Engineering Commons^™

Wideband Absorber Characterization Using Coaxial Airline And Electromagnetic Simulation, Ha Tran, Thanh Le, Branimir Pejcinovic

Student Research Symposium

With the increase in popularity of electronic devices especially the wireless devices, microwave absorber becomes more essential to reduce electromagnetic interference. A deep understanding of electromagnetic properties namely electric permittivity and magnetic permeability is required in order to fabricate, test and use microwave absorber. In this study, we focused on developing a procedure to parameterize material electromagnetic properties. We first extract material properties by placing samples inside an airline and taking measurements of scattering parameters matrix with a vector network analyzer. Air-line is the preferred transmission line medium since the traveling wave inside the airline is both TEM and confined. …

Toward Understanding Pu And Peou Of Technology Acceptance Model, Nayem Rahman

Student Research Symposium

Technology Acceptance Model (TAM) is considered one of the most popular models used in Information System (IS) research. Fred Davis developed this model as part of his doctoral research at MIT in 1986. Since then this model has been widely used in IS research and other disciplines. Two main components of TAM are Perceived Usefulness (PU) and Perceived Ease of Use (PEOU). This model allowed researchers to plug-in external factors to these two components. Researchers have used a variety of external factors to draw relationships between these two internal factors of TAM model. However, most of the research used these …

Business Model Innovation: Review Of The Concept, Importance, Classifications, And Elements, Ahmed Alibage, Mark Ahn

Student Research Symposium

The research trend on business models continues to surge, foreseeing them as the future blueprint to create and sustain competitive advantages, as well as the major driver that guides the strategic renovation efforts of businesses all over the world. In this research, we intensively review the literature on the business model regarding the concept emergence, theoretical background, definitions, importance, classifications, and the structure of the elements. Our interest is in gaining a better understanding of how to innovate a business model that can lead to create and sustaincompetitive advantages. Based on our findings, the literature to date lacks the systematic …

Alternative Depressor For Apatite Flotation, André Carlos Silva, Débora Nascimento Sousa, Diego Valentim Crescente Cara, Alex Malue Machado, Elenice Maria Schons Silva

Beneficiation of Phosphates VIII

The reality of the phosphate mines in the world has been changing. The reserves content has reduced over the years. As a consequence of this reduction, contaminants such as iron, silica and magnesium contained in phosphate rock concentrate are affecting the stability of the chemical plants, which compromises the rate of phosphate utilization and the quality of the products produced. In order to obtain a concentrate of phosphatic rocks of market acceptable quality (35% P₂O₅), the flotation process is the most suitable method for processing this. The present study aims to evaluate the potential of replacing …

The Surface Chemistry And Microflotation Of Xenotime And Depression Of Gangue Minerals, Corby Anderson, Yicheng Zhang

Beneficiation of Phosphates VIII

A pre-concentrated xenotime sample and four selected gangue minerals, ilmenite, zircon, schorl and staurolite were used in this project. Using Octano-hydroxamic acid as a collector, the surface chemistry was investigated through surface area measurements, zeta potential tests and adsorption density determinations. The results of adsorption studies were then correlated with microflotation tests conducted at room temperature in a Partridge-Smith cell. In this paper, the surface chemistry and microflotation behaviors are then discussed based on both lab observations and a literature review.

Further, because of their selective depressing power, sodium silicate and lignosulfonate have been widely used as depressants in rare-earth …

Using Two Alternative Vegetable Oil’S As Collector In Apatite Froth Flotation, André Carlos Silva, Elenice Maria Schons Silva, Alex Malue Machado, Diego Valentim Crescente Cara, Débora Nascimento Sousa

Beneficiation of Phosphates VIII

The Brazilian phosphate deposits are of igneous origin exhibiting a complex mineralogy where fluorapatite is the predominant mineralogical variety fron the apatite group, this deposits still contain carbonateapatite and hydroxyapatite associated with secondary phosphates, iron oxides (magnetite, goethite and limonite), micas and minerals bearing niobium, titanium and barium. The flotation process as a separation and enrichment of the acceptable levels by the P₂O₅ market (35%) is the most efficient. Brazilian mineral industries use synthetic collectors from international companies. Many of these oils were initially produced to sort out the demand for biodiesel production, with their market being …

