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2016

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Articles 4921 - 4950 of 9607

Full-Text Articles in Engineering

Using Value-Focused Thinking For Engineered Resilient Systems, Colin A. Small May 2016

Using Value-Focused Thinking For Engineered Resilient Systems, Colin A. Small

Industrial Engineering Undergraduate Honors Theses

The DoD needs their systems to be resilient in the face of an ever changing world. To increase resilience in future systems the DoD has created a program called Engineered Resilient Systems. Resilience can be broken down into two parts, mission and platform resilience. Mission resilience is the ability of a system to repel, resist, absorb, and recover from environments and threats that occur on planned missions. Platform resilience is the ability of a system platform to adapt to new missions and new threats.

The University of Arkansas department of Industrial Engineering is working for the ERS program researching resilience. …


Histogram Of Oriented Phase (Hop): A New Descriptor Based On Phase Congruency, Hussin Ragb, Vijayan K. Asari May 2016

Histogram Of Oriented Phase (Hop): A New Descriptor Based On Phase Congruency, Hussin Ragb, Vijayan K. Asari

Electrical and Computer Engineering Faculty Publications

In this paper we present a low level image descriptor called Histogram of Oriented Phase based on phase congruency concept and the Principal Component Analysis (PCA). Since the phase of the signal conveys more information regarding signal structure than the magnitude, the proposed descriptor can precisely identify and localize image features over the gradient based techniques, especially in the regions affected by illumination changes. The proposed features can be formed by extracting the phase congruency information for each pixel in the image with respect to its neighborhood. Histograms of the phase congruency values of the local regions in the image …


Asset Management Model For An Industrial Process Automations System In The Chemical Engineering Unit Operations Laboratory At Rose-Hulman Institute Of Technology, Megan Elaine Liebman May 2016

Asset Management Model For An Industrial Process Automations System In The Chemical Engineering Unit Operations Laboratory At Rose-Hulman Institute Of Technology, Megan Elaine Liebman

Graduate Theses - Chemical Engineering

In the Chemical Engineering curriculum, the Unit Operations (UO) Laboratory is recognized as the place where hands-on exposure to industrial practices occurs. Students not only examine fundamental engineering principles, but also gain knowledge of the intricacies of modern control technology. The UO Laboratory at Rose-Hulman Institute of Technology houses an industrial state-of-the-art distributed control system, which operates eleven large-scale experiments and interfaces with approximately two hundred process instruments. The size and complexity of the distributed control system and its associated equipment have grown over the past ten years and have reached a point where a systematic asset management approach is …


Development Of A User Interface To Communicate With Virtual Delta Robot Using Modbus Tcp/Ip And C#, Armin Maraghehmoghaddam May 2016

Development Of A User Interface To Communicate With Virtual Delta Robot Using Modbus Tcp/Ip And C#, Armin Maraghehmoghaddam

Morehead State Theses and Dissertations

A thesis presented to the faculty of the College of Business and Technology at Morehead State University in partial fulfillment of the requirements for the Degree of Master of Science by Armin Maraghehmoghaddam on May 1, 2016.


Smart Gate Driver Design For Silicon (Si) Igbts And Silicon-Carbide (Sic) Mosfets, Abdulaziz Alghanem May 2016

Smart Gate Driver Design For Silicon (Si) Igbts And Silicon-Carbide (Sic) Mosfets, Abdulaziz Alghanem

Electrical Engineering Undergraduate Honors Theses

The design of an efficient and smart gate driver for a Si IGBT and SiC MOSFET is addressed in thesis. First, the main IGBT parameters are evaluated thoroughly in order to understand their effects in the design of the gate driver. All known consequences of previously designed gate drivers are studied in order to achieve an optimum gate driver. As a result of this assessment, the designer is able to determine whether adding or removing components from the gate driver circuit are beneficial or not. Then, exhaustive research is done to identify suitable integrated circuits to use for the power …


A Study On The Effects Of Example Familiarity And Modality On Design Fixation, Vimal Viswanathan, Megan Tomko, Julie Linsey May 2016

A Study On The Effects Of Example Familiarity And Modality On Design Fixation, Vimal Viswanathan, Megan Tomko, Julie Linsey

