the LARP are varied and often include public services such as mail delivery, garbage collection, and street sweeping. In all of these applications, the magnitude …


Wireless Voice Amplification Device For Weak Patients, Daniel Alexander Johnson May 2016

Wireless Voice Amplification Device For Weak Patients, Daniel Alexander Johnson

Honors Theses

Abstract – One problem that nurses and doctors face when treating a very weak patient is difficulty of communication. Sometimes patients become so weak that they are barely able to speak above a whisper without completely exerting themselves. Often nurses will have to put their ear directly in front of a patient’s mouth in order to hear what the patient is saying over the ambient noise in a hospital room. This becomes an even bigger problem when several patients are together in a single room and the ambient noise levels rise. One way to solve this problem would be to …


Direct Band Gap Gallium Antimonide Phosphide (Gasbxp1-X) For Solar Fuels., Harry Benjamin Russell May 2016

Direct Band Gap Gallium Antimonide Phosphide (Gasbxp1-X) For Solar Fuels., Harry Benjamin Russell

Electronic Theses and Dissertations

Photoelectrochemical water splitting has been identified as a promising route for achieving sustainable energy future. However, semiconductor materials with the appropriate optical, electrical and electrochemical properties have yet to be discovered. In search of an appropriate semiconductor to fill this gap, GaSbP, a semiconductor never tested for PEC performance is proposed here and investigated. Density functional theory (DFT+U) techniques were utilized to predict band gap and band edge energetics for GaSbP alloys with low amount of antimony. The overall objective of this dissertation is to understand the suitability of GaSbxP1-x alloys for photoelectrochemical water splitting application. Specifically, …


Production And Inventory Control In Complex Production Systems Using Approximate Dynamic Programming., Han Wu May 2016

Production And Inventory Control In Complex Production Systems Using Approximate Dynamic Programming., Han Wu

Electronic Theses and Dissertations

Production systems focus not only on providing enough product to supply the market, but also on delivering the right product at the right price, while lowering the cost during the production process. The dynamics and uncertainties of modern production systems and the requirements of fast response often make its design and operation very complex. Thus, analytical models, such as those involving the use of dynamic programming, may fail to generate an optimal control policy for modern production systems. Modern production systems are often in possession of the features that allow them to produce various types of product through multiple working …


Green Logistic Network Design : Intermodal Transportation Planning And Vehicle Routing Problems., Xiaoren Duan May 2016

Green Logistic Network Design : Intermodal Transportation Planning And Vehicle Routing Problems., Xiaoren Duan

Electronic Theses and Dissertations

Due to earth's climate change and global warming, environmental consideration in the design of logistic systems is accelerating in recent years. In this research we aim to design an efficient and environmentally friendly logistical system to satisfy both government and carriers. In particular, we considered three problems in this dissertation: intermodal network design, deterministic green vehicle routing problem and stochastic green vehicle routing problem. The first problem aims to design an economic and efficient intermodal network including three transportation modes: railway, highway and inland waterway. The intent of this problem is to increase the utilization percentage of waterway system in …


Maximizing Orc Performance With Optimal Match Of Working Fluid With System Design, Kirtipal Barse, Michael Mann May 2016

Maximizing Orc Performance With Optimal Match Of Working Fluid With System Design, Kirtipal Barse, Michael Mann

Chemical Engineering Faculty Publications

This article compares constrained system design to non-constrained system design for the basic Organic Rankine Cycle (ORC). The 12 working fluids studied include eight dry-type, three isentropic, and one wet-type fluids. The ORC model was developed using Aspen HYSYS® and validated with data obtained from the literature. The constrained design compared the performance of working fluids for a fixed heat exchanger and turbine configuration. A non-constrained design was studied by altering the design specifications for the heat exchangers and turbine to match the working fluid. An energy and exergy analysis was performed using first and second law efficiency. The exergy …


Effects Of Noise, Reverberation And Foreign Accent On Native And Non-Native Listeners’ Performance Of English Speech Comprehension, Zhao Ellen Peng, Lily M. Wang May 2016

Effects Of Noise, Reverberation And Foreign Accent On Native And Non-Native Listeners’ Performance Of English Speech Comprehension, Zhao Ellen Peng, Lily M. Wang

Durham School of Architectural Engineering and Construction: Faculty Publications

A large number of non-native English speakers may be found in American classrooms, both as listeners and talkers. Little is known about how this population comprehends speech in realistic adverse acoustical conditions. A study was conducted to investigate the effects of background noise level (BNL), reverberation time (RT), and talker foreign accent on native and non-native listeners' speech comprehension, while controlling for English language abilities. A total of 115 adult listeners completed comprehension tasks under 15 acoustic conditions: three BNLs (RC-30, RC-40, and RC-50) and five RTs (from 0.4 to 1.2 s). Fifty-six listeners were tested with speech from native …


Design Of Three-Dimensional Near-Zero Refractive Index Metamaterials, David Flores Iii May 2016

Design Of Three-Dimensional Near-Zero Refractive Index Metamaterials, David Flores Iii

Theses and Dissertations

Near-zero refractive index metamaterials exhibit remarkable electromagnetic properties which can and will be applied in the near future. From the known methods of achieving near-zero refractive index, this work primarily focuses on the design of 3D metamaterials whose permittivity and permeability are both close to zero while maintaining relatively low loss factor. The design of the metamaterials is based on the chiral shape “omega” and designed to weave periodically as a fishnet. Theoretical analysis, computer modeling and simulation are steps taken in the design of metamaterials. A computational tool based on the robust method for effective parameter extraction is successfully …