Nitrogen And Weed Management In Transplanted Tomato In The Nigerian Forest-Savanna Transition Zone, J. A. Adigun, O. S. Daramola, O. R. Adeyemi, P. M. Olorunmaiye, O. A. Osipitan

Haskell Agricultural Laboratory (Northeast Research and Extension Center)

Weed infestation and inherent low soil fertility are among primary reasons for low yields of tomato in Nigeria. Field trials were carried out during the wet season of 2015 and 2016 to evaluate yield response of tomato to nitrogen (N) application and weed control methods in the forest-savanna transition zone of Abeokuta, Nigeria. Positive relationship exists between growth of weed species and increase in N application. Across the years of study, increase in N up to 90 kg/ha increased weed density by 11–25%, however, the increased N gave the transplanted tomato competitive advantage and thus enhanced weed smothering. Pre-transplant application …

Discussing The “Positive Utilities” Of Autonomous Vehicles: Will Travellers Really Use Their Time Productively?, Patrick A. Singleton

Civil and Environmental Engineering Faculty Publications

Autonomous vehicles (AVs) are expected to reshape travel behaviour and demand in part by enabling productive uses of travel time—a primary component of the “positive utility of travel” concept—thus reducing subjective values of travel time savings (VOT). Many studies from industry and academia have assumed significant increases in travel time use and reductions in VOT for AVs. In this position paper, I argue that AVs’ VOT impacts may be more modest than anticipated and derive from a different source. Vehicle designs and operations may limit activity engagement during travel, with AV users feeling more like car passengers than train riders. …

Experimental Validation Of External Load Effects For Micro-Contacts Under Low Frequency, Low Amplitude Alternating Current (Ac) Test Conditions, Protap Mahanta, Ronald A. Coutu Jr., Dushyant Tomer

Electrical and Computer Engineering Faculty Research and Publications

The use of micro-contacts has been demonstrated in various radio frequency (RF) applications. However, the premature failure of such devices under alternating current (AC) operations is still a hurdle to further development. In this work, modified gray scale lithography is performed to fabricate two types of gold–gold (Au–Au) micro-contacts: hemispherical-planar and hemispherical-2D pyramid. The performance of these devices was investigated under low frequency, low amplitude AC conditions with external circuit loads. A custom-made experimental setup which uses various load configurations, controls the frequency of the applied voltage and modifies the cycle rate of switch operation to obtain the contact resistance …

Verification And Validation Of Forces From Hippotherapy Rein Simulator, Sonia Sanchez

Graduate Theses - Biology & Biomedical Engineering

The thesis describes the redevelopment, testing, and validation of a rein training device intended to help riders learn to guide a horse during hippotherapy sessions. The thesis aims to validate and verify that the forces read by the redeveloped rein simulator were operant within ± 150 grams of the actual weight applied, as well as to investigate the effect of temperature on the system. The simulator focuses on the use of the English style of riding that uses direct force from the reins to guide a horse to turn or stop. Data was collected by hanging weights from the load …

Harmonic Detection And Selectively Focusing Electromagnetic Waves Onto Nonlinear Targets Using Time-Reversal, Joseph Michael Faia

Graduate Theses - Electrical and Computer Engineering

Ultra-wide band radar is a growing interest for the enhanced capability of ranging, imaging, and multipath propagation. An ultra-wide band pulse imposed on a system provides a near impulse like response and is, therefore, more descriptive than a conventional monotonic pulse. Combining pulse inversion with ultra-wide band DORT (a French acronym for the decomposition of the time reversal operator) is a technique which could be used to for greater visibility of nonlinear targets via harmonic detection in the presence of larger linear scatterers. Energy can be selectively focused onto nonlinear scatterers in complex, inhomogeneous environments. This thesis1, will expand upon …

