Engineering Commons^™

A Highly Sensitive, Polarization Maintaining Photonic Crystal Fiber Sensor Operating In The Thz Regime, Sohel Rana, Nirmala Kandadai, Harish Subbaraman

Electrical and Computer Engineering Faculty Publications and Presentations

In this paper, a high sensitivity, polarization preserving photonic crystal fiber (PCF), based on circular air holes for sensing in the terahertz (THz) band, is presented. The finite element method, a practical and precise computational technique for describing the interactions between light and matter, is used to compute the modal properties of the designed fiber. For the designed PCF, comprising of circular air holes in both the cladding and in the porous core, a relative sensitivity of 73.5% and a high birefringence of 0.013 are achieved at 1.6 THz. The all circular air-hole structure, owing to its simplicity and compatibility …

Tying Together Multiscale Calculations For Charge Transport In P3ht: Structural Descriptors, Morphology, And Tie-Chains, Evan D. Miller, Matthew L. Jones, Eric Jankowski

Materials Science and Engineering Faculty Publications and Presentations

Evaluating new, promising organic molecules to make next-generation organic optoelectronic devices necessitates the evaluation of charge carrier transport performance through the semi-conducting medium. In this work, we utilize quantum chemical calculations (QCC) and kinetic Monte Carlo (KMC) simulations to predict the zero-field hole mobilities of ~100 morphologies of the benchmark polymer poly(3-hexylthiophene), with varying simulation volume, structural order, and chain-length polydispersity. Morphologies with monodisperse chains were generated previously using an optimized molecular dynamics force-field and represent a spectrum of nanostructured order. We discover that a combined consideration of backbone clustering and system-wide disorder arising from side-chain conformations are correlated with …

Preformed-Particle-Gel Placement And Plugging Performance In Fractures With Tips, Ze Wang, Baojun Bai

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Preformed-particle gels (PPGs) have been applied for reducing excessive water production caused by fractures in reservoirs. A portion of the fractures existing in reservoirs is composed of a void part and a fracture tip. The PPG placement behavior and plugging performance could be mainly affected by the fracture tips. A fracture with a tip, called a "partially open fracture" in this paper, was designed to investigate the placement and water-plugging performance of PPG. Cylindrical sandstone cores were used to manufacture partially open fractures. Pressure data of PPG injection, post-gel water breakthrough, and stable injection were analyzed to investigate the PPG …

Methane Oxidation Potential Of Uncomposted Yard Waste As A Landfill Biocover, Gomathy Radhakrishna Iyer

Civil Engineering Dissertations - Archive

Biocovers are widely used in landfills to oxidize emissions of the greenhouse gas methane. Biocovers used till date are fully or partially made of composts. Compost takes time and effort to create, and costs about $10 per cubic yard on an average. Even more importantly, however, production of compost, although theoretically an aerobic process, actually generates methane, from 3.2 to 362 kg CO2-equivalents per ton of wet waste composted, depending on the type of waste, whether open or enclosed composting technology is used, and other factors. To reduce the net greenhouse gas emissions from biocovers, this research explores the potential …

Hpfrc And Rc Slab-Beam-Column Connections Under Extreme Earthquake Loading And Further Improvement Of Novel Double-Beam-Coupling Beams, Youngjae Choi

Civil Engineering Dissertations - Archive

The work presented in this dissertation is divided into two parts. Each part has drawn its own results. Reinforced concrete (RC) buildings resist a strong earthquake through structural foundations, diaphragms, and vertical elements. Moment-resisting frames and shear walls are primary-used vertical elements in RC buildings. The moment-resisting frames consist of columns, beams that frame into the column and beam column joints where the columns and beams meet. A key point of designing the moment-resisting frames against a strong earthquake is to ensure beam-column connections to dissipate as much energy possible. The shear wall often becomes two separate slender cantilever walls …

Novel Infrastructure Monitoring Using Multifaceted Unmanned Aerial Vehicle Systems - Close Range Photogrammetry (Uav - Crp) Data Analysis, Surya Sarat Chandra Congress

Civil Engineering Dissertations - Archive

Remote sensing is a method of collecting data without making any physical contact with the object under inspection. Modern day remote sensing kicked off with the invention of the camera and continued on to the invention of advanced satellite mounted sensors. Photogrammetry is defined as a science that measures distances using one or more images captured remotely. Remote collection of images within a range of 1000 ft is termed close-range photogrammetry (CRP). Unmanned aerial vehicle systems (UAV or UAS) have become a popular means of remotely gathering information and assessing infrastructure conditions due to their versatile nature. Multirotor and fixed-wing …