Design Of A Folding V-Scraper With Roller For Orchard Applications, Chase Ulrich May 2016

Design Of A Folding V-Scraper With Roller For Orchard Applications, Chase Ulrich

BioResource and Agricultural Engineering

This senior project discusses the design of a folding 15 ft. wide leveler for orchard use. This design utilized a category 2 three-point hitch to connect the implement to a tractor. The folding mechanism uses the tractors hydraulic system to actuate the folding movement using hydraulic cylinders. The blades, when wings in operational position, are rigid with one another after some assembly. When the implement is folded the width is reduced to nine feet.


Design, Construction, And Evaluation Of Off-Road Rock Sliders, Jake M. Freedman May 2016

Design, Construction, And Evaluation Of Off-Road Rock Sliders, Jake M. Freedman

BioResource and Agricultural Engineering

This senior project describes the design, fabrication, and evaluation of off-road rock sliders which can be used with Toyota Tacoma trucks of model year 2005-2012. Rock sliders are a form of trail armor and are a common aftermarket addition to trucks that are often used in off-road conditions. Rock sliders, in their simplest form, consist of a steel beam (either tubular or rectangular) that runs underneath the doors of the vehicle providing protection to the undercarriage, rocker panels, and doors as well as reducing the likelihood of becoming stuck or “high-centered” on the underside of the vehicle. The sliders will …


Agroecosystem And Ecosystem Resiliency To Extreme Hydrometeorological And Climate Events, Katherine M. Werner May 2016

Agroecosystem And Ecosystem Resiliency To Extreme Hydrometeorological And Climate Events, Katherine M. Werner

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

The purpose of this study was to understand how a large-scale representation of agroecosystems and ecosystems respond to extreme hydrometeorological and climate extreme events (EHCE) within the Platte River Basin. The ability for agroecosystems and ecosystems to adapt to a changing and variable climate is vital for global water, energy, and food security. Two model experiments were performed, the first with a time span from 2000 to 2013 in which a dynamic leaf area index (LAI) MODIS15A2 product was implemented. The second experiment ran from 1950 through 2013 used a climatological fixed seasonal cycle calculated as the average from the …


Review And Experimental Investigation Of Phase Change Material Use In Buildings, Russell W. Locetta May 2016

Review And Experimental Investigation Of Phase Change Material Use In Buildings, Russell W. Locetta

Mechanical Engineering Undergraduate Honors Theses

This paper presents an overview of phase change materials (PCM) and their properties along with a review of relevant studies conducted in the past several years over phase change materials. An experiment is conducted to examine the differences between external building walls with and without bio-based phase change materials. In addition, the length of time BioPCM requires to completely change phase is examined from the data. Based on the data, the internal wall temperature of a home can be reduced by approximately 2 F. Additionally, a theoretical case study is presented and it is concluded that with the use of …


Droplet Generation At Megahertz Frequencies, John C. Miers May 2016

Droplet Generation At Megahertz Frequencies, John C. Miers

Mechanical Engineering Undergraduate Honors Theses

Droplet formation has been a fascinating subject to scientists for centuries due to its natural beauty and importance to both scientific and industrial applications, such as inkjet printing, reagent deposition, and spray cooling. However, the droplet generation frequency of common drop-on-demand jetting techniques is mostly limited to ~10 kHz. This paper presents an investigation of the possibility of jetting at megahertz frequencies in order to boost the productivity of drop-on-demand material deposition by ~100 times. The focus of this paper is to understand the limitations of generating droplets at a megahertz frequency and to explore possible solutions for overcoming these …


The Agricultural Growth And Malting Production Of Barley Grains In Northeast Tennessee And Southwest Virginia, Mark Evans Patton Mr. May 2016

The Agricultural Growth And Malting Production Of Barley Grains In Northeast Tennessee And Southwest Virginia, Mark Evans Patton Mr.

Electronic Theses and Dissertations

The purpose of this study is to explore the history and production processes of beer and examines the components that contribute to its brewing. The narrative will provide a timeline of the processes that are required to create the product of beer beginning with the agricultural products and following the brewing processes that result in beer as the finished product. I will also examine the business of agriculture and grain processing and will provide some historical perspectives of grain, beer, and malting. I will also consider whether the growing, processing, and malting of grains in the East Tennessee and Southwest …


Finite Element Modeling Of Shallowly Embedded Connections To Characterize Rotational Stiffness, Trevor Alexander Jones May 2016

Finite Element Modeling Of Shallowly Embedded Connections To Characterize Rotational Stiffness, Trevor Alexander Jones

Theses and Dissertations

Finite element models were created in Abaqus 6.14 to characterize the rotational stiffness of shallowly embedded column-foundation connections. Scripts were programmed to automate the model generation process and allow study of multiple independent variables, including embedment length, column size, baseplate geometry, concrete modulus, column orientation, cantilever height, and applied axial load. Three different connection types were investigated: a tied or one part model; a contact-based model; and a cohesive-zone based model. Cohesive-zone modeling was found to give the most accurate results. Agreement with previous experimental data was obtained to within 27%. Baseplate geometry was found to affect connection stiffness significantly, …