Long-Range Indoor Emitter Localization From 433mhz And 2.4ghz Wlan Received Signal Strengths, Hang Du

Graduate Theses - Electrical and Computer Engineering

An improved search method for localizing a radio emitter in a building from its signal strength is proposed and implemented. It starts from floor level determination, which samples the signal strength on each floor and determines the floor level of the emitter. Then the search is conducted iteratively on a specific floor. For each round of search, one-dimensional (1-D) or two-dimensional (2-D) signal strength is collected according to the actual structure of the floor. The signal strength data are processed to fit a 1-D curve or a 2-D surface with regression models to establish an indicator or trend, which can …

Differential Launch Structures And Common Mode Filters For Planar Transmission Lines, Zachary Thomas Bergstedt

Graduate Theses - Electrical and Computer Engineering

Increases in signal speeds and decreases in dimensions pose increasing threats to signal integrity (SI) and electromagnetic compatibility (EMC) in differential interconnects due to the enhanced risk of common mode (CM) conversion. This thesis examines CM filtering solutions for multiple transmission topologies that mitigate CM noise, reducing the threat to SI and EMC. These topologies include microstrip and stripline, which are the most commonly used transmission line architecture in printed circuit boards (PCB), and broadside coupled coplanar waveguides (BC-CPW). Stripline and BC-CPW transmission lines have lower dispersion and attenuation than the commonly used microstrip but have added complexity in introducing …

An Engineer’S Rules For Running A Business, Singapore Management University

Perspectives@SMU

Peter Ho sold everything he had to make his business a success; 10 rules guide his thinking

On a lobby wall of Singapore engineering firm HOPE Technik are 10 company rules that set the organisational tone. Co-founder and CEO Peter Ho describes them as “very personal”, none perhaps more so than the first two:

1. It is a passion and a career, not a job.

2. We are engineering commandos. Small in number, strong in force.

Investigation Of Gender Bias Among Students And Faculty At A Small, Private Stem College, Olivia Katherine Ottone

Graduate Theses - Engineering Management

Current research on gender bias in STEM education indicates that non-male students are more likely to experience unfavorable gendered biases from their peers and faculty than male students. Much of this research primarily focuses on large, research institutions or data from national surveys. The intent of this research is to study gender bias, the perception of it among students, and its manifestations among students and faculty, in the context of a small, private STEM college. Additionally, this study examines possible strategies to minimize students’ experiences with gender bias. Research was conducted at Rose-Hulman Institute of Technology (RHIT) during the 2017-2018 …

Illuminator, Volume 1, Issue 8, Batten College Of Engineering & Technology, Old Dominion University

College of Engineering & Technology Newsletter

May 2018 issue of Illuminator, a monthly publication of ODU's Batten College of Engineering and Technology.

Effect Of Calcium Concentration On Calcite Flotation From Apatite Using Carbonic Gas, Amanda Soares, Suzanne Ferreira De Mello, Rafael Teixeira Rodrigues

Beneficiation of Phosphates VIII

The most widely industrial flotation process for the treatment of phosphate ores containing carbonate as gangue minerals, especially in China, Saudi Arabia, Morocco, use strong acids, such as H₃PO₄ and H₂SO₄ as apatite depressants, and the carbonate minerals (especially calcite and dolomite) are selectively floated with the use of fatty acids as collectors at pH between 5.5 - 6.0. The flotation process currently considered for apatite concentration for the Santa Quitéria ore (Brazil) was developed in the middle of the 1980´s at the Center for Development of Nuclear Technology and involves bulk flotation of …

History And Future Of Phosphate Mining And Beneficiation In South Africa, Marius Porteus

Beneficiation of Phosphates VIII

The major igneous phosphate deposit in Phalaborwa was discovered in 1904. The establishment of the Phosphate Development Corporation (Foskor) in 1951 catalyzed the development and growth of phosphate mining and phosphate fertilizer manufacturing in South Africa as well as associated businesses. This keynote address covers four major topics: 1) chemical and mineralogical properties of major phosphate deposits in South Africa, 2) mining and beneficiation practices, 3) technical challenges and evolution of processing technologies, and 4) future trends.

