Engineering Commons^™

The Odijk Regime In Slits, Douglas R. Tree, Wesley F. Reinhart, Kevin D. Dorfman

Faculty Publications

De Gennes’ blob theory has been remarkably successful at describing weakly confined polymers in both slits and channels, and comparable results surround Odijk’s theory of deflection segments for strongly confined wormlike polymers in nanochannels. However, given the success of Odijk’s theory in channels, it is remarkable that there is no comprehensive theory for the simple case of a wormlike polymer strongly confined between two parallel plates. We propose such a theory by drawing inspiration from the existing literature on ideal wormlike chains in slits and Daoud and de Gennes’ idea of mapping a slit-confined chain to a two-dimensional chain. We …

Microstructure Design And Experimental Characterization Of Functional Elastic Metamaterials, Rui Zhu

Theses and Dissertations

Elastic metamaterials are of growing interest due to their dramatically increased manipulation ability as well as their novel engineering applications. The purpose of this research is to develop and model elastic metamaterials with unusual effective properties and their applications in low frequency elastic wave attenuation and vibration suppression. The working principle of the elastic metamaterials is to use man-made microstructures, local resonators, on a scale much less than its working wavelength. Therefore it is possible to describe their response by using dispersive homogenized effective media. First, we developed a retrieval method to obtain effective material properties of the metamaterial and …

College Of Engineering News, Georgia Southern University

College of Engineering & Computing: News & Publications (2010-2023)

• Eagle Motorsports Impresses in 2014 Baja SAE

Durability Studies On Native Soil-Based Controlled Low Strength Materials, Bhaskar Chittoori

Civil Engineering Faculty Publications and Presentations

The Integrated Pipeline Project (IPL) is a collaborative effort between the Tarrant Regional Water District (TRWD) and Dallas Water Utilities (DWU), which bring additional water supplies to the Dallas / Fort Worth area. As part of a sustainability initiative, several studies were conducted to assess the reuse potential of excavated materials along the IPL project. One of these studies involved using the excavated material as an ingredient in Controlled Low Strength Material, often known as CLSM or flowable fill. This flowable fill can be used as bedding and haunch material in pipeline construction. These CLSMs meet the specifications in the …

Depolarization Mechanisms Of Pbzr0.52ti0.48o3 And Pbzr0.95ti0.05o3 Poled Ferroelectrics Under High Strain Rate Loading, Sergey I. Shkuratov, Jason Baird, Vladimir G. Antipov, Evgueni F. Talantsev, Hwan R. Jo

Mining Engineering Faculty Research & Creative Works

Stress-induced and thermal-induced depolarization studies along with X-ray diffraction were performed on lead zirconate titanate ferroelectrics of different compositions, PbZr_0.52Ti_0.48O₃ (PZT 52/48) and PbZr_0.95Ti_0.05O₃ (PZT 95/5). Specimens were shocked loaded perpendicular to the polarization vector. It was found that the polarity of the stress-induced charge released by PZT 52/48 and 95/5 was opposite to the polarity of the charge generated due to the piezoelectric effect. PZT 52/48 was only partially (45%) depolarized under 1.5±0.1 GPa mechanical compression, as opposed to PZT 95/5 which was fully depolarized. The experimental results indicate …

Making Every Gram Count - Big Measurements From Tiny Platforms, C. S. Fish, C. M. Swenson, S. Bailey, R. Bevilacqua, T. Neilsen, A. Marchant, C. Frazier, E. Stromberg, C. Weston, M. Jeppesen, J. Sojka

Space Dynamics Laboratory Publications

Significant advances in Earth, solar, and space physics over the next decades will originate from new, system-level observational techniques. The most promising technique to still be fully developed and exploited requires conducting multi-point or distributed constellation-based observations. This system-level observational approach is required to understand the “big picture” coupling between disparate regions such as the solar-wind, magnetosphere, ionosphere, upper atmosphere, land, and ocean. However, the costs to date of these and other similar proposed constellations have been prohibitive given the traditional “large satellite” architectures and the multiple launch vehicles required for implementing the constellations.