Utilization Of Geocell-Reinforced Rap Material Base Layer In Flexible Pavements: Experimental And Numerical Studies, Anu Muthumala George

Civil Engineering Dissertations - Archive

Reclaimed asphalt pavement (RAP) materials have been considered as one of the most sustainable and cost-effective options in the pavement industry. The use of RAP materials in pavement construction reduces natural resources depletion and the volume of construction debris discarded into the landfills. However, the low shear strength and high permanent deformation (PD) of RAP materials often limit their application in road bases. Utilization of mechanical stabilizers, such as geocell, for stabilizing RAP bases, have found to be effective in improving the pavement performance. The main objective of this study is to assess the efficacy of high-density polyethylene (HDPE) geocell …

Development Of The Urban Passenger Transportation Life Cycle Inventory For Comparison Across Modes Model (Transportlifecamm), Alma Angelica Hernandez Ruiz

Civil Engineering Dissertations - Archive

Against the backdrop of the increasingly complex urban passenger transportation challenges associated with megacities during the 21st century, and the effort to find the most sustainable modes of transportation for them, the spreadsheet-based model TransportLifeCAMM was developed. This model allows users in the US and Mexico to compare life cycle environmental impacts from automobile, bus, and/or subway. While other models to estimate environmental burdens from transportation exist, few of them consider emissions or energy consumption over the entire life cycle of the vehicle and the fuel (including vehicle manufacture, fuel production, maintenance, and end-of-life disposal). Furthermore, even fewer of the …

Post-Disaster Construction Labor Cost Fluctuations: Measurement And Modeling, Navid Ahmadi Esfahani

Civil Engineering Dissertations - Archive

The United States has been one of the top five countries most frequently hit by natural disasters. The post-disaster survival of cities and communities depend on their capabilities to reconstruct and repair damages to buildings and other infrastructure systems. The significant increase in the repair costs following large-scale natural disasters, also called “demand surge,” slows down the repair process that impacts many lives touched by large-scale natural disasters. Previous studies showed that post-disaster construction labor cost escalation drives the total post-disaster construction cost escalation in the U.S. The ultimate goal of this research is to (1) measure post-disaster construction labor …

Optimization Of Analytical Inverse Heat Transfer Recovery Solution, Nathan Schick

Masters Theses

This thesis describes the different methods used when trying to solve inverse heat transfer problems, particularly those involving recovering heat flux. There are currently several techniques to measure the temperature history in an object subjected to heat transfer using various temperature sensors, however these types of sensors are gradually being replaced by Temperature Sensitive Paints (TSP), a technique that is more accurate and provides a better spatial resolution. TSP is a polymer that is applied on a base object. Changes in temperature in the polymer result in variations of the luminescence intensity in the paint. These variations can be captured …

Investigation Of Kentucky For-Hire Requirements, Andrew Martin, Valerie J. Keathley, Jennifer R. Walton

Kentucky Transportation Center Research Report

This study analyzes the costs and benefits of the Kentucky For-Hire operating authority, which is issued to all carriers who pick up and drop off freight in Kentucky on a for-hire basis. It reviews current statutory and regulatory requirements, calculates the costs and benefits of administering Kentucky For-Hire, reviews the legal history of trucking regulation and deregulation, reports on a survey of other states about their practices with intrastate operating authority, and proposes three alternatives to current policies. The primary benefit of Kentucky For-Hire is that it enables the Kentucky Transportation Cabinet to verify carriers have commercial liability insurance. Several …

Aliased Tidal Variability In Mesoscale Sea Level Anomaly Maps, Edward Zaron, Richard D. Ray

Civil and Environmental Engineering Faculty Publications and Presentations

Sea level anomaly (SLA) maps are routinely produced by objective analysis of data from the constellation of satellite altimeter missions in operation since 1992. Beginning in 2014, changes in the Data Unification and Altimeter Combination System (DUACS) used to create the SLA maps resulted in improved spatial resolution of mesoscale variability, but it also increased the levels of aliased tidal variability compared to the methodology employed prior to 2014. The present work investigates the magnitude and spatial distribution of these tidal signals, which are typically smaller than 1 cmin the open ocean but can reach tens of centimeters in the …

Comparative Analysis Of Mosquito Trap Counts In The Peruvian Amazon: Effect Of Trap Type And Other Covariates On Counts And Diversity, George W. Peck, Fanny Castro-Llanos, Victor Lopez-Sifuentes, Erica Lindroth