Designing A Distributed Network Of Air Quality Sensors, Kaylee Rauso

Computer Science and Computer Engineering Undergraduate Honors Theses

The deterioration of human and environmental health due to worsening outdoor air quality is a serious global threat. A step towards improving the current state of ambient air worldwide is the increased collection of data for government policy, research, and general public use. Currently, reliable data is only collected at a handful of sites in the state of Arkansas and sparsely across the country. The purpose of this project was to design an inexpensive air quality sensor to saturate entire cities with nodes which transmit air data to a sensor for a web application to display. The prototype node was …

A Folded Cascode Operational Amplifier With Wide-Swing Current Mirrors And High Icmr, Designed With A 1.2-Micron Silicon-Carbide Process, Austin Gattis

Electrical Engineering Undergraduate Honors Theses

This thesis describes in detail the process of designing, simulating, and creating the layout for a modified folded cascode op-amp, fabricated with silicon carbide MOSFETS. The modifications consist of using a wide-swing current mirror to help deal with output voltage issues stemming from high threshold voltages in the silicon carbide process, as well as using a modification that allows for an increased input common mode range. The folded cascode op-amp uses silicon carbide transistors, as it is intended to be used for high temperature applications, ideally in the 25 C - 300 C range. It is designed to have 25 …

Command Validation For Cybersecure Power Router, Isaac M. Kroger

Electrical Engineering Undergraduate Honors Theses

For grid-connected homes equipped with solar panels, power electronics are necessary to manage and convert power between the solar panels, battery storage, grid, and residential load. A power router can be used to manage these power electronics and govern power generation, storage, and distribution within the household. This level of control makes power routers that do not employ cybersecurity a target for external attacks. The use of command validation is an effective way to prevent unauthorized commands from maliciously altering the state of a home’s power router. The purpose of this thesis is to describe the development of the command …

Modeling Eeg And Tdcs In Scirun Software Packages, Aiden Keene, Aiden Thomas Keene

Senior Honors Projects

Never before has there been a greater emphasis on improving the shortcomings of treating mental health conditions. Our generation has more knowledge about technological practices with the potential to monitor and treat mental health symptoms than that of any generation before us. A breakthrough in this field made by CREmedical is called Tripolar Concentric Ring Electrodes (TCRE’s), which can measure signals from the brain more accurately than conventional electrodes. At CREmedical, TCREs are being used to study differences in electrical activity in the brain so as to identify abnormalities, and monitor responses to stimulation therapies. This semester I had the …

Comparison Of Data Transfer Alternatives In Asynchronous Circuits, Mark Howard

Computer Science and Computer Engineering Undergraduate Honors Theses

Digital integrated circuits (ICs) have become progressively complex in their functionality. This has sped up the demand for asynchronous architectures, which operate without any clocking scheme, considering new challenges in the timing of synchronous systems. Asynchronous ICs have less stringent environmental constraints and are capable of maintaining reliable operation in extreme environments, while also enjoying potential benefits such as low power consumption, high modularity, and improved performance. However, when the traditional bus architecture of synchronous systems is applied to asynchronous designs, handshaking protocols required for asynchronous circuit operation result in significantly increased power consumption, offsetting the low power benefit of …

Comparison Of Google Image Search And Resnet Image Classification Using Image Similarity Metrics, David Smith

Computer Science and Computer Engineering Undergraduate Honors Theses

In this paper, we compare the results of ResNet image classification with the results of Google Image search. We created a collection of 1,000 images by performing ten Google Image searches with a variety of search terms. We classified each of these images using ResNet and inspected the results. The ResNet classifier predicted the category that matched the search term of the image 77.5% of the time. In our best case, with the search term “forklift”, the classifier categorized 92 of the 100 images as forklifts. In the worst case, for the category “hammer”, the classifier matched the search term …