Financially sustainable development and deployment of …

Low Noise, High Detectivity Photodetectors Based On Organic Materials, Fawen Guo

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Organic photodetectors (OPDs) are potentially useful in many applications because of their light weight, flexibility and good form factors. Despite the high detectivities that have been frequently reported for OPDs recently, the application of these OPDs for weak light detection has been rarely demonstrated.

In this thesis, low noise, high gain photodetectors based on organic and ZnO nanoparticles were proposed and demonstrated for highly sensitive UV light detection. The nanocomposite photodetector works in a hybrid mode of photodiode and photoconductor with the transition controlled by the UV light illumination. The nanocomposite detector shows two orders of magnitude higher sensitivity than …

Midrange Magnetically-Coupled Resonant Circuit Wireless Power Transfer, Varun Nagoorkar

Electrical Engineering Theses

Recent years have seen numerous efforts to make wireless power transfer (WPT) feasible for application in diverse fields, from low-power domestic applications and medical applications to high-power industrial applications and electrical vehicles (EVs). As a result, it has been found that WPT by means of non-radiative magnetically-coupled resonant circuits is an optimum method for mid-range applications where the separation of source and receiver is in the range of 1-2m.This thesis investigates various aspects of the design of magnetically-coupled resonant circuits for non-radiative WPT. Firstly, a basic four-coil network for a mid-range (1-2m gap) WPT system with a single power source …

Reduction Of Transportation Greenhouse Gas Emissions To Mitigate Climate Change Impacts, Mary Snow, Richard Snow

Publications

Weather affects almost all modes of transportation in a modern society, and likewise, transportation has an enormous impact on the weather. Transportation greenhouse gas emissions (GHG) impact climate change, which impacts transportation in return. Reduction of transportation impacts on climate change can mitigate the reverse climate change impacts on transportation. This paper examines the relationship between transportation and climate change and establishes prospective solutions to reduce transportation greenhouse gas emission impacts on climate change and mitigate the reverse climate change impacts on transportation.

The Santa Clara, 2014-05-22, Santa Clara University

The Santa Clara

No abstract provided.

Extraction Of Intrinsic Fluorescence From Single Fiber Fluorescence Measurements On A Turbid Medium: Experimental Validation, U. A. Gamm, C. L. Hoy, F. Van Leeuwen - Van Zaane, H. J. C. M. Sterenborg, S. C. Kanick, D J. Robinson, A. Amelink

Dartmouth Scholarship

Abstract

The detailed mechanisms associated with the influence of scattering and absorption properties on the fluorescence intensity sampled by a single optical fiber have recently been elucidated based on Monte Carlo simulated data. Here we develop an experimental single fiber fluorescence (SFF) spectroscopy setup and validate the Monte Carlo data and semi-empirical model equation that describes the SFF signal as a function of scattering. We present a calibration procedure that corrects the SFF signal for all system-related, wavelength dependent transmission efficiencies to yield an absolute value of intrinsic fluorescence. The validity of the Monte Carlo data and semi-empirical model is …

Using Near-Field Coupled Circularly Polarized Antennas As Frequency Independent Variable Phase-Shifters, Vit Sipal, Adam Narbudowicz, Max Ammann

Articles

This paper introduces a novel concept of frequency-independent variable phase-shifters. It is based on the use of circularly polarized (CP) antennas coupled in the near-field. For transmission between two CP antennas in the far-field, a rotation around the boresight axis produces a phase change in the transfer function. This concept is exploited and validated also for near-field coupling between two CP antennas. Therefore, two close-coupled CP antennas can act as a adjustable phase-shifter with the phase-shift controlled by the angle between the structures. The bandwidth depends on the CP bandwidth of the antenna. This concept is valuable for future phase-shifters …

Energy-Efficient Stdp-Based Learning Circuits With Memristor Synapses, Xinyu Wu, Vishal Saxena, Kristy A. Campbell