Civil and Environmental Engineering Faculty Publications and Presentations

Efficient detection of multiple species of adult mosquitoes in various habitats using effective traps is a crucial 1st step in any disease prevention program. Novel trap types that target tropical vectors of human diseases require field testing in the habitat of the vector–disease system in question. This paper analyzes a series of mosquito trapping studies conducted at Mapacocha, San Juan Bautista District, Loreto, Peru, during August–September 2013 and April–May 2014. Six trap configurations were evaluated in forest and rural locations. Adult mosquito counts were analyzed using full Bayesian inference of multilevel generalized linear models and posterior probability point estimates of …

Data Center Holistic Demand Response Algorithm To Smooth Microgrid Tie-Line Power Fluctuation, Ting Yang, Yingjie Zhao, Haibo Pen, Zhaoxia Wang

Research Collection School Of Computing and Information Systems

With the rapid development of cloud computing, artificial intelligence technologies and big data applications, data centers have become widely deployed. High density IT equipment in data centers consumes a lot of electrical power, and makes data center a hungry monster of energy consumption. To solve this problem, renewable energy is increasingly integrated into data center power provisioning systems. Compared to the traditional power supply methods, renewable energy has its unique characteristics, such as intermittency and randomness. When renewable energy supplies power to the data center industrial park, this kind of power supply not only has negative effects on the normal …

Deep Unsupervised Pixelization, Chu Han, Qiang Wen, Shengfeng He, Qianshu Zhu, Yinjie Tan, Guoqiang Han, Tien-Tsin Wong

Research Collection School Of Computing and Information Systems

In this paper, we present a novel unsupervised learning method for pixelization. Due to the difficulty in creating pixel art, preparing the paired training data for supervised learning is impractical. Instead, we propose an unsupervised learning framework to circumvent such difficulty. We leverage the dual nature of the pixelization and depixelization, and model these two tasks in the same network in a bi-directional manner with the input itself as training supervision. These two tasks are modeled as a cascaded network which consists of three stages for different purposes. GridNet transfers the input image into multi-scale grid-structured images with different aliasing …

Automatically `Verifying’ Discrete-Time Complex Systems Through Learning, Abstraction And Refinement, Jingyi Wang, Jun Sun, Shengchao Qin, Cyrille Jegourel

Research Collection School Of Computing and Information Systems

Precisely modeling complex systems like cyber-physical systems is challenging, which often render model-based system verification techniques like model checking infeasible. To overcome this challenge, we propose a method called LAR to automatically ‘verify’ such complex systems through a combination of learning, abstraction and refinement from a set of system log traces. We assume that log traces and sampling frequency are adequate to capture ‘enough’ behaviour of the system. Given a safety property and the concrete system log traces as input, LAR automatically learns and refines system models, and produces two kinds of outputs. One is a counterexample with a bounded …

Co-Location Resistant Virtual Machine Placement In Cloud Data Centers, Amit Agarwal, Nguyen Binh Duong Ta

Research Collection School Of Computing and Information Systems

Due to increasing number of avenues for conducting cross-virtual machine (VM) side-channel attacks, the security of public IaaS cloud data centers is a growing concern. These attacks allow an adversary to steal private information from a target user whose VM instance is co-located with that of the adversary. To reduce the probability of malicious co-location, we propose a novel VM placement algorithm called “Previously Co-Located Users First”. We perform a theoretical and empirical analysis of our proposed algorithm to evaluate its resource efficiency and security. Our results, obtained using real-world cloud traces containing millions of VM requests and thousands of …

Additively-Manufactured Hybrid Rocket Consumable Structure For Cubesat Propulsion, Britany L. Chamberlain

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Three-dimensional, additive printing has emerged as an exciting new technology for the design and manufacture of small spacecraft systems. Using 3-D printed thermoplastic materials, hybrid rocket fuel grains can be printed with nearly any cross-sectional shape, and embedded cavities are easily achieved. Applying this technology to print fuel materials directly into a CubeSat frame results in an efficient, cost-effective alternative to existing CubeSat propulsion systems. Different 3-D printed materials and geometries were evaluated for their performance as propellants and as structural elements. Prototype "thrust columns" with embedded fuel ports were printed from a combination of acrylonitrile utadiene styrene (ABS) and …

Production And Biocompatibility Of Spider Silk Proteins In Goat Milk, Richard E. Decker Jr