Automatic Testing In The United States Air Force, Pearson Wade

Computer Science and Computer Engineering Undergraduate Honors Theses

The need for standardized Automatic Testing Equipment in the United States Department of Defense has brought about new policies and procedures within entities like the United States Air Force. The diversity and lifespan of systems such as jets, missiles, drones, and other electronics have brought on the need for a new system known as the Versatile Depot Automatic Test Station, or VDATS. The VDATS handles the automatic testing of replaceable digital circuits from different systems. I was introduced to this system firsthand during my time as an intern at Tinker AFB, Oklahoma. This new standardized approach to testing a diverse …

Flexural Rigidity Evaluation Of Seismic Performance Of Hollow-Core Composite Bridge Columns, Mohanad M. Abdulazeez, Mohamed Elgawady

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This paper investigates experimentally the seismic behavior of two hollow-core fiber-reinforced polymer-concrete-steel HC-FCS columns under cyclic loading as a cantilever. The typical precast HC-FCS member consists of a concrete wall sandwiched between an outer fiber-reinforced polymer (FRP) tube and an inner steel tube. The FRP tube provides continuous confinement for the concrete wall along the height of the column. Five large-scale HC-FCS columns were investigated during this study to estimate the effective flexural (which is an important factor to define the buckling capacity and deflection of such columns) and the effective structural stiffness of the composite columns. These columns have …

Scada And Plc Systems Configuration For The Ncrept Test Facility, Arman Ahmed

Electrical Engineering Undergraduate Honors Theses

This thesis details the project to update the control and interface system of the National Center for Reliable Electric Power Transmission (NCREPT) testing facility. The need for this project arose from the 2017-2018 expansion of the facility, which included some modifications in the layout of electrical equipment used for testing purposes. These modifications necessitated the update of the control and interface system. Additionally, the old system was implemented a decade ago and is nearing obsolescence, so the facility’s expansion served as an opportune time for an upgrade.

There were two main parts to the scope of this project, which were …

Dynamic 3d Network Data Visualization, Brok Stafford

Computer Science and Computer Engineering Undergraduate Honors Theses

Monitoring network traffic has always been an arduous and tedious task because of the complexity and sheer volume of network data that is being consistently generated. In addition, network growth and new technologies are rapidly increasing these levels of complexity and volume. An effective technique in understanding and managing a large dataset, such as network traffic, is data visualization. There are several tools that attempt to turn network traffic into visual stimuli. Many of these do so in 2D space and those that are 3D lack the ability to display network patterns effectively. Existing 3D network visualization tools lack user …

The 3d Abstract Tile Assembly Model Is Intrinsically Universal, Aaron Koch, Daniel Hader, Matthew J. Patitz

Computer Science and Computer Engineering Undergraduate Honors Theses

In this paper, we prove that the three-dimensional abstract Tile Assembly Model (3DaTAM) is intrinsically universal. This means that there is a universal tile set in the 3DaTAM which can be used to simulate any 3DaTAM system. This result adds to a body of work on the intrinsic universality of models of self-assembly, and is specifically motivated by a result in FOCS 2016 showing that any intrinsically universal tile set for the 2DaTAM requires nondeterminism (i.e. undirectedness) even when simulating directed systems. To prove our result we have not only designed, but also fully implemented what we believe to be …

Reprapable Recyclebot: Open Source 3-D Printable Extruder For Converting Plastic To 3-D Printing Filament, Aubrey Woern, Joseph Mccaslin, Adam Pringle, Joshua M. Pearce

Department of Materials Science and Engineering Publications

In order to assist researchers explore the full potential of distributed recycling of post-consumer polymer waste, this article describes a recyclebot, which is a waste plastic extruder capable of making commercial quality 3-D printing filament. The device design takes advantage of both the open source hardware methodology and the paradigm developed by the open source self-replicating rapid prototyper (RepRap) 3-D printer community. Specifically, this paper describes the design, fabrication and operation of a RepRapable Recyclebot, which refers to the Recyclebot’s ability to provide the filament needed to largely replicate the parts for the Recyclebot on any type of RepRap 3-D …