Electrical and Computer Engineering Faculty Publications and Presentations

It is now accepted that the traditional von Neumann architecture, with processor and memory separation, is ill suited to process parallel data streams which a mammalian brain can efficiently handle. Moreover, researchers now envision computing architectures which enable cognitive processing of massive amounts of data by identifying spatio-temporal relationships in real-time and solving complex pattern recognition problems. Memristor cross-point arrays, integrated with standard CMOS technology, are expected to result in massively parallel and low-power Neuromorphic computing architectures. Recently, significant progress has been made in spiking neural networks (SNN) which emulate data processing in the cortical brain. These architectures comprise of …

Fluid Flow-Induced Mesenchymal Stem Cell Migration: Role Of Fak And Rock Mechanosensors, Brandon D. Riehl

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

The study of mesenchymal stem cell (MSC) migration under mechanical stimulation conditions with investigation of the underlying molecular mechanism could lead to a better understanding and outcomes in stem cell-based regenerative medicine. MSCs having multipotent regenerative capability exist in niches in the bone marrow, muscle, vasculature, and in other tissues throughout the body, and their migration through tissues and vasculature for the repair of damaged tissue is a key process of cell and tissue homeostasis, remodeling, and regeneration. While cell migration in response to cytokines and other chemo-attractants is relatively well understood, little is revealed in regard to the effect …

Mobile Game Application: The Magictale, Lu Cao, Albert Chang, Yetian Mao

Computer Science and Engineering Senior Theses

Many smartphone games today consist of players making simple and repetitive actions with their fingers to play the game. Compared to traditional PC Role Playing games (RPG), current mobile games do not provide the same fictional aspects and complex components. Players creativity is almost non-existent in most simple mobile application games. To address this issue, we propose to create a IOS mobile application game which combines the complex components of traditional PC RPGs and touch screen actions of mobile games.

Comprehensive T Cell Antigen Discovery Using A Genomic Approach, Jessica Baker

Vaccine Technology IV

No abstract provided.

Resilient Families Project Web Application, Stephanie Servi, Patrick Neill

Computer Science and Engineering Senior Theses

In order to help The Resilient Families Project, a stress management course for at-risk families, we have created an online application to allow users to take stress examinations more frequently, and to record their thoughts and interactions pertaining to the project. In this paper, we document our thought process, design rationale and any other relevant information to the web application for the Resilient Families Project.

Processing Of Monolayer Materals Vlanterfacial Reactions, Peter Werner Sutter, Eli Anguelova Sutter

Department of Electrical and Computer Engineering: Faculty Publications

A method of forming and processing of graphene is disclosed based on exposure and selective intercalation of the partially graphene-covered metal Substrate with atomic or molecular intercalation species such as oxygen (O) and nitrogen oxide (NO). The process of intercalation lifts the strong metal carbon coupling and restores the characteristic Dirac behav ior of isolated monolayer graphene. The interface of graphene with metals or metal-decorated substrates also provides for controlled chemical reactions based on novel functionality of the confined space between a metal Surface and a graphene sheet.

State Of The Art Of Using Virtual Reality Technologies In Built Environment Education., Garrett Keenaghan, Imre Horváth

Conference papers

the application of virtual reality technologies in built environment education (BEE). In addition to an analysis of the current trends and developments in current virtual reality technologies and systems, it also evaluates their educational usability and effectiveness in the mirror of the literature. First, a reasoning model is introduced, which is used as a structuring skeleton of the paper. The context of the analysis is learning experience of BEE students who tend to form individual perspective and expectations. When the experience and perspective of the virtual reality developer differs from that of the user the virtual environment-based learning may result …

Ultraviolet Laser Crystallized Zno:Al Films On Sapphire With High Hall Mobility For Simultaneous Enhancement Of Conductivity And Transparency, Qiong Nian, Martin Y. Zhang, Bradley D. Schwartz, Gary J. Cheng