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Due to its strength, flexibility, and biocompatibility, spider silk is a highly appealing material for applications in the medical field. Unfortunately, natural spider silk is difficult to obtain in large quantities because spiders are territorial and cannibalistic, making them impractical to farm. Synthetic spider silk proteins produced by transgenic hosts such as bacteria and goats have made it possible to obtain the quantities of spider silk needed to study it more fully and to investigate its potential uses. The spider silk proteins produced in our laboratory do not have an optimal purification method to remove all of the non-biocompatible contaminants …

Production And Purification Of Synthetic Minor Ampullate Silk Proteins, Danielle A. Gaztambide

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Spider silks are incredible natural materials that have a wide variety of properties that can rival or outperform even common synthetic materials like Nylon and Kevlar. As nature’s architects, orb-weaving spiders spin seven different silks that are used for very specific roles throughout the spider’s lifecycle. These silks are comprised of proteins called spidroins. Each of these spidroins has evolved to have properties such as strength and/or stretch that make these silks successful and highly adapted in their designated roles in web construction, prey capture and reproduction.

This study involves the production of minor ampullate silk by genetically modifying the …

A Wideband 2-D Fast Multipole Algorithm With A Novel Diagonalization Form, Ling Ling Meng, Mert Hidayetoǧlu, Tian Xia, Wei E.I. Sha, Li (Lijun) Jun Jiang, Weng Cho Chew

Electrical and Computer Engineering Faculty Research & Creative Works

It is well known that Green's function can be expressed by multipole expansion, plane-wave expansion, and exponential expansion (spectral representation). These three expansions constitute of the foundations of the fast multipole algorithm (FMA). The plane-wave expansion has the low-frequency breakdown issue due to its failure in capturing the evanescent spectra, while the multipole expansion is inefficient at high frequencies. The spectral representation usually involves in direction-dependent issue. In this communication, the 2-D FMA is interpreted as Parseval's theorem in Fourier transform. To achieve a stable and accurate transition between the multipole expansion and the plane-wave expansion, a novel diagonalization in …

On-Demand Band-Rejected Wideband Antenna Based On Peelable Resonator Membrane, Rong Wang, Min Li, Salahuddin Raju, Robert C. Roberts, Mansun Chan, Lijun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

In this letter, we present a wideband planar antenna with on-demand band-rejected characteristics based on the peelable double electric-LC (DELC) resonator membranes. By applying microfabrication techniques, the subwavelength DELC structure is completely encapsulated in a transparent and flexible thin film with a total thickness of 10 mum. Resonators with four different widths (4.0, 3.6, 3.2, 2.8 mm) are packaged as a solution kit, providing the rejection bands of 4.24-5.11, 4.61-5.38, 4.85-5.48, and 5.20-5.70 GHz, respectively. Owing to the passive and detachable features of this functional sticker, no biasing network is needed for the rejection band's on/off transition and the membrane …

Data-Enabled Computational Multiscale Method In Materials Science And Engineering, Shaoping Xiao, Amaury Lendasse, Renjie Hu

Engineering Management and Systems Engineering Faculty Research & Creative Works

In the Community of Computational Materials Science, One of the Challenges in Hierarchical Multiscale Modeling is Information-Passing from One Scale to Another, especially from the Molecular Model to the Continuum Model. a Machine-Learning-Enhanced Approach, Proposed in This Paper, Provides an Alternative Solution. in the Developed Hierarchical Multiscale Method, Molecular Dynamics Simulations in the Molecular Model Are Conducted First to Generate Datasets, Which Represents Physical Phenomena at the Nanoscale. the Datasets Are Then Used to Train Neural Networks for Failure Classification and Stress Regressions. Finally, the Well-Trained Learning Machines Are Implemented in the Continuum Model to Study the Mechanical Behaviors of …

Blood-Based Biomarkers For Predicting The Risk For Five-Year Incident Coronary Heart Disease In The Framingham Heart Study Via Machine Learning, Meeshanthini V. Dogan, Steven R.H. Beach, Ronald L. Simons, Amaury Lendasse, Brandan Penaluna, Robert A. Philibert

Engineering Management and Systems Engineering Faculty Research & Creative Works

An Improved Approach for Predicting the Risk for Incident Coronary Heart Disease (CHD) Could Lead to Substantial Improvements in Cardiovascular Health. Previously, We Have Shown that Genetic and Epigenetic Loci Could Predict CHD Status More Sensitively Than Conventional Risk Factors. Herein, We Examine Whether Similar Machine Learning Approaches Could Be Used to Develop a Similar Panel for Predicting Incident CHD. Training and Test Sets Consisted of 1180 and 524 Individuals, respectively. Data Mining Techniques Were Employed to Mine for Predictive Biosignatures in the Training Set. an Ensemble of Random Forest Models Consisting of Four Genetic and Four Epigenetic Loci Was …