Faculty Publications, Mechanical Engineering

Design fixation is a factor that negatively influences the generation of novel design concepts (Jansson & Smith, 1991). When designers fixate, they tend to reproduce example features or features from their initial ideas. In order to mitigate design fixation, it is crucial to identify the factors that influence the extent of design fixation. This paper investigates two such factors: the modality of examples and the familiarity of designers with the example features. To investigate this, an experiment is conducted with mechanical engineering students who were asked to generate ideas to solve a peanut sheller design problem. The students generated ideas …


Design And Implementation Of A Controller For A Beaglebone Quadcopter, Peter Olejnik May 2016

Design And Implementation Of A Controller For A Beaglebone Quadcopter, Peter Olejnik

Graduate Theses - Mechanical Engineering

Unmanned aerial vehicles are quickly becoming a significant and permanent feature in today's world of aviation. Amongst the various types of UAVs, a popular type is the quadcopter. Also referred to as a quadrotor, this rotor craft's defining feature is that it has four propellers. While its use is common in the hobbyist community, this aircraft's use within industry is blooming.

Presented are the efforts to design and implement a controller for a BeagleBone based quadcopter. As part of this effort, characteristics of the quadcopter were experimentally determined. These characteristics consist of physical properties of the quadcopter, such as the …


Design Of Smartseat Car Seat Safety System To Prevent Child Vehicular Heat Stroke, Alexis D. Lamott May 2016

Design Of Smartseat Car Seat Safety System To Prevent Child Vehicular Heat Stroke, Alexis D. Lamott

Electrical Engineering Undergraduate Honors Theses

Child vehicular heatstroke deaths continue to be a preventable accident seen yearly. As such, a proposed safety system has been designed to monitor environmental temperatures and weight in an infant seat, to alert guardians that a young child is at risk of child vehicular heatstroke death or serious heatstroke related injury. The SmartSeat system is comprised of three separate printed circuit boards that work in unison to form the overall system.


Inferring Intrinsic Beliefs Of Digital Images Using A Deep Autoencoder, Seok H. Lee May 2016

Inferring Intrinsic Beliefs Of Digital Images Using A Deep Autoencoder, Seok H. Lee

Computer Science and Computer Engineering Undergraduate Honors Theses

Training a system of artificial neural networks on digital images is a big challenge. Often times digital images contain a large amount of information and values for artificial neural networks to understand. In this work, the inference model is proposed in order to absolve this problem. The inference model is composed of a parameterized autoencoder that endures the loss of information caused by the rescaling of images and transition model that predicts the effect of an action on the observation. To test the inference model, the images of a moving robotic arm were given as the data set. The inference …


Design Of Processing Circuitry For An Rf Energy Harvester, Brett Schauwecker May 2016

Design Of Processing Circuitry For An Rf Energy Harvester, Brett Schauwecker

Electrical Engineering Undergraduate Honors Theses

Significant advancements in technology and the use of low power sensors in both commercial and industrial applications have made it essential to develop wireless solutions for low power devices. Once such solution, which has generated attention in university and R&D environments, is radio frequency (RF) energy harvesting. RF energy harvesting seeks to capture ambient RF energy by means of an antenna and convert this energy to useable DC power. The presence of ambient RF energy in the environment is a result of numerous high-frequency technologies including Wi-Fi, cell phones, microwave ovens, and radio broadcasting, as well as many others. The …


Optical Analysis And Fabrication Of Micro And Nanoscale Plasmonically Enhanced Devices, Avery M. Hill May 2016

Optical Analysis And Fabrication Of Micro And Nanoscale Plasmonically Enhanced Devices, Avery M. Hill

Physics Undergraduate Honors Theses

Plasmonic nanostructures have been shown to act as optical antennas that enhance optical devices due to their ability to focus light below the diffraction limit of light and enhance the intensity of the incident light. This study focuses on computational electromagnetic (CEM) analysis of two devices: 1) GaAs photodetectors with Au interdigital electrodes and 2) Au thin-film microstructures. Experiments showed that the photoresponse of the interdigital photodetectors depend greatly on the electrode gap and the polarization of the incident light. Smaller electrode gap and transverse polarization give rise to a larger photoresponse. It was also shown that the response from …