Birck and NCN Publications

One of the most challenging issues in transparent conductive oxides (TCOs) is to improve their conductivity without compromising transparency. High conductivity in TCO films often comes from a high carrier concentration, which is detrimental to transparency due to free carrier absorption. Here we show that UV laser crystallization (UVLC) of aluminum-doped ZnO (AZO) films prepared by pulsed laser deposition on sapphire results in much higher Hall mobility, allowing relaxation of the constraints of the conductivity/transparency trade-off. X-ray diffraction patterns and morphological characterizations show grain growth and crystallinity enhancement during UVLC, resulting in less film internal imperfections. Optoelectronic measurements show that …

Time-Dependent Density Functional Theory Of Coupled Electronic Lattice Motion In Quasi-Two-Dimensional Crystals, Vladimir U. Nazarov, Fhhad Alharbi, Timothy Fisher, Sabre Kais

Birck and NCN Publications

Electron-holes, phonons, and plasmons come in close proximity to each other in the low-energy range of the excitation spectrum of two-dimensional (2D) crystals, breaking the validity of the weakly interacting-quasiparticles picture. By including the lattice oscillations into the scheme of time-dependent density-functional theory, we open a pathway to the ab initio treatment of the coupled low-energy excitations in 2D crystals. With the use of graphene as an important test system, we find the strong coupling of the elementary excitations, giving rise to new hybrid collective modes. The total (including both the electronic and ionic response) dielectric function epsilon(tot)(omega) is constructed …

Quantifying The Impacts Of Initial Condition And Model Uncertainty On Hydrological Forecasts, Caleb Matthew Dechant

Dissertations and Theses

Forecasts of hydrological information are vital for many of society's functions. Availability of water is a requirement for any civilization, and this necessitates quantitative estimates of water for effective resource management. The research in this dissertation will focus on the forecasting of hydrological quantities, with emphasis on times of anomalously low water availability, commonly referred to as droughts. Of particular focus is the quantification of uncertainty in hydrological forecasts, and the factors that affect that uncertainty. With this focus, Bayesian methods, including ensemble data assimilation and multi-model combinations, are utilized to develop a probabilistic forecasting system. This system is applied …

Seasonal Variability And Long-Term Evolution Of Tropospheric Composition In The Tropics And Southern Hemisphere, K. M. Wai, S. Wu, A. Kumar, H. Liao

Michigan Tech Publications, Part 1

Impacts on tropospheric composition in the tropics and the Southern Hemisphere from biomass burning and other emission sources are studied using a global chemical transport model, surface measurements and satellite retrievals. Seasonal variations in observed CO at remote island sites are examined. Easter Island (eastern Pacific Ocean) is impacted indirectly by the hemispheric zonal transport of CO due to the burning in southern Africa/South America, via the westerlies. An increasing trend in CO by 0.33 ppb yr-1 in the past decade at Ascension Island is attributed to the combined effects of South American/southern Africa burnings and the increases in CH4 …

Energy Mgmt Asset Value.Pdf, Khalid Siddiqi

Faculty Articles

The objective of this study was to establish a relationship between facility energy management and asset valuation in federal facilities. Current operating pool of federal government facilities of varying size and location were considered in this study to determine this relationship. The overall value of a building asset was considered and evaluated in the context of the building’s energy performance over time. One major conclusion was that facilities which had better energy management have higher “tier” ratings than those buildings which had little to no energy management. The findings of this study would be useful for facility/building managers and asset …

A Systematic Security Evaluation Of Android’S Multi-User Framework, Edward Paul Ratazzi, Yousra Aafer, Amit Ahlawat, Hao Hao, Yifei Wang, Wenliang Du

Electrical Engineering and Computer Science - All Scholarship

Like many desktop operating systems in the 1990s, Android is now in the process of including support for multiuser scenarios. Because these scenarios introduce new threats to the system, we should have an understanding of how well the system design addresses them. Since the security implications of multi-user support are truly pervasive, we developed a systematic approach to studying the system and identifying problems. Unlike other approaches that focus on specific attacks or threat models, ours systematically identifies critical places where access controls are not present or do not properly identify the subject and object of a decision. Finding these …