Spin-Controlled Wavefront Shaping With Plasmonic Chiral Geometric Metasurfaces, Yang Chen, Xiaodong Yang, Jie Gao

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Metasurfaces, as a two-dimensional (2D) version of metamaterials, have drawn considerable attention for their revolutionary capability in manipulating the amplitude, phase, and polarization of light. As one of the most important types of metasurfaces, geometric metasurfaces provide a versatile platform for controlling optical phase distributions due to the geometric nature of the generated phase profile. However, it remains a great challenge to design geometric metasurfaces for realizing spin-switchable functionalities because the generated phase profile with the converted spin is reversed once the handedness of the incident beam is switched. Here, we propose and experimentally demonstrate chiral geometric metasurfaces based on …

Accelerated Freezing Due To Droplet Pinning On A Nanopillared Surface, Rachel Bohm, Mohammad Rejaul Haque, Chuang Qu, Edward C. Kinzel, Amy Rachel Betz

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The freezing process is significantly influenced by environmental factors and surface morphologies. At atmospheric pressure, a surface below the dew and freezing point temperature for a given relative humidity nucleates water droplets heterogeneously on the surface and then freezes. This paper examines the effect of nanostructured surfaces on the nucleation, growth, and subsequent freezing processes. Microsphere Photolithography (MPL) is used to pattern arrays of silica nanopillars. This technique uses a self-assembled lattice of microspheres to focus UV radiation to an array of photonic jets in photoresist. Silica is deposited using e-beam evaporation and lift-off. The samples were placed on a …

Synergic Titanium Nitride Coating And Titanium Doping By Atomic Layer Deposition For Stable- And High-Performance Lifepo₄, Yan Gao, Jonghyun Park, Xinhua Liang

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Atomic layer deposition (ALD) method has emerged as a promising technique to address the dissolution and poor conductivity of electrode materials of lithium ion batteries. In this work, surface modification of LiFePO₄ (LFP) was carried out by titanium nitride (TiN) ALD, during which a Ti doping into LFP occurred simultaneously. X-ray photoelectron spectroscopy (XPS) and electrochemical tests were performed to prove the Ti doping, and the composition of TiN layer on the surface of LFP particles was interpreted as a combination of TiN and titanium oxynitride (TiO_xN_y). Owing to the synergy of TiN coating and …

Reducing Runway Incursions: The Role Of Collaboration, Education, And Training, Billy Metallinos

CUP Ed.D. Dissertations

Runway incursions are a major threat to aviation safety and can cause major delays and collisions that have significant human and financial implications for airlines. This study investigated how training, education, and collaboration may be improved to reduce the occurrence of runway incursions at airports. Data collection involved interviews, a focus group, and document analysis to explore the participants’ perceptions. The interviews and focus group involved a purposive sample of 12 pilots, air traffic controllers, airport administrators, and ground personnel. The interviews and focus group transcripts were chunked, coded, and patterns sought to form five key themes addressing the research …

Teen Driver System Modeling: A Tool For Policy Analysis, Celestin Missikpode, Corrine Peek-Asa, Daniel V. Mcgehee, James Torner, Wayne Wakeland, Robert Wallace

Complex Systems Faculty Publications and Presentations

Background: Motor vehicle crashes remain the leading cause of teen deaths in spite of preventive efforts. Prevention strategies could be advanced through new analytic approaches that allow us to better conceptualize the complex processes underlying teen crash risk. This may help policymakers design appropriate interventions and evaluate their impacts.

Methods: System Dynamics methodology was used as a new way of representing factors involved in the underlying process of teen crash risk. Systems dynamics modeling is relatively new to public health analytics and is a promising tool to examine relative influence of multiple interacting factors in predicting a health …

Effect Of Aerogel On The Thermal Performance Of Corrugated Composite Sandwich Structures, Jacob Dillon Chess

Master's Theses

Current insulation solutions across multiple industries, especially the commercial sector, can be bulky and ineffective when considering their volume. Aerogels are excellent insulators, exhibiting low thermal conductivities and low densities with a porosity of around 95%. Such characteristics make aerogels effective in decreasing conductive heat transfer within a solid. These requirements are crucial for aerospace and spaceflight applications, where sensitive components exist among extreme temperature environments. When implemented into insulation applications, aerogel can perform better than existing technology while using less material, which limits the amount of volume allocated for insulation. The application of these materials into composites can result …