Inspire E-News 05 2016, College Of Engineering And Applied Sciences May 2016

Inspire E-News 05 2016, College Of Engineering And Applied Sciences

College of Engineering and Applied Sciences News

  • Matthew Baird receives NASA Space Technology Research Fellowship
  • Girls Scouts are “Engineers for a Day”
  • Consumers Energy planting “solar garden” on Parkview campus


Assessing The Advantages Of Using Square Wave Signals For Particle Trapping In Carbon-Electrode Dielectrophoresis, Guillermo Contreras-Dávila, Jose I. Gomez-Quiñones, Victor H. Pérez-González, Rodrigo Martinez-Duarte May 2016

Assessing The Advantages Of Using Square Wave Signals For Particle Trapping In Carbon-Electrode Dielectrophoresis, Guillermo Contreras-Dávila, Jose I. Gomez-Quiñones, Victor H. Pérez-González, Rodrigo Martinez-Duarte

Publications

Here we present an improvement on the trapping efficiency of 3D carbon electrode Dielectrophoresis (carbonDEP) by using alternative signal geometries to the more traditional sine used to stimulate the electrodes. In particular, a square waveform is used. Theoretical analysis was based on the Root Mean Square (RMS) values and the Fourier Series Expansion of these signals. Computational modeling was performed to calculate the DEP force generated by the two signal waveforms and allowed for direct comparison. The trapping efficiency between square and sine signals was then determined experimentally. Given the same experiment characteristics, the use of square signals allows for …


Synthesis Of Tungsten Carbide From Bacterial Cellulose, Monsur Islam, Rodrigo Martinez-Duarte May 2016

Synthesis Of Tungsten Carbide From Bacterial Cellulose, Monsur Islam, Rodrigo Martinez-Duarte

Publications

Here we present preliminary experiments for the synthesis of carbide material using bacterial cellulose as carbon source. We used bacteria cellulose available as Nata de Coco and infiltrated it with tungsten trioxide (WO3) nanoparticles. This composite was heat treated at 1300 °C in nitrogen atmosphere. The XRD pattern confirms the synthesis of tungsten carbide (WC) in the carbonaceous material, though a significant amount of metallic tungsten remained unreacted. SEM images shows that WC particles are present only at the surface of the carbon, which may be a consequence of improper infiltration or collapse of carbon matrix during heat …


Synthesis Of Titanium Oxycarbide Through Carbothermal Reduction Of Titanium Dioxide Nanoparticles And Renewable Biopolymers, Joshua Paul Flach, Paulo Henrique Figuereido De Lima, Joshua Craig Sparks, Monsur Islam, Rodrigo Martinez-Duarte May 2016

Synthesis Of Titanium Oxycarbide Through Carbothermal Reduction Of Titanium Dioxide Nanoparticles And Renewable Biopolymers, Joshua Paul Flach, Paulo Henrique Figuereido De Lima, Joshua Craig Sparks, Monsur Islam, Rodrigo Martinez-Duarte

Publications

The goal of this is study is to explore the feasibility of a sustainable method of titanium oxycarbide synthesis through carbothermal reduction of a biopolymer composite. The reaction was studied at different temperatures in vacuum environments and at multiple TiO2:C ratios in order to determine how these parameters affect the formation of titanium oxycarbide. The results indicate that both the heat treatment and the carbon ratios have a significant impact on the O/C ratio, and therefore, molecular composition and crystal structure of the titanium oxycarbide. The use of renewable biopolymers as a carbon source in the synthesis of …


Towards Additive Manufacturing Of Tungsten Carbide Using Renewable Resources, Monsur Islam, Rodrigo Martinez-Duarte May 2016

Towards Additive Manufacturing Of Tungsten Carbide Using Renewable Resources, Monsur Islam, Rodrigo Martinez-Duarte