Effect Of 406 Mhz Elts And Cospas-Sarsat Cessation Of 121.5 Mhz Elt Monitoring On Search And Rescue Duration For General Aviation Aircraft Accidents In The Contiguous United States, Ryan J. Wallace, Todd P. Hubbard

International Journal of Aviation, Aeronautics, and Aerospace

Emergency Locator Transmitters (ELTs) are credited with saving hundreds of lives every year in the United States. Following an aircraft accident, these devices transmit an emergency beacon signal to the COSPAS-SARSAT satellite network, directing search and rescue forces to the crash site. In recent years, this constellation has been plagued by ELT false alarms, propagating a technology transition to new 406 MHz ELT systems. In 2009, the group ceased monitoring of 121.5 MHz ELTs, degrading search and rescue capability for legacy ELTs. The Federal Communications Commission twice attempted to enact regulations to mandate industry-wide transition to 406 MHz ELTs, however, …

Effects Of Temperature And Humidity On The Barrier Properties Of Biaxially-Oriented Polypropylene And Polyvinyl Alcohol Films, Chen Mo, Wang Yuan, Wang Lei, Yin Shijiu

Journal of Applied Packaging Research

The goal of this work was to study the effects of relative humidity (RH) and temperature on the barrier properties of biaxially-oriented polyvinyl alcohol (BOVLON) and polypropylene (BOPP) films. The water vapor transmission rate (WVTR) and the oxygen transmission rate (OTR) of the BOVLON and BOPP films were determined with MOCON PERMATRAN-W and MOCON OX-TRAN at 10℃-40℃ and 35%-90% RH. The results indicated that RH and temperature had different influence on the WVTR and OTR of the BOVLON and PP films. The OTR and WVTR values of the BOVLON films increase both exponentially with RH. Their WVTR values increase exponentially …

Scada Test Bed - Water Tank System, Allison Linn

Mahurin Honors College Capstone Experience/Thesis Projects

A SCADA, or Supervisory Control And Data Acquisition, system is a computer-controlled system that monitors and controls industrial processes remotely. Electric grids, water supplies, and pipelines are all significant SCADA systems. These systems can be controlled and monitored remotely and are typically composed of multiple programmable logic controllers (PLCs). However, SCADA systems are inherently vulnerable to cyber attacks.

During the previous academic year, an electrical engineering senior project team was assigned the task of designing and constructing a SCADA test bed for WKU’s Engineering-Manufacturing-Commercialization Center (EMCC). The test bed was to have three systems simulating SCADA systems: a traffic light …

Design And Prototyping Of An Antenna-Coupled Cryotron, Shauna Jensen

Dissertations and Theses

Grid-scale integration of renewable energy sources and smart grid devices has created new demands in flexible power conversion. State-of-the-art semiconductor power switches present limitations in power handling capability, as well as forward and reverse breakdown voltages. Superconducting materials are a viable alternative due to their robustness against high ampacities, large electric fields and abrupt changes in power flow. This work pays focus to material testing and apparatus design for an antenna-coupled cryotron (ACC), which is a superconducting power switch.
Design, fabrication and testing are examined for a longitudinal resonant cavity, paired with monopole transmit and modified slot receive antennae. These …

Adding Vision To A Quadrotor: A Design-Build-Test Adventure, Darren Tinker

Mahurin Honors College Capstone Experience/Thesis Projects

Quadrotors are small and exceptionally agile vehicles with maneuverability that permits both indoor and outdoor flight. The vast majority of quadrotors are flown autonomously as drones or remotely by a human-operator. Applications of quadrotors range from commercial deliveries, to military and law reconnaissance as well as research tools for various fields. Our lab at Western Kentucky University built a quadrotor in 2013, and we have been exploring various modifications to refine its performance and various applications in which it could be productively employed. Recently, research has focused on the addition of a camera to add capabilities for first person view …