Publications

Here we present preliminary results towards additive manufacturing of carbides. A biopolymer-metal oxide gel composite composed of iota-carrageenan, chitin and tungsten trioxide (WO3) was shaped and heat treated in order to obtain carbide structures. Upon heat treatment of this composite above 900 °C, a porous structure of tungsten carbide (WC) was obtained. The synthesis mechanism of WC was estimated using the result from XRD characterization. The synthesized WC was characterized with SEM, TEM and nitrogen absorption-desorption to investigate the morphology, particle size and pore size distribution. The carbonaceous materials retained the original shape. The ongoing work is on …


3d Carbon-Electrode Dielectrophoresis For Enrichment Of A Small Cell Population From A Large Sample Volume, Monsur Islam, Rucha Natu, Maria Fernanda Larraga-Martinez, Guillermo Contreras-Dávila, Rodrigo Martinez-Duarte May 2016

3d Carbon-Electrode Dielectrophoresis For Enrichment Of A Small Cell Population From A Large Sample Volume, Monsur Islam, Rucha Natu, Maria Fernanda Larraga-Martinez, Guillermo Contreras-Dávila, Rodrigo Martinez-Duarte

Publications

Isolation and enrichment of cells from a diluted sample is necessary for different clinical applications. Here we have demonstrated the use of 3D carbon electrode dielectrophoresis (DEP) to process a diluted yeast sample featuring concentration as low as 102 cells/ml. The yeast cells in the sample were first trapped on carbon electrodes by implementing positive DEP force and then released and concentrated in a small volume of clean buffer. The maximum limit of the cell trapping for our device was found to be around 4000 cells. Using 10 µl/min, an enrichment of 154.2 ± 23.7 folds was achieved, where sample …


Micro-Raman Investigation Of Residual Stresses In Sic/Sic Composites, Kaitlin Kollins May 2016

Micro-Raman Investigation Of Residual Stresses In Sic/Sic Composites, Kaitlin Kollins

The University Honors Program

Ceramic Matrix Composites (CMCs) are being developed for use in extreme operating conditions. Specifically, there is interest to replace superalloys with Silicon-Carbide/Silicon-Carbide (SiC/SiC) CMCs in the hot section of gas turbine engines because of their lower densities, high temperature performance, and oxidation resistance. Due to the high temperature processing conditions of SiC/SiC CMCs, there are thermal residual stresses inherent to the material. This study focused on using micro-Raman Spectroscopy on as manufactured SiC/SiC CMCs to measure and investigate the residual stresses within a fiber and the matrix material. Following the silicon Raman active mode at 520 cm-1 and the SiC …


Analysis Of Bridge Deck Sections By Pseudo-Compressibility Method Based On Fdm And Les: Improving Performance Through Implementation Of Parallel Computing, Blandine Therese Mbianda Kemayou May 2016

Analysis Of Bridge Deck Sections By Pseudo-Compressibility Method Based On Fdm And Les: Improving Performance Through Implementation Of Parallel Computing, Blandine Therese Mbianda Kemayou

Graduate Theses and Dissertations

The incidence of wind on bridges produces static and dynamic loading that must be adequately addressed when designing bridges. Dynamic loading is the primary concern, as the amplitude of the structures response to the applied loading may be greatly amplified. Ideally, the bridge's properties should be designed to avoid dynamic loading. Previous investigations of wind loading on bridges consisted of measuring forces produced on scaled models of bridges within wind tunnels. However, these wind tunnel tests are costly and time consuming due to cost to fabricate and instrument the bridge cross sections. Recent advancements in computational power of computers allow …


Quantification And Characterization Of Fracture Resistance In Asphalt Concrete Based On R-Curve Method, Shu Yang May 2016

Quantification And Characterization Of Fracture Resistance In Asphalt Concrete Based On R-Curve Method, Shu Yang

Graduate Theses and Dissertations

The application of fracture energy is widely applied in the evaluation of cracking in the laboratory for asphalt concrete. However, this single number does not provide information on the characterization of the initiation and propagation of cracks. The Resistance Curve method, or R-Curve, is widely applied in characterizing various materials including, but not limited to, metal, polymer, rock, and composite. This research R-Curve method introduces asphalt concrete through a stepwise approach. First, in chapter one, there is a literature review of the history of fracture mechanics, fracture research in asphalt concrete, and an examination of the role of R-Curve application …


Exploring The Black Space Of Compressive And Shear Modulus, Airam Marlee Morales Vega May 2016

Exploring The Black Space Of Compressive And Shear Modulus, Airam Marlee Morales Vega

Graduate Theses and Dissertations

Uniaxial dynamic modulus is a standard test used to determine the viscoelastic behavior of asphalt pavement materials, with the standard analysis generating a Master Curve. One alternative to the master curve approach is a Black Space diagram, which is a rheological plot that can delineate either dynamic modulus |E*| or shear modulus |G*| vs. phase angle (δ). In this study, four asphalt binders were tested with one aggregate blend. One of these four binders was unmodified and the other three were modified with polymers and acids. Additionally, Polyphosphoric acid (PPA) is compared to the more traditional SBS polymer modification. PPA …


Impact Of Extreme Summer Temperatures On Bridge Structures, Ryan Hagedorn May 2016

Impact Of Extreme Summer Temperatures On Bridge Structures, Ryan Hagedorn

Graduate Theses and Dissertations

Climate change and its effect on weather in the United States is a well-documented phenomenon. In particular, extreme heat waves have become more intense, more frequent, and longer lasting, especially in the southern United States. As with much of America’s transportation infrastructure, prestressed concrete bridge girders experience the effects of these heat waves. Uneven heating of optimized bridge girder sections results in large non-linear temperature gradients. In this study, temperature was monitored in three different AASHTO I-girders to determine the vertical and transverse temperature gradients in a pre-deck placement condition. It was determined that the current design standard, which uses …


Nanofiltration Rejection Of Contaminants Of Emerging Concern From Municipal Water Resource Recovery Facility Secondary Effluents For Potable Reuse Applications, Steven Michael Jones May 2016

Nanofiltration Rejection Of Contaminants Of Emerging Concern From Municipal Water Resource Recovery Facility Secondary Effluents For Potable Reuse Applications, Steven Michael Jones

Graduate Theses and Dissertations

As reuse of municipal water resource recovery facility (WRRF) effluent becomes vital to augment diminishing fresh drinking water resources, concern exists that conventional barriers may prove deficient and the upcycling of contaminants of emerging concern (CECs) could prove harmful to human health and aquatic species if more effective and robust treatment barriers are not in place.

There are no federal Safe Drinking Water Act (SDWA) regulations in place specifically for direct potable reuse (DPR) of WRRF effluent. Out of necessity, some states are developing their own DPR reuse regulations. Currently, reverse osmosis (RO) is the default full advanced treatment (FAT) …


Structural Identification Of An Elevated Water Tower, James Thomas Norris May 2016

Structural Identification Of An Elevated Water Tower, James Thomas Norris

Graduate Theses and Dissertations

Elevated water tanks are generally located at higher elevations within a particular geographic area. The location and height of these structures often makes them desirable for installing wireless and cellular communications antennas. The impact of this practice on the long-term serviceability performance of the primary structure is not clear and could be an important consideration deserving further analysis. This paper presents a case study of an elevated water tank that was motivated by this particular consideration. The structure had been retrofitted with cellular antennas during its service and later experienced fatigue cracking at the fill pipe-tank interface. The owner wished …


Evaluation Of Poisson’S Ratio Of Asphalt Concrete, Elvis Alexander Castillo Camarena May 2016

Evaluation Of Poisson’S Ratio Of Asphalt Concrete, Elvis Alexander Castillo Camarena

Graduate Theses and Dissertations

Poisson´s ratio can be defined as the negative ratio of strains perpendicular to the load direction to the strains parallel to the loading direction. If elastic or viscoelastic models are used, Poisson´s ratio, together with elastic modulus, is a main input used to predict distresses in flexible pavement structures such as rutting and cracking. In asphalt concrete, Poisson’s ratio is commonly measured using two different testing configurations: indirect tension (IDT) and uniaxial. However, results from these two testing configuration can potentially have differences. Design methodologies such as the Mechanistic Empirical Design Guide (MEPDG, now PavementME) have been shown to be …


Field Observations And Computer Modeling Of Tornado-Terrain Interaction And Its Effects On Tornado Damage And Path, Nawfal Shihab Ahmed May 2016

Field Observations And Computer Modeling Of Tornado-Terrain Interaction And Its Effects On Tornado Damage And Path, Nawfal Shihab Ahmed

Graduate Theses and Dissertations

Tornado forces on structures have been a research focus for the past decades, and some comparisons have been made to distinguish between straight boundary layer (SBL) wind and tornado wind forces on specific structures. However, very little attention has been paid to terrain effects on tornado damage and path. Available damage investigation data for four tornado locations (Joplin-2011, Tuscaloosa-2011, Parish-2011 and Mayflower-2014) is utilized to explore terrain effects on tornado damage and path. Google Earth, site visits and aerial images are employed to study the influence of terrain on an extent of damage and path variation. Additionally, a three dimensional …


Development Of The Masw Method For Pavement Evaluation, Benjamin J. Davis May 2016

Development Of The Masw Method For Pavement Evaluation, Benjamin J. Davis

Graduate Theses and Dissertations

The purpose of this research is to establish a recommended procedure for performing multichannel analysis of surface waves (MASW) on pavements as well as evaluating the ability of MASW to detect a change in shear wave velocity as damage in concrete increases. The tests for establishing a recommended procedure for performing MASW on pavements was conducted at five sites at the University of Arkansas Engineering Research Center in Fayetteville, Arkansas. The five sites consisted of three materials: asphalt, concrete, and soil (two sites were on asphalt, two were on concrete, and one was on soil). The methods evaluated at these …


Coercivity Enhancement And Gamma Phase Avoidance Of Alnico Alloys, Li Zhang May 2016

Coercivity Enhancement And Gamma Phase Avoidance Of Alnico Alloys, Li Zhang

Department of Engineering Mechanics: Dissertations, Theses, and Student Research

The promotion of social progress requires greater levels of energy efficiency, quality and productivity. However, these developments usually come at the cost of the environment. Green technologies such as electric vehicles, wind turbine and solar panels are ironically overshadowed by supply limitations and high prices of rare earth elements. Therefore, it is important to find alternative materials to replace those that contain critical elements. Alnico alloys show high magnetization, high Curie temperature (800°C) and good corrosion resistance, making it one of the best candidates to replace neodymium-based magnets used in electric vehicles.

In this thesis, methods controlling shape anisotropy and …


Shrinkage Analysis Of Carbon Micro Structures Derived From Su-8 Photoresist, Rucha Natu, Monsur Islam, Rodrigo Martinez-Duarte May 2016

Shrinkage Analysis Of Carbon Micro Structures Derived From Su-8 Photoresist, Rucha Natu, Monsur Islam, Rodrigo Martinez-Duarte

Publications

We present preliminary results for the analysis of shrinkage of 3D carbon posts obtained by the pyrolysis of SU-8 precursor structures, in a technique known as Carbon MEMS. Though the shrinkage in the carbon structures is highly reproducible, there is a strong dependence of this shrinkage on the initial dimensions of the SU-8 pillars. Our hypothesis is that the shrinkage depends upon the area available for degassing during carbonization. In this work, this idea is used to analyze shrinkage in cylindrical pillars. The results obtained are studied based on the ratio of lateral and top surface area available for degassing …


Shear Behavior Of High-Strength Self-Consolidating Concrete In Nebraska University Bridge Girders, Alex Griffin, John J. Myers May 2016

Shear Behavior Of High-Strength Self-Consolidating Concrete In Nebraska University Bridge Girders, Alex Griffin, John J. Myers

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Current reinforced and prestressed concrete design equations were developed for conventional concrete elements. Self-consolidating concrete (SCC) typically contains a lower coarse aggregate content and size than conventional concrete, which potentially hinders the aggregate interlock contribution to a concrete's shear strength. Thus, shear design equations must be verified with SCC mixtures. Two full-scale precast, prestressed concrete Nebraska University girders were tested to assess the shear behavior of high-strength SCC. Both girders were designed to permit two tests on each girder, both with and without shear reinforcement. Ultimate shear loads and crack patterns were documented and compared with code estimates, finite element …